United States Solid Waste and
Environmental Protection Emergency Response EPA/530-SW-90-070C
Agency (OS-305) July 1990
&EPA Report to Congress on
Special Wastes from
Mineral Processing
Summary and Findings
Methods and Analyses
Appendices
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Table of Contents
Page
Volume I: Summary and Findings
Volume II: Methods and Analyses
Chapter
1.0 INTRODUCTION
1.1 The Scope of the Mineral Processing Waste Exemption .................... 1-1
1.2 Contents and Organization ......................................... 1-3
2.0 METHODS AND INFORMATION SOURCES ................................. 2-1
2.1 EPA Data Collection Activities ...................................... 2-1
2.2 Analytical Approach and Methods ................................... 2-3
2.2.1 Waste Characteristics, Generation,
and Current Management Practices .............................. 2-4
2.2.2 Potential and Documented Danger to Human
Health and the Environment ................................ 2-6
2.2.3 Existing Federal and State Waste
Management Controls ..................................... 2-19
2.2.4 Waste Management Alternatives and
Potential Utilization ........................................ 2-21
2.2.5 Cost and Economic Impacts ................................... 2-23
2.2.6 Summary ................................................. 2-35
3.0 ALUMINA PRODUCTION ............................................... 3-1
3.1 Industry Overview ................................................ 3-1
3.2 Waste Characteristics, Generation, and Current
Management Practices ............................................. 3-2
3.3 Potential and Documented Danger to Human Health
and the Environment ............................................. 3.4
3.4 Existing Federal and State Waste
Management Controls ............................................. 3-12
3.5 Waste Management Alternatives and
Potential Utilization .............................................. 3-13
3.6 Cost and Economic Impacts ........................................ 3-14
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Table of Contents
4.0 SODIUM DICHROMATE PRODUCTION 4-1
4.1 Industry Overview 4-1
4.2 Waste Characteristics, Generation, and Current
Management Practices 4-2
4.3 Potential and Documented Danger to Human Health
and the Environment 4-4
4.4 Existing Federal and State Waste
Management Controls 4-10
4.5 Waste Management Alternatives and
Potential Utilization 4-10
4.6 Cost and Economic Impacts 4-11
4.7 Summary 4-11
5.0 COAL GASIFICATION 5-1
5.1 Industry Overview 5-1
5.2 Waste Characteristics, Generation, and Current
Management Practices 5-2
5.3 Potential and Documented Danger to Human Health
and the Environment 5-4
5.4 Existing Federal and State Waste
Management Controls 5-16
5.5 Waste Management Alternatives and
Potential Utilization 5-17
5.6 Cost and Economic Impacts 5-17
5.7 Summary 5-18
6.0 PRIMARY COPPER PROCESSING 6-1
6.1 Industry Overview 6-1
6.2 Waste Characteristics, Generation, and Current
Management Practices 6-4
6.3 Potential and Documented Danger to Human Health
and the Environment 6-8
6.4 Existing Federal and State Waste
Management Controls 6-42
6.5 Waste Management Alternatives and
Potential Utilization 6-44
6.6 Cost and Economic Impacts 6-51
6.7 Summary 6-61
7.0 ELEMENTAL PHOSPHORUS PRODUCTION 7-1
7.1 Industry Overview 7-1
7.2 Waste Characteristics, Generation, and Current
Management Practices 7-3
7.3 Potential and Documented Danger to Human Health
and the Environment 7-3
7.4 Existing Federal and State Waste
Management Controls 7-17
7.5 Waste Management Alternatives and
Potential Utilization 7-18
7.6 Cost and Economic Impacts 7-22
7.7 Summary 7-22
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Table of Contents iii
8.0 FERROUS METALS PRODUCTION 8-1
8.1 Industry Overview 8-1
8.2 Waste Characteristics, Generation, and Current
Management Practices 8-5
8.3 Potential and Documented Danger to Human Health
and the Environment
8.4 Existing Federal and State Waste
Management Controls ".
8.5 Waste Management Alternatives and
Potential Utilization 8-37
8.6 Cost and Economic Impacts 8-39
8.7 Summary 8-48
9.0 HYDROFLUORIC ACID PRODUCTION 9-1
9.1 Industry Overview 9-1
9.2 Waste Characteristics, Generation, and Current
Management Practices 9-2
9.3 Potential and Documented Danger to Human Health
and the Environment 9-5
9.4 Existing Federal and State Waste
Management Controls 9-18
9.5 Waste Management Alternatives and
Potential Utilization 9-20
9.6 Cost and Economic Impacts 9-21
9.7 Summary 9-25
10.0 PRIMARY LEAD PROCESSING 10-1
10.1 Industry Overview 10-1
10.2 Waste Characteristics, Generation, and Current
Management Practices 10-3
10.3 Potential and Documented Danger to Human Health
and the Environment 10-5
10.4 Existing Federal and State Waste
Management Controls 10-26
10.5 Waste Management Alternatives and
Potential Utilization 10-28
10.6 Cost and Economic Impacts 10-33
10.7 Summary 10-41
11.0 MAGNESIUM PRODUCTION ll-l
11.1 Industry Overview 11-1
11.2 Waste Characteristics, Generation, and Current
Management Practices 11-3
11.3 Potential and Documented Danger to Human Health
and the Environment 11-4
11.4 Existing Federal and State Waste
Management Controls 11-8
11.5 Waste Management Alternatives and
Potential Utilization 11-9
11.6 Cost and Economic Impacts 11-9
11.7 Summary 11-14
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iv Table of Contents
12.0 PHOSPHORIC ACID PRODUCTION 12-1
12.1 Industry Overview 12-1
12.2 Waste Characteristics, Generation, and Current
Management Practices 12-3
12.3 Potential and Documented Danger to Human Health
and the Environment 12-5
12.4 Existing Federal and State Waste
Management Controls 12-32
12.5 Waste Management Alternatives and
Potential Utilization 12-36
12.6 Cost and Economic Impacts 12-47
12.7 Summary 12-58
13.0 TITANIUM TETRACHLORIDE PRODUCTION 13-1
13.1 Industry Overview 13-1
13.2 Waste Characteristics, Generation, and Current
Management Practices 13-3
13.3 Potential and Documented Danger to Human Health
and the Environment 13-5
13.4 Existing Federal and State Waste
Management Controls 13-20
13.5 Waste Management Alternatives and
Potential Utilization 13-22
13.6 Cost and Economic Impacts 13-23
13.7 Summary 13-29
14.0 PRIMARY ZINC PROCESSING 14-1
14.1 Industry Overview 14-1
14.2 Waste Characteristics, Generation, and Current
Management Practices 14-2
14.3 Potential and Documented Danger to Human Health
and the Environment 14-4
14.4 Existing Federal and State Waste
Management Controls 14-17
14.5 Waste Management Alternatives and
Potential Utilization 14-18
14.6 Cost and Economic Impacts 14-20
14.7 Summary 14-25
GLOSSARY G-l
Volume III: Appendices
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REPORT TO CONGRESS
ON
SPECIAL WASTES FROM MINERAL PROCESSING
Summary and Findings
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Chapter 2: Methods and Information Sources 2-37
Step 3. What would be the operational and economic consequences of a decision to
regulate a special waste under Subtitle C?
If, based upon the previous two steps, EPA believed that regulation of a waste under Subtitle C might
be appropriate, then the Agency evaluated the costs and impacts of two regulatory alternatives that are based
upon Subtitle C, and one alternative that reflects one possible approach that might be taken under RCRA
Subtitle D. The focus of this inquiry was whether the magnitude and distribution of regulatory compliance
costs might jeopardize the continued economic viability of one or more generators if the waste were to be
regulated under the Subtitle C regulatory scenario. The key questions in the Agency's decision-making process
were as follows:
1. Are predicted economic impacts associated with the Subtitle C scenario significant for any of
the affected facilities?
2. Are these impacts substantially greater than those that would be experienced under the
Subtitle D-Plus scenario?
3. What is the likely extent to which compliance costs could be passed through to input and/or
product markets, i.e., to what extent could regulatory cost burdens be shared?
4. In the event that significant impacts are predicted, might a substantial proportion of domestic
capacity or product consumption be affected?
5. What effects would hazardous waste regulation have upon the viability of the beneficial use or
recycling of the special waste?
In ERA'S judgment, absence of significant impacts or high pass-through potential suggested that Subtitle C
regulation might be appropriate for wastes that pose significant risk. In cases in which even relaxed Subtitle C
standards would impose widespread and significant impacts on facilities, and/or deter the safe and beneficial
use of the waste, EPA concluded that regulation under some form of Subtitle D program might be more
appropriate.
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Chapter 2: Methods and Information Sources 2-35
Based on both quantitative and qualitative assessments of the available industry and market
information, EPA estimated the most likely incidence of compliance costs across the following market
segments:
Segment
Regulated Industry
Labor
Supplying Industries
Intermediate U.S Product
Markets
Final U.S. Markets
Foreign Markets
Type of Impact
Lower Profits
Lower Wages/Fewer Jobs.
Lower Input Prices/Smaller
Markets
Higher Product Prices
Higher Product Prices
Higher Product Prices
In general, the type of impact in the regulated industry involves higher costs and lower profits,
including the possibility of continual negative profits and associated plant closures. The type of impact in
other segments involves adverse changes in market prices (higher prices for buyers and lower prices for sellers
of mineral processing inputs) and reductions in market size.
The levels of impacts were assessed on the basis of relatively near-term changes in market conditions.
For example, the ability of the affected firms to pass-through compliance costs in the form of higher product
prices would be shown to mitigate the direct impact of the proposed rule on the regulated industry. The
possibility th:.: higher U.S. prices might then attract new foreign competit n, increase imports, and eventually
result in lower U.S. product prices has not been factored into EPA's ana .-sis.
2.2.6 Summary
Based upon the analysis of the study factors found at §8002(p) as described above, EPA has arrived
at preliminary findings that are relevant to the appropriate regulatory status under RCRA of the special wastes
from mineral processing. These findings were arrived at through an explicit evaluation process, which is
described below. In this process, the Agency considered the study factors in a step-wise fashion, first assessing
the need for additional regulatory controls (or absence thereof), then evaluating the options for appropriate
requirements that could be applied to each individual waste stream for which additional controls might be in
order. In applying this framework, EPA has employed a number of assumptions, which are described in the
following paragraph. Each sector-specific chapter in this volume concludes with a summary that highlights
the major findings of this study for the waste(s) of interest, organized by the issues presented in sequence
below. EPA's preliminary conclusions regarding the appropriate regulatory status of each special mineral
processing waste are presented in Volume I of this report.
The first assumption that the Agency has employed is that explicit decision criteria were needed and
should be applied uniformly to all of the special study wastes. In this manner, consistent and reasonable
decisions regarding the need for additional regulatory controls can be achieved. The second major assumption
guiding EPAs decision-making process was that the study factors that are most important in establishing the
regulatory status of the special wastes are risks posed and documented damages caused by the wastes, and the
costs and impacts that would be associated with more stringent regulatory controls. The reason for this is that
in the absence of potential risk and/or documented damages, there is no need for hazardous waste regulation
under RCRA Subtitle C (the key issue in question); if greater regulatory controls are needed because of
significant potential or documented danger, the costs and impacts of regulatory controls are the critical factor
in determining whether a given alternative would lead to the desired outcome (adequate protection of human
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2-36 Chapter 2: Methods and Information Sources
health and the environment, and continued operation of the affected industries). EPA also believes that it
has developed and analyzed regulatory compliance scenarios that are realistic from an operational and
engineering standpoint, and that are likely to be adequately protective of human health and the environment.
i.e., could be implemented by facility operators and would result in societal benefits. Finally, because the waste
management controls that might be imposed under the auspices of Subtitle D or developed under the
regulatory flexibility provided by RCRA §3004(x) are not well-defined at this juncture, the focus of EPA's
comparisons of the desirability of Subtitle C and Subtitle D regulation has been on the full Subtitle C and
Subtitle D-Plus scenarios, rather than on Subtitle C-Minus and baseline conditions. Nonetheless, because of
the high volume nature of the special mineral processing wastes, EPA believes that an effective and
appropriate regulatory program for the management of these materials should be tailored to reflect their
unusual characteristics; the Agency's preliminary assessment of how these programs might be tailored in this
way is reflected in the Subtitle C-Minus and Subtitle D-Plus scenarios described in the previous section.
Evaluation Criteria
Step 1. Does management of this waste pose human health/environmental problems ? Might
current practices cause problems in the future?
Critical to the Agency's decision-making process is whether each special waste either has caused or
could cause human health or environmental damage. To resolve this issue, EPA has posed the following key
questions:
1. Has the waste, as currently managed, caused documented human health impacts or
environmental damage?
2. Does EPAs analysis indicate that the waste could pose significant risk to human health or the
environment at any of the sites that generate it (or in off-site use), under either current
management practices or plausible mismanagement seen -ios?
3. Does the waste exhibit any of the characteristics of hazardous waste?
If the answer to any of these three questions was yes, then EPA concluded that further evaluation was
necessary. If the answer to all of these questions was no, then the Agency concluded that regulation of the
waste under RCRA Subtitle C is unwarranted.
Step 2. Is more stringent regulation necessary and desirable?
If the waste has caused or may cause human health or environmental impacts, then EPA concluded
that an examination of alternative regulatory controls was appropriate. Given the context and purpose of the
present study, the Agency focused on an evaluation of the likelihood that such impacts might continue or arise
in the absence of Subtitle C regulation, by posing the following three questions:
1. Are current practices adequate to limit contaminant release and associated risk?
2. What is the likelihood of new facilities opening in the future and generating and managing the
special waste in a different environmental setting than those examined for this report?
3. Are current federal and state regulatory controls adequate to address the management of the
waste?
If current practices and existing regulatory controls are adequate, and if the potential for actual future impacts
is low (e.g., facilities in remote locations, low probability of new facilities being constructed), then the Agency
tentatively concluded that regulation of the waste under Subtitle C is unwarranted. Otherwise, further
examination of regulatory alternatives was necessary.
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Chapter 2: Methods and Information Sources 2-33
Data Sources
The U.S. Bureau of Mines provided most of the industry and market data on which EPA has based
its assessment of the economic conditions facing each mineral commodity sector. The Minerals Yearbook 1987
and Mineral Commodity Summaries 1989 are the major published sources of data from the Bureau of Mines,
but additional BOM data were obtained from contacts with the Bureau's Mineral Commodity Specialists. Data
from the Technical Background Document18 and trade journals, including Chemical
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2-34 Chapter 2: Methods and Information Sources
Exhibit 2-8
Indicators of Significant Economic Impact
Screening Index
Compliance Costs as Percent of Sales
Compliance Costs as Percent of Value Added
Capital Investment Requirements as Percent of
Current Capital Outlays
Symbol
cc/vos
CC/VA
IR/K
Description
Percent by which product price would need to in-
crease to maintain current production and profits with
compliance
Percent reduction in value added due to outlays for
compliance
Percent of current capital expenditures that would
need to be diverted to compliance uses if total
capital outlay remained constant
In all cases, the ability to pass through compliance costs depends on the initial incidence of compliance costs
within the affected sector and the concentration and interdependency of buyers and sellers in relevant input
and product markets.
The price sensitivity of buyers and sellers in relevant markets cannot be estimated precisely but
enough information is available about industry and market conditions and relevant market trends to assess the
most likely distribution of economic impacts. For example, current wages and salary data can give an
indication of whether some firms may be able to pass compliance costs back to labor. For purposes of
analysis, information about factor and product markets related to each a ected mineral processing sector has
been organized on the basis of the following criteria:
MARKET CONCENTRATION
• Affected sectors as sellers in U.S. and world markets
• Affected sectors as buyers of inputs and labor
INTERINDUSTRY DEPENDENCE
• Availability/cost of alternatives
• Availability/cost of substitutes
INDUSTRY/MARKET TRENDS
• U.S. mineral production and consumption
• Global mineral production and consumption
• U.S. mineral imports and exports
VALUE ADDED
• Contribution of material and processing costs to the price of fabricated/manufactured
product
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Chapter 2: Methods and Information Sources 2-31
EPA has estimated the costs of waste management for each individual facility that may be affected
by new regulatory requirements for up to four waste management scenarios. Cost equations developed from
an engineering analysis of each technology are used to estimate the costs for each individual management
practice used. The sum of the costs equals the total facility cost. Under three alternative regulatory scenarios
examined here, four types of costs can be incurred:
• Capital investment costs, both direct and indirect, incurred initially and in each year that
the technology is operated (e.g., construction of new disposal units). Capital costs
incurred annually are treated as operating costs;
• Annual operating and maintenance (O&M) costs, both direct and indirect (e.g.,
materials, labor, utilities);
• Capital costs (direct and indirect) for facility closure; and
• Annual costs of post-closure care and maintenance.
Most of the facilities of interest are not currently required to perform formal closure and post-closure care
activities. Accordingly, in EPAs analysis, most facilities are assumed to experience only capital and O&M
costs under the baseline scenario.
Costing Equations
EPA has developed cost estimating equations that reflect the current waste management practices
employed by the facilities of interest, as well as the practices that would be required under alternative
regulatory scenarios. In analyzing each facility, total management costs are built up by determining which
specific requirements apply (e.g., obtaining permits, installing run-on/run-off controls, constructing a tank
treatment system), estimating the cost of each requirement for a given waste stream at the facility, and adding
the costs of each requirement. EPA used these technology-specific costs to calculate the total annual
compliance costs (ACCs) for utilizing a given management requirement The ACC for a waste management
practice is the sum of the ACCs for the treatment, storage, and dispo jl steps in that waste management
practice. In this way, all costs of currently used management techniques are accounted for, and only the items
that would actually apply at a particular facility are used in calculating incremental waste management costs.
Analytical Assumptions
In general, most of the waste streams considered in this report do not exhibit characteristics of
hazardous waste. In conducting this cost analysis, EPA has assumed that waste streams are potentially
hazardous at individual plants only if data submitted by industry or EPA sampling indicate failure of hazardous
waste characteristic tests, for most waste streams.17 In these cases, the waste(s) are assumed to be candidates
for Subtitle C and Subtitle C-minus regulation, and are examined in the cost analysis on that basis. Otherwise,
wastes are assumed to be non-hazardous, except for waste streams which may pose risks that are not addressed
by current Subtitle C hazardous waste characteristics tests (e.g., radioactivity), or for which special
circumstances justify a modified cost analysis approach.
For those wastes assumed to be candidates for regulation under one or more alternative scenarios,
it is often the case that more than one management train would be available. In these instances, and in
keeping with the profit-maximizing behavior expected of facility operators, the Agency selected the least-cost
alternative for managing each waste under each regulatory scenario. The costs of each scenario/least-cost
management practice combination were then compared to the estimated cost of current management practices,
in order to develop incremental regulatory compliance costs.
1 The preponderance of evidence indicates that a small number of wastes are likely to exhibit hazardous characteristics at most
(including unsampled) facilities; in its costing analysis, EPA has assumed that these wastes would exhibit characteristics of hazardous waste
at all facilities unless actual sampling data indicated a contrary result.
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2-32 Chapter 2: Methods and Information Sources
In estimating costs for specific waste management technologies, the Agency made a number of costing
assumptions, which are described in Appendix E-3 to this report. Detailed results of EPA's compliance cost
analysis are presented in a technical background document that may be found in the supporting docket for
this report.
Evaluation of Economic impact
Section 8002(p) requires that EPA examine, in addition to incremental costs, the impacts of waste
management alternatives on the use of natural resources, and, by implication, the entities (firms) that would
be subject to new waste management requirements. If subjected to new regulatory requirements, firms in
affected mineral processing sectors will incur compliance costs which will generate both direct and indirect
economic impacts. Direct impacts on the company include lower profits and the reduced value of assets
because of anticipated reductions in future profits. Indirect impacts are associated with the "pass through" of
compliance costs either backwards in the form of lower wages paid to workers and/or lower prices paid to
suppliers, or forward in the form of higher prices charged to customers. Additional direct and indirect impacts
on the local or national economy are associated with the possibility of plant closures and associated job and
income losses, reductions in federal, state, and county tax revenues, possible changes in the U.S. balance of
trade, and increased reliance on foreign sources for critical mineral supplies.
EPA's economic impact assessment of prospective requirements has two parts. First, the Agency put
the compliance costs for each affected commodity sector into context by comparing them with other cost and
sales figures for the sector. The Agency considered compliance costs to be possibly significant and requiring
further evaluation if they were greater than or equal to:
• 1 percent of sales and/or value added;
• 5 percent of current capital outlays i.e., sustaining capital (based on capital compliance
costs).
The data used to apply these screening tests are based on standard accounting measures of cost and financial
performance, and in general were obtained from published sources. Throughout, EPA has conducted its
analysis on a facility-specific basis.
When EPA determined that compliance costs for a facility or mineral processing sector exceeded the
screening threshold value for at least two of the indices, the Agency examined the competitive position of
affected firms within the sector and conditions in relevant input and product markets to assess the ability of
affected firms to pass through compliance costs to workers, to suppliers, and to customers, including foreign
markets. The Agency based this assessment on information about industry and market trends, buyer and seller
concentration, and inter-industry dependencies. Where the possible pass-through of compliance costs was to
other sectors of the U.S. economy, they were viewed as transfers of economic impacts or shifts in the
"incidence" of compliance costs; where the pass-through was to foreign markets EPA viewed them as potential
reductions in U.S. compliance costs and economic impacts.
The following paragraphs describe the data sources that EPA used to characterize the financial
performance and industry and market characteristics for each mineral commodity sector. Then, the Agency
discusses the methodology for evaluating the significance of compliance costs for each sector and for assessing
the most likely distribution of compliance costs across market levels. The sector-specific discussions that
follow this chapter provide economic profiles of each affected industrial sector, including information about
product markets, input factor markets, and trends in production and consumption.
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Chapter 2: Methods and Information Sources 2-29
regarding the development and application of the Subtitle C-Minus scenario to individual waste streams and
facilities is provided in Appendix E-3 to this report,
Subtitle D-Plus Scenario
The third and final regulatory alternative considered by the Agency for this analysis of regulatory costs
and impacts is regulation under one possible approach to a RCRA Subtitle D (solid, non-hazardous waste)
program. The approach described here has been developed solely for analytical purposes by EPA staff, and
is tailored to address some of the special characteristics of mineral processing wastes. The reason for inclusion
of a Subtitle D scenario in this report is that the Agency is presently developing a tailored program to address
mineral extraction and beneficiation wastes under Subtitle D, and could consider applying this program to any
of the 20 mineral processing wastes that remain excluded from regulation under RCRA Subtitle C after the
regulatory determination that will follow, and be based upon, this report and on changes made due to
comments received from the public and inter-agency discussions.
Substantively, the Subtitle D-Plus program would be a state-implemented program based on a
minimum set of federal technical criteria and provisions for state program primacy. The technical criteria
contained within the program would consist essentially of provisions for the state establishment of media-
specific performance standards for ground water, surface water, air, and soils/surficial materials. The Subtitle
D-Plus scenario also contains technical criteria for a variety of required owner/operator activities, including
design and operating criteria, monitoring criteria, corrective action requirements, closure and post-closure care
criteria, and financial responsibility requirements. These prospective regulatory provisions are summarized
in Appendix E-2 to this document. The Agency has also identified and categorized all provisions of the
Subtitle D-Plus scenario having potential cost implications. These groups of requirements are listed in
Exhibit 2-7 and serve as the starting point for EPA's compliance cost analysis. Additional detail regarding the
manner in which these requirements have been applied to individual facilities is provided in Appendix E-3 to
this document.
Costing Assumptions and Methods
This section provides a brief overview of the methodology and assumptions that EPA has used to
estimate compliance costs for regulation of special mineral processing wastes under the four regulatory
scenarios described above.
Costs of regulations can be viewed in two contexts, economic and financial. The two contexts consider
regulatory costs in two very different ways for different purposes. The economic context considers impacts on
society at large, while the financial context evaluates effects on firms, facilities, and other discrete entities. For
this report, EPA has considered only the financial context, that is, impacts on firms and facilities. Thus, in
keeping with the statutory directives articulated at RCRA §8002(p), EPAs analysis employs a financial
perspective which attempts to evaluate the actual costs that would be incurred by those firms subject to
regulation. The willingness and ability of firms to comply with the regulations (instead of discontinuing the
regulated activity) are influenced by the magnitude and timing of compliance costs, market and competitive
factors, and firm-specific financial considerations, such as the costs incurred by the firms to obtain capital.
Consequently, in conducting this analysis, EPA has employed data and assumptions that reflect the
focus on the individual facility/firm. For example, the Agency has employed a discount rate that approximates
the likely true cost of obtaining financing for regulatory compliance-related expenditures, rather than a "social"
discount rate, or cost to society, and has computed costs on an after-tax basis, to better reflect the financial
impacts that might be imposed by new regulatory requirements.
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2-30 Chapter 2: Methods and Information Sources
Exhibit 2-7
Regulatory Requirements: Subtitle D-Plus Program Scenario
Category
Requirement
Regulated Materials Characterization
Regulated Materials Characterization
Deaign and Operating Criteria
Structural Stability
Run-on/Run-off Controls
Land Application Requirements
Biological Resources Protection
Site Access Control
Inspections
Location Standards:
Floodplains
Seismic Zones, Unstable/Fault Areas
Karst Terrane
Wellhead Protection Areas
Unit-Specific Requirements:
Waste Piles
Landfills
Surface Impoundments
Gypsum Stack*
Tank Treatment System*
Monitoring
Ground-Water Monitoring
Surface Water Monitoring
Air Monitoring
Corrective Action
Closure
Corrective Action Plan
Corrective Action Activities:
Source Control
Remediation
Final Regulated Materials Characterization
Continued Compliance with Design and Operating Criteria
Closure Plan
Closure Activities
Run-on/Run-off Control*
Stabilization/Neutralization
Wind Dispersal Control
Removal of Material*, Decontamination (Tank*)
Poel-Ooeure Care
Continued Compliance with Design and Operating Criteria
Post-Closure Care Plan
Poet-Closure Car* Activities
Maintenance of Closur* Activities
Financial Responsibility
Environmental Impact Liability
Corrective Action
Clo*ur*/Po*t-Clo*ure Car*
Cost Estimating Methods
In EPA's cost estimating analysis, the first step was to estimate the costs of waste management
activities and the distribution of these costs over time. The second step was to discount all future costs to the
present and then calculate the equivalent annualized compliance cost (ACC), incorporating the specific
requirements of the context being examined. The annualized compliance cost is the average annual cost
(annuity) over the life of the facility that has the same total present value as the actual expenses incurred at
their actual times. This method offers the distinct advantage of allowing comparisons between scenarios and
among industrial sectors that may incur compliance costs of different types and/or at different times.
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Chapter 2: Methods and Information Sources 2-27
impose new costs on the operators of the mineral processing facilities considered in this study. These groups
of cost-related requirements are listed in Exhibit 2-6 and serve as the starting point for EPAs compliance cost
analysis. Additional detail' regarding the manner in which EPA has computed the costs of these individual
provisions is provided in Appendix E-3.
Subtitle C-M/nus Scenario
Tb assess the potential costs and impacts of less stringent regulation, EPA has evaluated an
intermediate Subtitle C scenario ("Subtitle C-Minus") that assumes that EPA exercises all of the regulatory
flexibility provided by Section 3004(x) of RCRA. Section 3004(x) does not give EPA authority to waive
Subtitle C requirements based on cost alone. Rather, this provision allows EPA to provide some regulatory
flexibility to mitigate the economic impacts of Subtitle C regulation on the industries generating certain special
wastes, provided that adequate protection of human health and the environment is ensured. This flexibility
allows EPA to modify the relevant provisions to take into account the special characteristics of (in the current
context) mineral processing wastes, practical difficulties in implementing the specific RCRA Subtitle C
requirements, and site-specific characteristics.
For purposes of estimating the costs of this regulatory alternative in this Report to Congress. EPA
has identified and evaluated what it believes would be the minimum allowable extent of regulation under
Subtitle C (i.e., the maximum allowable application of regulatory flexibility) that comports with the statutory
requirement of ensuring adequate human health and environmental protection. EPA stresses, however, that
the hypothetical Subtitle C-Minus scenario analyzed here does not reflect the Agency's actual determination
as to which Subtitle C requirements might be altered and to what extent through the 3004(x) mechanism for
any of the wastes or industries studied in this report, though it does reflect an attempt to craft tailored
Subtitle C requirements that are operationally and economically feasible at the facility level. Moreover, EPA
believes that the scenario provides a meaningful "lower bound" for estimating the potential compliance costs
that would be imposed under Subtitle C. In other words, estimated Subtitle C-Minus compliance costs and
associated impacts are likely to understate the actual impacts that would be imposed if the special mineral
processing wastes are withdrawn from the Mining Wfcste Exclusion, at k jt for some commodity sectors and
facilities.
This scenario uses many of the same assumptions as the full Subtitle C regulatory scenario, with three
notable exceptions:16
The prohibition on placing liquids in Subtitle C landfills does not apply;
• Land Disposal Restrictions do not apply, and
• On-site waste management practices, for special mineral processing wastes meet only
pre-HSWA Subtitle C technological requirements, rather than the minimum technology
required under 3004(o) and 3005(j) of the amended RCRA statute.
Potentially hazardous wastes managed on-site are awarded this regulatory flexibility. Candidate
Subtitle C wastes managed off-site, however, are assumed to be sent to facilities that comply with all provisions
of Subtitle C. Most other assumptions made for the full Subtitle C regulatory scenario with respect to the
choice of waste management technologies apply to the Subtitle C-minus regulatory scenario as well.
Nonetheless, one important aspect of the way in which EPA has evaluated the implications of RCRA
§3004(x) is that site-specific variability in risk potential and waste-specific variability in existing management
practices has been explicitly factored into the analysis. Subtitle C-Minus waste management requirements are
less stringent at facilities at which the potential for contaminant release and transport are low than at facilities
at which such potential is high. For example, all else being equal, requirements at a facility overlying shallow
ground water with high local net recharge and porous soils are more stringent than at an otherwise similar
facility located in an arid region with deep ground water and relatively impermeable soils. Additional detail
k*As explained further below, EPA has not estimated corrective action costs in preparing this report, though relaxation of corrective
action requirements is a potentially significant aspect of RCRA §3004(x)
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2-28 Chapter 2: Methods and Information Sources
Exhibit 2-6
Regulatory Requirements: Subtitle C Scenario
Category
RCRA §3010 Notification
Permit Requirements
Preparedness and Prevention
Design and Operating Criteria
Monitoring
Corrective Action
Closure
Post-Closure Care
Financial Responsibility
Requirement
• Notification
• Exposure Potential Information
• Chemical and Physical Analysis of Waste(s)
• Waste Analysis Plan
• Site Security
• Inspections
• Location Standard Studies
• Topographical Map
• Ground-Water Protection Study
• Internal Communication/Alarm System
• Water Sprinkler System
• Land Disposal Restrictions
• Tank Requirements:
Secondary Containment
Construction Requirements
• Surface Impoundment Requirements:
Existing - Liner or No Migration Demonstration
New - Double Liner, Leachate Collection System
• Waste Pile Requirements:
Liner
Leachate Collection and Removal System
Run-on/Run-off Contrc's
Wind Dispersal Contrc ,
• Landfill Requirements:
Existing - Liner and Leachate Collection System
New - Double Liner, Dual Leachate Collection System
Run-on/Run-off Controls
Wind Dispersal Control
• Land Treatment Requirements:
Proof of Contaminant Degradation, Transformation, or
Immobilization
Run-on/Run-off Controls
Wind Dispersal Control
Permit for Field and Greenhouse Testing
Soil/Liquid Monitoring
Crop Distribution Plan
• Ground-Water Monitoring
• Corrective Action Plan
• Corrective Action Activities
Source Control
Remediation
• Remove/Decontaminate Residues
• Stabilize, Cover Waste(s)
• Monitoring
• Maintenance
• Leachate Collection
• Run-on/Run-off Control
• Environment Impairment Liability
• Sudden Release of Contaminants
• Non-Sudden Release of Contaminants
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Chapter 2: Methods and Information Sources 2-25
waste categories.14 Under this provision, many significant RCRA requirements15 for wastes may be
modified
"...to take into account the special characteristics of such wastes, the practical
difficulties associated with implementation of such requirements, and stte-
specific characteristics, including but not limited to the climate, geology,
hydrology and soil chemistry at the site, so long as such modified requirements
assure protection of human health and the environment."
Costs associated with the remaining regulatory alternative, the "Subtitle D-Plus" management program,
on the other hand, are intended to be illustrative only. Although EPA is in the process of developing a
Subtitle D program for mineral extraction and beneficiation wastes, the specific elements of this program
remain to be determined. Whether and to what extent the ultimate mining wastes regulatory program
resembles the Subtitle D-Plus regulatory scenario described here cannot be known at this juncture. EPA has,
nonetheless, estimated the costs and impacts of Subtitle D regulation of special mineral processing wastes in
this report, in the expectation that some of these studied wastes may ultimately be regulated under the
Subtitle D mining wastes program, in whatever form it is finally promulgated.
Management costs associated with each pertinent regulatory scenario are estimated for each facility
being analyzed by identifying the specific items (and their costs) that are currently employed (in the baseline
case) and that would be required under the regulatory alternatives. EPA utilized data contained in facility
responses to the 1989 SWMPF survey to characterize current practices. The Agency then calculated the costs
associated with each practice employed (e.g., design, construction, and operation of an unlined surface
impoundment, waste stabilization, installation and operation of ground water, surface water, and/or air
monitoring equipment); the sum of these costs is the total management cost at a given facility.
This technology- and facility-specific approach has resulted in management cost estimates that vary
widely among facilities, even among those in the same commodity sector. For example, EPAs cost estimates
for baseline practices account for the presence of waste management controls such as run-on and run-off
control systems and ground water monitoring. Facilities that currently mploy these controls have higher
current (baseline) waste management costs (all else being equal) than facilities that do not Consequently,
prospective Subtitle C regulation, and its attendant technical requirements (e.g., run-on and run-off controls,
ground water monitoring) have reduced compliance cost implications at such facilities. Because EPA's cost
analysis relies upon individual cost elements rather than unified cost functions, this variability in current waste
management cost and, therefore, the incremental waste management cost associated with regulatory
alternatives, can be accounted for in full.
Base/me Scenario
The baseline regulatory scenario assumes that existing waste management practices will remain
unchanged. The waste management practices discussed in the sector-specific chapters that follow comprise
the waste management technologies employed under this scenario. In virtually all cases, assumed current waste
management practices are based upon information submitted to EPA in the form of responses to the 1989
National Survey of Solid Wastes from Mineral Processing Facilities, supplemented by information obtained
during visits to some facilities. In the few instances in which management practice information was missing
or incomplete, the Agency assigned one or more management technologies based upon knowledge of the
common practices used by other similar (e.g., same commodity sector and size of operation) facilities.
14 Specifically, cement kiln dust waste and Qy ash, bottom ash, slag, and flue gas emission control wastes generated primarily from
combustion of fossil fuels (principally coal).
15 Specifically, RCRA sections 3004(c) through (g) (land disposal restrictions), (o) (minimum technology standards), (u) corrective
action for continuing releases), and 3005(j) (permitting of interim status treatment, storage, and disposal surface impoundments).
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2-26 Chapter 2: Methods and Information Sources
The most common current waste management technologies for solid and some sludge materials include
on-site, unlined landfills; waste piles without a cover or a base; gypsum stacks; and recycling. Wastewaters
tend to be managed in on-site, unlined surface impoundments (some in combination with a gypsum stack).
and in a few cases, synthetic- or clay-lined surface impoundments. Some portion of these wastewater streams
is recycled at nearly all facilities.
Several of the facilities examined here, particularly in the ferrous metals commodity sector, already
are interim status or permitted Subtitle C Treatment, Storage, and Disposal Facilities (TSDFs). Such facilities
are already subject to many of the requirements that are evaluated in this report (e.g., Subtitle C permitting.
financial assurance, corrective action for continuing releases requirements), and hence, would not experience
incremental compliance costs associated with these specific regulatory requirements if the special waste(s) that
they generate were to be removed from the Mining Waste exclusion. EPA has, accordingly, reflected this fact
in conducting its cost and economic impact analysis.
The "Baseline" scenario for the industry sectors covered by this report would occur under a regulatory
determination by EPA that the special mineral processing wastes that are currently excluded from regulation
under Subtitle C of RCRA do not require regulation as hazardous wastes. Even with such a regulatory
determination, however, some changes in waste management practices may be required. The mineral
processing industry, which has historically been exempt from the federal hazardous waste management
regulations under RCRA, has recently had this protection removed by a series of EPA nilemakings that were
concluded on January 23, 1990 (55 FR 2322). As of the effective date of this latest rulemaking, all mineral
processing wastes except the 20 specific wastes considered in this report are subject to regulation as hazardous
wastes (i.e., under RCRA Subtitle C) if they exhibit one or more characteristics of hazardous waste. In
addition, six mineral processing wastes have been listed as hazardous wastes (see 53 FR 35412, September 13,
1988). EPA believes that many of the facilities considered in this report generate wastes that are newly subject
to these requirements. Consequently, existing "baseline" management practices that are currently applied to
special wastes at some of these facilities may change even if these materials are not removed from the Mining
Waste Exclusion.
In addition, several states have imposed or are in the process of in nosing new regulatory requirements
on the operators of mineral processing facilities. For example, the S:ate of Florida has issued a policy
directive requiring that all new phosphogypsum stacks or lateral expansions of existing stacks have a clay liner;
the State Department of Environmental Regulation has also indicated that it plans to initiate a formal
rulemaking process for the development of phosphogypsum management regulations.
In general, however, the scope of EPA's analysis is limited to an examination of special mineral
processing waste management as it is currently conducted, that is, as reported by facility operators in the 1989
SWMPF Survey. Nonetheless, where appropriate, the Agency has indicated when and in what manner existing
management practices are expected to change because of non-RCRA federal or state-level regulatory activity.
Full Subtitle C Scenario
The full Subtitle C ("Subtitle C") scenario examined here for the special wastes is based on the
premise that any of the 20 wastes for which (1) existing practices have been shown to have caused
environmental damages, or (2) have exhibited risk in the risk assessment process described above, including
any that exhibit one or more RCRA hazardous characteristics (EP-toricity, corrosivity, ignitability, or
reactivity) may be regulated under Subtitle C and, thus, subject to the technical requirements of 40 CFR Part
264. The remaining wastes, which have not shown significant potential risk or documented damages and do
not exhibit a hazardous characteristic, are assumed to not be candidates for Subtitle C (or Subtitle C-minus)
regulation, and hence, have not been analyzed under these scenarios.
EPA has examined the full array of Subtitle C regulatory requirements, and has identified those that
would be relevant from the standpoint of managing mineral processing wastes (some Subtitle C requirements,
such as those addressing the management of used oil, solvents and dioxins, etc. are clearly not germane to the
present study). Relevant regulatory provisions are summarized in Appendix E-l to this document. The
Agency then identified and categorized all of these requirements that might have cost implications. In other
words, the focus of EPA's compliance cost analysis is on the specific regulatory requirements that would
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Chapter 2: Methods and Information Sources 2-23
within the documents was supplemented by reviewing the 1989 National Survey of Solid Wastes from Mineral
Processing Facilities (SWMPF Survey), and through direct contacts with private industry, trade associations,
government agencies, contractors, and researchers.
More than 3,000 documents were identified as being potentially useful, primarily as a result of key
word searches. A number of criteria were used to critically evaluate the 3,000 references and reduce.the
number of documents actually obtained and reviewed. Documents having titles with no clear relationship to
any of the RTC study factors were eliminated from the Agency's preliminary list of potential information
sources. EPA set priorities for procurement of the remaining documents after reviewing their abstracts (or
key word descriptors if an abstract was not available), the time for delivery, and cost. Out of the possible 3,000
documents, over 300 were received and reviewed.
Additional information has been obtained through direct contact with Commodity Specialists and
researchers at the U. S. Bureau of Mines, trade associations (e.g., the Florida Institute of Phosphate Research.
The Fertilizer Institute), university researchers, and companies with some involvement in the management or
utilization of one or more of the special study wastes. A comprehensive list of references that were collected
and used by EPA in preparing this report may be found in Appendix B-5.
Evaluation ol Alternatives
At a minimum, EPA's evaluation of each option includes a brief description of what the option
involves (e.g., processing steps, equipment, and transportation); what is known about the current and potential
use of the alternative; a discussion of the factors relevant to its regulatory status; and a discussion of the
alternative's feasibility with respect to its cost and/or social acceptability. (The term "social acceptability" refers
to whether an alternative is perceived to pose a potential threat to human health or the environment. Even
in the absence of supporting data, perceived threats can influence the decisions of regulators, waste generators,
and panics that might utilize a waste material.)13 Where the information available allows, the discussion has
been expanded to include data on costs, waste generation rates, and the chemical and physical characteristics
of any waste management/ utilization residues. In many instances, the available data were not sufficient to
allow EPA to evaluate the human health and environmental protection p >vided by the waste utilization and
management alternatives identified. As a result, discussion of these options does not imply that EPA endorses
their use.
2.2.5 Cost and Economic Impacts
Section 8002(p) of RCRA requires EPA to analyze "alternatives to current disposal methods" for solid
wastes generated from the extraction, beneficiation, and processing of ores and minerals. EPA is also required
to analyze "the costs of such alternatives." This section discusses methods for evaluating the costs and
associated economic impacts of alternative waste management practices for the twelve mineral processing
industry sectors and 20 special mineral processing wastes covered in this report. The analysis of costs and
impacts is limited in scope to those waste streams that are candidates for regulation under Subtitle C of
RCRA, i.e., those that exhibit one or more characteristics of hazardous waste and/or that have been associated
with documented cases of danger to human health or the environment
Costs may be imposed upon facility operators if changes in the regulatory requirements that apply
to special mineral processing wastes management occur. The scope of this analysis is limited to the cost and
economic impacts that would be associated with placing the wastes into three potential regulatory scenarios,
focusing on the consequences of regulating these materials as hazardous wastes under Subtitle C of RCRA
EPA has attempted to predict how facility operators would react to having their wastes brought under the
purview of different solid/hazardous waste management regulatory regimes, and has estimated the costs and
impacts of the available waste management options under each regulatory scenario. EPA's approach in
performing this analysis was to delineate all of the applicable requirements comprising each regulatory
scenario, then develop plausible waste management sequences, or "trains", for each of the potentially affected
13 Collins, RJ. and R.H. Miller. 1976. Availability of Mining Wastes and Their Potential for Use as Highway Matenal - Vol 1:
Classification and Technical Environmental Analysis. FHWA-RD-76-106, prepared for the Federal Highway Administration, May. p. 167
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2-24 Chapter 2: Methods and Information Sources
special mineral processing wastes. Plausible management practices or trains are affected by the physical and
chemical characteristics of the wastes in question, and by waste generation rates (all of which are, by definition,
large), as well as by specific federal statutory and regulatory solid and hazardous waste management
requirements. The ways in which prospective regulatory requirements translate into the "on the ground" waste
management strategies that would be employed by affected facility operators are described in Appendix E-3
to this document.
In conducting its analysis of economic impact, EPA has utilized data on the recent performance of
the individual industry sectors and the publicly-held corporations within them to characterize the financial
condition of each potentially affected commodity sector. The incremental costs associated with alternative
regulatory options are compared to several financial indicators in order to determine the relative magnitude
of potential impacts. In addition, the Agency has conducted a qualitative analysis of market conditions facing
each affected facility and sector, and has predicted the extent to which facilities potentially experiencing
compliance costs would be able to pass through these costs to various input and product markets.
This section is organized into three major sub-sections in addition to this introduction. The first
describes the four regulatory scenarios that have been developed for use in the cost analysis; the Agency
believes that these scenarios span the range of the possible regulatory regimes that may be faced by mineral
processors. The second sub-section provides a brief discussion of the costing assumptions and cost equations
that have been used to conduct the analysis, and the third and final sub-section describes EPAs methodology
for evaluating the economic impacts associated with changes in waste management costs.
Development and Application of Regulatory Scenarios
The waste management practices discussed in this report reflect the range of practices that are
currently employed to manage special mineral processing wastes, as well as alternative management techniques
that the Agency believes would be employed by facility operators in response to new regulatory requirements.
They do not represent the only possible practices available, nor do they necessarily include the practices that
would be explicitly required in the event of a change in regulatory st as. Costs are estimated for four
regulatory scenarios: (1) current management practices with no additional action required ("baseline"); (2)
management practices required under full Subtitle C regulation ("Subtitle C"); (3) a less stringent set of
management practices that could be implemented under Subtitle C regulation, allowing for the regulatory
flexibility provided by RCRA §3004(x) ("Subtitle C-minus"); and (4) a scenario developed by EPA for this
report that would address mineral production wastes under the auspices of RCRA Subtitle D
("Subtitle D-Plus").
Two of the alternatives to the baseline are based on Subtitle C of RCRA, and are immediately
germane to the key regulatory decisions that EPA will make based upon this document and additional public
comment (i.e., whether Subtitle C regulation of the 20 special wastes is or is not appropriate). Cost impacts
of full Subtitle C regulation can be calculated with a relatively high degree of confidence because the waste
management alternatives available under Subtitle C are well defined and have been extensively studied, at least
for some industries. EPA has analyzed the Subtitle C-minus scenario because provisions of Section 3004(x)
of RCRA, as added in the 1984 HSWA amendments to the Act, allow flexible Subtitle C regulation for
hazardous wastes generated by the mining and mineral processing industries, as well as certain other special
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Chapter 2: Methods and Information Sources 2-21
Exhibit 2-4
Summary of Results of Selection Criteria Evaluation
Sector
Alumina
Chromate
Coal Gasification
Copper
Elemental Phosphorus
Ferrous Metals
Hydrofluoric Acid
Lead
Magnesium
Phosphoric Acid
Titanium
Zinc
Total
Number of
Facilities
5
2
1
10
5
28
3
5
1
21
9
1
Number of
Facilities in
Study State*
4
2
1
9
5
19
3
4
1
20
5
1
Percent of
Facilities In
Study States
80
100
100
90
100
68
100
80
100
95
56
100
Percent Waste
Volume Generated
In Study States
93
NA(b)
100
90
NA
100
100
NAW
100
Notes on Volume
Data"1
2 of 2 facilities CBI
3 of 10 facilities CBI
3 of 5 facilities CBI
2 of 28 facilities CBI
1 facility NR(cl
3 of 5 facilities CBI
2 of 21 facilities CBI
8 of 9 facilities CBI
(a) CBI = Confidential Business Information
(b) NA = Insufficient data to calculate accurately due to Confidential Business Information (CBI) status
(c) A single hydrofluoric acid facility owned by Dupont did not submit a survey sponse
While this more detailed study partially resolved the regulator, status of special mineral processing
wastes, EPA found that the scope of state programs was not always clear from the state statutory and
regulatory language that was reviewed. The final step of EPA's analysis, therefore, consisted of contacting
state officials involved with the implementation of legal requirements in order to learn how those statutes and
regulations are interpreted in practice, and to obtain facility-specific implementation information. The
information compiled from these contacts was combined with the existing information on statutory and
regulatory requirements to produce a final implementation analysis, which gives the clearest representation
of the existing regulatory structure applicable to the 20 mineral processing wastes generated by the twelve
commodity sectors considered in this Report to Congress.
The findings of this analysis have been included in the sector-specific chapters that follow. For each
of the 18 states containing a facility within a given sector, EPA has provided a description of the regulatory
controls that apply to the management of special mineral processing wastes. A copy of the complete analysis
can be found in Appendix D-2 to this report.
2.2.4 Waste Management Alternatives and Potential Utilization
Section 8002(p) of the RCRA statute requires that EPA consider alternatives to current disposal
methods, as well as the current and potential utilization of the wastes addressed by the Report to Congress.
In order to accomplish this, this report identifies demonstrated alternatives for waste management and
utilization. The costs, current use, potential use, and environmental impact of each alternative are evaluated
to the extent permitted by the information available.
Because the primary purpose of this report is to support a decision as to whether the mineral
processing special wastes are to be regulated as hazardous wastes, EPA has focused its efforts and the
discussion of waste management alternatives presented herein on those wastes that the Agency considers to
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2-22 Chapter 2: Methods and Information Sources
Exhibit 2-6
attribution of States Selected For Further Statutory and Regulatory Analysis
tor the Mineral Processing Wastes Report to Congress
m Which On* or Mow RTC
i ProoMtlng FaeMw are toceted-
Not Selected tor Further Study
(11
i In \WNch One or More FTC Mhwal
StattAoryandRepjlatoryArialyeto (1S8Mes)
' The number In each state Indtoetee the number of RTC rraierel procesekiQ tacUUes tooelad InttM
be candidates for Subtitle C regulation. V&stes that exhibit no intrinsic hazard and pose no significant threat
to human health or the environment under any realistic management scenario are not candidates for Subtitle C
regulation. Therefore, extensive analysis and discussion of the ways in which facilities that generate such
wastes might react to hazardous waste regulation is, in the Agency's view, unnecessary, because the question
is moot. EPA has, nonetheless, provided (at a minimum) short discussions for each of the 20 special wastes
considered in this report addressing potential waste management/utilization alternatives.
Methods
The first step in evaluating the alternatives for managing and utilizing the special mineral processing
waste streams was to identify and obtain (through the National Technical Information Service and inter-library
loans) any documents containing information on current or alternative waste management practices. Once
documents from various sources were received, they were reviewed, and potentially useful information was
extracted and organized according to the waste management or utilization option(s) to which it pertained.
Alternatives for which there was insufficient information with which to evaluate the alternative are not
discussed in this report, nor does the report consider alternatives that are experimental or unproven (i.e., have
not seen full-scale application).
Information Collection
Computer-assisted literature searches were the primary means of identifying documents with
information on the management and utilization of the special waste streams, though useful bibliographies were
also obtained from government agencies, trade associations, and research institutions. Information contained
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Chapter 2: Methods and Information Sources 2-19
damage. The sites included in this report are those for which the available data indicate that the documented
damages are attributable at least in part to mineral processing waste management.
Second, the extent to which the findings can be used to draw conclusions concerning the relative
performance of waste management practices among states or across industry sectors is limited by variations
in requirements and recordkeeping. Recordkeeping varies significantly among states. A few states have
complete and up-to-date central enforcement or monitoring records on mineral processing waste management
facilities within the state. Where states have such records, information on damages may be readily available.
Thus, states that have environmental monitoring information on mineral processing facilities may appear to
contain more sites where damages have resulted from management of special wastes from mineral processing.
More often, enforcement and monitoring records are incomplete and/or distributed throughout
regional offices within the state. Additionally, because mineral processing special wastes are not regulated
under Subtitle C of RCRA, many states do not specifically regulate solid waste management at mineral
processing facilities. Indeed, some states have passed legislation specifically forbidding the responsible state
regulatory agency to impose regulations on solid waste management at mineral processing facilities that are
more stringent than the federal regulations. As a result, monitoring and, thus, detection of problems at
mineral processing facilities has occurred on a very limited basis, if at all, in some states. Therefore, while
damages similar to those identified in states where mineral processing special waste management activities are
monitored may exist in states that do not have an environmental monitoring or regulatory program for mineral
processing special wastes, these damages could not be identified for this report.
Third, data collection efforts generally were focused on the central office of the appropriate state
agencies. In some instances, information may have been available at a state regional office that was not
available in the central office. Furthermore, researchers' ability to collect data at each office sometimes was
limited by the ability of each state to provide staff time to assist in the research.
Finally, because environmental contamination resulting from waste disposal practices often takes many
years to become evident, documented examples of danger that have resulted from particular waste disposal
practices may reflect conditions that no longer exist. Specifically, process feedstocks, processing operations,
waste characteristics, and/or waste management practices may have ch nged. As a result, damage cases
associated with a waste do not necessarily demonstrate that practices use.; to manage waste that is currently
being generated or regulations are in need of change. On the other hand, failure of a site to exhibit
documented damages at present does not necessarily suggest that waste management has not or will not cause
damage. The Agency believes, however, that information on dangers posed by past waste management
practices is useful in demonstrating the potential for environmental and human health impacts when hazardous
constituents are released.
2.2.3 Existing Federal and State Waste Management Controls
Federal Controls
EPA's objective in this analysis was to identify and evaluate the existing regulatory controls over the
management of special mineral processing wastes that have been promulgated by agencies of the federal
government, focusing on programs and requirements established by EPA. This characterization is necessary
for two reasons. First, some states do not have EPA-approved programs for regulating discharges of
contaminants to surface waters (NPDES) or regulating the management of hazardous wastes under Subtitle C
of RCRA, or approved RCRA Subtitle D state solid waste management plans under 40 CFR Pan 256. In
these cases, federal EPA regulations take precedence. Second, the federal government has not delegated
authority to the states for implementing some environmental protection statutes and regulations; thus, the
federal government is responsible for their implementation.
The initial phase of the analysis examined the relevant statutes and regulations pertaining to
hazardous waste, solid waste, air quality, and water quality as they might apply to the management of the
mineral processing special wastes. The purpose of this review was to provide broad background information
on the regulatory authorities available to the federal government that could affect the management of wastes
generated from the extraction, beneficiation, and processing of ores and minerals.
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2-20 Chapter 2: Methods and Information Sources
The second phase of this analysis was to identify and evaluate any specific regulations, such as
NESHAPs, effluent limitations, emission standards, MCLs, etc., that have been promulgated under authority
of any of the major federal environmental statutes that pertain to any of the 20 special mineral processing
wastes.
The final phase of this analysis involved contacting Regional EPA staff in those states that do not
have federally approved programs for implementation of the major environmental statutes (e.g., RCRA,
CWA), as well as relevant staff within other federal agencies and departments (e.g., Bureau of Land
Management, U.S. Forest Service), and performing a detailed regulatory analysis of the implementation of all
existing federal statutes and regulations that pertain specifically to the management of the 20 special mineral
processing wastes. Summaries of the results of this process have been incorporated into the commodity-
specific chapters that follow. Detailed findings of EPA's analysis can be found in Appendix D-l to this report.
Requirements in Selected States
EPA's goal in this analysis was to determine the current regulatory stance of states with regard to the
mineral processing wastes generated by the 12 commodity sectors addressed in this report. The analysis serves
more generally to help characterize current waste management and disposal practices taking place as a result
of state regulation. This characterization is also, to a limited extent, used to establish a baseline for the
analysis of costs and other impacts resulting from current and prospective regulatory requirements.
The first step in the analysis focused on reviewing material in a report on state-level regulation of
mining and mineral processing wastes ("CDM report").12 EPA examined the material in the CDM report
that pertains to all 29 states containing one or more facilities considered in this report, and summarized
portions of the hazardous waste, solid waste, air quality, and water quality statutes and regulations that are
relevant to the current disposition of the special study wastes. Although the CDM report provides a general
overview of state statutory and regulatory requirements addressing wastes from the extraction, beneficiation,
and processing of ores and minerals in all 50 states, it was not designed to provide the detailed analysis of the
scope, and in particular, the implementation of regulations that address ineral processing wastes, that EPA
believes is necessary for this Report to Congress.
The second step of EPA's analysis, therefore, was to perform more detailed review of individual state
statutes and regulations. Time and resource constraints made it impossible to perform a detailed regulatory
analysis on all of the states that contain facilities that generate special mineral processing wastes.
Consequently, this step in the analysis involved selecting a representative sample of the 29 states for further
analysis. The goal of this selection process was to balance the need for comprehensive coverage of the mineral
commodity sectors under study in this report with the need to work with a manageable number of states.
To ensure that the selected states provided comprehensive coverage of the sources of the mineral
processing wastes in question, EPA employed the following criteria: (1) the percentage of facilities in each
state and in each sector covered by the regulatory analysis; and (2) the percentage of total waste volume in
each waste stream and sector covered by the regulatory analysis. Exhibit 2-4 displays the results of the
evaluation of these criteria, which led to the selection of 18 of the 29 states for more detailed regulatory
analysis. In selecting the 18 states, EPA was able to cover at least two-thirds of the facilities in all but one
of the sectors (titanium tetrachloride) and at least 80 percent of the waste volume generated in each sector.
Because a number of firms designated information as business confidential, EPA cannot publish all of the
waste volume percentages; the Agency did, however, examine all of the waste volume data, including data from
facilities that designated their waste generation rates as confidential, to ensure that the 18 studied states
adequately represent the entire population of concern. The geographic distribution of the 18 selected states
is displayed in Exhibit 2-5. The result of this step in the analysis was a summary, organized in a sector-by-
sector format, that contains detailed information on the relevant statutes and regulations from the 18 selected
states, along with shorter summaries addressing the eleven remaining states.
12 Camp. Dresser, and McKee Federal Programs Corporation (CDM). 1989. State Regulation of Solid Wastes from the Extraction.
Beneficiation. and Processing of Non-Fuel Ores and Minerals. June 2.1989. Prepared for U.S. Environmental Protection Agency, Office
of Solid Waste; Document Control Number T1M2-ROO-DR-DELC-1.
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Chapter 2: Methods and Information Sources 2-17
first put into operation, and then to progressively increase in order to simulate gradual deterioration of the
liners/controls after the units are closed. Otherwise, releases to the environment were assumed to occur at
a constant rate because the readily available input data on environmental setting (e.g., annual precipitation,
stream flow, annual average wind speed) are reported as steady-state parameters. The Agency considered a
200-year modeling period because previous EPA risk modeling studies have indicated that this length of time
is adequate to determine whether model results will indicate potential risk, i.e., extending the modeling period
is unlikely to influence the results of the risk modeling exercise.
Documented Cases of Danger to Human Health or the Environment
Section 8002(p)(4) of RCRA requires that EPA's study of mineral processing wastes examine
"documented cases in which danger to human health or the environment has been proved." In order to address
this requirement, EPA defined danger to human health and the environment in the following way. First,
danger to human health includes both acute and chronic effects (e.g., exceedances of drinking water standards,
directly observed health effects such as elevated blood lead levels or loss of life) associated with management
of mineral processing wastes. Second, danger to the environment includes: (1) impairment of natural resources
(e.g., contamination of any current or potential source of drinking water); (2) ecological effects resulting in
impairment of the structure or function of natural ecosystems and habitats; and (3) effects on wildlife resulting
in impairment to terrestrial or aquatic fauna (e.g., reduction in species' diversity or density, impairment of
reproduction).
This section describes the approach the Agency used to address the §8002(p)(4) requirement,
including the "test of proof used and the methods used to identify potential cases, collect documentation, and
verify the accuracy and completeness of the resulting case studies. In addition, this section provides a
discussion of the limitations associated with interpretation of the results obtained. Throughout the discussion,
cases where danger has been proved are often referred to as damage cases.
•Test of Proof
The statutory requirement is that EPA examine proved cases f danger to human health or the
environment. As a result, EPA developed a "test of proof to be used for determining if documentation
available on a case proves that danger/damage has occurred. This "test of proof contains three separate tests;
a case that satisfies one or more of these tests is considered "proved." The tests are as follows:
1. Scientific investigation: Damages are found to exist as part of the findings of a
scientific study. Such studies include both extensive formal investigations supporting
litigation or a State enforcement action and the results of technical tests (such as
monitoring of wells). Scientific studies must demonstrate that damages are significant
in terms of impacts on human health or the environment. For example, information
on contamination of a drinking water aquifer must indicate that contamination levels
exceed drinking water standards.
2. Administrative ruling: Damages are found to exist through a formal administrative
ruling, such as the conclusions of a site report by a field inspector, or through
existence of an enforcement action that cited specific health or environmental
damages.
3. Court decision: Damages are found to exist through the ruling of a court or through
an out-of-coun settlement.
Identification of Potential Damage Cases
EPA identified potential damage case sites by compiling a list of: (1) currently operating mineral
processing facilities based on industry and government sources (e.g., Bureau of Mines); (2) mineral processing
facilities on the National Priorities List under CERCLA; (3) and facilities identified in public comments on
the rulemakings that established the wastes to be studied in this report. Additional facilities were added to
-------
2-18 Chapter 2: Methods and Information Sources
this list during the information collection process described below when state or federal contacts indicated that
additional facilities-should be considered.
Information Collection
EPA used direct telephone and written contacts with state and federal agencies and individuals, as
well as follow-ups to such contacts, to collect information on damage cases. Contacts were made with agencies
in all of the states with one or more of the facilities on the list of potential damage cases (developed as
described above). Specific sources of information included:10
• Relevant state or local agencies, including state environmental regulatory agencies,
mineral or mining regulatory agencies, state, regional, or local departments of health,
and other agencies potentially knowledgeable about damages related to mineral
processing operations;
• Professional or trade associations; and
• Public interest or citizen's groups.
The Agency then visited some of the states contacted to collect information about specific sites from
state files. Selection of states to be visited was based on: (1) the type and complexity of site-specific
information available in state files (based on the contacts with state personnel); (2) EPAs ability to obtain
data of interest from state personnel without visiting the state; (3) the number and type of mineral processing
facilities contained within the state; and (4) environmental factors unique to the state such as climate, geology,
hydrology, and surface water features. Where feasible, information was collected by mail from state personnel.
During visits to state agencies, which were made during the period from November 1988 to February
1990, EPA reviewed documentation on sites on the list of potential damage cases, and collected documentation
on those sites that appeared to meet one or more of the "tests of proof. Follow-up contacts were also made
with agencies, groups, and individuals that the state files or personnel indicated might have additional relevant
information. In addition, EPA also visited some of the mineral process!- facilities in conjunction with visits
to state agencies.
Damage Case Preparation and Review
Following completion of the data collection efforts, EPA prepared summaries of the information
obtained for documented damage case sites. EPA then requested comments on the drafts of these summaries
from the state and federal agency personnel who assisted in providing the information upon which the
summaries were based. EPA specifically requested that the reviewers verify any interpretations of the available
data and identify any available and relevant data that were not included. The comments that EPA received
were used to prepare the final summaries,11 which in turn provide the basis for the discussions of damage
case findings that are included for each type of mineral processing waste covered by this report.
Limitation* of the Damage Cases
The damage case findings that resulted from the process described above must be interpreted with
care, for several reasons. First, mineral processing facilities are often co-located with mineral extraction and
beneficiation (i.e., mining) operations; the mineral processing wastes covered by this report often are or have
been co-managed with other wastes. As a result, it is sometimes difficult to determine if the documented
damages were caused by stack emissions, direct discharges to surface water, etc, rather than mismanagement
of mineral processing special wastes, or if waste management practices have been shown to have caused the
observed damage, which type(s) of wastes (e.g., extraction or processing wastes) caused or contributed to the
10 Although many of the above sources were contacted in developing certain damage cases, the damage case gathering effort relied
principally on information available through EPA regional offices and state and local regulatory agencies.
11 Detailed information on the case study findings is provided in the public docket supporting this report.
-------
Chapter 2: Methods and Information Sources 2-15
facilities. In particular, EPA assessed facility-specific information on a number of factors that relate to the
potential for the waste to be released into ground water, surface water, and air, and subsequently transported
to locations where humans or aquatic organisms could be exposed.
The Agency assessed ground-water release, transport, and exposure potential by evaluating the waste
teachability, management unit characteristics (e.g., presence of engineered controls), hydrogeological setting
characteristics (e.g., net recharge, depth to aquifer, nature of subsurface material), and distance to potential
exposure points. "To assess surface water release, transport, and exposure potential, EPA considered the
distance to the nearest downhill surface water, the likelihood of overland releases of waste from the unit in
stormwater run-off, the likelihood that contaminated ground water could discharge to surface waters, the type
and size of the nearby surface water, and the distance to potential exposure points. Similarly, air pathway
release, transport, and exposure potential was assessed by evaluating the characteristics of the management
unit related to the potential for wind erosion and suspension of dust from vehicular disturbances,
meteorological conditions, and the proximity of the unit to potential exposure points. When possible, EPA
used information developed from the damage case analyses to support the assessments of release, transport,
and exposure potential for all three pathways. For the phosphoric acid and elemental phosphorus sectors,
EPA also relied upon previous Agency analyses7'8 of radiation risks to supplement the data collected
specifically for the present assessment of risk. Based on the findings of this effort, EPA developed qualitative
conclusions on the potential for the wastes to cause impacts by each of these release and exposure pathways.
The scope of this portion of the analysis was limited in several important ways. EPA evaluated only
the baseline hazards of the wastes as they were generated and managed in 1988 at the 91 facilities of interest.
Moreover, the Agency did not assess: (1) risks of off-site use or disposal of the few wastes that are ever
managed off-site; (2) risks associated with potential future changes in waste management practices or
population patterns; or (3) risks of alternative management practices. EPA is unable to extend its assessment
of risk along any of these three dimensions because of insufficient data. However, EPA does evaluate the
hazards of off-site use or disposal in the context of certain damage cases, as well as the hazards of alternative
management practices in the waste-specific discussions of management alternatives and potential utilization.
Risk Modeling
EPA's risk assessment methodology has been designed to develop and present the key determinants
of risk in a form that is objective and readily accessible to interested parties. Risk is a function of (1) the
physical and chemical characteristics of a particular waste (panicle size, constituent concentrations), (2) the
manner in which the waste is managed, and (3) site-specific environmental conditions (e.g., net recharge) and
proximity to potential receptors (e.g., surface water, drinking water wells, wetlands).
Only if the evaluation of these three factors in combination indicates that chemical/radiological
contaminants could reach potential receptors in potentially harmful concentrations is there a need to quantify
the magnitude of any such exposures and their associated risks. Risk modeling is a valuable analytical tool
that the Agency has employed on an as-needed basis to resolve the issue of potential risk in cases where the
result of evaluating the three factors is either ambiguous or indicates a potentially serious risk that requires
more detailed study.
In addition, results obtained by assessing risk-related factors are compared with the findings of the
damage case collection effort that is described below, as a final "reality check.' The data that EPA has
collected to conduct the risk assessment exercise is incomplete in some cases (waste constituent data) and of
limited precision in others (e.g., aquifer characteristics). Consequently, review of damage case information
provides a valuable means of filling information gaps and developing a more complete view of potential risk.
At the same time, however, documented damages associated with management of a given waste do not
necessarily prove that chronic human health or environmental risk is significant. In some instances, for
example, damages may have occurred at sites that are no longer active (i.e., may have different environmental
7 U.S. EPA. 1989, Risk Assessments: Environmental Impact Statement for NESHAPS: Radionuclides. Volume 2 (Background
Information Document). Office of Radiation Programs, September 1989.
8 U.S. EPA, 1990, Idaho Radionuclide Study. Office of Research and Development, Las Vegas Facility, Las Vegas, NV, Apnl 1990.
-------
2-16 Chapter 2: Methods and Information Sources
settings), or may reflect the effects of unusual circumstances (e.g., severe storms). Accordingly, EPA's
evaluation of damage case information in the context of establishing the need for risk modeling accounts for
whether the documented damages reflect actual site conditions and whether the types of observed impacts can
be quantified by the risk model.
If, at the end of this multi-stage process, EPA finds no significant risk potential and no documented
cases of environmental damage associated with a particular special waste, then the Agency believes that (1)
the relevant RCRA §8002(p) study factors have been addressed adequately, and (2) further analysis in the form
of risk modeling would not influence the results of the Agency's analysis or EPAs conclusions regarding the
adequacy of current waste management controls.
Otherwise, EPA conducted further analysis of risk using more sophisticated quantitative methods.
The Agency identified the wastes, facilities, and potential release/exposure pathways that appear to pose
relatively high risks, then used a computer model to quantitatively estimate risks for those wastes, facilities,
and pathways with the highest risk potential. EPA estimated risks on a facility-specific basis using the data
and information sources outlined above.
EPA used the model "Multimedia Soils" (MMSOILS) to estimate the risks posed by mineral
processing wastes. MMSOILS was originally dt.eloped for EPA's Office of Health and Environmental
Assessment9 to estimate the human exposure and health risk associated with contaminated soils at hazardous
waste sites. The model has undergone extensive peer review by several offices of EPA and members of the
academic community. For the purpose of this study, OSW revised MMSOILS to include algorithms for
predicting contaminant releases from various waste management units, such as waste piles, landfills, and
surface impoundments. Appendix C-2 of this report provides a more detailed summary of MMSOILS and how
it was applied in this analysis.
The Agency used MMSOILS to estimate the following risk measures:
• Cancer and chronic non-cancer risks for maximally exposed individuals via the
inhalation and water ingestion pathways, assuming an individual breathed contaminated
air or ingested contaminated water over an entire lifetir e (assumed to be 70 years).
The cancer risk estimates represent the estimated incremer.tal probability of occurrence
of cancer in an exposed individual, over that individual's lifetime. The measure used for
non-cancer risk was the ratio of the maximum estimated chemical dose to the dose of
the chemical at which health effects begin to occur.
• Risks to aquatic organisms caused by chronic exposures to surface water contamination.
The risk measure used for aquatic ecological risk was the ratio of the maximum
estimated surface water concentration of a chemical to the chronic AWQC for that
chemical.
• Potential contamination of air and water in excess of resource damage criteria. The
measure developed for potential air quality degradation was the ratio of maximum
estimated concentrations of airborne lead to the NAAQS for lead. The measures
developed for potential water quality degradation were the ratios of contaminant
concentrations at various downgradient/downstream distances to non-health related
benchmarks.
Ib estimate each of these risk measures, EPA modeled the wastes using median constituent
concentrations, including median concentrations in waste leachate as measured using the EP leach test As
discussed above, EPA believes that use of the EP leachate data is a reasonably conservative approach. The
Agency believes it was appropriate to use median concentrations because the values used for all of the other
model variables (including waste volume, management practice, and environmental setting parameters) were
also typical or central values generally designed to yield "best estimates" of risk.
Finally, EPA considered only chronic, steady-state releases and a 200-year modeling period. Releases
from units with liners or other engineered controls were assumed to begin several years after the units were
9 ICF Technology, Inc. 1988. Methodology for Estimating Multimedia Exposures to Soil Contamination (Draft). Prepared for U.S.
EPA Exposure Assessment Group, Office of Health and Environmental Assessment, Office of Research and Development, December 28.
-------
Chapter 2: Methods and Information Sources 2-13
of the settings in which they are currently managed. The factors of 10 and 100 for ground water and surface
water, respectively^ reflect a minimal level of dilution expected to occur as constituents are released to
receiving waters in which exposures or resource damage could occur. Consequently, the resulting screening
criteria eliminate from further evaluation only those constituents that are not expected to pose a risk, even
in the event that waste contaminant concentrations are not extensively diluted before reaching exposure points
• Human Health/Water Ingestion Screening Criteria. To develop these criteria, EPA used
oral cancer slope factors from IRIS to derive a liquid concentration of carcinogens that
corresponds to a cancer risk of 1 x 10"5. Similarly, the Agency used oral reference doses
from IRIS for non-carcinogens to derive a liquid concentration that, if ingested, would
result in the reference dose. The Agency then multiplied these concentrations by a
factor of 10 to derive a liquid waste or leachate concentration that accounts for possible
dilution that may occur if the waste is released to ground water.
• Aquatic Ecological Risk Screening Criteria. To develop these screening criteria, EPA
compiled available Ambient Water Quality Criteria (AWQC) for both chronic and acute
exposures of both freshwater and saltwater organisms. The Agency selected the lowest
available AWQC for a given constituent and multiplied it by a factor of 100 to derive
a liquid waste or leachate concentration that accounts for possible dilution that may
occur if the waste is released to surface water.
• Water Resource Damage Screening Criteria. To derive these criteria, EPA assembled
the following benchmarks for each constituent detected in the mineral processing waste
samples: primary and secondary Maximum Contaminant Levels (MCLs) for drinking
water; taste and odor thresholds; National Academy of Science (NAS) recommendations
for livestock watering and irrigation; and the AWQC for fish ingestion. Whenever an
MCL was available, EPA used that value multiplied by a factor of 10 to derive a liquid
waste or leachate concentration that accounts for possible dilution that may occur if the
waste is released to ground water. When an MCL was not available, EPA selected the
next lowest value and multiplied that value by either a factor of 10 or a factor of 100
to derive a liquid waste or leachate concentration that ace unts for possible dilution if
the waste is released to ground water (factor of 10) or si :ace water (factor of 100).
EPA pooled all the available data for a given waste stream and compared measured constituent
concentrations in solid and liquid samples to the relevant screening criteria. For this evaluation, the Agency
considered only concentrations that were detected. Analyses for which a given constituent was not detected
were not used to evaluate the hazard posed by the constituent. If a constituent concentration in any sample
of a waste from any facility exceeded one of the screening criteria, regardless of the magnitude of the
exceedance or the frequency of exceedances for the data as a whole, that constituent was considered a potential
constituent of concern for the waste (for purposes of this conservative screening analysis).
The data used in the risk assessment include leachate concentrations from a number of leach tests,
including the Extraction Procedure (EP), the Tbxicity Characteristic Leaching Procedure (TCLP), and the
Synthetic Precipitation Leaching Procedure (SPLP).4 Because most of the available data are from EP leach
tests, the Agency relied most heavily on these data in evaluating potential constituents of concern in
leachate.5 The Agency recognizes that the EP leachate test is a relatively conservative approach for
estimating the concentrations of some metals in leachate generated from the mineral processing wastes as they
are currently managed. To determine the extent to which EP leachate data differ from SPLP leachate data,
the Agency evaluated the differences between SPLP and EP leachate concentrations for the special wastes.
This evaluation demonstrated that although the two tests provide similar results for many constituents in most
wastes, some constituents (e.g., iron, lead, zinc, aluminum, cadmium, copper, nickel) are commonly present
in higher concentrations in EP leachate than in SPLP leachate. A smaller number of constituents (e.g.,
4 EPA Methods 1310,1311, and 1312, respectively.
5 The recently promulgated (March 29, 1990) Toricity Characteristic (TC) will replace the EP Tojncity characteristic as of its effective
date. Because, however, the wastes considered in this report are, for the most pan, unlikely to contain the organic constituents that were
added by the TC, and because the regulatory levels for metals employed in these two methods are identical, the Agency believes that any
conclusions regarding the inherent toncity of the wastes considered in this report are likely to remain valid once the TC becomes effective.
-------
2-14 Chapter 2: Methods and Information Sources
arsenic, vanadium, molybdenum, barium) are commonly found in higher concentrations in SPLP leachate than
EP leachate. Given the conservative nature of this screen and the preponderance of EP leachate data, the
Agency believes that it is appropriate to use EP leachate data in this evaluation of mineral processing wastes.
EPA acknowledges that this use of the EP leachate data differs from the approach used in the
Agency's recent nilemakings on mineral processing wastes (reinterpreting the scope of the Mining Waste
Exclusion), but believes that there are sound reasons for adopting this approach. In the rulemakings, EPA
collected and used limited SPLP data in order to establish which wastes qualify as "low hazard" and are thus
eligible for detailed study in this report (i.e., use of the SPLP data was a reasonable approach for selecting the
wastes to be studied, because wastes that exhibit hazardous characteristics under the SPLP test are clearly not
low hazard). For purposes of actually conducting a risk assessment, however, relying primarily on the EP
leachate data is a reasonable, though more conservative (i.e., protective) approach.
Evaluation of Constituent Persistence and Mobility. Even though a constituent may exist in a
waste in potentially harmful concentrations, the constituent may pose little or no risk if it rapidly degrades
in the environment or if it is unable to migrate away from the waste management unit. Therefore, for each
potential constituent of concern identified based on its concentration relative to screening criteria, EPA
evaluated the extent to which the constituent can persist and migrate in the environment.
Because most of the constituents that are present in mineral processing wastes in elevated
concentrations are metals that do not degrade in the environment, the evaluation of persistence was largely
a moot exercise. However, for the organic constituents detected in elevated concentrations in a few of the
wastes, EPA evaluated the constituents' persistence by considering their degradation rates in ground water,
surface water, and air.
To evaluate constituent mobility, the Agency considered the tendency for each constituent to bind
to soil when present in ground water and the potential for organic constituents to be released to the air by
volatilization. For the analysis of ground-water mobility, EPA examined the sorption coefficient (Kd, a
measure of the degree to which contaminants bind to soil) for each incr anic constituent and assumed that
inorganic constituents with Kj values less than 20 ml/g are relatively mob e in ground water, while inorganics
with Kj values greater than 20 ml/g are relatively immobile in ground water. This assumption is based on the
results of previous modeling exercises that demonstrated that constituents with Kj's greater than 20 ml/g often
migrate so slowly in ground water that they do not reach distances of interest within 200 years (i.e., their
potential to endanger human health and damage water quality over typical modeling horizons is extremely
limited).6 For organics that were detected, EPA evaluated each constituent's Henry's Law constant, a
parameter that indicates the degree to which a constituent is likely to be released to air by volatilization from
aqueous solution.
Conclusions from Intrinsic Hazard Evaluation. Given the conservative (i.e., protective) nature
of the screening criteria, waste constituents that are present in concentrations below the screening criteria are
not likely to pose a risk to human health or the environment. On the other hand, exceedances of the
screening criteria should not, in isolation, be interpreted as proof of hazard. Therefore, if a constituent in any
sample of a waste exceeded a screening criterion, and if the constituent was considered persistent and mobile
in the environment, EPA concluded that risk posed by the waste should be evaluated further. EPA then
proceeded to the next step of the risk assessment to evaluate the potential for constituents of concern to be
released into the environment and migrate to receptor locations, by considering the existing waste management
practices and environmental settings of the facilities that generate the waste.
Evaluation of Release, Transport, and Exposure Potential
In this second step of the risk assessment, the Agency evaluated the potential for the waste to pose
risks to human health and the environment based on its current management at the 91 mineral processing
6 U.S. EPA. 1987. Onshore Oil and Gas Exploration. Development, and Production: Human Health and Environmental Risk
Assessment (Technical Support Document). Office of Solid Waste, December.
-------
Chapter 2: Methods and Information Sources 2-11
Exhibit 2-2
Overview of Constituents of Concern Screening Criteria
Sample Test Type
Type of Hazard
Thai is Evaluated
Assumed Release/
Exposure Pathway
That Underlies
Screening Criteria
Screening Criteria
Solid Samples
Human Health Risk
Air Quality Degradation
Inhalation of airborne
participates
Incidental ingestion
of waste and con-
taminated soil
Radiation exposure
to contaminated land
Airborne release of
lead as windblown
dust
Inhalation toxicity criteria for cancer and non-
cancer effects, assuming that dust is blown into
the air in a concentration that equals the National
Ambient Air Quality Standard (NAAQS) for par-
ticulate matter
Oral toxicity criteria for cancer and noncancer
effects, assuming that access to a waste is not re-
stricted and children incidentally ingest con-
taminated solids
EPA's radium-226 cleanup standard for uranium
mill tailings sites; Nuclear Regulatory Commission
guidelines on uranium-238 and thonum-232 con-
centrations in soil that can be released for un-
restricted use
Lead concentration in waste that could result in
an exceedance of the NAAQS for lead if dust is
blown into the air in a concentration that equals
that NAAQS for particulate matter
Liquid Samples
(including leachate
test samples)
Human Hearth Risk
Aquatic Ecological Risk
Surface and Ground-
Water Quality Degra-
dation
Ingestion of con-
taminated ground
water
Release of waste
constituents to sur-
face water and ex-
posure of aquatic
organisms
Release of waste
constituents to sur-
face or ground water
10 times oral toxicity criteria for cancer and
noncanc effects, assuming ingestion of 2 liters
of coma nated water per day for 70 years
100 times Ambient Water Quality Criteria (AWQC)
10 times drinking water maximum contaminant
levels when available; otherwise, the lower of: (1)
10 times the taste and odor thresholds, livestock
watering guidelines, or irrigation guidelines; or (2)
100 times the AWQC for fish ingestion
guidelines, the radiation criteria are based on the assumption that public access to the
waste is unrestricted.
• Air Resource Damage Screening Criterion. To screen for the potential for mineral
processing waste solids to degrade ambient air quality, EPA used the NAAQS for
paniculate matter and the NAAQS for lead to derive a lead concentration in solid waste
(there are no NAAQSs for any other metals that could exist in mineral processing
wastes). Exceedance of this screening criterion indicates the potential for an exceedance
of the lead standard if a sufficient amount of a waste is blown into the air as dust.
The screening criteria used to evaluate constituent concentrations in liquid samples (either total liquid
or leach test analyses) include criteria that reflect the potential for hazards to human health via water
ingestion, adverse effects to aquatic organisms, and degradation of surface and ground-water quality. In
developing these criteria, the Agency has assumed a 10-fold dilution of liquid wastes or leachate into ground
water and a 100-fold dilution in surface water. The Agency selected these conservative (i.e., small) dilution
factors because the screening criteria are designed to evaluate the intrinsic hazard of the wastes, irrespective
-------
2-12 Chapter 2: Methods and Information Sources
Exhibit 2-3
Screening Criteria Values(a)
Constituent
Acetonitnle
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Chloride
Chromium(VI)
Cobalt
Copper
Fluoride
Gross alpha
Gross beta
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Nitrate
Nitrite
PH
Phenol
Phosphorus
Phosphate (Total)
Radium-226
Selenium
Silver
Sulfate
Suspended Solids
Thallium
Thorium-232
Uranium-238
Vanadium
Zinc
Screening Criteria for Solid Sample*
Inhalation
(Mg/g)
-
_»»
-
14
7,000
84
-
115
-
17
-
-
-
-
-
-
30,000™
-
21,000
-
-
833
-
-
-
-
-
-
l34pCi/g
80
-
-
-
-
i3pci/g
17pCi/g
-
-
Incidental
lnge*tlon
(Ag/g)
4,200
-
280
4
35,000
3,500
63,000
350
-
3,500
-
25,900
42.000
-
-
-
420
-
140,000
210
-
14,000
700,000
70,000
-
420,000
-
-
-
2,100
2,100
-
-
49
-
-
4,900
140.000
Radiation
(pCI/g)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
5
-
-
-
-
-
10
10
-
-
Screening Criteria for Liquid/leach Te*t Sample*
Human Hearth
(Ingeetlon)
Oig/t)
2,100
-
140
2
18,000
1,800
32,000
180
-
1,800
-
13,000
21,000
-
-
-
210
-
70.000
100
-
7,000
390,000
35,000
-
210,000
-
-
16pCi/L
1,100
1,100
-
-
25
91 pCVL
15pCi/L
2,500
70,000
Aquatic
Ecological
Oifl/U
-
8,700
160,000
1.300
5,000,000
530
500,000
110
23,000,000
1,100
-
290
-
-
-
100,000
320
_«J)
100.000
1.2
-
830
9,000,000
6,000
6.5-9
256,000
10
2.500
-
500
12
2.500,000
4,000
-
-
128,000
8,600
Water
Resource
Damage Oig/U)
-
50.000
4,500,000
500
10.000
120
7,500
100
2,500,000
500
500
13,000
40,000
1 50 pCi/L
SOOpCVI.
3,000
50
-
500
20
100
2,000
100,000
10,000
6.5-8-5
1
-
-
50pCi/L
100
500
2,500,000
-
4,600
-
-
1,000
50,000
(a) See text for an explanation of the derivation of these screening criteria and Appendix C-1 of this report for a presentation of the
benchmarks upon which these screening criteria are based. Some of these screening criteria, especially the incidental ingestion
criteria, are very high values (e.g., the incidental ingestion criterion for nitrate is more concentrated than normal fertilizer).
However, they were derived using the methods described in the text and represent concentrations that could be harmful under
the assumed exposure scenarios.
(b) No screening criterion used because of lack of applicable benchmarks.
(c) No inhalation RfD for lead is provided in IRIS. This value is the screening criterion used to analyze the potential for 'air quality
degradation.'
(d) An aquatic ecological screening criterion of 5,000,000 ug/L Total Dissolved Solids was used to evaluate the combined
concentration of magnesium and sulfate.
-------
Chapter 2: Methods and Information Sources 2-9
detailed discussion on the amount and nature of data considered for each special waste is provided in the
sector-specific chapters of this report.
Although data on waste composition were provided in responses to the 1989 National Survey of Solid
Wastes from Mineral Processing Facilities, the Agency did not use these data in the risk assessment for two
reasons. First, the survey responses often provide information on only the primary components of the waste
and do not characterize the waste's trace constituents, which are often important from a risk assessment
standpoint. Second, the survey responses provide only single, "typical" concentrations and do not indicate the
number of samples upon which those typical values are based, the time frame over which the samples were
collected, the sampling locations, or the distribution of individual sample results. As a result, the typical
concentrations reported in the survey could not be integrated with sampling data from the other sources
outlined above to develop overall statistics on the frequency and magnitude with which constituent
concentrations exceed the screening cnteria.
Waste Management Practice Data. For data on current waste management practices, EPA relied
primarily on information provided in response to the 1989 National Survey of Solid Wastes from Mineral
Processing Facilities and information collected from visits to a number of the facilities studied for this report.
The survey responses, prepared by facility personnel, include information on the waste volumes generated and
managed at each plant, the quantity of waste managed in individual units, and the design characteristics of each
management unit. Reports from visits to mineral processing facilities for sampling or other information
collection purposes were used to supplement the data provided in the survey responses. These reports contain
additional information on the design of waste management units as well as observations about the physical
form of the wastes and photographs of the waste management units.
Environmental Setting Data. EPA relied on a number of sources of data on the environmental
setting of the 91 facilities that generate the special wastes covered by this study. The environmental setting
data collected for the risk assessment include information on climate gical conditions, factors affecting
atmospheric dispersion, hydrogeological parameters, surface water characu nstics, population distributions, and
proximity to sensitive environments (i.e., environments that are vulnerable or have a high resource value, such
as National Parks or Forests). These data were collected from a number of sources, including EPA data
compilations (e.g., Graphical Exposure Modeling System [GEMS] and Federal Reporting Data System
[FRDS]); responses to the 1989 National Survey of Solid Wastes from Mineral Processing Facilities; U.S.
Geological Survey (USGS) topographic maps and hydrologic data files; the National Water Well Association's
DRASTIC ground-water vulnerability system; soil surveys developed by the Soil Conservation Service of the
U.S. Department of Agriculture, and U.S. Department of the Interior (DOI) maps of the critical habitat of
endangered species (50 CFR 17.95).
Evaluation of Intrinsic Hazard of Wattes
As the first step of its risk assessment, EPA screened the waste composition data described above to
determine if the special wastes contain toxic or radioactive constituents at concentrations that could pose risks
to human health, aquatic organisms, and air and water resource quality. The objective of this screening
procedure was twofold: (1) to narrow the focus of the risk assessment by eliminating from further evaluation
those constituents that are unlikely to endanger human health or the environment; and (2) to identify any
constituents that warrant further evaluation (i.e., constituents of potential concern). To determine constituents
of potential concern, EPA compared the constituent concentrations measured in samples of mineral processing
wastes to screening criteria, and evaluated the persistence and mobility of each constituent in various
environmental media.
Comparison of Chemical Concentrations to Screening Criteria. EPA developed a set of
constituent-specific screening criteria that reflect the potential for hazards to human health, aquatic organisms,
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2-10 Chapter 2: Methods and Information Sources
and air and water quality based on conservative release, transport, and exposure assumptions. These screening
criteria represent constituent concentrations in waste or leachate samples that could endanger human health.
aquatic life, or water or air quality if the waste is released to the environment. Because this step is intended
to evaluate the intrinsic hazard of the wastes, the screening criteria are based on exposure assumptions that
are likely to overstate the risks posed by the management of the wastes at the facilities of concern.
Consequently, this step identifies all constituents that warrant further evaluation as potential constituents of
concern, and only those constituents that do not contribute to the intrinsic hazard of the waste are removed
from further consideration. The underlying rationale for the screening criteria developed for this analysis is
summarized in Exhibit 2-2, and the actual screening values are listed in Exhibit 2-3 (the benchmarks upon
which these screening criteria were developed are provided in Appendix C-l of this report). All screening
criteria developed for chromium assume that this metal is present in its more toxic hexavalent form.
As shown in Exhibits 2-2 and 2-3, the screening criteria can be divided into two main categories: (1)
criteria to compare to constituent concentrations measured in solid samples, and (2) criteria to compare to
constituent concentrations measured in liquid and leachate extract samples, or in extract samples from solids.
The screening criteria compared to concentrations in solid samples include criteria that reflect the potential
for hazards to human health via inhalation, incidental soil ingestion, and multiple radiation exposure pathways,
as well as a criterion that reflects the potential for air quality degradation.
• Human Health/Inhalation Screening Criteria. To develop these criteria, the Agency
used inhalation cancer slope factors from EPAs Integrated Risk Information System
(IRIS) to derive an airborne concentration of carcinogens that corresponds to a lifetime
cancer risk of 1 x 10'5. Similarly, the Agency used inhalation reference doses from IRIS
for non-carcinogens to derive an airborne- concentration that, if inhaled, would result
in the reference dose. Tb convert these airborne concentrations (in units of ug/m3) to
solid concentrations (in units of ug/g) the Agency made two conservative (i.e.,
protective) assumptions: (1) the airborne concentration of respirable particles equals
the National Ambient Air Quality Standard (NAAQS) for -espirable paniculate matter
(50 ug/m3), and (2) the constituent concentration in the arborne respirable panicles
equals the constituent concentration in the waste. These assumptions probably
overestimate the extent to which respirable particles are blown into the air from the
special wastes studied in this report because many of the wastes are in the form of large
particles (ranging in size all the way up to boulders) or form surface crusts that are not
susceptible to dust generation.
• Human Health/Soil Ingestion Screening Criteria. To develop these screening criteria,
EPA used oral cancer slope factors and non-cancer reference doses from IRIS, along
with an Agency guideline on soil ingestion rates,2 to derive a waste concentration that
could cause health risks if small quantities of the waste are incidentally ingested on a
routine basis. These screening criteria are based on the assumption that public access
to the wastes is not restricted and, for example, children are allowed to play on, or in
the vicinity of, special waste management units.
• Human Health/Radiation Exposure Screening Criteria. To screen for potential
radiation hazards, the Agency used EPAs standard in 40 CFR 192 for the clean up of
soil contaminated with radium-226 at uranium mill tailings sites (5 pCi/g). This
standard is designed to limit the risk from the inhalation of radon decay products in
houses built on contaminated land and to limit gamma radiation exposures of people
using contaminated land. The Agency also used the Nuclear Regulatory Commission's
(NRC's) guidelines for acceptable concentrations of uranium-238 and thorium-232 in
soil that can be released for unrestricted use.3 As stated in these standards and
2 Memorandum from J. Winston Porter, Assistant Administrator for EPA's Office of Solid Waste and Emergency Response, to EPA
Regional Administrators, concerning Interim Final Guidance for Soil Ingestion Rates, OSWER Directive 9850.4, January 27, 1989.
3 NRC, 1981. Disposal or Onsite Storage of Residual Thorium or Uranium (Either as Natural Ores or Without Daughters Present)
from Past Operations, SECY 81-576, October 5.
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Chapter 2: Method* and Information Sources 2-7
Exhibit 2-1
Overview of Risk Assessment Methodology
All Wastes and All Facilities
Steal: Evaluate Intrinsic Hazard of Waste
Are there constituents of concern?
No
l
Yes
Evaluate Release, Transport, and Exposure Potential
Do potential exposure pathways exist?
, Yes
Group wastes/facilities into 3 categories:
high, medium, and low hazard potential
l
Model Risks
Model high risk wastes/facilities. Are risks significant?
Model medium risk wastes/facilities. Are risks significant?
Model tow risk wastes/facilities
No
No
No
No
Further
Analysis
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2-8 Chapter 2: Methods and Information Sources
was limited initially to facilities with the highest risk potential. Modeling of additional facilities was performed
only if estimated risks were significant for the facilities with high risk potential.
In all steps of the analysis, EPA focused on human health and environmental risks associated with
chronic exposures to potential releases of waste constituents to ground water, surface water, and air. While
large, short-term (acute) exposures to these wastes may occur, this analysis is restricted to chronic exposures.
for two reasons. First, given the relatively low hazard of these wastes (as documented by application of the
low hazard criterion used in the Agency's recent rulemakings on these special wastes), EPA concluded that
the potential for adverse effects from large, short-term exposures to these wastes is very limited (i.e.. acute risk
generally occurs at levels of exposure that are not likely given the low hazard of these wastes). Second, most
of the lexicological data and exposure assumptions available for the purpose of risk assessment are based on
chronic exposures. When possible, the Agency did evaluate the potential for large episodic releases of waste
constituents (e.g., from storm or flood events) to endanger human health or the environment.
To analyze risks to human health, the Agency evaluated the cancer and non-cancer risks to maximally
exposed individuals at each site. A "maximally exposed individual" is designated for each exposure pathway
as the person at greatest risk from exposures to toxic constituents released into the environment. EPA did
not assess population risks explicitly, but data on potentially exposed populations were considered in drawing
conclusions about the overall risks associated with the current management of special wastes.
To analyze environmental risks, the Agency evaluated the potential for contaminants to migrate from
the waste and adversely affect aquatic organisms. EPA did not attempt to evaluate potential impacts on
terrestrial ecosystems because little information is available on the exposure of terrestrial organisms to waste
constituents and lexicological data relevani 10 lerresirial ecosysiems are limited. In addition to risks 10 human
healih and aquaiic life, EPA also evaluaied ihe poieniial for exisiing waste managemenl practices to cause air
and waier coniaminaiion, irrespeciive of ihe poieniial for humans or ecological recepiors lo be exposed 10 ihe
contamination.
Data Used in the Risk Assessment
To conduct ihe risk assessmenl as ouilined above, EPA collecied and evaluaied daia on ihe faciors
thai influence risks ai each facility ihai generaies ihe wasies. EPA's data collection focused on ihree major
caiegories of informaiion:
• wasie composition daia,
• wasie managemenl practice data, and
• environmental setting data.
Waste Composition Data. The Agency relied on three primary sources for data on the chemical
composition of each mineral processing waste. First, the Agency used data collected by OSW during sampling
visiis in 1989. OSW sampled ihe wastes at a toial of 27 of ihe 91 affected facilities. The Agency sampled at
leasi two facilities for each waste stream unless the waste is generated by only a single facility. Second, the
Agency used data submitted by industry in response 10 an EPA request for data under §3007 of RCRA. A
toial of 64 facilities submitted useable waste composition data in response to this request, and all wastes of
interesi are represented in these data except magnesium process wastewater and treated roast/leach ore residue
from sodium dichromate production. Third, EPA used waste composition data collected by ORD during
sampling visits in 1984 and 1986, and daia collecied by OSW during sampling visits in 1985. Data collected
by ORD are available for five wastes siudied in ihis report: lead slag, copper slag, phosphoric acid process
wastewaier, phosphogypsum, and elemenial phosphorus slag. Daia collecied by OSW in 1985 are for red and
brown muds from alumina produciion. All logeiher, ihese ihree sources provide daia on ihe concentration
of some 20 metals, 3 radionuclides, gross alpha and beia radiaiion, and a number of olher consiiiuenis
(including several ions and, in ihe case of ihe coal gasificaiion wasies, numerous organic compounds). A more
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Chapter 2: Methods and Information Sources 2-5
Waste Generation and Management
In order to describe each facility's waste generation and to prepare the analyses of risk and cost and
economic impacts, and potential for alternative utilization, the Agency needed to accurately assess the volume
of waste generated at each facility. In estimating waste generation rates for the twenty waste streams. EPA
primarily used data from its 1989 National Survey of Solid Wastes from Mineral Processing Facilities (SWMPF
Survey), and information supplied by industry experts at the U.S. Bureau of Mines. In some cases, EPA
utilized data submitted in public comments by facility operators and trade associations.
EPA also compiled and tabulated facility-specific data on the general physical characteristics and
chemical composition of the twenty wastes, and on the practices employed to manage them, again based
primarily on the SWMPF Survey data, and has used these data in subsequent analyses. Such data also came
from EPA sampling activities, site visits, and other data collection requests (e.g., RCRA §3007 requests.
damage case data collection). Facility-specific details regarding waste management include type(s) of
management units and volumes managed in each unit, pollution controls in place for each unit (e.g., liner type
and number, presence of leachate collection systems, run-on/run-off and wind dispersal controls), and whether
or not ground water, surface water, and/or air is currently monitored. EPA also collected and evaluated
information on waste treatment, including types of reagents used and management techniques applied to
treatment sludges and effluent(s).
Information submitted by industry in response to the SWMPF Survey was supplemented and critically
evaluated against data obtained from published sources, information collected as pan of the damage case
development process, and EPA observations made during waste sampling and other site visits. The
descriptions of waste management practices provided in this report reflect EPA's synthesis of the information
obtained during all of these information collection activities.
Relationship of Waste Generation and Management Practice
Information to other Parts of the Report
Waste characteristics, generation, and management data have been collected and analyzed for two
primary purposes: 1) to understand the industry (i.e. RCRA §8002(p)(l-2) require EPA to analyze "the source
and volumes of such materials generated per year; (and) the present disposal and utilization practices"), and
2) to evaluate risk, alternative management practices (including utilization), and costs and impacts of such
alternative management practices (RCRA §8002(p)(3) and (5-6)).
Risk Assessment
Waste generation rates, physical and chemical characteristics, and management practices are three
major inputs to the analysis of the risk posed to human health and the environment by the wastes under study
in this report. The quantity of waste managed is important in evaluating the magnitude and duration of
environmental impacts. Waste characteristics, in part, determine whether the waste has the potential to release
harmful constituents to the environment. Knowledge of waste management practices, including controls (e.g.,
caps, liners) for the protection of the various media of environmental transport (e.g., air, surface water, ground
water) will, in part, determine the ability of any harmful constituents to be transported to potential human
or biotic receptors.
Evaluation of Management Alternatives and Potential Utilization
Waste characteristics and the outcome of the risk and damage case analyses determine the need for
and types of alternative management practices that EPA might consider. In addition, the technical feasibility
of management alternatives and the economic feasibility of utilization alternatives are directly affected by waste
generation rates.
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2-6 Chapter 2: Methods and Information Sources
Cost and Economic Impacts
The volume and management practice data are key inputs into the evaluation of the costs of both
existing and alternative waste management practices. Cost estimation equations are driven primarily by the
volume of the waste managed and include a logarithmic component to simulate the effects of economies of
scale. Alternative waste management practices involve compliance with additional design specifications that
must-be modeled by the cost estimation procedure. Waste characteristics are important in that they are a
factor in determining what type of management alternatives may be required for the protection of human
health and the environment.
2.2.2 Potential and Documented Danger to
Human Health and the Environment
Potential Danger to Human Health and the Environment
EPA conducted a facility-specific analysis of the risks associated with each of the 20 mineral
processing wastes. The Agency collected information on the major factors that influence risks from the
management of the special wastes at each of the 91 facilities that generate the wastes, and analyzed this
information to develop conclusions on the potential for toxic constituents to be released from the waste and
cause human health and environmental impacts.
EPA used a three step approach in this risk assessment, as illustrated in Exhibit 2-1:
• First, the Agency assessed the intrinsic hazard of the wastes by comparing the
concentrations of toxic or radioactive constituents in the wastes and in the leachate
extracts from the wastes to screening criteria.1 This step was used to determine which
constituents of the special wastes do not pose a risk to human health or the environ-
ment, even under very conservative (i.e., protective) relea .* and exposure assumptions.
If a waste contained constituents in concentrations that exceeded the screening criteria,
then the Agency further evaluated (in the next step of the analysis) the potential for the
waste to pose risk. A detailed discussion of the screening criteria and their derivation
is provided later in this chapter and in Appendix C-l to this report.
• Second, EPA assessed the potential for constituents of potential concern from the
wastes to cause damage at the 91 facilities that generate the special wastes by evaluating
the practices currently used to manage the wastes and the environmental settings in
which the wastes are managed. Using facility-specific information about special waste
management and environmental setting, EPA evaluated the potential for toxic or
radioactive constituents that exceed the screening criteria to be released from waste
management units and to migrate to potential exposure points.
• Third, EPA performed quantitative modeling to estimate the human health and
environmental risks associated with existing waste management practices. In this
portion of the analysis, EPA estimated risks for only those wastes, facilities, and
potential release and exposure pathways that appeared to pose a hazard based on the
findings from the previous steps of the risk assessment.
The Agency used each step as a means of narrowing the scope of the analysis to those wastes and
facilities that pose the greatest potential risk. The evaluation of the intrinsic hazards of the wastes (Step 1)
was used to eliminate from further consideration any toxic or radioactive constituents that are not present in
concentrations of concern (based on conservative exposure assumptions). Evaluation of release, transport,
and exposure potential (Step 2) was used to identify potential exposure pathways and to allow a categorization
of the risk potential (i.e., high, medium, low) for all facilities generating each waste. Risk modeling (Step 3)
1 The focus of the screening cntena is on toncity and radioactivity, in addition to a simple determination of corrosivity EPA has
sufficient knowledge of the characteristics of the 20 special mineral processing wastes to conclude that none are ignitable or reactive.
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Chapter 2: Methods and Information Sources 2-3
RCRA §3007 Waste Characteristics Data Request
In order to augment existing EPA waste characterization data and to allow affected facilities to have
meaningful input into the Agency's evaluation of the physical and chemical characteristics of temporanh
exempt mineral processing wastes, EPA issued a formal written request, under authority of RCRA §3007, to
facility operators seeking any currently available .information on the characteristics of the candidate special
mineral processing wastes that they generate. The request did not specify the quantity of data required by
EPA or a data format, so as to make compliance by the facility operators as simple as possible. An example
of the §3007 data request is presented in Appendix B-4 to this report.
Facility operators responded in a number of different ways, up to and including submitting hundreds
of pages of process control data. EPA has reviewed all of these data submittals and has collected and
summarized all data that are both useable (e.g., identity of waste stream and analytical testing method is clear)
and relevant to this study.
2.2 Analytical Approach and Methods
EPA has consolidated its analysis of certain of the eight study factors identified in Chapter 1, so as
to facilitate focused analysis and clear exposition of the information that is germane to the decisions at hand,
i.e., whether Subtitle C regulation of any of the 20 special mineral processing wastes is appropriate. The
Agency has employed this approach because several of the study factors overlap or are closely related to one
another. Consequently, the sector-specific chapters that follow consist of an introduction, five substantive
sections addressing the study factors, and a summary section.
The remainder of this chapter summarizes EPA's approach for addressing each of the required study
factors. The sections that follow present the methods that the Agency has employed in preparing the six
substantive parts of each sector-specific chapter:
• Section 2.2.1. \teste Generation. Characteristics, and Cu rent Manaeement Practices.
describes the identification of facilities that generate one or more of the special study
wastes, development of descriptions of production processes, product uses, general waste
composition, and waste generation and management practices (study factors 1 and 2),
as well as the relationship of this information to analysis of the remaining study factors.
Section 2.2.2. Potential and Documented Danger to Human Health and the Environ-
ment, presents the approach that EPA used to assess the potential danger posed by each
of the 20 wastes under study and identify proven cases of danger to human health and
the environment (study factors 3 and 4).
Section 2.2.3. Existing Federal and State \\frste Manaeement Controls, describes the
Agency's approach to developing an improved understanding of current federal and state
requirements that apply to special mineral processing wastes (as suggested by §8002(p)
of RCRA, independent of the eight study factors).
. Section 2.2.4. Alternative Management Practices and Potential Utilization, discusses the
identification and evaluation of alternatives to current waste management and utilization
practices (study factors 5 and 8).
• Section 2.2.5. Cost and Economic Impacts, presents the Agency's approach to specifying
alternative regulatory scenarios and estimating the associated costs and economic
impacts (study factors 6 and 7).
• Section 2.2.6. Summary, provides a description of the way in which EPA has evaluated
the study factors, in order to facilitate future regulatory decision-making.
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2-4 Chapter 2: Methods and Information Sources
2.2.1 Waste Characteristics, Generation, and
Current Management Practices
To characterize the generation and management of each of the 20 special mineral processing wastes,
EPA needed to identify the facilities that generate the wastes, the production processes used and the products
produced, the quantity and characteristics of the wastes generated, and the practices that are employed to
manage them. EPA!s approach to addressing each of these needs is described below, followed by a discussion
of the relationship of the resulting information to the other study factors.
Affected Facilities
The identification of the facilities that generate one or more of the twenty special wastes was begun
during the reinterpretation of the Mining Waste Exclusion for mineral processing wastes. This rulemaking
process began in August, 1988 and continued through the publication of a final rule in January 1990.
Beginning with previous EPA studies and additional published sources (e.g., SRI International's Directory of
Chemical Producers-United States. 1989 Ed.), and relying extensively on support from Commodity Specialists
with the U.S. Bureau of Mines, the Agency established a list of facilities that were believed to produce a
mineral commodity of interest and potentially generate a special waste. The operators of these facilities were
sent a survey requesting information on waste generation and management. A brief discussion of the survey
is provided above in Section 2.1. Survey responses allowed EPA to finalize its list of the active facilities in
the mineral processing sectors of concern. Production data (e.g., quantity of the primary commodity produced,
the age and capacity of the operation) were also obtained from these surveys.
Process Descriptions and Product Use(s)
Process descriptions were developed to characterize the major typ s) of process operations employed
in each sector. Detailed discussion of waste generation from these processes within this report is limited to
the special waste(s) within each commodity (i.e., one of the twenty waste streams studied in this report) and
does not involve other wastes or secondary materials that may be generated.
Information regarding production processes was taken primarily from the Encyclopedia of Chemical
Technology edited by Marks, et al., and published in 1978. This source, however, provides little or no
information regarding the point-of-generation of the waste streams in question. Relevant point-of-generation
data were obtained from public comments submitted by the industry, previous EPA reports (e.g., Overviews
of Solid Waste Generation, Management, and Chemical Characteristics for various processing sectors prepared
for EPA by PEI Associates and Radian Corporation), and Bureau of Mines publications (e.g., Mineral Facts
and Problems. 1985 Ed.).
Information describing the use of mineral products was taken primarily from Bureau of Mines
publications (i.e., Mineral Facts and Problems. 1985 Ed., Mineral Commodity Summaries. 1989 Ed., and
Minerals Yearbook. 1987 Ed.). Additional information was obtained from public comments and trade
publications.
EPA's understanding of mineral production processes and product uses has also been significantly
enriched as a result of the field sampling and site visits described above. In a number of instances, subtle
differences between facilities in a given commodity sector with respect to the production processes employed
and product types produced (hence, markets served) have been noted. The knowledge gained thereby has been
incorporated into the Agency's analyses and throughout the sector-specific discussions that follow this chapter,
as appropriate.
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Chapter 2
Methods and Information Sources
In preparing this report, EPA has developed facility-specific data and analytical methods that reflect
the complexity of the issues that are addressed herein. The facilities that generate the special study wastes vary
considerably in the types of production operations and waste management techniques that they employ.
Moreover, to examine in detail the broad array of study factors mandated by RCRA §8002(p), EPA had to
develop approaches and methods that were sufficiently sophisticated to take into account the special nature
of high volume mineral processing wastes. This chapter outlines the data sources and methods that the
Agency employed to respond to the statutory study factors, beginning with a discussion of the major data
collection initiatives that EPA's Office of Solid Waste conducted during 1989 and proceeding to a discussion
of the approach that EPA employed to address the salient features and implications of mineral processing
waste generation and management.
2.1 EPA Data Collection Activities
After a review of the issues surrounding the Mining Waste Exclusion for mineral processing wastes
and its history, EPA's Office of Solid Waste conducted a number of data collection activities to supplement
and update previous work. The focus of most of these efforts was site-specific. As a consequence, EPA has
been able to compile detailed facility- and sector-specific information, which the Agency has used extensively
to prepare this report as well as a series of rulemakings which, in combination, have clarified the boundaries
of the Mining Waste Exclusion as it applies to mineral processing wastes (as discussed above). The major
information-gathering initiatives are identified and discussed in the following paragraphs.
Public Comments
Over the course of the past several years, EPA has received a considerable volume of written
comments addressing the scope of the Mining Waste Exclusion for mineral processing wastes. The Agency
has reviewed these comments, and has utilized pertinent information to supplement its knowledge of waste
generation and management, product markets, waste management alternatives, and other topics related to this
report.
1989 National Survey of Solid Wastes from Mineral
Processing Facilities (SWMPF Survey)
In early 1989, EPA prepared and submitted a written questionnaire to the operators of approximately
200 facilities that the Agency believed generated one or more solid wastes that might qualify for the Mining
Waste Exclusion. These facilities were identified from information in existing Agency files, statements made
in public comments on related proposed rulemakings, and from data supplied by the U.S. Bureau of Mines
(BOM). The questionnaire was designed to elicit information on waste generation and management at mineral
processing facilities, as well as on the operational characteristics of the facilities. The majority of the questions
included in the survey questionnaire addressed waste management, and were ordered so as to "track" the wastes
of interest from the point of generation through the ultimate disposition of all residuals.
Facility operator responses to the questionnaire provide nearly complete coverage of the facilities that
currently generate one of more of the 20 special study wastes. Coverage for many of the 20 waste streams is
complete, i.e., EPA has a census of all current generators of all but a few of these wastes. Responses to the
questionnaire were encoded and entered into a computerized data base, which EPA has used in assembling
the analyses described below. A description of the survey is presented in Appendix B-l to this document.
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2-2 Chapter 2: Methods and Information Sources
Copies of the survey instrument, as well as any non-confidential individual company responses to the
questionnaire, may be found in the supporting docket for this report.
1989 Mineral Processing Waste Sampling and Analysis
Because many of the wastes considered in this report had not been studied by OSW previously, and
because existing data for some of the other wastes is sparse, EPA conducted a waste sampling and analysis
program during the summer of 1989. The Agency's field sampling teams visited 37 mineral processing
facilities, recorded observations regarding operational practices, took photographs of waste management
activities, and collected samples. In many cases, EPA took samples of candidate special mineral processing
wastes on both an "as-generated" basis and on an "as-managed" basis. Analytical data derived from wastes as-
generated were used extensively in support of the recent series of rulemakings addressing the scope of the
Mining Waste Exclusion, while the as-managed data have been used as a primary source of waste
characterization data in preparing this report. These data may be found in summarized form in the supporting
docket for this report, while a description of EPAs 1989 waste sampling study is presented in Appendix B-2
to this report.
Damage Case Collection
1b respond to the need to describe "documented cases in which danger to human health or the
environment has been proved," (referred to in this report as "damage cases") as directed by the RCRA statute,
EPA conducted an exhaustive examination of the extent to which any of the wastes considered in this report
have been implicated in environmental contamination incidents. This effort began by contacting appropriate
staff people in all EPA regions and states in which one or more facilities that does or did generate one of the
20 special mineral processing wastes is located. Where telephone contacts indicated that relevant damage case
information might exist at the regional or state level, the information was obtained through the mail or
through visits with state/local officials having regulatory jurisdictii over mineral processing waste
management.
In some cases, personnel also visited the sites being evaluated. While in the field, EPA
representatives obtained copies of information that might be relevant to evaluating a particular damage case.
The result of this effort is a compilation of information regarding the past and present management practices
that have been applied to special mineral processing wastes, and the environmental or human health
consequences of these practices. Damage case findings are summarized by mineral commodity sector in the
chapters that follow; the individual sites that have been evaluated in detail are listed in Appendix B-3. More
extensive discussions and supporting evidence are provided in a technical background document that may be
found in the supporting docket for this report.
EPA Site Visits
In addition to the waste sampling and damage case collection efforts described above, staff visited a
number of active mineral processing operations during 1989 and 1990 in order to enhance the Agency's general
understanding of the processes whereby special mineral processing wastes are generated, and of the techniques
by which they are and could be managed. In total, EPA headquarters staff have, during the past two years,
been on site and have observed the production and waste management operations at several dozen facilities
representing all twelve of the mineral commodity sectors addressed herein. The knowledge and insights gained
during these visits have enabled the Agency to understand and critically evaluate the adequacy of current waste
management practices, and to draw conclusions and make recommendations regarding the regulatory status
of the special mineral ^ rocessing wastes.
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Chapter 1: Introduction 1 -3
• Hydrofluoric acid
fluorogypsum
process wastewater
• Lead -- slag from primary processing
• Magnesium -- process wastewater from primary magnesium processing by the anhydrous
process
• Phosphoric acid
phosphogypsum
process wastewater
• Titanium tetrachloride -- chloride process waste solids
• Zinc -- slag from primary processing
All other solid wastes from the processing of ores and minerals were removed from the Mining Waste
Exclusion as of the effective date of the January 23, 1990 final rule (July 23, 1990), and are subject to
regulation as hazardous wastes if they exhibit one or more characteristics of hazardous waste.
A summary of the important events in the rulemaking process and of the criteria that have been
developed by the Agency to identify the 20 special wastes from mineral processing operations that are the
subject of this report is presented in Appendix A (in Volume III) to this document.
1.2 Contents and Organization
This report addresses the following eight study factors required by §8002(p) of RCRA for the 20
mineral processing wastes listed above:
1. The source and volumes of such materials generated per ear;
2. Present disposal and utilization practices;
3. Potential danger to human health and the environment from the disposal and
reuse of such materials;
4. Documented cases in which danger to human health or the environment has
been proved;
5. Alternatives to current disposal methods;
6. The costs of such alternatives;
7. The impacts of these alternatives on the use of phosphate rock, uranium ore,
and other natural resources; and
8. The current and potential utilization of such materials.
In addition, the report includes a review of applicable state and federal regulations so that decisions
that derive from the report avoid duplication of existing requirements.
The report consists of three volumes, as follows:
Volume I: Summary and Findings
• This volume provides an overview of the methods used to conduct the study, the decision
criteria used by EPA in reaching its tentative conclusions, and the Agency's preliminary
findings with respect to each of the 20 mineral processing wastes that are within the scope of
the study.
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1-4 Chapter 1: Introduction
Volume II: Methods and Analyses
• Chapter 1. Introduction, summarizes the scope, contents, and organization of the report.
• Chapter 2. Methods and Information Sources, presents an overview of the data sources
used to prepare this report and the methods used to interpret these data.
• Chapters 3 through 14. summarize the information and analysis performed with respect
to the study factors for the 20 mineral processing wastes, organized by 12 commodity
sectors, as follows:
Alumina
Chromium (sodium chromate and dichromate)
Coal gas
Copper
Elemental phosphorus
Ferrous metals (iron and carbon steel)
Hydrofluoric acid
Lead
Magnesium
Phosphoric acid
Titanium tetrachloride
Zinc
Each of these 12 chapters has seven sections. The first section provides a brief overview of the
industry, including the types of production processes us -i and the number and location of
operating facilities. The second section summarizes information on waste characteristics, as
well as waste generation and management practices (study factors 1 and 2), while the third
section provides a discussion of potential for and documented cases of danger to human health
or the environment (study factors 3 and 4). The fourth section summarizes applicable federal
and state regulatory controls (as suggested by § 8002(p) of RCRA, independent of the eight
study factors). The fifth section discusses alternative waste management practices and potential
utilization (study factors 5 and 8), while the sixth section discusses costs and impacts of
alternative practices (study factors 6 and 7). The seventh and final section of each chapter
summarizes the findings of the study for each commodity sector and the special waste(s)
generated therein.
Volume III: Appendices
• Appendices A - E present additional information on the history of the Mining Waste
Exclusion for mineral processing wastes; significant EPA data collection activities; risk
assessment methodology and assumptions; existing regulatory controls; and cost and
economic impact assessment methodology, assumptions, and results.
Additional documentation regarding the methods, data sources, and assumptions used in preparing
this report and the analyses contained herein may be found in the RCRA docket (docket number F-90-RMPA-
FFhFF).
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Chapter 1
Introduction
Section 3001(b)(3)(A)(ii) of the Resource Conservation and Recovery Act (RCRA) excludes "solid
waste from the extraction, beneficiation, and processing of ores and minerals" from regulation as hazardous
waste under Subtitle C of RCRA, pending completion of a Report to Congress required by §8002(pj and a
determination by the EPA Administrator either to promulgate regulations under Subtitle C or that such
regulations are unwarranted (as required by §3001(b)(3)(C)). In 1985, EPA published the required Report
to Congress on solid wastes from mineral extraction and beneficiation.1 On July 3,1986 (51 FR 24496). EPA
published a determination that regulation of such wastes under Subtitle C of RCRA was not warranted.
This report has been prepared in response to the requirements of §3001(b)(3) and §8002(p) that EPA
study solid waste from mineral processing operations that were included within the exemption -- referred to
as special wastes -- and prepare a Report to Congress on the findings of the study. This introduction provides:
(1) a description of the scope of the mineral processing waste exemption; and (2) an overview of the content
and organization of this report.
1.1 The Scope of the Mineral Processing Waste Exemption
On October 21, 1976, Congress enacted the Resource Conservation and Recovery Act (RCRA)
(Pub. L. 94-580). Section 3001 of RCRA mandated that the EPA Administrator "promulgate regulations
identifying characteristics of hazardous waste, and listing particular hazardous wastes which shall be subject
to the provisions of this subtitle." Section 3004 required the Administrator to promulgate standards applicable
to owners and operators of hazardous waste treatment, storage, and disposal facilities.
In response to these requirements, EPA proposed regulations f. managing hazardous wastes under
Subtitle C of RCRA on December 18, 1978 (43 FR 58946). In this regulatory proposal, EPA proposed to
defer most of the RCRA Subtitle C requirements for six categories of wastes, which it termed "special wastes,"
until information could be gathered and assessed and the most appropriate regulatory approach determined.
EPA identified mining wastes as one of six such "special wastes" that were generated in large volumes, were
thought to pose less risk to human health and the environment than wastes regulated as hazardous wastes, and
for which the proposed technical requirements implementing Subtitle C might not be appropriate.2
In 1979, Congress began work on reauthorization of RCRA During the reauthorization process, Rep.
Thomas Bevill (Alabama) offered an amendment (now frequently referred to as the Bevill Amendment) which,
among other things, modified §3001 to temporarily exempt "solid waste from the extraaion, beneficiation, and
processing of ores and minerals, including phosphate rock and uranium ore" (along with two other categories
of waste) from Subtitle C regulation, pending completion of certain studies. On October 12, 1980, Congress
enacted the Solid Waste Disposal Act Amendments of 1980 (Pub. L. 96-482), which added §3001(b)(3)(A)(i-
iii) (the Bevill. Amendment) to RCRA3 These amendments also added §8002(p), which required the
Administrator to study the adverse effects on human health and the environment, if any, of wastes from the
disposal and utilization of "solid waste from the extraction, beneficiation, and processing of ores and minerals,
1 U. S. Environmental Protection Agency, 1985. Report to Congress on Wastes from the Extraction and Beneficiation of Metallic
Ores. Phosphate Rock. Asbestos. Overburden from Uranium Mining, and Oil Shale. EPA/530-SW-85-033, Washington, D.C.
- The other five proposed "special wastes" specifically identified in the 1978 proposed rule were cement kiln dust waste; utility
waste; phosphate rock mining, beneficiation, and processing waste; uranium mining waste; and oil and gas drilling muds and oil
production bnnes.
3 The 1980 Amendments also contained §3001(b)(3)(B)(iii), which provides authority for EPA to regulate the use of solid waste
from the extraction, beneficiation, and processing of phosphate rock or overburden from uranium mining in construction or land
reclamation, so as to prevent radiation exposure which presents an unreasonable risk to human health.
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1-2 Chapter 1: Introduction
including phosphate rock and overburden from the mining of uranium ores," and submit a Report to Congress
on its findings. In addition, the 1980 amendments added §3001(b)(3)(C), which requires the Administrator
to make a regulatory determination, within six months of the completion of the §8002(p) studies, whether to
regulate the wastes under Subtitle C of RCRA.
In response to the 1980 RCRA amendments, on November 19, 1980, EPA published an interim final
amendment to its hazardous waste regulations to reflect the provisions of the Bevill Amendment (45 FR
76618). The regulatory language incorporating the exclusion was identical to the statutory language, except
EPA added the phrase "including coal." In the preamble to the amended regulation, however, EPA tentatively
interpreted the exclusion to include "solid waste from the exploration, mining, milling, smelting, and refining
of ores and minerals."
In 1985, EPA proposed to narrow the scope of the exclusion as it applied to mineral processing wastes
(50 FR 40292, October 2,1985), although EPA subsequently withdrew this proposal (51 FR 36233, October 9,
1986). The Agency's decision to withdraw its 1985 proposal was challenged in court (Environmental Defense
Fund v. EPA, 852 F.2d 1316 (D. C. Cir. 1988), cert, denied 109 S. Ct. 1120 (1989) (EDF v. EPA)). In this case,
the petitioners contended, and the Court of Appeals agreed, that EPA's interpretation of the scope of the
Bevill amendment as it applies to mineral processing wastes was "impermissibly over-broad." In reaching this
decision, the Court found that Congress intended the term "processing" in the Bevill amendment to include
only those wastes from processing ores or minerals that met the "special waste" criteria -- that is, "high volume,
low hazard" wastes. 852 F.2d at 1328-29.
Through a rulemaking process completed with the publication of a final rule on January 23,1990 (55
FR 2322),4 the Agency has established that the temporary exemption from Subtitle C requirements
established by the Bevill Amendment for mineral processing wastes and, therefore, the scope of this report
is limited to 20 mineral processing wastes generated by approximately 91 facilities located within 29 states,
representing 12 mineral commodity sectors, as follows:
• Alumina ~ red and brown muds from bauxite refining
• Chromium (Sodium chromate/dichromate') - treated resid ue from roasting/leaching of chrome
ore
• Coal gas
-- gasifier ash from coal gasification
-- process wastewater from coal gasification
• Copper
slag from primary processing
calcium sulfate wastewater treatment plant sludge from primary processing
slag tailings from primary processing
• Elemental phosphorus -- slag from primary production
• Ferrous Metals (iron and carbon steel")
iron blast furnace air pollution control dust/sludge
iron blast furnace slag
basic oxygen furnace and open hearth furnace air pollution control dust/sludge
basic oxygen furnace and open hearth furnace slag
4 This rulemaking process also included publication of a proposed rule on October 20,1988 (53 FR 41288), a proposed rule on
Apnl 17, 1989 (54 FR 15316), a Qnal rule on September 1, 1989 ( 54 FR 36592), and a proposed rule on September 25, 1989 (54 FR
39298).
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REPORT TO CONGRESS
ON
SPECIAL WASTES FROM MINERAL PROCESSING
Methods and Analyses
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Summary and Findings 17
hazardous waste management standards, but instead to be retained within the Mining V&ste Exclusion for
mineral processing wastes. If such a finding is appropriate, EPA believes that it would need to be conditioned
on the premise that major steps be taken to take near term actions to control releases from the facilities
producing these waste streams. Some corrective measures are already being taken under a variety of Agency
authorities (i.e., RCRA, Superfund, CWA) and more can and will be undertaken. EPA believes that the states
must act to address the most immediate problems posed by these wastes, as well as any of the other mineral
processing special wastes that have been found in this report to pose significant actual or potential hazard to
human health or the environment. To assist in this effort, EPA would provide technical and other resource
support to the involved states to improve their programs. If near term actions did not result in adequate
control of such wastes, EPA would then take action to reconsider its regulatory determination and could
designate certain waste streams as Subtitle C hazardous wastes.
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Summary and Findings 15
• Current management practices for hydrofluoric acid process wastewater have not
prevented release at one of the currently active facilities. There is a potential for
development of additional domestic hydrofluoric acid production capacity, and the
corresponding construction of new facilities. New facilities may be located in sensitive
environmental settings given that the principal feedstock (acid-grade fluorspar) is
generally imported and facility locations with ready access to water transportation are
most likely.
• In the case of calcium sulfate wastewater treatment plant sludge from primary copper
processing, applicable solid waste regulations are limited in states where it is currently
generated and generation of this waste at additional facilities appears likely.9 At least
some of these additional facilities are in environmental settings that may have a greater
potential for risk than the facilities where the waste is currently generated. Ground-
water contamination at one facility may be due at least in part to disposal of the sludge.
• Current management practices contributing to documented damages associated with lead
slag are not adequately addressed by current regulations.
• Chloride process waste solids from titanium tetrachloride production are generated by
facilities in eight states, some of which have relatively few solid waste regulations that
are applicable to the management of this waste. Construction of several new facilities
is expected and these facilities may be located in sensitive environmental settings given
that the principal feedstock is generally imported and facility locations with ready access
to water transportation are most likely. In addition, EPA is concerned that under some
circumstances, chloride process waste solids from titanium tetrachloride production may
pose some radiation risk. As a result, EPA plans to investigate further the potential for
exposure and associated radiation risk associated with this waste and, if appropriate,
take steps to limit such risks under authorities provided by RCRA and other statutes.
Tb conduct Step 3 of the analysis process under Approach 1A, EPA estimated the cost of regulating
each of these wastes under full Subtitle C requirements. The Agency the- compared the costs for full Subtitle
C regulation to the estimated costs that might result from regulation ur jer Subtitle D requirements similar
to those being developed for mining wastes ("Subtitle D-Plus"). For three of the four wastes (calcium sulfate
wastewater treatment plant sludge from primary copper processing, slag from primary lead processing, and
chloride process waste solids from titanium tetrachloride production), the estimated costs for full Subtitle C
regulation would be significantly larger and the associated impacts would be more significant at nearly all
facilities than the estimated costs of regulation under the Subtitle D-Plus scenario. Using this approach, EPA
would tentatively conclude that regulation of these three wastes under Subtitle C is not warranted.
For process wastewater from hydrofluoric acid production, EPA found that the estimated compliance
costs for regulation under full Subtitle C and regulation under the Subtitle D-Plus scenario were comparable
and that the likely economic impacts were not expected to be significant. Using this approach to the cost
analysis, EPA would tentatively conclude that process wastewater from hydrofluoric acid production may
warrant regulation under Subtitle C
Comparison of Subtitle D-Plus and Subtitle C-Mlnus (Approach 1B)
Under Approach IB to conducting Step 3, EPA estimated the cost of managing these four wastes
under a Subtitle C scenario that utilizes flexibility provided by RCRA §3004(x) (Subtitle C-Minus). The
Agency then compared the costs for Subtitle C-Minus regulation (rather than full Subtitle C regulation, as in
Approach 1A) to the estimated costs that might result from regulation under Subtitle D requirements similar
9 Additional facilities where the calcium sulfate wastewater treatment sludge may be generated include both existing copper
smelting/refining facilities that do not currently generate the waste and potential new smelting/refining facilities, including a facility on
the Gulf Coast of Texas.
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16 Summary and Findings
to those being developed for mining wastes (Subtitle D-Plus). EPA found that the estimated costs for the
Subtitle C-Minus and Subtitle D-Plus scenarios are similar for nearly all facilities.
4.2 Application of the RCRA §8002(p) Study Factors and Additional
Considerations: Approach 2
Section 8002(p) of RCRA and the decision in Environmental Defense Fund v. EPA, 852 F.2d 1309
(D.C. Cir. 1988) make it clear that the Agency may and should consider the specific factors of §8002(p)(l)-(8)
in making its decision regarding the appropriate regulatory status of special wastes from mineral processing
In addition, the Agency believes that it may be appropriate to consider other factors relating to the broader
goals and objectives of the Agency, such as developing and maintaining strong state mining and mineral
processing waste regulatory programs and facilitating implementation of federal programs (see Step 4 of the
discussion of the decision rationale in Section 3.3 above).
The analysis of the §8002(p) study factors presented above indicates that management of one, and
perhaps as many as four, mineral processing special wastes may be appropriate for regulation under Subtitle
C if only the study factors are considered, primarily because: (1) they have or could pose a significant risk to
human health and the environment under current management practices or plausible mismanagement
scenarios; and (2) the costs and impacts of regulation under full Subtitle C (for one waste) or Subtitle C-Minus
(for three additional wastes) are estimated to be comparable to the costs associated with regulation under a
Subtitle D-Plus program. In the case of process wastewater from hydrofluoric acid production, the estimated
costs for the various scenarios are similar in large pan because EPA has projected that requirements that
would be protective of human health and the environment under Subtitle C-Minus, and under full Subtitle
C as well, might be similar to those that may be required under a Subtitle D-Plus program. Because of the
potential similarity between Subtitle C-Minus and Subtitle D-Plus requirements, as well as broader Agency
objectives, EPA believes that it may be appropriate to include consideration of the additional factors of state
program development for mining and mineral processing waste streams, neluding federal program oversight,
in order better to distinguish between these two regulatory scenarios.
Many states have recently or are currently expanding the scope and requirements of their regulatory
programs as they apply to mineral processing wastes. For example, Florida has recently developed a policy
that requires additional controls, such as liners, for new or expanded phosphogypsum stacks and is developing
proposed regulations to update this policy and expand its scope to include phosphoric acid process wastewater.
Missouri passed the Metallic Minerals ^ste Management Act in 1989, and implementing regulations are
being developed, which require permits, closure plans, maintenance plans, and provisions for financial
assurance. Pennsylvania has proposed Residual Waste Regulations that, if promulgated, would require permits
with provisions for liners, leachate collection systems, monitoring wells, and disposal of leachate for special
wastes from iron and steel production and zinc slag (as well as other wastes). Similarly, Delaware, Ohio, and
Tennessee have all recently developed revised solid waste regulations that will increase the stringency of
requirements for management of special wastes. Some other states, such as Indiana and Kentucky, already
have programs that specify management standards for mineral processing wastes.
In addition, some of these and many other states are currently working with EPA in the development
of a regulatory program for mining wastes. This program is designed to be site-specific, risk based, and
comprehensive. It also is being targeted to address the characteristics of mining wastes and site conditions
at mining sites.
EPA believes that it may be appropriate to facilitate both development and maintenance of strong
state programs and implementation of any federal regulations that may be necessary for mineral processing
wastes by regulating all special wastes from mineral processing under Subtitle D of RCRA. Some mining and
mineral processing wastes may be excluded from any further federal regulation under RCRA.
In light of these considerations, the results of Approach 2 indicate that it may be appropriate for the
waste streams identified above for potential Subtitle C (full C or C-Minus) regulation not to be subject to
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Summary and Findings 13
In addition, EPA found that the available data indicate that air pollution control (APC) dust/sludge
from iron blast furnaces and from basic oxygen and open hearth furnaces used to make carbon steel exhibit
the characteristic of EP toxicity at some facilities. For both types of dust and sludge, relatively few of the
samples and facilities tested yielded EP-toxic results (for at most two constituents) and the magnitude of the
exceedances was generally low. No damage cases were identified for either type of dust/sludge, either for on-
site or off-site management. In addition, several facilities recycle rather than dispose the dust, the facilities
are generally not in high risk settings, and construction of new facilities is not likely.
EPA also found that the potential for hazard associated with two other wastes, red and brown muds
from bauxite refining and gasifier ash from coal gasification, was comparatively low, except for the radionuclide
content of the wastes; in addition, no documented damages attributable to these two wastes were identified.6
For both of these wastes, however, available data indicate that under some circumstances (e.g., use of the
wastes in home building materials) the wastes may pose some radiation risk. As a result, EPA plans to
investigate further the potential for exposure and associated radiation risk associated with use of these two
mineral processing special wastes and, if appropriate, take steps to limit such risks under authorities provided
by statutes other than RCRA.
The radionuclide content, and the associated potential for radiation risk, is also of concern in three
other wastes: slag from elemental phosphorus production, and phosphogypsum and process wastewater from
phosphoric acid production. With respect to slag from elemental phosphorus production, EPA found that
average life-time cancer risks range from 4x10"* to IxlO'3 in Soda Springs and Pocatello, Idaho as a result of
the use of the slag in a wide range of construction applications. In other respects, the potential and
documented danger associated with non-radioactive contaminants contained in elemental phosphorus slag
appears to be relatively low because: (1) the slag does not exhibit any of the characteristics of hazardous waste;
and (2) there are no documented damage cases.7 In addition, construction of additional facilities in the
foreseeable future appears unlikely. EPA plans to use the authority of RCRA §3001(b)(3)(B)(iii) to ban the
use of this material in construction and/or land reclamation when the Agency issues its regulatory
determination for mineral processing wastes. EPA is soliciting comr nts on the appropriate regulatory
language that should be used and how such a ban should be implemen:. 1
In the case of phosphogypsum, radionuclide hazards associated with air releases from gypsum stacks
and off-site uses of phosphogypsum are being addressed by the Agency under 40 CFR, Pan 61, Subpan R,
National Emission Standards for Hazardous Air Pollutants (NESHAP), Radon Emissions from
Phosphogypsum Stacks (54 FR 51654, December 15, 1989; 55 FR 13480, April 10, 1990; 55 FR 13482, April
10, 1990).
Phosphogypsum and phosphoric acid process wastewater are also of concern because damage case
information indicates that both closed and currently active phosphogypsum stacks (in which both the
phosphogypsum and the wastewater are managed) and wastewater cooling ponds have caused and/or are
causing ground-water contamination at many facilities. In addition, available data indicate that
phosphogypsum tested EP toxic at one of ten facilities, and process wastewater exhibits the characteristic of
corrosivity at most facilities and the EP-toricity characteristic at some facilities. Current regulations are
apparently not adequate to prevent contamination (although this situation may change as state regulatory
programs improve), so the potential costs of regulation under Subtitle C were examined in the third stage of
the evaluation. EPA estimated that the incremental annualized cost of either full Subtitle C regulation or the
Subtitle C-Minus scenario for phosphogypsum and process wastewater, as compared to the Subtitle D-Plus
scenario developed for cost estimating purposes, could exceed $500 million and $50 million respectively, and
could significantly affect several facilities. At facilities that EPA estimates could be significantly affected by
costs associated with the Subtitle C or Subtitle C-Minus scenarios, the estimated costs of the Subtitle D-Plus
* Ground-water contamination at the Dakota Gasification facility in North Dakota was identified, but the source of the
contamination appears to be wastes other than the gasifier ash.
Ground-water contamination has been identified at one site, but it appears that wastewater was the source rather than slag.
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14 Summary and Findings
scenario, expressed as a percent of the value of shipments, are substantially less at seven facilities. The
estimated impacts associated with Subtitle C or C-Minus regulation at these facilities would be expected to
be significant, and it is unlikely that these facilities could pass along their higher costs. EPA considered the
combined costs of Subtitle C requirements for phosphogypsum and process wastewater because: (1) these two
wastes are typically co-managed; and (2) the compliance costs associated with both wastes would apply to each
facility. EPA is aware, however, that only a portion of the total process wastewater flow is typically co-
managed with the phosphogypsum. The Agency may investigate the feasibility of separate management of
these wastes, as well as separating various wastewater streams in the context of this decisionmaking and the
development of the mining waste program under Subtitle D.
In any case, however, EPA is concerned that under some circumstances process wastewater from
phosphoric acid may pose some radiation risk that would not be addressed by the NESHAP regulation noted
above. As a result, EPA plans to investigate further the potential for exposure and associated radiation risk
associated with this waste and, if appropriate, take steps to limit such risks under authorities provided by
RCRA and other statutes.
Wastes EPA Might Tentatively Consider for Regulation
Under RCRA Subtitles C or D
For the remaining four wastes (calcium sulfate wastewater treatment plant sludge from primary copper
processing, slag from primary lead processing, process wastewater from hydrofluoric acid production, and
chloride process waste solids from titanium tetrachloride production), EPA proceeded to evaluate the
estimated incremental compliance costs and associated impacts in Step 3 of the analysis in two ways. First,
EPA examined the estimated costs of regulation under Subtitle D (using the "D-Plus" scenario) relative to the
estimated costs of full Subtitle C regulation (Approach 1A). Second, EPA examined the estimated cost of
Subtitle D-Plus regulation relative to the cost of regulation under a Subtitle C scenario that utilizes flexibility
provided by RCRA §3004(x) (Approach IB). These two analyses are discussed below along with the results
of analysis Steps 1 and 2 for each of the wastes. As already indicated, t . Subtitle C-Minus and Subtitle D-
Plus scenarios are based on the Agency's preliminary assessment of hov> regulatory requirements might be
tailored for mineral processing wastes. Because of this, the Agency is unsure whether the cost/impacts in these
comparisons are fully appropriate and specifically requests comments on them. The fact that a hypothetical
Subtitle D-Plus scenario was used for comparison does not mean that any or all of these wastes will necessarily
be proposed for further regulation.
Companion of Subtttto D-Plus and Full Subtitle C (Approach 1A)
In applying Steps 1 and 2 of the analysis process, EPA found that each of these four special wastes
have posed or may pose a danger to health or the environment. Available data indicate that all four of the
wastes exhibit one or more of the characteristics of hazardous wastes. All of the wastes except process
wastewater from hydrofluoric acid production exhibit the characteristic of EP toxicity at at least one facility.
Process wastewater from hydrofluoric acid production is corrosive at all facilities where it is generated.
Documented damages associated with current lead slag management practices were identified and the potential
for damages exists for the other wastes as well. Ground-water contamination that may in pan be attributable
to calcium sulfate sludge from primary copper processing and chloride process waste solids from titanium
tetrachloride production was identified at at least one facility that generates one of these wastes.8
In addition, the Agency is not confident that current practices and regulations are adequate to prevent
further danger to health or the environment from these four wastes. Specific reasons are as follows:
8 Attribution of the observed ground-water contamination at these sites was not possible due to co-management of the special
wastes with other wastes, the close proximity of other waste management units, and/or a long history of production and waste
management activities at the site.
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Summary and Findings 11
4.0 Findings
Section 3001(b)(3)(C) of RCRA requires that the Agency determine, based on the findings of this
report, and public hearings and comment, either to promulgate regulations under Subtitle C of RCRA for the
wastes covered by this study or determine that such regulations are unwarranted. Accordingly, to facilitate
comment on this report and the subsequent preparation by the Agency of the required "regulatory
determination," this section presents EPA's findings regarding the 20 special wastes from mineral processing
based on two separate approaches. These two approaches include:
• Application of the RCRA §8002(p) Study Factors, which discusses the regulatory
approach (i.e., Subtitle D or Subtitle C) that the Agency tentatively concludes is
appropriate for each of the 20 mineral processing wastes if the study factors listed in the
statute aione are considered; and
• Application of the RCRA §8002(p) Study Factors and Additional Considerations, which
discusses (1) additional factors that the Agency believes may be appropriate to consider
in making a "regulatory determination" and (2) the tentative conclusions that may be
drawn that include consideration of these additional factors.
EPA solicits comments on both of these approaches and the tentative conclusions presented below.
With respect to the decision-making approaches, EPA solicits comments on: (1) what factors the Agency
should consider in making the required regulatory determination; (2) what information should be used to
evaluate these factors; and (3) the relative weight that the factors should be given in developing a regulatory
determination.
4.1 Application of the RCRA §8002(p) Study Factors: Approach 1
As discussed above, RCRA §8002(p) specifies eight factors that the Agency shall include in the
analysis performed for this report and suggests that EPA also examine federal and state agency programs to
avoid duplication of effort. This section presents a summary of the Ager y's analysis of these factors and the
possible conclusions, pending receipt and analysis of public comments, that EPA might make regarding the
appropriate regulatory status of the 20 mineral processing special wastes covered by this report. The 20
mineral processing special wastes are discussed in two groups: (1) wastes that the Agency might recommend
regulating under Subtitle D of RCRA; and (2) wastes that the Agency might tentatively consider for regulation
under Subtitles C or D.
Wastes EPA Might Tentatively Recommend to Remain Under RCRA
Subtitle D
The available data, the analysis presented in this report, and consideration of the RCRA §8002(p)
study factors suggest that regulation under Subtitle C of RCRA is unwarranted for the following 16 mineral
processing wastes:
• Red and brown muds from bauxite refining;
• Treated residue from roasting/leaching of chrome ore;
• Gasifier ash from coal gasification;
• Process wastewater from coal gasification;
• Slag from primary copper processing;
• Slag tailings from primary copper processing;
• Slag from elemental phosphorus production;
• Iron blast furnace slag;
• Basic oxygen furnace and open hearth furnace slag from carbon steel production;
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12 Summary and Findings
• Air pollution control dust/sludge from iron blast furnaces;
Air pollution control dust/sludge from basic oxygen furnaces and open hearth furnaces
from carbon steel production;
• Fluorogypsum from hydrofluoric acid production;
• Process wastewater from primary magnesium processing by the anhydrous process;
• Process wastewater from phosphoric acid production;
• Phosphogypsum from phosphoric acid production; and
• Slag from primary zinc processing.
In using the study factors listed in RCRA §8002(p), EPA used the approach described above in
Section 3 to examine: (1) the potential for and documented danger to human health and the environment; (2)
the need for additional regulations; and (3) the costs and impacts of Subtitle C regulation.
EPA did not find significant actual or potential danger associated with the following three wastes,
based on waste characteristics, management practices, and damage case investigations:
• Treated residue from roasting/leaching of chrome ore;
• Process wastewater from coal gasification; and
• Slag tailings from primary copper processing.
None of these wastes exhibit a characteristic of hazardous waste and no documented damages were identified
as associated with their management.
The other thirteen wastes listed above were identified as having some actual or potential hazard
associated with current management practices or plausible mismanagement scenarios, and so were subsequently
evaluated in the second stage of the process.
In the second stage of the evaluation, EPA identified four wa^ ;s that did not exhibit a hazardous
characteristic (with the exception of one sample of copper slag at one facility) but for which documented cases
of adverse environmental impacts that affected surface water were identified at at least one facility:
• Iron blast furnace slag;
• Slag from primary copper processing;
Basic oxygen furnace and open hearth furnace slag from carbon steel production; and
• Fluorogypsum from hydrofluoric acid production.
In all four cases, however, these surface water releases (one of which occurred via ground water) have been
and/or are being addressed under existing regulatory authorities at the state and/or federal level. In addition,
the potential for risks associated with management of these wastes at potential new facilities is not likely to
be greater than at the existing facilities. In the case of fluorogypsum, however, the available data indicate that
the radionuclide content of the waste is such that under some circumstances (e.g., use of the wastes in
construction) the waste may pose some radiation risk. As a result, EPA plans to investigate further the
potential for exposure and associated radiation risk for fluorogypsum and, if appropriate, take steps to limit
such risks under authorities provided by RCRA and other statutes.
EPA found that two wastes exhibited one or more of the hazardous characteristics, slag from primary
zinc processing and process wastewater from primary magnesium processing by the anhydrous process.
However, each is generated by a single facility, neither of which have documented damages after about 50 and
20 years of operation, respectively. In both cases, market conditions and production processes are such that
construction of additional facilities in the foreseeable future is unlikely. In addition, state regulations are in
effect for the one primary magnesium facility and being revised/strengthened for the primary zinc processing
facility. EPA plans to investigate further off-site uses of zinc slag for uses that constitute disposal.
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Summary and Findings 9
It should be noted that EPA has done its best to develop and analyze alternatives to current disposal
methods. However, these scenarios represent an assessment of how regulatory requirements miEht be tailored
to reflect the unusual characteristics of mineral processing wastes, that is, the assumptions made here in
developing these scenarios may not resemble any actual Subtitle C-Minus or Subtitle D-Plus requirements that
may be developed by the Agency in the future. As a result, EPA solicits comments on the regulatory scenarios
that the Agency has used and the appropriateness of the underlying assumptions for the possible future
development of regulatory programs under Subtitle D or under Subtitle C using the flexibility provided by
RCRA §3004(x).
In considering whether Subtitle C regulation may be warranted or not, EPA is considering how or
whether to implement the flexibility provided by RCRA §3004(x) to the extent that it can do so and continue
to ensure human health and environmental protection. Specifically, EPA would consider this flexibility in
establishing treatment standards for land disposal of these newly identified wastes under 40 CFR Part 268 in
separate rulemaking under §3004(g)(4) and would develop corrective action requirements on a site-specific
basis as part of the permitting process. With respect to the flexibility for minimum technology requirements
(§3004(o) and §3005(j)), EPA solicits comments on how best to implement the flexibility provided by §3004(x),
such as establishing requirements on a site-specific basis as part of the permitting process or development of
revised standards under Subtitle C regulations.
The step-wise process that the Agency applied to the available information is outlined below.
Step 1. Does management of this waste pose human health/environmental
problems? Might current practices cause problems in the future?
Critical to the Agency's decision-making process is whether each special waste either has caused or
may cause human health or environmental damage. To resolve this issue, EPA has posed the following key
questions:
1. Has the waste, as currently managed, caused documented ! . man health impacts
or environmental damage?
2. Does EPA's analysis indicate that the waste may pose a significant risk to
human health or the environment at any of the sites that generate it (or in off-
site use), under either current management practices or plausible mis-
management scenarios?
3. Does the waste exhibit any of the characteristics of hazardous waste?
If the answer to any of these three questions was yes, then EPA concluded that further evaluation was
necessary. If the answer to all of these questions was no, then the Agency tentatively concluded that regulation
of the waste under RCRA Subtitle C is unwarranted.
Step 2. Is more stringent regulation necessary and desirable?
If the waste has caused or may potentially cause human health or environmental impacts under
conservative risk assumptions, then EPA concluded that an examination of alternative regulatory controls was
appropriate. Given the context and purpose of the present study, the Agency focused on an evaluation of the
likelihood that such impacts might continue or arise in the absence of Subtitle C regulation, by posing the
following three questions:
1. Are current practices adequate to limit contaminant release and associated
risk?
2. What is the likelihood of new facilities opening in the future and generating
and managing the special waste in a different environmental setting than those
examined for this report?
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10 Summary and Findings
3. Are current federal and state regulatory controls adequate to address the
management of the waste?
If current practices or existing regulatory controls are adequate, and if the potential for actual future impacts
is low (e.g., facilities in remote locations, low probability of new facilities being constructed, low likelihood
of actual risk), then the Agency may tentatively conclude that regulation of the waste under Subtitle C is
unwarranted. Otherwise, further examination of regulatory alternatives is necessary.
Step 3. What would be the operational and economic consequences of a
decision to regulate a special waste under Subtitle C?
If, based upon the previous two steps, EPA believed that a waste might potentially be a candidate for
regulation under Subtitle C, then the Agency estimated and evaluated the costs and impacts of two regulatory
alternatives that are based upon Subtitle C, and one alternative that reflects one possible approach that might
be taken under RCRA Subtitle D ("Subtitle D-Plus"). Two evaluations were performed. The first focused
on the magnitude, distribution, and significance of the incremental costs of regulation under full Subtitle C
as compared to the Subtitle D-Plus scenario for each potentially affected facility. The second focused on
incremental costs and impacts associated with regulation under the Subtitle C-Minus scenario as compared
to Subtitle D-Plus. The key questions in the Agency's decision-making process for both comparisons were as
follows:
1. Are predicted economic impacts associated with the full Subtitle C (or Subtitle
C-Minus in the case of the second comparison) scenario significant for any of
the affected facilities?
2. Are these impacts substantially greater than those that would be experienced
under the Subtitle D-Plus scenario?
3. What is the likely extent to which compliance costs cou : be passed through
to product markets or input costs could be reduced, i.e., j what extent could
regulatory cost burdens be shared?
4. In the event that costs are significant, could a large proportion of domestic
capacity or product consumption be affected?
5. What effects would hazardous waste regulation have upon the viability of the
beneficial use or recycling of the special waste?
In EPA's judgment, an ability to pass through costs or an absence of significant impacts suggested that Subtitle
C regulation (or Subtitle C-Minus in the case of the second comparison) might be appropriate for wastes that
pose significant risk. In cases in which the Subtitle C (or Subtitle C-Minus) scenario would impose widespread
and significant impacts on facilities, result in reductions in domestic capacity or supply, and/or deter the safe
and beneficial use of the waste, EPA tentatively concluded that regulation under some form of Subtitle D
program might be more appropriate.
Step 4. Additional Considerations
In this fourth step, which EPA only included in one of the two decision-making approaches, EPA
considered factors in addition to the §8002(p) study factors that relate to the broader goals and objectives of
the Agency, including developing and maintaining strong state programs to regulate mining and mineral
processing wastes. EPA believes that it may be appropriate to facilitate both development and maintenance
of strong state programs and implementation of federal regulations for mineral processing wastes by regulating
all special wastes from mineral processing under the mining wastes program being developed under Subtitle
D of RCRA The relevance of these additional factors, and their impact on EPA's findings, is discussed below.
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Summary and Findings 7
two reasons. First, some states do not have regulatory programs, meaning that federal requirements apply
directly. Second, the federal government has not delegated authority to states for implementing some
environmental protection statutes and regulations.
The initial phase of the analysis examined the relevant statutes and regulations pertaining to
hazardous waste, solid waste, air quality, and water quality as they might apply to the management of the
mineral processing special wastes, in general. The second phase of this analysis was to identify and evaluate
any specific regulations that pertain to any of the 20 special mineral processing wastes. The final phase of the
analysis involved contacting Regional EPA staff in those states that do not have federally approved programs
for implementation of the major environmental statutes, as well as relevant staff within other federal agencies
and departments, and performing a regulatory analysis of the implementation of all existing federal statutes
and regulations that pertain specifically to the management of the 20 special mineral processing wastes. The
findings of this review are contained within the twelve commodity-specific chapters, while descriptions of the
major federal statutes and regulations that affect mineral processing wastes management generally are provided
in Appendix D-l (in Volume III).
Requirements in Selected States
EPA's goal in this analysis was to determine the current regulatory stance of states with regard to the
mineral processing wastes generated by the 12 commodity sectors addressed in this report The analysis serves
more generally to help characterize current waste management and disposal practices taking place as a result
of state regulation.
The first step in the analysis focused on reviewing material in a previous EPA-sponsored study on
state-level regulation of mining and mineral processing wastes. The second step of EPA's analysis was to
perform a more detailed review of individual state statutes and regulations; this review was limited in scope
to a representative sample (18) of the 29 states containing facilities of interest for further analysis. While this
more detailed study addressed, in part, the regulatory status of special rrneral processing wastes, EPA found
that the scope of state programs was not always clear from the state st utory and regulatory language that
was reviewed. The final step of EPA's analysis, therefore, consisted of contacting state officials involved with
the implementation of legal requirements in order to learn how those statutes and regulations are interpreted
in practice, and to obtain facility-specific implementation information. The information compiled from these
contacts was combined with the existing information on statutory and regulatory requirements to produce a
final implementation analysis, which describes the existing regulatory structure applicable to the 20 mineral
processing wastes generated by the twelve commodity sectors considered in this Report to Congress.
Alternative Management Practices and Potential Utilization
Section 8002(p) of the RCRA statute requires that EPA consider alternatives to current disposal
methods, as well as the current and potential utilization of the wastes addressed by the Report to Congress.
In order to accomplish this, this report identifies demonstrated alternatives for waste management and
utilization. The costs, current use, potential use, and environmental impact of each alternative are evaluated
to the extent permitted by the information available.
Because the primary purpose of this report is to determine whether the regulation of the special
mineral processing wastes under Subtitle C is warranted, EPA focused its efforts and the discussion of waste
management alternatives presented herein on those wastes that potentially may be candidates for Subtitle C
regulation, excluding consideration of the costs and impacts of the various scenarios.
The focus of this analysis was on conducting a comprehensive computer-assisted literature search, then
evaluating the information obtained thereby. In some instances, more detailed information was solicited from
individual researchers, agencies, and trade associations. Detailed discussion of alternatives is limited in scope,
however, to those for which information is adequate to assess their technical feasibility (i.e., EPA has not
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8 Summary and Findings
generally included alternatives that are experimental, unproven, or have not seen at least pilot-scale
application).
Cost and Economic Impacts
Section 8002(p) of RCRA requires EPA to analyze "alternatives to current disposal methods" for solid
wastes generated from the extraction, beneficiation, and processing of ores and minerals. EPA is also required
to analyze "the costs of such alternatives." Section 6 of each commodity-specific chapter (in Volume II)
discusses the costs and associated economic impacts of alternative waste management practices. The analysis
of costs and impacts is limited in scope to those waste streams that exhibit one or more characteristics of
hazardous waste and/or exhibit documented damage or potential risk.
The focus of the analysis is on the comparative operational and financial consequences of regulating
these materials under various regulatory schemes. First, cost and impacts are calculated for regulation of these
wastes under full Subtitle C of RCRA. Two less stringent regulatory scenarios are also considered, one of
which reflects the potential for relaxed hazardous waste management controls found at §3004(x) of RCRA
("Subtitle C-Minus"), while the other is a hypothetical Subtitle D program designed to specifically address
mineral processing wastes ("Subtitle D-Plus").
The incremental costs associated with alternative regulatory options are compared to several financial
indicators at the facility level in order to determine the relative magnitude of potential impacts. In addition,
the Agency has evaluated market conditions facing each affected facility and sector to assess the extent to
which facilities potentially facing compliance costs would be able to pass through these costs to various
product markets or force reductions in the cost of inputs (e.g., ore concentrate, labor).
In conducting this cost analysis, EPA has assumed, in most cases, that waste streams are potentially
hazardous at only the individual facilities for which data submitted by industry or EPA sampling data indicate
that the waste exhibits one or more of the four characteristics of a hazardous waste, as defined by 40 CFR Part
261 Subpart C. When wastes do exhibit a hazardous waste characteristic t is assumed that the waste(s) would
be regulated as hazardous waste were it not for the exclusion provided bv RCRA §3001(b)(3)(A)(ii), and the
wastes are examined in the cost analysis accordingly.
3.3 Decision Rationale
EPA has developed two alternative approaches to analyze the information presented in this report
regarding each of the 20 special wastes from mineral processing. Both approaches share a three-step process
that the Agency used to evaluate the RCRA §8002(p) study factors by first assessing the need for additional
regulatory controls (or absence thereof), then evaluating the options for appropriate requirements that could
be applied to each individual waste stream for which additional controls might be in order, and, finally,
estimate the associated costs and impacts. The second approach is distinguished from the first by the addition
of a fourth step in which the Agency considered additional factors based on broader Agency goals and
objectives. By applying this decision-making framework, consistent decisions regarding the need for additional
regulatory controls for each of the 20 special study wastes were achieved.
In applying the decision criteria, EPA believes that the factors that are most important in establishing
the regulatory status of the special wastes should be given major emphasis. Therefore, potential risks posed
and documented damages caused by the wastes, the need for additional regulations, the costs and impacts that
would be associated with more stringent regulatory controls, and overall Agency objectives are the focus of
the four steps in the analysis process. The reason for this is that in the absence of potential risk and/or
documented damages, there is no need for hazardous waste regulation under RCRA Subtitle C (the key issue
in question); if greater regulatory controls are needed because of significant potential or documented danger,
the costs and impacts of regulatory controls are the critical factors in determining whether a given alternative
would lead to the desired outcome (adequate protection of human health and the environment and continued
operation of the affected industries).
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Summary and Findings 5
Waste Characteristics, Generation, and Current Management Practices
To characterize the generation and management of each of the 20 special mineral processing wastes,
EPA had to identify the facilities that generate the wastes, the production processes used and the products
produced, the quantity and characteristics of the wastes generated, and the practices that are employed to
manage them.
The identification of the facilities that generate one or more of the 20 special wastes was based upon
prior EPA work, supplemented extensively by information provided by Commodity Specialists with the U.S
Bureau of Mines. The operators of these facilities then were sent a survey questionnaire (SWMPF Surve\ j
requesting information on waste generation and management. Survey responses allowed EPA to finalize its
list of the active facilities in the mineral processing sectors of concern, and serve as the primary basis of EPA's
understanding of the current management practices that are applied to special wastes from mineral processing
operations.
Information submitted by industry in response to the SWMPF Survey was supplemented with and
critically evaluated against data obtained from published sources, information collected as part of the damage
case development process, and EPA observations made during waste sampling and other site visits. The
descriptions of waste management practices provided in this report reflect EPA's synthesis of the information
obtained during all of these information collection activities.
Potential and Documented Danger to Human Health and the Environment
Potential Danger to Human Health and the Environment
EPA conducted a facility-specific analysis of the risks associated with each of the 20 mineral
processing wastes. The Agency collected information on the major factors that influence risks from the
management of the special wastes at each of the 91 facilities that ge ^rate the wastes, and analyzed this
information to develop conclusions on the potential for toxic constituerts to be released from the waste and
cause human health and environmental impacts. In a limited number of cases, EPA also conducted
quantitative risk modeling to estimate potential danger to human health and the environment.
EPA employed a three step approach in this risk assessment, using each step as a means of narrowing
the scope of the analysis to those wastes and facilities that pose the greatest potential risk. First, the Agency
assessed the intrinsic hazard of the wastes by comparing the concentrations of toxic constituents in the wastes
and in leachate from the wastes to screening criteria.5 This step was used to determine which, if any,
constituents of the special wastes may pose risks to human health and the environment based on reasonable,
but conservative exposure assumptions. Second, EPA assessed the potential for toxic constituents from the
subject wastes to cause damage at the 91 facilities by evaluating the practices currently used to manage the
wastes and the environmental settings in which the wastes are managed. Using facility-specific information
about special waste management and environmental setting, EPA then evaluated the potential for toxic or
radioactive constituents to be released from the specific waste management units and to migrate to potential
exposure points. Finally, for waste stream/environmental settings combinations at which risk potential
appeared to be the greatest, EPA performed quantitative modeling to estimate the human health and
environmental risks associated with existing waste management practices.
In all steps of the analysis, EPA focused on human health and environmental risks associated with
chronic exposure to potential releases of waste constituents to ground water, surface water, and air. When
possible, however, the Agency did evaluate the potential for large episodic releases of waste constituents (e.g.,
from storm or flood events) to endanger human health or the environment. To analyze risks to human health.
5The focus of the screening criteria is on icon city and radioactivity, m addition to a simple determination of corrosivity. EPA has
sufficient knowledge of the characteristics of the 20 special mineral processing wastes to conclude that none are ignitable or reactive.
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Summary and Findings
the Agency evaluated the cancer and noncancer risks to maximally exposed individuals at each site. To analyze
environmental risks, the Agency evaluated the potential for contaminants to migrate from the waste and
adversely affect aquatic organisms. In addition to risks to human health and aquatic life, EPA also evaluated
the potential for existing waste management practices to reduce the quality of water and air resources by
considering the potential for air and water contamination, irrespective of the potential for humans or
ecological receptors to be exposed to the contamination.
Documented Cases of Danger to Human Health or the Environment
Section 8002(p)(4) of RCRA requires that EPA's study of mineral processing wastes examine
"documented cases in which danger to human health or the environment has been proved." In order to address
this requirement, EPA defined danger to human health and the environment in the following way. First,
danger to human health includes both acute and chronic effects associated with management of mineral
processing wastes. Second, danger to the environment includes: (1) impairment of natural resources; (2)
ecological effects resulting in impairment of the structure or function of natural ecosystems and habitats; and
(3) effects on wildlife resulting in impairment to terrestrial or aquatic species.
The statutory requirement is that EPA examine "proven" cases of danger to human health or the
environment. As a result, EPA developed a "test of proof to be used for determining if documentation
available on a case proves that danger/damage has occurred. This "test of proof contains three separate tests;
a case that satisfies one or more of these tests is considered "proven." The tests are as follows:
1. Scientific investigation: Damages are found to exist as pan of the findings of a
scientific study. Such studies include both extensive formal investigations supporting
litigation or a State enforcement action and the results of technical tests (such as
monitoring of wells). Scientific studies must demonstrate that damages are significant
in terms of impacts on human health or the environment. For example, information
on contamination of a drinking water aquifer must indica : that contamination levels
exceed drinking water standards.
2. Administrative ruling: Damages are found to exist through a formal administrative
ruling, such as the conclusions of a site report by a field inspector, or through
existence of an enforcement action that cited specific health or environmental
damages.
3. Court decision: Damages are found to exist through the ruling of a court or through
an out-of-court settlement.
EPA has taken care in the course of preparing this evaluation to report only damages that are
relevant to the decisions that will be based upon the Report to Congress (i.e., whether regulation of each of
the special wastes from mineral processing under Subtitle C is appropriate). Consequently, the damage cases
reported here are believed to be attributable (at least in part) to the special study wastes, and are believed to
have resulted from management practices that are currently employed by active facilities in the commodity
sectors of interest
Existing Federal and State Waste Management Controls
In accordance with the suggestion in RCRA §8002(p), EPA has also examined other applicable federal
and state waste management controls in an effort to minimize duplication.
Federal Controls
EPA's objective in this analysis was to identify and evaluate the existing regulatory controls over the
management of special mineral processing wastes that have been promulgated by agencies of the federal
government, focusing on programs and requirements established by EPA. This evaluation was performed for
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Summary and Findings 3
Phosphoric acid
phosphogypsum
process wastewater
Titanium tetrachloride
chloride process waste solids
slag from primary processing
All other solid wastes from the processing of ores and minerals were removed from the Mining Waste
Exclusion as of the effective date of the September 1, 1989 or January 23, 1990 final rules (March 1, 1990, or
July 23, 1990 in non-authorized states), and are subject to regulation as hazardous wastes if they exhibit one
or more characteristics of hazardous waste or are otherwise listed as hazardous waste.4
A summary of the important events in the rulemaking process and of the criteria that have been
developed by the Agency to identify the 20 special wastes from mineral processing operations is presented in
Appendix A to the report (contained in Volume III).
Following receipt and analysis of public comment on this report, the Agency will issue the regulatory
determination required by RCRA §3001(b)(3)(C) that will either subject one or more of the 20 special mineral
processing wastes to regulation under Subtitle C as hazardous wastes or conclude that such regulation is
unwarranted. Wastes for which the Exclusion is retained will continue to be subject to regulation under
RCRA Subtitle D as solid wastes. Our assessment of risk in this report has been based on a conservative set
of risk assumptions. If additional regulation of these wastes is determined to be necessary, we would make
such a determination with this in mind.
2.0 RCRA §8002(p) Study Factors
This report addresses the following eight study factors require'. by §8002(p) of RCRA for the 20
mineral processing wastes listed above:
1. The sources and volumes of such materials generated per year;
2. Present disposal and utilization practices;
3. Potential danger to human health and the environment from the disposal and
reuse of such materials;
4. Documented cases in which danger to human health or the environment has
been proved;
5. Alternatives to current disposal methods;
6. The costs of such alternatives;
7. The impacts of these alternatives on the use of phosphate rock, uranium ore,
and other natural resources; and
4 Because the requirements of the September 1,1989 and January 23,1990 final rules were not imposed pursuant to the
Hazardous and Solid Waste Amendments of 1984, they will not be effective in RCRA authorized states until the state program
amendments are effective. Thus, the rules are effective on March 1,1990 and July 23,1990 (for the September 1,1989 and January
23, 1990 rules, respectively) only in those states that do not have flnal authorization to operate their own hazardous waste programs in
lieu of the Federal program. In authorized states, the rules are not applicable until the state revises its program to adopt equivalent
requirements under state law and receives authorization for these new requirements. (Of course, the requirements will be applicable
as state law if the state law is effective prior to authorization.) States that have final authorization must revise their programs to adopt
equivalent standards regulating non-exempt mineral processing wastes that exhibit hazardous characteristics as hazardous by July 1,
1991 if regulatory changes only are necessary, or by July 1, 1992 if statutory changes are necessary. Once EPA approves the revision.
the slate requirements become RCRA Subtitle C requirements in that state.
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Summary and Findings
8. The current and potential utilization of such materials.
The Agency's approach in preparing this report was to combine certain study factors for purposes of
analysis and exposition. The resulting discussions, which are found in individual chapters (in Volume II)
addressing each of the mineral commodity sectors, are organized in seven sections. The first section provides
a brief overview of the industry, including the types of production processes used and the number and location
of operating facilities that generate one or more mineral processing special wastes. The second section
summarizes information on special waste characteristics, generation, and current management practices (study
factors 1 and 2), while the third section provides a discussion of potential for and documented cases of danger
to human health or the environment (study factors 3 and 4). The fourth section (as suggested by § 8002(p)
of RCRA, independent of the eight study factors) summarizes applicable federal and state regulatory controls.
The fifth section discusses alternative waste management practices and potential utilization of the wastes (study
factors 5 and 8), while the sixth section discusses costs and impacts of alternative practices (study factors 6 and
7). The seventh and final section summarizes and analyzes the findings of EPA's evaluation of the above study
factors.
3.0 Methods, Information Sources and Decision Rationale
In preparing this report, EPA has developed facility-specific data and analytical methods that reflect
the complexity of the issues that are addressed herein. The facilities that generate the special study wastes vary
considerably in the types of production operations and waste management techniques that they employ.
Moreover, to examine in detail the broad array of study factors mandated by RCRA §8002(p), EPA had to
develop approaches and methods that were sufficiently sophisticated to take into account the special nature
of high volume mineral processing wastes. This section briefly outlines the data sources, methods, and decision
rationale that the Agency employed to respond to the study factors.
3.1 EPA Data Collection Activities
EPA's Office of Solid Waste conducted a number of data collection activities to supplement and
update previous work. The focus of most of these efforts was site-specific. As a consequence, EPA has been
able to compile detailed facility- and sector-specific data bases, which the Agency has used extensively to
prepare this report as well as a series of rulemakings which, as discussed above, have clarified the boundaries
of the Mining Waste Exclusion as it applies to mineral processing wastes. The major information-gathering
initiatives are as follows:
• Review of Public Comments
1989 National Survey of Solid Wastes from Mineral Processing Facilities (SWMPF
Survey)
1989 EPA Mineral Processing Waste Sampling and Analysis
• EPA Damage Case Collection
EPA Site Visits
RCRA §3007 Waste Characteristics Data Requests
These activities are described in more detail in Chapter 2 of Volume n, with additional discussion and/or
examples provided in Appendix B, which is contained in Volume III.
3.2 Analytical Approach and Methods
This section summarizes EPAs approach for addressing each of the study factors.
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Summary and Findings
1.0 Introduction
In October, 1980, the Resource Conservation and Recovery Act (RCRA) was amended by addme
§3001(b)(3)(A)(ii) to exclude "solid waste from the extraction, beneficiation, and processing of ores and
minerals" from regulation as hazardous waste under Subtitle C of RCRA, pending completion of a study and
a Report to Congress required by §8002(0 and (P) and a determination by the EPA Administrator either to
promulgate regulations under Subtitle C or that such regulations are unwarranted (as required by
§3001(b)(3)(C)). EPA modified its hazardous waste regulations in November 1980 to reflect this "Mining
Waste Exclusion," and issued a preliminary, and quite broad, interpretation of the scope of its coverage. In
particular, EPA interpreted the exclusion to include "solid waste from the exploration, mining, milling,
smelting and refining of ores and minerals" (45 FR 76618, November 19, 1980).
In 1984, EPA was sued for failing to submit the Report to Congress and make the required regulatory
determination by the statutory deadline (Concerned Citizens ofAdamstown v. EPA No. 84-3041, D.D.C., August
21, 1985). In responding to this lawsuit, the Agency explained that it planned to propose a narrower
interpretation of the scope of the Mining Waste Exclusion, so that it would encompass fewer wastes, and
proposed to the Court two schedules: one for completing the §8002 studies of extraction and beneficiation
wastes and submitting the Report to Congress for these wastes, and one for proposing and promulgating a
reinterpretation for mineral processing wastes. In so doing, the Agency, in effect, split the wastes that might
be eligible for exclusion from regulation into two groups: mining (mineral extraction and beneficiation) wastes,
and mineral processing wastes. The Court agreed to this approach and established a schedule for the two
tasks.
On December 31,1985, EPA published the required Report to C ngress on solid wastes from mineral
extraction and beneficiation,1 and on July 3, 1986 (51 FR 24496) publb ^ed a determination that regulation
of such wastes under Subtitle C of RCRA was not warranted. Since the determination was made, the Agency
has been developing a tailored regulatory approach for these materials under the auspices of RCRA
Subtitle D. In May, 1988, EPA issued a staff-level approach for regulating mining wastes (referred to as
"Strawman") for public comment. More recently, the Agency issued a revised staff-level approach ("Strawman
II") that incorporates comments from and responds to issues raised by the states, environmental groups, and
the regulated community. The Agency is working to develop a formal proposal of a regulatory program for
mineral extraction and beneficiation wastes.2
In keeping with its Court-ordered directive to reinterpret the Mining Waste Exclusion for mineral
processing wastes, in October, 1985, EPA proposed to narrow the scope of the Exclusion for mineral
processing wastes to include only a few specific waste streams. However, the Agency did not specify the
criteria that it used to identify these materials, or to distinguish them from other wastes that were not eligible
for the exclusion. In response to this proposal, many companies and industry organizations "nominated" wastes
that they believed were eligible for the regulatory exemption. Faced with an inability at that time to articulate
1 U. S. Environmental Protection Agency, 1985. Report to Congress on Wastes from the Extraction and Beneficiation of Metallic
Ores. Phosphate Rock. Asbestos, Overburden from Uranium Mining, and Oil Shale. EPA/530-SW-85-033, Washington, D.C.
Available from the U.S. Department of Commerce, National Technical Information Service, Springfield, VA. NTIS Document No
PB88-162631.
• The Agency has recently requested comments on Strawman II, including the appropriate scope of the program (i.e., which wastes
should be covered).
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Summary and Findings
criteria that could be used to distinguish exempt from non-exempt wastes and the approaching Court-ordered
deadline for final action, EPA withdrew its proposal on October 9, 1986.
In response to this action, the Agency was sued again. In July, 1988, the court in Environmental
Defense Fund v. EPA, 852 F.2d 1316 (D. C. Cir. 1988), cert, denied, 109 S. Ct. 1120 (1989) ordered EPA to
reinterpret the scope of the Exclusion for mineral processing wastes according to a new schedule. In
particular, EPA was directed by the court to restrict the scope of the Exclusion as it applied to mineral
processing wastes to include only "large volume, low hazard" wastes. In a series of rulemaking notices, EPA
has, during the past two years, established the boundaries of the Mining Waste Exclusion for mineral
processing wastes, and has articulated the criteria that were used to define "mineral processing" and to evaluate
whether individual wastes are large volume and low hazard and, thus, eligible for the temporary exclusion
provided by RCRA §3001(b)(3)(A)(ii). This rulemaking process was completed with the publication of a final
rule on January 23, 1990 (55 FR 2322).3 With the completion of these notices, the Agency established that
the temporary exemption from Subtitle C requirements established by the Exclusion for mineral processing
wastes and, therefore, the scope of this report, is limited to 20 mineral processing wastes generated by 91
facilities located in 29 states, representing 12 mineral commodity sectors. In particular, this report covers the
following wastes:
• Alumina
red and brown muds from bauxite refining
• Chromium (Sodium chromate/dichromatel
treated residue from roasting/leaching of chrome ore
• Coal gas
gasifier ash from coal gasification
process wastewater from coal gasification
• Copper
slag from primary processing
calcium sulfate wastewater treatment plant sludge rom primary
processing
slag tailings from primary processing
• Elemental phosphorus
slag from primary production
• Ferrous metals firon and carbon steeH
iron blast furnace air pollution control dust/sludge
iron blast furnace slag
basic oxygen furnace and open hearth furnace air pollution control
dust/sludge
basic oxygen furnace and open hearth furnace slag
• Hydrofluoric acid
fluorogypsum
process wastewater
• Lead
slag from primary processing
• Magnesium
process wastewater from primary magnesium processing by the anhydrous process
3 This rulemaking process also included publication of a proposed rule on October 20, 1988 (53 FR 41288), a proposed rule on
Apnl 17, 1989 (54 FR 15316), a final rule on September 1, 1989 ( 54 FR 36592), and a proposed rule on September 25, 1989 (54 FR
39298).
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Table of Contents
Page
1.0 Introduction 1
2.0 RCRA §8002(p) Study Factors 3
3.0 Methods, Information Sources and Decision Rationale 4
3.1 EPA Data Collection Activities 4
3.2 Analytical Approach and Methods 4
3.3 Decision Rationale 8
4.0 Findings 11
4.1 Application of the RCRA §8002(p) Study Factors: Approach 1 11
4.2 Application of the RCRA §8002(p) Study Factors and ^ ditional
Considerations: Approach 2 16
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Chapter 3
Alumina Production
The domestic alumina production (bauxite refining) industry consists of five facilities that, as of
September 1989, were active and reported generating a special waste from mineral processing: red and brown
muds from bauxite refining. The information included in this chapter is provided in additional detail in the
supporting public docket for this report.
3.1 Industry Overview
Bauxite refineries produce alumina (A12O3), which is used primarily as a feedstock for the aluminum
reduction industry. Four of the facilities are operated by major aluminum producers, two by Alcoa, and one
each by Reynolds and Kaiser. The fifth facility is operated by Onnet, which produced only about 1 percent
of the total reported 1988 alumina production. Kaiser Aluminum is ultimately owned by MAXXAM Inc. of
Los Angeles;1 Onnet, owned by Ohio River Associates in 1988, is currently owned by Oralco Management
Services Inc.
The dates of initial operation for these five facilities range from 1952 to 1959, with the individual
plants having an average age of approximately 33 years. All of the facilities have undergone modernization,
with the first in 1965 and the latest in 1986.2 The locations and ore sources of the five facilities are presented
in Exhibit 3-1. Total annual production capacity for the domestic bauxite refining industry, as reported by the
facilities, is approximately 4,900,000 metric tons. For the five facilities, the 1988 average capacity utilization
rate was 83.5 percent. Excluding the Onnet facility with an 8.9 percent 1988 annual capacity utilization rate,
the rate for the sector is 91.7 percent The total reported 1988 production of alumina was 4,086,000 metric
tons.3
Strong demand for primary aluminum and elevated aluminum prices have led to steadily increasing
consumption of domestic and imported bauxite and continued increases in alumina production in the U.S.
since 1986.4 In order to meet the growing demand for alumina, bauxite refineries have averaged over 90
percent capacity utilization over the past two years. Recently, expansion in bauxite refining capacity has been
focused outside of the U.S. It is likely that this trend will continue in the future, with major capacity additions
likely to occur in Canada and the Middle East.5 In addition, new plants using new technology may have to
be built to produce alumina from the numerous non-bauxitic materials, including clay, coal waste, and oil
shales, that are good potential sources of alumina.6 Development of such technology would reduce U.S.
dependence on bauxite imports, which comprised approximately 95 percent of the total 1989 U.S. consumption
of bauxite.7
1 MAXXAM Inc. is the parent of MAXXAM Group, Inc., which owns Kaiser Tech Limited, the immediate owner of Kaiser Aluminum
and Chemical Corporation.
2 Alcoa, Kaiser, Onnet, and Reynolds, 1989. Company responses to "National Survey of Solid Wastes from Mineral Processing
Facilities," 1989.
3 Ibid.
4 Luke H. Baumgardner, U.S. Bureau of Mines, "Bauble," Mineral Commodity Summaries. 1989 Ed., p. 23.
5 John W. Moberty, "Aluminum: Capacity Rise Stabilizes Price; 121st Annual Survey and Outlook," EAMJ. March 1990, p. 41.
* Patricia A Plunkert, U.S. Bureau of Mines, "Bauxite," Mineral Commodity Summaries. 1990 Ed., p. 29.
7 Ibid., p. 28.
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3-2 Chapter 3: Alumina Production
Exhibit 3-1
Bauxite Refineries^
Owner
ALCOA
ALCOA
Kaiser
ORMET
Reynolds
Location
Bauxite, AR*>
Point Comfort, TX
Gramercy, LA
Burnside, LA
Gregory, TX
Ore Source (1982)
U.S. (Bauxite, AR)^
(Confidential)
Jamaica'4
Sierra Leone, Brazil, Guyana'"
Auslrailia, Jamaica, Brazil, Guinea"'
(a) According to BOM sources, VIALCO, an affiliate of Oralco Management Services Inc., plans to restart operation of its
Alumina plant at St. Croix, U.S. Virgin Islands.
(b) According to BOM sources, Alcoa announced the permanent closure of its Bauxite, AR, plants on June 7,1990.
(c) Environmental Protection Agency, 1984. Overview of Solid Waste Generation. Management, and Chemical Characteristics
in the Bauxite Refining and Primary Aluminum Industry. Prepared by Radian Corporation lor U.S. EPA, Office of Solid
Waste, Washington, D.C., November 1984.
(d) Kaiser, 1988. Personal communication with Kaiser representatives.
(e) Bureau of Mines commodity specialist, June 27, 1990.
The production of alumina from bauxite ore generally follows five steps, as shown in Exhibit 3-2.8
First, the bauxite ore is crushed and screened, and then mixed with a caustic alkaline solution (NaOH). The
slurried ore is then routed to digesters, where the aluminum is heated and solubilized as sodium aluminate
(Na2Al2O3). In the third step, the solution is cooled (from nearly 500°F to about 200°F) and purified. Sand
(particles above 100 microns) is removed in a settling tank or cyclone am ent to disposal. Iron oxide, silica,
and other undigested portions of the ore (i.e., the special waste, know collectively as red mud) are also
removed in settling, thickening, and filtration units, and sent to treatment and disposal units. The fourth
refining step is the precipitation of the cooled and purified aluminum hydroxide using sodium hydroxide seed
crystals. The precipitate is filtered, then concentrated by evaporation; the resulting intermediate product is
a hydroxide filter cake. The fifth and final step is the calcination of the hydroxide filter cake to produce
anhydrous alumina. If hydrate is the desired final product, the hydroxide filter cake may be dried at lower
temperatures than those employed for calcining.
3.2 Waste Characteristics, Generation, and Current Management Practices
Red and brown muds are precipitated from a caustic suspension of sodium aluminate in a slurry and
routed to large on-site surface impoundments known as red and brown mud lakes. In these lakes, the red and
brown muds settle to the bottom and the water is removed, treated, and either discharged or reused. The
muds are not removed, but are accumulated and disposed in place. The muds dry to a solid with a very fine
particle size (sometimes less than 1 jun).
8 Environmental Protection Agency, 1984. Overview of Solid Waste Generation. Management, and Chemical Characteristics in the
Bauxite Refining and Primary Aluminum Industry. Prepared by Radian Corporation for U.S. EPA, Office of Solid Waste, Washington,
D.C., November 1984.
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Chapter 3: Alumina Production 3-3
Exhibit 3-2
Alumina Production
PROCESS
Crushing and
Blending
(Beneficiation)
-»
Digestion
+
Filtration
->
Precipitation
->
Calcination
SPECIAL WASTE
MANAGEMENT
Legend:
Production Operation
Special Waste
( )
Waste Management Unit
Red muds from bauxite refining are generated at four facilities9. The fifth facility, Alcoa in Bauxite,
Arkansas, generates a residual that is different in color and is comm ily called brown mud. The only
difference in the operations generating the two varieties of mud is that red muds at Alcoa/Bauxite are sintered
and leached to recover additional sodium aluminate, which changes the color of the material but does not
substantially change the chemical characteristics of the waste. Therefore, for purposes of this report, the waste
generated at all five facilities, including the brown muds, will be referred to as red muds.
Red muds contain significant amounts of iron (20 to SO percent), aluminum (20 to 30 percent), silicon
(10 to 20 percent), calcium (10 to 30 percent), and sodium (10 to 20 percent). Red muds may also contain
trace amounts of elements such as barium, boron, cadmium, chromium, cobalt, gallium, vanadium, scandium,
and lead, as well as radionuclides. The types and concentrations of minerals present in the muds depend on
the composition of the ore and the operating conditions in the digesters.
Using available data on the composition of red muds, EPA evaluated whether this waste exhibits any
of the four hazardous waste characteristics: corrosiviry, reactivity, ignitability, and extraction procedure (EP)
toxicity. Data are available on the concentrations of all eight inorganic EP constituents in four samples of red
muds from three of the five facilities of interest. Based on available information and professional judgment,
EPA does not believe that red muds exhibit any of the characteristics of hazardous waste. In fact, the
concentrations of all EP constituents (except selenium) in the leachate are at least two orders of magnitude
below the EP regulatory levels; the maximum concentration of selenium in the EP extract is approximately
0.3 times the EP regulatory level.
9 In the April 17,1989 proposal to reinterpret the scope of the mining waste exclusion, EPA indicated that it "considers pisolites to
be a component of red muds" (54 FR 15335). In the Gnal rule (see 54 FR 36592, September 1,1989), however, the scope of beneficiation
activities was revised such that pisolites are considered a waste from beneficiation rather than processing. Consequently, pisolites are not
within the scope of this report.
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3-4 Chapter 3: Alumina Production
Non-confidential waste generation rate data were reported for red muds by all five bauxite refining
facilities. The aggregate industry-wide generation of red mud wastes by the five facilities was approximately
2.8 million metric tons in 1988, yielding a facility average of nearly 564,000 metric tons per year. Reported
annual generation rates ranged from 26,000 to 1.2 million metric tons per facility, though the faciliu
generating the least waste, Onnet/Burnside, produced very little alumina, accounting for only about 1 percent
of domestic production. The next lowest reported annual generation rate was 190,000 metric tons. The sector-
wide waste-to-product ratio was 0.69 in 1988; waste-to-product ratios for individual facilities ranged from 0.40
to 1.05.
The impoundments that receive the muds typically have a surface area of between 44.6 and 105.3
hectares (110 and 260 acres), although one impoundment is 10.1 hectares and another is almost 1,300 hectares.
The depth of the impoundments range from 1 to 16 meters (3 to 52 feet), with an impoundment average of
7 meters. As of 1988, the quantity of muds accumulated on-site at the 5 facilities ranged from 500,000 to 22
million metric tons per facility, with an average of 9.7 million metric tons per facility.
3.3 Potential and Documented Danger to Human Health and the Environment
This section addresses two of the study factors required by §8002(p) of RCRA: (1) potential danger
(i.e., risk) to human health and the environment: and (2) documented cases in which danger to human health
or the environment has been proved. Overall findings regarding the hazards associated with red muds are
provided after these two study factors are discussed.
3.3.1 Risks Associated with Red Muds
Any potential danger to human health and the environment from red muds depends on the presence
of toxic constituents in the muds that may pose a risk and the potential for exposure to these constituents.
Constituents of Potential Concern
EPA identified chemical constituents in red muds that may pose a risk by collecting data on the
composition of the waste and evaluating the intrinsic hazard of the mud's chemical constituents.
Data on Red Mud Compotft/on
Data on the composition of red muds are available from industry responses to a RCRA §3007 request
in 1989, a 1985 sampling and analysis effort by EPAs Office of Solid Uaste (OSW),10 and a 1982 study by
EPAs Office of Radiation Programs (ORP).11 These data identify the concentrations of 13 metals, 7
radionuclides, and 5 anions (fluoride, phosphate, chloride, nitrate, and sulfate) in the mud solids and/or
leachate from all 5 facilities that currently generate the muds. Data are onty available from EP (not SPLP)
leach tests.
Although the data from most of these sources and facilities are generally consistent, there is
considerable variability for several constituents. Specifically, reported concentrations of arsenic, chromium,
copper, iron, manganese, selenium, and zinc in the mud solids vary by an order of magnitude across facilities,
with the concentrations usually being lowest at one facility (which requested that its concentration data be
treated as confidential). Similarly, reported concentrations of chromium, fluoride, selenium, and chloride in
the mud leachate also vary by an order of magnitude across facilities.
10 Environmental Protection Agency, 1985. Overview of Solid Waste Generation. Management and Chemical Characteristics in the
Bauxite Refining and Primary Aluminum Reduction Industries. Office of Solid Waste, p. B-l and B-2.
11 Environmental Protection Agency, 1982. Emissions of Naturally Occurring Radioactivity from Aluminum and Copper Facilities,
Office of Radiation Programs, Las Vegas Facility, NV, p. 8.
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Chapter 3: Alumina Production 3-5
As noted above in Section 3.2, the available data indicate that red muds do not exhibit any of the four
characteristics of hazardous waste. Nevertheless, EPA further evaluated the potential for red muds to pose
a danger to human health or the environment, as described below.
Process for Identifying Constituents of Potential Concern
As discussed in detail in Section 2.2.2, the Agency evaluated the red muds data to determine if the
mud or mud leachate contain any constituents that could pose an intrinsic hazard, and to narrow the focus
of the risk assessment. The Agency performed this evaluation by first comparing the concentrations of each
constituent to screening criteria and then by evaluating the environmental persistence and mobility of any
constituents present in concentrations that exceed the criteria. These screening criteria were developed using
assumed scenarios that are likely to overestimate the extent to which red mud constituents are released to the
environment and migrate to possible exposure points. As a result, this process identifies and eliminates from
further consideration those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic organisms, and water resources (see Exhibit 2-3). Given the conservative (i.e., overly
protective) nature of these screening criteria, contaminant concentrations in excess of the criteria should not,
in isolation, be interpreted as proof of the hazard. Instead, exceedances of the criteria indicate the need to
evaluate the potential hazards of the waste in greater detail.
Identified Constituents of Potential Concern
Of the 25 constituents analyzed in mud solids, only 3 were determined to be present in the muds in
concentrations that exceed the screening criteria.
• Arsenic concentrations in one out of two samples collected from two facilities exceed
the chronic ingestion and inhalation screening criteria, by a factor of four. Exceedance
of the ingestion criterion suggests that arsenic could pose ± cancer risk of greater than
10"5 if the muds are incidentally ingested on a routine baxs (which could only occur if
access to mud impoundments after closure is not restricted and people come into direct
contact with the dried muds). Exceedance of the inhalation criterion suggests that, if
dust from the muds is blown into the air in a concentration that equals the maximum
allowable limit (the National Ambient Air Quality Standard) for paniculate matter,
chronic inhalation of arsenic could pose a cancer risk greater than 10'5. As discussed
in the next section, such large exposures to windblown dust are generally not expected.
• Chromium concentrations in both samples (one each from two facilities) exceed the
chronic inhalation screening criterion by as much as a factor of 22. This suggests that
if dust from the muds is blown into the air in a concentration that equals the National
Ambient Air Quality Standard for paniculate matter, chronic inhalation of chromium
could cause a cancer risk exceeding 10"5. Again, EPA generally does not expect such
large exposures, as explained in the next section.
• Radium-226 concentrations in the mud solids exceed the radiation protection screening
criterion by a factor of 13. This suggests that red muds could pose a slight radiation
risk if they are used in an unrestricted manner (e.g., direct radiation and radon
exposures if people were allowed to build homes on the closed impoundment areas).
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3-6 Chapter 3: Alumina Production
In addition to these three constituents, the alkaline nature (Le., high pH) of the muds will limit plant
growth on the dried, closed impoundments. Data from EPA's Office of Wfcter show that the supernatant
removed from the red mud impoundments has a pH of roughly 11.6.12 The residual alkali content of the
muds that are left in the impoundments makes it difficult to use these impoundment areas for agricultural
production.13'
Of the 18 constituents analyzed in leachate from red muds, only two constituents are present in
concentrations that exceed the initial screening criteria. Arsenic concentrations in the leachate exceed the
health screening criterion in two out of four samples (from two out of three facilities). The maximum
recorded arsenic concentration exceeded the screening criterion by only a factor of three. This suggests that,
if the leachate is released to ground water and diluted by only a factor of 10, the resulting concentration of
arsenic may pose a cancer risk exceeding 10~5 if ingested. The concentration of selenium in the leachate
exceeds the water resource damage criterion in one out of four samples (from one out of three facilities). The
one high selenium concentration exceeds the criterion by only a factor of three. This suggests that, if the
leachate is released to ground water and diluted by a factor of 10 or less, the downgradient concentrations of
selenium may exceed the drinking water maximum contaminant level (MCL) for that constituent. While these
concentrations of arsenic and selenium exceed the conservative screening criteria, they do not exceed the EP
toxicity regulatory levels.
These exceedances of the screening criteria, by themselves, do not demonstrate that the muds pose
a significant risk, but rather indicate that the muds could pose a risk under a very conservative, hypothetical
set of release, transport, and exposure conditions. To determine the potential for the muds to cause significant
impacts, EPA proceeded to the next step of the risk assessment to analyze the actual conditions that exist at
the facilities that generate and manage the waste.
Release, Transport, and Exposure Potential
This analysis considers the baseline hazards of red muds as they a.. managed in impoundments at the
five bauxite refining facilities. It does not assess the hazards of off-site u^e or disposal of the muds because
the muds are currently managed only on-site and are not likely to be managed off-site in the near future. In
addition, the following analysis does not consider the risks associated with variations in waste management
practices or potentially exposed populations in the future because of a lack of data on future conditions.
Alternative practices for the management of the muds are discussed in Section 3.5.
Ground-Water Re/ease, Transport, and Exposure Potent/a/
During the operating phase of the red mud lakes, the muds are usually submerged beneath a liquid
that can serve as a leaching medium, potentially transporting contaminants to underlying ground water. After
the lakes are closed, the liquids are evaporated or removed, and the potential for leaching becomes highly
dependent on the extent to which precipitation infiltrates through the mud and into the ground. Based on
the leach test data analyzed above, arsenic and selenium are the constituents in red muds that are most likely
to leach from the muds in concentrations that exceed the screening criteria. Both arsenic and selenium are
persistent and relatively mobile in ground water, and therefore are capable of migrating readily if released.
The potential for leachate from the muds to be released to ground water and cause impacts through
that pathway varies according to site-specific conditions, as summarized below:
• At the Burnside, LA facility, the mud impoundment is underlain by recompacted local
clay. Ground water is very shallow (only 2 meters below the land surface) and the base
12 Environmental Protection Agency, 1984. Development Document for Effluent Limitations Guidelines and Standards, Office of Water,
p. 56.
13 W A. Anderson and W.E. Haupin, 1978. Bauxite Refining. Aluminum Company of America, Kirk-Othmer Encyclopedia of Chemical
Technology, John Wiley and Sons, NY, p. 142.
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Chapter 3: Alumina Production 3-7
of the impoundment extends below the water table. The uppermost useable aquifer,
however, appears to be separated from the base of the impoundment by a distance of
roughly 30 meters. The nearest drinking water well appears to be located 90 meters
downgradient.
• The conditions at the Gramercy, LA facility are similar to those at the Burnside facility.
The only differences are that the impoundments at Gramercy are equipped with a
leachate collection system and the nearest drinking water well at Gramercy is farther
away, approximately 800 meters downgradient. As discussed in the damage case section
of this chapter, elevated concentrations of chloride have been detected in ground water
beneath the impoundments. However, the muds do not appear to be an important
contributor to this contamination because, based on the Agency's leach test analyses,
chloride is a minor constituent of the mud leachate (the maximum chloride con-
centration measured in the mud leachate was less than one-quarter of the conservative
screening criterion).
• The impoundment at the Bauxite, AR facility is underlain by in-situ clay and is
equipped with a leachate collection system and bentonite slurry walls. The base of the
impoundment appears to be separated from shallow ground water by 15 meters and the
uppermost useable aquifer by roughly 30 meters. The earth material separating the
impoundment from this useable aquifer is an igneous rock. Ground water in the area
of the site is used as a rural domestic water supply, and the nearest drinking water well
appears to be located 300 meters downgradient.
• At the Point Comfort, TX facility, the mud impoundment is underlain by in-situ clay,
but is not equipped with any other controls. Because the impoundment is 16 meters
deep and shallow ground water exists at a depth of 5 meters, the base of the im-
poundment extends below the water table. The uppermost useable aquifer, however, is
over 400 meters below the land surface. This deep aquifer is used as a municipal and
commercial/industrial water supply, and the nearest drink ag water well appears to be
located 1300 meters downgradient
• The impoundments at the Gregory, TX facility are underlain by in-situ clay. As for
most of the other sites, ground water is shallow and the base of the impoundment
extends below the water table. Neither the shallow ground water nor water at greater
depths, however, is used for water supply purposes, according to facility personnel.
In summary, laboratory leaching tests show that arsenic and selenium may leach from red muds in
concentrations that exceed the screening criteria. Concentrations of these and other constituents under field
conditions are, however, expected to be lower due to the alkaline nature of the waste. While the potential
for release of constituents to ground water is limited by some type of management controls employed at each
site, the bases of most impoundments do extend into the saturated zone and shallow ground-water
contamination is therefore possible. However, downward migration of this contamination to useable aquifers
is less likely, especially at the Bauxite and Point Comfort facilities, because of hydrogeological conditions.
Considering the low concentrations of contaminants in the leachate and the potential locations of drinking
water wells near these facilities, the concentrations of any contaminants that migrate into the deeper useable
aquifers at the five facilities is expected to be below levels of concern at existing downgradient exposure points.
Surface Water to/ease, Transport, and Exposure Potential
Constituents of potential concern in the red muds could, in theory, enter surface waters by migration
of leachate through ground water that discharges to surface water, or by direct overland (storm water) run-off
of dissolved or suspended constituents. As discussed above, only arsenic and selenium are expected to leach
from the muds in concentrations above the screening criteria, but even these concentrations are relatively low
and are likely to be diluted below levels of concern in all but very small streams. There were no constituents
deteaed in the mud leachate in concentrations that appeared to present a potential threat to aquatic
organisms; the arsenic and selenium concentrations are of possible concern from only a health risk standpoint.
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3-8 Chapter 3: Alumina Production
The high alkalinity of the muds, however, could result in leaching of alkaline water. If the receiving water is
not well-buffered, its pH could exceed levels that are protective of aquatic life. Alkaline water also can have
low resource value due to its corrosive properties.
The potential for mud contaminants to migrate into surface water and cause impacts is site-specific,
based on a number of factors as summarized below:
• At the Burnside facility in Louisiana, the red mud impoundment is equipped with run-
on/run-off controls to limit the direct overland flow of mud contaminants, but there are
no controls (e.g., liner, leachate collection system, or slurry wall) to prevent con-
taminants from seeping into surface water via ground water. The facility is only 15
meters from the Panama Canal which feeds into the Blind River. While the Blind River
has a moderate to large dilution capacity (the annual average flow is 302 mgd), the
Panama Canal's flow is small and cannot readily assimilate large contaminant loads. As
discussed in the damage case section of this report, excess process water that has
accumulated in red mud impoundments at the site during heavy rainfall events has been
discharged to the canal, resulting in high pH excursions. These discharges have
occurred only in emergency situations, and the pH excursions appear to be caused by
the supernatant liquid discharged from the impoundments, not the muds themselves.
• At the Point Comfort facility in Texas, the on-site impoundment is equipped with run-
on/run-off controls, but there are no controls to limit seepage of contaminants via
ground water. The facility is located only 15 meters from Lavaca Bay, which contains
saltwater. Water in the bay is not used for human consumption, but is withdrawn at a
point 270 meters downstream and used for livestock watering.
• On-site impoundments at the Gramercy Works in Louisiana are equipped with run-
on/run-off controls and a leachate collection system. The facility is located roughly 110
meters from the Blind River, which has a moderate to large dilution capacity (it is the
same river that is near the Burnside facility). Water is <• thdrawn from the river for
human consumption at a point 4,900 meters downstrean but water is not withdrawn
for any other uses within 24 km (15 miles).
• The impoundment at the facility in Gregory, Texas is equipped with run-on/run-off
controls. The facility is located roughly 60 meters from the Corpus Christi Bay, which
contains saltwater that is not used for drinking or any other consumptive use within 24
km (15 miles).
• At the facility in Bauxite, Arkansas, the impoundment is equipped with run-on/run-off
controls, a leachate collection system, and a bentonite slurry wall. The facility is located
about 300 meters from Hurricane Creek, which has a moderate dilution capacity (its
annual average flow is 80 mgd). Water is withdrawn from this creek for human
consumption at a point 7 km downstream, but water is not withdrawn for any other uses
within 24 km (15 miles).
In summary, the potential for direct overland flow of red mud contaminants to surface water is limited
at all five facilities by the use of run-on/run-off controls. Migration into surface water via ground-water
seepage, however, may occur at three facilities (at Burnside, Point Comfort, and Gregory) that are dose to
surface water bodies and do not employ any measures to control leachate migration. (The potential for
ground-water contamination to seep into surface water at the other facilities is smaller because of the use of
leachate migration controls and the greater distance to surface waters.) Because of the distances to drinking
water intakes, the moderate to high flows of the nearby water bodies, and the low concentrations of
contaminants expected in the mud leachate, any surface water contamination at the three facilities caused by
the muds would probably not pose a health threat In addition, any migration of mud contaminants into
surface water is not likely to pose an ecological threat at any facility because, based on the Agency's leach
tests, contaminants do not appear to leach from the muds in concentrations that are potentially harmful to
aquatic organisms. While the pH of the leachate could be high, pH excursions in surface waters are more
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Chapter 3: Alumina Production 3*9
likely to be caused by periodic direct discharges, not the low-level chronic loads that are expected through
ground-water discharges.
Air Release, Transport, and Exposure Potential
Because all of the constituents of potential concern are nonvolatile inorganics, red mud contaminants
can only be released to air in the form of windblown dust During the operating phase of the impoundments,
the potential for dusting from the muds is virtually non-existent because the muds are submerged beneath
liquids. When the impoundments are closed and the muds have dried, there is a potential for particles of the
mud to be released to air (none of the facilities practice any dust suppression/control measures). This is
especially true at the facilities in arid areas (Gregory and Point Comfort, Texas) where the muds are less likely
to remain moist due to precipitation. The muds dry to a very fine particle size (sometimes less than 1
micrometer) which is highly susceptible to wind erosion. Based on sample analyses of the muds, the only
constituents that could pose a threat through the inhalation pathway are arsenic and chromium, and this would
only be a threat if dust particles are released from dried impoundments in a high concentration (that equals
or exceeds the National Ambient Air Quality Standard for paniculate matter). The nearest residence at the
Gregory facility is 120 meters away, and the nearest residence at the Point Comfort facility is roughly 400
meters away. Considering these distances and the relatively low concentration of contaminants in the muds,
airborne concentrations of arsenic and chromium at the existing residences closest to these facilities are likely
to be below levels of concern. Dust could be a problem at these facilities, however, if people were allowed
to come into close contact with the muds after closure.
Proximity to Sensitive Environments
None of the bauxite refining facilities within the scope of this analysis are located in or within one
mile of karst terrane, a fault zone, the habitat of an endangered species, a National Park, a National Forest,
or a National Wildlife refuge. In addition, none of the facilities are lr ated in a wetland, although two
facilities are located within one mile of wetlands.
Risk Modeling
Based upon the evaluation of intrinsic hazard and the analysis of factors that influence risk presented
above, and upon a comprehensive review of information on documented damage cases (presented in the next
section), EPA has concluded that the potential for red muds to impose significant risk to human health or the
environment if managed according to current practice is low. Therefore, the Agency has not conducted a
quantitative risk modeling exercise for this waste. (See sections 33.3 and 3.7 below for further discussion.)
3.3.2 Damage Cases
State and EPA regional files were reviewed in an effort to document the performance of waste
management practices for red muds from bauxite refining at the five active facilities and at one inactive bauxite
facility.14 The inactive facility was the Alcoa plant in Bayden, North Carolina. The file reviews were
combined with interviews with State and EPA regional regulatory staff. Through these case studies, EPA
found documented environmental damages associated with red mud discharges to surface water at one facility:
Ormet in Burnside, Louisiana. EPA also found evidence of ground-water contamination at the Gramercy,
Louisiana facility, but this appears to be associated with brine muds that are not within the scope of this
study.15
14 Facilities are considered inactive for purposes of this report if they are not currently engaged in primary mineral processing.
15 This facility generates brine muds that result from the purification of raw brine (solution mined from Sorrento, Louisiana salt domes)
for use in the production of caustic and chlorine.
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3-10 Chapter 3: Alumina Production
Ormet in Burnside, Louisiana
Ormet Corporation's Aluminum plant is located south of Baton Rouge in Burnside, on LA
Highway 22. The facility is situated near the Mississippi River. The processing unit generating red muds has
been operational since 1958.16
The facility contains four red mud lakes, referred to as Nos. 1,2, 3, and 4. These impoundments have
a combined surface area of 85 hectares (210 acres).17 Impoundments Nos. 1 and 2 have been inactive since
1984. Impoundment 4 is the most recently constructed of the 4 pits.18
During heavy rainfall events when excess water has accumulated in closed red mud impoundments
1 and 2, Ormet has discharged to a tributary of the "Panama Canal" on an emergency basis.19'20 The
Panama Canal flows from east to west along the northern boundary of the facility, through residential areas,
and is a source of domestic water in some cases.21'22
Discharge of excess waters has resulted in high pH excursions in some cases. For example, excess
water was discharged to the Panama Canal between May 23 and May 27, 1983. Due to improper operation
of the neutralization station, combined with communications problems, high pH excursions were not detected
until after the discharge event. The excessive pH levels ranged from 9.4 to 10.2 for 4.5 hours on May 23,1983,
and from 9.7 to 9.8 for 7.5 hours on May 24, 1983.23
Ormet has stated that "the Panama Canal cannot readily assimilate the discharge of excess rainwater
from the Red Mud Impoundments." Ormet goes on to state that "flow in the Panama Canal stops on some
occasions, and on others actually flows backward because of wind or tidal action."24 The Louisiana
Department of Environmental Quality (LADEQ) raised concern over the impact of these discharges on the
Panama Canal, and requested that Ormet look into the option of discharging to the Mississippi River.25
The emergency discharges to the Panama Canal have imparted a red color to the canal water, resulting in
complaints from local residents.26'27 Investigation into this phenome )n led LADEQ to conclude that
"Ormet. 1989. National Survey on Solid Wastes from Mineral Processing Faculties (File # 347). 4/5/89.
17 Ibid.
18 EPA Region 6. 1984. Potential Hazardous Watte Site - Site Inspection Report. 9/5/84.
19 Onnet. 1983. Letter from F.C. Sikes to 1) M.O. Knudson, EPA Region 6 Water Management Division; and 2) J.D. Givens,
LADNR Water Pollution Control Division, Re: None (pH excursions on 5/23 and 5/24/83). 6/2/83.
20 Ormet. 1985. Letter bom F.G. Sikes to G. Aydell, Office of Water Resources, LADEQ, Re: None (Ormet's progress toward
ameliorating conditions in Panama Canal). 12/20/85.
21 Ormet. 1971. Map of Waste Water Discharge into Panama Canal, Burnside, LA. 5/11/71.
22 Ormet. 1986. Letter from FIX Sikes to K. Huffman, EPA Region 6 Industrial Permits Section, Re: NPDES Permit No.
LA0005606. 6/9/86.
23 Ormet. 1983. Letter from F.G. Sikes to 1) M.O. Knudson, EPA Region 6 Water Management Division; and 2) J£>. Givens,
LADNR Water Pollution Control Division, Re: None (pH excursions on 5/23 and 5/24/83). 6/2/83.
24 Ormet. 1986. Letter from FD. Sikes to K. Huffman, EPA Region 6 Industrial Permits Section, Re NPDES Permit No.
LA0005606. 6/9/86.
25 Ormet. 1985. Letter from F.G. Sikes to G. Aydell, Office of Water Resources, LADEQ, Re: None (Ormet's progress toward
ameliorating conditions in Panama Canal). 12/20/85.
26 Louisiana Department of Natural Resources. 1985. Division of Water Pollution Control Complaint Form, Re: Discharges from
Ormet Corp. 2/8/85.
27 Ormet. 1986. Letter from F.D. Sikes to K. Huffman, EPA Region 6 Industrial Permits Section, Re: NPDES Permit No.
LA0005606. 6/9/86.
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Chapter 3: Alumina Production 3-11
the problem was primarily aesthetic, and no formal action was taken.28 However, LADEQ did contact
Onnet about "ameliorating the conditions in the Panama Canal."29
In 1987, LADEQ's Ground Water Protection Division expressed concern that Ormet's proposal to
close the red mud impoundments in their present condition would allow production of leachate and possible
ground-water contamination. LADEQ also suggested continued ground-water monitoring as a pan of
closure.30 Ground-water monitoring data were not found in the documents reviewed.
3.3.3 Findings Concerning the Hazards of Red muds
Potential danger from red muds is low primarily because the intrinsic hazard of the waste due to the
presence of toxic constituents is relatively low. Specifically, the waste does not exhibit any characteristics of
hazardous waste (see 40 CFR 261) and only arsenic and chromium are present in sufficient concentrations in
the mud solids that could conceivably pose a cancer risk greater than 10"5 under conservative ("worst case")
exposure scenarios (i.e., routine incidental ingestion of the muds, inhalation of airborne paniculate
concentrations at the National Ambient Air Quality Standard). The radium-226 concentration is
approximately equal to EPAs standard for the cleanup of inactive uranium mill tailings sites, indicating a
minor potential for radiation risk if the material were used in home construction (which it is not), or if the
mud lakes after closure are allowed to be used in an unrestricted manner. Given current management
practices, these exposure scenarios are unlikely. After closure, however, direct access to the muds should be
restricted and dust could be a problem at some facilities due to the small particle size of the material and the
relatively arid setting of some facilities.
Available laboratory (EP) leachate data indicate that only arsenic (in two out of four samples from
two out of three facilities sampled) and selenium (in one sample) are present in leachate from the muds at
concentrations that exceed the conservative screening criteria by a narrow margin (a factor of three).
Qualitative review of the potential for transport and exposure in ground and surface water indicates that the
potential exists at several facilities for mud contaminants to migrate ir o the environment; however, the
migration is not expected to cause significant health or environmental irr. pacts for the reasons stated above.
In addition, it is likely that actual leachate concentrations are lower than the laboratory leachate considered
here because the EP leaching procedure may overestimate leachate concentrations due to the use of an acidic
leaching solution for what is a very alkaline waste material.
The finding that the potential for danger to health and the environment is generally low is consistent
with the fact that only very limited documented damages were identified. No documented damages to ground
water associated with red muds were identified. At one facility, emergency surface water discharges with a
pH > 9 from red mud lakes have occurred as the result of a storm event
28 Louisiana Department of Environmental Quality (LADEQ). 1985. Letter from PI> Norton, Office of Water Resources, to W_A.
Fontenot, LA Dept. of Justice, Lands and Natural Resources Division, Re: None (Red water complaint in the Panama Canal). 3/28/85.
29 LADEQ. 1985. Letter from G.R. Aydell, Office of Water Resources, to F.C. Sikes, Onnet Corp., Re: None (red color imparted
to Panama Canal). 6/27/85.
30 LADEQ. 1987. Office of Solid and Hazardous Waste, Memorandum from G.H. Cramer to P. Miller, Solid Waste Division, Re:
Comments Concerning Onnet Closure GD-005-1484, Ascension Parish. 10/28/87.
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3-12 Chapters: Alumina Production
3.4 Existing Federal and State Waste Management Controls
3.4.1 Federal Regulation
Under the Clean Water Act, EPA has the responsibility for setting "effluent limitations," based on
the performance capability of treatment technologies. These "technology based limitations" which provide the
basis for minimum requirements of NPDES permits, must be established for various classes of industrial
discharges, which include a number of ore processing categories.
Permits for mineral processing facilities may require compliance with effluent guidelines based on best
practicable control technology currently available (BPT) or best available technology economically achievable
(BAT). BPT and BAT requirements for bauxite refining specify that there shall be no discharge of process
wastewater pollutants to navigable waters (40 CFR 421.10-16), except that discharge is permitted in months
in which precipitation exceeds evaporation. Wistewater quality limits for such discharges are not established
by the regulations. In the case of States which have not been delegated authority by EPA to manage the
NPDES program, such as Texas and Louisiana, EPA includes permit limits necessary to achieve State water
quality standards for the effluent discharges.
EPA is unaware of any other specific Federal management control or pollutant release requirements
that apply specifically to bauxite red mud wastes.
3.4.2 State Regulation
The five facilities in the alumina sector are located in Arkansas, Louisiana, and Texas. Two of these
states, Louisiana and Texas, were chosen for regulatory review for the purposes of this report (see Chapter 2
for a discussion of the methodology used to select states for detailed regulatory study). Both of the study
states exclude mineral processing wastes from hazardous waste regulatic-. classify red muds from alumina
production as industrial solid wastes, and have air quality regulations c standards that apply to red mud
management and disposal activities.
Of the two study states, Louisiana appears to be most comprehensive in its coverage of red muds from
alumina production. Although no requirements have been drafted specifically for red mud impoundments,
facility owner/operators must comply with general solid waste disposal provisions for soils (e.g., stability,
permeability), hydrologic characteristics, precipitation run-on and run-off, location standards, security, safety,
and waste characterization. Moreover, both alumina facilities in Louisiana maintain surface impoundment
permits for their red mud impoundments, and must meet general industrial waste surface impoundment
requirements such as run-on controls, liner requirements, design standards (e.g., to prevent overtopping and
minimize erosion), waste characterization, and ground-water monitoring requirements. Surface impoundments
must be dewatered and clean-closed (i.e., all residuals removed) or closed according to solid waste landfill
closure provisions. Louisiana also requires that owners/operators of all industrial solid waste landfills and
surface impoundments maintain financial responsibility for the closure and post-closure care of those waste
units. Although Louisiana does not have an approved NPDES program, the state does require state permits
for the discharge of leachate or run-off to surface waters. Finally, Louisiana air regulations require that its
alumina processing facilities manage their wastes in a manner necessary to minimize fugitive dust emissions.
As with Louisiana, Texas classifies mineral processing wastes, including red muds from the production
of alumina, as industrial solid wastes. Because both alumina facilities in Texas dispose of their wastes on
property that is both within SO miles of the respective facility and controlled by the facility owner/operator,
the state has not required either facility to obtain a solid waste disposal permit. Both facilities have notified
the state of their waste disposal activities. Facilities discharging to surface water must obtain both Federal
NPDES and Texas water quality permits. According to Texas officials, the Reynolds alumina facility does not
discharge to surface water and thus does not maintain a NPDES or state discharge permit. Finally, Texas
officials noted past problems with fugitive dust emissions from the red mud disposal units at both facilities
and indicated that enforcement actions have been taken against the Reynolds facility. The Reynolds facility
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Chapter 3: Alumina Production 3-13
now uses a flooding process to keep the muds completely under water, while the Alcoa facility places coarse
river sand over red mud areas that become dry in order to control emissions.
In summary, the alumina sector states studied in detail for this report, Louisiana and Texas, classify
and regulate red muds from the production of alumina as industrial solid wastes. Of the two states, Louisiana
has been more comprehensive in the kinds of environmental controls imposed on the management and
disposal of these red muds under their solid waste authorities. Both Louisiana and Texas also require State
water quality permits for discharges to surface water, in addition to Federal NPDES requirements, and have
air quality regulations that address fugitive dust emissions. Texas in particular has had problems with fugitive
dust emissions at both of its alumina facilities and has taken action in order to ensure that such emissions are
controlled.
3.5 Waste Management Alternatives and Potential Utilization
As noted above, the available data indicate that red muds do not exhibit any of the characteristics of
hazardous waste. Consequently, the issue of how alumina producers might modify their operations or waste
management practices or be stimulated to develop alternative uses for red muds in response to prospective
hazardous waste regulation is moot. Nevertheless, this section provides a brief summary of current red mud
waste management practices and potential areas of utilization.
Responses by bauxite processors nationwide to the SWMPF Survey indicate that none of the red mud
was sold or used for commercial purposes in the United States in 1988. Although red muds are not currently
being utilized efforts have been made to find commercial uses for these residues. Several processes have been
developed to recover iron from the red mud residues,31-32 and the potential exists to use red muds as a
raw material in the iron and steel industry.33 Alumina and titanium dioxide recovery from bauxite muds is
also technically feasible, as well as recovery of other rare metals such as gallium, vanadium, and scandium.34
Processing for recovery of metals other than iron, however, is not economically viable at present
In addition to metal recovery, other methods of potential util ation of bauxite muds include use
in making construction blocks, bricks, portland cement, in lightweight aggregate to make concrete, in plas-
tic and resin as filler, pigments, and applications in making ceramic products.35-36137 Research has also
been conducted on the potential use of red muds as a reagent in various proposed waste treatment
processes.38*39
31 Parekh, BX and W.M. Goldberger. Utilisation of Baver Process Muds: Problems and Possibilities. Proceedings of the Sixth Mineral
Waste Utilization Symposium, Chicago, IL, ed. Eugene Aleshin, 2-3 May 1978, pp. 123-132.
32 Sh.m.iuMin. M. Metal Recovery form Scrap and Waste. Journal of Metals, February, 1966, pp. 29-30.
33 Steel from Aluminum Waste: The Grate Electric Process Using "Red Mud" as Iron Ore, Heat Engineering, April/June 49:2, 1979,
p. 23.
34 Parekh, B.K. and W.M. Goldberger, og. at., pp. 123-124.
35 Parekh, B.K. and W.M. Goldberger. i itiiiMtinn of Bayer Process Muds: Problems and Possibilities. Proceedings of the Sixth Mineral
Waste Utilization Symposium, Chicago, IL, ed. Eugene Aleshin, 2-3 May 1978, pp. 123-132.
* Miller, R.H. and RJ. Collins. Waste Material as Potential Replacements for Highway Aggregates. National Cooperative Highway
Research Program Report 166, 1976, p. 50.
37 Thokur, R.S. and B .R. Sant. Utilization of Red Mud: Part I • Analysis and Utilization as Raw Material for Adsorbents. Building
Materials, Catalysts. Fillers. Paints and Pigments. Journal of Scientific and Industrial Research, Vol. 42, February 1983, pp. 101-105.
38 Parekh, and Goldberger, oj>. at.,
M Thokur, and Sant, ojj. cjt,
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3-14 Chapter 3: Alumina Production
3.6 Cost and Economic Impacts
Because the available data indicate that red muds do not exhibit any of the characteristics of
hazardous waste, the issues of how waste management costs might change because of new requirements
associated with hazardous waste regulation under RCRA Subtitle C and what impacts such costs might impose
upon affected facilities are not meaningful. Consequently, no incremental costs or associated economic
impacts would result from a decision to remove red muds from the Mining Waste Exclusion.
3.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For the
special waste in question (red muds), these categories address the following three major topics: (1) potential
for and documented danger to human health and the environment; (2) the need for and desirability of
additional regulation; and (3) the costs and impacts of potential Subtitle C regulation.
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of red muds is relatively low compared to the other mineral processing wastes
studied in this report. The muds do not exhibit any of the four characteristics of hazardous waste, and only
chromium was detected in the muds in a concentration that exceeds the risk screening criteria used in this
analysis by a factor of 10. The concentration of radium-226 in the muds approximately equals EPA's standard
for the cleanup of inactive uranium mill tailings sites, indicating a slight potential for radiation risk if the muds
were used in home construction (which they are not), or if the mud lakes after closure were allowed to be used
in an unrestricted manner. In addition, the alkaline nature (i.e., high p''•' i of the muds is expected to limit
plant growth on the dried, closed impoundments.
Based on an examination of the existing conditions at the five active bauxite refining facilities, EPA
concludes that the management of red muds may allow contaminants to migrate into the environment, but that
the potential for significant exposure to these contaminants is low. Specifically:
• There is a potential for contaminants to migrate into shallow ground water because the
muds are managed in impoundments and are submerged below liquids that may drive
contaminants to the subsurface, the bases of most impoundments used to manage the
muds extend beneath the water table, and only two impoundments are equipped with
leachate collection systems. However, useable ground water at each site is considerably
deeper (and thus more protected) and the concentration of any released contaminants
is expected to be below levels of concern at possible downgradient exposure points.
• It is also possible for contaminants from the impoundments to migrate into nearby
surface waters at three facilities that are within 60 meters of a water body. However,
this migration is not expected to cause significant impacts because the potential
receiving water bodies have a moderate to large assimilative capacity and resulting
contaminant concentrations are likely to be well below human health and ecological
protection benchmarks.
• When the impoundments have closed and the muds have dried, there is also a potential
for fine particles of the mud to be blown into the air as dust. Considering the distances
to existing residences and the low concentrations of contaminants in the muds, however,
airborne concentrations at the residences are likely to be below levels of concern.
The finding that the potential for danger to human health and the environment is low is consistent
with the fact that only one very limited documented damage case attributable to the muds has been identified.
State and EPA Regional files were reviewed in an effort to document the performance of red mud
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Chapter 3: Alumina Production 3-15
management practices at the five active bauxite facilities and at one inactive facility. No documented damages
to ground water associated with red muds were identified. At one facility, emergency surface water discharges
with a pH > 9 from the red mud lakes have occurred as the result of storm events. This type of discharge
is already regulated under the NPDES program.
Likelihood That Existing Risks/Impacts Will Continue in the Absence
of Subtitle C Regulation
As summarized above, the current red mud management practices and environmental conditions at
the five active bauxite facilities may allow some contaminant migration into ground water, surface water, and
air, both now and in the future. However, given the generally low concentrations of contaminants in the muds,
this migration should not pose a serious human health and environmental threat under reasonable
mismanagement scenarios. EPA believes that, after the impoundments have been closed, direct access to the
muds should be restricted to avoid radiation hazards and risks. Furthermore, it would be prudent to control
fugitive dust emissions from dried or closed impoundments, especially at the facilities located in arid settings,
because the dried muds are susceptible to wind erosion and inhalation exposures conceivably could occur if
people moved close to inactive impoundments in the future.
EPA believes that the low-risk conclusion for the five active bauxite facilities accurately reflects future
conditions because the muds are not likely to be generated and managed at alternate sites. In addition, the
quantity of the muds is so large that it is unlikely that the muds will be dredged from the impoundments in
which they settle and disposed of elsewhere. Current industry trends also indicate that construction of new
bauxite refining facilities in the U.S. is not likely. In addition, the muds historically have not been used off-site
extensively. Although a variety of approaches to utilization of the muds have been researched, including use
in making construction blocks, bricks, and portland cement, and recovery of iron and other metals, none of
these alternatives appear economically viable at present or in the foreseeable future.
The extent of state regulation of red muds appears to be comme urate with the risks posed by this
waste. The five active facilities are located in Louisiana, Texas, and Arka jsas, of which Louisiana and Texas
were studied in detail for purposes of this report. Both Louisiana and Texas exclude mineral processing wastes
from hazardous waste regulation and classify red muds generated by alumina production as industrial solid
wastes. Although Louisiana's regulations do not contain provisions tailored specifically to red muds, the state
does apply surface impoundment and landfill closure and financial responsibility requirements to the muds
in a fairly extensive manner. Texas has established standards for all aspects of the control of industrial solid
waste. Nevertheless, neither of the two facilities in Texas are required to obtain a permit, because both
dispose of their wastes on property owned or controlled by the facility owner/operator, and thus are only
subject to notification requirements. Both Louisiana and Texas require State wastewater discharge permits
in addition to Federal NPDES permits, and both states address fugitive dust emissions in the air permits issued
to the alumina facilities within their jurisdictions.
Costs and Impacts of Subtitle C Regulation
Because of the low risk potential of red muds, the general absence of documented damages associated
with these materials, and the fact that this material does not exhibit any characteristics of hazardous waste,
EPA has not estimated the costs and associated impacts of regulating red muds from bauxite refining under
RCRA Subtitle C.
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Chapter 4
Sodium Dichromate Production
The sodium chromate and dichromate (also known as bichromate) production sector consists of two
facilities that, as of September 1989, were active and reported generating a special mineral processing waste:
treated residue from roasting/leaching of chrome ore. Prior to treatment, the roast/leach residue is not a
special waste and thus, is subject to applicable RCRA Subtitle C requirements (see 55 FR 2322, January 23,
1990.)1 Facilities that are no longer operational, such as the Allied-Signal facility in Baltimore, MD, are not
addressed in this report. The data included in this chapter are discussed in additional detail in a technical
background document in the supporting public docket for this report.
4.1 Industry Overview
Sodium dichromate, converted from sodium chromate, is the primary feedstock for the production
of chromium-containing chemicals and pigments. Chromium-containing chemicals (e.g., chromic acid, basic
chromium sulfate, tanning compounds) are used in chromium plating, etching, leather tanning, water
treatment, and as catalysts. Other uses of chromium-containing chemicals are in drilling operations to provide
drilling mud fluidity and in wood preservative processes to bind copper and arsenic to wood. Chromium
pigments represent the largest use of chromium in the chemical industry, with sodium dichromate used to
manufacture a multitude of pigments (e.g., chrome green and yellow, zinc chromate) that are used in paints
and inks, often for materials that require corrosion inhibition.2
The two sodium dichromate production facilities studied in this report are the Corpus Christi, Texas
plant operated by American Chrome and Chemicals (ACC) and owned by Harrisons and Crossfield Inc.
(Harcross), and the Castle Hayne, North Carolina plant owned and operated by Occidental Chemical
Corporation (OCC). The ACC facility initiated operations in 1962 and was modernized in 1985; the OCC
facility began operations in 1971 and was modernized in 1982. The annual production capacity, total 1988
production, and rate of capacity utilization for the two facilities as reported in the SWMPF Surveys have all
been designated confidential by the facilities and, therefore, are not reported in this document.3 A published
data source lists the annual sodium dichromate production capacity4 of the ACC plant at 41,000 metric tons
and the OCC plant as 109,000 metric tons.5 According to Bureau of Mines sources, long term capacity
utilization (1990 to 1995) is forecast to be 100 percent of capacity.6
Because these two facilities have classified their production statistics as confidential, no specific
information can be given on production trends in the sodium chromate and dichromate industries. The U.S.
Bureau of Mines, however, reports that apparent U.S. consumption of chromium has risen from 343,000 metric
tons in 1985 to 540,000 metric tons in 1989.7
1 The residue from roasting/teaching of chrome ore is not "low hazard" (as defined by EPA for purposes of determining the scope of
the Mining Waste Exclusion as it applies to mineral processing wastes) when it is removed from the production process and, thus, is not
a special waste at the point of generation. However, after treatment (pH adjustment and sulfide reduction), as employed by the two
facilities, the residue is "low hazard" and therefore is a special waste because it is also high volume.
2 Bureau of Mines, 1987. Minerals Yearboot Ed.; p. 373.
3 American Chrome and Chemicals and Occidental Chem. Corp. Company Responses to the "National Survey of Solid Wastes from
Mineral Processing Facilities," U.S. EPA, 1989.
4 Capacities are on a 100 percent sodium dichromate basis and include sodium chromate.
5 SRI International, 1987. Directory of Chemical Producers-United States. Ed.; p. 964.
6 Bureau of Mines. 1990. Personal communication with Commodity Specialist John Papp.
7 John F. Papp, 1987. U.S. Bureau of Mines, "Chromium,1' Minerals Yearbook. Ed., pp. 221, 223.
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4-2 Chapter 4: Sodium Oichromate Production
Substitutes for chromium chemicals result in increased costs or poor performance.8 Thus, the future
demand for sodium chromate and dichromate will fluctuate directly with the future demand for chromium
pigments and the chromium containing chemicals used in chromium plating, etching, tanning, and water
treatment, and as catalysts. The chromium chemical industry has historically shown a slow but steady growth
rate;9 there is no indication that this trend will change in the future.
Sodium chromate and dichromate are produced by a process in which ground chrome ore and soda
ash are mixed (lime and/or leached calcine are sometimes added as well), roasted in an oxidizing atmosphere,
and leached with weak chromate liquor or water, as shown in Exhibit 4-1.10 The resulting leach liquor is
separated from the remaining leach residue. The roasting/leaching sequence is repeated at the ACC facility;
that is, two complete chromium extraction cycles are performed prior to removal of the residue. The leach
residue is then treated, as discussed below. The treatment residue from this operation is the special waste;
it is disposed on-site at both facilities.11 The leach solution contains unrefined sodium chromate; this liquor
is neutralized and then filtered to remove metal precipitates (primarily alumina hydrate).12 The alumina-free
sodium chromate may be marketed, but the predominant practice is to convert the chromate to the dichromate
form. The OCC facility uses a continuous process that involves treatment with sulfuric acid, evaporation of
sodium dichromate, and precipitation of sodium sulfate. Sodium sulfate may be sold as a byproduct or
disposed; the dichromate liquor may be sold as 69 percent sodium dichromate solution or returned to the
evaporators, crystallized, and sold as a solid. The ACC plant uses carbon dioxide (CO^ to convert the
chromate to dichromate; this process has the advantage of not generating a sulfate sludge.
Treatment of the leach residue consists of pH adjustment and sulfide reduction. The ACC facility
pumps the leach residue directly to a dedicated treatment unit, in which sulfuric acid and sodium sulfide are
used to induce the desired chemical changes in the residue, while at the OCC plant, the untreated residue is
pumped to a wastewater treatment plant which receives, and apparently combines, several other influent
streams prior to treatment with several different chemical agents. At both plants, the treated residue is
pumped in slurry form to disposal surface impoundments.
4.2 Waste Characteristics, Generation, and Current Management Practices
The special mineral processing waste generated by sodium dichromate production, treated residue
from roasting/leaching of chrome ore, is a solid material, though it typically is generated as a slurry containing
particles between 2 mm and about 8 cm (3 inches) in diameter. The treated roast/leach residue is composed
primarily of metallic oxides, such as those of iron, aluminum, silicon, magnesium, and chromium, as well as
sulfates.13 The residue treatment process at both facilities includes a step to reduce hexavalent chromium
(Cr VI) to the trivalent form (Cr III), and to lower the pH of the waste. During its 1989 sampling visit, EPA
observed that the residue (as disposed) has a strong sulfide odor that is indicative of reducing conditions.
Using available data on the composition of the treated residue, EPA evaluated whether the residue
exhibited any of the four characteristics of hazardous waste: corrosrvity, reactivity, ignitability, and extraction
procedure (EP) toxicity. Based on these data and professional judgment, the Agency does not believe the
chromium residue is corrosive, reactive, or ignitable. Further, based on EP and SPLP leach test data for one
sample from the ACC facility, the chromium residue does not exhibit the characteristic of EP toxicity. Using
8 John F. Papp, 1990. U.S. Bureau of Mines, "Chromium," Mineral Commodity Summaries. Ed., p. 45.
9 John F. Papp, 1985. U.S. Bureau of Mines, "Chromium," Mineral Facts and Problems. &L, p. 152.
10 Bureau of Mines, 1985. Mineral Facts and Problems. Ed.; p. 144.
11 American Chrome and Chemicals and Occidental Chemical Company Responses to the "National Survey of Solid Wastes from
Mineral Processing Facilities," U.S. EPA, 1989.
12 Marks, 1978. Encyclopedia of Chemical Technology. Marks, et al., editors; Wiley Intencience, New York, NY, pp. 93-94.
13 Occidental Chemical Corp. Company Responses to the "National Survey of Solid Wastes from Mineral Processing Facilities," U.S.
EPA, 1989.
-------
Chapter 4: Sodium Dichromate Production 4-3
Exhibit 4-1
Sodium Dichromate Production
PROCESS
Soda
Ash Lime
Chromite y T
Ore . . .
t
SPECIAL WASTE
MANAGEMENT
Leach
Solution
i
Roasting -> Leaching
Lea
Resi
^
1 Treatment
V_^
— —
Impure
Sodium ^ Neutralizing
Chromate Filtering
ch 1
due Alumina
Hydrate
A <
}
Refining Sodium
P and ~*
Converting Dichromate
_^ Sodium
Chromate
/Treated Leach^x
^ Resdue^X
f Disposal \
/ Surface \
I Impoundment/
Legend
1 I Production Operation <^__^ Special Waste (^,
Waste Management Unit
the EP test, the concentrations of all eight inorganic constituents with the EP toxicity regulatory levels were
one to two orders of magnitude below the regulatory levels.
Both companies generating this waste indicated that waste generation rate data were confidential
business information. Using alternate sources, EPA estimates the total generation to be approximately 102,000
metric tons/year (mt/yr); the estimated waste to product ratio is 0.68 metric ton of treated residue to each
metric ton of sodium dichromate.
The waste management practice used at both sodium dichromate production facilities is the disposal
of the treated roast/leach residue in large surface impoundments.14 In these impoundments, the treated
roast/leach residue is settled out; the water is removed, treated, and discharged at the OCC facility, and is
typically left in the impoundment (evaporates) at the ACC facility. The settled treated roast/leach residue is
not removed from the impoundments but accumulates in place. The volume of treated roast/leach residue
accumulated on-site at the two sodium dichromate plants is estimated to total more than 1 million metric tons;
the facilities have reported accumulations of 54,000 cubic meters (1.9 million cubic feet) and 440,000 cubic
meters at ACC and OCC, respectively. Other waste streams are co-managed with the treated roast/leach
residue at these facilities.
14 The OCC impoundment at Castle Hayne is actually a quarry. The treated roast/leach residue is co-managed in this quarry with
tailings from another on-site operation (identity is confidential). The ACC impoundment is termed a residue disposal area.
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4-4 Chapter 4: Sodium Dichromate Production
The average surface area of these impoundments is 254,000 square meters (62.8 acres) with a depth
of 7.3 meters (24 feet); the specific impoundments range in surface area from 22,000 square meters and a
depth of 2.5 meters for ACC/Corpus Christi's residue disposal area to a surface area of 486,000 square meters
and a depth of 12 meters at OCC/Castle Hayne's quarry. Neither facility uses a liner or a leachate collection
system, and only Occidental has surface and ground-water monitoring.
4.3 Potential and Documented Danger to Human Health and the Environment
This section addresses two of the study factors required by §8002(p) of RCRA: (1) potential danger
(i.e., risk) to human health and the environment; and (2) documented cases in which danger to human health
or the environment has been proven. Overall conclusions about the hazards associated with treated chromium
roast/leach residue are provided after these two study factors are discussed.
4.3.1 Risks Associated with Treated Residue from Roasting/Leaching of
Chrome Ore
Any potential danger to human health and the environment from the treated residue from roas-
ting/leaching of chrome ore depends on the presence of toxic constituents in the waste that may pose a risk
and the potential for exposure to these constituents.
Constituents of Potential Concern
EPA identified chemical constituents in the treated residue from roasting/leaching of chrome ore that
may potentially present a hazard by collecting data on the composition of the waste and evaluating the intrinsic
hazard of the residue's chemical constituents.
Data on Treated Residue from Roasting/Leaching of Ore Composition
EPA's characterization of the treated roast /leach residue and its leachate is based on data from a 1989
sampling and analysis effort by EPAs Office of Solid Waste (OSW). These data provide information on the
concentrations of 20 metals in samples of both the treated residue and leachate (e.g., EP-toxicity procedure,
SPLP). Wastes from both sodium dichromate production plants within the scope of this study were sampled
and analyzed.
Data on constituent concentrations in solid samples of the waste from the OCC plant are not
available; therefore, concentrations in solid samples cannot be compared for the two facilities. On the other
hand, concentrations from leachate analyses of the treated roast/leach residue were available for both facilities
and generally are consistent across the two facilities and two types of leach tests (i.e., EP and SPLP).
Process for Identifying Constituents of Potential Concern
As discussed in Section 2.2.2, the Agency evaluated the waste composition data summarized above
to determine if treated chromium roast/leach residue contains any chemical constituents that may pose an
intrinsic hazard, and to narrow the focus of the risk assessment. The Agency performed this evaluation by first
comparing constituent concentrations to the screening criteria and then by evaluating the environmental
persistence and mobility of the constituents present in concentrations that exceed the criteria. These screening
criteria were developed using assumed scenarios that are likely to overestimate the extent to which constituents
in the residue are released to the environment and migrate to possible exposure points. As a result, this
process eliminates from further consideration those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic organisms, and air and water resources (see Exhibit 2-3). Given the conservative (i.e., overly
protective) nature of these screening criteria, contaminant concentrations in excess of the criteria should not,
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Chapter 4: Sodium Dichromate Production 4-5
in isolation, be interpreted as proof of hazard. Instead, exceedances of the criteria indicate the need to
evaluate the potential hazards of the waste in greater detail.
Identified Constituents of Potential Concern
Analysis of solid samples of the treated roast/leach residue indicates that none of the waste's
constituents are present at levels above the screening criteria. That is, even under conservative release and
exposure conditions, the residue solids do not appear to contain any constituents in concentrations that could
pose a significant risk.
Exhibit 4-2 presents the results of the comparisons for treated residue leachate analyses, and lists all
constituents for which sample concentrations exceed a screening criterion. Chromium, vanadium, aluminum,
manganese, and arsenic are present at concentrations equal to or slightly greater than at least one of their
respective screening criteria. All of these constituents are inorganics that do not degrade in the environment.
None of the constituents are present at a concentration more than five times a screening criterion,
and arsenic is present at a concentration that is just equal to its human health screening criterion. Vanadium
and arsenic leachate concentrations are high enough that, if the leachate migrated to drinking water sources
with only a 10-fold dilution, long-term ingestion of untreated drinking water could cause adverse health effects.
If the leachate is released and diluted by only a factor of 10, chromium, vanadium, and manganese
concentrations could potentially render affected ground or surface waters unsuitable for a variety of uses (e.g.,
direct human consumption, irrigation, livestock watering). Chromium and aluminum are present in the treated
residue leachate at concentrations that, if released to surface waters with a 100-fold dilution or less, could
exceed criteria for the protection of aquatic Me. It is important to clarify that, while the concentrations of
these five constituents exceed the conservative screening criteria, no constituents were measured in
concentrations that exceed an EP-toxicity regulatory level.
These exceedances of the screening criteria, by themselves, do not demonstrate that the residue poses
a significant risk, but rather indicate that the waste may present a hazard under a very conservative,
hypothetical set of release, transport, and exposure conditions. To determine the potential for the residue to
cause significant impacts, EPA proceeded to the next step of the risk assessment to analyze the actual
conditions that exist at the facilities that generate and manage the waste.
Release, Transport, and Exposure Potential
This analysis evaluates the baseline hazards of the waste as it was generated and managed at the two
sodium dichromate production plants in 1988. It does not assess the hazards of off-site use or disposal of the
treated residues because the treated residues are currently managed only on-site and are not likely to be
managed off-site in the foreseeable future. In addition, the following analysis does not consider the risks
associated with variations in waste management practices or potentially exposed populations in the future
because of a lack of data on which to base projections of future conditions. Alternative practices for the
management of treated chrome roast/leach residue, however, are discussed in Section 4.5.
Ground-Water Re/ease, Transport, and Exposure Potential
As discussed above, leachate from the treated chromium residue contains five constituents in
concentrations that exceed the risk screening criteria. However, given the existing residue management
practices and the neutral pH conditions that are expected to exist in and under the waste management units,
vanadium, aluminum, and manganese have a strong tendency to bind to soil These three constituents in
leachate from the treated residue, therefore, are relatively immobile in ground water (in the event that they
are released to ground water). Moreover, the residue treatment process employed is designed to reduce
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4-6 Chapter 4: Sodium Dichromate Production
Exhibit 4-2
Potential Constituents of Concern in
Treated Chromium Roast/Leach Ore Residue Leachate(a)
Potential
Constituents
of Concern
Chromium
Vanadium(e)
Aluminum'6*
Manganese
Arsenic*"*
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
2/2
2/2
2/2
1/2
1/2
Screening Crrteria(b)
Resource Damage
' Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Human Health*
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
2/2
1/2
1 12
1 12
2/2
1/2
1/2
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
2/2
1 12
1 12
1 12
2/2
1 12
1 12
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that
exceeds a relevant screening criterion. The screening criteria values are shown in Exhibit 2-3 in Chapter 2 of this
report Constituents that were not detected in a given sample were assumed not to be present in the sample. Unless
otherwise noted, the constituent concentrations used for this analysis are based on EP leach test results.
(b) Human hearth screening criteria are based on cancer risk or noncancer health effects. 'Human health* screening
criteria noted with an '*' are based on a 1x10's lifetime cancer risk; others are based on noncancer effects.
(c) Data for this constituent are from SPLP leach test results.
chromium to the trivalent form, which is relatively immobile in typical ground-water systems.15 Therefore,
among the constituents of potential concern in leachate from the treated residue, only arsenic would be
expected to be readily transported in typical ground-water environments, if released.
Both sodium dichromate production facilities manage the treated residue in units that have no
engineered ground-water release controls such as liners or leachate collection systems. However, the ground-
water release and transport potential of these units differ significantly:
The OCC plant in North Carolina discharges the residue slurry into a 49 hectare (120
acre) quarry that is 12 meters deep. The depth of supernatant liquid in this im-
poundment provides a large hydraulic head that may produce a considerable force to
drive liquids from the quarry into the underlying aquifer. Because the quarry is located
in karst terrain (i.e., irregular topography characterized by solution features in soluble
rock), any liquids released from the quarry to the aquifer located six meters beneath the
quarry could potentially flow long distances directly through conduits in the bedrock
(i.e., with minimal contaminant dilution and attenuation) to potential exposure points.
• The ACC facility in Texas discharges the residue slurry to an unlined disposal area that
has little or no standing water except during storm events and immediately following
deposition of fresh residue slurry. Water is removed from the unit via a network of
drainage ditches, by evaporation, and by seepage into the ground. Although there is
little hydraulic head to drive the flow of contaminants from the unit, both slurry water
15For all other mineral processing wastes evaluated in this report, chromium is assumed to be present in its hexavalent form and,
therefore, to be relatively mobile in ground water.
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Chapter 4: Sodium Dichromate Production 4-7
and stormwater potentially can leach contaminants from the residue into the subsurface.
The potential for slurry water and stormwater to infiltrate to ground water from this
unit may be limited to some degree by the presence of relatively impermeable subsurface
materials (i.e., composed primarily of clay) in the vicinity of the site.
Given these management unit and hydrogeological characteristics, the potential for seepage from the disposal
units to migrate into ground water is relatively high at the North Carolina facility and moderate at the Texas
facility. Ground-water monitoring data further support this assessment. Monitoring of ground water at the
North Carolina facility has indicated that drinking water standards for chloride and pH have been exceeded
downgradient (but not upgradient) of the waste management area. While these contaminants are not
associated with the treated chromium residue, the presence of contaminants in the ground water indicates the
potential for contaminants to leach into ground water at this site.16 Ground-water contamination has also
been documented at the Texas facility (see Section 4.3.2). Although the ground-water contamination at the
Texas facility has not been attributed to the treated residue management unit, the presence of contamination
again indicates that hydrogeologic conditions at this location do not preclude the potential release of residue
constituents to ground water.
Ground-water flow in karst terrain, such as that at the OCC plant, is typically characterized as conduit
flow that does not provide the intimate contact between aquifer material and ground water that occurs in
typical porous media aquifers. Consequently, the constituents of potential concern (i.e., trivalent chromium,
vanadium, aluminum, and manganese) that would not be mobile in typical ground-water environments can
migrate more readily in karst limestone aquifers, and may be mobile along with arsenic at the OCC plant.
Currently, there are no residential or public water supply withdrawals from ground water within
1.6 km (1 mile) downgradient of either facility. Therefore, current human health risks resulting from drinking
water exposures are not expected. Potential releases of arsenic, chromium, vanadium, and manganese from
the waste to the aquifer at the OCC plant, and potential releases of arsenic at the ACC plant could restrict
potential future uses of the ground water, but this threat is very minor given the low concentration of the
waste leachate. In theory, contaminants migrating into ground water at the OCC facility could remain at levels
above the screening criteria for relatively long distances because conduit flow does not disperse contaminants
as readily as diffuse flow in porous media. However, in reality, any contaminants released to ground water
at the OCC facility are likely to discharge directly into the adjacent northeast Cape Fear River, as described
in the next section.
Surface Water Release, Transport, and Exposure Potential
Constituents of potential concern in treated roast/leach residue could theoretically enter surface waters
by either migration of leachate through ground water that discharges to surface water, or direct overland
(stormwater) run-off of dissolved or suspended materials. As discussed above, arsenic, chromium, aluminum,
manganese, and vanadium leach from treated chrome residue at levels above the screening criteria. Given the
characteristics of the units currently used to manage this waste at the two sodium dichromate production
facilities and the hydrologic setting of the plants, the potential for releases of treated residue constituents to
surface waters varies between the two plants.
The OCC plant in North Carolina is located adjacent to the Northeast Cape Fear River. Because
the waste is managed as a sludge at the bottom of a quarry that is 12 meters deep, however, it is unlikely that
overland flow of stormwater run-off could carry the waste to the river. Ground-water discharge to surface
water could potentially release contaminants from the residue sludge to the river at concentrations above the
screening criteria. However, resulting contaminant concentrations in the river downstream of the facility are
expected to be negligible because the large flow of the river (1,250 mgd) can provide substantial dilution, and
the constituents that exceed the screening criteria exceed it by a factor of less than five.
16
The facility did not provide information on the possible sources of the observed ground-water contamination.
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4-8 Chapter 4: Sodium Dichromate Production
The ACC plant in Texas is located less than 50 meters from the Corpus Christi shipping channel.
Releases from the treated residue disposal area are expected to be moderated by run-on/run-off controls
designed to restrict surface run-off of stormwater and slurry water from the unit. As discussed above, the
potential for contamination of ground water is moderate at this facility, and, consequently, contaminated
ground water potentially could discharge to the shipping channel. However, because the Agency's comparison
of treated chrome residue concentrations to screening criteria does not indicate any potential impacts on
saltwater ecosystems or restrictions on potential beneficial uses of saltwater, threats to the shipping channel
water quality from treated chromium residue appear unlikely.
Air Release, Transport, and Exposure Potential
EPA's comparison of constituent concentrations to screening criteria did not identify any potential
constituents of concern for the air pathway. Consequently, if airborne releases were to occur, possibly due to
future removal of the residue sludge from the current management areas, chrome residue should pose no
human health threats via the air pathway. Air pathway threats from current management of the residue at
the OCC plant are further diminished because the waste is managed as a sludge at the bottom of a quarry,
submerged beneath a liquid.
Proximity to Sensitive Environments
Both the OCC and ACC plants are located in environments that are vulnerable to contamination or
have high resource value. Because the OCC plant is located in a 100-year floodplain, large releases
occasionally could occur in the event of a large flood. The OCC plant also is located in an area of karst
topography, which may permit the ready transport of contaminants if they are released to ground water. Both
sodium dichromate production facilities are within 1.6 km (1 mile) of a wetland area. However, because the
ground-water and surface water release potential at the ACC facility is considerably smaller, only the wetland
area near the OCC plant may be potentially threatened by releases from the residue. Wetlands are commonly
entitled to special protection because they provide habitats for many forms of wildlife, purify natural waters,
provide flood and storm damage protection, and afford a number of other benefits.
Risk Modeling
The intrinsic hazard of the treated residue is generally low because the residue does not exhibit any
of the four characteristics of a hazardous waste and contains only five constituents that exceed the screening
criteria by a narrow margin (less than a factor of five). Migration into ground and surface water is possible
at both sites, but it is not expected to cause significant human health or environmental impacts for the reasons
outlined above. In addition, there are no documented cases of damage attributable to the treated residue (as
presented in the next section) and the Agency's modeling of other wastes that appear to pose a greater hazard
suggest that the risks posed by the treated residue are low. For all of these reasons, EPA has concluded that
the potential for treated residue from roasting/leaching of chrome ore to pose significant risk to human health
or the environment is moderate to low. (See sections 4.3.3 and 4.7 for additional discussion.) Therefore, the
Agency has not conducted a quantitative risk modeling exercise for this waste.
4.3.2 Damage Cases
State and EPA regional files were reviewed in an effort to document the performance of waste
management practices for treated residue from the roasting/leaching of chrome ore. The file reviews were
combined with interviews with Texas and North Carolina State and EPA regional regulatory staff. Through
these case studies, EPA found no documented environmental damages attributable to management of the
treated residue from chrome ore processing. Ground-water contamination has been identified at the American
Chrome and Chemical facility, but it is not clear to what extent current waste disposal practices, historical
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Chapter 4: Sodium Dichromate Production 4-9
waste disposal practices (which involved management of an untreated residue), and/or neighboring facilities
are the source of the contamination.
Contacts with State agencies and review of State files also revealed that historical management
practices of the untreated chrome ore processing residues have created numerous sites where remediation (by
removal or other means) is planned or in progress.17 Examples include: (1) the Allied Chemical plant in
Baltimore, MD; (2) the city of Baltimore's Patapsco \tostewater Treatment Plant and other sites on Baltimore
Harbor where untreated chrome ore residues from the Allied Chemical facility were used as fill material; and
(3) more than 100 sites in Hudson County, New Jersey (includes Jersey City, Kearny, and Secaucus), where
use of the untreated residues (from three facilities - Allied Chemical Corp., PPG Industries, and Diamond
Shamrock Co.) in an urban setting resulted in chromium contamination of surficial soil, with associated
contamination of ground and surface water, sediment, building walls, and ambient air.
4.3.3 Findings Concerning the Hazards of Treated Residue from Roasting/
Leaching of Chrome Ore
Review of the available data on treated residue indicates that none of the waste's constituents are
present at levels above the screening criteria in samples of the treated residue solids. The available data also
indicate that the treated residue does not exhibit any of the four characteristics of hazardous waste. Data on
constituent concentrations in laboratory leachate from the treated residue indicate that concentrations of
chromium, vanadium, aluminum, manganese, and arsenic occur above screening criteria. None of the
constituents, however, are present at a concentration more than five times a screening criterion, and arsenic
is present at a concentration that is just equal to its human health screening criterion. Given the very
conservative nature of these screening criteria, these low contaminant concentrations in leachate from the
treated residue would pose a significant risk only under extreme exposure conditions.
The potential for release, transport and exposure is notably different at the two currently active
facilities. The ground-water release potential is high at the North Carolina facility and moderate at the Texas
facility, but the potential for risks resulting from drinking water exposure is low at both facilities because of
the low concentration of the leachate and because any contaminated ground water is likely to discharge directly
into adjacent surface waters without being withdrawn for drinking. At the North Carolina facility, it is unlikely
that release to surface waters via overland flow would occur, but migration through ground water that
discharges to surface water could occur. No significant impacts would be expected, however, due to the large
flow of the river. At the Texas plant, erosion to surface waters should be mitigated by run-off controls, but
releases through ground-water discharge to the Corpus Christi Shipping Channel could potentially occur. The
shipping channel contains saltwater, and comparison of leachate concentrations to the screening criteria did
not indicate any potential impacts to saltwater ecosystems. No constituents of potential concern were
identified for releases to air.
Based on the relatively low intrinsic hazard of the waste, the low potential for release, transport, and
exposure, and the absence of documented cases of danger to human health or the environment, EPA has
tentatively concluded that the hazard posed by treated residue from the roasting/leaching of chrome ore is
relatively low. Accordingly, only limited discussions of current applicable regulatory requirements, alternative
waste management and utilization, and costs and impacts are provided below.
17 EPA has previously determined that untreated chromium roast/leach ore residue is not a low hazard waste and, therefore, it is not
within the scope of this Report to Congress. (See 54 FR 36592, September 1,1989.)
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4-10 Chapter 4: Sodium Dichromate Production
4.4 Existing Federal and State Waste Management Controls
4.4.1 Federal Regulation
Although there are a number of Federal statutes and regulations which apply to various industrial
wastes generally (including those from ore mining and dressing and certain types of primary metal production),
there are none that specifically address solid wastes from chrome ore processing. It should be noted, however,
that untreated roast/leach residue and any additional wastes generated by chrome processing operations that
may exhibit a characteristic of hazardous waste are subject to Subtitle C of RCRA, as of the effective date
(July 23, 1990) of the final rule establishing the boundaries of the Mining Waste Exclusion (55 FR 2322,
January 23, 1990).
4.4.2 State Regulation
The nation's two chromium facilities are located in two states, North Carolina and Texas, both of
which were selected for regulatory review for the purposes of this report (see Chapter 2 for a discussion of
the methodology used to select states for detailed regulatory study). Both North Carolina and Texas have
adopted the federal exclusion from hazardous waste regulation for mineral processing wastes.
North Carolina does not regulate roasting/leaching residue from chrome ore under its solid waste
regulations, but does address this waste under state water pollution control regulations. North Carolina has
an approved NPDES program and requires that its single chromium facility maintain a "no discharge" permit
for the impoundments used for settling and disposing of the treated residue. Under the terms of this permit,
the facility must undertake activities such as weekly EP-toxicity testing, ground-water monitoring, and
personnel certification. The permit also stipulates that a closure plan must be submitted for approval three
months prior to closure of the impoundment. Finally, the facility's impoundment used for the disposal of
treated roasting/leaching ore residue is not subject to specific requirements in the facility's air permit, though
a recently promulgated toxic air pollutants regulation may result in the application of more stringent
requirements.
Texas classifies roast/leach residue from chrome ore as industrial solid waste. Because the chromium
facility in Texas disposes of its roast/leach ore residue on land that is both within 50 miles of the facility and
controlled by the facility owner/operator, the state has not required that the facility obtain a solid waste
disposal permit The facility is required to notify the state of its waste management activities, however, and
may be required to submit additional information such as waste characterization data. Moreover, all discharges
to surface water in the state must be permitted under both federal NPDES and state water quality discharge
permits. Finally, although the single chromium facility in Texas maintains an air permit, the permit does not
specifically address the roasting/leaching residue surface impoundments managed at the facility.
In summary, both of the states with chromium facilities, North Carolina and Texas, regulate the
chrome ore roasting/leaching residues generated at those facilities under solid waste and/or water quality
regulations. Of the two states, North Carolina appears to be somewhat more comprehensive in the kinds of
environmental controls required and the stringency of those controls. Finally, neither of the facilities' state-
issued air permits specifically address, at this time, the roasting/leaching residue management and disposal
units used by the facilities, though North Carolina may impose more stringent requirements under newly
promulgated toxic air pollutants regulation.
4.5 Waste Management Alternatives and Potential Utilization
As noted above, while the treated residue from roasting/leaching of chrome ore could pose a risk
under a very conservative set of conditions, the risk analysis indicates that significant impacts are unlikely.
Consequently, the issue of how sodium dichromate producers might modify their operations or waste
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Chapter 4: Sodium Dichromate Production 4-11
management practices or be stimulated to develop alternative uses for the treated roast/leach residue in
response to prospective hazardous waste regulation is not applicable. Nevertheless, EPA did search the
literature for information on research into alternatives for disposal and potential utilization of the treated
residue, but no relevant information was identified.
4.6 Cost and Economic Impacts
Because the available data indicate that treated residue from roasting/leaching of chrome ore does
not exhibit any of the characteristics of hazardous waste and is unlikely to pose significant risks to human
health and the environment, the issue of how waste management costs might change because of new
requirements associated with regulation under RCRA Subtitle C and what impacts such costs might impose
upon affected facilities has not been investigated.
4.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) potential for and documented
danger to human health and the environment; (2) the need for and desirability of additional regulation; and
(3) the costs and impacts of potential Subtitle C regulation.
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of the treated residue from roasting/leaching of chrome ore is relatively low
compared to other mineral processing wastes studied in this report. The treated residue does not exhibit any
of the four characteristics of hazardous waste. Data on constituent concentrations in solid samples of the
waste also do not indicate any exceedance of the screening criteria used in this analysis. Data on constituent
concentrations in laboratory leachate from the treated residue, however, indicate that five constituents are
present in concentrations above the conservative screening criteria. However, none of these constituents are
present at a concentration more than five times the screening criterion, and given the conservative nature of
these screening criteria, these low contaminant concentrations in leachate from the treated residue would pose
a significant risk only under extreme exposure conditions.
In addition to the relatively low intrinsic hazard of this waste, current management of the waste at
the facilities in North Carolina and Texas appears to limit the potential for the waste to threaten human
health or the environment. Although the ground-water release potential is relatively high at the North
Carolina facility and moderate at the Texas facility, the potential for exposure resulting from drinking water
is low at both facilities because of the low concentrations of the waste leachate and because any contaminated
ground water is likely to discharge directly into adjacent surface waters without being withdrawn for drinking
(i.e., the waste management units are located very near surface waters and it is unlikely ground water would
be withdrawn between the management units and the point of discharge into the surface water). At the North
Carolina facility, releases to surface waters via overland flow are unlikely, and releases through ground-water
discharge would not be expected to produce significant impacts because of the large flow of the river adjacent
to the plant. At the Texas plant, overland releases to surface waters would be mitigated by run-off controls,
and no adverse impacts are expected in the event of ground-water discharges to the adjacent saltwater system
because constituent concentrations in leachate from the treated residue are below concentrations that threaten
saltwater organisms.
The lack of documented cases of damage caused by the treated residue confirms that the waste, as
currently managed, appears not to cause significant health or environmental impacts. Review of State and
EPA Regional files and interviews of State and EPA Regional regulatory staff did not produce any evidence
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4-12 Chapter 4: Sodium Dlchromate Production
of documented environmental damages attributable to management of treated residue at the Texas or Nonh
Carolina facilities.
Likelihood That Existing Risks/Impacts Will Continue in the
Absence of Subtitle C Regulation
The relatively low intrinsic hazard of the waste and the current waste management practices and
environmental conditions that currently limit the potential for significant threats to human health and the
environment are expected to continue to limit risks in the future in the absence of Subtitle C regulation. The
characteristics of this waste are unlikely to change in the future, and despite the fact that this analysis is
limited to the two sites at which the waste is currently managed, EPA believes that the conclusion of low
hazard can be extrapolated into the future because the environmental conditions in which the waste is
managed are unlikely to change. Management of treated residue is unlikely to expand beyond the two
locations currently in use for three reasons. First, the quantity of material involved makes it unlikely that the
treated residue from roasting/leaching of chrome ore would be removed from the impoundments for disposal
elsewhere. Second, current trends in industry growth indicate that construction of additional sodium
dichromate production facilities is not likely. Third, the treated roast/leach residues have historically not been
used off-site, and no viable approaches to utilization of the treated residue have been identified.
At the facility in Nonh Carolina, the potential for increased risks in the future is further restricted
by substantial State regulation of the treated residue disposal unit. The requirements for this unit, which are
incorporated in a state-administered water quality permit, include no discharge from the impoundments used
for settling and disposal of the treated residue, weekly EP-toxicity testing, ground-water monitoring, a
compliance boundary where water quality standards must be met, and operation of the unit by a certified
operator. At the Texas facility, in contrast, the State's application of environmental control requirements for
waste management activities is limited.
Costs and Impacts of Subtitle C Regulation
Because of the low risk potential of treated residue from roasting/leaching of chrome ore, the general
absence of documented damages associated with this material, and the fact that this waste does not exhibit any
characteristics of hazardous waste, EPA has not estimated the costs and associated impacts of regulating
treated residue from roasting/leaching of chrome ore under RCRA Subtitle C.
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Chapter 5
Coal Gasification
The domestic coal gasification industry presently consists of one facility that, as of September 1989,
was the only commercial coal gasification plant in full operation in the United States1 that reported
generating two special mineral processing wastes: gasifier ash and process wastewater. The data included in
this chapter are discussed in additional detail in a technical background document in the supporting public
docket for this report.
5.1 Industry Overview
The coal gasification facility produces synthetic natural gas that is sent to a refinery for processing
as a natural gas for energy production. The Great Plains Coal Gasification Plant is located in Beulah, Mercer
County, North Dakota and is owned and operated by the Dakota Gasification Company. The Great Plains
facility began operation in 1984. The facility reported an annual capacity of 1.1 million metric tons in 1988,
and an actual production of 1.0 million metric tons of natural gas.
The Great Plains plant set a new annual production record for 1989 with a 9.8 percent increase over
its 1988 level and a 5.1 percent increase over 1987 production.2 The profitability of existing facilities and the
potential for the opening of new plants will be affected by the prices of alternative fuel sources such as oil and
gas.
The facility employs 12 Lurgi Mark IV high pressure coal gasifiers, with two gasifiers on standby for
spare capacity. The overall coal gasification process is illustrated in Exhibit 5-1. Lignite coal, which is taken
from four mines that are co-located with the facility, is crushed and fed to the top of individual gasifiers
through a lock-hopper system; steam and compressed oxygen are introduced at the bottom of each gasifier.
As the coal charge descends through the gasifier bed, it is dried, devolatilized, and gasified. The ash remaining
in the bed after the reaction is removed by a rotating grate at the bottom of the gasifier and is discharged
through a gas lock. The ash is discharged into an enclosed ash sluiceway, where recirculating ash sluice water
is introduced to cool the ash and transport it to the ash handling and disposal area. The hot crude product
gas leaving the gasifiers goes through several operations, including quenching (to cool and clean), shift
conversion (to alter the ratio of hydrogen to carbon monoxide), further cooling of the gas, and processing
through the Rectisol unit (to remove sulfur compounds and carbon dioxide). The desulfurized crude gas is
sent to the methanation unit; the product gas is then compressed and dried for delivery to a pipeline for
distribution.3
The quenching operation described above, in addition to cooling the raw gas, serves to remove
entrained particles from the gas and to condense and remove unreacted steam, organic compounds, and soluble
gases. The result of this cooling operation is an aqueous stream known as quench liquor. This process stream,
along with similar streams from the shift conversion, gas cooling, and rectisol units, are sent to the gas liquor
separation unit (for removal of tar and oil), to a phenosolvan unit (for phenol recovery), and to a phosam-W
1 EPA is tware of two other facilities that conduct commercial-scale coal gasification operations. These plants, located at Daggett,
California and Placamine, Louisiana, employ a different technology than that used at the Beulah, North Dakota facility that is the subject
of this chapter. The facility in California has been inactive since early 1988 and is currently being overhauled so that it can burn a mixture
of 75 percent coal and 25 percent sewage sludge. The Louisiana facility is currently operating and gasifies about 2,400 tons per day of
coal. EPA is continuing to collect information on waste generation, management practices, and process operations at these facilities to
determine if the regulatory determination will apply to any wastes generated by these facilities.
2 The Bulletin," 1990. Great Plains Synfuels-Dakota Gasification Company, Volume 7, No. 3, January 16, p. 4.
3 Environmental Protection Agency, 1987. American Natural Gas Special Study. Prepared by COM for the U.S. EPA, Washington,
D.C., March, 1987; pp. 14-27.
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5-2 Chapter 5: Coal Gasification
Exhibit 5-1
Coal Gasification
Beneficiated
PROCESS
SPECIAL WASTE
MANAGEMENT
Menthanotion ^ °s
& Compression ^ to
Pipeline
Legend
Production Operation
Special Waste
o
Waste Management Unit
ammonia recovery unit (for ammonia recovery). The process water leaving the phosam-W unit, known as
stripped gas liquor, is the special waste, coal gasification process wastewater. This process wastewater is used
as make-up water for a water cooling system that is needed to cool the gasifiers during operation. The hot
water is routed to a cooling tower used to remove heat from the system. The evaporation from the cooling
tower exceeds the quantity of stripped gas liquor generated on an annual basis; hence, all stripped gas liquor
is used as make-up water.
5.2 Waste Characteristics, Generation, and Current Management Practices
The coal gasification operation discussed in this report generates both a solid special mineral
processing waste, gasifier ash, and an aqueous process waste, stripped gas liquor.
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Chapter 5: Coal Gasification 5-3
Gasifier Ash
Gasifier ash, which reportedly has a particle size ranging from two millimeters to eight centimeters
in diameter (gravel), is composed primarily of sulfate, calcium, silicon, sodium, aluminum, and magnesium.
The Dakota gasification facility reported generating 245,000 metric tons of gasifier ash in 1989.
Using available data on the composition of coal gasification gasifier ash, EPA evaluated whether the
ash exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and
extraction procedure (EP) toxicity. Based on professional judgment and analyses of 59 gasifier ash samples
from the Beulah facility, the Agency does not believe the ash is corrosive, reactive, ignitable, or EP toxic.
Gasifier ash that is removed from the bottom of the gasifier is quenched, passed through crushers to
reduce the maximum size to eight centimeters, then sluiced into ash sumps for settling and dewatering. The
dewatered ash is trucked to an on-site clay-lined landfill, where it is disposed along with ash from boilers,
superheaters, and incinerators, and settled solids from process water management units (e.g., impoundments,
API separators).
The landfill is 23 meters (75 feet) deep with an area of 4.9 hectares (12 acres) and is lined with
recompacted clay. Although the landfill receives a variety of wastes, the ash accounts for approximately 95
percent of the total input. Material is typically not removed from the landfill and the remaining life is five
years. A total of 1,500,000 metric tons4 of combined solids has accumulated at the solid waste disposal site,
approximately 95 percent of which is assumed to be gasifier ash based on Survey responses.
Process Wastewater
The process wastewater has an average pH of 9.8 and a solids content of approximately 0.2 percent.
The principal contaminant in the water reportedly is NO3, with additional trace amounts of chlorides, sodium,
phenols, and oil and grease. The Dakota gasification facility reported generating 4.83 million metric tons of
process wastewater during 1988.
Using available data on the composition of coal gasification process wastewater, EPA evaluated
whether the wastewater exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity,
ignitability, and extraction procedure (EP) toxicity. Based on professional judgment and analyses of two
process wastewater samples from the Beulah facility, the Agency does not believe the wastewater exhibits any
of these characteristics. Using the EP leach test, for example, all of the inorganic constituents with EP toxicity
regulatory levels, except selenium, were measured in concentrations that were at least two orders of magnitude
below the regulatory level; the maximum observed concentration of selenium in EP leachate was 0.4 times the
regulatory level.
The process wastewater (i.e., stripped gas liquor) is used as make-up water for the gasifier water-
cooling system. In this system, large quantities of water are lost to evaporation (3,000-3400 gpm, or 6-7
million metric tons per year) from the cooling tower. Evaporation losses are made up using primarily the
stripped gas liquor, as well as softened ground water and other on-site wastewaters. Although the quantity
of water lost from the gasifier cooling system through evaporation exceeds the quantity of process wastewater
generated on an annual basis, the supply of process wastewater generated on a daily basis sometimes exceeds
the need for cooling system make-up water. When this occurs, a surge pond is used to store the process
wastewater until it is needed. This impoundment, which is lined with recompacted local clay and a 36 mil
synthetic liner, has an area of about 4.3 hectares (11 acres) and a depth of 4 meters (13 feet). No long-term
accumulation of waste occurs in this unit; the water is pumped to the cooling tower and settled solids are
dredged (approximately 13 metric tons in 1988) and sent to the solid waste disposal landfill.
4 Quantity was originally reported in cubic yards (960,000 cubic yards). This was convened to metric tons assuming a specific gravity
of 2.0 for the ash sludge.
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5-4 Chapter 5: Coal Gasification
The evaporation of water, from the cooling water system results in any impurities in the make-up
water being concentrated in the remaining cooling system water; these impurities can lead to scaling or other
operational problems in the system. Therefore, the cooling water in the system is bled off at a rate of 360-500
gpm to prevent concentration of impurities from reaching unacceptable levels. This concentrated bleed, known
as cooling tower blowdown, was generated at a rate of approximately 766,000 metric tons in 1988.
This cooling tower blowdown and the residuals from the treatment of the waste stream are not special
wastes (because they are not large volume wastes), but the management of these streams is discussed briefly
to provide an overview of the operation. The cooling tower blowdown is treated in a multiple effects
evaporator (MEE) unit. Distillate from this treatment is returned to the cooling system or used as other
facility utility water. The remaining residual, MEE concentrate, is returned as feed to the gasifier or is sent
to an on-site liquid waste incinerator (LWI). Separate surge ponds are used for storage of MEE distillate and
concentrate. The waste stream from the LWI unit, referred to as LWI blowdown, is sent to the coal ash sluice
area to be included as make-up water for ash handling. Any incinerator ash/solids in the blowdown are,
therefore, combined with the gasifier ash and managed as such.5
5.3 Potential and Documented Danger to Human Health and the Environment
This section addresses two of the study factors required by §8002(p) of RCRA: (1) potential danger
(i.e., risk) to human health and the environment; and (2) documented cases in which danger to human health
or the environment has been proven. Overall conclusions about the hazards associated with coal gasifier ash
and process wastewater are provided after these two study factors are discussed.
5.3.1 Risks Associated with Gasifier Ash and Process Wastewater
Any potential danger to human health and the environment from coal gasifier ash and process
wastewater depends on the presence of toxic constituents in the wastes that may pose a risk and the potential
for exposure to these constituents.
Constituents of Potential Concern for Coal Gasification Gasifier Ash
EPA identified chemical and radiological constituents in coal gasifier ash that may present a hazard
by collecting data on the composition of the waste and evaluating the intrinsic hazard of the ash's constituents.
Dafa on Coal Gasifier Ash Composition
EPA's characterization of the gasifier ash and its leachate is based on data from a 1989 sampling and
analysis effort by EPA's Office of Solid Waste (OSW) and industry responses to a RCRA §3007 request in
1989. These data provide information on the concentrations of 20 metals, radium-226, uranium-238, gross
alpha and beta radiation, cyanide, a number of other inorganic constituents (i.e., phosphate, fluoride, and
sulfate), and 30 semivolatile and volatile organic constituents in total and leach test analyses.
Concentrations in total samples of the ash are consistent for most constituents across the two data
sources. Likewise, concentrations from leach test analyses of the gasifier ash generally are consistent across
the two data sources. Among EP results, however, arsenic, barium, chromium, and silver concentrations vary
by more than two orders of magnitude. In addition, maximum leachate concentrations of many constituents
(i.e., arsenic, barium, cadmium, chromium, copper, lead, manganese, selenium, and silver) detected in EP leach
tests are approximately 10 times higher than concentrations detected by SPLP or TCLP analyses. Conversely,
5 As reported by Dakota Gasification Company, approximately 32,000 metric tons of LWI blowdown was generated in 1988 with a
solids content of 5 percent; these approximately 1,600 metric tons of solids are assumed to be included in the total volume of gasifler ash
reported by the company.
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Chapter 5: Coal Gasification 5-5
concentrations of aluminum, iron, uranium-238, and vanadium detected by SPLP analyses are greater than
approximately five times the highest EP and TCLP concentrations.
Process for Identifying Constituents of Potential Concern
As discussed in Section 2.2.2, the Agency evaluated the waste composition data summarized above
to determine if coal gasifier ash contains any chemical constituents that could pose an intrinsic hazard, and
to narrow the focus of the risk assessment. The Agency performed this evaluation by first comparing
constituent concentrations to the screening criteria, and then by evaluating the environmental persistence and
mobility of constituents that are present in concentrations that exceed the criteria. These screening criteria
were developed using assumed scenarios that are likely to overestimate the extent to which constituents in the
wastes are released to the environment and migrate to possible exposure points. As a result, this process
eliminates from further consideration those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic organisms, and air and water resources (see Exhibit 2-3). Given the conservative (i.e., overly
protective) nature of these screening criteria, contaminant concentrations in excess of the criteria should not,
in isolation, be interpreted as proof of hazard. Instead, exceedances of the criteria indicate the need to
evaluate the potential hazards of the waste in greater detail.
Identified Constituents of Potential Concern
Exhibits 5-2 and 5-3 present the results of the comparisons for gasifier ash total analyses and leach
test analyses, respectively, to the screening criteria. These exhibits list all constituents for which sample
concentrations exceed a relevant screening criterion.
Of the 58 constituents analyzed in the ash solids, only uranium-238, thallium, arsenic, and chromium
concentrations exceed the screening criteria. Among these constituents, uranium-238, thallium, and arsenic
exceed the screening criteria with greater frequency and magnitude. However, only arsenic is present at a
concentration that exceeds a screening criterion by a factor of more than 10. These exceedances of the
screening criteria indicate the potential for a variety of impacts, as follows:
Exhibit 5-2
Potential Constituents of Concern In Coal Gas Ash Solids(a)
Potential Constituent*
of Concern
Uranium-238
Thallium
Arsenic
Chromium
No. of Time* Constituent
Detected/No, of Analyses
: 1/t
3/3
3/5
4/4
Human Health
Screening Criteria***
Inhalation*
Radiation***
Ingestion
tngestion*
Inhalation*
Inhalation*
No. of Analyses
Exceeding Criteria/No, of
Analyses for Constituent
1/1
1/1
2/3
3/5
3/5
1/4
(a) Constituents listed in this table are present in at least one sample at a concentration that exceeds a relevant screening
criterion. The screening criteria values are shown in Exhibit 2-3. Constituents that were not detected in a given sample
were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10"5 lifetime
cancer risk; others are based on noncancer effects.
(c) Includes direct radiation from contaminated land and inhalation of radon decay products.
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5-6 Chapter 5: Coal Gasification
Exhibit 5-3
Potential Constituents of Concern In Coal Gas Ash Leachate^
Potential Constituents
of Concern
Arsenic
Lead
Silver
Selenium
Mercury
Chromium
Sulfate**
Aluminum'0'
Molybdenum
Barium
No. of Times Constituent
Detected/No, of Analyses
for Constituent
35/59
27/59
7/58
19/59
7/59
10/59
1/1
2/2
3/3
49/59
Screening Criteria"4
Human Health*
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Resource Damage
No. of Analyses
Exceeding Criteria/No, of
Analyses for Constituent
35/59
4/59
2/59
10/59
27/59
5/59
1/58
1/58
7/58
2/59
2/59
5/59
1 /59
1 /59
1/1
2/2
3/3
2/59
Constituents listed In this table are present in at least one sample at a concentration that exceeds a relevant screening
criterion. The screening criteria values are shown in Exhibit 2-3. Constituents that were not detected in a given sample
were assumed not to be present in the sample. Unless otherwise noted, the constituent concentrations used for this
analysis are based on EP leach test results.
Human health screening criteria are based on cancer risk or noncancer health effects. 'Human health' screening
criteria noted with an '*' are based on 1x10"5 lifetime cancer risk; others are based on noncancer effects.
Data for this constituent are from SPLP tost results.
Uranium-238 concentrations exceed the radiation screening criterion by a factor of
almost 4, suggesting that the ash could pose an unacceptable radiation risk if the ash
were used in an unrestricted manner (e.g., direct radiation doses and doses from the
inhalation of radon could be unacceptably high if people were allowed to build homes
on top of the ash or if the ash were used for construction purposes).
Uranium-238, arsenic, and chromium concentrations in the ash may be present in
concentrations that exceed the inhalation screening criteria. This suggests that if small
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Chapter 5: Coal Gasification 5-7
panicles from the ash are blown into the air in a high concentration (equal to the
National Ambient Air Quality Standard for particulate matter), chronic inhalation of
these constituents could cause a cancer risk exceeding 10~5. As discussed in the section
on release/transport/exposure potential, however, such large exposures to windblown
particles are generally not expected at the Beulah facility.
• Thallium and arsenic may be present in the ash at concentrations that exceed the
incidental ingestion screening criterion, suggesting that these constituents could pose
health risks if small quantities of the ash are routinely ingested over a long period of
time (i.e., more than about seven years). Arsenic concentrations could pose a cancer
risk of greater than IxlO"5, while thallium concentrations could cause adverse central
nervous system effects.
Of the 24 constituents analyzed in the leach tests, the following 10 constituents are present at
concentrations that exceed the screening criteria based on water pathway risks: arsenic, lead, silver, selenium,
mercury, chromium, sulfate, aluminum, molybdenum, and barium. All of these constituents are inorganics that
do not degrade in the environment. Arsenic, silver, and lead are of relatively greater concern because their
concentrations in the ash leachate exceed the screening criteria with the greatest frequency and magnitude.
Arsenic concentrations exceeded the human health (drinking water) screening criterion in almost 60 percent
of the samples analyzed; the median arsenic concentration exceeded the criterion by a factor of 8, and the
maximum exceeded by a factor of 1,100. Silver concentrations exceeded the aquatic ecological screening
criterion in 12 percent of the samples, and the maximum silver concentration exceeded the criterion by a factor
of 370. No other constituents are present in concentrations that exceed screening criteria by a factor of 10.
In addition, no constituents were detected in concentrations that exceed the EP toxicity regulatory levels.
These exceedances of the screening criteria indicate the potential for the following types of effects
under the following conditions:
• If leachate from the ash were released to ground or surface water, and diluted less than
tenfold during migration to a drinking water source, long-term chronic ingestion may
cause adverse health effects due to the presence of arsenic, lead, and silver. The arsenic
concentrations in the diluted ash leachate may pose a significant (i.e., >lxlO*5) lifetime
cancer risk if ingested.
• Coal gasifier ash leachate contains arsenic, lead, silver, selenium, chromium, sulfate,
molybdenum, and barium in concentrations that exceed the water resource damage
screening criteria. This suggests that if leachate from the ash is released and migrates
into ground or surface water with a tenfold dilution or less, the resulting concentrations
of these constituents may be sufficient to restrict the potential future uses of the
affected water (e.g., render stream water unsuitable for irrigation or for drinking water
supply unless treated).
• Arsenic, lead, silver, selenium, mercury, chromium, and aluminum concentrations in the
ash leachate exceed the aquatic ecological screening criteria, suggesting that these
constituents may present a threat to aquatic ecological receptors if the leachate migrates
(with less than 100-fold dilution) to streams, rivers, or lakes.
These exceedances of the screening criteria, by themselves, do not demonstrate that the ash poses a
significant risk, but rather indicate that it may present a hazard under a very conservative, hypothetical set of
release, transport, and exposure conditions. To determine the potential for the ash to cause significant
impacts, EPA analyzed the actual conditions that exist at the sole facility that generates and manages the waste
(see the following section on release, transport, and exposure potential).
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5-8 Chapter 5: Coal Gasification
Coal Gasification Process Wastewater Constituents of Potential Concern
Using the same process summarized above for gasifier ash, EPA identified constituents in coal
gasification process wastewater that may present a hazard by collecting data on the composition of this waste,
and evaluating the intrinsic hazard of the chemical constituents present in the process wastewater.
Data on Coal Gasification Process Wastewater Composition
EPA's characterization of the process wastewater and its leachate is based on data from a 1989
sampling and analysis effort by EPAs Office of Solid \Vkste (OSW) and industry responses to a RCRA §3007
request in 1989. These data provide information on the concentrations of 20 metals, a number of other
inorganic constituents (i.e., ammonia, ortho-phosphate, and phosphorus), and 159 organic constituents in total
and leach test analyses.
Concentrations in total sample analyses of the process wastewater are consistent for most constituents
across the two data sources. For antimony, however, the results differ significantly. EPA did not detect
antimony in the wastewater at a detection limit of 0.025 mg/L while industry data show antimony to be present
at concentrations almost five orders of magnitude higher. Concentrations from the two types of leach test
analyses (i.e., EP and SPLP) of the process wastewater generally are similar. However, EP leach test data from
the two sources --1989 OSW sampling and analysis and industry response to the RCRA §3007 request — differ
considerably (no SPLP data were provided by industry). Among the eight constituents for which EP leach test
data are available from EPA and industry, four constituents (i.e., arsenic, chromium, mercury, and selenium)
are detected in EPA analyses at concentrations that are one or two orders of magnitude higher than in
industry analyses.
The following evaluation of constituents in the process wastewater is based on concentrations detected
in total analyses of the wastewater. Leach test analyses are generally similar to total analysis results, although
a smaller number of constituents in concentrations above the screening criteria are identified in the leachate
(possibly because of the filtration step involved in leach test analyses). Several of the inorganic constituents
with EP toxicity regulatory levels (arsenic, cadmium, chromium, lead, mercury, and selenium) were measured
in higher concentrations in total analyses than leach test analyses.
Identified Constituents of Concern
Exhibit 5-4 presents the results of the comparisons of coal gasification process wastewater constituent
concentrations to the screening criteria. This exhibit lists all constituents for which at least one sample
concentration exceeds a relevant screening criterion.
Of the 182 constituents analyzed in the process wastewater, only 19 are present at concentrations that
exceed the screening criteria: phosphorus, phosphate, antimony, mercury, arsenic, thallium, molybdenum,
selenium, nickel, iron, copper, manganese, lead, cadmium, cobalt, chromium, acetonitrile, phenol, and pH.
Seven of these - phosphorus, phosphate, antimony, mercury, arsenic, thallium, and phenol - were present in
concentrations in the process wastewater that exceed the screening criteria with greatest frequency and
magnitude (i.e., maximum concentrations of these constituents exceed a screening criterion by more than a
factor of 10, and more than one-third of all samples analyzed for the constituent exceed the criterion). None
of the constituents, however, were detected in concentrations above the EP toxicity regulatory levels, and the
wastewater does not exhibit the hazardous waste characteristics of corrosivity, ignitability, or reactivity.
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Chapter 5: Coal Gasification 5-9
Exhibit 5-4
Potential Constituents of Concern In Coal Gas Process Waste water (total)(a)
Potential Constituent*
of Concern
Phosphorous
Phosphate
Antimony
Mercury
Arsenic
Thallium
Molybdenum
Selenium
Nickel
Iron
Copper
Manganese
Cobalt
Lead
Cadmium
Chromium
Acetonftrite
Phenol
PH
No. of Time* Constituent
Detected/No, of Analyses
for Constituent
1/1
1/1
2/3
5/6
3/8
2/3
2/3
5/8
2/3
3/3
3/3
3/3
2/3
2/8
2/8
9/10
2/2
2/2
'"
Screening Criteria*1"
Aquatic Ecological
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Human Health*
Resource Damage
Human Health
Resource Damage
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Human Health
Resource Damage
Resource Damage
No. of Analyses
Exceeding Crrteria/No. of
Analyses for Constituent
2/2
1/1
2/3
2/3
2/3
1/6
5/6
3/8
2/8
2/3
2/3
5/8
1/8
1/3
1/3
2/3
2/3
2/3
1/3
1/3
1/8
2/8
1/8
1/8
1/8
1/8
1/10
2/2
2/2
1/1
(a) Constituents listed in this table are present in at least one sample at a concentration that exceeds a relevant screening
criterion. The screening criteria values are shown in Exhibit 2-3. Constituents that were not detected in a given sample
were assumed not to be present in the sample.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. 'Human hearth* screening
criteria noted with an '*' are based on 1x10"* lifetime cancer risk; others are based on noncancer effects.
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5-10 Chapters: Coal Gasification
These exceedances of the screening criteria have the following implications:
• Antimony, arsenic, thallium, acetonitrile, nickel, lead, and cadmium may be present in
seepage from the process wastewater surge pond at concentrations that exceed the
human health screening criteria. This suggests that if the wastewater is released to
useable ground or surface water, these constituents could cause adverse human health
effects via long-term chronic ingestion of drinking water, if it is diluted by only a factor
of 10 during migration to drinking water supplies. Exposures to arsenic in the diluted
leachate could pose a lifetime cancer risk of greater than IxlO'5.
• Phenol, antimony, mercury, arsenic, molybdenum, selenium, nickel, iron, manganese,
lead, cadmium, cobalt, and chromium are present in the process wastewater at
concentrations that exceed the water resource damage screening criteria. This indicates
that if the wastewater migrates into ground water with less than a 10-fold dilution or
migrates into surface water with less than a 100-fold dilution, the resulting con-
centrations of these contaminants could render the water resources unsuitable for a
variety of uses (e.g., drinking water, livestock watering, irrigation, consumption of fish
that live in contaminated water bodies). The wastewater is also alkaline (pH 10) and
could threaten water resources if it were to raise the pH of receiving waters to above
8.5 standard units.
• If process wastewater were released to nearby surface waters (with less than 100-fold
dilution), phosphorus, phosphate, antimony, mercury, selenium, nickel, copper, lead, and
cadmium could pose a risk to aquatic life.
As discussed above for coal gas ash, these exceedances of the screening criteria, by themselves, do not
demonstrate that the process wastewater poses a significant risk, but rather indicate that the wastewater may
present a hazard under a very conservative, hypothetical set of release, transport, and exposure conditions.
To determine the potential for the wastewater to cause significant impacts, EPA proceeded to the next step
of the risk assessment to analyze the actual conditions that exist at the facility that generates and manages the
waste.
Release, Transport, and Exposure Potential
This section describes the actual release, transport, and exposure potential of the coal gasification
wastes as they were generated and managed at the Beulah plant in 1988. For this analysis, the Agency did not
assess the hazards of off-site use or disposal of the wastes, because the wastes are currently managed only on-
site (although it is conceivable that ash with certain properties could be used off-site in the future in the
manufacture of cement or concrete products). In addition, the following analysis does not consider the risks
associated with variations in waste management practices or potentially exposed populations in the future
because of a lack of data on which to base forecasts of future conditions. Alternative practices for the
management of gasifier ash and process wastewater are discussed in Section 5.5.
Ground-Wafer Release, Transport, and Exposure Potential
The waste characterization data discussed above indicate that leachate from the waste ash contains
10 constituents at concentrations that exceed the conservative screening criteria. Similarly, the characterization
of the process wastewater identified 19 constituents that exceed the screening criteria. These wastes contain
from 2 to 7 constituents that exceed screening criteria related to ground water by factors of at least 10,
although no contaminants were detected in concentrations that exceed the EP toxicity regulatory levels. The
constituents in the waste ash leachate and process wastewater that are expected to be readily mobile in
groundwater are phosphorus, phosphate, mercury, molybdenum, selenium, cadmium, chromium, and sulfate.
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Chapter 5: Coal Gasification 5-11
Differences in the characteristics of the management units used to dispose of the gasifier ash and store
process wastewater contribute to substantial differences in the potential ground-water hazards posed by these
wastes as they are currently managed.
The gasifier ash landfill has a liner of recompacted local clay, but does not have any
other type of ground-water controls such as a leachate collection system.
• The surge pond that is used to temporarily store the process wastewater has multiple
engineered controls to limit seepage to ground water. This pond has a double liner --
comprised of separate layers of synthetic material and recompacted local clay -- and has
both primary and secondary leachate collection systems.
As a consequence of these controls, the potential for releases of process wastewater from the surge
pond is limited to a large extent, while the potential for releases from the landfill is higher. In fact, ground-
water monitoring data from the Dakota facility provides evidence that the ash landfill may be contributing to
ground-water degradation. The Dakota facility reported that drinking water standards for nitrate, sulfate,
chloride, pH, and total dissolved solids had been exceeded in downgradient monitoring wells. The facility
attributes these exceedances to possible ambient ground-water quality problems in this area; Section 5.3.2
provides further discussion of these monitoring data.
The hydrogeologic characteristics at the site indicate a potential for contaminants to migrate into
ground water: net recharge in the vicinity of the facility is moderate (10 cm/year), and ground water is very
shallow (0.3 to 0.6 meters beneath the landfill). These factors, in combination with the relatively high
leachability of the ash and the limited ground-water release controls at the landfill indicate a high potential
for contaminants to migrate from the ash landfill into underlying ground water. The controls on the surge
pond should significantly limit migration of the wastewater.
Although the facility reported that the aquifer underlying the facility is not being used for any
purpose, mapping data indicate that there are two residences between 900 and 1,600 meters (1 mile)
downgradient of the facility that appear to be located outside of areas covered by local water distribution
systems, and, therefore, may rely on private water sources (e.g., private wells). Consequently, leachate from
the landfill could damage the value of the aquifer as a potential resource, but the potential for current human
exposures is low because of the large distance (> 900 meters) to the small population (i.e., two residences)
that may rely on ground water downgradient of the site as a drinking water supply.
Surface Water Re/ease, Transport, and Exposure Potential
In theory, constituents from the gasifier ash in the landfill or process wastewater in the surge pond
could enter surface waters by (1) migration of leachate or seepage through ground water that discharges to
surface water or (2) direct overland run-off of dissolved or suspended materials from the landfill or surge pond.
The potential for release and transport of gasifier ash and process wastewater contaminants to surface
water appears limited by the relatively low precipitation in the area (37 cm/year), the presence of stormwater
run-off controls designed to limit erosion from the landfill and overflow of the surge pond, and the gentle
topographic slope (0 to 2 percent) that also limits erosion potential. In addition, while there is an on-site
stormwater diversion ditch and a nearby intermittent stream, the facility is far removed from perennial water
bodies that may be used: the nearest perennial stream is 10 km (6 miles) downslope and this stream
discharges into the Knife River approximately 15 km away. Because the facility is not located in or near a 100-
year floodplain, large episodic releases and subsequent overland transport due to flooding are also unlikely.
Despite these mitigating factors, releases to surface water from the ash landfill may have occurred.
As discussed in Section 5.3.2, a State of North Dakota Notice of Violation indicates that gasifier ash
management practices at this facility "probably resulted in some surface water degradation."* Although the
6 North Dakota State Department of Health and Consolidated Laboratories. 1987. Interdepartmental Memorandum from S. Tillotson
to B. Dellmorc, through M. Schock, Re: ANG Notice of Violation. 7/20/87.
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5-12 Chapters: Coal Gasification
notice does not clarify this statement, the degradation is likely confined to the on-site drainage ditch and
nearby intermittent stream, potentially caused by either stormwater run-off or discharge of contaminated
ground water from the landfill. These waters are unlikely to be used for human consumption, but any
contamination in them potentially could be harmful to aquatic organisms.
Should contamination from this site reach the distant Knife River or its tributary, either by overland
run-off or through ground-water infiltration, the relatively large annual average flow (600 mgd) of the river
could rapidly assimilate (dilute) the contamination. Consequently, contamination from gasifier ash and process
wastewater appear to pose a minimal threat to potential uses of the river or to its aquatic life. To the best
of the Agency's knowledge, no population currently relies on the river as a regular drinking water source in
the vicinity of the Dakota facility, and no current human health risks from drinking water exposures are
expected.
Air Release, Transport, and Exposure Potential
Air pathway risks from ash and process wastewater involve two different release pathways. The
constituents that exceed the screening criteria in gasifier ash ~ uranium-238, arsenic, and chromium -- are
nonvolatile inorganics that can be released to air only as wind-blown particles (dust). Acetonitrile and phenol
conceivably could pose inhalation risks through volatilization from the process wastewater. The concentrations
of these constituents in the wastes represent relatively low human health risks (as indicated by relatively low
ratios of the maximum concentrations to screening criteria).
Factors that determine the potential for inorganic constituents of the gasifier ash to be suspended in
air are the particle size of the ash, the exposed surface area of the landfill, the moisture content of the ash,
the use of dust suppression controls, and wind speeds in the vicinity of the facility. The potential for exposure
to airborne contaminants depends on the distances from the landfill to nearby residences and the population
in the area. In general, panicles that are <_ 100 micrometers (/im) in diameter are wind suspendable and
transportable. Within this range, however, only particles that are <. 30 urn in diameter can be transported
for considerable distances downwind, and only particles that are <. 10 /urn in diameter are respirable.
Although some fraction of the ash may exist as panicles that can be suspended in air and cause
airborne exposure and related impacts, the vast majority of the gasifier ash is comprised of panicles too large
to be suspended, transported, and respired. In addition to the generally large particle size, releases of the ash
are also limited by dust suppression practices and the moisture content of the ash as it is deposited in the
landfill. However, in the event that areas of the landfill surface become dry (e.g., if dust suppression is ceased
or provides incomplete coverage), a small fraction of the ash panicles could be blown into the air because of
the large exposed area (approximately 5 hectares [12 acres]), the relatively small number of days with rain that
may suppress dust (54 days/yr), and the strong winds in the area (4.5 to 6.7 m/s). After the small, near-surface
panicles are depleted, airborne emissions would again decline to low levels.
The ability of an organic constituent to volatilize from the wastewater depends on its Henry's Law
constant, which is a measure of the constituent's tendency to partition between water and air. A large Henry's
Law constant indicates a greater propensity for an organic compound to volatilize from water. Because
acetonitrile and phenol have relatively high Henry's Law constants, they may be released from the surge pond
by volatilization.
Evaluation of the location of potential exposure points indicates that the air pathway risks from these
wastes are relatively small. Winds at the Dakota facility blow most frequently in the WNW, W, S, WSW
directions. The nearest downwind residences in these directions are quite distant (i.e., 2.1, 1.5, 4.5, and 5.2
km, respectively) and the population within 8 kilometers (5 miles) in these directions is very sparse (i.e., 13,
18, 8, 18 people, respectively). The population within a radius of 80 km from the facility is approximately
40,000. Considering the low inorganic constituent concentrations relative to air pathway screening criteria,
the low potential for release of dust from the landfill, and the great dispersion of airborne contaminants (both
volatiles and particles) that would occur during transport to exposure points greater than one kilometer away,
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Chapter 5: Coal Gasification 5-13
there is a low potential for human exposure (and associated health risk) to dust blown from the ash landfill
or contaminants volatilized from the surge pond.
Proximity to Sensitive Environments
The coal gasification facility is not located in or near any environments that may facilitate
contaminant release and transport (such as floodplains, karst, and fault zones), that have high resource value
(such as National Parks), or environments that are especially sensitive to contaminant exposures (such as
wetlands and endangered species habitat).
Risk Modeling Results
Based upon the evaluation of the intrinsic hazard of gasifier ash and process wastewater, both wastes
contain a number of constituents in concentrations that may present a hazard under a very conservative set
of hypothetical release and exposure conditions. However, considering the actual conditions that exist at the
Beulah, ND facility, the potential for these wastes to cause significant human health or environmental impacts
is low. This conclusion is based on the following findings:
• Only arsenic and silver in coal gasifier ash and its leachate are present at concentrations
more than ten times the screening criteria; seven constituents in coal gas process
wastewater exceed the conservative screening criteria by a factor of 10 or greater; but
neither gasifier ash nor process wastewater exhibit any of the four characteristics of
hazardous waste.
• The potential for releases from the ash landfill and surge pond are limited by controls
such as liners, run-off controls, and dust suppression. Nevertheless, releases to ground-
and surface water from the ash landfill have occurred. The potential for exposures to
released contaminants at concentrations of concern is relatively low given the large
distances to nearby residences and perennially flowing surface water.
This conclusion is supported by the information on documented damage cases (presented in the next section)
and the Agency's risk modeling results for other wastes that appear to pose a greater hazard than the coal
gasification wastes. Therefore, in accordance with the risk assessment methodology outlined in Chapter 2, the
Agency has not conducted a quantitative risk modeling exercise for these wastes. Section 5.3.3 below discusses
the basis for the assessment of moderate hazard in more detail.
5.3.2 Damage Cases
State and EPA regional files were reviewed in an effort to document the performance of waste
management practices for gasifier ash and process wastewater at Dakota Gasification's active facility in Beulah,
North Dakota, and at two inactive coal gasification facilities: Ashland in South Point, Ohio; and Fairfield in
Fairfield, Iowa.7 The file reviews were combined with interviews with State and EPA regional regulatory staff.
Through these case studies, EPA found documented environmental damages associated with the gasifier ash
management units at the Dakota Gasification facility.
Dakota Gasification Company, Beulah, North Dakota
The plant site is located on a broad valley that is underlain by the Antelope Valley or Beulah Trench
aquifer. The Beulah Trench interconnects with the aquifer associated with the Knife River Valley, which
serves as a water supply source for the communities of Beulah and Hazen, located approximately nine miles
7 Facilities are considered inactive for purposes of this report if they are not currently engaged in primary mineral processing.
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5-14 Chapter 5: Coal Gasification
south and 14 miles southeast of the plant site, respectively. The mine used as the coal supply for the plant
is located immediately east of the facility site.8
As described earlier in this chapter, ash from the gasifier is quenched (with blowdown from the wet
scrubber system on the facility's incinerator) and sluiced into one of four ash sumps where the ash is settled
from the slurry. The liquid recovered during the ash dewatering is recycled back to the ash quench and
sluicing area or used as makeup water to the liquid waste incinerator. The dewatered ash is trucked to an on-
site landfill.
The landfill area designated as SU-101 is currently the active portion of the landfill that receives
gasifier ash. Large pits within the SU-101 area are utilized for the disposal of the gasifier ash and other waste
streams. According to the North Dakota State Department of Health and Consolidated Laboratories
(NDSDHCL), at least 90 percent of all waste disposed in SU-101 consists of gasifier ash. Excess liquids from
the gasifier ash disposed in area SU-101 flows with any additional run-off to the adjacent sumps and may be
later pumped to the evaporation pond. Analytical data from August 1989 show that the pH of water in the
sump ranges from 12.7 to 13.7, while the arsenic concentration ranges from 13.8 mg/L to 22.0 mg/L, and the
selenium concentration ranges from 1.1 mg/L to 2.2 mg/L.9'10'11
In December 1985, NDSDHCL expressed concerns to ANG (the former owner of the facility)
regarding the levels of water in the run-off pond [sump] within the ash storage area, because of high pH and
high arsenic content in the run-off water. The Department stated that the disposal of gas ash containing
excess liquids must be discontinued immediately.12
In July 1987, NDSDHCL Division of ^feste Management and Special Studies prepared a
memorandum that summarizes letters written and inspections conducted relating to ANG's gasifier ash
dewatering system and disposal area. This memorandum requested the issuance of a Notice of Violation to
ANG for improper waste handling procedures relating specifically to the dewatering of gasifier ash, the
unauthorized placement of associated liquids and sludges having potentially hazardous characteristics in the
gasifier ash disposal area, and the spillage of ash, liquids and sludges during transport from the dewatering area
to the ash disposal area. The memorandum discusses ANG's violations of the State's Solid Waste
Management rules, including the unauthorized placement of liquid and semi-liquid wastes in a landfill not
permitted for such wastes, the unauthorized improper construction and operation of the disposal site, the
inadequate protection of surface water in violation of permit conditions, and the spillage of liquids, sludges,
and ash during transport. As stated in the memorandum: "ANG's [practices have]... increased the potential
for groundwater degradation and [have] probably resulted in some surface water degradation."13
According to the NDSDHCL, Dakota Gasification discontinued the use of unlined ponds for the
disposal and storage of liquid bearing wastes in 1988. Ponds since mid-1988 have at least a clay liner. The
most recently completed pond has a composite liner. The state also noted that although the liquid bearing
wastes are still being disposed into a clay lined landfill, excessive run-off is directed into a pond with a
composite liner.14
According to monitoring reports submitted by DGC to NDSDHCL presenting quarterly data from
April 1988 to June 1989, monitoring wells around a portion of the landfill area indicated significant differences
8 Nonb Dakota State Department of Health and Consolidated Laboratories (NDSDHCL). 1989. Letter from S. Tillotson to C.
Greathouse, Re: Dakota DCC SU-101. December 21.
9 NDSDHCL. 1990. Personal Communication with S. Tillotson. January.
10 Dakota Gasification Company. 1989. Letter from D.R. Guminski, Environmental Manager, to M. Shock, NDSDH. November 17.
11 NDSDHCL, 1990. Letter from S. TilloUon to C. Greathouse, Re: DGC SU-101. February 20.
12 NDSDHCL, 1985. Letter from M. Schock to G. Weinreich, ANG, Re: SU-049. With Attachments. December 1Z
13 NDSHDCL. 1987. Interdepartmental Memorandum from S. Tillotson to B. Dellmore, through M. Schock, Re: ANG Notice of
Violation. July 20.
14 NDSDHCL. 1990. Letter from S. Tillotson to K. McCarthy, ICF, Re: Dakota Gasification Company SU-101. May.
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Chapter 5: Coal Gasification 5-15
in downgradient wells as compared to upgradient wells. From five to six total samples taken from upgradient
wells 15, 16, and 17, Electrical Conductivity (EC) averaged 4,790 /iinhos/cm; sulfates (SO4) averaged 1,248
mg/L; and total dissolved solids (TDS) averaged 3,638 mg/L. From eight total samples taken from
downgradient wells, 14, 18 and 24, EC averaged 11,870 /xmhos/cm; SO4 averaged 7,056 mg/L; and TDS
averaged 11,569 mg/L.
Monitoring well analytical data in a DGC report dated February 22, 1989, indicated that three
additional wells near the ash disposal area had exhibited "increased concentrations" of some constituents.
Analysis of samples from one of these wells revealed increased mean specific conductance (15,000 /imhos/cm),
as well as increased mean concentrations of sodium (3,000 mg/L), sulfates (11,000 mg/L), and TDS
(17,000 mg/L). Background, or upgradient data, were not provided. The other two wells contained similar
concentrations, and over a period of one year or less, historical data document the increases in these
constituent levels (Exhibit 5-5).15
5.3.3 Findings Concerning the Hazards of Coal Gasification Wastes
Based upon the detailed examination of the inherent characteristics of coal gasifier ash and process
wastewater, the management practices that are applied to these wastes, the environmental setting in which the
materials are managed, and the documented environmental damages that have been described above, EPA
concludes that these wastes pose a low risk to human health and the environment.
Intrinsic Hazard of the Wastes
Review of the available data on constituent concentrations in gasifier ash and its leachate indicates
that only arsenic and silver exceed one or more of the screening criteria by more than a factor of 10, though
maximum concentrations of these two constituents exceed the screening criteria by a wide margin (1,100 in
the case of arsenic and 370 in the case of silver). Based on one sample result, the concentration of uranium-
238 exceeds the radiation screening criterion by almost a factor of four, suggesting that uranium and its decay
products could pose an unacceptable radiation risk if the ash were used in an unrestricted manner. Combined
with the fact that the ash does not exhibit any of the four hazardous waste characteristics, these findings lead
EPA to conclude that the intrinsic hazard of this waste is low to moderate. These data also suggest that the
documented ground-water contamination described above in Section 5.3.2, was caused, at least in part, by
wastes other than gasifier ash that had been co-disposed in the ash landfill.
Exhibit 5-5
Increases in Concentrations of Selected Constituents
in Two Gasifier Ash Disposal Area Monitoring Wells (1987 -1988)
Well
W04018
W04020
Net Increase In Parameter Value Between
Sampling Periods
Ct
(««g/L)
3,910
2,114
*o*
(mo/lj
840
525
Na
(mg/i)
1,125
877
Spec. Cond.
(pmhM/cm)
11,290
5,200
TDS
(mg/L)
—
3.759
15 Dakota Gasification Company. 1989. Letter from A.C. Lukes to S. Tillotson, NDSDH, Re: Ground-water Monitoring Assessment
Plan-SU-049. February 22.
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5-16 Chapter 5: Coal Gasification
Review of the available data on process wastewater constituent concentrations indicates that 19
constituents exceed one or more of the screening criteria and that seven exceed the criteria by more than a
factor of 10. The available data also indicate that the waste does not exhibit any of the four hazardous waste
characteristics. As a result, EPA believes that the intrinsic hazard of this waste is moderate.
Potential and Documented Dangers
Evaluation of the potential for release, transport, and exposure through the ground-water, surface
water, and air pathways indicates that potential releases of contaminants in the process wastewater are limited
by engineered release controls, and that improper construction and waste handling at the ash landfill has
caused past releases to ground- and surface water. Nevertheless, the potential for current exposures to any
released contaminants is low because of the relatively large distance from waste management units to potential
exposure points.
Releases to ground water from the surge pond are unlikely because this unit is double-lined and has
two leachate collection systems. In contrast, the documented case of danger to human health and the
environment indicates that the design and operation of the ash landfill do not control the release of coal
gasifier ash or other contaminants to ground water. Any ground-water contamination arising from the ash
landfill at present, however, is unlikely to threaten human health or ground-water use given the relatively low
levels of contamination in ash leachate, the current lack of use of ground water in the area, and the relatively
large distance to existing downgradient residents where exposures could occur.
Releases from the process wastewater surge pond to surface water via ground-water discharge are
limited by the ground-water controls mentioned above, and overland flow of surge pond overflow is limited
by run-off controls. The damage case indicates that surface water degradation may have occurred due to ash
management practices, but it is unlikely that contamination from the ash would pose significant threats to the
Knife River or its tributaries given the large distance to the river and its perennial tributaries and the large
flow of the river. Residual contamination in a drainage ditch and nearby intermittent stream, however, may
adversely affect aquatic organisms living in these habitats.
Releases to air are limited by dust suppression at the landfill. In addition, any contaminants released
in windblown ash or volatilized from the surge pond would pose a small risk because of the large distance (>
1 km) to the nearest residence in a predominant wind direction.
Conclusions
Based on the low to moderate degree of intrinsic hazard of the wastes, the limited potential for
release, transport, and exposure via the ground-water, surface water, and air pathways, and the limited evidence
of documented cases of danger to human health or the environment from current waste management practices,
EPA concludes that the potential danger posed by coal gasifier ash and process wastewater from coal
gasification is limited. Accordingly, the Agency has investigated current applicable regulatory requirements
and alternative waste management and utilization, but has not examined in detail the costs and associated
impacts of additional regulatory requirements.
5.4 Existing Federal and State Waste Management Controls
5.4.1 Federal Regulation
EPA is unaware of any specific Federal management control or pollutant release requirements that
apply specifically to coal gasifier ash or process wastewater from coal gasification.
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Chapters: Coal Gasification 5-17
5.4.2 State Regulation
The single coal gasification facility addressed by this report is located in Beulah, North Dakota. The
State of North Dakota excludes mineral processing wastes from its hazardous waste regulations, but classifies
the coal gasification wastes generated at the Beulah facility as "special wastes" under the state's solid waste
regulations. Under this approach, North Dakota currently regulates the disposal of gasifier ash by requiring
that the landfill into which the ash is placed be permitted. Permit requirements include standards for liners,
closure, and post-closure care. Unlike the landfill requirements, North Dakota has not required that the
process wastewater pond at this facility be permitted. The state, however, did ensure that liners and other
engineering controls were used by the facility in constructing the pond. North Dakota is in the process of
amending its solid waste regulations, which as proposed would require the permitting of surface impoundments
used for coal gasification process wastewater storage and management. The extent and nature of any
additional technical criteria applied to these units or to gasifier ash landfills, however, cannot be predicted.
Finally, although North Dakota's air pollution control rules include provisions for control of paniculate matter
releases from industrial processes, the air permit for the Beulah facility does not directly address the facility's
waste management units.
5.5 Waste Management Alternatives and Potential Utilization
As noted above, the available data indicate that gasifier ash and process wastewater do not exhibit
any of the characteristics of hazardous waste. Consequently, the issue of how a gasification facility might
modify its operations or waste management practices or be stimulated to develop alternative uses for the ash
in response to prospective hazardous waste regulation is moot. Nevertheless, this section provides a brief
summary of current coal gas waste management practices and potential areas of utilization.
Coal Gasification Process Wastewater
The process wastewater has an average pH of 9.8 with approximately 0.2 percent solids. Instead of
being used as make-up water for the cooling system, the process wastewater could be treated and discharged,
although the practicality of this option is limited because the facility is located in a water short area. In
addition, the wastewater could be treated to remove contaminants prior to use in the cooling system. This
approach would be less efficient than current practices, however, because the efficiency with which
contaminants can be removed from the wastewater generally increases with increasing concentration, and use
of the wastewater in the cooling system increases the contaminant concentrations through evaporation.
Coal Gasifier Ash
Although none of the ash currently being generated is sold for commercial use, ash with sufficient
pozzolanic properties could be used in the manufacture of cement and concrete products. However, the levels
of uranium-238 and other contaminants make it uncertain whether utilization of the ash in this fashion would
be adequately protective of human health and the environment. In addition, utilization requires an available
market and it is not clear that a significant market exists near enough to the facility to be economical.
Alternative approaches to disposal would include installation of a synthetic liner and leachate
collection system in the on-site landfill and run-off pond.
5.6 Cost and Economic Impacts
Because the available data indicate that gasifier ash and process wastewater do not exhibit any of the
characteristics of hazardous waste, the issues of how waste management costs might change because of new
requirements associated with regulation as hazardous wastes under RCRA Subtitle C for these wastes and what
impacts such costs might impose upon affected facilities is moot. Consequently, no incremental costs or
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5-18 Chapter 5: Coal Gasification
associated economic impacts would result from a decision to remove the mining waste exclusion for these
wastes.
5.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) potential for and documented
danger to human health and the environment; (2) the need for and desirability of additional regulation; and
(3) the costs and impacts of potential Subtitle C regulation.
Coal Gasifier Ash
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of coal gasifier ash is low to moderate as compared to other mineral processing
wastes studied in this report. The ash does not exhibit any of the four characteristics of hazardous waste, and
data on constituent concentrations in solid samples and laboratory leachate of the ash indicate that only two
constituents are present in concentrations greater than 10 times the screening criteria used in this analysis.
The ash, however, may contain uranium-238 and its decay products in concentrations that could pose an
unacceptable radiation risk if the solids were allowed to be used in an unrestricted manner.
In addition to the relatively low to moderate intrinsic hazard of this waste, current management of
the ash at the coal gasification facility in Beulah, North Dakota (the only facility addressed by this report)
appears to limit the potential for the ash to threaten human health or the environment. Although there is
the potential for release of constituents to ground water at the North Dakota facility, as evidenced by
documented releases of contaminants to ground water underlying the ash landfill, the potential for significant
risks resulting from drinking water exposure is low because of the relatively large distance from waste
management units to potential exposure points. Similarly, threats to human health and the environment from
releases to surface water are limited by the large distance to the nearest downgradient perennial streams and
the relatively large flow of the Knife River. The release of contaminants to the atmosphere is limited by dust
suppression measures at the landfill, and in any case, would pose a small risk because of the large distance to
the nearest residence.
Environmental damages associated with the Dakota Gasification ash management facility have been
documented by the State of North Dakota, and reveal that drainage from an ash landfill was observed to have
pH values of 12.7 to 13.7, arsenic concentrations of 13.8 to 22.0 mg/L, and selenium concentrations of 1.1 to
2.2 mg/L. EPA believes, however, that these high levels are caused in large pan by wastes other than the ash
that were co-managed in the landfill, because leach test analyses of the ash by itself show significantly lower
concentrations. In addition, as discussed above, the potential for significant exposures to this contamination
appears low.
Likelihood That Existing Risks/Impacts Will Continue in the Absence of Subtitle C Regulation
The relatively low to moderate intrinsic hazard of the waste and the waste, management practices and
environmental conditions that currently limit the potential for significant threats to human health and the
environment are expected to continue in the future in the absence of more stringent federal regulation. The
character of the ash is unlikely to change in the future, and despite the fact that the analysis of potential
dangers is limited to the one active site at which the waste is currently managed, EPA believes that the
conclusion of low hazard can be extrapolated into the future unless coal gasifier ash is managed in locations
that are closer to potential exposure points. However, it is unlikely, for two reasons, that risks would occur
at other locations in the future. First, without the kind of subsidy provided for the construction of the existing
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Chapter 5: Coal Gasification 5-19
facility, it is unlikely that economic conditions would favor the construction and operation of new facilities
in the near future. Second, gasifier ash is not currently used or disposed off-site, though there is a slight
possibility that ash with certain properties could be used at alternate sites in the future for the manufacture
of cement and concrete products.
The potential for increased risks from gasifier ash management in the future is further restricted by
substantial State regulation of the ash landfill. North Dakota's regulatory program excludes gasifier ash
generated at the Beulah facility from hazardous waste regulation, addressing it instead as a "special waste"
under the State's solid waste rules. Under this approach, North Dakota currently regulates the disposal of
gasifier ash by requiring that the landfill into which the ash is placed be permitted. Permit requirements
include standards for liners and closure. The State is currently in the process of amending its solid waste
regulations, though the likely effects of these amendments on coal gasifier ash management and disposal are
not clear.
Costs and Impacts of Subtitle C Regulation
Because of the low risk potential of gasifier ash, the general absence of documented damages
associated with this material, and the fact that this waste does not exhibit any characteristics of hazardous
waste, EPA has not estimated the costs and associated impacts of regulating gasifier ash from coal gasification
under RCRA Subtitle C.
Coal Gasification Process Wastewater
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of coal gasification process wastewater is moderate compared to other mineral
processing wastes studied in this report. The process wastewater does not exhibit any of the four
characteristics of hazardous waste. Data on constituent concentrations in the wastewater, however, indicate
that seven constituents are present in concentrations that exceed the screening criteria used in this analysis
by at least a factor of 10.
Although the intrinsic hazard of this wastewater is moderate, current management of the wastewater
at the Dakota Gasification facility in North Dakota appears to limit the potential for this waste to threaten
human health or the environment. Releases from the surge pond to surface or ground waters are considered
unlikely because of the pond's double synthetic liner, leachate collection systems, and runoff controls. In
addition, any contaminants released by the volatilization, seepage, or run-off of the process wastewater would
pose little risk because of the large distance to potential exposure points.
The lack of documented cases of damage attributed to coal gasification process wastewater confirms
that the waste, as currently managed, appears not to cause significant health or environmental impacts.
Review of State and EPA Regional files and interviews of State and EPA Regional regulatory staff did not
produce any evidence of documented environmental damages attributable to management of process
wastewater at the active Dakota Gasification facility and two inactive coal gasification facilities.
Likelihood That Existing Risks/Impacts Will Continue in the Absence of Subtitle C Regulation
The relatively low hazard posed by current management of coal gasification process wastewater is
expected to continue in the future in the absence of Subtitle C regulation. The characteristics of this waste
are unlikely to change in the future, and despite the fact that the analysis of potential dangers is limited to
the Dakota Gasification facility, EPA believes that the conclusion of low hazard can be extrapolated into the
future unless coal gasification process wastewater is managed in locations that are closer to potential exposure
points or in ponds with less comprehensive release controls. However, it is unlikely that risks would occur
at other locations in the future because construction of new gasification facilities is not foreseen and it is
unlikely that the wastewater would be managed off-site.
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5-20 Chapter 5: Coal Gasification
The potential for increased risks from coal gasification process wastewater management in the future
is further restricted by substantial State regulation of "special waste" management units. North Dakota's
regulatory program excludes coal gasification process wastewater generated at the Beulah facility from
hazardous waste regulation, addressing it instead as a "special waste" under the State's solid waste rules. The
State has not required that the process wastewater ponds at this facility be permitted, though the State did
ensure that liners and other engineered controls were adopted in the construction of the surge pond. North
Dakota is currently in the process of amending its solid waste regulations, which would require the permitting
of process wastewater surge and cooling ponds, though the extent of permit requirements and their effect on
the management and disposal of the wastewater is not clear.
Costs and Impacts of Subtitle C Regulation
Because of the low risk potential of process wastewater from coal gasification and the absence of
documented damages associated with this material and the fact that this waste does not exhibit any
characteristics of hazardous waste, EPA has not estimated the costs and associated impacts of regulating
process wastewater from coal gasification under RCRA Subtitle C.
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Chapter 6
Primary Copper Processing
The domestic primary copper processing industry analyzed in this report consists of ten facilities that,
as of September 1989, were active and reportedly generating one or more of the following mineral processing
special wastes: slag (i.e., smelter, converter, and/or anode furnace slag), slag tailings, or calcium sulfate sludge
from wastewater treatment. These ten primary processing facilities1 conduct a variety of smelting and refining
operations, including electrolytic refining.2 The data included in this section are discussed in additional detail
in a technical background document in the supporting public docket for this report.
6.1 Industry Overview
The majority of the copper consumed in the U.S. is used in the electrical industry. It is used for a
wide range of wiring applications (from power transmission lines to printed circuit boards), in microwave and
electrical tubes, motors and generators, and many other specialized applications where its high electrical and
thermal conductivity can be employed. While copper has been replaced in some applications by aluminum
(e.g., for overhead power lines) and fiber optics (e.g., in telecommunications), its durability, strength, and
resistance to fatigue assure its continued use in the electrical industry. These latter three characteristics also
make copper and copper alloys a valued material in construction and containment (e.g., pipes and tanks), and
in other applications where endurance and resistance to corrosion are required.3
The ten facilities in this study consist of four primary smelting and fire-refining facilities; four primary
smelting, fire-refining, and electro-refining facilities; and two primary fire and electro-refining facilities, as
shown in Exhibit 6-1. These facilities are located in five states, with nine of the ten facilities located in the
Southwest. The dates of initial operation for these facilities range from 1912 to 1984; the average age is
approximately 33 years. Most of the facilities have undergone modernization; the most recent in 1989. The
total annual primary copper smelting production capacity is approximately 1.27 million metric tons per year
of anode copper; the primary copper refining capacity is about 1.33 million metric tons per year of refined
copper.
Primary production of copper in the U.S. has steadily increased throughout the late 1980s. Between
1986 and 1989, production from domestic and imported materials increased by 38 percent. Imports of refined
copper for consumption have decreased by 40 percent (from 502,000 metric tons to 300,000 metric tons) since
1986, while exports have increased 833 percent (from 12,000 metric tons to 100,000 metric tons). Total
apparent consumption has risen slightly from 2,136,000 metric tons in 1986 to 2,250,000 metric tons in 1989.4
Several companies have announced plans for improvements and expansions of existing facilities or opening
new facilities in the early 1990s that would further increase the supply of copper coming from the U.S.
ASARCO plans to expand its mining capacity and to employ a new flash smelting process at its El Paso, Texas
facility.5 Kennecott has announced plans to increase production at its Utah copper operation by 32,000
1 In addition to the 10 primary facilities, several secondary processing facilities are operating; the operations conducted at these
facilities, however, fall outside the definition of primary mineral processing and, thus, do not generate special mineral processing wastes.
2 At least seven additional facilities concentrate copper at stand-alone electrowinning operations. These are, however, considered
beneficiation operations, as long as they do not use as primary feedstock, materials that have undergone mineral processing operations,
e.g., smelting and refining, (see 54 FR 36592, September 1,1989). These facilities, their operations, and the wastes that they generate are
not within the scope of this report.
3 Bureau of Mines, 1985. Mineral Facts and Problems. 1985 Ed., p. 206-7.
4 Janice Jolly and Daniel Edelstein, U.S. Bureau of Mines, Mineral Commodity Summaries. 1990 Ed., p. 52.
5 Tim O'Neil, "ASARCO: Plant Expansions and Modernizations Continue Amidst Company Restructuring.1' Mining Engineering, June
1989, p. 430.
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6-2 Chapter 6: Primary Copper Processing
Exhibit 6-1
Primary Copper Processing Facilities
Owner
ASARCO
ASARCO
ASARCO
RTZ/Kennecott
Copper Range
Cyprus
Magma
Phelps Dodge
Phelps Dodge
Phelps Dodge
Location
AmariHo, TX
El Paso, TX
Hayden, AZ
Garfield, UT
White Pine, Ml
Claypool, AZ
San Manuel, AZ
El Paso, TX
Hurley, NM
Playas, NM
Presence of Operation Type
Smelter and
Converter
No
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Anode Furnace
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Electrolytic
Refinery
Yes
No
No
Yes
Yes
Yes
Yes
Yes
No
No
metric tons per day.6 Finally, Mitsubishi has announced its intention to build a smelter at Texas City, Texas
that would produce 150,000 metric tons of blister copper per year.7
The demand for copper is closely tied to the overall economy, and demand has remained relatively
fiat through the late 1980's. Future demand depends upon the health of the economy in the 1990s. Almost
40 percent of the 1988 U.S. consumption of copper went to the building and construction industries, while
about 23 percent was used by the electrical and electronic industries. Industrial machinery and equipment,
the power generation industry, and the transportation industry together consumed 38 percent of the copper
produced in 1988.8 Clearly, the development of new infrastructure in the U.S. and abroad would increase
the worldwide demand for copper, but consumption per unit of new gross product would be less than that in
the past because substitutes for copper are often used in a number of industries. For example, new telephone
infrastructure is being based upon fiber optic technology rather than copper to a significant degree.9
Continued re-opening of mothballed copper facilities, expansion of existing facilities, and development of new
mines could lead to copper supplies increasing faster than demand.10
As seen in Exhibit 6-2, primary copper production operations include, in general, smelting, converting,
fire refining in an anode furnace, and electrolytic refining. The products from each operation, respectively,
are copper matte, blister copper, copper anodes, and refined copper. The term "copper smelting" is sometimes
used to refer to the combined operations of smelting (in reverberatory, electric, or flash furnaces), converting,
and often, when co-located, fire refining. For purposes of this report, smelting will refer to the initial step,
in which the concentrate is first fused (i.e., heated to a point above the melting point of the mineral value).
6 "Kennecott Expanding Utah Copper," EAMJ. February 1990, p. 14.
7 Simon D. Strauss, "Copper 1989 Was a Good Year 121st Annual Survey and Outlook," EAMJ. March 1990, p. 19.
8 "Copper's Future is as dear as the Economy," EAMJ. January 1990, p. 15.
9 Ibid.
10 Ibid.
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Chapter 6: Primary Copper Processing 6-3
Exhibit 6-2
Primary Copper Processing
PROCESS
Processed
Stag
Concentrate
SPECIAL WASTE
MANAGEMENT
Ore
Aqueous
Wastes
Surface
Impoundment
Settling
Storage or
Disposal
Calcium Sulfate
Sludge
or Disposal
of Non—special
Wastes
Legend:
Production Operation
Special Waste
o
Waste Management Unit
Smelting involves the application of heat to a charge of copper ore concentrate, scrap, and flux, to
fuse the ore and allow the separation of copper from iron and other impurities. Several types of smelting
furnaces are in use in the U.S., as shown in Exhibit 6-3. In all operations the furnaces produce two separate
molten streams: copper-iron-sulfide matte and slag. The smelter slag, a special waste, is essentially a mixture
of flux material, iron, and other impurities; the slag is typically hot dumped (i.e., poured into a storage/disposal
pit or pile while still molten) and air cooled or cooled with water, or cooled with water (granulated) prior to
dumping. The slags from some smelting furnaces are higher in copper content than the original ores taken
from the mines. These slags, therefore, may be sent to a concentrator and the concentrate returned to the
smelter. The waste portion of this slag processing operation is the second special waste, slag tailings from
primary copper processing. Three facilities report reprocessing their slag, thereby generating slag tailings, a
special waste.
The copper matte from the smelter furnace is typically routed hot to the converter furnace; some
facilities have actually combined these operations. In either case, a high-silica flux and compressed air or
oxygen are introduced to the molten matte. Most of the remaining iron combines with the silica to form
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6-4 Chapter 6: Primary Copper Processing
Exhibit 6-3
Summary of Furnace Types
Facility
ASARCO, El Paso
ASARCO, Hayden
RTZ/Kennecott
Copper Range
Cyprus
Magma
Pheips Dodge/Hurley
Phelps Dodge/Playas
Furnace Type
Reverberatory (with pre-roaet}
Flash (Outokumpu)
Noranda Reactor (Continuous Process)
Reverberatory
Electric
Flash (Outokumpu)
INCO Flash
Electric and Flash (Outokumpu)
converter slag, a special waste.11 After removing the slag, additional air or oxygen is blown in to oxidize the
sulfur and convert the copper sulfide to blister copper that contains about 99 percent copper; the sulfur is
removed in the form of SO2 gas, which reports to an acid plant where it is converted to high grade sulfuric
acid. Depending on the efficiency of the acid plant, some amount of SO2 is emitted to the atmosphere.
Oxygen and other impurities in blister copper must be removed before the copper can be fabricated
or cast into anodes for electrolytic refining. Blister copper is fire refined in reverberatory or rotary furnaces
known as anode furnaces; all ten facilities operate anode furnaces. When co-located, the furnace may receive
the blister copper in molten form so remelting is unnecessary. Air is blown in to oxidize some impurities; flux
may be added to remove others. A slag is generated during this anode furnace operation. This slag is also
a component of the special waste.12 The final step in fire refining is the reduction of the copper and oxygen
removal using reformed natural gas of logs (poting) while it is still in the anode furnace, after which the
molten copper may be cast into anodes for further electrolytic refining or wire-rod forms.
Electrolytic refining, the final refining operation, does not directly generate a special waste and is not
described in detail for this report. Along with the operations described above, however, electro-refining does
produce various aqueous waste streams (e.g., process wastewater, bleed electrolyte) that must be treated and
discharged, reused, or disposed in some manner. Many of the facilities use a wastewater treatment operation
to treat these wastes. Two of the ten facilities, the Hayden, AZ and Garfield, UT facilities, use a treatment
process employing lime as an additive to neutralize the wastewaters and precipitate dissolved metals. The solid
residual from these treatment operations is a calcium sulfate sludge, which is the third special waste generated
by the primary copper sector.
6.2 Waste Characteristics, Generation, and Current Management Practices
The three special mineral processing wastes generated by copper processing operations, slag, slag
tailings, and calcium sulfate wastewater treatment sludge, are discussed separately below.
11 Most if not all converter slag is recycled directly back to the smelter. When this occurs, this recycled material is not a solid waste
(see 40 CFR Part 261).
12 Most if not all anode furnace slag is recycled directly back to the converting furnace. When this occurs, this recycled material is
not a solid waste (see 40 CFR Part 261).
-------
Chapter 6: Primary Copper Processing 6-5
6.2.1 Slag from Primary Copper Processing
Slag from the smelting, converting, and anode furnaces is generated at eight of the ten facilities; the
other two facilities (in Amarillo and El Paso) do not have smelting operations and produce only small
quantities of anode furnace slag. Waste characteristic and generation rate data typically have not been
reported for converter and anode furnace slag, as the slags are directly recycled. Because of the difference in
generation rates and management of smelter slag versus converter and anode furnace slag (i.e., nearly all
converter and anode furnace slag is recycled), smelter furnace slag is discussed separately from converter and
anode slags.
Smelter Slag
Smelter slag is molten when tapped from the reactors and solidifies into a glassy, rock-hard mass upon
cooling. When crushed, pieces of the copper slag may range in size from gravel to boulder, or even larger.
The SWMPF Surveys describe the slag as a solid; typically gravel or cobble sized; and composed primarily of
iron silicates, calcium oxide, and alumina (aluminum oxide), with small amounts of copper, lead, zinc, and
other metals. The specific gravity of the slag is usually between 3.0 and 3.5.13
In 1988, the eight active smelters generated approximately 2.5 million metric tons of smelter slag.
On an individual facility basis, the quantity generated at the six smelters that provided non-confidential data
ranged from about 165,000 to nearly 500,000 metric tons. The smelter slag to copper anode production ratio
is approximately 2.2 (i.e., 2.2 metric tons of smelter slag are generated for every ton of copper anode
produced).
At all eight copper smelters, smelter slag is initially deposited on waste piles. In five cases, the waste
piles are for temporary storage. At three of these five facilities, the slag is subsequently processed in a
concentrator and the resulting concentrate is returned to the smelter. At another facility, the slag is moved
to a pile at the edge of a tailings pond for disposal, and at the fifth, the slag is, in part, sold. At the three
remaining facilities, the slag is disposed of in the waste piles and remains there indefinitely.
Three smelters process all their smelter slag either in their ore concentrator (San Manuel and White
Pine) or, in the case of the Utah facility, in a stand-alone slag concentrator. The process streams resulting
from this operation are slag tailings, discussed below as a separate special waste, and a copper concentrate
which is sent to the smelter as feedstock. Information on the stockpiles of smelter slag at two of these
facilities was not reported. At the White Pine facility, the slag is dumped in a slag pile covering 24 hectares
(60 acres) and 3 meters (10 feet) in height, from which the slag is periodically removed and sent to the
concentrator. This slag dump has accumulated as of 1988,136 million metric tons of slag; having been used
as a disposal unit for some years. In 1988, however, more slag was removed from the dump for slag processing
(212,000 metric tons) than was generated from the smelter (165,000 metric tons).
The temporary slag pile at the ASARCO/E1 Paso facility which, in 1988 sold its slag, is much smaller
in comparison to the disposal piles, with a basal area of 0.9 hectares (2.1 acres) and 6 meters (20 feet) high;
450,000 metric tons of slag had accumulated as of 1988.
Four facilities (Hayden, AZ, Claypool, AZ, Playas, NM and Hurley, NM) dispose of all or part of the
slag in on-site slag piles or slag dumps. The Claypool facility disposes of its slag in a pile at the edge of a
tailings pond. As of 1988, the basal area of these slag piles ranged from 7 to 26 hectares (17 to 64 acres), and
the height from 6 to 45 meters (20 to 150 feet.) The amount of slag accumulated in any one of these slag piles
ranges from 2.7 to 20.9 million metric tons.
Using available data on the composition of copper smelter slag, EPA evaluated whether the slag
exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and extraction
13 Collins, RJ. and R.H. Miller, Availability of Mining Wastes and Their Potential for Use as Highway Material - Volume 1:
Classification and Technical and Environmental Analysis. FHWA-RD-76-106, prepared for Federal Highway Administration, May 1976,
p. 113.
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6-6 Chapter 6: Primary Copper Processing
procedure (EP) toxicity. Based on available information and professional judgment, EPA does not believe the
slag is corrosive, reactive, or ignitable, but some slag may exhibit the characteristic of EP toxicity. EP leach
test concentrations of all eight inorganic constituents with EP toxicity regulatory levels are available for copper
smelter slag from seven of the ten facilities of interest. Of these constituents, cadmium and lead
concentrations, in one sample from just one facility (Phelps Dodge at Playas, NM), were found to exceed the
EP regulatory levels. Cadmium was present at concentrations in excess of 8.5 times the regulatory level, in
one of 70 samples. Likewise, lead concentrations exceeded the EP regulatory level in one of 68 samples, by
a factor of roughly three. Because the slag samples that failed the EP toxicity test were not analyzed using
the SPLP leach test, it is not clear if cadmium and lead concentrations would have exceeded the EP toxicity
levels if the SPLP test had been used.
Converter and Anode Furnace Slag
Approximately 380,000 metric tons of converter and anode slag are generated annually, ranging from
nearly 29,000 to just over 244,000 metric tons for the six non-confidential facilities with smelting operations;
the one non-confidential electrolytic refinery generated only 1,200 metric tons of anode furnace slag.
The primary management practice for both the converter and anode furnace slag is recycling. The
eight facilities that have smelters and, therefore, converter operations, all recycle their converter slag back to
the smelter furnace and their anode furnace slag back to their converter. ASARCO/Amarillo and Phelps
Dodge/El Paso each operate a stand-alone refinery with an anode furnace; both ship their anode furnace slag
back to one of their two company-owned smelters for resmelting. Temporary waste piles are used to store the
slag before it is shipped off-site.
6.2.2 Slag Tailings from Primary Copper Processing
Slag tailings from primary copper processing is a solid material, typically composed of particles smaller
than sand, that is settled from a slurry. Only three facilities, those in Michigan, Utah, and San Manuel, AZ,
presently send their smelter slags to a concentrator and thereby generate slag tailings. At the Michigan and
San Manuel, AZ facilities, the same concentrator is used for both ore and slag, so the slag tailings and ore
tailings are co-generated. The Utah facility has separate concentrators for the ore and slag, but the slag
tailings and ore tailings are mixed prior to disposal. The primary constituents in slag tailings reportedly are
silicon, iron, magnesium, sodium; smaller amounts of copper, lead, and zinc; and other trace elements.
Non-confidential waste generation rate data were provided to EPA by all three facilities generating
slag tailings. The aggregate annual industry-wide generation of slag tailings by the three plants was
approximately 1.5 million metric tons in 1988, yielding a facility average of nearly 504,000 metric tons per year.
Individual facility generation rates ranged from 206,000 to nearly 969,000 metric tons. The average waste-to-
product tonnage ratio (i.e., slag tailings to copper anode) for the three facilities was 1.4 in 1988.
Slag tailings are co-managed in on-site tailings ponds with tailings from ore beneficiation at all three
facilities. One facility, located in Michigan, has five tailings ponds on-site, while the other two facilities (in
Utah and Arizona) each have a single tailings pond. These ponds cover anywhere from 142 to 2,270 hectares
(352 to 5,600 acres) each. Industry-wide, these ponds cover a total area of 4,400 hectares, yielding a facility-
specific average of approximately 600 hectares. On average, the ponds are roughly 46 meters (150 feet) deep
(depth may range from 16 to 61 meters).
The combined amount of slag tailings accumulated at all seven ponds, as of 1988, is approximately
12.6 million metric tons. The average quantity of slag tailings accumulated in each pond is roughly 1.8 million
metric tons, although it could range from 241,000 to 3.4 million metric tons. At all three facilities, slag tailings
constitute a relatively minor portion of the total tailings (slag plus ore/mill tailings) held in each of the tailings
ponds. Slag tailings at the Michigan plant range from 0.2 to 3.5 percent of the total tailings in the five ponds.
At the other two facilities, slag tailings are 0.3 and 2.6 percent of the total tailings managed in the ponds.
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Chapter 6: Primary Copper Processing 6-7
Data available to EPA from site sampling visits and responses to a RCRA §3007 request, as well as
professional judgment, indicate that slag tailings do not exhibit any of the characteristics of hazardous waste
(i.e., ignitability, reactivity, corrosivity, or EP toxicity) at any of the facilities that generate the waste. These
data identify the concentrations of all eight inorganic EP constituents in slag tailings samples from two of the
three facilities (Garfield and San Manuel) that generate this waste. Using the EP leach test, all eight
constituents were measured in concentrations that were at least two orders of magnitude below the EP-toxicity
regulatory levels - that is, below primary drinking water standards.
6.2.3 Calcium Sulfate Wastewater Treatment Plant Sludge
From Primary Copper Processing
Calcium sulfate sludge is generated only by the facilities in Hayden, AZ, and Garfield, Utah from lime
treatment of wastewaters (e.g., acid plant blowdown). At the Utah facility, the sludge reportedly consists
primarily of calcium sulfate (70 percent), with between 0.1 and 0.5 percent copper, zinc, and lead. Additional
metals are present in trace amounts.14 The total annual generation of calcium sulfate sludge is estimated
to be approximately 140,000 metric tons per year and the average waste-to-product (smelter output) ratio is
0.42.15
The waste management practice used at both facilities is accumulation of the sludge solids in an on-
site impoundment. At the Utah facility, two on-site surface impoundments are used for sludge storage. Both
impoundments have a surface area of about 2.2 hectares (5.5 acres); one impoundment is 2.3 meters (7 feet)
deep and the other is 3 meters deep. One impoundment is used to accumulate sludge, while sludge previously
accumulated in the second ("inactive") impoundment is allowed to dry prior to dredging. The air-dried sludge
in the inactive impoundment is dredged and stabilized, and then disposed in a landfill that is located in a
designated area within the on-site tailings impoundment.
The Hayden, AZ facility also accumulates its calcium sulfate slurry in an on-site surface impoundment.
In 1988, approximately three percent of the sludge was dredged from the impoundment and recycled to the
flash furnace; the remainder was left to accumulate in the impoundment, which has an area of 3.35 hectares
(8 acres) and is 3.2 meters (10 feet) deep. The impoundment has an asphalt/rubber liner and run-on/run-off
controls; no leachate or wind dispersal controls are used.
Using available data on the composition of calcium sulfate wastewater treatment plant sludge, EPA
evaluated whether the waste exhibits any of the four hazardous waste characteristics: corrosivity, reactivity,
ignitability, and extraction procedure (EP) toxicity. Based on available information and professional judgment,
EPA does not believe that this waste is corrosive, reactive, or ignitable, but it does exhibit the characteristic
of EP toxicity. EP leach test concentrations of all eight inorganic constituents with EP toxicity regulatory
levels are available for one of the two facilities of interest (Garfield). Of these constituents, arsenic, cadmium,
and selenium concentrations were found to exceed their respective regulatory levels. Concentrations of arsenic
and selenium exceeded EP-toxicity regulatory levels in all of the seven samples analyzed, by factors as high as
140 and 14, respectively. Cadmium concentrations exceeded the EP-toxicity threshold in six of the seven
samples, by as much as four times the regulatory level. On the other hand, SPLP leach test concentrations
of metals with EP-toxicity limits were below the EP-toxicity regulatory levels for all of the samples analyzed.
14 According to the EPA waste sampling and analysis data, the sludge from primary copper processing contains copper (0.154%), lead
(0.144%), arsenic (0.117%), iron (0.0351%), zinc (0.0232%), aluminum (0.0157%), and smaller amounts of antimony, banum, beryllium,
cadmium, cobalt, mercury, manganese, molybdenum, nickel, selenium, silver, thallium, and vanadium.
u One of the two respondents to EPA's 1988 survey indicated that the quantity of calcium sulfate sludge generated was confidential.
As a result, the estimated average quantity presented here is based on alternative data sources as discussed in the technical background
document.
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6-8 Chapter 6: Primary Copper Processing
6.3 Potential and Documented Danger to Human Health and the Environment
In this section, EPA discusses two of the study factors required by Section 8002(p) of RCRA for
wastes generated in the copper processing sector: (1) potential risk to human health and the environment
associated with the management of copper slag, copper slag tailings, and calcium sulfate sludge generated at
copper processing plants; and (2) documented cases in which danger to human health and/or the environment
has been proven. Overall conclusions about the hazards associated with each of the three wastes are based
on the Agency's evaluation of these two factors.
6.3.1 Risks Associated With Copper Slag
Any potential danger to human health and the environment from copper slag is a function primarily
of the composition of the slag, the management practices that are used, and the environmental settings of the
facilities where the slag is generated and managed. These factors are discussed separately below, followed by
EPA's risk modeling results for this waste.
Constituents of Concern
EPA identified chemical constituents in copper slag that may present a hazard by collecting data on
the composition of slag, and evaluating the intrinsic hazard of chemical constituents present in the slag.
Data on Copper Slag Composition
EPAs characterization of copper slag and its leachate is based on data from three sources: (1) a 1989
sampling and analysis effort by EPAs Office of Solid \vaste (OSW); (2) industry responses to a RCRA §3007
request in 1989; and (3) sampling and analysis conducted by EPAs Office of Research and Development
(ORD) in 1984. These data provide information on the concentrations of 21 metals and a number of
inorganic constituents (i.e., phosphorus, fluoride, sulfate, and nitrate) in total and/or leach test analyses, and
represent samples from all 10 facilities that generate copper slag.
Concentrations in total (solid) samples of the copper slag are consistent for most constituents across
all data sources and facilities. Arsenic and nickel concentrations, however, varied over three orders of
magnitude across the facilities.
Concentrations of constituents from leach test analyses of the copper slag generally are consistent
across the data sources, types of leach tests (i.e., EP, SPLP, and TCLP), and facilities. In the EP analyses,
however, chromium, zinc, and lead concentrations varied over approximately three orders of magnitude across
the facilities.
Process for Identifying Constituents of Concern
As discussed in detail in Section 2.2.2, the Agency evaluated the data summarized above to determine
if copper slag or slag leachate contain any chemical constituents that could pose an intrinsic hazard, and to
narrow the focus of the risk assessment. The Agency performed this evaluation by first comparing the
constituent concentrations to screening criteria and then by evaluating the environmental persistence and
mobility of constituents present in concentrations above the criteria. These screening criteria were developed
using assumed scenarios that are likely to overestimate the extent to which the slag constituents are released
to the environment and migrate to possible exposure points. As a result, this process identifies and eliminates
from further consideration those constituents that clearly do not pose a risk.
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Chapter 6: Primary Copper Processing 6-9
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic ecosystems, and water resources (see Exhibit 2-3). Given the conservative (i.e., protective)
nature of these screening criteria, contaminant concentrations in excess of the criteria should not, in isolation,
be interpreted as proof of hazard. Instead, exceedances of the criteria indicate the need to evaluate the
potential hazards of the waste in greater detail.
Identified Constituents of Concern
Exhibits 6-4 and 6-5 present the results of the comparisons for copper slag (total) analyses and leach
test analyses, respectively, to the risk screening criteria. These exhibits list all constituents for which sample
concentrations exceed a screening criterion.
Of the 24 constituents analyzed in copper slag solids, arsenic, copper, lead, chromium, antimony,
silver, and nickel are present at concentrations exceeding the screening criteria (see Exhibit 6-4). Among these
constituents, arsenic, copper, and lead appear to pose the greatest potential threat because they were detected
in most (73 to 98 percent) of the samples analyzed, their concentrations in most (61 to 73 percent) analyses
exceed screening criteria, and their concentrations in samples from at least 5 of the 9 facilities exceed the
screening criteria. In addition, only arsenic, copper, and lead exceeded the screening criteria by more than a
factor of ten. All of these constituents are persistent in the environment (i.e., they do not degrade).
Exhibit 6-4
Potential Constituents of Concern in Copper Slag Solids^
Potential
Constituent*
of Concern
Arsenic
Copper
lead
Chromium
Antimony
Silver
Nickel
No. of Tinwft
Constituent
Detected/No, of
Analyaea
for Constituent
31/42
44/45
41/43
6/15
26/43
37/50
2t/ar ;
Human Health
Screening Criteria*'
ingestion*
Inhalation*
Ingestion
Inflection
Inhalation*
Ingection
Ingestion
inhalation*
No. of Analyses
Exceeding Criteria/
No. of Analyse* for
Constituent
31/42
26/42
28/45
31/43
3/15
9/43
25/50
2/27
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
6/9
5/9
5/9
6/9
3/8
2/9
2/9
t/9
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that
exceeds a relevant screening criterion. The conservative screening criteria used in this analysis are listed in
Exhibit 2-3. Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '"' are based on a 1x10'5 lifetime
cancer risk; others are based on noncancer effects.
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6-10 Chapter 6: Primary Copper Processing
Exhibit 6-5
Potential Constituents of Concern in Copper Slag Leachate(a)
Potential
Constituent*
of Concern
teed
Copper
Arsenic
Molybdenum'0'
Cadmium
Mercury
Iron
Barium
Chromium
Manganese
Zinc
No. of Time*
Constituent
Detected/No, of
Analyses
for Constituent
46/69
14/14
24/70
1/2
46/71
7/69
12/14
28/70
20/71
5/14
14/14
Screening Criteria04
Human Hearth
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Heafth*
Resource Damage
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
Resource Damage
Human Health
Resource Damage
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
15/69
37/69
12/69
2/14
2/14
13/14
24/70
2/70
1/2
6/71
8/71
7/71
3/69
2/14
1 /70
1 /70
1/71
1/71
1 /14
1/t4
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
6/10
7/10
6/10
2/8
2/8
8/8
7/10
1 /10
1 12
5/10
5/10
5/10
2/9
2/8
1 /10
1 /10
1 /10
1/1O
1/8
1 /9
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that
exceeds a relevant screening criterion. The conservative screening criteria used in this analysis are listed in
Exhibit 2-3. Constituents that were not detected in a given sample were assumed not to be present in the sample.
Unless otherwise noted, the constituent concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer risk or noneancer health effects. 'Human health' screening
criteria noted with an '*' are based on a 1x10"6 lifetime cancer risk; others are based on noneancer effects.
(c) Data for this constituent are from SPLP leach test results.
These exceedances indicate the potential for the following types of impacts under the following
conditions:
• Arsenic, copper, lead, and to a lesser extent, antimony and silver concentrations exceed
the ingestion criteria. This indicates that, if the slag (or soil contaminated with the slag)
is incidentally ingested on a routine basis then constituents may cause adverse health
effects. The concentration of arsenic in the slag would pose a lifetime cancer risk of
greater than IxlO'5 if incidentally ingested.
• Arsenic, chromium, and nickel concentrations exceed the health-based screening criteria
for inhalation. This indicates that these constituents could pose a cancer risk greater
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Chapter 6: Primary Copper Processing 6-11
than IxlO"5 if slag dust were blown into the air and inhaled in a concentration that
equals the National Ambient Air Quality Standard for particulate matter.
Based on a comparison of leach test concentrations of the 24 constituents to the surface and ground-
water pathway screening criteria (see Exhibit 6-5), 11 contaminants were detected in concentrations above the
criteria. Lead, copper, arsenic, molybdenum, and cadmium are present in concentrations that exceed at least
one screening criterion in samples from at least 50 percent of all facilities at which they were analyzed. The
other six constituents are present in concentrations that exceed the screening criteria in samples from no more
than two of eight facilities. Maximum lead, copper, and arsenic concentrations exceed the screening criteria
by more than a factor of 100, and maximum concentrations of molybdenum, cadmium, and mercury exceed
the criteria by more than a factor of 10. The other constituents exceed the criteria by less than a factor of 10.
As discussed in Section 6.2.1, the only constituents that were measured in concentrations that exceed the EP
toxicity regulatory levels were cadmium (in 1 of 70 samples) and lead (in 1 of 68 samples).
• Concentrations of lead, copper, arsenic, cadmium, and barium in copper slag leachate
exceed health risk (drinking water) screening criteria. This indicates that, if slag
leachate were released and diluted by only a factor of 10 during migration to a drinking
water exposure point, long-term ingestion could cause adverse health effects due to the
presence of these constituents. The concentration of arsenic in diluted slag leachate
could pose a cancer risk of greater than IxlO'5'
• Lead, copper, cadmium, mercury, chromium, and zinc in the slag leachate may present
a threat to aquatic organisms if it migrates (with a 100-fold dilution) to surface waters.
• Lead, copper, arsenic, molybdenum, cadmium, iron, barium, chromium, and manganese
in the slag leachate, if released and diluted by a factor of 10 or less, could restrict the
potential future uses of affected ground- and surface water resources.
These exceedances, by themselves, do not indicate that the slag poses a significant risk, but rather
indicate that the slag may present a hazard under a very conservative, hypothetical set of release, transport,
and exposure conditions. To determine the potential for the slag to cause significant impacts, EPA proceeded
to the next step of the risk assessment to analyze the actual conditions that exist at the facilities that generate
and manage the slag.
Release, Transport, and Exposure Potential
This analysis considers the baseline hazards of copper slag as it was generated and managed at the
10 plants of concern in 1988. For this analysis, the Agency did not assess the hazards associated with
variations in waste management practices or potentially exposed populations in the future because of a lack
of information adequate to predict future conditions. In addition, the following analysis does not consider the
risks of off-site disposal or use of the slag because the slag is disposed of only on-site. Although one facility
does sell its slag for off-site use and there is a potential for wider use of the slag in the future, insufficient
information about the conditions of off-site use is available to support a detailed assessment of risks.
Alternative slag management practices are discussed, however, in Section 6.5.
Ground-Wafer fte/eate, Transport, and Exposure Potential
EPA and industry test data discussed above indicate that several constituents are capable of leaching
from copper slag in concentrations that exceed the screening criteria. However, considering the existing slag
management practices and neutral pH of the leachate, the only slag contaminants that are expected to be
mobile in ground water if released are arsenic, molybdenum, cadmium, and to a lesser extent, barium and
chromium. Exhibit 6-6 summarizes the key factors at each copper facility that affect the potential for these
constituents to be released into ground water and cause impacts through that pathway.
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6-12 Chapter 6: Primary Copper Processing
Exhibit 6-6
Summary of Release, Transport, and Exposure Potential for Copper Slag
Facility
Release, Transport, and Exposure Potential for Copper Slag
Proximity to
Sensitive Environments
AMARILLO
Ground water: Although moderate recharge (10 cm/year) and
permeable subsurface (80 percent sand), useable aquifer very deep
(73m below facility) and thus somewhat protected.
Surface water: No permanent water body within 1.6 km; a nearby
playa lake could be contaminated by shallow ground-water dis-
charge, but water is present only intermittently; when present, water
may be used for livestock watering.
Air: Small number of wet days (66 days/year) and high wind
speeds (6.6 m/s) could lead to airborne dust and inhalation
exposures at closest residence 760 meters from the facility; sparse
population (5 people) within 1.6 km.
Not located in or near any
sensitive environments
ASARCO/EL PASO
Ground water: Temporary slag management area has no en-
gineered ground-water controls and ground water is shallow (3-6
meters), but releases are limited by low precipitation (20 cm/year)
and very low net recharge (0.5 cm/year); no drinking water wells
within 1.6 km of the facility.
Surface water: Overland releases to the Rio Grande River have
been documented (damage case); high potential for episodic
overland releases to nearby river (76 meters) because of steep
topographic slope (6-12%) and the facility is located in a 100-year
floodplain; river has large flow (520 mgd) that yields significant
dilution; drinking water intake 4 km downstream (500,000 people
served).
Air: Releases not controlled by dust suppression; small number of
wet days (41 days/year) that may suppress dust and wind speeds
up to 5.1 m/s could lead to airborne dust and inhalation exposures
at closest residence 90 meters from the facility; population within
1.6 km is 500.
Located in a 100-year
floodplain
HAYDEN
Ground water: Waste pile is not lined, annual precipitation is
moderate (50 cm/year) and subsurface is slightly permeable; very
low net recharge, i.e., 1.3 cm/year, creates low potential for releases
to shallow ground water located roughly 6 m below the land
surface; ground water does not appear to be used for any purpose.
Surface water: Routine overland releases to nearby Qila River
(located 80 meters from the facility) limited by stormwater
runon/runoff controls and the gentle (0-2%) topographic slope in the
area; low potential for releases to surface water via seepage to
ground water; no consumptive uses of the river within 24 km;
moderate flow of the river (170 mgd) allows moderate dilution, and
therefore, possible ecological risks.
Air: Releases not controlled by dust suppression; small number of
wet days (47 days/year), large exposed area of the pile, and wind
speeds up to 4.8 m/s could lead to airborne dust and inhalation
exposures at closest residence 90 meters from the facility; popula-
tion within 1.6 km is 2,200.
Not located in or near any
sensitive environments
No information is available on the slag management units at these sites. The information presented here is based
only on the environmental setting of the facility.
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Chapter 6: Primary Copper Processing 6*13
Exhibit 6-6 (continued)
Summary of Release, Transport, and Exposure Potential for Copper Slag
Facility
Release, Transport, and Exposure Potential for Copper Slag
Proximity to
Sensitive Environments
WHITE PINE
Ground water: High potential for releases to ground water due to
absence of engineered controls, moderately shallow depth to
aquifer (6-12 meters), high precipitation (73 cm/year), and relatively
high net recharge (18 cm/year); no drinking water wells within 1.6
km of the facility.
Surface water: Large annual precipitation and moderate topo-
graphic slope (up to 6%) together create potential for surface
erosion and overland runoff to a stream located 120 m from facility;
however, slag pile equipped with stormwater run-on/run-off controls
surface water monitoring has indicated exceedances of drinking
water and ambient water quality standards; episodic overland
releases due to sudden snow-melt (maximum snow accumulation is
94 cm/storm) and releases to surface water via seepage to ground
water could occur; stream has low dilution capacity (42 mgd);
potential drinking water exposures could occur from a water supply
intake 5 km downstream.
Air: Dust suppression is not practiced but moderate number of wet
days (116 days/year) could control airborne dust; wind speeds up
to 4.7 m/s have the potential for producing airborne dust that could
lead to potential airborne exposures at closest resident 730 meters
from the facility; population within 1.6 km is 1,200.
Located in a Fault Zone
and close to a National
Forest
GARFIELO
Ground water: Releases to useable ground water limited by low
precipitation (40 cm/year) and net recharge (0.7 cm/year) and large
depth to the aquifer (90 meters) that is overlain with clay, however,
monitoring shows ground water contamination has occurred;
contamination has not been attributed to copper slag; no drinking
water wells within 1.6 km.
Surface water: Episodic overland releases to the Great Salt Lake
(300 m from facility) could occur due to a flood-event or sudden
snow-melt (maximum snow accumulation is 102 cm); routine
overland releases and releases via seepage to ground water are of
lesser concern; low potential for exposure because the lake is not
used for drinking water.
Air: Releases not controlled by dust suppression; small number of
wet days (89 days/year) and wind speeds up to 4.9 m/s could lead
to airborne dust; significant potential for inhalation exposure
because population within 1.6 km is 10,000.
Located in a 100-year
floodplain and in a wet-
land
No information is available on the slag management units at these sites. The information presented here is based
only on the environmental setting of the facility.
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6-14 Chapter 6: Primary Copper Processing
Exhibit 6-6 (continued)
Summary of Release, Transport, and Exposure Potential for Copper Slag
Facility
Release, Transport, and Exposure Potential for Copper Slag
Proximity to
Sensitive Environments
SAN MANUEL*
Ground water: No information is available on the ground-water
controls at the temporary cooling pits for the slag that is recycled;
releases to uppermost useable aquifer are significantly limited by
large depth to the useabie aquifer (140 meters), moderate precipita-
tion and zero net recharge, and presence of an intervening layer of
impervious lake-bed deposits; closest drinking water well is located
150m from the facility.
Not located in, or near,
any sensitive environ-
ments
Surface water: Some potential for surface erosion because
moderate precipitation (50 cm/year), moderate topographic slope
(up to 6%) of the area, and moderate distance to nearby San Pedro
River (790 meters); very low dilution capacity (0.08 mgd) of the
stream could lead to ecological risks; no public water supply intake
within 24 km of the facility, but there is an intake for livestock
watering 1.2 km downstream.
Air: No information is available on dust suppression controls at the
slag cooling pits; airborne releases could be possible due to small
number of wet days (47 days/year) and average wind speeds up to
4.8 m/s; potential inhalation exposures could occur at closest
residence 330 meters from the facility; population within 1.6 km is
5,000.
PHELPS DODGE/
EL PASO
Ground water: Low potential for releases to ground water because
of low precipitation (20 cm/year), very low net recharge (0.5
cm/year), large depth to aquifer (76 m), and presence of an asphalt
liner beneath the temporary slag pile; no drinking water wells within
1.6 km downgradient of the facility.
Surface water: Overland releases are limited by stormwater
runon/runoff controls and low precipitation; given low potential for
ground-water contamination, very unlikely that contaminants could
migrate via ground water into Qila River located 550 m away;
contaminants pose low risks to aquatic receptors because the river
has a large dilution capacity (515 mgd); no consumptive uses of
the river within 24 km.
Air. Releases not controlled by dust suppression; small number of
wet days (41 days/year) and average wind speeds up to 5.1 m/s
could lead to airborne dust and inhalation exposures at closest
residence 30 meters from the facility; significant exposures could
occur because population within 1.6 km is 40,000.
Located in a Fault Zone
HURLEY
Ground water: Ground water monitoring has indicated con-
tamination, but the contamination has not been attributed to copper
slag; although no engineered ground-water controls and permeable
subsurface, the low net recharge (5 cm/year) and large depth to
ground water (30 m) help to limit releases from copper slag;
potential exposures could occur at drinking water well < 100 meters
downgradient of the facility boundary.
Surface water: There are no surface water bodies within 24 km of
the facility.
Ajr: Releases not limited by dust suppression controls; small
number of wet days (50 days/year) and average wind speeds up to
4.3 m/s could lead to airborne dust and inhalation exposures at
closest residence 6 meters from the facility; population within 1.6
km is 5,500.
Located in a 100-year
floodplain, Fault and
Karat Zones
No information is available on the slag management units at these sites. The information presented here is based
only on the environmental setting of the facility.
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Chapter 6: Primary Copper Processing 6-15
Exhibit 6-6 (continued)
Summary of Release, Transport, and Exposure Potential for Copper Slag
Facility
Release, Transport, and Exposure Potential for Copper Slag
Proximity to
Sensitive Environments
PLAYAS
Ground water: Potential for release to shallow aquifer (4 m) is
limited by low precipitation (26 cm/year) and zero net recharge;
potential for exposure is minimal because closest drinking water
well is more than 5 km downgradient.
Surface water: Low potential for surface erosion because of low
precipitation and gentle topographic slope of the area; seepage of
contaminants to ground water that may discharge into the nearby
(480 m) Playas Lake is also limited; lake water is not used for
human consumption but is used for livestock watering.
Air: Releases not limited by dust suppression controls; small
number of wet days (40 days/year) and average wind speeds up to
5.3 m/s could lead to airborne dust; however, potential for in-
halation exposures is relatively low because the closest residence is
approximately 3.7 km from the facility, and there is no population
within 1.6 km.
Located in a Fault Zone,
and within 9 miles of an
endangered species hab-
itat
CLAYPOOL
Ground water: Releases are not limited by any engineered
ground-water controls; standing liquid over some part of the slag in
the tailings pond provides a leaching medium; contaminants could
leach into the permeable subsurface (high percentage of sand);
aquifer is very deep (91 to 116 m); potential drinking water expo-
sures could occur at municipal well 12 km downgradient (approxi-
mately 9500 people rely on this well).
Surface water: The closest surface water (Salt River) is 24 km
away.
Air: Release not limited by dust suppression controls; small
number of wet days (43 days/year) that could suppress dust and
average wind speeds up to 3.4 m/s could lead to airborne dust and
inhalation exposure at closest residence 60 meters from the facility;
population wtthin 1.6 km is 1,000.
Located in a Fault Zone
and close to a National
Forest
No information is available on the slag management units at these sites. The information presented here is based
only on the environmental setting of the facility.
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6-16 Chapter 6: Primary Copper Processing
Seven of the 10 facilities in this sector provided information on their copper slag management units
and it appears that, industry-wide, engineered ground-water controls are very limited. In addition to
engineered controls, the potential for contaminant releases to ground water and subsequent transport to
exposure points is determined by a number of site-specific factors, such as depth to ground water, precipitation
and net recharge, the presence of intervening confining layers/aquifers, and the distance to downgradient
drinking water wells. Considering these factors, the potential for contaminants to migrate into ground water
is high at two facilities (White Pine and Hurley) and the potential for exposure to this contamination appears
high at one facility (Hurley). The potential for contaminant migration and exposure at the other facilities is
low to moderate, as summarized below.
• At the ASARCO/E1 Paso, Playas, and Phelps Dodge/El Paso facilities, the potential for
slag contaminants to infiltrate into the underlying aquifers is significantly limited by low
precipitation (20 to 26 cm/year) and very low net recharge (0 to 0.5 cm/year).
Furthermore, the slag pile at the Phelps Dodge/El Paso facility is lined with asphalt,
which provides limited control, and the ground water at this site is very deep (76
meters). Even if ground-water releases were to occur at these facilities, the potential
for current drinking water exposures is low because there are no known downgradient
drinking water wells within 1.6 km (1 mile) of the facilities.
• Ground-water releases from the slag piles at Claypool and Hayden due to infiltrating
rainwater are also limited by low net recharge (i.e., 1 to 2.5 cmtyear) at these facilities.
At the Claypool facility, because a part of the slag is submerged in liquids, there may
be a greater potential for contaminants to leach into the subsurface, but the useable
aquifer at this facility is very deep (at least 91 meters below the land surface) and thus
somewhat protected. If there is a release, current drinking water exposures are possible
at Claypool because a large number of people (9,500) rely on a municipal drinking
water well 1.2 km downgradient of the facility. According to the Hayden facility's survey
response, ground water is not used for any purpose within 1.6 km (a mile) of the facility.
• The potential for releases from the slag piles to ground water is relatively high at White
Pine and Hurley. At the White Pine facility, high rainfall (73 cm/year) and high net
recharge (18 cm/year) indicate that, despite the clay layer beneath the waste pile, some
amount of seepage from the pile could migrate to the moderately shallow aquifer (6 to
12 meters deep). Current drinking water exposures are unlikely at this facility because,
to the best of EPAs knowledge, there are currently no downgradient wells within mile.
Releases to ground water could, nevertheless, restrict the potential future uses of the
aquifer. Although net recharge at the Hurley facility is small (5 cm/year) and the
ground water is relatively deep, the permeable subsurface (60 percent sand, 30 percent
silt) may allow leachate caused by infiltrating rainwater to migrate to ground water.
Once in ground water, any contamination could migrate in a largely undiluted and
unretarded fashion in solution cavities that may exist in the karst underlying the site.
Potential drinking water exposures could occur at the nearest downgradient well located
less than 100 meters from the Hurley facility.
Using only data on environmental settings, EPA evaluated the ground-water release, transport, and
exposure potential of the three facilities that did not provide information on their slag management units.
Based on limited data, it appears that the ground-water release, transport, and exposure potential is low at
these three facilities.
• At San Manuel, releases to ground water from the slag are not likely because there is
essentially no recharge to the aquifer at this location.
• At the Garfield facility, factors that limit the formation and migration of leachate from
the slag management unit to the uppermost useable aquifer include the relatively low
precipitation (40 cm/year) and net recharge (0.7 cm/year), and the large depth to the
useable aquifer (90 meters) that is overlain by clay. The potential for current human
health impacts from ground-water contamination is expected to be minimal because, to
the best of EPA's knowledge, there are currently no drinking water wells in the useable
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Chapter 6: Primary Copper Processing 6-17
aquifer within 1.6 km (1 mile) downgradient of the facility. Shallow ground water is
hydraulically connected to the Great Salt Lake and is highly saline (not useable). Any
leachate from the slag, however, could restrict the potential future uses of the aquifer
as a resource.
At the Amarillo facility, there is a potential for contaminants to migrate into shallow
ground water because there is a moderate net recharge (10 cm/yr) and permeable
subsurface. However, the potential for drinking water exposure is low because the
useable aquifer is very deep, 73 meters below the facility.
Surface Water Release, Transport, and Exposure Potential
Constituents from copper slag could, in theory, enter surface waters by migration of slag leachate
through ground water that discharges to surface water, or direct overland (stormwater) run-off of dissolved
or suspended slag materials. The concentrations of several constituents detected in copper slag leachate tests
(lead, copper, arsenic, molybdenum, cadmium, and to a lesser extent, mercury, iron, barium, chromium,
manganese, and zinc) confirm that the potential exists for slag contaminants to migrate into surface water in
a leached form. The potential for overland release of copper slag particles to surface waters is limited
considerably by the generally large size and the glassy form of the slag: the solidified mass of slag as well as
the large chunks of crushed slag are not readily eroded. A small fraction of the slag material, however, may
consist of fragments that are small enough to be credible. Only panicles that are 0.1 mm or less in size tend
to be appreciably credible,16 and only a very small fraction of the copper slag solids are expected to be in
this size range.
Exhibit 6-6 summarizes the characteristics of each of the ten copper facilities that affect the surface
water release, transport, and exposure potential of copper slag. Based on environmental settings of the
facilities and the presence of stormwater run-on/run-off controls at the copper slag management units, the
potential for surface water contamination and human exposure due to releases from copper slag at the ten
facilities can be summarized as follows:17
• Copper slag piles at Claypool and Hurley have a low potential for causing surface water
contamination because the facilities are very far from any streams, rivers, or lakes (at
least 24 km).
• At Phelps Dodge/El Paso and Playas, overland releases are limited by low precipitation
and gentle topographic slopes in the areas, as well as stormwater run-off controls at
Phelps Dodge/El Paso. Episodic releases are not of concern because neither facility is
located in a 100-year floodplain or in areas prone to high snow accumulation and
sudden snow-melts. Given the very low potential for ground-water contamination at
these sites, it is very unlikely that any contaminants originating from on-site slag
management units could seep through ground water and discharge into the Rio Grande
river located 550 meters from Phelps Dodge/El Paso or Playas Lake located 480 meters
from the Playas facility.
• The potential for overland releases to surface water at the Hayden facility is limited by
moderate rainfall (50 cm/year), gentle topographic slope, and the presence of
stormwater run-on/run-off controls. Releases to the nearby Gila River could occur,
however, by seepage of contaminants to the surficial aquifer that may discharge to the
river, although there appears to be a low potential for shallow ground-water contamina-
tion at this facility (see above). Because the river has a moderate flow rate (170 mgd),
any seepage entering the river will be only moderately diluted. The potential for human
16 As indicated by the soil credibility factor of the USDA's Universal Soil Loss Equation.
17 For three facilities that did not provide information on their temporary slag storage or slag cooling units, the copper slag was
assumed to be temporarily accumulated in relatively small slag piles or pits. This assumption may have the effect of overestimating risks
because releases are controlled solely by environmental conditions under this scenario.
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6-18 Chapter 6: Primary Copper Processing
exposures to any surface water contamination caused by the Hayden facility is currently
minimal because the Gila River is not used for drinking water within 24 km down-
stream.
Assuming there are no stonnwater run-on/run-off controls at the San Manuel facility's
slag pits, there is a potential for overland releases to the San Pedro River located 790
meters away because of the moderate rainfall (50 cm/year) and moderately steep slope
(2 to 6%) in the area. Releases via seepage of contaminants through ground water are
not expected because there is essentially no recharge to ground water. Any surface
water contamination that is not sufficiently diluted could threaten aquatic life and
restrict potential beneficial uses of the river because the river's low flow rate (0.08 mgd)
will not rapidly dilute contaminants. Currently, there are no drinking water intakes
from the river within 24 km.
At the Amarillo facility, it is possible for slag contaminants to migrate through shallow
ground water that may discharge to a nearby playa lake because of the moderate rainfall,
moderate net recharge, and permeable subsurface in the area (i.e., factors that enable
leachate from the slag pile to migrate to shallow ground water). Routine and episodic
overland releases are less likely because the rainfall is moderate, and the facility is not
located in a 100-year Qoodplain. Water is present in the lake only intermittently, but
when present, the water may be used for livestock watering.
The Garfield facility is located approximately 300 meters from the Great Salt Lake.
Routine overland releases of slag contaminants to the lake are limited by the gentle
topographic slope (0 to 2%) and the relatively low amount of precipitation in the area
(40 cm/year). Episodic overland releases could occur, however, in the event of a flood
(the facility is located in a 100-year floodplain) and sudden snow-melt (maximum snow
accumulation is 102 cm). It is also possible for slag contaminants to reach the lake by
seeping through ground water, although the potential for contaminant migration via
ground water appears low. Any releases to the Great Salt Lake from the slag at this
facility have a low potential for adversely affecting human health because the lake is not
used for drinking water.
The potential for release to surface water is relatively high at the ASARCO/E1 Paso
facility, overland releases from the slag piles to the Rio Grande river (76 meters from
the facility) have been documented (see damage cases section). Any contaminants
reaching the river are likely to be diluted in the river's large flow (520 mgd). If
sufficient dilution did not occur, the contamination could threaten aquatic life and the
potential beneficial uses of this river, as well as pose human health risks, because there
is a drinking water intake that serves almost 500,000 people approximately 4.3 km
downstream of the facility.
The potential for release of contaminants to surface water is also relatively high at the
White Pine facility. Releases via seepage of contaminants through ground water could
occur at White Pine because, as discussed above, some seepage from the pile could
migrate to the shallow aquifer that probably discharges to the river. Although unlikely,
episodic overland releases to the nearby river located 120 meters from the facility could
also occur due to sudden snow-melts because the facility is located in an area with high
snow accumulation (94 cm maximum). Routine overland releases, however, are limited
by stonnwater run-on/run-off controls and the moderate precipitation (73 cm/year) and
slope in the area. Current human exposures to any surface water contamination caused
by the White Pine facility are possible because there is an intake at a point 5.5 km
downstream.
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Chapter 6: Primary Copper Processing 6-19
Air Release, Transport, and Exposure Potential
Because all of the constituents of concern are nonvolatile, copper slag contaminants can only be
released to air in the form of dust particles. Dust can be either blown into the air by wind or suspended in
air by slag dumping and crushing operations. Factors that affect the potential for such airborne releases
include the particle size of copper slag, the height and exposed surface area of the slag piles, the slag moisture
content, the use of dust suppression controls, and local wind speeds. The potential for exposure to airborne
dust depends on the proximity of the slag piles to people.
The form of copper slag -- a solidified glassy mass that, even when crushed, consists of large particles
such as gravel or cobbles -- significantly limits the potential for release of airborne dust. In general, particles
that are <.100 micrometers (/Lira) in diameter are wind suspendable and transportable. Within this range,
however, only particles that are <30 /im in diameter can be transported for considerable distances downwind,
and only particles that are <.10 /u,m in diameter are respirable. The vast majority of copper slag is substantially
larger than 100 ju,m and thus should not be suspendable, transportable, or respirable. It is likely that only a
very small fraction of the slag will be weathered and aged (or crushed) into smaller particles that can be
suspended in air and cause airborne exposures and related impacts.
Other factors that affect the potential for airborne release and exposure vary on a site-specific basis,
though not to a large extent, as follows:
• At the Hayden, Hurley, and Claypool facilities, the slag piles range from approximately
6.9 to 30 hectares (17 to 64 acres) in area and are 12 to 46 meters high. These piles are
not covered with either vegetation or a synthetic material, and the facilities do not use
any dust suppression controls, such as sprinkling water on the piles. The number of
days with rain, which may suppress dust, is also small (43 to SO days/yr). As a result,
the surfaces of the slag piles are expected to be dry most of the time. Although there
are surely short term gusts of stronger winds, average wind speeds at these facilities
range from 3.4 to 4.8 m/s, which are strong enough to produce wind erosion of any fine
particles. Any windblown dust could lead to potential exposures at Hayden, Hurley,
and Claypool because at all three facilities, the nearest residence in a predominant wind
direction is less than 100 meters away and the population within 1.6 km (1 mile) ranges
from 1,000 to 5,500.
• At the Playas facility, the potential for airborne release is similar to the three facilities
discussed above. However, the potential for exposures is lower because the nearest
residence is 3.7 km away and there is no population within 1.6 km.
• The slag pile at the White Pine facility covers an area of 60 acres, is 3 meters high, and
is uncovered. Although the pile is not currently watered for the purpose of dust
suppression, there is a moderate number of days that have a small amount of
precipitation (116 days/yr) that should help keep the slag moist part of the time.
Average wind speeds range up to 4.7 m/s, though stronger winds occur on a short term
basis. If airborne dust is released, it could lead to potential exposures at the nearest
residence 730 meters from the facility, and could result in 1,200 people within 1.6 km
(1 mile) of the facility being exposed.
• At the Asarco/El Paso and Phelps Dodge/El Paso facilities, the slag piles are relatively
small (6 and 1 meter high, covering 0.8 hectares and 809 m2 (2 and 0.2 acres)), making
the exposed area of the piles much smaller than the piles at the other facilities.
Nevertheless, the small number of days of precipitation to help keep dust down (41
days/yr) and average wind speeds of up to 5.1 m/s, which are strong enough to produce
wind erosion of any fine particles, could allow airborne dusting. Both facilities have a
residence within 100 meters of their boundaries where potential exposures could occur.
There are 40,000 people living within 1.6 km (1 mile) of the Phelps Dodge plant and
roughly 500 people within this distance of the Asarco facility.
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6-20 Chapter 6: Primary Copper Processing
• For the three facilities that did not provide information on their slag management units
(Garfield, San Manuel, and Amarillo), factors such as low number of days of
precipitation (47 to 89 days/yr) and average wind speeds of 4.8 to 6.6 m/s, which are
strong enough to blow fine particles into the air, indicate that airborne releases could
occur. All three facilities have a residence within 1.6 km (1 mile) of their borders where
potential exposures could occur. The potential for exposure is highest at Garfield
(which has 10,000 people within 1.6 km and the nearest residence located 900 meters
away) and at San Manuel (which has 5,000 people within 1.6 km and the nearest
residence located 330 meters away). At the Amarillo facility, on the other hand, there
are only 5 people within 1.6 km of the facility and the nearest residence is 760 meters
away.
Proximity to Sensitive Environments
As summarized in Exhibit 6-6, seven of the ten copper facilities that generate copper slag are located
in or near environments that are either vulnerable to contamination or have high resource value.
• The Playas facility is located within 9 miles of a habitat for an endangered species, the
New Mexico Ridge-Nosed Rattlesnake. Given this distance from the site, releases of
copper slag contaminants from the facility are not likely to affect this habitat.
• The Asarco/El Paso, Garfield, and Hurley facilities are located in 100-year floodplains,
which creates the potential for large, episodic releases caused by flood events (although
such releases are generally unlikely).
• The Garfield facility is located in a wetland area (defined here to include marshes,
swamps, and bogs). Wetlands are commonly entitled to special protection because they
provide habitats for many forms of wildlife, purify natural waters, provide flood and
storm damage protection, and afford a number of other benefits.
• The Hurley facility is located in an area of karst terrain, characterized by sinkholes and
underground cavities developed in water-soluble rock (such as limestone or dolomite).
Solution cavities could permit any ground-water contamination originating from the on-
site slag to migrate in a largely unattenuated and undiluted fashion.
• The White Pine facility is located in a National Forest, and the Claypool facility is
located within a mile of a National Forest Any contamination originating from slag at
these sites could have an adverse effect on the habitats and resources provided by these
forests.
• The White Pine, Claypool, Phelps Dodge/El Paso, Hurley, and Playas facilities are
located in fault zones. This creates the potential for damage to containment systems
for slag piles at these sites in the unlikely event of an earthquake.
Risk Modeling
Based on the preceding analysis of the intrinsic hazard of copper slag and the potential for slag
contaminants to be released into the environment, the Agency ranked copper slag as having a relatively high
potential to cause human health and environmental risks (compared to the other mineral processing wastes
studied in this report). Therefore, the Agency used the model "Multimedia Soils" (MMSOILS) to estimate
ground-water, surface water, and air pathway risks caused by the management of copper slag. Rather than
model all ten sites that generate and manage the slag individually, EPA modeled a hypothetical composite site
that consists of selected features from three different sites. In particular, EPA modeled:
• The median constituent concentrations in copper slag solids as measured at the facility
at Garfield, UT, and the median constituent concentrations in copper slag leachate as
measured at the facility in Playas, NM. In general, the concentrations of most
constituents measured in the slag and slag leachate at these facilities were higher than
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Chapter 6: Primary Copper Processing 6-21
those measured at other facilities. The median concentrations at Garfield and Playas,
however, are only slightly greater than the medians observed elsewhere and thus
reasonably represent copper slag across the industry.
• The slag quantity, management practice, and environmental/exposure setting at the
facility in White Pine, MI. Of the ten facilities that generate and manage the slag, this
facility maintains one of the largest slag piles and has environmental and exposure
characteristics most likely to lead to high risks. These characteristics include the highest
net recharge of all ten sites, a relatively shallow water table, a useable aquifer beneath
the site, a relatively nearby and small stream that may be used for drinking water, and
relatively nearby residents that could be exposed to windblown dust. Although the slag
pile at White Pine is equipped with stonnwater run-on/run-off controls, EPA
conservatively modeled the pile as if it had no controls to limit erosion.
By combining these generally typical waste stream contaminant concentrations with a set of "conservative"
environmental and exposure characteristics into one modeling scenario, the Agency believes that the risk
estimates presented below represent a reasonable upper bound of actual risks at the ten active primary copper
facilities.
Ground-Water Risks
Using the combined site features as described above, EPA modeled potential releases to ground water
from a hypothetical copper slag pile. EPA considered in this analysis the potential releases of arsenic,
cadmium, chromium, and molybdenum, which are the primary constituents of potential concern through the
ground-water pathway based on the analysis of copper slag leachate. In addition, EPA modeled the risks
caused by potential releases of lead to ground water, because along with cadmium, lead was detected in EP
leach tests in concentrations that exceeded the EP toxicity criterion. The Agency predicted the concentrations
of these constituents at the following locations downgradient from the slag pile: the facility property boundary
(150 meters), the nearest surface water body (120 meters), and, to analyze how far a contaminant plume might
spread, the distances of 50 and 500 meters. At each of the locations, the Agency compared the predicted
contaminant concentrations to cancer risk levels, threshold concentrations that could cause noncancer effects,
drinking water maximum contaminant levels (MCLs), and guidelines for irrigation and livestock waters
recommended by the National Academy of Sciences (NAS).
All of the Agency's predicted concentrations of arsenic, cadmium, chromium, molybdenum, and lead
in ground water were at least two orders of magnitude below the various criteria, even at the closest point
modeled (50 meters downgradient from the slag pile). The predicted concentration of arsenic in ground water
50 meters downgradient and at the property boundary, where the water conceivably could be ingested by a
member of the general public, would cause a lifetime cancer risk of less than IxlO"10 (i.e., the chance of getting
cancer would be less than one in ten billion if the water was ingested over a 70-year lifetime). Only arsenic
and cadmium were predicted to migrate to the water table within the modeling time frame that was considered
(200 years). EPA predicted that it would take chromium and molybdenum roughly 470 years to migrate from
the slag pile down to the water table, while lead released from the slag pile was predicted to be bound up in
the unsaturated zone for over 1,000 years.
Surface Wafer Risks
To evaluate surface water risks, EPA modeled a 1.8 m3/sec (65 ft3/sec) stream located 120 meters from
a 24 hectares (60-acre) slag pile, which are roughly the conditions that currently exist at the facility in White
Pine, MI. Considering the annual loading of contaminants to the stream via ground-water seepage and
erosion, the Agency predicted the surface water concentrations of the following constituents after they have
been fully mixed in the stream's annual average flow: arsenic, cadmium, chromium, copper, iron, lead, mercury,
molybdenum, nickel, and zinc. EPA then compared the predicted concentrations of these constituents to
cancer risk levels, noncancer effect thresholds, MCLs, freshwater ambient water quality criteria (AWQCs) for
chronic exposures, and the NAS recommended guidelines for livestock and irrigation waters. Note that this
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6-22 Chapter 6: Primary Copper Processing
approach does not account for removal, via treatment, of constituents in drinking water, and is thus
conservative for that pathway.
EPAs predicted concentrations of cadmium, chromium, nickel, and zinc in the stream were at least
two orders of magnitude below the various criteria. The estimated concentration of mercury also did not
exceed any of the criteria, although it was within a factor of 0.7 times the AWQC.18 The estimated
concentrations of arsenic, copper, lead, iron, and molybdenum exceeded at least one of the criteria. All of
these constituents were predicted to migrate into the stream by erosion of fine particles from the slag pile
(seepage of contaminants into ground water with subsequent discharge into the stream resulted in a negligible
pollutant loading). In particular:
• The estimated concentration of arsenic in the stream would cause a lifetime cancer risk
of 6xlO~5 if ingested over 70 years. This arsenic concentration, however, is two orders
of magnitude below the MCL.
• The predicted concentration of copper equaled the NAS recommended guideline for
irrigation water and exceeded the AWQC by a factor of 65. Research has shown that
if water with copper concentrations in excess of the NAS guideline is used continuously
for irrigation, it could be toxic to plants. Exceedance of the AWQC indicates that the
copper concentrations in waters near copper slag piles could be harmful to aquatic
organisms.
• The estimated concentration of lead exceeded the proposed revised MCL by a factor of
1.1 and the AWQC by a factor of 1.7. This lead concentration could cause a variety of
subtle biochemical and cellular effects if consumed on a long-term basis, and adversely
affect the health of aquatic organisms living in affected waters.
• The estimated concentration of iron exceeded the MCL by a factor of 3.7 and the
AWQC by a factor of 1.1. Concentrations of iron in excess of the MCL could cause
objectionable tastes and stains. Exceedance of the AWQC indicates that the iron
concentrations in waters near copper slag piles could be harmful to aquatic organisms.
• The estimated concentration of molybdenum exceeded the NAS irrigation guideline by
a factor of 2.1. Although molybdenum concentrations in excess of the NAS guideline
have not been shown to be toxic to plants, they can be toxic to animals that forage on
plants irrigated with the water.
Of the constituents that were modeled, only mercury is recognized as having the potential to
biomagnify (concentrate in the tissue of organisms higher in the food chain). However, considering the low
mercury concentrations that were predicted, EPA does not expect adverse effects due to biomagnification.
Cadmium, lead, and zinc (and to a lesser extent, the other constituents) may bioaccumulate in the tissue of
freshwater fish that could be consumed by people. However, based on a "worst-case" exposure analysis using
the predicted surface water contamination caused by copper slag, EPA does not believe that the ingestion of
fish from the affected water would pose a health threat.
The Agency believes that these estimates reasonably represent the conditions that could occur at the
facility in White Pine, MI if the on-site slag pile was not equipped with stormwater run-off controls. Except
for the contaminant concentrations in the slag and slag leachate, which were measured at the Garfield and
Playas facilities, all of the site-specific conditions that were modeled are generally representative of the White
Pine facility. Furthermore, as discussed above, the concentrations that were modeled are approximately equal
to median concentrations measured in copper slag at all tea facilities (Le., they are reasonably representative
of the concentrations observed across the industry). However, because the slag pile is equipped with run-off
controls, the Agency believes the above estimates represent conservative upper bound risks at White Pine, as
18 This estimated mercury concentration in the stream is considered very conservative because it is based on a non-detected mercury
concentration in copper slag solids. For the purpose of this analysis, EPA assumed that mercury is present in the slag solids in *
concentration that equals the full detection limit.
-------
Chapter 6: Primary Copper Processing 6-23
well as at the other nine active copper facilities. The other facilities are located in much more arid and remote
areas where there is a smaller potential for contaminant releases and exposures via the surface water pathway
(as described above in the analysis of release, transport, and exposure potential).
Air Risks
EPA modeled the release of windblown dust from the slag pile and the associated inhalation risks of
a hypothetical maximum exposed individual assumed to live 90 meters away in the predominant wind direction.
The distance of 90 meters was chosen because, based on an analysis of the population distribution around the
ten active copper facilities, it is a typical "close" distance between copper slag piles and nearest residences.
For this distance, the Agency predicted the airborne concentrations and inhalation risks of arsenic, chromium,
and nickel, which are all carcinogens through the inhalation pathway (chromium was conservatively assumed
to exist in the carcinogenic hexavalent form). In general, the Agency's approach for modeling releases was
very conservative because it assumed that there is an "unlimited reservoir" of fine particles that can be blown
into the air from copper slag piles. As discussed previously, copper slag actually has limited wind erosion
potential because the vast majority of slag on the piles consists of large particles that are not suspendable or
transportable at typical wind speeds.
Even with this conservative approach, risks caused by the inhalation of dust from the hypothetical
copper slag pile were predicted to be low. At the hypothetical residence assumed to be 90 meters from the
slag pile, the total lifetime cancer risk caused by the inhalation of arsenic, chromium, and nickel was estimated
to be IxlO"6. Considering the conservative modeling approach that was used, EPA believes that this estimate
represents a reasonable upper bound of the inhalation risks caused by copper slag piles at the ten active facilit-
ies.
6.3.2 Risks Associated With Copper Slag Tailings
Any potential danger to human health and the environment from copper slag tailings depends on the
presence of toxic constituents in the tailings that may pose a risk and the potential for exposure to these
constituents based on facility setting and management practices. These factors are discussed separately below.
Constituents of Concern
Using the same process outlined above for copper slag, EPA identified chemical constituents in the
copper slag tailings that may pose a risk by collecting data on the composition of slag tailings, and evaluating
the intrinsic hazard of the slag tailings' chemical constituents.
Data on Copper Slag Tailings Composition
EPA's characterization of copper slag tailings and its leachate is based on data from two sources: (1)
a 1989 sampling and analysis effort by OSW; and (2) industry responses to a RCRA §3007 request in 1989.
These data provide information on the concentrations of 20 metals, radium-226, uranium-238, and sulfate in
total solids and/or leach test analyses. Two of the three facilities that generate the slag are represented by
these data: Kennecott in Garfield, Utah, and Magma Copper Company in San Manuel, Arizona.
Concentrations in total samples of the slag tailings are generally consistent for most constituents
across all data sources and facilities. The exceptions are for lead - concentrations of lead in tailings samples
from the two facilities differed by over three orders of magnitude; and molybdenum - the concentration of
molybdenum in slag tailings from the Garfield facility was three orders of magnitude higher than the
concentration measured in tailings from the San Manuel facility. Concentrations from leach test analyses of
the slag tailings are consistent across the data sources, types of leach tests (Le., EP, SPLP, and TCLP), and
facilities.
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6-24 Chapter 6: Primary Copper Processing
Identified Constituents of Concern
Exhibits 6-7 and 6-8 present the results of the comparisons for copper slag tailings total analyses- and
leach test analyses, respectively, to the risk screening criteria. These exhibits list all constituents for which
sample concentrations exceed a screening criterion.
From the 21 constituents analyzed in copper slag tailings solids, only arsenic, chromium, and lead
concentrations exceed the screening criteria (see Exhibit 6-7). Arsenic and chromium concentrations in the
slag tailings exceed the inhalation pathway screening criteria. This indicates that if the slag tailings are blown
into the air as dust and inhaled in a concentration that equals the National Ambient Air Quality Standard for
paniculate matter, these two constituents may be present in concentrations that could cause a cancer risk of
greater than 1 x 10~5. Arsenic and lead concentrations in the tailings solids exceed the incidental ingestion
screening criteria. This means that, if the tailings are incidentally ingested on a routine basis (e.g., if children
playing on abandoned waste piles inadvertently ingest the tailings), arsenic would pose a cancer risk of 1 x 10"5
or more, while lead could cause adverse noncancer effects. All three constituents were detected in more than
90 percent of the samples analyzed at concentrations exceeding the screening criteria. All three constituents
were also detected in concentrations that exceed the screening criteria by a factor of ten or more.
Based on a comparison of leach test concentrations of 22 constituents to the surface and ground-water
pathway screening criteria (see Exhibit 6-8), only 7 constituents (copper, molybdenum, arsenic, lead, silver,
nickel, and mercury) were detected at levels above the screening criteria. All of these constituents are metals
or other inorganics that do not degrade in the environment. Arsenic exceeded the screening criteria in 12 out
of 13 samples, and the highest measured arsenic concentration exceeds the drinking water criterion by a factor
of 900. Nickel and mercury, on the other hand, were found to exceed the screening criteria in only 20 to 30
percent of the samples analyzed, and only by a factor of 2 or less. Despite these exceedances of the screening
criteria, no constituents were detected in the leachate in concentrations that exceed the EP toxicity regulatory
levels.
These exceedances indicate the potential for the following types of impacts under the following
conditions:
• Concentrations of arsenic and copper in the slag tailings leachate are high enough that,
if the leachate is released to ground water and diluted only by a factor of 10 during
migration to a drinking water well, long-term ingestion of the water could cause adverse
health effects.
• Concentrations of copper, arsenic, silver, nickel, and mercury in slag tailings leachate
could present a threat to aquatic ecological receptors if it migrates (with a 100-fold
dilution) to surface waters.
• If the leachate is released and diluted by a factor of ten or less, copper, molybdenum,
arsenic, and lead concentrations could exceed drinking water maximum contaminant
levels or guidelines for irrigation water.
These exceedances of the risk screening criteria, by themselves, do not prove that copper slag tailings
pose a significant risk. The criteria exceedances outlined above only indicate that the tailings may present a
hazard under a set of very conservative, hypothetical exposure conditions. To determine the risks associated
with copper slag tailings, therefore, EPA proceeded to the next step of the risk analysis to examine the actual
release, transport, and exposure conditions that exist at the facilities that actively generate and manage the
tailings.
Release, Transport, and Exposure Potential
The following analysis considers the baseline hazards of copper slag tailings at the three plants of
interest in 1988. For this analysis, EPA did not consider the hazards of off-site disposal or use of the tailings
because the tailings currently are never disposed of or used off-site (although slag tailings have been used off-
site for construction purposes in the past and conceivably could be used again in the future). Alternative
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Chapter 6: Primary Copper Processing 6-25
Exhibit 6-7
Potential Constituents of Concern in Copper Slag Tailings Solids^
Potential
Constituent*
of Concern
Arsenic
Chromium
Lead
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
26727
8/9
27/27
Human Hearth
Screening Criteria04
(ngestion*
hihatation"
Inhalation*
Ingestion
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
26/27
26/27
8/9
25/27
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
1 12
1 12
1 12
1 12
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10"5 lifetime cancer
risk; others are based on noncancer effects.
Exhibit 6-8
Potential Constituents of Concern in Copper Slag Tailings Leach ate(a)
Potential
Constituents
of Concern
Copper
Molybdenum
Arsenic**
Lead'6*
Saver*"'
Nickel10'
Mercury
No. of Tiims
Constituent
Detected/No, of
Analyses
for Constituent
3/3
2/2
12/13
9/13
9/13
2/11
1/3
Screening Criteria*11'
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Human HMtti
Resource Damage
Aquatic Ecologies}
Resource Damage
Aquatic Ecological
Aquatic Ecological
Aquatic Ecological
No. of Analyse*
Exceeding Criteria/
No. of Analyse* for
Constituent
2/3
2/3
3/3
2/2
12/13
fl/13
7/«
9/13
8/13
2/11
1/3
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
2/2
2/2
2/2
2/2
2/2
1/2
1/2
2/2
1/2
1 12
1/2
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. Unless otherwise
noted, the constituent concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. 'Human health* screening criteria
noted with an '*' are based on a 1x10"* lifetime cancer risk; others are baaed on noncancer effects.
(c) Data for this constituent are from SPLP leach test results.
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6-26 Chapter 6: Primary Copper Processing
practices for managing the tailings are discussed in Section 6.5. In addition, the following analysis does not
consider the risks associated with variations in waste management practices or potentially exposed populations
in the future, because of a lack of information on possible future conditions.
Ground-Water Release, Transport, and Exposure Potential
As discussed in the preceding section, EPA and industry test data show that several constituents are
capable of leaching from copper slag tailings in concentrations that exceed the risk screening criteria.
Considering only those constituents that are expected to be mobile in ground water (given the existing tailings
management practices and neutral pH of the leachate), slag tailings contaminants that pose the primary
potential threat are arsenic, mercury, and molybdenum. The ground-water release and transport potential of
copper slag tailings at the three facilities depends on site-specific management practices and environmental
settings.
The single tailings pond at the White Pine facility is underlain by recompacted local clay and in-situ
clay that helps limit leachate from the pond reaching the underlying aquifer. Nevertheless, the large quantity
of standing liquid in the pond (the pond is 16 meters deep and covers 972 hectares (2,400 acres)) produces
a considerable hydraulic head that could drive leachate from the tailings into the subsurface. Furthermore,
any constituents released from the units could be transported readily through the 6 to 12 meters of fractured
rock that lies between the pond and the stratum identified as the uppermost aquifer. Any ground-water
contamination from the unit, especially arsenic contamination, could restrict the potential future uses of this
aquifer. However, the potential for current human health impacts from ground-water contamination is
expected to be minimal because, to the best of EPAs knowledge, there are currently no drinking water wells
within a mile downgradient of the facility, and the aquifer is not being used as a municipal drinking water
supply.
At the Garfield facility, fresh slag tailings are discharged as a slurry to a tailings impoundment. This
impoundment is now about 46 meters above the original grade and covers about 2300 hectares (5,600 acres).
Dried tailings are used to form a benn that creates the impoundment into which the slurried tailings are
discharged. In theory, tailings contaminants could be released to ground water by seepage of the ponded water
or by rain water infiltrating through dry areas of the impoundment However, factors that limit the migration
of leachate from the tailings impoundment to the uppermost useable aquifer include: the precipitation (40
cmtyear) and net recharge in the area (0.7 cm/year) are relatively low, and the aquifer is very deep (i.e., 90
meters) and is primarily overlain by a zone of impermeable clay. In addition, the potential for current human
health impacts from any contamination from the tailings impoundment, should it occur, appears minimal
because there are currently no drinking water wells within a mile downgradient of the facility to the best of
EPAs knowledge. The shallow ground water at the site is saline (and generally unuseable) because it is
hydraulically connected with the Great Salt Lake.
The five tailings ponds at the San Manuel plant are not lined and have no leachate collection systems
or other controls to limit releases to ground water. These ponds, which are 40 to 60 meters deep and cover
anywhere from 140 to 330 hectares (350 to 820 acres), may have quantities of supernatant liquids that
potentially provide sufficient hydraulic head to drive contaminants to the underlying aquifer. However, the
uppermost useable aquifer beneath this facility is located 140 meters beneath the tailings ponds and is
separated by an intervening alluvial aquifer. Ground-water monitoring data indicate that contamination of
the useable aquifer has occurred at this site. Sulfate, which is present in the tailings but was not measured
in the tailings leachate, has been detected downgradient of the facility at levels exceeding drinking water
standards. (The Agency's review of State and EPA regional files did not provide evidence that this ground-
water contamination is attributable to slag tailings management.) Any contaminant migration from the slag
tailings into the uppermost useable aquifer has a high potential for posing current human health risks and
restricting potential future uses of the ground water because approximately 4,000 people rely on the aquifer
for drinking water from a municipal well located only 150 meters downgradient from the facility.
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Chapter 6: Primary Copper Processing 6-27
Surface Water Release, Transport, and Exposure Potential
Constituents of concern in copper slag tailings theoretically could enter surface waters by migration
of slag tailings leachate through ground water that discharges to surface water, or by direct overland
(stormwater) run-off of dissolved or suspended slag tailings constituents. As discussed above, the following
constituents that are mobile in ground water leach from the slag tailings at levels that potentially could pose
human health or aquatic ecological threats or damage surface water resources: molybdenum, arsenic, and
mercury. The other constituents in slag tailings could potentially migrate to surface water via overland
erosion.
At the White Pine facility, excess water in the tailings pond, which could contain entrained tailings
solids, is discharged directly to a river located 120 meters away via a NPDES-pennitted outfall. It is also
possible for the tailings contaminants to migrate to the river via ground-water seepage. Water quality
monitoring in the river has identified cadmium, selenium, copper, and total dissolved solids concentrations in
excess of drinking water standards, as well as cadmium, copper, lead, selenium, and zinc levels that exceed the
ambient water quality criteria. The slag tailings could be a contributor to this contamination because, based
on EPA and industry test data, copper and lead are readily teachable from the tailings. The river near this
facility has a relatively low dilution capacity (flow of 42 mgd), and potential drinking water exposures could
occur at a water supply intake 5 km downstream (it appears that 25 people rely on this intake). Therefore,
if not sufficiently diluted, any contaminants entering the river could potentially harm aquatic life, restrict the
future uses of the river as a resource, and pose health risks to existing populations.
At the Garfield facility, the potential for routine overland releases to the Great Salt Lake are limited
by the distance to the lake (300 meters), stormwater run-on/run-off controls, the gentle topographic slope (0
to 2 percent), and the relatively low amount of precipitation in the area (40 cm#r). Although unlikely,
episodic overland releases could occur in the event of a flood (the facility is located in a 100-year floodplain).
Release of contaminants to surface water is also possible by infiltration of contaminants to the surficial aquifer
that is hydraulically connected with the lake. Releases to Great Salt Lake have a low potential for adversely
affecting human health because the lake is not used for drinking water.
Contaminants from slag tailings ponds at the San Manuel plant possibly could migrate to the San
Pedro River located 790 meters away via seepage to the alluvial aquifer that may discharge to the river. As
discussed in the preceding section on ground water, seepage to the surficial aquifer is possible due to the
teachability of the waste, lack of ground-water controls, and standing liquids in the ponds. Overland run-off
of the tailings could only occur in the event of a major storm causing overflow of tailings from the ponds.
Such overflow is unlikely, however, because of the plant's stormwater run-on/run-off controls, low precipitation
(50 cm/year) available for run-off, and moderate topographic slope (2 to 6%). The San Pedro River near this
facility has a low flow rate (0.08 mgd), which provides only a limited dilution capacity. The river water is used
for livestock watering approximately 1.2 km downstream of the facility, but currently, there are no other
consumptive uses within 24 km downstream. If not sufficiently diluted, contaminants reaching the river could
pose a risk to aquatic organisms and restrict potential uses of the river.
Air Release, Transport, and Exposure Potential
Because all of the constituents of potential concern in copper slag tailings are nonvolatile, the
contaminants can be released to air only in the form of dust particles. As presented above, only arsenic and
chromium are present in the slag tailings in concentrations that could pose human health risks through
inhalation of respirable particles of slag tailings.
In general, particles that are <. 100 micrometer (/im) in diameter are wind suspendable and
transportable. Within this range, however, only particles that are <. 30 fan in diameter can be transported
for considerable distances downwind, and only particles that are <. 10 /im in diameter are respirable. The slag
tailings consist mainly of particles larger than 100 /im in diameter, and therefore, the majority of the slag
tailings should not be suspendable, transportable, or respirable. The quantity of tailings disposed and the areal
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6-28 Chapter 6: Primary Copper Processing
extent of the disposal areas, however, is such that wind transport of fine tailings material does occur if the
tailings dry OUt.
The potential for dust to be blown into the air from the tailings impoundment at the Garfield facility
is limited because the facility suppresses dust by periodically moving the location of the discharge of the
tailings slurry to keep the surface of the entire impoundment wet. Nevertheless, dusting is possible because
dried tailings are piled up and exposed to the wind around the perimeter of the impoundment and the entire
impoundment may not always remain wet. In addition, the facility is located in an arid area where there is
relatively infrequent rainfall (there are only 89 rainy days/year) and significant evaporation, which is conducive
to dusting. In at least one instance, due to a facility shutdown, a large pan of the tailings pile surface became
dry and tailings dust was released to air whenever the wind speeds exceeded 20 mph. Ambient air quality
monitoring at the facility indicated that the National Ambient Air Quality Standards (24-hour average
concentration) for respirable paniculate matter had been exceeded. Such airborne releases at this facility
could lead to potential exposures at the closest residence, approximately 20 meters from the facility, as well
as exposures to the 10,000 people that live within 1.6 km of the facility.
At the White Pine and San Manuel facilities, the slag tailings are currently submerged in the ponds,
and there are no significant areas of dry tailings from which dust could be blown into the air. The San Manuel
facility, however, is located in a very arid area in which significant evaporation from the tailings ponds is likely
after the ponds are closed. This could allow the surface of the tailings to become dry after closure, allowing
a small fraction of the tailings (i.e., those particles that are smaller than 100 Aim) to be blown in the air as
dust.
Proximity to Sensitive Environments
As discussed in the preceding section on copper slag, the White Pine facility is located in a fault zone,
which creates the potential for damage to slag tailings containment systems in the unlikely event of an
earthquake. The facility is also located in a National Forest; any contamination originating from the White
Pine facility, therefore, could endanger the habitats and resources provided by the forest. The Garfield facility
is located in a 100-year floodplain, which creates the potential for large episodic releases of tailings due to
floods, and in a wetland. Any contamination originating from the Garfield facility could adversely affect the
habitats and special functions provided by the wetland. The San Manuel facility is not located in or within
one mile of an environment that is particularly vulnerable to contamination or has a high resource value.
Risk Modeling
Based upon the evaluation of intrinsic hazard, the descriptive analysis of factors that influence risk,
the risk modeling results for other mineral processing wastes examined in this report, and upon a
comprehensive review of information on documented damage cases (presented in the next section), EPA has
concluded that the potential for slag tailings to impose significant risk to human health or the environment
if managed according to current practice is generally low. Therefore, the Agency has not conducted a
quantitative risk modeling exercise for this waste.
6.3.3 Risks Associated With Calcium Sulfate Sludge
This section discusses the constituents in calcium sulfate sludge that are potentially of concern, and
the potential for exposure to these constituents based on facility setting and management practices.
Constituents of Concern
EPA identified chemical constituents in the calcium sulfate sludge that may pose a risk using the same
process outlined above for copper slag.
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Chapter 6: Primary Copper Processing 6-29
Data on Calcium Sulfate Sludge Composition
EPA's characterization of calcium sulfate sludge and its leachate is based on data from two sources:
(1) OSW's 1989 sampling and analysis effort; and (2) industry responses to a §3007 request in 1989. These
data provide information on the concentrations of 20 metals, ammonia, and nitrate in total and leach test
analyses. Both facilities that currently generate the sludge are represented by these data: Asarco in Hayden,
Arizona, and Kennecott in Garfield, Utah.
Concentrations in total analyses of the calcium sulfate sludge are consistent for most constituents
across all data sources and facilities. Silver concentrations in calcium sulfate sludge at the Garfield facility
(OSW data), however, are more than three orders of magnitude lower than silver concentrations in sludge at
the Hayden facility (industry data). Concentrations from leach test analyses of the calcium sulfate sludge
generally are also consistent across the data sources, types of leach tests (i.e., EP, SPLP, and TCLP), and
facilities. Copper and mercury concentrations in leachate from the sludge as determined by EP leach test
analyses, however, are more than three orders of magnitude higher than the SPLP leach test concentrations.
Identified Constituents of Concern
Exhibits 6-9 and 6-10 present the results of the comparisons for calcium sulfate sludge total analyses
and leach test analyses, respectively, to the screening criteria. These exhibits list all constituents for which
sample concentrations exceed a screening criterion.
Exhibit 6-9
Potential Constituents of Concern in Copper CaS04 Sludge Solids
(a)
Potential
Constituents
of Concern
Arsenic
Lead
Cadmium
Antimony
Silver
Copper
No. of Time*
Constituent
Detected/No, of
Analyses
for Constituent
7/7
9/9
7/9
5/7
5/6
9/9
Human Health
Screening Criteria"*
Inflection"
mhatsHor*"
Inflection
Inhalation*
tngMuon
Inflection
Inflection
Inflection
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
7/7
7/7
7/9
e/s
6/«
5/7
3/«
4/9
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
2/2
2/2
3/3
2/3
2/3
1 /2
t/2
1/3
(a) Constituents listed in this table are present in at lead one sample from at (east one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given cample were assumed not to be present in the cample.
(b) Human health screening criteria are based on exposure via Incidental inflection and inhalation. Human health effects
include cancer rick and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10"5 lifetime cancer
rick; others are based on noncancer effects.
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6-30 Chapter 6: Primary Copper Processing
Exhibit 6-10
Potential Constituents of Concern in Copper CaSO. Sludge Leachate(a)
Potential
Constituent*
of Concern
Arsenic
Selenium
Lead
Cadmium
Copper
Mercury
Nickel
Silver
Zinc
Antimony
Aluminum
Manganese
No. of Time*
Constituent
Detected/No, of
Analyses
for Constituent
8/8
7/8
a/8
8/8
8/8
8/8
1/2
6/8
2/2
1/2
2/2
2/2
Screening Criteria*'
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Hearth
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Aquatic Ecological
Resource Damage
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
8/8
8/8
8/8
7/8
7/8
7/8
8/8
8/8
8/8
7/8
7/8
7/8
7/8
7/8
7/8
4/8
5/8
6/8
1/2
1/2
1/2
5/8
6/8
1/2
1/2
2/2
1/2
2/2
1/2
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
2/2
2/2
2/2
1 12
1 12
1 12
2/2
• 2/2 '
2/2
2/2
2/2
2/2
2/2
2/2
2/2
12
12
12
/2
12
12
1/2
1/2
1/2
1/2
2/2
1 12
2/2
1 12
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. The constituent
concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer riek or noncancer health effects. 'Human health' screening criteria
noted with an '*' are based on a IxlO'5 lifetime cancer risk; others are based on noncancer effects.
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Chapter 6: Primary Copper Processing 6-31
Of the 22 constituents analyzed in total analyses of copper calcium sulfate sludge, only 6 (arsenic,
lead, cadmium, antimony, silver, and copper) are present in concentrations that exceed the conservative
screening criteria. Among these six constituents, arsenic, lead, cadmium, and antimony present the greatest
potential concern because they were detected in most of the samples analyzed (75 to 100 percent), and their
concentrations in most analyses (approximately 66 to 100 percent) exceed the screening criteria. Arsenic, lead,
and cadmium concentrations also exceed the criteria by the widest margins, ranging from 20 to 25,000 times
the criteria.
• Arsenic, lead, cadmium, antimony, silver, and copper concentrations could cause adverse
health effects if a small quantity of the sludge or soil contaminated with it is incidentally
ingested on a routine basis (e.g., if children playing on abandoned sludge disposal areas
inadvertently ingest some of the sludge solids).
• If dust from the sludge is blown into the air in a concentration that equals the National
Ambient Air Quality Standard for paniculate matter, arsenic and cadmium con-
centrations could pose a cancer risk exceeding 1 x 10'5 if inhaled by nearby individuals.
However, as discussed in more detail in the next section, such large releases and
exposures to windblown dust are considered very unlikely given the surface crust that
forms on the dried sludge.
Based on a comparison of EP leach test concentrations of 20 constituents to surface and ground-water
pathway screening criteria (see Exhibit 6-10), 12 constituents (i.e., arsenic, selenium, lead, cadmium, copper,
mercury, nickel, silver, zinc, antimony, aluminum, and manganese) were detected at levels above the criteria.
Arsenic, selenium, and lead were detected in most (if not all) of the samples analyzed in concentrations that
exceed all three screening criteria (i.e., for human health, resource damage, and aquatic ecological threats).
All but aluminum, antimony, and zinc exceed the criteria by a factor of 10 or more; maximum arsenic, copper,
mercury, and selenium concentrations exceed one of the criteria by more than a factor of 100. Arsenic exceeds
the screening criteria by the widest margin, up to a factor of 350,000. Arsenic, selenium, and cadmium were
also measured in EP leachate in concentrations above the EP toricity regulatory levels. All of these
constituents that exceed the screening criteria are persistent in the environment (i.e., they do not degrade).
These exceedances have the following implications:
• If sludge leachate is released to ground water and diluted by a factor of 10 or less during
migration to a drinking water well, concentrations of arsenic, selenium, lead, cadmium,
copper, mercury, nickel, antimony, and zinc in the ground water could cause adverse
health effects if ingested.
• Arsenic, selenium, lead, cadmium, copper, mercury, nickel, silver, zinc, and aluminum
in the calcium sulfate sludge leachate could present a threat to aquatic organisms if it
migrates (with a 100-fold dilution) to surface waters.
• If the leachate" is released to ground water and diluted by a factor of 10 or less, arsenic,
selenium, lead, cadmium, copper, mercury, nickel, silver, zinc, and manganese
concentrations could exceed drinking water maximum contaminant levels or irrigation
guidelines.
Concentrations above the screening criteria do not prove that the sludge poses a significant hazard,
but rather indicate that the sludge could pose risks under a set of very conservative, hypothetical exposure
conditions. To examine the potential for the sludge to pose hazards in greater detail, EPA analyzed the actual
release, transport, and exposure conditions that exist at the two facilities that actively generate and manage
the sludge.
Release, Transport, and Exposure Potential
This analysis considers the baseline hazards of the sludge as it was generated and managed at the two
copper plants of concern in 1988. It does not consider the hazards associated with off-site disposal or use
because the sludge is managed only on-site and is not likely to be disposed or used off-site in the future. In
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6-32 Chapter 6: Primary Copper Processing
addition, the following analysis does not consider the risks associated with variations in waste management
practices or potentially exposed populations in the future because of a lack of information on possible future
conditions.
Ground-Water Re/ease, Transport, and Exposure Potential
The calcium sulfate sludge is a solid material, but is generated as a thick slurry mixed with water (i.e.,
a slurry with a relatively high solids fraction). After being discharged to surface impoundments, the sludge
solids settle out and, in the arid settings of Garfield, UT and Hayden, AZ, the supernatant liquid is generally
lost to evaporation. EPA and industry test data show that 12 constituents are capable of leaching from
calcium sulfate sludge in concentrations above the risk screening criteria. Considering only those sludge
constituents that are expected to be mobile in ground water if released, the contaminants that pose the primary
potential human health and ground-water resource damage threat are arsenic, selenium, cadmium, and
mercury.
The two surface impoundments used to manage the sludge at the Garfield facility hold from 25 to
34 million gallons of the waste sludge. The surface impoundments are underlain by in-situ clay, and the water
table is roughly 8 meters deep. The uppermost useable aquifer is approximately 90 meters beneath the base
of the impoundments. Significant migration of sludge contaminants into ground water at this site appears
unlikely because of the very arid setting - the liquid that is discharged to the impoundment along with the
sludge is expected to quickly evaporate and little precipitation and recharge is available to carry contaminants
into the subsurface. Even if releases from the calcium sulfate sludge at this facility did occur, the potential
for current adverse human health impacts appears low because, to the best of EPAs knowledge, there are no
downgradient public or private wells within 1.6 km.
At the Hayden facility, the impoundment used to manage the sludge is equipped with a synthetic
(asphalt/rubber) liner. In the event of liner failure, seepage could migrate to shallow ground water (located
6 meters beneath the land surface) because the subsurface material is composed mainly of permeable sand (80
percent) with little clay (10 percent). However, the current potential for people to be exposed to such
contamination, if it were to occur, is low because facility personnel report that the aquifer under the site is
not used for drinking water or any other purpose.
Surface Water Release, Transport, and Exposure Potential
Constituents of potential concern in calcium sulfate sludge, in theory, could enter surface waters by
migration of sludge leachate through ground water that discharges to surface water, or by direct overland
(stormwater) run-off of dissolved or suspended sludge contaminants. As discussed above, the following
constituents that are expected to be mobile in ground water leach from the calcium sulfate sludge at levels
above the risk screening criteria: arsenic, selenium, cadmium, and mercury. Other sludge constituents
potentially could migrate to surface waters via stormwater runoff.
The potential for routine overland run-off of the sludge contaminants to surface waters due to
overflow from the sludge management ponds at both facilities is limited by stormwater run-on/run-off controls
at the units, low to moderate precipitation (40 to 50 cm/yr), and gentle topographic slopes at the sites (up to
2 percent). Other site-specific factors include:
• The sludge impoundments at the Garfield facility are located approximately 3300
meters from the Great Salt Lake. Given this great distance, it is unlikely that
contaminants could enter the lake in potentially harmful concentrations via seepage to
ground water. Furthermore, any releases to surface water at this facility have a low
potential for adversely affecting human health because the Great Salt Lake is not used
for drinking water.
• At the Hayden facility, releases to the Gila River located 80 meters away could occur
due to seepage through ground water. There is a potential for seepage from the
impoundment to ground water in the event of a liner failure, as discussed in the section
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Chapter 6: Primary Copper Processing 6-33
above. Contamination of the river could threaten aquatic life in the river, and restrict
its potential use. Risks to current human populations via surface water contamination
are not expected, however, because there are no known consumptive uses of the river
within 24 km downgradient of the facility.
Air Release, Transport, and Exposure Potential
Because all of the constituents of potential concern in the calcium sulfate sludge are nonvolatile, the
contaminants can be released to air only in the form of windblown dust particles. As presented above, only
arsenic and cadmium are present in the sludge in concentrations that exceed the risk screening criteria for
inhalation. Although the sludge consists of very fine particles (0.02 micrometers or less in diameter), which
are highly susceptible to wind erosion, the surface of the sludge dries to form a surface crust that is expected
to limit dusting to a large extent.
At the Garfield facility, one of the ponds is allowed to dry while the other pond receives sludge
discharges in the form of a slurry. The dried sludge is dredged, stabilized, and disposed in an on-site landfill.
During the period that the sludge is dried and exposed to the wind, but before it is dredged and stabilized,
wind erosion is possible although limited by the surface crust that forms on the dried sludge. Once stabilized
and buried, windblown emissions should not be a problem. If there is any dust blown into the air from dried
sludge standing in the impoundment, there is a resident within 100 meters and a total of 10,000 people living
within 1.6 km that could be exposed.
At the Hayden facility, the sludge is accumulated at the bottom of an impoundment in a wet or moist
form. In this form, airborne releases of dust from the sludge should be negligible. However, the facility is
located in a very arid area (Arizona) and the impoundments dry out between wastewater discharges. Dusting
from such a dried, inactive impoundment is possible but, again, the surface crust that forms on the sludge after
it is dried should help to keep the dust down. If any airborne releases were to occur, the nearest resident
(located 90 meters away) as well as the 2^00 people living within 1.6 km could be exposed through the
inhalation pathway.
Proximity to Sensitive Environments
As discussed above, the Garfield facility is in a 100-year floodplain, which creates the potential for
large episodic releases of the sludge due to flood events. The sludge impoundments at the facility, however,
are roughly 3300 meters from the Great Salt Lake and therefore are unlikely to be affected by floods. The
Garfield facility is also in a wetland, which are highly valued because they provide abundant habitat, purify
natural waters, and provide flood and storm damage protection, as well as a number of other functions. The
Hayden facility is not located in or within a mile of an environment that is vulnerable to contamination or has
a high resource value.
Risk Modeling
Although the potential for release and exposure to calcium sulfate sludge contaminants appears to
be generally low based on facility settings and management practices, the intrinsic hazard of the sludge
composition compelled EPA to rank the sludge as having a relatively high potential to cause human health
and environmental risks (compared to other mineral processing wastes studied in this report). Therefore, EPA
used the model "Multimedia Soils" (MMSOELS) to estimate the ground-water and surface water risks caused
by the management of calcium sulfate sludge at the facilities in Hayden, AZ and Garfield, UT. EPA did not
model the risks caused by windblown dust because, as discussed above, the surface of the sludge dries to form
a crust that should keep windblown dust to a minimum.
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6-34 Chapter 6: Primary Copper Processing
Ground-Water Risks
Using site-specific data with respect to contaminant concentrations, sludge quantities, existing
management practices, and hydrogeologic characteristics, EPA modeled potential releases to ground water
from the calcium sulfate sludge impoundments at the Hayden and Garfield facilities. The Agency used median
contaminant concentration as inputs to the model in order to obtain a "best estimate" of the most likely risks.
EPA considered in this analysis the potential releases of arsenic, cadmium, selenium, and mercury, which are
the primary constituents of concern through the ground-water pathway based on the preceding analysis of the
sludge leachate.
The Agency's ground-water modeling results indicate that all four of these contaminants are likely
to remain bound up in the unsaturated zone well beyond the modeling time frame that was considered (200
years). Even though the sludge is generated as a slurry and discharged to impoundments along with liquids,
the liquids quickly evaporate in the extremely arid settings of these facilities. After evaporation of the slurry
water, the only force available to drive contaminants from the dried sludge to the subsurface is the infiltration
of precipitation, which occurs at a very slow rate in these areas of Arizona and Utah. Combining this factor
along with the depth to ground water at these sites and the tendency of each contaminant to bind to soil, the
Agency predicted that it would take the contaminants at least 350 years to migrate to the water table.
Therefore, the predicted risks associated with the release of these contaminants to the subsurface are
effectively zero within the 200-year modeling horizon.
Surface Water Risks
To evaluate surface water risks, EPA modeled potential releases and impacts at the facility in Hayden,
AZ, which presents by far the greatest surface water threat of the two facilities that generate the sludge (the
Hayden facility is located only 80 meters from the moderately sized Gila River, while the impoundments at
the Garfield facility are located roughly 3300 meters from the Great Salt Lake). EPA considered in this
analysis the annual loading of contaminants to the Gila River via ground-water seepage and erosion of fine
particles from the calcium sulfate sludge impoundment, conservatively assuming that the impoundment is filled
with sludge and not covered or equipped with stormwater run-off controls - even though the impoundment
is actually equipped with run-off controls. The Agency predicted the surface water concentrations of 12
constituents after they have been fully mixed in the river's flow: aluminum, antimony, arsenic, cadmium,
copper, lead, manganese, mercury, nickel, selenium, silver, and zinc. For each constituent, the Agency
compared the predicted concentrations to EPA-approved benchmarks for human health protection, drinking
water maximum contaminant levels (MCLs), freshwater ambient water quality criteria (AWQCs) for chronic
exposures, and guidelines for irrigation and livestock waters recommended by the National Academy of
Sciences.
For all but two constituents, the predicted concentrations in the Gila River were at least one order
of magnitude below the various criteria, and most constituent concentrations were more than two orders of
magnitude below the criteria. The exceptions were arsenic, the only carcinogen of potential concern, and
silver. The predicted concentration of arsenic in the river, if ingested over a lifetime, poses a cancer risk of
2X10"4 (i.e., the chance of getting cancer would be 2 in 10,000 over a 70-year lifetime). However, this arsenic
concentration is approximately an order of magnitude below the MCL. Furthermore, to the best of EPA's
knowledge, the Gila River is not currently used for drinking water within 24 km of the Hayden facility,
although it conceivably could be used in the future.
The predicted concentration of silver in the Gila River exceeded the AWQC designed to protect
aquatic organisms by a factor of almost three. Chronic exposures to this silver concentration could adversely
affect any organisms living in the Gila River.
Of the constituents that were modeled, only selenium is recognized as having the potential to
biomagnify (concentrate in the tissues of organisms higher in the food chain). Although EPA predicted
surface water concentrations of selenium that were more than two orders of magnitude below the AWQC,
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Chapter 6: Primary Copper Processing 6-35
there is a potential for selenium to biomagnify and cause adverse effects to wildlife at higher trophic levels.19
Cadmium, selenium, zinc, lead, and to a lesser extent, arsenic may bioaccumulate in the tissue of freshwater
fish that may be ingested by humans. Using assumptions about fish ingestion rates,20 the Agency estimates
that long-term ingestion of fish caught from the Gila River could pose a cancer risk of 3 x 10**. Fish ingestion
would not result in a chemical dose that exceeds a noncancer effect threshold.
EPA believes these are reasonably conservative, upper-bound estimates of the surface water risks at
the Hayden Facility. As discussed above, the impoundment at this facility is actually equipped with stormwater
run-off controls and, depending on the efficiency of these controls, the concentrations of contaminants in the
Gila River should be lower than predicted.
6.3.4 Damage Cases
EPA reviewed State and EPA regional files in an effort to document the performance of waste
management practices for slag, slag tailings, and calcium sulfate sludge from the treatment of wastewater from
primary copper processing, at the 10 active facilities and at eight inactive (at least with respect to primary
copper processing) facilities. The inactive facilities included: Cox Creek Refining in Baltimore, MD;
ASARCO in Tacoma, Washington; ASARCO in Corpus Christi, Texas; Anaconda in Anaconda, Montana;
AJO in New Cornelia, Arizona; South Wire Co. in Carrolton, Georgia; Highland Boy Smelter in Near Salt
Lake, Utah; and Midvale Slag in Midvale, Utah.
The file reviews were combined with interviews with State and EPA regional regulatory staff.
Through these case studies, EPA found no documented environmental damages attributable to slag tailings
or calcium sulfate sludge management EPA did find documented environmental damages associated with
copper slag at four facilities: ASARCO in Tacoma; ASARCO in El Paso; Anaconda in Anaconda; and
Midvale Slag in Midvale.
ASARCO, Tacoma, Washington (Commencement Bay, Puget Sound)
ASARCO's smelter is located in the Nearshore area close to Ruston. The plant, operational from
the late 1800's until March 1985, generated copper slag that has been deposited along the shoreline near the
plant and has been used as fill, riprap, and ballast material in the Tideflats area of Commencement Bay. The
slag has also been used to produce building insulation and commercial sandblasting material, which has been
used in the Nearshore/Tideflats area.21
Commencement Bay is an embayment of approximately nine square miles in southern Puget Sound,
Washington. The bay opens to Puget Sound to the northwest, with the city of Tacoma situated on the south
and southeast shores. Residential portions of northeast Tacoma and the Browns Point section of Pierce
County occupy the north shore of the bay.
From November 1983 through June 1984, the Washington Department of Ecology Water Quality
Investigation Section (WQIS) conducted a remedial investigation to characterize surface run-off from 12 log
storage and sorting facilities ("son yards") in the Tideflats area and contamination of adjacent surface water
19 The AWQC for selenium does not necessarily protect against biomagnification.
20 For the purpose of this screening-level analysis, EPA assumed that a 70-kg individual ingests 6-5 grams of fish from the Gila River
every day of the year for 70 yean. This » a typical daily fish intake averaged over a year (EPA, Risk Assessment Guidance for Superfund.
Volume I, Human Health Evaluation Manual (Pan A), EPA/540/1-89/002, December 1969).
21 Tetra Tech, Inc., 1985, Summary Report for Commencement Bay Nearsbore/Tideflats Remedial Investigation, August, 1985.
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6-36 Chapter 6: Primary Copper Processing
and sediment in the Blair and Hylebos 'Waterways. These log son yards have received ASARCO's slag as
ballast material.22123
According to the WQIS report dated February 27, 1985: "Metals concentrations were measured in
run-off from twelve log sort yards on the Tacoma tideflats and in the adjacent surface waters and sediments
of Blair and Hylebos Waterways. High concentrations of arsenic, zinc, copper, and lead were present in the
run-off from ten yards....The combined annual metals loads (pounds/year) to Commencement Bay waterways
from all twelve yards were estimated to be: arsenic, 2^00; zinc, 1,100; copper, 510; lead, 310; nickel, 66;
antimony, 50; and cadmium, 2. Because it appears surface run-off accounts for only about 40 percent of the
rainfall in these sort yards, there is a strong probability that contaminated groundwater may be a substantial
additional source of metals flux to the waterways....Peak concentrations of arsenic, zinc, and copper in surface
water and sediments in Blair and Hylebos Waterways were recorded in the vicinity of the log sort yards. EPA
acute criteria for the protection of saltwater aquatic life were exceeded for zinc and copper in Blair and
Hylebos surface waters adjacent to discharges from Murry Pacific yards #1 and #2 as well as the
Wasser/Winters yard....The use of ASARCO slag for ballast at the log son yards is, in all probability, the major
source of elevated metals concentrations seen in log sort yard run-off, nearshore surface waters, and
sediments."24
WQIS did a comparison of metals concentrations in ASARCO slag and WQIS data on log son yard
run-off, nearshore surface water, and sediment. The WQIS repon concluded that the major source of elevated
metal concentrations seen in the log son yard run-off, and adjacent surface waters and sediment, was the
ASARCO slag previously used by the yards for ballast.25
During 1986 and 1987 EPA conducted site inspections of four log son yards and one wood waste
landfill (B&L Landfill) in the Nearshore/Tideflats. The inspection included the installation of 23 monitoring
wells, and collection of 25 soil samples and 68 ground-water samples. Soil samples taken at log son yards
indicated arsenic content ranging from 5.5 to 8.2 mg/kg, copper content ranging from 3.0 to 24 mg/kg, lead
ranging from 2.7 to 10 mg/kg, and zinc ranging from 22 to 55 mg/kg. Unaltered ground-water samples from
wells installed at the log son yards contained arsenic at levels ranging from 0.011 to 0.22 mg/L, copper ranging
from 0.018 to 0.696 mg/L, lead ranging from 0.0074 to 0.300 mg/L, and zinc ranging from 0.025 to 0.865
mg/L.26
According to the EPA site inspection repon for the Nearshore/Tideflats area, of the 19 ground-water
monitoring wells installed in or around the four log son yards, ground-water samples from 15 of the 19 wells
exceeded one or more drinking water standards, maximum contaminant levels (MCLs), or freshwater and
marine acute and chronic ambient water quality criteria (WQC) identified for one or more of the four
contaminants of concern (arsenic, copper, lead, zinc).27
22 Norton, Dale, and Johnson, Art, 1985*, Washington Department of Ecology, Water Quality Investigation Section, Memo to Jim
Krull, Re: Completion Report on Water Quality Investigation Section Project for the Commencement Bay Nearshore/Tideflats Remedial
Investigation: Metals Concentrations in Water, Sediment, and Fish Tissue Samples from Hylebos Creek Drainage, August, 1983 -
September 1984, January 25.
23 Norton, Dale, and Johnson, Art, 198Sb, Washington Department of Ecology, Water Quality Investigation Section, Memo to Jim
Krull, Re: Completion Repon on Water Quality Investigation Section Project for the Commencement Bay Nearshore/Tideflats Remedial
Investigation: Assessment of Log Sort Yards as Metals Sources to Commencement Bay Waterways, November 1983 - June 1984, February
27.
24 Ibid.
"Ibjd,
26 Ecology and Environment, Inc., 1987, Site Inspection Report: Commencement Bay Nearshore/Tideflats, Tacoma, Washington, Vols.
I and II, November.
27 Ibid.
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Chapter 6: Primary Copper Processing 6-37
Anaconda Smelter Site, Anaconda, Montana
The Anaconda facility is located at the southern end of the Deer Lodge Valley, approximately 25
miles northwest of Butte. From 1884 to 1980, ore from mines near Butte, Montana was transported and
processed at various locations on the Anaconda site. In 1902, facilities were developed at the present smelter
site on the south side of Deer Lodge Valley about one-half mile east of the town of Anaconda. Ore was
mechanically concentrated, roasted, and smelted in reverberatory furnaces to produce copper matte and slag
(as a waste product). The slag was cooled and granulated with the addition of water and the resulting slurry
was transported to the waste pile through a system of flumes.28 The facility is one of four Superfund sites
in the Upper Clark Fork Basin area of southwestern Montana. Among the operable units identified for
cleanup is the slag.29
Although the facility has not operated since 1980, ore beneficiation and processing wastes, including
about 142 million cubic meters (185 million cubic yards) of tailings, about 21 million cubic meters of furnace
slags, and about 190,000 cubic meters of flue dust, are contained within an area of more than 2400 hectares
(6,000 acres) at the site.30 These wastes contain elevated concentrations of heavy metals, such as copper
(3,140 - 9,760 mg/kg), cadmium (4.4 - 44 mg/kg), arsenic (498 - 3,190 mg/kg), lead (364 - 4,310 mg/kg), and
zinc (8,380 - 36300 mg/kg).31
Anaconda's smelter slag has been used by the Montana Department of Highways for sanding roads,
some of which parallel the shore of Georgetown Lake. In a November 1982 EPA report, distributed to the
Technical Advisory Committee of the Clean Lakes Project in Anaconda, Montana, it was recommended that
use of the smelter slag for road sanding be at least partially terminated based on the consistent occurrence of
mercury in water samples that had been exposed to slag, the presence of cadmium above background levels
in lake water and downstream samples, and the fact that zinc and copper are released by slag under conditions
obtainable in the aquatic environment in Georgetown Lake. The report states that no danger to human health
existed through contamination of the Georgetown Lake ecosystem by slag or slag leachates from road sanding
operations, but that the potential existed that fish were being "negatively affected in their reproduction."32
A1983 report by the U.S. Department of Health and Human Services noted that hazards from closed
mining operations include potential airborne exposures from dust clouds containing heavy metals from tailings
ponds or slag piles. Based on findings in this study, the report recommended that public access to the
Anaconda site be terminated, that the waste slag not be used for any commercial purposes, and that further
testing should be conducted.33
Because of the results of these findings, other agencies have reached similar conclusions. In addition
to the U.S. Department of Health and Human Services, the U.S. EPA and the Montana Department of Health
and Environmental Sciences have all recommended that the Anaconda smelter slag no longer be used for road
sanding activities.34-35'36
28 Anaconda. 1985. Granulated Slag Pile, Draft, Stage I Remedial Investigation Report.
29 U.S. Environmental Protection Agency, Region VIII, 1990. Letter from C Coleman to K. McCarthy, ICF Incorporated,
Re: Anaconda Smelter. May.
30 U.S. Environmental Protection Agency and Montana Department of Health and Environmental Sciences. 1988. Clark Fork
Superfund - Master Plan.
31 Clement Associates, Inc. 1985. Letter from M.C. Lowe to M. Bishop, Region VIII EPA, Re: Response to Request by County to
Use Granulated Slag on Roads.
32 U.S. Environmental Protection Agency. 1982. Memorandum from M. Kahoe to Technical Advisory Committee Member.
33 U.S. Department of Health and Human Services. 1983. Memorandum from Chief, Superfund Implementation Group to E.
Skowronski, EPA Region 7, 8.
34 aa.
35 Camp Dresser & McKee Inc. 1985. Memorandum from J. Ericson to M. Bishop, EPA, Re: Response to County's Request to Use
Granulated Slag for Winter Road and Sanding Operations.
36 Montana Department of Health and Environmental Sciences. 1984. Letter from J J. Drynan to G. Wicks, Director, Department
of Highways, Helena, metric tons.
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6-38 Chapter 6: Primary Copper Processing
A 1985 Draft Stage I Remedial Investigation Report, prepared by Anaconda, noted that leachate
samples from the slag pile contained cadmium at less than 0.004 to 0.03 mg/L, lead at less than 0.003 to 0.025
mg/L, and copper at 0.128 to 11.6 mg/L. The maximum leachate concentrations from these samples exceeded
drinking water MCLs for cadmium (MCL = 0.01 mg/L), and copper (MCL = 1.0 mg/L). In addition, the
ambient water quality criteria (AWQC) for copper (0.012 mg/L) is exceeded by almost 1,000 times, the AWQC
for cadmium (0.0011 mg/L) is exceeded by almost 30 times, and the ambient water quality criteria for lead
(0.01 mg/L) is exceeded by 25 times.37 Although the use of Anaconda's slag for road sanding has been
terminated, the slag material continues to be sold commercially as a sand blasting material. However, a worker
at the sandblasting facility has formally complained of skin and throat irritation.38
Midvale Slag Site, Midvale, Utah
The Midvale Slag site is a parcel of land encompassing approximately 330 acres located immediately
west of the city of Midvale, which is twelve miles south of Salt Lake City, Utah. Land use within the three
mile radius of the site is primarily for agricultural, residential, and transportation purposes. The site is
bounded on the west by the Jordan River, with agricultural lands immediately across the river. Residential
areas border the north and east sides of the site. Approximately 33,700 individuals live within three miles of
the site. EPA proposed the site for the Superfund National Priority List in 1986 (see 51 FR 21099, 21106,
June 10, 1986.)
Ground water occurs beneath the site in both a shallow unconfined aquifer system, and a deep
confined aquifer system. Ground water from the shallow unconfined aquifer system is used by approximately
500 residents (for domestic use that may not include drinking) and is used to irrigate approximately 24
hectares (60 acres) of agricultural land. Water from the deep confined aquifer is used as the primary source
of water for many of the communities in the Salt Lake Valley. Normal annual precipitation at the site is
approximately 36 cm (14 inches).
Although the first smelter was constructed at the Midvale Slag site in 1871, most of the smelting
activity occurred between 1906 and 1958 when the United States Smelting, Refining, and Mining Company
owned the property. Beginning in 1905, the smelter processed copper and lead concentrates from the United
States Smelting, Refining, and Mining Company Mill, and from custom shippers. Remnants of the smelter
activity include a large slag pile, approximately 40 hectares (100 acres) in size.
In 1958, operations at the smelter ceased, and shortly thereafter the smelter facilities were dismantled.
The site was purchased in 1964 by Valley Materials Corporation (VMC), which recovers the slag material for
use as road and railroad bed construction material, and as a sandblasting abrasive for industrial and
commercial use.
A1986 hydrogeochemical site characterization study, conducted for VMC, showed that contamination
of the shallow (unconfined) aquifer has occurred. Dissolved arsenic, cadmium, and mercury were all detected
at levels exceeding MCLs.39 In discussing the cause of this contamination, the slag was not mentioned as
a source; however, given the composition of the slag, the extent of the site covered with slag, and the proximity
of the slag to other wastes, it seems likely that the slag is contributing to the contamination to some
37 Anaconda. 1985. Granulated Slag Pile, Draft, Stage I Remedial Investigation Report.
x U.S. Environmental Protection Agency, Region VIII. Letter from C. Coleman to K. McCarthy, ICF Incorporated, Re: Anaconda
Smelter. May.
39 Earthfax Engineering, 1986. Hydrogeochemical Characterization of the Valley Chemicals Corporation Site, Midvale, Utah. Prepared
for Valley Materials Corporation. August.
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Chapter 6: Primary Copper Processing 6-39
degree.40 Recent hydrogeological studies at the site indicate that there is interconnection between the deep
confined aquifer and shallow portions of the valley aquifer under the site.41
In 1987, EPA completed a "Final Preliminary Level I Endangerment Assessment" of the Midvale Slag
site. As discussed in the report, various smelter wastes have been deposited on site, including slag, dross, and
baghouse dust, and all contain high concentrations of heavy metals. According to the report, the slag contains
up to 340 ppm arsenic, 45 ppm cadmium, 2,380 ppm copper, 9,410 ppm lead, 36 ppm silver, and 58,500 ppm
zinc. As stated in the report: "None of the waste sources are adequately secured and releases have occurred
through air and groundwater pathways. In addition, direct contact with these waste sources is very likely due
to the extensive earth moving and industrial vehicle activity at the site."42
As stated in the report: "... current studies indicate that several metals are present in ground water,
air (by indirect inference), and soil in the vicinity of the Midvale Slag site at concentrations that may endanger
human health and the environment. Access to the site is currently not restricted and a commercial slag
operation exists on-site, resulting in extensive earth moving and industrial vehicle activity on site. Fine grained
waste source material may be inhaled, ingested, deposited as household dust, or deposited on nearby soils.
Contaminants from the site also appear to be leaching into the ground-water system."43
In presenting a risk and impact evaluation, the report states: "Metal contamination from the Midvale
Slag site presents a potential endangerment to human health and the environment due to actual and potential
exposure and toxicity." All residents adjacent to the Midvale Slag site, as well as on-site workers, are
potentially subjected to arsenic, cadmium, chromium, lead, and silver exposure via inhalation of contaminated
dust. Consumption of crops or garden vegetables grown in contaminated soils may also increase human
exposure to these contaminants.44 The report also notes that children from ages six to 16 may play or ride
bicycles on the waste piles, increasing the risk of ingestion.
The report concludes that "over two million tons of accumulated, unconsolidated slag waste, smelter
waste, dross, and baghouse dust at the Midvale Slag site have caused metals contamination on-site and,
probably, off-site."45
ASARCO, El Paso, Texas
ASARCO's El Paso Plant is located in El Paso, Texas, between Interstate Highway 10 and the Rio
Grande River. ASARCO's smelting plant is used for the recovery of zinc, copper, and lead, for production
of the principal products, copper anodes, lead bullion, and zinc oxide. ASARCO has operated the El Paso
facility since 1883.
Waste smelter slag has historically been deposited on-site. Many of the present structures are built
on old waste slag deposits. Slag from the zinc fuming furnace and copper reverb process is stored on-site and
removed by a contractor, who crushes it and, sells the material for railroad bedding or sandblasting abrasives.
Lead slag is being stored on-site until it becomes economically viable to recycle and refine this material for
zinc recovery.46
40 Earthfax Engineering, 1966. !*•«*«»£ Potential of Slag and Slag-Based Airblasting Abrasives at the Valley Chemicals Corporation
site, Midvale, Utah. Prepared for Valley Materials Corporation. June.
41 Camp, Dresser, & McKee, 1990. Hydrogeotogic information provided during the Sharon Steel Superfund Site Remedial Investigation
and Feasibility Study on Operating Unit 1; Ground Water. U.S. Environmental Protection Agency Administrative Record on the Sharon
Steel/Midvale Tailings site.
42 EPA Region VHI. September, 1987. Preliminary Level I Endangerment Assessment, Midvale Slag Site. Document No.: 347-ES1-
RT-FBBL, as a pan of Terformance of Remedial Response Activities at Uncontrolled Hazardous Waste Sites.
43 Ibid.
44 Ibid.
45 Ibid.
46 Engineering Science, Inc. 1984. RCRA 3012 Site Inspection Comments.
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6-40 Chapter 6: Primary Copper Processing
Waste piles have been built on slag deposits of unknown permeability. In general, the waste piles
have received smelting slag from the zinc, copper, and lead processes, fire assay crucibles, used kiln brick, iron
scrap, and pond dredgings.47
Samples from stonnwater run-off taken in 1981 and 1982 show that primary and secondary drinking
water levels were exceeded for arsenic, cadmium, chromium, copper, lead, manganese, mercury, silver, and zinc.
Samples from the southern edge of the slag deposits that were taken in July 1981, and September and
December, 1982 show ranges of total concentrations of metals as follows: arsenic, 0.84 to 11.6 mg/L; cadmium,
2.05 - 12.0 mg/L; chromium, 0.04 - 0.31 mg/L; copper, 16 - 240 mg/L; lead, 28 - 220 mg/L; manganese, 2.3 -
12.0 mg/L; mercury, 0.046 - 0.160 mg/L; and zinc, 21 - 102 mg/L. Silver was detected at 1.28 mg/L. In
addition, EP toricity criteria were exceeded for lead, cadmium, and arsenic. The Texas Department of Water
Resources concluded that ASARCO was in violation of Texas regulations prohibiting discharge of hazardous
metals to inland waters (TDWR Permanent Rules 156.19.002).48
An Industrial Solid Waste Compliance Monitoring Inspection, conducted in 1985 by the Texas
Department of Water Resources, noted that stormwaters from the slag landfills and from the plant, which has
received much slag fill, have high levels of heavy metals and have discharged into the American Canal and the
Rio Grande River.49
In 1986, a Solid Waste Compliance Monitoring Inspection Report was completed by the Texas Water
Commission. When compared to concentrations upstream and downstream of the facility, elevated
concentrations of arsenic, lead, cadmium, and copper in Rio Grande sediments near the ASARCO facility
waste slag were found. For example, lead was detected at 7.0 mg/L upstream, 62 mg/L at the ASARCO
facility, and 24 mg/L downstream.50
According to the Texas Water Commission, the primary problems at this site have evolved from
surface run-off from slag piles and unlined settling ponds. In June 1987, The TWC Superfund Unit
determined that improvements at the facility, e.g., lining the ponds and diverting surface run-off to a central
retention area for sampling before discharge, had resulted in the company achieving compliance with the Texas
Water Code.51
6.3.5 Findings Concerning the Hazards of Primary Copper Processing
Special Wastes
Copper Slag
Copper slag constituents that pose the greatest potential threat to human health and environment
include arsenic, copper, lead, molybdenum, and cadmium, although there are nine other contaminants that
exceed the conservative risk screening criteria. Cadmium and lead measured in EP leach tests exceeded the
EP toricity regulatory levels in one out of roughly 70 samples. However, when analyzed using the SPLP test,
neither of these constituents failed the EP tenacity criteria.
Based on an examination of the characteristics of each site and predictive modeling, copper slag
appears to pose a low risk at most of the active copper facilities. Almost all of these facilities are located in
areas with generally low-risk environmental and exposure characteristics (e.g., very low precipitation and net
47 U.S. Environmental Protection Agency, Region VI. No date. Surface Impoundments Site Inspection Report for Holding Pond and
Storage Facilities Site Inspection Report.
48 U.S. Environmental Protection Agency. August 27,1984. Potential Hazardous Waste Site Tentative Disposition.
49 Texas Department of Water Resources. 1985. Industrial Solid Waste Compliance Monitoring Inspection Report.
50 Texas Water Commission. April 26,1986. Solid Waste Compliance Monitoring Inspection Report.
51 U.S. Environmental Protection Agency, Region VI. June 2, 1987. Record of Communication from Christy Smith, Head, TWC
Superfund Unit to David Gonzalez, Re: ASARCO, Inc.
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Chapter 6: Primary Copper Processing 6-41
recharge, large depths to ground water, minimal use of nearby surface and ground-water resources, and great
distances to potentially exposed populations). A possible exception is the facility in White Pine, MI. Using
the conditions at White Pine as a conservative model, the Agency predicts low risks associated with potential
releases of slag contaminants to ground water and air, including cancer risks that are below IxlO"6 and
contaminant concentrations at possible exposure points that are orders of magnitude below hazard criteria.
Erosion of contaminants into nearby surface waters, however, could cause greater impacts. The Agency
predicts that, if not controlled, erosion from a slag pile could result in annual average surface water
concentrations of lead, iron, and molybdenum that exceed MCLs or irrigation guidelines by a narrow margin
(a factor of 2 or less), as well as copper concentrations that exceed the AWQC by as much as a factor of 65.
Contamination of this magnitude, however, should not actually occur at the White Pine Facility because the
slag dump at that site is equipped with stormwater run-on/run-off controls. Similarly, significant surface water
contamination is not expected at the other sites because the nearest surface waters are farther away and have
a greater assimilative capacity than the conservative conditions that were modeled.
The general lack of documented cases of damage caused by copper slag at the active copper facilities
confirms that the slag at these facilities often poses a low risk. The only damage case for an active site
involved storm water run-off from slag piles at the El Paso facility and subsequent surface water
contamination, as predicted to be possible by the Agency's modeling. The El Paso facility has since installed
a run-off retention system. The other damage cases are for inactive facilities and demonstrate the potential
for damage under mismanagement scenarios that generally do not represent the industry norm.
Copper Slag Tailings
Compared with the other copper wastes, copper slag tailings contain a smaller number of
contaminants in generally lower concentrations. The greatest potential for hazard appears to be associated
with the tailings' arsenic concentrations. Based on professional judgment and available sampling results, EPA
believes that the tailings do not exhibit any of the characteristics of a hazardous waste.
Based on the Agency's review of existing management practices and release/exposure conditions, as
well as the lack of documented cases of damage caused by copper slag tailings, the overall hazard associated
with the tailings appears to be low. Although the tailings are generated as a slurry and co-managed with
liquids that could serve as a leaching medium, the contaminant concentrations in the leachate are generally
low. Furthermore, ground water at the three facilities that actively generate and manage the tailings is either
very deep (and thus somewhat protected) or not used within a mile. It is possible, however, that the ground
water could be used sometime in the future. Except for the White Pine facility, where there is a moderate
potential for tailings contaminants to migrate into surface water, the potential for the tailings to cause
significant surface water contamination appears very remote. Airborne dusting from the tailings piles can and
does occasionally occur. Windblown dust from the piles should be studied further and, if needed, controlled
to prevent significant inhalation exposures to arsenic and chromium.
Calcium Sulfate Sludge
Although calcium sulfate sludge contains as many as 12 contaminants that could pose a risk under
worst-case exposure conditions, the constituents that pose the greatest potential threat to human health and
the environment are arsenic, cadmium, lead, and selenium. Concentrations of arsenic and selenium in the
sludge leachate, as measured using the EP leach test, exceeded the EP toxicity regulatory levels in seven out
of seven samples, while cadmium exceeded the regulatory level in six of seven samples. However, using the
SPLP test, no contaminants exceeded the EP toxicity regulatory levels.
Based on a review of existing management practices and facility settings, as well as predictive modeling
results, EPA believes that the hazards associated with calcium sulfate sludge are generally low at the two
facilities where it is currently generated. Both facilities that actively generate and manage the sludge are
located in very arid locations (Hayden, AZ and Garfield, UT) where there is very little precipitation and
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6-42 Chapter 6: Primary Copper Processing
recharge to ground water. Even the liquids used to slurry the sludge into the impoundments are expected to
quickly evaporate, rather than seep into the ground. Considering this lack of water to cany sludge
contaminants to the subsurface, along with the depths to ground water and the tendency of the sludge
contaminants to bind to soil, EPA predicts that it would take more than 200 years for contaminants to migrate
from the sludge into ground water. However, there does appear to be a slight potential for surface water
contamination caused by sludge management practices at one of the sites. If the impoundment at Hayden is
conservatively assumed to be filled with sludge and not equipped with a cover or run-off control system, the
Agency predicts that erosion from the impoundment could cause arsenic and silver concentrations in the
nearby Gila River that exceed health and ecological protection criteria. However, because the impoundment
at Hayden is in fact equipped with run-off controls, surface water contamination of this magnitude is not
actually expected. The potential for significant releases of windblown dust from the sludge appears very
remote, because the surface of the sludge dries to form a crust that is resistant to wind erosion.
No cases of documented damage caused by the sludge were discovered by EPA. This finding supports
the conclusion that as currently managed the sludge poses a generally low hazard.
The intrinsic hazard of the waste, however, is high. Several other primary copper facilities may
generate the sludge in the future, especially if the waste remains excluded from RCRA Subtitle C regulations.
As discussed above with respect to slag and slag tailings, the environmental settings of some of these other
facilities is such that risks associated with calcium sulfate sludge generated at these facilities could be higher
than at the two facilities where it is currently generated, assuming that the additional facilities used
management practices similar to those currently in use. Similarly, off-site use or disposal could result in higher
risks than those predicted for the facilities where the waste is currently generated.
6.4 Existing Federal and State Waste Management Controls
6.4.1 Federal Regulation
Under the Clean Witer Act, EPA has the responsibility for setting "effluent limitations," based on
the performance capability of treatment technologies. These "technology based limitations," which provide the
basis for minimum requirements of NPDES permits, must be established for various classes of industrial
discharges, which include a number of ore and mineral processing categories.
Permits for mineral processing facilities may require compliance with effluent guidelines based on best
practicable control technology currently available (BPT) or best available technology economically achievable
(BAT). BPT and BAT requirements for primary copper smelting specify that there shall be no discharge of
process wastewater pollutants to navigable waters (40 CFR 421.43 and 421.44).52
A number of States with primary copper smelter facilities do not have EPA-approved NPDES
programs. In New Mexico, Region VI personnel have stated that existing Federal guidelines are applied for
discharges from primary copper smelters. However, the Region may adopt State water quality criteria or any
other standards that are more stringent than Federal guidelines as required by Sections 402 and 510 of the
CWA. Similarly, the State of Arizona has no approved NPDES program; therefore, Federal requirements
would be applicable. Region DC may, however, adopt State water quality standards more stringent than
Federal guidelines.
Limitations on air emissions, National Emission Standard for Hazardous Air Pollutants (NESHAP),
have been established by EPA under the Clean Air Act (40 CFR 61.12) for emissions of inorganic arsenic from
primary copper smelter convenors. The standards require operators to meet certain design, equipment, work
practice, and operational requirements in order to achieve emission reductions.
52 This limitation includes a provision, however, that an impoundment designed to contain the 10-year, 24-hour rainfall event may
discharge that volume of process wastewater which is equivalent to the volume of precipitation that falls within the impoundment in excess
of that attributable to the 10-year, 24-hour rainfall event, when such event occurs.
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Chapter 6: Primary Copper Processing 6-43
The Cyprus Miami Mining Corporation Copper Smelter in Claypool, Arizona is located on Federal
land, in a National Forest This facility is subject to the regulations set forth by the U.S. Forest Service.
National Forest System lands are regulated by the U.S. Department of Agriculture's Forest Service. The
regulations governing the use of the surface of National Forest Service lands (36 CFR 228 Subpart A) are
intended to "minimize adverse environmental impacts...." The regulations require that operators file a "notice
of intent to operate." If deemed necessary, the operator may be required to submit a proposed plan of
operations in order to ensure minimal adverse environmental impact
The National Environmental Policy Act (NEPA) may also be applicable to this facility. NEPA may
require that an Environmental Impact Statement (EIS), which establishes the framework by which EPA and
the Council on Environmental Quality may impose environmental protection requirements (40 CFR Parts
1500-1508), be prepared for any ore processing activities on Federal lands.
6.4.2 State Regulation
One or more of the three special wastes from primary copper processing (slag, slag tailings, and
calcium sulfate sludge) are generated at 10 facilities located in five states, including Arizona (three facilities),
Michigan (one facility), New Mexico (two facilities), Texas (three facilities), and Utah (one facility). All five
of these states exempt the special primary copper processing wastes generated by the facilities from regulation
as hazardous waste. Of these five states, only Michigan was not selected for detailed study for the purposes
of this report (see Chapter 2 for a discussion of the methodology used for selecting study states). Copper slag
is generated at facilities located in all four of the study states, while slag tailings and calcium sulfate sludge
are generated at facilities located in Arizona and Utah only. Based on the location of the nine facilities in
the four study states, and the waste streams that those facilities generate, the state regulation of primary
copper processing wastes is of principal interest in the States of Arizona, Utah, and Texas.
The three primary copper processing facilities in Arizona generate one or more of this sector's three
special wastes. Because Arizona's solid waste regulations classify mineral processing wastes as industrial solid
wastes, all three waste streams are subject to these solid waste regulations. According to state officials,
however, the state's emphasis in implementing its regulations has been on municipal solid waste landfills; the
state has not imposed regulations specifically addressing wastes from mining or mineral processing operations.
Arizona also has in place a ground-water discharge permitting program that specifically lists surface
impoundments, including holding impoundments, storage settling impoundments, treatment or disposal pits,
ponds, lagoons, and mine tailings piles or ponds, as discharging units that must be permitted. Arizona has
focused its efforts to date, however, on permitting new facilities. The single facility generating calcium sulfate
sludge, thus, does not have a ground-water discharge permit, while the other two facilities have permits for
only selected mining and mineral processing waste units. Finally, Arizona regulations adopt federal new and
existing source performance standards for primary copper smelting operations, including fugitive dust
limitation conditions for tailings piles and ponds.
Utah is the only other state in which all three special wastes from primary copper processing are
generated. A single copper processing facility in Utah generates all of these wastes. Utah excludes all of these
processing wastes from both its hazardous waste and solid waste regulations. The state does have an approved
NPDES program, however, and imposes discharge permit requirements on the tailings impoundment used for
disposing slag tailings and other wastes at its one facility. The state also recently enacted new ground-water
protection legislation, though it has not yet issued any ground-water discharge permits. Finally, Utah's air
regulations specifically regulate sulfur dioxide and visible compounds air emissions at the facility, but address
fugitive dust emissions only under general requirements for tailings ponds and piles.
The two facilities in New Mexico, three facilities in Texas, and one facility in Michigan generate
copper slag only, though two of the Texas facilities do not generate smelter slag and recycle their convener
and anode slag. New Mexico specifically excludes mineral processing wastes from its solid waste regulations.
Both EPA and state effluent discharge limitations apply at both New Mexico facilities. Moreover, both
facilities have discharge plans for the protection of ground water, though neither of the facilities' plans address
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6-44 Chapter 6: Primary Copper Processing
slag disposal. Similarly, New Mexico's air regulations require permits for all sources of air contaminants and
specify limitations for a variety of mineral processing operations, though copper processing is not mentioned
specifically. In contrast to New Mexico, Texas addresses copper slag under its solid waste regulations. Only
one of the three facilities in the state, ASARCO's El Paso facility, is subject to the requirements of these
regulations and other environmental regulations, however. The state has not addressed the other two facilities
because those facilities reuse their slag. Moreover, Texas has required only that the ASARCO plant notify
the state of its waste management activities and provide basic waste characterization information; the state has
not required a solid waste disposal permit at the facility because ASARCO disposes of its slag on property
that is both within 50 miles of the facility and is controlled by the company. Texas surface and ground-water
protection criteria and fugitive dust emission controls apply at the ASARCO facility only. Texas has not
imposed fugitive dust controls at the ASARCO facility, but has actively implemented its water protection
regulations and is currently administering an enforcement order addressing un-permitted releases to the Rio
Grande River. Finally, although Michigan was not studied in detail for this report, review of the state's
regulations suggest that the copper slag generated at the White Pine facility is exempt from solid waste
regulations because it is reused.
In summary, all of the states with primary copper processing facilities exclude the special processing
wastes generated at these facilities from their hazardous waste regulations. The states vary in the application
of solid waste regulations to these wastes. Both Utah and New Mexico specifically exempt mineral processing
wastes from solid waste regulation, while Michigan's regulations contain exemptions for slag that is reused or
reprocessed. Although Arizona and Texas classify primary copper processing wastes as solid wastes, neither
state has actively regulated the management of these wastes under such authority. In contrast, all of the states
appear to address some or all of the copper processing wastes generated within their borders to some extent
under state surface water discharge permitting programs, while Arizona and New Mexico have ground-water
discharge permit programs and Utah recently enacted ground-water protection legislation that will require
permits. Finally, although all of the states appear to have general fugitive dust emission control requirements
that could apply to copper processing wastes, the extent to which those requirements are being applied is not
clear.
6.5 Waste Management Alternatives and Potential Utilization
6.5.1 Waste Management Alternatives
Waste management alternatives, as discussed here, include both waste disposal alternatives (e.g.,
landfills and waste piles) and methods of minimizing the amount of waste generated. Waste minimization
alternatives include source reduction or recycling that results in either the reduction of total volume or toxicity
of the waste. Source reduction is a reduction of waste generation at the source, usually within a process, that
can include treatment processes, process modifications, feedstock (raw material) substitution, housekeeping
and management practices, and increases in efficiency of machinery and equipment. Source reduction includes
any activity that reduces the amount of waste that exits a process. Recycling refers to the use or reuse of a
waste as an effective substitute for a commercial product, or as an ingredient or feedstock in an industrial
process.
Opportunities for waste minimization through raw materials substitutions are limited in general by
the characteristics of the ores that are processed. Selection of source ores, improved beneficiation techniques,
or improvements in smelting technology, however, in some cases may lead to reduced slag volumes. Other
source reduction opportunities may involve process modifications that increase the efficiency of metal recovery
during the smelting operation.
The following discussion describes opportunities for recycling copper smelter slag that are practiced
in the U.S. and miscellaneous potential waste minimization practices for all three special wastes generated in
primary copper processing.
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Chapter 6: Primary Copper Processing 6-45
Recycling Copper Slag
The primary purpose of recycling copper slag is to recover additional copper from the slag. There
are six types of primary copper slag generated in the U.S.: converter, anode, reverberatory furnace, electric
furnace, flash furnace, and continuous smelter slags. Opportunities for recycling slag exist primarily for the
four types of smelter slag because most, if not all, of the converter and anode furnace slag generated at
primary copper processing facilities in the U.S. already is recycled to the process -- anode furnace slag to the
converter and converter slag to the smelter. There are three primary methods of recycling copper smelter slag
used at U.S. facilities. The method used depends upon the type of smelting furnace at the facility.
Description
Recycling of reverberatory furnace slag involves crushing and screening, and a subsequent separation
of the minerals in the slag by froth flotation in a concentrator. In this process, the copper is caused to float
to the surface with the addition of chemicals called "floaters," and is removed in a foam of air bubbles. Other
minerals sink to the bottom, are carried out in the slurry, and are disposed of in tailings ponds. The primary
residuals from this process are wastewater (about 50 to 230 metric tons per metric ton of concentrate) and
the tailings (about 25 to 50 metric tons per ton of concentrate.)
Electric furnace slag has a lower copper content than reverberatory furnace slag, making it less
amenable to recycling using a concentrator. In fact, electric furnace treatment is one method of recycling slag,
as discussed below.
Flash furnace and continuous (Noranda) smelter slags are relatively high in copper content. This
copper may be reclaimed by electric furnace slag treatment or by slow cooling, crushing, and flotation. Coke
is used in an electric furnace to reduce sulfates and metallic copper and reconstitute the copper as a sulfide.
The molten copper matte may then be recycled to a converter to produce copper metal. In the flotation
process, the molten slag is cooled slowly, and copper forms as either small particles of metallic copper or
crystals of copper-iron sulfide. These particles are held in a matrix of primarily iron silicate. The slag is
reclaimed, crushed, and sent to the concentrator. The concentrate is then returned to the smelting
process.53*54
Current and Potential Use
Of the three U.S. facilities operating reverberatory furnaces in 1988, one has classified its production
statistics as confidential. The two other facilities are the Copper Range Company in White Pine, Michigan,
and the Magma Copper Company in San Manuel, Arizona. As noted in Section 6.2.3, the Copper Range
facility generated and stored 165,000 metric tons of reverberatory furnace slag in 1988. The Copper Range
Company's slag pile has accumulated 1,360,000 metric tons of slag, and the facility retrieved 212,000 metric
tons of slag from the pile for recycling to the concentrator in 1988.55 The Magma facility also added 309,000
metric tons of reverberatory furnace slag in an on-site slag pile in 1988, but "mined* and recycled 996,000
metric tons of reverberatory furnace slag from the pile.56
*' PEDCo Environmental, Inc., Industrial Process Profiles for Environmental Use. O^pter 29: PP""TV Copper Industry. EPA-
600/2-80-170, Environmental Protection Technology Series, Industrial Environmental Research Laboratory, ORD, U.S. Environmental
Protection Agency, July 1980, p. 49.
M White, Lane, "Copper Recovery from Flash Smelter Slags: Outotoimpu Upgrades Sorting of Slags and Flotation of Copper,"
Engineering and Mining Journal. November 1983, pp. 77-81.
55 Copper Range Company, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing
Facilities," U.S. EPA.
54 Magma Copper Company, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing
Facilities," U.S. EPA.
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6-46 Chapter 6: Primary Copper Processing
Electric furnaces were used by two facilities in 1988: the Cyprus Miami Mining Corporation in
Claypool, Arizona and the Phelps Dodge Mining Company in Playas, New Mexico. The Cyprus facility
generated 310,000 metric tons of electric furnace slag in 1988 and disposed 100 percent of it in a tailings pond.
O-prus did not recycle any slag in 1988.57 The Phelps Dodge facility operated an electric furnace to process
the slag from its flash furnace operations. Its electric furnace generated 336,000 metric tons of slag in 1988.
All of the electric furnace slag was sent to a slag pile for disposal and no slag was recycled.58
Production statistics for three of the four U.S. facilities employing flash furnaces are non-confidential.
The Phelps Dodge Mining Company facility in Playas, New Mexico, the Chino Mines Company (Phelps
Dodge) facility in Hurley, New Mexico, and the Magma Copper Company facility in San Manuel, Arizona all
operated flash furnaces in 1988. As noted above, the Phelps Dodge facility in Playas sent all of its flash
furnace slag to an electric furnace for processing.59 The Chino/Phelps Dodge facility in Hurley generated
363,000 metric tons of slag from its INCO flash furnace in 1988 and recycled none.60 The Magma facility
replaced its reverberatory furnaces with a single flash furnace in 1988. This flash furnace generated 190,000
metric tons of slag in 1988. Magma reportedly recycles all of its flash furnace slag to the ore concentrator.61
Finally, the Kennecott Copper Company in Garfield, Utah generated 395,000 metric tons of slag from
its continuous Noranda process. This facility reported recycling all of the slag it generated to the slag
concentrator.62
The two copper smelting facilities with confidential production statistics are ASARCO's facilities in
El Paso, Texas, and Hayden, Arizona. The El Paso facility temporarily stores its slag in a slag pile and sells
it to an on-site third party. The material is then used for railroad fill, ballast, and blasting abrasive.63 The
Hayden facility disposes of slag in an on-site slag pile and reprocesses a portion to recover the copper
content.64
Most facilities operating flash furnaces or continuous smelters recycle their smelter slag to the
process. Recycling of reverberatory and electric furnace slags is not as common. There may be potential for
increasing the quantity of copper smelter slag that is recycled, but it is not clear that such an increase would
be economically feasible or that it would substantially affect the volume or composition of the slag generated.
Factors Relevant to Regulatory Status
The specific effects of slag recycling on volume and composition of copper slag are uncertain.
Recycling slags to a concentrator reduces volume and copper content of the slag, but creates slag tailings and
57 Cyprus Miami Mining Corporation, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing
Facilities," U.S. EPA.
58 Phelps Dodge Mining Company, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing
Facilities," US. EPA.
59 Phelps Dodge Mining Company, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing
Facilities," U.S. EPA.
<° Chino Mines Company, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing Facilities,"
U.S.EPA,
41 Magma Copper Company, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing
Facilities," US. EPA.
62 Kennecott Copper Company, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing
Facilities," U.S. EPA.
0 ASARCO Incorporated-EI Paso Plant, 1989. Company Response to the "National Survey of Solid Wastes from Mineral
Processing Facilities," U.S. EPA.
44 ASARCO Incorporated-Hayden Plant, 1989. Company Response to the "National Survey of Solid Wastes from Mineral
Processing Facilities," U.S. EPA.
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Chapter 6: Primary Copper Processing 6-47
associated wastewater. Electric furnace treatment of flash or continuous smelter slag generates a slag with a
similar content as reverberatory furnace slag.65
Feasibility
It is technically feasible to increase slag recycling at facilities that do not currently recycle 100 percent
of their smelter slag, but it is not certain that more recycling would be profitable. The primary factor
influencing a facility's decision to recycle smelter slag is the concentration of copper in the slag. Slags with
low copper content, such as the electric furnace slags, are likely to be disposed instead of recycled due to the
increased costs associated with recycling and the minimal benefits (i.e., small quantities of copper recovered).
Miscellaneous Waste Minimization Practices
Some research has been conducted on removing secondary elements from copper slag. The methods
researched are worth noting as potential waste minimization practices.
Copper and Secondary Metals Recovery from Converter Slag
Researchers in India have found that copper convener slag with a magnetite content of approximately
8 percent and a FeO/SiO2 ratio of about 1.2 could be leached at high temperatures with dilute sulfuric acid
to recover most of the copper and about 90 percent of the nickel and cobalt. Slags with a higher magnetite
content (15-20 percent) and a greater FeO/SiO2 ratio (1.3) only allowed 40-60 percent recovery of the
secondary metals. Slow-cooling this slag, however, enhanced recovery of contained nickel and cobalt to 90
percent.66
Iron Recovery and Glass Fiber Reduction from Slag
Researchers from UCLA, found that copper slag from ASARCO's Hayden, Arizona facility could
be convened into glass fiber and that iron from the slag could be recovered. The researchers melted down
a mixture of 90 percent copper slag and 10 percent CaCO3 in a Harper globar electric heating furnace using
graphite and coal powder as reductants. On remelting, the copper slag usually corrodes oxide refractories
because of the iron in the slag, but the addition of coal or graphite to the batch lowered the slag's melting
temperature and actually reduced the refractory corrosion. Iron was recovered from the slag by the reduction
of the oxide through the ferrous state to the metallic state. Glass was then cast and glass fibers were drawn
from the melt.67
Minimization of Slag Tailings and Calcium SuHate Sludge
EPA did not find any information in the literature reviewed concerning minimisation of copper slag
tailings or calcium sulfate sludge generated by primary copper processing facilities. Copper slag tailings are
generated when copper slag is recycled to the concentrator, therefore, the copper content of the tailings could
potentially be reduced if a more effective method of concentration were developed. The quantity and
composition of both slag tailings and calcium sulfate sludge could be altered if a feasible method of recovering
metals (e.g., lead, zinc) were devised for these two special wastes.
45 PEOCo Environmental, Inc., gj>. tit, p. 68.
** Das, R.P, S. Anand, K. Sarveswara Rao, and P.K. Jena, 1987, "Leaching Behavior of Copper Converter Slag Obtained Under
Different Cooling Conditions," Trans. Institution of Mining and Metallurgy (Section C Mineral Process. Extr. Metallurgy^. Vol. 96,
September, p. C161.
67 Chung, C.H., T. Minzuao, and J.D. Mackenzie, 1978, "Iron Recovery and Glass Fiber Production from Copper Slag,"
Proceedings of the Sixth Mineral Waste Utilization Symposium. Chicago, IL, May 2-3, pp. 145-147.
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6-48 Chapter 6: Primary Copper Processing
Disposal Alternatives
None of the primary copper processing facilities send their special wastes off-site for disposal. While
it is conceivable that some, or even all, of the copper processors could do so, the cost of transporting large
volumes of copper slag, slag tailings, or calcium sulfate sludge and the rising cost of commercial landfill
capacity make it unlikely that copper processors would utilize off-site disposal capacity if on-site capacity is
available and the regulatory environment does not change. Situations that could increase the likelihood of
off-site disposal are the classification of one or more of the special wastes as hazardous wastes, a limited
amount of capacity for on-site disposal, and smaller volumes of special wastes generated.
6.5.2 Utilization
Copper slags historically have been utilized in a variety of ways. Though most copper processing
facilities currently recycle or dispose of their slag, there are numerous opportunities for utilization. The
application that could potentially use the largest quantities of copper slag is use as a highway construction
aggregate. Copper slag tailings have also been utilized for construction purposes in the past, but all facilities
currently generating tailings dispose of them. The following section analyzes the potential, as identified in the
literature, for use of copper slag in highway construction and various other capacities and discusses past uses
of copper slag tailings.
Utilization as a Highway Construction Aggregate
Description
Copper slag has been used experimentally in bituminous wearing surfaces (asphalt) and as a seal coat
aggregate in highway construction. Copper slag is a hard, dense material which is either granulated (water
cooled) or air cooled. Granulated slags generally range from -8 mesh to +100 mesh in diameter and are
considered unsuitable for highway construction because of their resistance to compaction. Air cooled slags,
which are the most usable as an aggregate, can range in size from +4 mesh to chunks that measure several
inches in diameter. Copper slags, particularly air cooled slags, may require additional crushing and/or
screening to achieve uniform sizes for particular applications.68
Current and Potential Use
In the past, copper slag has been used as an aggregate in asphalt and seal coats in Arizona and Utah,
states which are among the top generators of copper slag. When used as an aggregate in asphalt, the copper
slag performed well and was shown to have desirable anti-skid and wear resistant properties, but these
pavements have a high cost associated with them due to the heavy weight (and associated transportation costs)
of the aggregate. Therefore, the Utah Department of Highways concluded that the most economical use of
copper slag is as a seal coat aggregate. One problem associated with surface mixtures incorporating copper
slag is that the aggregate particles have a tendency to become dislodged by traffic, nosing the possibility of
damaging windshields.69
The Testing and Research Division of the Michigan State Highway and Transportation Commission
investigated copper reverberatory slag from the White Pine smelter in Michigan for its suitability as an
aggregate in highway construction. A number of evaluative tests were performed and the material was found
68 Collins, RJ. and R.H. Miller, 1976, op.cit.. pp. 111-112,170.
* Ibid., pp. 114,166,170.
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Chapter 6: Primary Copper Processing 6-49
to be suitable as aggregate for all types of highway construction with the exception of aggregate for portland
cement concrete.70
Access to Markets
It is important that a waste being used as an aggregate be located as close as possible to its market
in order to keep transportation costs low. Wastes located within 50 to 100 miles of major metropolitan areas
or aggregate shortage areas are considered as being near potential markets.71 The Cyprus facility in
Claypool, Arizona is located 70 miles from Phoenix, Arizona and the Magma facility located in San Manuel,
Arizona is located 30 miles from Tucson, Arizona. Also, there is an aggregate shortage located in Northeast
Arizona, Southeast Utah, and Northwest New Mexico in which the copper slag from the Arizona, Utah, and
New Mexico facilities could be utilized. The Copper Range facility in White Pine, Michigan does not foresee
an opportunity for utilization of its slag because of the distance from the facility to potential markets for the
slag and high transportation costs, especially since there is no railhead located at the facility.
Feasibility
The major factor in determining the technical feasibility of using copper slag as an aggregate for
highway construction is the mechanical properties of the slag. The economic feasibility of using copper slag
as an aggregate will depend on the selling price of the slag and retrieval, processing, and transportation costs
associated with a particular use in a particular area.
Miscellaneous Uses
Several examples of copper slag and copper slag tailings utilization are cited in the literature, but very
few details are provided other than the fact that it has been utilized in some capacity. Given the limited
availability of information, a brief discussion of these miscellaneous utilizations is provided below.
Other Construction Materials
Studies have indicated that copper slag has potential use as portland cement replacement in concrete.
Mortars incorporating air cooled or quenched slag ground to 5000 cm2/g exhibit compressive strengths that
suggest the possibility of their use for structural concrete, but the costs associated with grinding might not
justify this use.72 Also, copper slag can be used as a source of iron in the manufacturing of portland
cement,73 (as distinct from use as aggregate in portland cement concrete).
There are a number of other uses of copper slag in construction materials. Granulated copper slag
was used during the reconstruction of a portion of the New Jersey Turnpike as an embankment material.74
Copper slag has also been used for road cindering, and as granules for roof shingles. The Copper Range
Company in Michigan has used a very small portion (less than 1 percent) of its copper slag locally for
driveways, as pipe bedding, and in road beds, when mixed with a sufficient quantity of road rock. Copper slag
70 Collins, RJ. and RJi. Miller, 1977, Availability of Mining Wastes and Their Potential for Use as Highway Material - Executive
Summary. FHWA-RD-78-28, prepared for Federal Highway Administration, September, p. 21.
71 Ibid., p. 239.
72 Douglas, Esther and Paul R. Mainwaring, 1985, "Hydntion and Pozzolanic Activity of Nonferrous Slags," American Ceramic
Society Bulletin. Vol. 64, No. 5, p. 706.
73 Collins, Robert J., 1978, "Construction Industry Efforts to Utilize Mining and Metallurgical Wastes," Proceeding of the Sixth
Mineral Waste Utilization Symposium. Chicago, IL, May 2-3, p. 141.
74 Ibid.
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6-50 Chapter 6: Primary Copper Processing
has been found to have very good drainage characteristics and would be well suited for drainfield
construction.75
Road or Railroad Ballast
Sized copper slag is an excellent material for use as road or railroad ballast because of its high natural
angle of repose and its ability to maintain slopes. For example, copper slag from the Southwest was used in
construction of a large portion of the Southern Pacific roadbed from New Orleans to San Francisco.76
Mineral Wool Insulation
The Copper Range Company in White Pine, Michigan shipped 38,486 metric tons of copper slag
between November 1976 and December 1977 to mineral wool manufacturers. In mineral wool manufacturing,
sized copper slag is mixed with other materials to adjust the overall composition of feed to the furnace. The
slag mixture is melted with coke in a cupola furnace, and the molten stream from the furnace is spun into a
mineral wool.77 Copper slag was used in mineral wool production extensively in the past, but has largely
been replaced as an input material by steel and iron slags due to the air pollution concerns associated with
arsenic and hydrogen sulfide residuals in the copper slag.78
Application as an Abradant
Granulated copper slag is used as an abradant in abrasive machining. Other potential uses of copper
slag grains are as grit in abrasive blasting, in abrasive tools bonded with low melting ceramic binders, in elastic
polyurethane bonded abrasive tools, and in abrasive compounds. It has been discovered that heat treatment
enhances the strength of copper slag grains, consequently increasing its potential use in abradants.79
Utilization of Copper Slag Tailings
Copper slag tailings and ore tailings may be co-generated by a concentrator or mixed for disposal if
there are separate slag and ore concentrators at the facility. References in the literature to the use of copper
tailings do not clearly state whether the past uses of tailings applied to only ore tailings, only slag tailings, or
both. Presumably, the mechanical properties of both types of tailings will be similar and they could be used
individually or in combination for each application.
Copper tailings were used in both Michigan and Utah as embankment material and in bituminous
mixtures. In Michigan, an unspecified quantity was used as embankment and sub-base material for U.S. Route
41 and for other projects as an aggregate in bituminous mixes and as anti-skid material. Between 1972 and
1976, over 5 million metric tons of classified copper tailings from the Kennecott facility were used in the
construction of highway embankments throughout the State. Kennecott constructed a separation facility in
1972 to classify and deposit coarser tailing products which are suitable for use in highway embankments. The
largest use of the tailings was 3 million metric tons in the construction of 9.6 kilometers of embankment for
75 Soyder, Houston L., 1990, Director of Safety and Environmental Attain, Copper Range Company, White Pine, Michigan,
personal communication, April 9.
76 Bingham, Edward R., 1968, "Waste Utilization in the Copper Industry," Proceedines of the First Mineral Waste Utilization
Symposium. Chicago, IL, March 27-28, p. 75.
77 Oarkson, J.F., R.H. Johnson, E. Siegal, and W.M. Vlasafc, 1978, "Utilization of Smelter Slags at White Pine Copper Division,"
Proceedings of the Sixth Mineral Waste Utilisation Symposium. Chicago, IL, May 2-3, p. 99.
78 Brayman, Bill, Vice President, Rockwool Manufacturing Company, Leeds, Alabama, personal communication, April 11,1990.
79 Wozniak, K., 1988, "Cutting Property Assessment of Copper Slag," Metal Finishing. November, p. 37.
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Chapter 6: Primary Copper Processing 6-51
Interstate 215. Utah also used tailings as a mineral filler in bituminous mixtures, but the Department of
Highways found that this application was not as successful as use in embankment construction.80
Conclusions
Although copper slag and slag tailings are commonly either recycled or disposed of in stacks or ponds,
there does appear to be some potential for utilization of these materials, particularly in construction
applications. There is no indication in the literature reviewed that there are any potential means of utilizing
calcium sulfate sludge. If the special wastes were used as construction materials there might, under some
circumstances, be concerns regarding potential contaminant release and subsequent environmental degradation.
It is unclear whether such non-disposal management alternatives represent a net reduction in the risks posed
by these materials as compared to current practices. One major obstacle to more widespread utilization of
the special wastes is social acceptability. While utilization of copper slag and slag tailings is likely to be more
acceptable to the public than utilization of some of the other special wastes (e.g., lead slag), some opposition
to their use in construction materials or in other capacities may be expected.
6.6 Cost and Economic Impacts
Section 8002(p) of RCRA directs EPA to examine the costs of alternative practices for the
management of the special wastes considered in this report. EPA has responded to this requirement by
evaluating the operational changes that would be implied by compliance with three different regulatory
scenarios, as described in Chapter 2. In reviewing and evaluating the Agency's estimates of the cost and
economic impacts associated with these changes, it is important to remember what the regulatory scenarios
imply, and what assumptions have been made in conducting the analysis.
The focus of the Subtitle C compliance scenario is on the costs of constructing and operating
hazardous waste land disposal units. Other important aspects of the Subtitle C system (e.g., corrective action)
have not been explicitly factored into the cost analysis. Therefore, differences between the costs estimated for
Subtitle C compliance and those under other scenarios (particularly Subtitle C-Minus) are less than they might
be under an alternative set of conditions (e.g., if most affected facilities were not already subject to Subtitle C).
The Subtitle C-Minus scenario represents, as discussed above in Chapter 2, the minimum requirements that
would apply to any of the special wastes that are ultimately regulated as hazardous wastes; this scenario does
not reflect any actual determinations or preliminary judgments concerning the specific requirements that would
apply to any such wastes. Further, the Subtitle D-Plus scenario represents one of many possible approaches
to a Subtitle D program for special mineral processing wastes, and has been included in this report only for
illustrative purposes. The cost estimates provided below for the three scenarios considered in this report must
be interpreted accordingly.
In accordance with the spirit of RCRA §8002(p), EPA has focused its analysis on impacts on the firms
and facilities generating the special wastes, rather than on net impacts to society in the aggregate. Therefore,
the cost analysis has been conducted on an after-tax basis, using a discount rate based on a previously
developed estimate of the weighted average cost of capital to U.S. industrial firms (9.49 percent), as discussed
in Chapter 2. Waste generation rate estimates (which are directly proportional to costs) for the period of
analysis (the present through 1995) have been developed in consultation with the U.S Bureau of Mines.
In this section, EPA first outlines the way in which it has identified and evaluated the waste
management practices that would be employed under different regulatory scenarios by the primary copper
facilities generating the three special wastes. Next, the Agency discusses the cost implications of requiring
these changes to existing waste management practices. The last part of this section of the chapter estimates
and discusses the ultimate impacts of the increased waste management costs faced by the affected facilities.
80 Collins, RJ. and R.H. Miller, 1976, O£. at., pp. 150-151,176,18Z
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6-52 Chapter 6: Primary Copper Processing
6.6.1 Regulatory Scenarios and Required Management Practices
Based upon the information presented above, EPA believes that copper slag and copper calcium
sulfate sludge may be EP toxic at some facilities. Accordingly, the Agency has estimated the costs associated
with regulation under Subtitle C of RCRA, as well as with two somewhat less stringent regulatory scenarios,
referred to here as "Subtitle C-Minus" and "Subtitle D-Plus," as previously introduced in Chapter 2, and as
described in specific detail below.
EPA has adopted a conservative approach in conducting its cost analysis for the wastes generated by
the primary copper industry. For the two wastes that pose potential risk, the Agency has assumed that these
materials would exhibit EP toxicity at all facilities unless actual sampling and analysis data demonstrate
otherwise81. EPA's waste sampling data indicate that copper slag does not exhibit any characteristics of
hazardous waste at all but one of the facilities that generate the material. The Agency's cost and impact
analysis for slag is therefore limited to that one facility, Phelps Dodge/Playas, whose slag exhibited EP toxicity
for cadmium and lead. Similarly, non-confidential sampling data are available from one of the two facilities
generating calcium sulfate sludge; these data indicate EP toxicity for arsenic, cadmium, and selenium. Sludge
from both facilities is assumed to be potentially hazardous, therefore, cost impacts for both facilities have been
estimated. Costs and impacts have not been estimated for copper slag tailings, because the waste does not
exhibit any of the four hazardous waste characteristics and appears to pose low overall hazard, as discussed
above.
Copper Slag
Subtitle C
Under Subtitle C standards, generators of hazardous waste that is managed on-site must meet the
rigorous standards codified at 40 CFR Part 264 for hazardous waste treatment, storage, and disposal facilities.
Because copper slag is a solid, non-combustible material, and because under full Subtitle C regulation,
hazardous wastes cannot be permanently disposed of in waste piles, EPA has assumed in this analysis that the
ultimate disposition of copper slag would be in Subtitle C landfills. Because, however, current practice at the
potentially affected primary copper facility is disposal of slag in a wastepile, the Agency has assumed that the
facility would also construct a small temporary storage waste pile (with capacity of one week's waste
generation) that would enable the operator to send the slag to on-site disposal efficiently. To accommodate
the large waste volume generated at the Playas facility (almost 365,000 mt/yr), EPA believes that the least-cost
option would be for the facility operator to construct one on-site landfill that meets the minimum technology
standards specified at 40 CFR 264, rather than ship the material off-site to a commercial hazardous waste
landfill or build multiple landfills. Furthermore, EPA has adopted the conservative assumption that the
operator of the smelter would continue to dispose of its slag, rather than attempt to recycle it The Agency
recognizes, however, that given the large quantities of material generated and the high cost of Subtitle C waste
management (discussed more fully below), that the affected firm may well choose to recycle, or reduce the
generation rates of its smelter slag.
Subtitle C-Minus
A primary difference between full Subtitle C and Subtitle C-minus is the facility-specific application
of requirements based on potential risk from the hazardous special waste. Under the C-minus scenario, as
well as the Subtitle D-Plus scenario described below, the degree of potential risk of contaminating groundwater
8lAn exception to this general approach concerns the anode furnace slag generated at the ASARCO-Amarillo and Phelps Dodge-
El Paso facilities, both of which are stand-alone refineries. Because EPA has no sampling data on this specific component of copper
slag, and because all anode furnace slag is recycled by all facility operators, the Agency has assumed that generators would not incur
compliance costs related to management of this material in the absence of the Mining Waste Exclusion.
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Chapter 6: Primary Copper Processing 6-53
resources was used as a decision criterion in determining what level of protection (e.g., liner and closure cap
requirements) will be necessary to protect human health and the environment. The Playas facility was
determined to have a low potential to contaminate groundwater resources. Therefore, under Subtitle C-minus,
the facility would be allowed to continue to operate its present disposal wastepiles, though run-onyrun-off and
wind dispersal/dust suppression controls are assumed to be required for the unit, as well as groundwater
monitoring. In addition, the unit must undergo formal closure, including a cap of crushed stone, and post-
closure care must be maintained (e.g., leachate/run-off collection and treatment, cap maintenance, and
continued groundwater monitoring) for a period of thirty years.
Subtitle D-Plus
As under both Subtitle C scenarios, the facility operator would, under the Subtitle D-plus scenario,
be required to ensure that hazardous contaminants do not escape into the environment. Like the Subtitle C-
minus scenario, facility-specific requirements are applied to allow the level of protection to increase as the
potential risk to groundwater increases. As the Playas facility has low potential to contaminate groundwater
resources, Phelps Dodge is assumed to be allowed to continue operating its disposal wastepile under
Subtitle D-Plus. The wastepile would be retrofitted with run-on/run-off and wind dispersal/dust suppression
controls which, as with Subtitle C-minus, must be maintained through closure and the post-closure care period.
Groundwater monitoring and capping at closure is assumed to not be required for management units under
Subtitle D-Plus when the groundwater contamination potential is low, though wind dispersal/dust suppression
controls must be maintained.
Calcium Sulfate Wastewater Treatment Plant Sludge
Subtitle C
Under Subtitle C standards, generators of hazardous waste that is managed on-site must meet the
rigorous standards codified at 40 CFR Part 264 for hazardous waste treatment, storage, and disposal facilities.
Because copper calcium sulfate sludge is a slurry of non-combustible material, EPA has assumed in this
analysis that the sludge would be treated and solidified/stabilized in dual Subtitle C treatment surface
impoundments, and that the ultimate disposition of the stabilized sludge would be in a Subtitle C landfill.
To accommodate the portion disposed, EPA believes that, because of cost considerations, each facility operator
would construct two on-site treatment surface impoundments and one on-site landfill that meet the minimum
technology standards specified at 40 CFR 264, rather than ship the material off-site to a commercial hazardous
waste landfill.
Subtitle C-M/nus
A primary difference between full Subtitle C and Subtitle C-minus is the facility-specific application
of requirements based on potential risk from the hazardous sludge. Under the C-minus scenario, as well as
the Subtitle D-Plus scenario described below, the degree of potential risk of contaminating groundwater
resources was used as a decision criterion in determining what level of protection (e.g., liner and closure cap
requirements) would be necessary to protect human health and the environment Both facilities generating
potentially hazardous copper calcium sulfate sludge were determined to have a low potential to contaminate
groundwater resources. Therefore, under Subtitle C-minus, both facilities would be allowed to continue to
operate their present management units. Run-on/run-off controls are assumed to be required for the storage
impoundments and disposal units. Groundwater monitoring would be required for both facilities and would
continue through closure and the post-closure care period. In addition, the units must undergo formal closure,
including a cap of crushed stone underlain by a run-on/leachate collection system to remove the rainfall and
snowmelt that would be expected in short but intense surges. Post-closure care must be maintained (e.g.,
leachate/run-off collection and treatment, cap maintenance, and groundwater monitoring) for a period of thirty
years.
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6-54 Chapter 6: Primary Copper Processing
In addition to the cost differences between full Subtitle C versus Subtitle C-minus that are attributable
to the actual management units, an additional cost difference is associated with the relaxation of the sludge
stabilization/solidification requirements. Sludges are assumed to be disposed without stabilization/solidification
and the associated costs; in addition, the treatment units (i.e., settling ponds) used to separate sludge and
entrained water prior to cementation are no longer required.
Subtitle D-Plus
As under both Subtitle C scenarios, facility operators under the Subtitle D-plus scenario would be
required to ensure that hazardous contaminants do not escape into the environment. Like the Subtitle C-
Minus scenario, facility-specific requirements are applied to allow the level of protection to increase as the
potential risk to groundwater increases. As the two copper facilities with potentially hazardous copper
calcium sulfate sludge both have low potential to contaminate groundwater resources, the facilities are assumed
to be allowed to continue operating their disposal units under Subtitle D-Plus. The management units would
be retrofitted with run-on/run-off controls which must be maintained through closure and the post-closure care
period. Capping the units with crushed stone underlain by a run-on/leachate collection system (i.e., the same
as described in the Subtitle C-minus discussion above) is required and must be maintained through the post-
closure care period. Groundwater monitoring would not be required for these units because of the low
groundwater contamination potential.
In addition to the cost differences between full Subtitle C and Subtitle D-Plus that are attributable
to the actual management units, an additional cost difference is associated with the relaxation of the sludge
stabilization/solidification requirements. Sludges are assumed to be disposed without stabilization/solidification
and its associated costs; in addition, the treatment impoundments (i.e., settling ponds) used to separate sludge
and entrained water prior to cementation are no longer required.
6.6.2 Cost Impact Assessment Results
Copper Slag
Results of the cost impact analysis for the Playas smelter are presented for each regulatory scenario
in Exhibit 6-11. Under the Subtitle C scenario, Phelps Dodge's annualized regulatory compliance costs are
estimated to be just over $8.6 million more than baseline waste management costs (about 17 times greater).
Over S6.7 million of the increased compliance costs would be for new capital expenditures, or approximately
78 percent of the total.
Under the facility specific risk-related requirements of the Subtitle C-Minus scenario, costs of
regulatory compliance are, for the sector, about 82 percent less than the full Subtitle C costs. Phelps Dodge's
annualized compliance costs would be $1.1 million more than the baseline waste management costs (about 3
times greater than baseline). The primary savings over the full Subtitle C costs, due to the consideration of
risk potential, are the relaxation of technical requirements and the ability to use disposal wastepiles. New
capital expenditures, nearly 95 percent less than under full Subtitle C, would account for about $362,000 of
the incremental C-Minus compliance costs (about 34 percent of the annualized compliance cost).
Regulation under the Subtitle D-Plus program is assumed to require the same management controls
as under Subtitle C-Minus, with the exception that, because of the low risk classification, no groundwater
monitoring or capping at closure is required under this scenario. Phelps Dodge's annualized regulatory
compliance costs would be $471,000 more than the baseline waste management costs (about 2 times the
baseline cost). This represents a decrease of 89 percent from the Subtitle C compliance costs, and a decrease
of 38 percent from the Subtitle C-Minus compliance costs.
-------
Exhibit 6-11
Compliance Cost Analysis Results for Management of
Copper Slag from Primary Processing**'
Facility
Phelp* Dodge - Playa*. NM
Total:
MMMQMIMHI Cow
Annual Total
($000)
532
532
Subtitle C
Annual
Total
($000)
8.611
8.611
Total
Capital
($000)
45.312
45.312
Annual
Capital
($000)
6.761
6.761
tofy Coinpftanco}
Subtitle C-MInu*
Annual
Total
($000)
1.077
1.077
Total
Capital
($000)
2.424
2.424
Annual
Capital
($000)
362
362
Subtitle D-Plu*
Annual
Total
($000)
471
471
Total
Capital
($000)
970
970
Annual
Capital
($000)
145
145
o
o»
TJ
t
O
O
(a) Value* reported In thl* table ar* thoee computed by EPA'* co*t estimating model, and are Included for Illustrative purposes. The data, assumptions, and computational
method* underlying the** value* are such that EPA believe* that the compliance cost estimate* reported here are precise to two significant figures.
Costs have been estimated only for facilities for which sampling data Indicate that the waste would exhibit a RCRA hazardous waste characteristic.
Ol
U1
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6-56 Chapter 6: Primary Copper Processing
Copper Calcium Sulfate Sludge
Only two primary copper plants generate calcium sulfate sludge: Kennecott/Garfield, and
ASARCO/Hayden. Costs associated with regulatory compliance are shown in Exhibit 6-12. Both facilities
would incur costs under the Subtitle C scenario, with Kennecott/Garfield facing annualized compliance costs
of more than $10.0 million and ASARCO/Hayden almost S5.2 million. These costs represent increases of
almost 10 times current waste management costs. Annualized capital expenditures account for about half of
annualized compliance costs, at about $5.0 million at Kennecott/Garfield and $2.2 million at ASAR-
CO/Hayden. Other significant contributors to the increase in waste management costs include cement
stabilization costs (which are mostly an operating cost) and the costs of operating double lined settling ponds
and landfills.
Under the Subtitle C-Minus scenario, annualized compliance costs are estimated at $1.2 million for
Kennecott/Garfield, and $0.45 million for ASARCO/Hayden (about twice the baseline costs), a decrease for
the sector as a whole of 90 percent from the Subtitle C scenario. Relaxation of cementation requirements,
and the ability, due to low risk potential, to continue to operate their storage and disposal units with
retrofitted controls (e.g., run-on/run-off controls) account for the extremely large cost savings over the full
Subtitle C regulatory scenario.
Under the Subtitle D-Plus regulatory scenario, compliance-related waste management costs are 93
percent lower than Subtitle C, for the same reasons that Subtitle C-minus was less costly (e.g., no cementation,
no new units required). Costs were nearly 40 percent less than Subtitle C-minus, however, primarily because
the requirement for groundwater monitoring is waived for units located in low risk environments under this
scenario.
6.6.3 Financial and Economic Impact Assessment
To evaluate the ability of affected facilities to bear these regulatory compliance costs, EPA conducted
an impact assessment consisting of three steps. First, the Agency compared the estimated costs to several
measures of the financial strength of each facility (in the form of financial impact ratios) to assess the
magnitude of the financial burden that would be imposed in the absence of changes in supply, demand, or
price. Next, in order to determine whether compliance costs could be distributed to (shared among) other
production input and product markets, EPA conducted a qualitative evaluation of the salient market factors
that affect the competitive position of domestic copper producers. Finally, the Agency combined the results
of the first two steps to arrive at predicted ultimate compliance-related economic impacts on the copper
industry. The methods and assumptions used to conduct this analysis are described in Chapter 2 and in
Appendices E-3 and E-4 to this document, while detailed results are presented in Appendix E-5.
Financial Ratio Analysis
Copper Slag
EPA believes that Subtitle C regulation might impose significant financial impacts on the Playas
facility. As shown in Exhibit 6-13, the annualized incremental costs associated with waste management under
Subtitle C represent a significant portion of the value added (more than eight percent) by the Playas smelter.
Moreover, the ratio of annualized compliance capital costs to annual sustaining capital investments also
suggests a substantial economic impact.
Financial impacts under the Subtitle C-Minus scenario are much less severe than those under the full
Subtitle C scenario. The compliance costs as a percent of value added and value of shipments indicate only
slight impacts. In addition, compliance capital needs as a percent of sustaining capital are low, at less than
2 percent
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Chapter 6: Primary Copper Processing 6-57
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6-58 Chapter 6: Primary Copper Processing
Exhibit 6-13
Significance of Regulatory Compliance Costs for Management of
Copper Slag from Primary Processing^
Facility
CC/VOS
CC/VA
IR/K
Subtitle C
Phelps Dodge - Playas, NM
2.6%
8.4%
34.1%
Subtitle C-Minus
Phelps Dodge - Playas, NM
0.3%
1.1%
1.8%
Subtitle D-Plus
Phelps Dodge - Playas, NM
0.1%
0.5%
0.7%
CC/VOS = Compliance Costs as Percent of Sales
CC/VA = Compliance Costs as Percent of Value Added
IR/K = Annualized Capital Investment Requirements as Percent of Current Capital Outlays
Costs and impacts have been estimated for only those facilities for which sampling data indicate that the waste exhibits a
RCRA hazardous waste characteristic.
(a) Values reported in this table are based upon EPA's compliance cost estimates. The Agency believes that these
values are precise to two significant figures.
Financial impacts under the Subtitle D-Plus scenario decrease even from the Subtitle C-minus
impacts; the Playas facility would not be expected to be substantially affected under this regulatory scenario.
The compliance costs as a percent of value added and value of shipments indicate very low impacts to the
facility. Compliance capital needs as a percent of sustaining capital are negligible as well, at less than three
quarters of one percent.
Calcium SuHate Wastewater Treatment Plant Sludge
EPA believes that Subtitle C regulation might impose significant financial impacts on the Kennecott
and Hayden facilities. As shown in Exhibit 6-14, the annualized incremental costs associated with waste
management under Subtitle C represent a significant portion of both the value added and the value of
shipments for both facilities generating calcium sulfate sludge. Moreover, the ratio of annualized compliance
capital costs to annual sustaining capital investments also suggests potentially significant impacts for these
facilities.
Financial impacts under the Subtitle C-Minus scenario are much less severe than full Subtitle C
impacts. Compliance costs as a percent of value added and value of shipments indicate only slight impacts
at worst (one percent or less). Compliance capital needs as a percent of sustaining capital are also relatively
low, at less than 3 percent.
Financial impacts under the Subtitle D-plus scenario decrease even from the Subtitle C-minus
impacts; the two facilities are not expected to be significantly affected under this regulatory scenario.
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Chapter 6: Primary Copper Processing 6-59
Exhibit 6-14
Significance of Regulatory Compliance Costs for Management of
Calcium Sulfate WWT Plant Sludge from Primary Copper Processing<*'
Facility
Subtitle C
Kennecott - Garfield, UT
ASARCO - Hayden, A2
Subtitle C-Minus
Kennecott - Garfield, UT
ASARCO - Hayden, AZ
Subtitle D-Pluc
Kennecott - Garfield, UT
ASARCO - Hayden, AZ
CC/VOS
2.6%
1.7%
0.3%
0.1%
0.2%
0.1%
CC/VA
8.4%
5.4%
1.1%
0.5%
0.6%
0.3%
IR/K
21.4%
12.1%
2.3%
0.4%
1.7%
0.3%
CC/VOS = Compliance Costs as Percent of Sales
CC/VA = Compliance Costs as Percent of Value Added
IR/K = Annualized Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported in this table are based upon EPA's compliance cost estimates. The Agency believes that these
values are precise to two significant figures.
Market Factor Analysis
General Competitive Position
There have been extensive structural changes in the U.S. copper mining and processing industry since
the recession of the early 1980s. Coupled with the massive oil industry purchase and divestiture of copper
facilities in the late 1970s and mid 1980s, respectively, the present U.S. copper industry looks very different
from the U.S. copper industry of a decade ago. The major changes have included:
1. Closure of high-cost mining operations;
2. Modification of mining plans at operating mines that allow for lower cost exploitation
of mineral values. Generally this reflects a decrease in stripping ratios or an increase
in cut-off grade;
3. Extensive mechanization of mines, including modification of haulage methods;
4. Modernization of milling methods to improve scale economies and recovery,
5. Closure of several high-cost, non-competitive smelters;
6. Improvements in new smelter technology and environmental controls; and,
7. Increases in the production of low-cost solvent extraction-electrowinning (SX-EW)
copper.
These technical advances and competitive business decisions were coupled with extensive labor
negotiations that checked union wage increases and often rolled back benefits, particularly in the pension area.
Along with these labor agreements have been concessions by mines to share the profits and benefits from
increased productivity.
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6-60 Chapter 6: Primary Copper Processing
Since 1982, when the U.S. provided 17 percent of the world copper mine supply, the domestic copper
industry has rebounded to become a major mine producer, currently producing 21 percent of world supply.
Substantial increases in the price of copper and the expansion and modernization of the Bingham Canyon
(Garfield) mine and smelter complex in Utah have fueled the increase in copper production.
U.S. consumption has returned to the high levels of the late 1970s and early 1980s but still accounts
for only about 27 percent of world consumption as opposed to 30 percent in the late 1970s. U.S. facilities
(including secondary producers) are again accounting for over 80 percent of domestic requirements.
Potential for Compliance Cost Pass-Through
Labor Markets
Approximately 12,000 workers were employed in the copper sector in 1988, with an average salary
of $28,539. Imposing substantially lower wages to counteract compliance costs is not a likely scenario in the
copper processing industry. There have already been significant wage and benefit concessions and movement
in the opposite direction with regard to wages is likely over the next few years.
Raw Material Supply Markets
Because recent mergers and property acquisitions in the U.S. industry have resulted in extensive
vertical integration, the reduction of prices paid to suppliers is basically an accounting exercise (i.e., shifting
expenses from one profit center within a corporation to another). In addition, if copper producers are unable
to use the ore that the company generates to produce copper at competitive prices, they can instead sell the
concentrate on the world market. In fact, export of concentrate is already occurring; because smelter capacity
is less than concentrate production levels, excess U.S. concentrate production is largely exported
(approximately 15 percent of domestic mine production was exported in the form of concentrate in 1989).
In the case of suppliers which have concentrate and little smelter capacity, there may be some
opportunity to lower prices for their concentrate to compensate for higher compliance costs on the
smelter/refinery level. This will depend largely on costs at foreign smelters (including transport of concentrate
to the smelters) and whether low costs will allow foreign firms to outbid U.S. smelters for concentrate. If the
cost impacts on smelters and refineries are significant, several mines in the U.S. will be able to export their
concentrate on favorable terms, though their profit margins will be reduced.
Higher Prices
The copper metal market is a world market and, therefore, U.S. prices must be in line with world
prices. The U.S. producers enjoy only a marginal transport cost advantage in supplying U.S. domestic markets,
so that significant price increases are not possible. More importantly, only three of the ten domestic facilities
that produce refined primary copper would experience increases in waste management costs in the absence
of the Mining Waste Exclusion. It is extremely unlikely that these three facilities could successfully pass
through compliance costs to domestic consumers (even though in combination they account for more than 40
percent of domestic supply), given the structure of domestic and global copper markets.
Evaluation of Cost/Economic Impacts
All three facilities that generate a potentially hazardous special waste from primary copper processing
are expected to incur significant impacts under full Subtitle C regulation; Subtitle C-Minus with its regulatory
flexibility, however, would allow for RCRA Subtitle C regulation of these waste with significantly less, and in
some cases only marginal, financial impacts. Due to the international nature of the market, and the fact that
only one (if only slag is regulated) to three (if both slag and sludge are regulated) facilities would be affected,
producers experiencing regulatory impacts would be unlikely to be able to raise prices enough, if at all, to pass
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Chapter 6: Primary Copper Processing 6-61
through their compliance costs. Consequently, EPA believes that any incremental waste management costs
incurred by facilities as a result of a change in the regulatory status of the special wastes will be borne entirely
by these facilities. Nonetheless, because of the regulatory flexibility imparted by RCRA §3004(x), the Agency
does not believe that the continued profitability or long-term viability of the affected primary copper facilities
would necessarily be threatened by a change in the regulatory status of copper slag or calcium sulfate
wastewater treatment plant sludge.
6.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) potential for and documented
danger to human health and the environment; (2) the need for and desirability of additional regulation; and
(3) the costs and impacts of potential Subtitle C regulation.
Copper Slag
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of copper slag is moderate compared to the other mineral processing wastes
studied in this report. Data collected by EPA and submitted by industry indicate that most copper slag does
not exhibit any of the characteristics of hazardous waste, and hence, would not be subject to Subtitle C
regulation if it were to be removed from the Mining Waste Exclusion. However, at one facility (out of seven
that were tested), sampling data suggest that copper slag may exhibit the hazardous waste characteristic of EP
toxicity -- one sample of the 70 available to EPA for this study contained cadmium and lead in excess of the
EP toxicity regulatory levels. None of the slag samples that were analyzed using the SPLP leach test (EPA
Method 1312), however, contained constituents in concentrations that exceed the EP toxicity regulatory levels.
In addition, copper slag contains seven constituents at levels that exceed the risk screening criteria used in this
analysis by a factor of 10. All of these factors lead EPA to conclude that copper slag could pose a moderate
risk if mismanaged.
Based on an examination of the characteristics at the 10 active primary copper facilities and predictive
modeling, EPA believes that copper slag poses a low risk at most facilities. Almost all of the facilities are
located in areas with generally low-risk environmental and exposure characteristics (e.g., very low precipitation
and net recharge, large depths to ground water, minimal use of nearby surface and ground-water resources,
and great distances to potentially exposed populations). A possible exception is the facility in White Pine, MI.
Using the conditions at White Pine as a conservative model, EPA predicts low risks associated with potential
dispersal of slag contaminants in ground water and air. Erosion of contaminants into nearby surface waters,
however, could cause greater impacts. The Agency predicts that stormwater erosion from a copper slag pile,
if not controlled, could result in annual average surface water concentrations of lead, iron, and molybdenum
that exceed MCLs or irrigation guidelines, as well as copper concentrations that exceed criteria for the
protection of aquatic life. Surface water contamination of this magnitude, however, should not actually occur
at the White Pine facility because the slag dump at that facility is equipped with stormwater run-on/run-off
controls. Similarly, significant surface water contamination is not expected at the other sites because the
nearest surface waters are farther away and have a greater assimilative capacity than that reflected by the
conservative conditions that were modeled.
Documented damage cases also show that run-off from copper slag can contaminate surface waters.
In some cases, such problems have been eliminated through revised slag management practices, such as
collection and treatment of the run-off. At the Commencement Bay Superfund site, however, where slag was
used as ballast in a wet, low-lying area, control of the contaminated run-off has been more difficult.
Documented cases of damage to ground water at copper smelters was also identified. In all cases, however,
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6-62 Chapter 6: Primary Copper Processing
the extent to which slag is contributing to the contamination is unclear and there are more probable sources
of the observed contamination, such as unlined wastewater impoundments.
Likelihood That Existing Risks/Impacts Will Continue in the Absence of Subtitle C Regulation
At the 10 active copper facilities, the current waste management practices and environmental
conditions are expected to limit contaminant migration and exposures in the future in the absence of more
stringent Federal regulation. Only one of the active slag piles is lined with a synthetic material (asphalt), only
five are equipped with storm water run-on/run-off controls, and dust suppression is practiced at only two of
the piles. However, the potential for significant releases to ground and surface water is limited by the
extremely arid setting of most sites; in addition, the potential for significant airborne releases is limited by the
large particle size of the slag. The primary exception to this generalization is the potential for stormwater
erosion into surface water next to the White Pine facility, but the slag pile at this site is equipped with run-off
controls that should limit releases through that pathway. Conceivably, exposures could occur at these sites
in the future if people moved closer to the waste management units in the future or if ground water very near
the units is ever used (assuming that there is useable ground water in the arid settings of most sites).
However, considering the relatively moderate intrinsic hazard of this waste, significant exposures at these sites
are generally not expected.
There is a potential for the slag to be generated and managed at alternate sites that could be more
conducive to releases and risks than the 10 active copper facilities. Several companies have announced plans
for expanding existing facilities and building new facilities in entirely new locations (such as Texas City, TX).
In addition, there are numerous historical and on-going uses of copper slag at off-site locations, such as use
as a highway construction aggregate, a portland cement replacement in concrete, highway embankment mater-
ial, road or railroad ballast, and as grit in abrasive airblasting. For some off-site uses, such as road sanding,
health and environmental concerns have been raised and the use has been discontinued. For other uses, such
as airblast abrasive, little if any information on the health and environmental impacts appears to be available.
Presumably because most copper slag is generated and used in relatively arid areas of the country, the
Commencement Bay log-son yards are the only known example of damages resulting from off-site use.
The active copper processing facilities that generate slag are located in five states (Texas, Arizona,
Utah, Michigan, and New Mexico), all of which adopt the federal hazardous waste regulatory exclusion for
mineral processing wastes. The majority of these states do not vigorously regulate mineral processing wastes
in general, or copper slag in particular, under their solid waste regulations, even if there are provisions that
would allow them to do so. For example, both Utah and New Mexico specifically exempt mineral processing
wastes from their solid waste regulations. Moreover, Michigan apparently exempts copper slag generated at
the White Pine facility from solid waste regulation because the slag is reprocessed. Although Texas classifies
mineral processing wastes as industrial solid wastes, the copper processing facilities currently generating slag
are only required to notify the state of their waste management activities. All of the states appear to address
some or all of the copper processing wastes to some extent under surface water discharge permitting programs.
Both Arizona and New Mexico also have ground-water discharge permit programs, and Utah recently enacted
ground-water protection legislation that will require permits. Finally, although all of the states appear to have
fugitive dust emission control requirements that could apply to copper slag, the extent to which these
requirements are being applied to the slag is not clear.
Costs and Impacts of Subtitle C Regulation
Because of the moderate intrinsic risk potential of this waste and the fact that EPA waste sampling
data indicate that copper slag may exhibit the hazardous waste characteristic of EP tcxicity, the Agency has
evaluated the costs and associated impacts of regulating this waste as a hazardous waste under RCRA
Subtitle C. Because, however, data available to EPA indicate that copper slag is not EP toxic at most of the
facilities that generate it, the Agency has assumed that this waste would be EP toxic (hence, affected by a
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Chapter 6: Primary Copper Processing 6-63
change in regulatory status) at only the one facility (Phelps Dodge-Playas) at which a sample indicates
exceedances of EP toxicity regulatory levels.
Total costs of regulatory compliance at the Playas copper plant exceed $8.6 million annually under
the full Subtitle C scenario, while under the flexible standards of the Subtitle C-Minus scenario, costs would
be 82 percent lower, at just over SI million per year. Under the Subtitle D-Plus scenario, annual compliance
costs at the Playas facility would be less than $500,000, a 38 percent reduction from Subtitle C-Minus cost
impacts. Full Subtitle C compliance costs represent more than eight percent of the value added by the affected
facility, while impacts of the less stringent regulatory scenarios are modest. EPA's economic impact analysis
suggests that the operator of the potentially affected facility would have difficulty passing through any portion
of regulatory compliance costs that it might incur to product consumers, because it accounts for less than 15
percent of domestic production and would be the only facility expected to incur regulatory compliance costs
if copper slag were to be removed from the Mining Waste Exclusion. Therefore, EPA believes that the
operators of the Playas facility would have to bear in full any incremental costs associated with regulation of
copper slag under Subtitle C, but that the associated impacts under modified Subtitle C standards would not
threaten the continued viability of this facility.
Copper Slag Tailings
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of copper slag tailings is relatively low compared to the other mineral processing
wastes studied in this report. The tailings do not exhibit any of the four characteristics of hazardous waste,
and only 5 constituents were detected in the tailings in concentrations that exceed the conservative risk
screening criteria used in this analysis by a factor of 10 or more.
Based on the Agency's review of existing management practices and release/exposure conditions, as
well as the lack of documented cases of damage caused by copper slag tailings, the overall hazard associated
with management of the tailings appears to be low. Although the tailings are generated as a slurry and co-
managed with liquids that could serve as a leaching medium, the concentrations of only three contaminants
in the leachate exceed the screening criteria by a factor of 10 or greater. Furthermore, ground water at the
three facilities that actively generate and manage the tailings is either very deep (and thus somewhat protected)
or currently is not used within a mile downgradient of the waste disposal site. It is possible, however, that
ground water close to the slag tailings units could be used sometime in the future. Except for the White Pine
facility, where there is a moderate potential for the tailings to migrate to surface water, the potential for the
tailings to cause significant surface water contamination appears very remote. Airborne dusting from the
tailings piles can and does occasionally occur. Windblown dust from the piles should be studied further and,
if necessary, controlled to prevent possible inhalation exposures to arsenic and chromium.
Likelihood That Existing Risks/Impacts Will Continue in the Absence of Subtitle C Regulation
In the absence of more stringent federal regulation, there will continue to be a potential for slag
tailings contaminants to migrate into ground water, surface water, and air at some of the active facilities.
However, considering the relatively low intrinsic hazard of the tailings, significant exposures at these sites
would not be expected unless ground water very near the tailings piles is used or if people moved very close
to the piles in the future. The tailings are susceptible to wind erosion when dry, and windblown dust after
closure could be a problem, especially in the arid settings of two of the plants. EPA believes that, after
closure, measures should be taken to control windblown dust and associated potential inhalation risks to
existing and potential future populations.
There is only a slight potential for the tailings to be generated and managed at alternate sites in the
future. As discussed above for copper slag, some companies have announced plans to construct new copper
processing facilities, but it is uncertain if any of the new facilities would generate slag tailings (not all copper
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6-64 Chapter 6: Primary Copper Processing
facilities generate slag tailings). Also, given the quantities of tailings involved, it is unlikely that the tailings
would be disposed off-site. Slag tailings have been used off-site in the past for highway embankment material
and road base, and thus it is conceivable that the tailings could be used off-site again in the future. None of
the facilities that currently generate the tailings, however, ship the tailings off-site for use.
The three copper processing facilities that generate slag tailings are located in Arizona, Utah, and
Michigan, all of which exclude copper slag tailings from regulation as hazardous waste. In addition, none of
these states vigorously regulate mineral processing wastes in general, or copper processing wastes in particular,
under their solid waste regulations. For example, Utah specifically exempts mineral processing wastes from
its solid waste regulations. Arizona has a ground-water discharge permit program, and Utah recently enacted
ground-water protection legislation that will require permits. All three states appear to have general fugitive
dust emission control requirements that could apply to copper processing wastes, but the extent to which these
requirements are being applied is not clear.
Costs and Impacts of Subtitle C Regulation
Because of the low risk potential of copper slag tailings, the complete absence of documented
damages associated with the management of this material, and the fact that this waste does not exhibit any
characteristics of hazardous waste, EPA has not estimated the costs and associated impacts of regulating
copper slag tailings under RCRA Subtitle C.
Calcium Sulfate Wastewater Treatment Plant Sludge
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of calcium sulfate wastewater treatment plant sludge from copper processing is
relatively high compared to the other mineral processing wastes studied in this report Although none of the
sludge samples that were analyzed using the SPLP leach test (EPA Method 1312) contained constituents in
concentrations above the EP toxicity regulatory levels, several sludge samples analyzed with the EP leach test
were found to be EP toxic. Arsenic and selenium were measured in EP leachate in excess of the EP toxicity
regulatory level in seven out of seven samples (from the one facility tested). Cadmium was also measured in
EP leachate in excess of the EP toxicity level in six out of seven samples. In addition to these exceedances
of the EP toxicity regulatory levels, calcium sulfate sludge contains 10 constituents in concentrations that
exceed the risk screening criteria used in this analysis by more than a factor of 10. All of these factors lead
EPA to conclude that the sludge could pose a significant risk if mismanaged.
Based on a review of existing management practices and facility settings, as well as predictive modeling
results, EPA believes that the hazards associated with calcium sulfate sludge are generally low at the two
facilities where it is currently generated. Both facilities are located in very arid locations (Hayden, AZ and
Garfield, UT) where there is little precipitation and recharge to ground water. Even the liquids used to slurry
the sludge into the impoundments are expected to quickly evaporate, rather than seep into the ground.
Considering this lack of water to carry sludge contaminants to the subsurface, along with the depths to ground
water and the tendency of the sludge contaminants to bind to soil, EPA predicts that it would take more than
200 years for contaminants to migrate from the sludge into ground water. If the impoundment at the Hayden
facility is conservatively assumed to be filled with sludge and not equipped with a cover or storm water run-off
control system, the Agency predicts that erosion from the impoundment could cause arsenic and silver
concentrations in the nearby Gila River that exceed health and ecological protection benchmarks. However,
because the impoundment at Hayden is in fact equipped with run-off controls, surface water contamination
of this magnitude is not actually expected. The potential for significant releases of windblown dust from the
sludge appears very remote, because the surface of the sludge dries to form a crust that is relatively resistant
to wind erosion.
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Chapter 6: Primary Copper Processing 6-65
No cases of documented damage caused by the sludge were discovered by EPA. This finding supports
the conclusion that, as currently managed, the sludge poses a generally low hazard.
Likelihood That Existing Risks/Impacts Will Continue in the Absence of Subtitle C Regulation
Even though the intrinsic hazard of calcium sulfate sludge is high, the risks at the two facilities that
currently generate the sludge are expected to remain low in the future in the absence of more stringent federal
regulation. This is because the sludge appears to be reasonably well managed at present, and the potential
for significant releases and exposures is generally precluded by the environmental conditions at these two sites.
However, there is a potential for the sludge to be generated and managed at alternate sites in the
future, especially if the sludge is not regulated under Subtitle C of RCRA. As discussed previously, several
companies have announced plans to expand production capacity at existing sites and to construct new copper
processing facilities in entirely new locations. Some of these new facilities and locations may be more
conducive to releases and risks than the two active sites. Also, although the sludge has not been used or
disposed off-site in the past and there are no plans to ship the sludge off-site in the near future, any off-site
shipments of the sludge could pose a significant risk if the sludge is not properly managed.
The existing regulatory programs in Arizona and Utah provide only limited controls over the
management of calcium sulfate sludge from copper processing. Both states exempt the sludge from hazardous
waste regulation, and neither state vigorously regulates the sludge under its solid waste regulations. In fact,
Utah specifically exempts mineral processing wastes from its solid waste regulations. Arizona classifies the
sludge as solid waste, but to date has not focused its regulatory efforts on the facilities under study. However,
Arizona does have a ground-water discharge permit program, and Utah recently enacted ground-water
protection legislation that will require permits. In addition, both states appear to have general fugitive dust
emission control requirements that could apply to calcium sulfate sludge, but the extent to which these
requirements are being applied is not clear.
Cost and Impacts of Subtitle C Regulation
EPA has evaluated the costs and associated impacts of regulating calcium sulfate wastewater treatment
plant sludge from primary copper production as a hazardous waste under RCRA Subtitle C. EPAs waste
characterization data indicate that this waste exhibits the hazardous waste characteristic of EP toxicity at the
one (of two) active facilities for which sampling data were available. EPA has employed the conservative
assumption that the calcium sulfate sludge would also be EP toxic at the other (ASARCO-Hayden) facility,
the Agency's cost and impact estimates reflect this assumption and therefore may overestimate the impacts
of prospective regulation.
Costs of regulatory compliance under the full Subtitle C scenario exceed $5 million annually at both
facilities; these costs would impose potentially significant economic impacts on the operators of the affected
plants. Application of the more flexible Subtitle C-Minus regulatory scenario would result in compliance costs
that are about 90 percent lower, ranging from about $450,000 to just under $1.2 million annually. Costs under
the Subtitle D-Plus scenario are approximately 40 percent lower than under Subtitle C-Minus, because of
further relaxation of waste management unit design and operating standards.
Subtitle C compliance costs would comprise a significant fraction of the value added by copper
smelting/refining operations at both affected facilities; this ratio exceeds eight percent at the Garfield facility
and five percent at the Hayden plant. Compliance cost ratios under the Subtitle C-Minus and Subtitle D-Plus
scenarios are substantially lower, not exceeding one percent at either facility. EPA's economic impact analysis
suggests that the domestic copper industry is currently stronger than it has been in recent years, but would
have limited ability to pass through compliance costs in the form of significantly higher prices to product
consumers. Moreover, because not all domestic producers would be affected or affected equally (the two
potentially affected facilities account for about 30 percent of domestic capacity), it is improbable that the
affected facilities would be able to obtain higher product prices in any case. Nonetheless, given the moderate
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6-66 Chapter 6: Primary Copper Processing
impacts predicted under the flexible management standards of the Subtitle C-Minus scenario, EPA believes
that a decision to remove calcium sulfate sludge from the Mining Vfaste Exclusion would not threaten the
long-term profitability and hence, economic viability, of the facilities generating this waste.
Finally, EPA is not aware of any significant recycling or utilization initiatives that would be hampered
by a change in the regulatory status of this waste. To date, there have not been any attempts to develop
management alternatives to disposal. Impacts on the Agency-wide policy objective of waste minimization are
unclear. Calcium sulfate sludge is a pollution control residual that is generated by the treatment of acid plant
blowdown and process wastewaters at primary copper smelter/refineries. Because these aqueous waste streams
often exhibit characteristics of hazardous waste and have themselves been recently removed from the Mining
Waste Exclusion, they will in the future require treatment under RCRA Subtitle C standards. If calcium
sulfate sludge were to be regulated as a hazardous waste, facility operators might be more inclined to use
treatment methods that generate lesser quantities of more concentrated sludge (e.g., by using caustic instead
of lime). In this way, the total quantity of hazardous waste requiring disposal would decrease, though the
inherent hazard posed by the treatment sludge would increase. The Agency plans to explore this issue further
prior to the Regulatory Determination.
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Chapter 7
Elemental Phosphorus Production
The elemental phosphorus industry consists of five facilities that, as of September 1989, were active
and reported generating a mineral processing special waste: furnace slag. The data included in this chapter
are discussed in additional detail in a technical background document in the supporting public docket for this
report.
7.1 Industry Overview
Elemental phosphorus is used solely as a process input to produce a wide array of phosphorus
chemicals. As a chemical manufacturing feedstock, it may be used directly, or oxidized and condensed to
produce a high-purity "furnace-grade" phosphoric acid. Furnace-grade acid, in turn, is a feedstock for the
production of sodium phosphates, such as sodium tripolyphosphate, a detergent builder, which historically has
been a major product, and additional sodium phosphates (e.g., trisodium phosphate, sodium hexametaphos-
phate, tetrasodium pyrophosphate) which are used in cleaners, water treatment, and foods.1 Furnace-grade
acid is also used to manufacture calcium phosphates for animal feed, dentifrices, foods, and baking powders.
Another grade of furnace process acid is technical-grade acid, which is primarily used to clean metals.
The five elemental phosphorus production facilities are located near phosphate rock reserves in areas
where the cost of the large amount of energy required to operate the furnaces is relatively low. Facilities are
found in central Tennessee, Montana, and Idaho (see Exhibit 7-1). The dates of initial operation for these
facilities range from 1938 at Mt. Pleasant to 1952 at Soda Springs and Columbia. Except for the Silver Bow
facility, all facilities report having modernized their production operations; the Soda Springs facility was
upgraded in 1978 and the remaining three plants were modernized in 1988.2 The reported 1988 elemental
phosphorus production for the sector was 311,000 metric tons.3 The sector-wide capacity utilization was,
therefore, 91 percent during that year. Capacity data are presented in Exhibit 7-1.
Exhibit 7-1
Domestic Elemental Phosphorus Producers
Owner/Operator
FMC Corporation
Monsanto Company
Occidental Chemical
Stauffer(e)
Stauffer**
Location
Pocatello, JD
Soda Springs, ID
Columbia, TN
Mt Pleasant, TN
Silver Bow, MT
Capacity")
(metric ton«)(b>
125,000
86,000
52,000
41,000
38,000
(a) SRI International, 1967. Directory of Chemical Producers-United States. 1987 Ed.; p. 869.
(b) Capacity data is on a P4 basis.
(c) Rhone-Poulenc is the parent company.
1 Bureau of Mines, 1985 and 1987. Minerals Yearbook. 1987 Ed.; p. 677., and Mineral Facts and Problems. 1985 Ed.; p. 584.
2 FMC Corp., Monsanto Co., Occidental Chemical Co., Suuffer Chemical Co. 1989. Company Responses to the "National Survey
of Solid Wastes from Mineral Processing Facilities," U.S. EPA, 1989.
3 Production statistics reported by three of the five facilities in the elemental phosphorous industry are confidential; because the three
facilities are each owned by a different company, however, summary statistics for the sector can be reported without disclosing the facility-
specific confidential data.
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7-2 Chapter 7: Elemental Phosphorus Production
Production of phosphate rock has steadily increased since 1986, when production fell off by more than
10 percent of the 1985 total. Most of the increase in production throughout the late 1980s however, was due
to phosphate rock sold or used for wet process phosphoric acid production. The quantity of phosphate rock
used in domestic elemental phosphorus production actually decreased from 3.2 million metric tons in 1986
to 3.0 million metric tons in 1987.4
In elemental phosphorus production, sized phosphate rock or sintered/agglomerated phosphate rock
fines are charged to (introduced into) an electric arc furnace together with coke (a reducing agent) and silica
(a flux), as shown in Exhibit 7-2.5 The phosphorus contained in the rock is both liberated from the rock
matrix and chemically reduced by the operation.
The process generates calcium silicate slag and ferrophosphorus, which are tapped from the bottom
of the furnace in molten form, and carbon monoxide (CO) off-gases, which contain volatilized phosphorus.
The gas is treated using a precipitator to remove impurities and the cleaned gas, still containing the gaseous
phosphorus, is condensed using water to produce liquid elemental phosphorus. Following this treatment step,
the off-gas is typically routed to the ore sintering furnaces for use as fuel, though it may also be treated and
released. Treatment residuals (e.g., off-gas solids) are either recycled or disposed. The molten residues are
either air- or water-cooled, (Le., solidified). Ferrophosphorus is typically sold as a byproduct. The calcium
silicate furnace slag, the special mineral processing waste, is generally accumulated in storage piles, then sold
and/or disposed.
Exhibit 7-2
Elemental Phosphorus Production
PROCESS Cokei I Silica
Calcined .
Phosphate Ore
Electr
Furno<
c
:e
k n • •!
_k
horus
Liquid
Phosphorus
SPECIAL WASTE ^Calcium Silicate^
MANAGEMENT
Legend
Production Operation
Special Waste
o
Waste Management Unit
4 William F. Stowasser, U.S. Bureau of Mines, "Elemental Phosphorus," Minerals Yearbook. 1987 Ed., p. 679.
5 Environmental Protection Agency, 1984. Evaluation of Waste Management for Phosphate Processing. Prepared by PEI Associates
for U.S. EPA, Office of Research and Development, Cincinnati, OH; August, 1986.
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Chapter 7: Elemental Phosphorus Production 7-3
7.2 Waste Characteristics, Generation, and Current Management Practices
The mineral processing special waste generated by elemental phosphorus production, furnace slag,
is a solid material at ambient temperatures, although it usually is generated in a molten form. The slag is
typically a light gray, heavy, extremely hard, and porous material. After cooling from its molten state, the slag
is broken into cobble-to-boulder-size fragments. EPA analyses of this waste indicate that the solidified slag
is a glass-like material that contains its constituents in a vitrified matrix. Elemental phosphorus slag is
composed primarily of silicon and calcium and may contain radionuclides, including thorium-232, uranium-238,
and decay products of these two radionuclides, such as radium-226.
Using available data on the composition of elemental phosphorus slag, EPA evaluated whether this
waste exhibits any of the four hazardous waste characteristics: corrosivity, reactivity, ignitability, and extraction
procedure (EP) toxicity. Based on available information, EPA does not believe that elemental phosphorus
slag exhibits any of the four characteristics of hazardous waste. Data are available on the concentrations of
all eight inorganics with EP toxicity regulatory levels and, with the exception of chromium, all of these
constituents are present in EP leachate in concentrations that are at least two orders of magnitude below the
regulatory level, that is, below drinking water levels. The maximum chromium concentration observed in the
leachate is one order of magnitude below the EP toxicity regulatory level.
Furnace slag generation rate data were reported as non-confidential information by two of the five
elemental phosphorus production facilities, Columbia and Silver Bow, who reported waste generation rates
of approximately 354,000 and 272,000 metric tons, respectively. The aggregate industry-wide generation of slag
by the five facilities was approximately 2.6 million metric tons in 1988, yielding a facility average of over
526,000 metric tons per year.6 The sector-wide ratio of metric tons of slag to metric ton of elemental
phosphorus was 8.4 in 1988; waste-to-product ratios ranged from 8.0 (average for the three facilities submitting
confidential information) to 10.0 (at each of the other two facilities).
Two management practices predominate throughout the sector: 1) the sale of the slag for use as a
construction material (e.g., as an aggregate) and 2) storage or disposal of the furnace slag in waste piles.
Three facilities sold from 35 to 43 percent of the slag that they generated in 1988; the remainder of the slag
was placed in "stockpiles." Of the two remaining facilities, the Columbia plant reported selling all of its slag,
while the Silver Bow facility reported disposing all of its slag in a "slag pile." In 1988, the quantity of slag sent
to disposal waste piles at the five facilities ranged from 0 to greater than 500,000 metric tons per facility,
averaging 320,000 metric tons. As of 1989, stockpile areas at the five facilities ranged from 5 to 38 hectares
(12 to 95 acres) per facility. The total quantity of slag accumulated in these piles in 1988 ranged from
1,500,000 to 21,000,000 metric tons per facility.7
With regard to environmental media protection controls, only the Soda Springs, Idaho, facility reports
practicing dust suppression on its on-site waste piles, and none of the facilities report the use of liners or
leachate collection systems to limit infiltration through the piles.
7.3 Potential and Documented Danger to Human Health and the Environment
In this section, EPA discusses two of the study factors required by §8002(p) of RCRA: (1) potential
danger (i.e., risk) to human health and the environment; and (2) documented cases in which danger to human
health and/or the environment has been proven. Overall conclusions about the hazards associated with
elemental phosphorus slag are based on these two study factors and are presented at the end of this section.
6 Waste generation data that three facilities requested be confidential can be summed together and presented without revealing
confidentiality, as the three facilities are owned by different companies.
7 Stockpile area and accumulated quantity were not reported for two of the facilities.
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7-4 Chapter 7: Elemental Phosphorus Production
7.3.1 Risks Associated With Elemental Phosphorus Slag
Any potential danger to human health and the environment posed by elemental phosphorus furnace
slag depends on the presence of hazardous constituents in the slag and the potential for exposure to these
constituents.
Constituents of Concern
EPA identified chemical constituents in furnace slag that may present a hazard by collecting data on
the composition of the slag and evaluating the intrinsic hazard of the slag's constituents.
Data on Elemental Phosphorus Slag Composition
EPAs characterization of elemental phosphorus slag and any leachate that it might generate is based
on data from four sources: (1) a 1989 sampling and analysis effort by EPAs Office of Solid Waste (OSW);
(2) industry responses to a RCRA §3007 request in 1989; (3) sampling and analysis conducted by EPAs Office
of Research and Development (ORD) in 1984; and (4) literature addressing the radiological properties and
hazards of elemental phosphorus slag. These data provide information on the concentrations of 20 metals,
8 radionuclides, gross alpha and beta radiation, and a number of other inorganic constituents (e.g., phosphate,
phosphorus, fluoride, chloride, sulfate, ammonia, and nitrate) in total and leach test analyses. Three of the
five elemental phosphorus facilities are represented by these data: Rhone-Poulenc/Stauffer's facilities in Mt.
Pleasant, Tennessee and in Silver Bow, Montana, and the FMC Corporation plant in Pocatello, Idaho.
Concentrations in total sample analyses of the slag are consistent for most constituents across all data
sources and facilities. However, cadmium concentrations for the FMC facility in Pocatello are more than an
order of magnitude higher than in any other analyses. Constituent concentrations obtained from leach test
analyses of the slag are also generally consistent across the data sources, types of leach tests (i.e., EP, SPLP,
and TCLP), and facilities.
Process for Identifying Constituents of Concern
As discussed in detail in Section 2.2.2, the Agency evaluated the waste composition data summarized
above to determine if elemental phosphorus slag or its leachate contain any chemical or radiological
constituents that could pose an intrinsic hazard, and to narrow the focus of the risk assessment. The Agency
performed this evaluation by first comparing constituent concentrations to screening criteria and then by
evaluating the environmental persistence and mobility of any constituents that are present in concentrations
that exceed the screening criteria. These screening criteria were developed using assumed scenarios that are
likely to overestimate the extent to which elemental phosphorus slag constituents are released to the
environment and migrate to possible exposure points. As a result, this process eliminates from further
consideration those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic ecosystems, and water resources (see Exhibit 2-3). Given the conservative (i.e., overly
protective) nature of these screening criteria, contaminant concentrations in excess of the criteria should not,
in isolation, be interpreted as proof of hazard. Instead, exceedances of the criteria indicate the need to
evaluate the potential hazards of the slag in greater detail.
Identified Constituents of Concern
Exhibits 7-3 and 7-4 present the results of the comparisons for elemental phosphorus slag total
analyses and leach test analyses, respectively, to the screening criteria described above. These exhibits list all
constituents for which sample concentrations exceed a screening criterion.
Of the 31 constituents analyzed in elemental phosphorus slag solids, only arsenic, cadmium,
chromium, radium-226, and uranium-238 concentrations exceed a screening criterion (see Exhibit 7-3). All
-------
Chapter 7: Elemental Phosphorus Production 7-5
Exhibit 7-3
Potential Constituents of Concern in
Elemental Phosphorus Slag Solids(a)
Potential
Constituents
of Concern
Chromium
Arsenic
Radium-226
Uranium-238
Cadmium
No. of Time*
Constituent
Detected/No, of
Analyse*
for Constituent
4/5
3/5
6/6
1/1
3/5
Human Health
Screening Criteria04
tnhafatjon"
Ingestion*
Radiation**4
Inhalation*
Radiation*®
Inhalation"
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
4/5
3/5
4/6
1/1
1 /1
t/5
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
2/2
2/2
2/3
1 /1
1 /1
1 12
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that
exceeds a relevant screening criterion. The conservative screening criteria used in this analysis are listed in
Exhibit 2-3. Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion, inhalation, or all radiation pathways.
Human health effects from ingestion and inhalation include both cancer risk and noncancer endpoints. Ingestion or
inhalation screening criteria noted with an '*' are based on a 1x10"* lifetime cancer risk; others are based on noncancer
effects. 'Radiation* entries are based on cancer risks from all radiation pathways.
(c) Includes direct radiation from contaminated land and inhalation of radon decay products.
of these constituents are metals or other inorganics that do not degrade in the environment Chromium and
radium-226 were detected in most of the samples analyzed (80 to 100 percent), and their concentrations in
most analyses (approximately 70 to 80 percent) exceeded the screening criteria. Only cadmium and chromium
were detected in concentrations that exceed the screening criteria by more than a factor of 10, however.
These exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• Chromium, cadmium, and uranium-238 concentrations in the slag may pose a cancer
risk of greater than IxlO'5 if dust from the slag piles is blown into the air in a
concentration that equals the National Ambient Air Quality Standard for particulates
and then is inhaled by nearby individuals.
• Arsenic concentrations in the slag could pose a cancer risk of more than IxlO'5 if the
slag is incidentally ingested on a routine basis (which could occur if access to closed
piles is not restricted or if the slag is used off-site in an unrestricted manner that could
allow people to come into direct contact with slag).
• The concentrations of uranium-238, radium-226, and other members of the uranium-238
decay chain could pose a radiation hazard if the slag is allowed to be used in an
unrestricted manner. For example, as discussed in more detail in the next section, direct
radiation doses and doses from the inhalation of radon could be unacceptably high if
the slag is used in construction material or if people were allowed to build homes on
top of the slag.
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7-6 Chapter 7: Elemental Phosphorus Production
Exhibit 7-4
Potential Constituents of Concern in
Elemental Phosphorus Slag Leachate(a)
Potential
Constituents
of Concern
Phosphorus
Fluoride
Arsenic
Manganese
Aluminum
Phosphate
Chromium
Zinc
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
3/3
3/3
4/6
4/5
4/5
3/3
t/S
3/5
Screening Criteria'"*
Aquatic Ecological
Human Health
Resource Damage
Human Health*
Resource Damage
Aquatic Ecological
Aquatic Ecological
Resource Damage
Aquatic Ecological
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
3/3
3/3
2/3
4/6
3/5
3/5
2/3
1/6
1/5
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
2/2
2/2
2/2
2/2
2/2
2/2
1 12
1/2
1 12
(a) Constituents listed in this table are present In at least one sample from at least one facility at a concentration that
exceeds a relevant screening criterion. The conservative screening criteria used in this analysis are listed in
Exhibit 2-3. Constituents that were not detected in a given sample were assumed not to be present in the sample.
The constituent concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. 'Human health' screening
criteria noted with an '*' are based on a 1x10* lifetime cancer risk; others are based on noncancer effects.
Based on a comparison of EP leach test concentrations of 29 constituents to the surface and ground-
water pathway screening criteria (see Exhibit 7-4), only 8 constituents (i.e., arsenic, aluminum, chromium,
manganese, fluoride, phosphorus, phosphate, and zinc) exceed the water-based criteria. All of these
constituents are also metals or other inorganics that do not degrade in the environment. Chromium and zinc
appear to be of less concern because they were detected less frequently in the samples analyzed (less than 60
percent of the samples), and their concentrations exceeded the screening criteria in less than 20 percent of the
samples. Only manganese and phosphorus were measured in concentrations that exceed the screening criteria
by more than a factor of 10. Despite these exceedances of the screening criteria, however, none of the samples
contained any constituents in excess of the EP toxicity regulatory levels.
These.exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• If slag leachate is released to ground water and diluted by a factor of 10 or less during
migration to a downgradient drinking water well, arsenic and fluoride concentrations
could pose a health risk if ingested on a long-term basis without treatment The diluted
arsenic concentration could cause a cancer risk greater than IxlO"5.
• Concentrations of aluminum, phosphorus, phosphate, and zinc in slag leachate exceed
the aquatic ecological screening criteria, suggesting that these contaminants could
present a threat to aquatic ecological receptors if the leachate migrates (with 100-fok
dilution or less) to surface waters.
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Chapter 7: Elemental Phosphorus Production 7-7
• If slag leachate is released to ground water and diluted by a factor of 10 or less, the
resulting concentrations of chromium, manganese, and fluoride could exceed the
drinking water maximum contaminant level, potentially restricting future use of the
ground water as a resource.
Although radionuclides in the slag solids appear to present a potential hazard, no radionuclides were
detected at levels of concern in the slag leachate. Both radium-226 and gross beta contamination were
analyzed in EP leach tests of the slag. The measured radium-226 concentrations ranged from 0.5 to 1.6 pCi/1,
well below the maximum contaminant level of 5 pCi/1 in drinking water. The measured gross beta
concentrations ranged from 37 to 140 pCi/1, with an average of 83 pCi/1. While these values exceed the gross
beta concentration recommended for drinking water,8 50 pCi/1, it is likely that the leachate concentration
would be diluted by more than a factor of three if released to ground water. Therefore, any gross beta
contamination in ground water caused by the release of the slag leachate is expected to be below the 50 pCi/1
guideline.
These exceedances of the screening criteria, by themselves, do not demonstrate that the slag poses
a significant risk, but rather indicate that the slag may present a hazard under a very conservative, hypothetical
set of release, transport, and exposure conditions. Tb determine the potential for the slag to cause significant
impacts, EPA proceeded to the next step of the risk assessment to analyze the actual conditions that exist at
the facilities that generate and manage the waste.
Release, Transport, and Exposure Potential
This analysis considers the potential for direct radiation exposures associated with the off-site use of
elemental phosphorus slag, as well as potential releases and exposures through the ground-water, surface water,
and air pathways as the slag was generated and managed at the five elemental phosphorus production plants
in 1988. For this analysis, the Agency did not assess risks associated with variations in waste management
practices or potentially exposed populations in the future because of a lack of data on which to base
projections of future conditions.
Direct Radiation Exposure Potential
As discussed in Section 7.5, elemental phosphorus slag has been widely used for many years for a
variety of purposes. For example, in the Idaho and Montana area, the slag has been used as an aggregate in
concrete and asphalt, railroad ballast, roadbed fill, and farm road gravel. It has also been used in the
construction of homes, buildings, streets, sidewalks, parking lots, school playgrounds, and other structures.
Many of these uses can cause increased radiation exposure to people living or working near the slag-
bearing materials. Exposure is principally from direct gamma radiation emitted from radionuclides contained
in the slag, but there is also a possibility for radiation exposure through the inhalation of radon decay products
that may accumulate in the indoor air of structures built over or with the slag. Inhalation of slag dust
originating from road traffic is also a possible exposure pathway.9
A recent EPA study10 provides estimates of the direct radiation exposures and risks caused by the
off-site use of elemental phosphorus slag in Pocatello and Soda Springs, Idaho. Exposure to outdoor sources
(e.g., slag used in street paving) was estimated to be the greatest contributor to radiation doses in Pocatello.
Average gamma-ray doses in Pocatello caused by the slag were estimated to be 14 millirem/year, posing a
8 No maximum contaminant level for grots beta contamination has been established, but compliance with 40 CFR 141.16 may be
assumed if gross beta concentrations are less than 50 pCi/1.
9 Conference of Radiation Control Program Directors, 1981. Natural Radioactivity Contamination Problems. Report No. 2, Report
of the Committee, August 1981, p. 28.
10 Environmental Protection Agency Study, 1990. Idaho Radionuclidc Study. Office of Research and Development, Las Vegas Facility,
Las Vegas, NV, April 1990.
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7-8 Chapter 7: Elemental Phosphorus Production
lifetime fatal cancer risk of 4x10"*. Calculated maximum doses and risks in Pocatello were roughly a factor
of 10 higher. In Soda Springs, exposure to direct radiation within the home, caused by the use of slag in home
foundations, was determined to be the greatest contributor to radiation doses. Average gamma-ray doses in
Soda Springs caused by the slag were estimated to be 52 millirem/year, posing a lifetime risk of fatal cancer
of 1.4xlO"3. Doses and cancer risks to the maximally exposed individual in Soda Springs were 205
millirem/year and 6xlO"3, respectively. While these risk estimates are presented in the EPA study, the Agency
notes that the actual risks in Pocatello and Soda Springs could be roughly a factor of two higher.11 For
comparison, EPAs environmental radiation standards in 40 CFR 190 require operations in the uranium fuel
cycle (including nuclear reactor operations) to keep radiation doses to members of the general public to less
than 25 millirem/year.
While the study in Pocatello and Soda Springs did not detect a radon problem caused by the
elemental phosphorus slag, elevated concentrations of radon in indoor air caused by the slag have been
detected in other areas of the country. For example, indoor radon measurements conducted in 1,771 homes
located in Butte, Montana revealed that 243 homes (14 percent) had indoor radon daughter concentrations
above 0.02 working level,12 attributable to elemental phosphorus slag.13 For comparison, EPAs cleanup
standards in 40 CFR 192 for soils near inactive uranium mill tailings sites limit the concentration of indoor
radon decay products to 0.02 working level.
Ground-Water Release, Transport, and Exposure Potential
EPAs waste characterization data discussed above indicate that a number of constituents may leach
from the elemental phosphorus slag at concentrations above the screening criteria. Considering only those
contaminants that are mobile in ground water (given the existing slag management practices and neutral pH
conditions that are expected), elemental phosphorus slag stockpiles could release arsenic, chromium, fluoride,
phosphorus, and phosphate at concentrations that exceed the screening criteria. Manganese, aluminum, and
zinc in the slag leachate are expected to be relatively immobile in ground water and should not be readily
transported if released. Factors that influence the potential for these contaminants to be released and cause
impacts through the ground-water pathway are summarized in Exhibit 7-5.
None of the elemental phosphorus plants report the use of engineered controls (e.g., liners, leachate
collection systems) to limit infiltration through the piles.14 Consequently, EPA evaluated the hydrogeologic
setting of the plants to determine the potential for ground-water contamination from infiltration of
precipitation through the slag piles.
• Compared to the other elemental phosphorus plants, both the ML Pleasant and
Columbia plants are located in areas with relatively high to moderate potential for
contaminants to migrate into ground water (i.e., net recharge is relatively high
[25 cmjyr], but the aquifer is moderately deep [15 m]); both are in central Tennessee.
Although drinking water wells could exist at private residences located 700 and 200
meters downgradient of the ML Pleasant and Columbia plants, respectively, the
concentration of any released contaminants at these potential exposure points is likely
to be below levels of concern (considering the generally low concentrations measured
in the leachate).
11 In December 1989, the National Research Council published its Biological Effects of Ionizing Radiation or BEIR 5 Report that
offers new risk estimates from radiation exposure. These new risk factors are about twice the risk (actors used in the Pocatello and Soda
Springs study.
12 A "working level"is any combination of short-lived radon decay products in one liter of air that will result in the emission of alpha
panicles with a total energy of 130 billion electron-volts.
0 Environmental Protection Agency, 1983. Evaluation of Radon Sources and Phosphate Slag in Butte. Montana. EPA 520/6-83-026,
Washington, DC, June, 1983.
14 The Silver Bow and Columbia plants did not provide data on their stockpiles. In the absence of better data, EPA has assumed that
the piles at these facilities are not equipped with ground-water release controls.
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Chapter 7: Elemental Phosphorus Production 7-9
Exhibit 7-5
Summary of Release, Transport, and Exposure Potential
for Elemental Phosphorus Slag
Facility
Release, Transport, and Exposure
Potential for Elemental Phosphorus Slag
Proximity to
Sensitive Environments
SILVER BOW
Ground Water: Low net recharge (2.5 cm/yr) and large depth to
aquifer (27 m) restrict ground-water contamination potential;
potential drinking water exposure at residences within 800 m
downgradient.
Surface Water: Releases limited by low annual precipitation (34
cm/yr), gentle topographic slope (< 2%), and large distance (520m)
to nearest stream; no known uses of stream, but its small size (5.2
mgd) indicates little assimilation capacity and, therefore, possible
resource damage and aquatic ecological risks.
Air: Insufficient data on pile size and dust suppression practices to
support conclusion on release potential (although, facility mon-
itoring of air quality has not detected any exceedance of air quality
standards); average wind speeds up to 5.1 m/s and moderate
number of wet days (78 days/year) could lead to airborne dust;
potential exposures at residences as close as 640 m from the
facility; population within 1, 5, and 50 miles of the facility is 79; 608;
and 73,154, respectively.
No sensitive environ-
ments within 1.6 km
SODA SPRINGS
Ground Water: Releases from the slag pile may be limited by in-
situ clay beneath the pile, low net recharge (5 cm/yr), and large
depth to usable aquifer (27 m), but ground-water contamination that
may be attributable to slag management has occurred at the site;
potential drinking water exposures could occur at residences
located only 60 m downgradient of the facility.
Surface Water: Releases limited by stormwater runon/runoff
controls and low annual precipitation (35 cm/yr); a river (420 mgd)
is located 340 m from the facility, but it is not a source of drinking
water near the facility, although it does provide irrigation water 270
m downstream of the facility.
Air: Dust suppression used, but resident complaints indicate It may
not be effective; average wind speeds up to 3.5 m/s and moderate
number of wet days may (74 days/year) limit airborne dust; poten-
tial inhalation exposures at residences located adjacent to the
facility boundary, and food chain exposures through deposition of
particulate matter on agricultural fields in the vicinity of the facility;
population within 1. 5, and 50 miles of the facility is 369; 4,580; and
100,598, respectively.
Wetland within 1.6 km
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7-10 Chapter 7: Elemental Phosphorus Production
Exhibit 7-5 (cont'd)
Summary of Release, Transport, and Exposure Potential
for Elemental Phosphorus Slag
Facility
Release, Transport, and Exposure
Potential for Elemental Phosphorus Slag
Proximity to
Sensitive Environments
POCATELLO
Ground Water: Ground-water monitoring indicates contamination
possibly attributable to slag management; pile is unlined, but
leaching of slag contaminants to useable ground water may be
limited by low net recharge (1.2 cm/yr), great depth to aquifer
(61 m), and presence of an intermediate, perched water table above
the useable aquifer; potential drinking water exposures at residen-
ces located 300 m downgradient of the facility.
Surface Water: Releases limited by the large distance to the
Portneuf River (1400 m) and low annual precipitation (29 cm/yr); the
nearest stream (with a flow of 160 mgd) is used for fish hatching 2.4
km downstream from the facility.
Air: Potential releases are not controlled by dust suppression but
the number of wet days that could suppress dust is moderately
high (91 days/year); average wind speeds up to 6 m/s could lead to
wind blown dust, and air quality monitoring at the facility has
indicated past exceedance of the air quality standard for respirable
paniculate matter; potential inhalation exposures at residences as
close as 240 m from the facility, and food chain exposures through
deposition of paniculate matter on agricultural fields in the vicinity
of the facility; population within 1 mile is sparse (31 people) but
population within 5 and 50 miles is 35,869 and 166,100, respec-
tively.
No sensitive environ-
ments within 1.6 km
MT. PLEASANT
Ground Water: Pile underlain by in-situ clay, but high net re-
charge (25 cm/yr) and moderately deep aquifer (15 m) indicate high
to moderate potential for release; potential drinking water exposures
at residence located 700 m downgradient from facility.
Surface Water; Although stormwater runon/runoff controls are
employed, release potential is high because of high annual precipi-
tation (130 cm/yr), moderate topographic slope (up to 6 percent),
and short distance (120 m) to a nearby stream; no known uses of
the stream (which has a flow of 1.5 mgd), but its small size in-
dicates potential resource damage and ecological impacts resulting
from small assimilation capacity.
Air: Potential releases are not controlled by dust suppression, but
may be limited by the relatively small size of the piles (3 to 9 acres)
and the large number of wet days per year (105); average wind
speeds up to 4.6 m/s could, nevertheless, lead to windblown dust;
potential inhalation exposures at residences as close as 700 m from
the facility; population within 1, 50, and 50 miles is 145; 8,435; and
479,893, respectively.
No sensitive environ-
ments within 1.6 km
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Chapter 7: Elemental Phosphorus Production 7-11
Exhibit 7-5 (cont'd)
Summary of Release, Transport, and Exposure Potential
for Elemental Phosphorus Slag
Facility
Release, Transport, and Exposure
Potential for Elemental Phosphorus Slag
Proximity to
Sensitive Environments
COLUMBIA
Ground Water: No data on management controls at the pile, but
potential releases indicated by high net recharge (25 cm/yr) and
moderately deep aquifer (15 m below land surface); potential
drinking water exposures at residence located 210 m downgradient
of the facility.
Surface Water: No data on management controls at the pile, but
potential releases indicated by high amount of annual precipitation
(130 cm/yr) i 8nort distance to a nearby river (110m), and moderate
topographic slope (up to 6%); potential drinking water exposure
from a public water supply intake located 12 km downstream.
Air No data on management controls at the pile, but releases may
be limited by the large number of wet days per year (105); average
wind speeds up to 4.6 m/s could, nevertheless, lead to wind blown
dust; high inhalation exposure potential at a residence located 60 m
from the facility, and potential food chain exposures through
deposition of paniculate matter on agricultural fields in the vicinity
of the facility; population within 1, 5, and 50 miles is 418; 40,312;
and 935,013, respectively.
Located in area of karst
terrain; no other sensitive
environments within
1.6 km
• The potential for ground-water contamination caused by the elemental phosphorus slag
stockpiled at the Soda Springs (ID) plant appears to be relatively low based on the low
net recharge (5 cm/yr) and the large depth to the aquifer (24 m). However, if
contaminants reach the aquifer beneath this plant, they may pose human health risks
(via drinking water) at a residence located less than 100 meters downgradient.
• The potential for slag at the Pocatello and Silver Bow plants to cause ground-water
contamination appears lower because of even smaller net recharge (1.2 to 2.5 cm/year)
and larger depths to useable aquifers (27 to 61 meters). Releases to the useable aquifer
beneath the Pocatello plant are further limited by the presence of an intermediate,
perched aquifer above the useable aquifer. If releases were to occur, exposures at these
facilities may occur 300 meters downgradient of the Pocatello plant and 880 meters from
the Silver Bow plant Given the generally low concentrations of contaminants measured
in the slag leachate, however, the concentrations at these distance exposure points are
likely to be below levels of concern.
Ground-water monitoring results from Soda Springs, Pocatello, and Silver Bow show that releases to
ground water have occurred although the extent to which the slag piles have contributed to this contamination
is still under investigation. These facilities report that drinking water standards for fluoride, chloride,
manganese, sulfate, cadmium, and selenium have been exceeded in downgradient monitoring wells. Except
for chloride and selenium, these constituents have been detected in leach test analyses of elemental phosphorus
slag. Therefore, although the facilities state that ground-water contamination cannot definitely be attributed
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7-12 Chapter?: Elemental Phosphorus Production
to the stockpiles,15 EPA's waste characterization data suggest that the slag piles may have contributed to
observed ground-water contamination at these facilities.
Surface Water Release, Transport, and Exposure Potential
Constituents of potential concern in elemental phosphorus slag could, in theory, enter surface waters
by migration of slag leachate through ground water that discharges to surface water, or by direct overland
(storm water) run-off of dissolved or suspended slag materials. As discussed above, the following constituents
leach from the slag at levels that exceed the screening criteria: arsenic, chromium, manganese, aluminum,
fluoride, phosphorus, and phosphate. Other constituents present in the slag, such as cadmium, could also
present surface water threats if slag particles reach surface waters.
The potential for overland release of slag particles to surface waters is limited considerably by the
generally large size of the slag fragments. A small fraction of the slag material, however, may consist of
fragments that are small enough to be credible (i.e., approximately 0.01 cm in diameter or smaller). Because
the stockpiles have relatively steep slopes (from 13 to 27 percent), erosion from the piles could lead to the
overland How of small slag particles or dissolved slag contaminants to nearby surface waters. At the Mt.
Pleasant and Soda Springs plants, however, potential storm water run-off from the piles would be limited by
the run-off controls reported by these two facilities.
Three of the four elemental phosphorus facilities providing data report that they monitor water
quality in streams in the vicinity of the plant. Pocatello and Soda Springs report that ambient surface water
concentrations downstream of their plants have exceeded drinking water standards or ambient water quality
criteria (AWQC). Constituents detected in exceedance of standards or criteria include sulfate, cadmium,
chloride, selenium, and manganese. All of these constituents have been detected in the slag. Therefore, the
slag stockpiles cannot be ruled out as a possible source of this contamination based on EPA's waste
characterization data, although site-specific factors (discussed below) indicate that the slag piles are likely to
be only minor contributors to the contamination.
EPA's assessment of the potential for surface water releases and exposures at each facility depends
on the use of controls to limit storm water run-off, hydrologic characteristics of the plant locations, the
proximity of the plants to nearby streams, and the uses of these streams.
• The Columbia plant has moderate potential for releases of overland flow and ground-
water seepage to surface water because it receives a relatively large amount of
precipitation (Le., 130 cm/year), which can transport contaminants by recharge to
ground water or overland flow, and is located only 110 meters from Rutherford
Creek.16 However, the surface water damage potential is low, and not moderate or
high, because the nearby creek has a large capacity to assimilate contaminant inflows
(i.e., its annual average flow is 680 mgd).
• The Mt. Pleasant plant also has a moderate surface water release potential. Although
this plant is located 120 meters from a small stream (Big Bigby Creek) with a flow of
1.5 mgd, overland releases of storm water run-off from its slag pile would be limited by
run-off controls. As discussed above, this facility has a relatively high ground-water
release potential. Therefore, seepage of contaminated ground water from the pile to
the nearby stream may present aquatic ecological risks in the stream and/or restrict uses
of this surface water resource (if it is large enough to be used). No health risks to
existing human populations are expected because there are no intakes for drinking water
supplies within 24 km (15 miles) of the plant.
15 For example, Monsanto attributes ground-water contamination at the Soda Springs facility to the pre-1984 use of unlined ponds for
managing process wastewater. Refer to the case study findings later in this section for a discussion of the ground-water contamination
at the Pocatello plant.
16 Occidental did not provide information on the use of nin-on/run-off controls at the slag pile, therefore, EPA assumes that releases
from this unit are not limited by engineered controls.
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Chapter 7: Elemental Phosphorus Production 7-13
• Slag piles at the western plants (Silver Bow, Pocatello, and Soda Springs) have relatively
low surface water contamination potential because of large distances to nearby surface
waters (i.e., 340 to 1,400 meters), low levels of precipitation (i.e., 29 to 35 cm/year), and
relatively low ground-water release potential. The release potential at the Soda Springs
plant is further limited by storm water run-off controls employed at the slag pile. If
releases to these surface waters did occur, the potential for resource damage and aquatic
ecological risks is greatest at the Silver Bow plant because the Silver Bow Creek has a
small assimilative capacity (less than 5.2 mgd). If releases from the Pocatello plant
reach the Portneuf River and are not sufficiently diluted, they could endanger aquatic
life in the river, harm current use of the river as a fish hatchery, and restrict potential
future uses of the river. Releases from slag piles at the Soda Springs plant could
jeopardize consumptive uses of Little Spring Creek and Bear River (such as the current
use for irrigation) and endanger the streams' aquatic life, if contaminants are not
sufficiently diluted by the water's flow.
In summary, although surface water releases may be somewhat limited by the physical form of the slag
and the use of storm water run-off controls at two facilities (Mt. Pleasant and Soda Springs), surface water
releases of slag contaminants may occur by the seepage of leachate to ground water that discharges to surface
water or by the overland flow of small fragments of slag. At the two facilities located in Tennessee (Mt.
Pleasant and Columbia), surface water releases are more likely than at the facilities in Idaho and Montana
(Pocatello, Soda Springs, and Silver Bow) because of the greater amount of precipitation (which leads to
overland flow and ground-water discharge) and their close proximity to streams. Only slag at the Columbia
plant poses a potential human health threat via the surface water pathway at present, and even this threat is
very minor considering the large assimilative capacity of Rutherford Creek. The other facilities conceivably
may pose aquatic ecological threats and/or restrict current and potential future uses of the streams, if
contaminants entering these waters are not sufficiently diluted.
Air Release, Transport, and Exposure Potential
Because all of the constituents of concern in elemental phosphorus slag are nonvolatile, slag
contaminants can be released to air only in the form of dust particles. As discussed above, uranium-238,
cadmium, and chromium are present in the slag in concentrations that exceed the inhalation screening criteria.
EPA's Office of Air and Radiation recently promulgated regulations governing the airborne emissions of
radionuclides from elemental phosphorus plants (54 FR 51654, December 15,1989). However, these standards
apply only to airborne releases of radionuclides from calciners and nodulizing kilns, not to slag management
units or operations.
Factors that affect the potential for airborne releases - by either wind erosion or vehicular traffic
disturbance - include the particle size and moisture content of the slag, the area of the stockpiles, wind
speeds, and the use of dust suppression methods.
Release of elemental phosphorus slag particles to the air is limited in part by the large particle size
and glassy form of the slag. In general, particles that are <. 100 micrometers (/im) in diameter are wind
suspendable and transportable. Within this range, however, only particles that are <. 30 fim in diameter can
be transported for considerable distances downwind, and only particles that are <. 10 pm in diameter are
respirable. The slag generally consists of particles larger than 100 fim in diameter (i.e., the maximum particle
size that is suspendable and transportable), and therefore, the majority of the slag is not suspendable,
transportable, or respirable. It is likely that only a small fraction of the slag will be weathered and aged into
smaller particles that can be suspended in air, and after the small, near-surface particles are depleted, airborne
emissions would be expected to decline to low levels. Nevertheless, considering the large exposed surface area
of the slag stockpiles and concerns about dusting that have been expressed by EPA Regional personnel and
local residents, the Agency acknowledges that large quantities of dust from elemental phosporous slag piles
may be blown into the air during high winds.
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7-14 Chapter 7: Elemental Phosphorus Production
Other, site-specific factors that influence the potential for dusting and subsequent exposures are
described below:
• Potential dust releases from the Columbia plant may be limited by the large number
(105 days/year) of days with precipitation. However, this plant has a relatively high air
pathway exposure potential because the nearest residence is located only 46 meters away
from the plant, and the population in the vicinity of the facility is relatively dense (i.e.,
population within 1.6, 8, and 80 km (1, 5, and 50 miles) is 418; 40,312; and 935,013
people, respectively).
• At the Pocatello plant, high dust suspension potential is indicated by past exceedances
of the air quality standard for respirable paniculate matter and high wind speeds (an
average of up to 6 m/s). The source of this dust is not specified in the available data.
The number of days with precipitation that could suppress dust is moderate (91
days/year). Air pathway exposures could occur at residences located 240 meters from
this plant. The population within 1.6 km (one mile) of the facility is relatively sparse
(31 people), but the population within 8 and 80 km (5 and 50 miles) is 35,900 and
166,100 people, respectively.
• Although dust suppression is practiced to control airborne releases from the Soda
Springs slag pile, complaints about windblown dust from the stack indicate that this
control may not be effective. Potential exposures could occur at a residence located
directly adjacent to the facility boundary near the stack, and the population within 1.6,
8, and 80 km (1, 5, and 50 miles) of the facility is relatively dense (i.e., 369; 4,600; and
100,600 people, respectively).
• Silver Bow and Mt. Pleasant have relatively low air pathway release and exposure
potential because of more moderate typical winds and the greater distance to nearby
residences (640 to 805 meters). The potential for release may be comparatively greater
at the Silver Bow facility because of the smaller number of days with precipitation that
could suppress dust (78 days/year), and the higher average wind speeds (5.1 m/s). The
potential for exposure, on the other hand, is greater at the ML Pleasant facility because
of the dense population around the facility (population within 1.6, 8, and 80 km (1, 5,
and 50 miles) is 145; 8,400; and 479,900 people, respectively).
Three of the facilities - Soda Springs, Pocatello, and Columbia ~ are located in areas with significant
agricultural land use. In addition to potential inhalation risks, airborne releases of slag contaminants at these
facilities could enter the human food chain through the deposition of suspended slag particles onto crops.
Based on these findings, EPA acknowledges the need for further study and possible control of windblown dust
from elemental phosphorus slag piles, especially at the Soda Springs, Pocatello, and Columbia facilities, both
during the operating life of the piles and after closure.
Proximity to Sensitive Environments
As summarized in Exhibit 7-5, only the Soda Springs and Columbia plants are located in environments
that are vulnerable to contaminant releases or environments with high resource value that may warrant special
consideration.
The Soda Springs facility is located within one mile of a wetland area (defined here to
include swamps, marshes, bogs, and other similar areas). Wetlands are commonly
entitled to special protection because they provide habitat for many forms of wildlife,
purify natural waters, provide flood and storm damage protection, and afford a number
of other benefits. Although the potential for ground-water and surface water releases
from the slag pile at this facility is low, any such releases could adversely affect the
function and value of this wetland area.
The Columbia facility is located in an area of karst terrain (i.e., irregular topography
characterized by solution features in soluble rock such as limestone). Releases to
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Chapter 7: Elemental Phosphorus Production 7-15
ground water in karst terrain can pose ground-water and surface water health risks and
ecological risks because of the limited dilution potential of the conduit flow that is
characteristic of ground-water movement in such areas (i.e., solution cavities that may
exist in the bedrock at this site could permit any ground-water contamination
originating from the slag pile to migrate in a largely unattenuated and undiluted
fashion).
Risk Modeling
Based upon the evaluation of intrinsic hazard, the descriptive analysis of factors that influence risk
presented above, and upon a comprehensive review of information on documented damage cases (presented
in the next section), EPA has concluded that the ground-water and surface water risks posed by elemental
phosphorus furnace slag are relatively low when the slag is managed on-site according to current practice.
However, windblown dust at three facilities may pose a moderate risk via the inhalation and ingestion
pathways. This overall conclusion is supported by the generally low to moderate risk estimates predicted by
the Agency's modeling of other mineral processing wastes that appear to pose a substantially greater risk when
managed in on-site stockpiles. Therefore, the Agency has not conducted a quantitative risk modeling exercise
to examine the hazards of on-site slag management in greater detail. The Agency recognizes that the radiation
risks associated with the off-site use of elemental phosphorus slag are high. EPA did not attempt to model
these risks, however, because the recently completed study in Pocatello and Soda Springs provides definitive
risk estimates based on actual field observations.
7.3.2 Damage Cases
State and EPA regional files were reviewed in an effort to document the environmental performance
of slag waste management practices at the five elemental phosphorus facilities. The file review process was
combined with interviews with state and EPA regional regulatory staff to develop a complete and accurate
assessment of the extent to which slag has resulted in cases of documented danger to human health or the
environment.
These sources did not reveal any sites with documented environmental damage that was clearly the
result of management practices at units containing elemental phosphorus slag. However, concentrations of
some heavy metals in ground water in excess of primary drinking water standards were documented, along with
abandonment of an off-site drinking water well due to heavy metal contamination at the FMC facility in
Pocatello.17 The information reviewed indicates that unlined waste ponds appeared to be the source of the
contamination at this facility. These unlined ponds, which have been replaced by lined ponds, contained a
variety of wastewaters, including "phossy water, precipitator dust slurry, calciner scrubber water, slag cooling
water, and general site run-off." None of these waste management units are known to contain slag; however,
the slag cooling water pond, and possibly the "rainwater pond" as well, are related to slag management.
Sampling of the ponds during a Superfund Site Investigation indicated that concentrations of some
constituents in the slag cooling water pond were more than 100 times the primary drinking water
standard.18-19
17 Ground-water contamination in the area of the facility and the adjacent J. R. Simplot phosphoric acid plant has led to the area being
proposed for the Superfund National Priority List (see Eastern Michaud Flats Contamination).
18 Ecology & Environment, 1988. Site Inspection Report for FMC/Simplot, Pocatello, Idaho. TDD F10-8702-09110. April, 1988.
19 Ecology & Environment, 1988. Special Study Waste Analysis for Eastern Michaud Flats Groundwater Contamination. November,
1988.
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7-16 Chapter 7: Elemental Phosphorus Production
7.3.3 Findings Concerning the Hazards of Elemental Phosphorus Slag
Based upon the detailed examination of the intrinsic hazards of elemental phosphorus slag, the
management practices that are applied to this waste, the environmental settings in which the generators of the
material are situated, and the documented environmental damages that have been described above, EPA
concludes that these wastes pose a low to moderate risk to human health and the environment as currently
managed on-site, but a high risk when used off-site in construction due to the radioactivity of the material.
Available data on the composition of elemental phosphorus slag show that the slag contains nine
nonradioactive contaminants in concentrations that exceed the risk screening criteria, although only four
constituents exceed the criteria by more than a factor of 10. In addition, the slag contains elevated
concentrations of uranium-238 and its decay products that may pose a significant radiation hazard if the slag
is not properly controlled. Based on available sampling data and professional judgment, however, EPA does
not believe that the slag exhibits any of the characteristics of hazardous waste (ignitability, corrosivity,
reactivity, or EP toricity).
Elemental phosphorus slag has been widely used for many years for a variety of purposes, many of
which can cause increased radiation exposure to people living or working near the slag-bearing materials.
Recently completed EPA research shows that significant cancer risks have been caused by the off-site use of
elemental phosphorus slag in street paving and home foundations in Soda Springs and Pocatello, ID.
According to these research findings, average lifetime cancer risks caused by exposures to direct gamma
radiation from these materials range from 4x10"* in Pocatello to IxlO"3 in Soda Springs; lifetime cancer risks
of maximally exposed individuals in these two cities can be as high as 6xlO"3. EPA notes, however, that the
cancer risks in these two cities may actually be a factor of two higher. Because of these high risks, the State
of Idaho banned the use of elemental phosphorus slag in all occupied structures in 1977, but slag can still be
used as an aggregate in road construction in Idaho. Any future uses of elemental phosphorus slag in Idaho
and elsewhere need to be closely evaluated and controlled to prevent high radiation exposures.
Based on a review of existing management practices and release/exposure conditions, EPA believes
that the current practices of managing the slag at the five active elemental phosphorus facilities generally pose
a low risk via the ground-water and surface water exposure pathways. Although low levels of ground-water
recharge and large depths to ground water at three of the facilities appear to limit the potential for slag
contaminants to migrate into ground water, contamination that may be attributable to the slag has been
observed. At the other two facilities, releases of constituents are not controlled by favorable hydrogeologic
conditions, so migration of contaminants into ground water is possible. This migration, however, is not
expected to pose significant current risks at any of the sites because of the relatively low concentrations of
potentially harmful constituents in laboratory leachate of the slag. The generally large size of slag particles
limits the potential for water erosion to transport slag contaminants to surface water exposure points. Surface
water contamination potential is also limited by the relatively large distances from three of the facilities to the
nearest surface waters. The absence of documented cases of ground-water and surface water damage that
clearly results from elemental phosphorus slag management further supports the finding that this waste, when
managed on-site, poses a relatively low ground-water and surface water risk.
However, EPA believes that current slag management at three facilities poses a moderate risk via the
air exposure pathway. Although the generally large size of slag particles tends to limit wind erosion, large
quantities of dust blowing from the slag pile at one facility has been alleged by nearby residents and the slag
pile at another facility is recognized as a potential contributor to high levels of airborne particulates.
Exposures of nearby residents to any windblown contaminants at these two and one other facility are possible,
and EPA acknowledges the need for further study and possible control of windblown dust at these sites. Air
pathway exposures at the other two facilities are, at present, less likely because of the large distance to
potential receptors.
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Chapter 7: Elemental Phosphorus Production 7-17
7.4 Existing Federal and State Waste Management Controls
7.4.1 Federal Regulation
The Stauffer Chemical Company facility in Silver Bow, Montana, which generates elemental
phosphorus slag, is located on Federal land (in a National forest), and is therefore subject to the regulations
set forth by the U.S. Department of Agriculture's Forest Service. The regulations governing the use of the
surface of National Forest Service lands (36 CFR 228 Subpart A) are intended to "minimize adverse
environmental impacts...." They require that operators file a "notice of intent to operate." If deemed
necessary, the operator may be required to submit a proposed plan of operations in order to ensure minimal
adverse environmental impact.
Section 3001(b)(3)(iii) of RCRA, which was added by the Solid W-iste Disposal Act Amendments of
1980 (Oct. 21,1980), provides EPA with the authority to develop regulations "to prevent radiation exposure
which presents an unreasonable risk to human health from the use in construction or land reclamation (with
or without revegetation) of (I) solid waste from the extraction, beneficiation, and processing of phosphate rock
or (II) overburden from the mining of uranium ore."
The National Environmental Policy Act (NEPA) may also be applicable to this facility. NEPA may
require that an Environmental Impact Statement (EIS), which establishes the framework by which EPA and
the Council on Environmental Quality may impose environmental protection requirements (40 CFR Parts
1500-1508), be prepared for any ore processing activities on Federal lands.
EPA is unaware of any other specific management control or pollutant release requirements that
apply specifically to elemental phosphorus slag (the October, 1989 National Emissions Standard for Hazardous
Air Pollutants (NESHAP) controlling radionuclide emissions from elemental phosphorus plants only addresses
stack emissions, not slag or other potential radionuclide sources (54 FR 51671)).
In the State of Idaho, which has no EPA-approved NPDES program, EPA would utilize State water
quality standards when writing NPDES permits.
7.4.2 State Regulation
The five facilities generating elemental phosphorus furnace slag are located in three states, Idaho,
Tennessee, and Montana. Two facilities are located in both Idaho and Tennessee, while a single facility is
located in Montana. All three states were selected for regulatory review for the purposes of this report (see
Chapter 2 for a discussion of the methodology used to select states for detailed regulatory study).
All three states with elemental phosphorus facilities exclude mineral processing wastes, including the
furnace slag generated at these facilities, from hazardous waste regulation. Of the three states, only lennessee
has solid waste regulatory provisions that apply to elemental phosphorus furnace slag. Tennessee's solid waste
regulations include provisions for industrial solid waste landfills, which include landfills used to dispose of
furnace slag. The state's implementation of its solid waste regulations, however, has focused on municipal
solid waste landfills; the two elemental phosphorus facilities in Tennessee both have permits for on-site
industrial landfills, but are not currently subject to strict design or operating criteria. Tennessee recently
amended its regulations and appears to be preparing to regulate mineral processing wastes more
comprehensively. Under the new regulations, the two elemental phosphorus facilities could be required to
undertake various management practices, such as the submission of design drawings for approval, the
preparation of contouring plans, the installation of liners and leachate collection systems, and conditional
ground-water monitoring. The new regulations also include provisions for financial assurance for closure and
30 years of post-closure care.
In contrast to Tennessee's solid waste regulatory efforts, neither Idaho nor Montana currently
regulates elemental phosphorus slag as solid waste. Idaho does not require solid waste permits for the disposal
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7-18 Chapter 7: Elemental Phosphorus Production
of mineral processing wastes, including elemental phosphorus furnace slag. Montana classifies mineral
processing wastes as solid wastes, but does not regulate these wastes if they are disposed of on-site, as happens
at the single Montana elemental phosphorus facility, and the wastes do not pose a nuisance or health hazard.
Of all three states, only Idaho specifically prohibits the use of elemental phosphorus furnace slag in
construction materials for habitable structures.
Water and air quality regulations vary in their applicability to mineral processing wastes across the
three states, but generally follow the pattern set by current solid waste regulation. Tennessee's water quality
regulations require that no sewage, industrial waste, or other wastes may cause a violation of state water
quality standards. Both facilities in Tennessee maintain state-administered NPDES permits. Idaho's
regulations make no mention specifically of mineral processing wastes but require all non-sewage discharges
to be treated in order to comply with federal water quality standards. According to state officials in Montana,
run-off from elemental phosphorus slag piles does not require a NPDES permit and is not addressed
otherwise. Finally, although mineral processing facilities in all three states must obtain air permits in order
to operate, there are no specific regulations addressing fugitive dust suppression for elemental phosphorus
furnace slag in any of the three states.
In summary, all three states with elemental phosphorus facilities exclude from hazardous waste
regulation the furnace slag generated at those facilities. Moreover, two of the states, Idaho and Montana, are
effectively not requiring environmental controls for on-site disposal of these slags under their solid waste
regulations. Tennessee's solid waste regulations do include provisions for industrial solid wastes. Although
these regulations have not been implemented aggressively to date, the state recently revised its solid waste
rules and appears to be preparing to regulate furnace slag and other mineral processing wastes more
comprehensively. Tennessee and Idaho have water quality provisions that could apply to furnace slag waste
management activities, though only the two facilities in Tennessee maintain NPDES permits for those
activities. Montana does not require a NPDES permit for run-off discharges from its facility's furnace slag
waste piles. Finally, none of the three states have fugitive dust suppression provisions for furnace slag disposal
units in their air regulations.
7.5 Waste Management Alternatives and Potential Utilization
Waste Management Alternatives
By waste management alternatives, EPA is referring to both ways of actually disposing of the waste
(e.g., landfills and waste piles), and methods of minimising the amount of waste generated. Vfoste
minimization generally encompasses any source reduction or recycling that results in either the reduction of
total volume or toricity of hazardous waste. Source reduction is a reduction of waste generation at the source,
usually within a process. Source reduction can include process modifications, feedstock (raw material)
substitution, housekeeping and management practices, and increases in efficiency of machinery and equipment.
Source reduction includes any activity that reduces the amount of waste that exits a process. Recycling refers
to the use or reuse of a waste as an effective substitute for a commercial product, or as an ingredient or
feedstock in an industrial process.
Disposal Alternatives
Of the four facilities that did not designate the relevant portions of their 1989 SWMPF Surveys as
confidential, none sends its slag off-site for disposal. While it is conceivable that some, or even all, of the
facilities could do so, the cost of transporting large volumes of phosphorus slag, and the rising cost of
commercial landfill capacity make it unlikely that elemental phosphorus processors will utilize off-site disposal
capacity if on-site capacity is available and the regulatory status of the material does not change. Situations
that could increase the likelihood of off-site disposal are the classification of elemental phosphorus slag as
hazardous waste, a limited amount of area for on-site disposal, and reduced slag generation rates. Increased
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Chapter 7: Elemental Phosphorus Production 7-19
need for disposal in general (either on-site or off-site) would result from increased restrictions on uses of the
slag.
Waste Minimization
Opportunities for waste minimization may include raw material substitutions, though these
opportunities are somewhat limited because of the transportation costs involved in using ores or concentrates
produced in other regions or countries. Consequently, raw materials substitution generally takes the form of
improving the separation of the value from the raw ore during beneficiation, so that the furnace operations
would begin with a higher grade of ore concentrate. Processing a feedstock with a higher concentration of
phosphorus results in decreased slag generation, although presumably increasing the generation of related
beneficiation wastes. Other source reduction opportunities may involve processing modifications to increase
the efficiency of phosphorus recovery during the furnace operation.
Waste Utilization
Utilization of mineral processing "wastes" can be a viable alternative to disposal. In 1988, for example,
Occidental's Columbia plant reported selling all of its slag, while three other facilities are known to have sold
some portion of their slag for off-site use (specific data are confidential). Only the Silver Bow facility reported
disposing all of its slag rather than selling it as a product. However, there may be risks associated with such
practices, as indicated by the EPA studies in Idaho.
Option 1: Utilization as a Highway Construction Aggregate
Description. Phosphorus slag is used as an aggregate in asphalt manufacturing. It normally requires
crushing and sizing by slag processing contractors to meet specific aggregate size requirements before it can
be mixed with the asphalt
Current and Potential Use. Elemental phosphorus slag has been used extensively in highway
construction for many years in Idaho, Montana, and Tennessee.20 Its hardness, uniformity, and inert
chemical composition make it an excellent aggregate material for construction purposes and it is specified as
a skid resistant coarse aggregate in bituminous wearing surfaces. The material is used in various phases of
highway construction, including crushed base, crushed aggregate for asphalt (i.e., bituminous paving and seal
coats), and as casting material for highway structures. The Occidental facility in Tennessee was able to sell
nearly all of the slag it produced in 1988, a significant portion of which is believed to have been used for
highway construction.21 The facility indicated that they could sell even more of the material if more was
produced. The demand for phosphorus slag is high in Tennessee because supplies of natural aggregate are
sparse. As noted above, however, recent studies in Idaho indicate that such uses contribute significantly to
gamma radiation exposure of the local populations.
Although the Stauffer Chemical Company in Montana reportedly sold none of the slag that it
generated in 1988, phosphorus slag is known to have widespread usage in road construction in both Idaho and
Montana.22 Demand for the slag as an aggregate in Idaho and Montana is expected to be lower than the
demand in Tennessee because of the locations of the facilities with respect to market areas and the problem
of residual radioactivity in the western ores.
20 Collins, RJ. and R.H. Miller, Availability of Mining Wastes and Their Potential for Uie as Highway Material - Volume I:
Classification and Technical and Environmenul Analysis. FHWA-RD-76-106, prepared for Federal Highway Administration, May 1976,
p. 168.
21 Private communication with Eddie Floyd, Occidental Chemical Co., April 11, 1990.
22 Collins, R J. and R.H. Miller,
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7-20 Chapter 7: Elemental Phosphorus Production
The potential of phosphorus slag as a construction aggregate depends, at least partly, on its ability
to successfully compete in the market place with the other sources of aggregates. The effect of facility location
on its competitiveness in the market is discussed below, and competitive pricing is discussed in the section on
feasibility.
Access to Markets. Because aggregate is a relatively low value, high bulk commodity,
transportation costs are a key factor in establishing and maintaining markets for this product. Accordingly,
producers must be located in relatively close proximity to product markets to be price competitive and,
therefore, economically viable, or aggregate must be in short supply to justify haul distances greater than 80
to 160 km (50 to 100 miles).23 The two facilities in Idaho are both located approximately 480 km from Salt
Lake City, 320 km from Twin Falls, and less than 400 km from Pocatello. The two facilities are also located
within 400 km of an area in central Montana that has an aggregate shortage. The Stauffer plant in Silver Bow,
Montana is located within 16 km of Butte, within 160 km of Helena and Missoula, and less than 240 km from
the area in central Montana with an aggregate shortage. The two facilities in Tennessee are both located
within 160 km of Nashville, Huntsville, and Chattanooga, and within 160 km of an area in eastern Tennessee
with an aggregate shortage. The Tennessee facilities are also located approximately 480 km from Memphis
and an aggregate shortage area in western Tennessee. Therefore, all of the facilities have potential markets
for their slag as an aggregate material.
Factors Relevant to Regulatory Status. The primary environmental concern for elemental
phosphorus slag stems from the radionuclides found in the slag. The slag is typically composed of
approximately 44 percent calcium, or lime (CaO), 44 percent silica (SiO^, 6 percent alumina (A12O3), 1
percent iron oxide (F^C^); it also contains most of the nonvolatile radionuclides originally present in the ore.
Radium-226 levels in elemental phosphorus slags from Idaho and Montana have been observed to range from
4 to 32 pCi/g, whereas the concentrations in slag from the two facilities in Tennessee have been measured at
3.2 to 27 pCi/g.24-25 Concentrations of uranium and thorium in elemental phosphorus slag range from 23
to 50 pCi/g in Montana and Idaho, and from 2.4 to 45 pCi/g in Tennessee.26-27
Due to concerns over radiation exposure, the State of Idaho has prohibited the use of phosphorus
slag in the construction of habitable structures since 1977,28 though slag is still used as an aggregate in road
construction in Idaho. Exposure rates of 100 microroentgens per hour (>R/h) have been measured at outdoor
slag piles at the FMC plant in Pocatello, Idaho,29 as compared to natural background radiation in the same
area of 9 /iR/h.30 In addition, significant gamma radiation exposures associated with a variety of slag
construction uses have been identified (see discussion in Section 73.1).
23 Ibid, p. 239.
24 Stula, R.T., eL al., Airborne Emission Control Technology for the Elemental Phosphorus Industry—Final Report to the
Environmental Protection Agency, prepared for US. Environmental Protection Agency Under Contract Number 68-01-6429, January 26,
1984, pp. 3-38, 3-59, 3-75, 3-129, and 3-162. Data provided in this report for facilities that have been dosed are not included in the
discussion here.
25 Company responses to EPA's National Survey; see footnote 2.
26 Stula, et aL, og. cjt., pp. 3-38, 3-59, 3-76, 3-129, and 3-162.
27 Company responses to EPA's National Survey; see footnote 2.
28 Baker, E.G., H.D. Freeman, and J.N. Hartley, Idaho Radionuclide Exposure Study-Literature Review, prepared for U.S.
Environmental Protection Agency. Office of Radiation Programs, under a related services contract with the US. Department of Energy,
Contract DE-AC06-76RLO 1830, October, 1987, p. 4,6
29 Radiological Surveys of Idaho Phosphate Ore Processing - The Thermal Process Plant, prepared for the U.S. Environmental
Protection Agency, Office of Radiation, Los Vegas Facility, November, 1977, pp. 8-9.
30 Ibid.
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Chapter 7: Elemental Phosphorus Production 7-21
While there are a number of constituents that can leach from elemental phosphorus slag, the
entrainment of the slag within the asphalt matrix should significantly reduce the potential for leaching. In
addition, the slag itself is a glass-like material containing the radionuclides in a vitrified matrix, which
significantly limits leaching potential in the original material. However, if the asphalt were to exhibit any
undesirable characteristics (e.g., significant leaching of radionuclides), the environmental impacts could be
extensive because the slag would be widely distributed.
The slag particles that are too small to be used as aggregate require disposal, unless they can be
utilized in some other way (e.g., as a substitute for portland cement, as is discussed later). If disposed, there
is a greater potential for leaching, since the small particle size of the slag fines will cause them to have a
greater surface area than the same quantity of unprocessed phosphorus slag.
Feasibility. The use of elemental phosphorus slag in highway construction is technically and
economically feasible, as evidenced by its continued use for this purpose. EPA has not identified any existing
regulatory constraints on the use of phosphorus slag in highway construction.
Future slag utilization as an aggregate will depend on the price of competing aggregate materials, the
cost of retrieving and crushing and screening (i.e., sizing) the slag, the distance the slag must be transported
to its point of use, regulatory limitations, and its social acceptability (i.e., concerns over radiation risks).
Other Options
There are a number of other potential ways to utilize phosphorus slag which are mentioned in the
literature, but for which there is little information beyond the fact that an alternative use of the slag has been
employed. In the following paragraphs, EPA discusses and comments on each alternative to the extent
permitted by the available information.
Use In Making Portland Cement and Concrete. Phosphorus slag has been used as a substitute
for portland cement rock in the manufacturing of portland cement.31 In addition, the University of
Tennessee has evaluated several sources of phosphorus slag for use as fine aggregates. As a result of this
study, phosphorus slag produced by Monsanto at Columbia, Tennessee, were found to be acceptable (in terms
of materials performance) for use in portland cement concrete.32 The slag has been used as an aggregate
for portland cement concrete in making constructions blocks, and pouring driveways, patios, and drainage
ditches.33 However, such uses have been prohibited in some areas and significant gamma radiation exposure
from such uses has been documented (see Section 7.3.1).
Radionuclide emission testing of the use of phosphorus slag as a construction aggregate led to a 1977
ban by the State of Idaho on the use of the material in construction of habitable structures.34 However, the
radionuclide properties of phosphorus slag vary significantly by the location of the ore deposits. Therefore,
the feasibility and acceptability of using phosphorus slag as an aggregate for portland cement concrete will also
depend on the origin of the slag.
Raw Material for Making Ceramic Tile. Phosphorus slag was found to have a composition
corresponding to a pseudo-wollastonite known as the alpha form of natural wollastonite, a mineral that is
mined in large tonnages to supply the ceramic tile industry. Research has demonstrated that phosphorus slag
31 Kirk Othmer, Encyclopedia of Chemical Technology, Third Edition, Volume 5, Wiley-Interscience Publications, John Wiley and Sons,
p. 187.
32 Collins, RJ. and R.H. Miller, o£.tit., p. 197.
33 Stula, et. al., oj>. tit., pp. 3-4.
34 Baker, Freeman, and Hartley, og. cjt.
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7-22 Chapter 7: Elemental Phosphorus Production
would be suitable (in terms of materials performance) for use in production of high-quality tile products.
When properly ground and treated magnetically to remove iron constituents (magnetite), the slag comprised
a raw material suitable for forming, dry pressing, sintering, and glazing to yield high quality floor and wall tile.
The estimated production cost compared favorably with the cost of commercially produced wall tile.
Railroad Ballast and General Construction Uses. Elemental phosphorus slag is currently used
as railroad ballast and as stabilization material for stockyards.35 In Florida, where the use of elemental
phosphorus slag in habitable structures has not been prohibited, slag has been used on roofing shingles and
in septic tank fields. It has also been used in the manufacturing of rockwool insulation.36
Using phosphorus slag as railroad ballast or in general construction use does not change the chemical
or physical characteristics of the slag, although it may have some effect on the ability of the slag's potentially
hazardous constituents to leach and contaminate ground and/or surface waters. The concentration of radium-
226 in slag pile rainwater runoff at the Pocatello plant has been observed to be 0.70 pCi/g in the liquid fraction
and 14 pCi/L in the suspended solids fraction. When the slag is used as railroad ballast, the surface area
available for leaching may be increased, though the actual rate of leaching will depend on environmental
settings, and could therefore vary considerably.
7.6 Cost and Economic Impacts
Because the available data indicated that elemental phosphorus slag does not exhibit any of the
characteristics of hazardous waste, the issue of how waste management costs might change if Subtitle C
regulatory requirements were applied and what impacts such costs might impose upon affected facilities is
moot Accordingly, EPA has not estimated costs associated with removing elemental phosphorus slag from
the Mining Waste Exclusion, which EPA's data indicate would have no practical effect on waste management
costs.
EPA does have significant concerns about certain off-site uses of elemental phosphorus slag because
of the relatively high residual radioactivity contained within this material. EPA has not, however, calculated
the costs or impacts associated with limiting or prohibiting sales of elemental phosphorus slag for particular
off-site uses for this report
7.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For the
special waste generated by this commodity sector (elemental phosphorus slag), these categories address the
following three major topics: (1) the potential for and documented danger to human health and the
environment; (2) the need for and desirability of additional regulation; and (3) the costs and impacts of
potential Subtitle C regulation.
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of elemental phosphorus slag is moderate to high in comparison to the other
mineral processing wastes studied in this report. The slag does not exhibit any of the four characteristics of
hazardous waste and contains only four constituents that exceed one or more of the screening criteria used
in this analysis by more than a factor 10. However, elemental phosphorus slag also contains elevated
35 Baker, Freeman, and Hartley, o£.dl., pp.
34 Stula, et. al., ogxil., pp. 3-4.
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Chapter 7: Elemental Phosphorus Production 7-23
concentrations of uranium-238 and its decay products that may pose a significant radiation hazard if the slag
is not properly controlled.
Based on a review of existing management practices and release/exposure conditions, EPA believes
that the current on-site slag management practices at the five active elemental phosphorus facilities generally
pose a low risk via the ground-water and surface water exposure pathways. Low levels of ground-water
recharge and large depths to ground water at three of the facilities appear to limit the potential for slag to
cause ground-water contamination, but contamination that may be attributable to the slag has been observed.
At the other two facilities, releases of constituents are not controlled by favorable hydrogeologic conditions,
so migration of contaminants into ground water is possible. This migration, however, is not expected to pose
significant risks at any of the sites because of the relatively low concentrations of potentially harmful
constituents in slag leachate, as determined by laboratory tests. The generally large size of slag panicles limits
the potential for stormwater erosion to transport slag contaminants to surface water exposure points. Surface
water contamination potential is also limited by the relatively large distances from three of the facilities to the
nearest surface waters. The absence of documented cases of ground-water and surface water damage that
clearly results from elemental phosphorus slag disposal further supports the finding that on-site disposal of
this waste poses a relatively low risk via these pathways. However, EPA believes that on-site slag management
at three facilities poses a moderate risk via the air exposure pathway. Although the generally large size of slag
particles also tends to limit wind erosion, dust from the slag piles may be blown into the air and lead to
significant exposures of residents near three of the plants. No people live near the other two plants and
significant exposures through the air pathway are not likely at these plants.
In contrast, EPA studies have shown that use of elemental phosphorus slag in residential building and
municipal (e.g., road, sidewalk) construction applications has resulted in unacceptable human exposure to
gamma radiation and resultant high incremental cancer risk. According to recent EPA research findings,
average lifetime cancer risks caused by exposures to direct gamma radiation from elemental phosphorus slag
used in street paving and home foundations in Soda Springs and Pocatello, ID range from 4xlO~4 to IxlO"3;
lifetime cancer risks of maximally exposed individuals in the two cities that were studied can be as high as
6xlO'3.37 EPA notes with interest that use of slag in inhabited structures has been prohibited in the State
of Idaho for more than ten years, and believes that the radiation risks associated with the off-site use of
elemental phosphorus slag should also be addressed on the national level.
Likelihood That Existing Risks/Impacts Will Continue in the
Absence of Subtitle C Regulation
The relatively low to moderate risk from the on-site management of elemental phosphorus slag is
expected to continue in the future in the absence of Subtitle C regulation given current waste management
practices and environmental conditions at the five active facilities. The characteristics of this waste are
unlikely to change in the future, and although this analysis is limited to the five sites at which the waste is
currently managed, EPA believes that it is unlikely, based on overall market conditions and the marginal
profitability of the industry, that elemental phosphorus production will expand to other locations. Therefore,
the Agency believes that the findings and conclusions of this study reflect conditions at all locations at which
elemental phosphorus slag is expected to be managed on-site in the future.
In the absence of more stringent federal regulation of on-site management of elemental phosphorus
slag, state regulation is expected to continue to control risks to a limited extent Furnace slag from elemental
phosphorus production is generated in three states, Tennessee, Montana, and Idaho, all of which exempt this
waste from hazardous waste regulation. Of these three states, only Tennessee addresses furnace slag under
its solid waste regulations. Tennessee, however, has historically focused its regulatory efforts on municipal
solid waste problems; the two elemental phosphorus facilities in the state both have permits for on-site
37 Recent revisions of risk factors for radiation exposure indicate that actual risks may even be a factor of two higher than those
stated here.
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7-24 Chapter 7: Elemental Phosphorus Production
industrial landfills, but are not currently subject to strict design or operating criteria. Tennessee recently
revised its regulations to address industrial solid wastes, including mineral processing wastes such as furnace
slag, more stringently. Montana exempts furnace slag from its solid waste regulations if it is disposed on-site,
as happens at the single Montana elemental phosphorus facility. Idaho's solid waste regulations do not address
any mineral processing wastes, though the state does ban the use of elemental phosphorus furnace slag in
construction materials for habitable structures. Only Tennessee appears to actively regulate surface water
discharges from furnace slag piles, while none of the states specifically apply fugitive dust control requirements
to these wastes.
Costs and Impacts of Subtitle C Regulation
Because of the low risk potential of on-site management of elemental phosphorus slag, the absence
of documented damages caused by on-site disposal of this material, and the fact that this waste does not exhibit
any characteristics of hazardous waste, EPA has not estimated the costs and associated impacts of regulating
elemental phosphorus slag under RCRA Subtitle C.
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Chapter 8
Ferrous Metals Production
For the purposes of this report, the ferrous metal industry consists of 28 facilities. These facilities
were, as of September 1989, active and reportedly generating one or more of the following special wastes from
mineral processing: iron blast furnace slag, iron blast furnace air pollution control dust/sludge, steel open
hearth furnace (OHF) or basic oxygen furnace (EOF) slag, and/or steel OHF or BOF air pollution control
dust/sludge. Of the 28 reportedly active facilities producing ferrous metals, as indicated in Exhibit 8-1, 24
facilities reported generating both iron and steel wastes at an integrated facility, two reported generating only
iron production wastes and two reported generating only steel production wastes. Of the 26 active steel mills,
23 employ basic oxygen furnaces, two employ open hearth furnaces, and one operates both types of steel
furnaces.1 Several iron foundry operations were surveyed but reportedly did not generate any special wastes
from mineral processing, and hence, have not been included in this report. The data included in this chapter
are discussed in additional detail in the appendices to and the supporting public docket for this report.
8.1 Industry Overview
Iron blast furnaces produce molten iron that can be cast (molded) into products, but is primarily used
as the mineral feedstock for steel production. Steel furnaces produce a molten steel that can be cast, forged,
rolled, or alloyed in the production of a variety of materials. On a tonnage basis, about nine-tenths of the
metal consumed in the United States is iron or steel. Iron and steel are used in the manufacture of
transportation vehicles, machinery, pipes and tanks, cans and containers, and the construction of large
buildings, roadway superstructures, and bridges.2
The 28 ferrous metal facilities are located in ten states; 21 of these facilities are in five states (Ohio,
Pennsylvania, Indiana, Illinois, and Michigan) that are situated around the Great Lakes, with immediate access
to the lake transport of beneficiated iron ore (taconite pellets). The average age of the iron facilities is
approximately forty-six years. The oldest active furnace reportedly is at the US Steel facility in Lorain, Ohio,
and is a blast furnace built in 1899 and modernized in 1968. All iron facilities have undergone modernization
during the past twenty years; at least 16 of the active facilities performed some modernization during the last
5 years. The average age of the BOFs is twenty-two years, with dates of initial operation ranging from 1958
to 1977; about half of these facilities have undergone modernization. The oldest active OHF operation
reportedly commenced operation in 1938; all three of these facilities have been modernized, two within the
last three years.
The annual aggregate production capacity of the iron facilities is 72.1 million metric tons; the
production was reported to be 49.1 million metric tons, resulting in an estimated average capacity utilization
rate of 68.1 percent3 The total annual aggregate production capacity was 72.2 million metric tons for the
basic oxygen furnaces and about 5.3 million metric tons for the open hearth furnaces.4 Total production was
1 The ferrous metals sector has, in addition to these 28 primary processing facilities, many secondary processors (e.g., electric arc
furnaces, all of which primarily use scrap for feedstock). The Mining Waste Exclusion is limited to facih'ties that use less than SO percent
scrap as feedstock, thus only steel facilities that do not rely primarily upon scrap as iron feedstock are considered here.
* Bureau of Mines, 1985. Mineral Facts and Problems. 1985 Ed., p. 412.
3 Environmental Protection Agency, 1989. "National Survey of Solid Wastes from Mineral Processing Facilities," 1989.
4 The average production capacities and utilization rates do not include data from one confidential facility with basic oxygen furnace
operations and one confidential facility with open hearth furnace operation.
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8-2 Chapter 8: Ferrous Metals Production
Exhibit 8-1
Domestic Iron and Steel Producers
Owner
Acme
Allegheny
Armco
Armco
Bethleftem Steel
Bethlehem Steel
Bethlehem Steel
Geneva
Gulf States Steel
Inland Steel
LTV
LTV
LTV
McLouth Steel
National Steel
National Steel
Rouge Steel
Sharon Steel
Snenango
US Steel
US Steel
US Steel
US Steel
US Steel
Warren Steel
Weirton Steel
Wheeling-Prttsburgn Steel
Wheeling-Pittsburgh Steel
Location
Rcverctale, it
Brackenridge, PA
Ashland, KY
Middletown, OH
Bethfehem, PA
Burns Harbor, IN
Sparrows Point, MO
Orem, UT
Gadsden, AL
E. Chicago, IN
E. Cleveland, OH
Indiana Harbor, IN
W. Cleveland, OH
Trenton, Ml
Escore, Ml
Granite City, IL
Dearborn, Ml
Farrell, PA
Pittsburgh, PA
Braddock, PA
Gary. IN
Fairfield, AL
Fairlees HSs. PA
Lorain, OH
Warren, OH
Weirton, WV
Mfeigo Junction, OH
Steuberwille, OH
, Type of Operation
lron;w BOF Steel
BOF Steel
Iron; BOF Steef
Iron; BOF Steel
Iron; SOF Steet
Iron; BOF, Steel
Iron; BOF, OHF Steet
Iron; OHF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steet
Iron; BOF Steel
Iron; BOF Steef
Iron; BOF Steel
Iron; BOF Steei
Iron; BOF Steel
Iron
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron: OHF Steel
Iron; BOF Steel
Iron; B0F Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel""
(a) Acme operates two blast furnaces, labeled A and B, at their Chicago Plant, Chicago, IL as reported in Iron and Steel Maker,
Volume 15, No.1; January 1968. They reported, however, no Bevill waste from blast furnace operations in the 1989
•National Survey of Solid Wastes from Mineral Processing Facilities'.
(b) Bureau of Mines has indicated that Wheeling-Pittsburgh Steel/Steubenville has a BOF steel operation; the company,
however, reported no steel production or generation of special wastes from steelmaking. EPA has assumed no production
is presently occuring.
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Chapter 8: Ferrous Metals Production 8-3
50.2 million metric tons for the basic oxygen furnaces and 2.4 million metric tons for the open hearth
furnaces.5 The estimated 1988 average capacity utilization rate was, therefore, 69.5 percent for the basic
oxygen furnaces and 45.3 percent for the open hearth furnaces.6
Overall primary production of pig iron was steady through the latter part of the 1980s, while
production of raw steel experienced a steady increase. Between 1985 and 1989, primary production of pig iron
averaged 46,000,000 metric tons, with almost all production being delivered to steel-making furnaces located
at the same site. Imports for consumption and exports of pig iron were negligible during the 1985 to 1989
period. Production of raw steel steadily increased from 74,000,000 metric tons in 1989 to 91,000,000 metric
tons in 1988, with a slight decrease of 3,000,000 metric tons in 1989. Imports of steel declined 28 percent
(from 23,000,000 metric tons to 17,000,000 metric tons) reflecting the relatively weak dollar and the worldwide
strength of the steel market. Due to the same factors, steel exports increased 300 percent (1,000,000 metric
tons to 4,000,000 metric tons).7
The long-term trend of declining steel-making capacity since 1978 (145,000,000 metric tons) seems
to have reversed recently. The capacity, reported by the American Iron and Steel Institute, has increased from
102,000,000 metric tons in 1988 to 104,000,000 metric tons in 1989. Approximately one-half of this increase
can be attributed to the start-up of two minimills and reactivation of an inactive minimill. Raw steel
production has experienced production levels well above those of the mid 1980s, with steel companies
reporting profits for the last three years.8
Iron is produced either by blast furnaces or by one of several direct reduction processes; blast
furnaces, however, account for over 98 percent of total domestic iron production.9 The modern blast furnace
consists of a refractory-lined steel shaft in which a charge is continuously added to the top through a gas seal.
The charge consists primarily of iron ore, sinter, or pellets; coke; and limestone or dolomite. Iron and steel
scrap may be added in small amounts. Near the bottom of the furnace, preheated air is blown in. The coke
is combusted to produce carbon monoxide, the iron ore is reduced to iron by the carbon monoxide, and the
silica and alumina in the ore and coke ash is fluxed with limestone to form a slag that absorbs much of the
sulfur from the charge. Molten iron and slag are intermittently tapped from the hearth at the bottom. The
slag is drawn off and processed. The product, pig iron, is removed and typically cooled, then transported to
a steel mill operation, as depicted in Exhibit 8-2.
All contemporary steelmaking processes convert pig iron, scrap, or direct-reduced iron, or mixtures
of these, into steel by a refining process that lowers the carbon and silicon content and removes impurities
(mainly phosphorus and sulfur). Three major processes are used for making steel, based on different furnace
types: the open hearth furnace, accounting for 2-4 percent of total domestic steel production; the basic oxygen
furnace, with 56-59 percent of the total; and the electric arc furnace accounting for the remainder. The latter
predominantly uses scrap (i.e., non-mineral material) as feed and is not discussed further in this report. The
open-heanh process was prevalent in the U.S. between 1908 and 1969, but its use has diminished. The basic
oxygen process has supplanted it as the predominant primary steel-making process, currently making up
approximately 95 percent of domestic primary steel production.10
During the open-hearth process, a relatively shallow bath of metal is heated by a flame that passes
over the bath from the burners at one end of the furnace while the hot gases resulting from combustion are
pulled out the other end. The heat from the exhaust gas is retained in the exhaust system's brick liners, which
5 The average production capacities and utilization rates do not include data from one confidential facility with basic oxygen furnace
operations and one confidential facility with open hearth furnace operation.
6 Environmental Protection Agency, 1989. "National Survey of Solid Wastes from Mineral Processing Facilities," 1989.
7 Anthony T. Peters, U.S. Bureau of Mines, Minrml Commodity Summaries. 1990 Ed., p. 88.
8 Ibid., p. 88-89.
9 American Iron and Steel Institute, 1984. "Annual Statistical Report," 1984, p. 78.
10 Bureau of Mines, 1987. Minerals Yearbook. Volume I, printed 1989, p. 511.
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8-4 Chapter 8: Ferrous Metals Production
Exhibit 8-2
Ferrous Metals Production
PROCESS
Ore or
Toconite Pellets
& Scrap
SPECIAL WASTE
MANAGEMENT
Processing and Sale
Legend
To Sinter Plant
Basic Oxygen
or Open
Hearth Furnace
Oxygen
Flux
Steel
Cleaned
Gas
I I Production Operation ^ ' Special Waste
Waste Management Unit
are known as checker-brick regenerators. Periodically the direction of the flame is reversed, and air is drawn
through what had been the exhaust system; the hot checker-bricks preheat the air before it is used in the
combustion in the furnace. Impurities are oxidized during the process and fluxes form a slag; this slag, the
special waste, is drawn off and processed or discarded.
The basic oxygen process uses a jet of pure oxygen that is injected into the molten metal by a lance
of regulated height in a basic refractory-lined convener. Excess carbon, silicon, and other reactive elements
are oxidized during the controlled blows, and fluxes are added to form a slag. This slag, one of the special
wastes, is drawn off and processed or discarded.
In all three operations, gases from the furnace must be cleaned in order to meet air pollution control
requirements. Facilities may use dry collection or wet scrubbers or, as is most often practiced, both types of
controls. Large volumes of dust and scrubber sludge are collected and processed or disposed; these air
pollution control residuals are also special wastes.
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Chapter 8: Ferrous Metals Production 8-5
Based on a review of available data, the Agency believes that the characteristics of the furnace slag
from the BOF and OHF processes are similar. Thus, in the remainder of this chapter, no distinction is made
between BOF slag and OHF slag; instead, the term "steel furnace slag" is used. For the same reasons APC
dusts/sludges from BOFs and OHFs are discussed under the general term "steel furnace APC dust/sludge."
8.2 Waste Characteristics, Generation, and Current Management Practices
Ferrous metal production operations generate four special mineral processing wastes: iron blast
furnace slag, iron blast furnace air pollution control dust/sludge, steel furnace slag, and steel furnace air
pollution control dust/sludge.
Several comments received by EPA on the rulemaking proposals that established the scope of this
report indicated that iron and steel slags should not be considered solid wastes. Based on the information on
slag storage, disposal, and utilization presented in this chapter and the definition of solid waste (40 CFR
261.2), some iron and steel slags are solid wastes. EPA recognizes, however, that there may be justification
for reconsideration of this position, and will, accordingly, consider comments on this issue. If EPA were to
decide that a change is warranted, this change could only be effected through a formal rulemaking process.
Iron Blast Furnace Slag
In 1988, iron blast furnace slag was generated at 26 of the 28 ferrous metal production facilities in
the U.S. ~ all twenty-four integrated iron/steel facilities and two additional iron blast furnace operations.
Blast furnace slag contains oxides of silicon, aluminum, calcium, and magnesium, along with other
trace elements. There are three types of blast furnace slag: air-cooled, granulated, and expanded. Air cooled
slag comprises approximately ninety percent of all blast furnace slag produced. The physical characteristics
of the slags are in large part determined by the methods used to cool the molten slag. All facilities
characterized their slags as solid, though slag is molten at the point of generation.
Non-confidential waste generation rate data were reported for all 26 facilities generating iron blast
furnace slag. The aggregate annual industry-wide generation of all iron blast furnace slag by the 26 facilities
was 18.8 million metric tons in 1988, yielding a facility average of over 724,000 metric tons per year. Reported
facility generation rates ranged from 95,000 to 8.0 million metric tons. The average waste-to-product ratio
(i.e., metric ton of iron blast furnace slag to metric ton of pig iron) was 0.384 in 1988.
The primary management practice for iron blast furnace slag is processing (e.g., granulating,
expanding, crushing, sizing) and sale for use as aggregate. One facility, as pan of a Corp of Engineers
approved fill project, deposits its slag in an adjacent water body in order to buildup land area that is intended
for use in managing other waste materials.11
Using available data on the composition of blast furnace slag, EPA evaluated whether the slag exhibits
any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and extraction procedure
(EP) toxicity. Based on analyses of 17 samples from eight facilities, the Agency does not believe the slag is
corrosive, reactive, ignitable, or EP toxic. Consequently, even in the absence of the regulatory exemption
provided by the Mining Waste Exclusion, EPA does not believe that this material would be subject to
regulation as a hazardous waste.
Iron Blast Furnace Air Pollution Control (APC) Dust/Sludge
In 1988, iron blast furnace APC dust/sludge was generated at 26 of the 28 ferrous metal facilities in
the U.S., including all 24 integrated iron/steel facilities and the two additional iron blast furnace operations.
11 Bureau of Mines, 1990. Personal Communications with BOM Commodity Specialist, 27 June, 1990.
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8-6 Chapter 8: Ferrous Metals Production
Air pollution control (APC) devices treat the top gases emitted from iron blast furnaces. The air
pollution control devices generate either dusts or sludges. APC dust/sludge is composed primarily of iron,
calcium, silicon, magnesium, manganese, and aluminum.
Non-confidential waste generation rate data were reported for all 26 facilities generating iron blast
furnace APC dust/sludge. The aggregate annual industry-wide generation of all iron APC dust/sludge by these
facilities was approximately 1.2 million metric tons in 1988, yielding a facility average of nearly 52,000 metric
tons per year. Reported facility generation rates ranged from 6,000 to 136,000 metric tons. The average
waste-to-product ratio (i.e., metric ton of iron blast furnace APC dust/sludge to metric ton of pig iron) was
0.026 in 1988.
As shown in Exhibit 8-3, the two primary waste management practices at the iron facilities regarding
APC dust/sludge are disposal in on-site units and the return of the material to the production process via the
sinter plant operation or blast furnace.
Using available data on the composition of blast furnace APC dust/sludge, EPA evaluated whether
this material exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and
EP toxicity. Based on available information and best professional judgment, the Agency does not believe that
the dust/sludge is corrosive, reactive, or ignitable, but some sludge exhibits the characteristic of EP toxicity at
some facilities. EP toxicity test concentrations of all eight inorganic constituents with regulatory levels are
available for the sludge from 16 facilities. Of these constituents, only selenium and lead concentrations
exceeded the EP toxicity levels. Of 64 samples analyzed, concentrations of selenium exceeded the EP toxicity
regulatory level in only 1 sample of the blast furnace APC sludge leachate (from the Ffcirless Hills facility),
and in that case, only by a factor of 1.07 (Le., seven percent over the standard). Lead concentrations exceeded
the EP toxicity level in 4 of 70 samples analyzed, and by as much as a factor of 5.8. These 4 samples
represented blast furnace APC sludge from the Sparrows Point, E. Cleveland, and Fairless Hills facilities.
Lead and selenium concentrations as determined by SPLP analyses did not exceed the EP toxicity regulatory
levels. In general, it is not likely that this waste would be regulated as a hazardous waste if it were to be
removed from the Mining Waste Exclusion, because it would pass the EP toxicity test (which is best applied
using multiple samples and a confidence limit) at most or all facilities.
Steel Furnace Slag
In 1988, steel furnace slag was generated at 26 of the 28 ferrous metal production facilities in the U.S.
including all twenty-four integrated iron/steel facilities and two additional steel-producing facilities. Steel slag
is composed of calcium silicates and ferrites combined with fused oxides of iron, aluminum, manganese,
calcium, and magnesium. At the point of generation, the slag is in a molten form. The molten slag is air-
cooled and is broken into varying sizes once processing (e.g., crushing) begins.
Non-confidential waste generation rate data were reported for 24 of the 26 facilities generating steel
furnace slag. The aggregate annual industry-wide generation of all steel furnace slag by these 24 facilities was
approximately 13.2 million metric tons in 1988, yielding a facility average of over 553,000 metric tons per year.
Reported facility generation rates ranged from 18,000 to 33 million metric tons. The average waste-to-product
ratio (metric ton of steel slag to metric ton of carbon steel) was 0.253 in 1988, ranging from 0.04 to 1.2.
The primary management practice for steel slag is processing (e.g., crushing, sizing) and sale for use
as aggregate, though several facilities dispose or stockpile their steel slag.
Using available data on the composition of steel slag, EPA evaluated whether the slag exhibits any
of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and EP toxicity. Based on
analyses of 13 samples from 9 facilities and best professional judgment, the Agency does not believe the slag
is corrosive, reactive, ignitable, or EP toxic. Therefore, this material would be unlikely to be subjected to
regulation as a hazardous waste at any facility that generates it, even if it were to be removed from the Mining
Waste Exclusion.
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Chapter 8: Ferrous Metals Production 8-7
Exhibit 8-3
Site-Specific Management of Iron ARC Dust/Sludge in 1988
Practice
Disposal on-stte
Return to the Sinter Plant
Return to the Blast Furnace
Sold
Off-site management
Management practice not reported
Reported not generating waste type
TOTAL
Number of FacilWm
APC Dust
6
10
0
1
7
1
1
26
APC Sludge
8
6
1
1
9
0
1
26
Steel Furnace Air Pollution Control (APC) Dust/Sludge
Steel furnace APC dust/sludge is generated at 26 of the 28 ferrous metal production facilities in the
U.S., including all 24 integrated iron/steel facilities and the two additional steel producing facilities. Steel APC
dust/sludge consists mostly of iron, with smaller amounts of silicon, calcium, and other metals.
Non-confidential waste generation rate data were reported in the SWMPF Survey for only 11 of the
26 facilities generating steel APC dust/sludge. In addition, non-confidential waste generation data were
reponed by the American Iron and Steel Institute (AISI), a trade association representing the ferrous metals
industry; the AISI data were used to supplement the incomplete survey data. Aggregate annual industry-wide
generation of all steel APC dust/sludge by the 24 non-confidential facilities was approximately 1.4 million
metric tons in 1988, yielding a facility average of nearly 61,000 metric tons per year. Reported facility
generation rates ranged from 1,600 to 419,000 metric tons. The average waste-to-product ratio (metric ton
of steel APC dust/sludge to metric ton of carbon steel) was 0.028 in 1988.
Waste management practices were reponed for only ten of the 26 facilities. Eight of the ten
reportedly dispose the APC dust/sludge on-site; the remaining two return the material to the production
process via the sinter plant operation.
Using available data on the composition of steel furnace APC dust/sludge, EPA evaluated whether
the sludge exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and
EP toxicity. Based on available information and best professional judgment, the Agency does not believe the
sludge is corrosive, reactive, or ignitable, but some sludge samples exhibit the characteristic of EP toxicity.
EP leach test concentrations of all eight inorganic constituents with EP toxicity regulatory levels are available
for the sludge from rive facilities of interest. Of these constituents, only selenium concentrations exceeded
the EP regulatory levels. Of seven samples analyzed, the concentration of selenium exceeded its regulatory
level in only one sample (from the Lorain facility in Ohio), and in this one case, only by a factor of 1.46.
Selenium concentrations as determined by SPLP analyses did not exceed the EP toxicity levels. Because
selenium rarely exceeds EP toxicity levels when analyzed by the EP leach test, EPA believes that if this
material is removed from the Mining Waste Exclusion, it will generally not be subject to regulation as a
hazardous waste.
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8-8 Chapter 8: Ferrous Metals Production
8.3 Potential and Documented Danger to Human Health and the Environment
In this section, EPA discusses two of the study factors required by Section 8002(p) of RCRA for four
wastes generated in the ferrous metal production sector: (1) potential risk to human health and the
environment associated with the management of iron blast furnace and steel furnace slag and iron blast furnace
and steel furnace air pollution control dust/sludge; and (2) documented cases in which danger to human health
and/or the environment has been proven. Overall conclusions about the hazards associated with each of these
four wastes are based on the Agency's evaluation of these two factors.
Because the characteristics and management of the two slags is similar, EPA discusses them together
in the following section, followed by a discussion of the two air pollution control dust/sludges.
8.3.1 Risks Associated With Iron Blast Furnace and Steel Furnace Slag
Any potential danger to human health and the environment from iron blast furnace and steel furnace
slag is a function primarily of the composition of the slags, the management practices that are used, and the
environmental settings of the facilities where the slags are generated and managed.
Iron Blast Furnace Slag Constituents of Concern
EPA identified chemical constituents in iron blast furnace slag that may pose a risk by collecting data
on the composition of slag and evaluating the intrinsic hazard of chemical constituents present in the slag.
Data on Iron Blast Furnace Slag Composition
EPA's characterization of iron blast furnace slag and its leachate is based on data from a 1989
sampling and analysis effort by EPAs Office of Solid Ttaste (OSW) and industry responses to a RCRA §3007
request in 1989. These data provide information on the concentrations of 21 metals, cyanide, and a number
of other inorganic constituents (i.e., chloride, fluoride, phosphorus, and sulfate) in total and leach test analyses,
and represent samples from 13 of the 26 facilities that generate blast furnace slag.
Concentrations in total (solid) samples of blast furnace slag are consistent for most constituents across
all data sources and facilities. Lead, zinc, and arsenic concentrations, however, vary over three orders of
magnitude across the facilities.
Concentrations of constituents from leach test analyses of blast furnace slag generally are consistent
across the data sources, types of leach tests (Le., EP, SPLP, and TCLP), and facilities. Iron concentrations
determined by EP analyses, however, are greater than two orders of magnitude higher than concentrations
detected by SPLP analysis.
Process for Identifying Constituents of Concern
As discussed in detail in Chapter 2, the Agency evaluated the data summarized above to determine
if blast furnace slag or slag leachate contain any chemical constituents that could pose an intrinsic hazard, and
to narrow the focus of the risk assessment The Agency performed this evaluation by first comparing the
constituent concentrations to conservative screening criteria and then by evaluating the environmental
persistence and mobility of constituents present in concentrations above the criteria. These screening criteria
were developed using assumed scenarios that are likely to overestimate the extent to which the slag
constituents are released to the environment and migrate to possible exposure points. As a result, this process
identifies and eliminates from further consideration those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic ecosystems, and water resources (see Exhibit 2-3). Given the conservative (i.e., overly
protective) nature of these screening criteria, contaminant concentrations in excess of the criteria should not,
-------
Chapter 8: Ferrous Metals Production 8-9
in isolation, be interpreted as proof of hazard. Instead, exceedances of the criteria indicate the need to
evaluate the potential hazards of the waste in greater detail.
Identified Constituents of Concern
Of the 26 constituents analyzed in blast furnace slag solids, only chromium is present at
concentrations exceeding a screening criterion. Chromium was detected at concentrations greater than a
screening criterion: it exceeds the inhalation screening criterion in four of twelve slag samples (representing
three of seven facilities). The maximum detected concentration of chromium exceeds the air pathway screening
criterion by only a factor of six. Chromium concentrations greater than the criterion indicate that the slag
could pose a cancer risk greater than IxlO"5 if slag dust were blown into the air and inhaled in a concentration
that equals the National Ambient Air Quality Standard for paniculate matter. As discussed in the following
section on release, transport, and exposure potential, EPA does not expect such large exposures to windblown
dust because of the large particle size of the slag and the large distance to potential receptors.
Exhibit 8-4 presents the results of the comparisons for blast furnace slag leach test analyses to the
risk screening criteria. This exhibit lists all constituents for which sample concentrations exceed a screening
criterion. As shown, comparison of leach test concentrations of 20 constituents to surface and ground-water
pathway screening criteria identified eight contaminants that are present at concentrations above the criteria.
All of these contaminants are metals or other inorganics that do not degrade in the environment. Manganese
and iron exceed a screening criterion in samples from at least 50 percent of all facilities from which samples
were analyzed. These two constituents, as well as lead, arsenic, and silver exceed at least one screening
criterion by factors of 10 or greater. The other constituents exceed screening criteria less frequently and by
a narrower margin. Previous EPA analyses also indicate that the pH of aqueous extracts of iron blast furnace
slag ranges from 5.0 to 11.9 standard units.12 Leachate data collected as part of the damage cases confirm
that leachate from the slag can be very basic (see Section 8.3.3). Despite these exceedances of the screening
criteria, none of the samples contained any constituents in excess of the EP toxicity regulatory levels.
These exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• If slag leachate were released to a potential drinking water supply, and diluted less than
tenfold during migration to a drinking water exposure point, long-term ingestion could
cause adverse health effects due to the presence of high concentrations of lead, arsenic,
and antimony. The concentration of arsenic in diluted slag leachate could pose a
lifetime cancer risk of greater than IxlO"5.
• Lead, aluminum, silver, and mercury in the slag leachate, as well as its alkalinity, could
present a threat to aquatic organisms if the leachate migrates (with less than 100-fold
dilution) to surface waters.
• Manganese, iron, and lead in the slag leachate, as well its alkalinity, could restrict the
potential future uses of affected ground- and surface water resources if released and
diluted by a factor of 10 or less.
EPA emphasizes that these exceedances of the screening criteria do not indicate that the slag is
actually causing the risks outlined above. Instead, the exceedances provide evidence that the slag could pose
these threats under hypothetical, very conservative release and exposure conditions. The actual slag
management conditions that influence risks are examined later in this section.
12 EPA. 1979. Environmental and Resource Conservation Considerations of Steel Industry Solid Waste. Office of Research and
Development. EPA-600/2-79-074.
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8-10 Chapter 8: Ferrous Metals Production
Exhibit 8-4
Potential Constituents of Concern in Iron Blast Furnace Slag Leachate^
Potential
Constituents
of Concern
Manganese
Iron
Lead
Arsenic
Aluminum
Silver
Mercury
Antimony(c)
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
6/6
6/6
10/18
4/18
6/6
5/18
5/18
1/6
Screening Criteria0"
Resource Damage
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Human Health"
Aquatic Ecological
Aquatic Ecological
Aquatic Ecological
Human Health
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
6/6
4/6
5/18
7/18
2/18
4/18
3/6
3/18
1/18
1/6
No. of Facilities
Exceeding Criteria'/
No. of Facilities
Analyzed for
Constituent
5/5
3/5
2/9
3/9
2/9
1 /9
2/5
2/9
1/9
1 /5
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that
exceeds a relevant screening criterion. The conservative screening criteria used in this analysis are listed in
Exhibit 2-3. Constituents that were not detected in a given sample were assumed not to be present in the sample.
Unless otherwise noted, the constituent concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. 'Human hearth* screening
criteria noted with an '*' are based on a 1x10"* lifetime cancer risk; others are based on noncancer effects.
(c) Data for this constituent are from SPLP leach test results.
Steel Furnace Slag Constituents of Concern
Using the same process outlined above, EPA identified chemical constituents in carbon steel furnace
slag that may pose a risk by collecting data on the composition of the slag, and evaluating the intrinsic hazard
of the slag's chemical constituents.
Data on Steel Furnace Slag Composition
EPAs characterization of steel furnace slag and its leachate is based on data from a 1989 sampling
and analysis effort by EPAs Office of Solid Waste (OSW) and industry responses to a RCRA §3007 request
in 1989. These data provide information on the concentrations of 20 metals, cyanide, ammonia, and a number
of other inorganic constituents (i.e., phosphorus, phosphate, sulfate, and fluoride) in total and leach test
analyses, and represent samples from 14 of the 26 facilities that generate steel furnace slag.
Concentrations in total (solid) samples of the steel furnace slag are consistent for most constituents
across all data sources and facilities. Mercury and silver concentrations, however, vary over three orders of
magnitude across the facilities.
Concentrations of constituents from leach test analyses of the steel furnace slag generally are
consistent across the data sources and facilities. In the EP analyses, however, arsenic, iron, and manganese
concentrations varied over approximately three orders of magnitude across the facilities. For most
constituents, maximum EP leach test concentrations are somewhat higher than maximum SPLP leach test
concentrations.
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Chapter 8: Ferrous Metals Production 8-11
Identified Constituents of Concern
Exhibits 8-5 and 8-6 present the results of the comparisons for steel furnace slag solid analyses and
leach test analyses, respectively, to the risk screening criteria. These exhibits list all constituents for which
sample concentrations exceed a screening criterion.
Of the 24 constituents analyzed in steel furnace slag solids, only chromium, thallium, manganese,
arsenic, and nickel are present at concentrations exceeding the screening criteria (see Exhibit 8-5). All of these
constituents are metals or other inorganics that do not degrade in the environment. Chromium, thallium, and
manganese concentrations exceed the criteria most frequently -- in 57 to 100 percent of the samples and in
samples from at least one-half of the facilities analyzed. Maximum concentrations of chromium, thallium, and
arsenic exceed screening criteria by factors of greater than 10. All other constituents exceed the criteria by
a narrower margin.
• Chromium, thallium, and arsenic concentrations exceed the ingestion criteria. This
indicates that, if the slag (or soil contaminated with the slag) is incidentally ingested on
a routine basis (e.g., if children are allowed to play on abandoned slag piles), then these
constituents may cause adverse health effects. The concentration of arsenic in the slag
could pose a lifetime cancer risk exceeding IxlO"5 if incidentally ingested.
• Chromium, manganese, arsenic, and nickel concentrations exceed the health-based
screening criteria for inhalation. This indicates that these constituents could cause
adverse effects on the central nervous system (manganese) or pose a cancer risk greater
than IxlO"5 (chromium, arsenic, and nickel) if slag dust were blown into the air and
inhaled in a concentration that equals the National Ambient Air Quality Standard for
paniculate matter. Based on the large particle size of the slag and the large distance
to potential receptors, however, EPA does not expect such large exposures to windblown
dust (as discussed in the next section).
Based on a comparison of leach test concentrations of 23 constituents to surface and ground-water
pathway screening criteria (see Exhibit 8-6), eight contaminants in the slag leachate were detected in
concentrations above the criteria. All of these contaminants are metals or other inorganics that do not
degrade in the environment. Manganese, fluoride, arsenic, and lead concentrations in samples from at least
30 percent of the facilities analyzed exceed screening criteria. Maximum concentrations of manganese, arsenic,
and iron exceed screening criteria by factors of more than 10. Leachate data collected during the damage case
investigation (see Section 8.3.3) also indicate that the slag leachate can be very basic. However, no
constituents were measured in the leachate in concentrations that exceed the EP toxicity regulatory levels.
These exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
Concentrations of fluoride, arsenic, lead, and barium in steel furnace slag leachate
exceed health risk (drinking water) screening criteria. This indicates that, if slag
leachate were released and diluted less than tenfold during migration to a drinking
water exposure point, long-term ingestion could cause adverse health effects due to the
presence of these constituents. The concentration of arsenic in diluted slag leachate
could pose a cancer risk of greater than IxlO"5.
• Lead and silver in the slag leachate, as well as its alkalinity, could present a threat to
aquatic organisms if it migrates (with less than 100-fold dilution) to surface waters.
• Manganese, fluoride, arsenic, lead, iron, molybdenum, and barium in the slag leachate,
as well as its alkalinity, could restrict the potential future uses of affected ground- and
surface water resources if released and diluted by a factor of 10 or less.
Again, EPA emphasizes that the criteria exceedances outlined above should not be interpreted as
proof of hazard, but rather indicate the need to examine the slag's release and exposure conditions in greater
detail. The Agency therefore proceeded to the next step of the risk assessment to analyze the actual conditions
that exist at the facilities that generate and managed the waste.
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8-12 Chapter 8: Ferrous Metals Production
Exhibit 8-5
Potential Constituents of Concern in Steel Furnace Slag Solids^
Potential
Constituents
of Concern
Chromium
Thallium
Manganese
Arsenic
Nickel
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
12/12
4/7
10/10
7/11
3/9
Human Hearth
Screening Criteria0*'
Inhalation*
Ingestion
Ingestion
Inhalation
Ingestion*
Inhalation*
Inhalation
No. of Analyses
Exceeding Criteria/
No. of Analyse* for
Constituent
12/12
1 /12
4/7
6/10
3/11
2/11
1/9
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
7/7
1 17
3/6
5/9
3/8
2/8
1 17
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an'"' are based on a 1x10'5 lifetime cancer
risk; others are based on noncancer effects.
Exhibit 8-6
Potential Constituents of Concern in Steel Furnace Slag Leachate^
Potential
Constituents
of Concern
Manganese
Fluoride
Arsenic**
Lead
Silver
Iron
Molybdenum
Barium
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
3/6
1 /1
3/8
4/14
2/1*
3/6
2/8
7/14
Screening Criteria***
Resource Damage
Human Health
Resource Damage
Human Health*
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
Resource Damage
Resource Damage
Human Health
Resource Damage
No. of Analyse*
Exceeding Criteria/
No. of Analyses for
Constituent
3/6
1 /1
1 /1
3/8
1/8
3/14
4/14
3/14.
2/14
1/6
1/8
1/14
1 /14
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
3/5
1 /1
1 /1
2/5
1/5
3/10
3/10
3/10
2/10
1 /5
1/7
1 /10
1 /10
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. Unless otherwise
noted, the constituent concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. 'Human health* screening criteria
noted with an '*' are based on a 1x10"s lifetime cancer risk; others are based on noncancer effects.
(c) Data for this constituent are from SPLP leach test results.
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Chapter 8: Ferrous Metals Production 8-13
Release, Transport, and Exposure Potential
This analysis considers the baseline hazards of blast furnace and steel furnace slag as they were
generated and managed at six and seven plants, respectively, in 1988. For this analysis, the Agency did not
have sufficient data to assess (1) the hazards of off-site use or disposal of the slags, (2) risks associated with
variations in waste management practices or potentially exposed populations in the future, or (3) the hazards
of alternative management practices. Alternative practices for the management of blast furnace and steel
furnace slag, however, are discussed in Section 8.5.
The Agency evaluated the potential hazards posed by the management of blast furnace and steel
furnace slag for only the facilities that provided information on on-site slag management units in their
responses to the National Survey of Solid W-istes from Mineral Processing Facilities. Of the 20 facilities that
generate blast furnace slag but are not evaluated below, 17 facilities responded that blast furnace slag is sold
for processing and subsequent use, and 3 facilities identified on-site management units containing blast furnace
slag (a stockpile, a temporary storage unit, and slag pits) but provided no details on the characteristics of these
units. Of the 19 facilities that generate steel furnace slag but are not evaluated, one facility identified an on-
site management unit containing this slag (i.e., a stockpile) but provided no details on the characteristics of
this unit, one facility requested that all information in its survey be held confidential, and the other 17 facilities
responded that all of the steel furnace slag that they generated in 1988 was recycled or processed and sold.
Because the slag management units described by the facilities the Agency analyzed include both slag pits and
stockpiles, such as might be present at the facilities that sell slag for processing and off-site use, EPA expects
that the hazards at the facilities that are evaluated reflect the nature of the potential threats posed by blast
furnace and steel furnace slag at the other facilities that generate these materials.
Ground-Water Release, Transport, and Exposure Potential
EPA and industry test data discussed above show that several constituents are capable of leaching
from blast furnace and steel furnace slag in concentrations above the screening criteria. Considering only
those constituents that are relatively mobile in ground water (given the existing slag management practices and
expected pH levels of the leachate), blast furnace slag contaminants that pose the primary potential threat are
arsenic and mercury, and steel furnace slag constituents that present the greatest potential threat are fluoride,
arsenic, and molybdenum. In addition, the high pH of slag leachate conceivably could threaten ground-water
resources. Based on an evaluation of management practices, hydrogeologic settings, and current ground-water
use patterns, EPA concludes that the potential for ground water release and transport ranges from low to
relatively high at the eleven facilities for which management unit information is available. However, the
potential for significant exposure to any released contaminants appears low at most of these facilities.
Although their slag management units are not equipped with liners or other engineered controls to
restrict releases to ground water, the Geneva, USX/Lorain, LTV/East Cleveland, Rouge, and Inland plants
have relatively low ground-water contamination potential.
• Ground-water contamination potential is low at the Geneva, USX/Lorain, and LTV/East
Cleveland plants because net ground-water recharge at these locations is moderately low
(8 to 15 crn/yr) and aquifers are relatively deep (15 to 23 meters).
• The potential for ground-water contamination at Rouge is low because the uppermost
useable aquifer lies beneath a confining layer. This confining layer is known to be an
effective barrier because the underlying aquifer is artesian (i.e., it has a hydraulic head
higher than the surrounding land surface).
• At the Inland plant, blast furnace slag is deposited in an area along the shore of Lake
Michigan. Because slag is placed in the lake, slag constituents can readily be leached
by lake waters. Nonetheless, there is little potential for contamination of the underlying
ground water because of the large depth to the usable aquifer underlying the facility (21
meters).
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8-14 Chapter 8: Ferrous Metals Production
At the Geneva plant, downgradient use of ground water may occur at a distance of less than 100
meters from the facility. However, considering the low release potential at this site and the generally low
concentrations of contaminants in the leachate, the concentrations at this exposure point are expected to be
below levels of concern. At the other plants with low ground-water release potential, the potential for
exposure is also low because there are no downgradient private residences or public supply wells within 1.6
km (1 mile) downgradient of the plants.
Ground-water release potential is moderate at USX/Eairless Hills, Sharon, Allegheny, and "Warren.
Because slag management units at these plants do not have ground-water release controls, infiltrating
precipitation (net ground-water recharge at these plants ranges from 15 to 23 cnvyr) can leach slag
constituents directly into the subsurface and into ground water that occurs 4 to 6 meters below the land
surface. Releases to ground water at all four plants, if not sufficiently diluted, could render affected aquifers
unsuitable for potential uses. Any ground-water contamination at the Fairless Hills and Warren plants
conceivably could result in drinking water exposures at a residence located 150 meters downgradient of the
Fairless Hills facility and a public supply well (serving 160 people) located 460 meters downgradient of the
\Vkrren facility. Contaminant concentrations at these exposure points, however, are likely to be below levels
of concern.
Slag management at the Bethlehem/Bethlehem and Weirton plants poses a relatively high potential
for contaminants to migrate into ground water.
• The landfill used to dispose of steel furnace slag at Bethlehem/Bethlehem is located only
3 meters above ground water and recharge in this area is 23 cm/yr.
• At Weirton, blast furnace slag is cooled with water in pits that are lined with
recompacted local clay and steel furnace slag is stored in a slag pile that has no ground-
water release controls such as a liner or leachate collection system. The clay liner at the
blast furnace slag pit may limit the potential for slag cooling water to seep from these
pits to the subsurface, but if this liner should fail, releases could migrate through the
sandy subsurface materials to the usable aquifer located just over 3 meters (10 feet)
below the bottom of the pits.
Despite these unfavorable conditions, no ground-water contamination attributable to the slag management
units at these sites has been observed. If such contamination were to occur in the future, it could render
ground water unsuitable for potential uses but would not threaten current human populations because there
are no downgradient wells within 1.6 km (1 mile) of either facility.
Surface Water Release, Transport, and Exposure Potential
In theory, constituents of potential concern in blast furnace and steel furnace slag could enter surface
waters by migration of slag leachate through ground water that discharges to surface water, or direct overland
(stormwater) run-off of dissolved or suspended slag materials. The constituent concentrations and pH levels
detected in blast furnace and steel furnace slag leachate confirm that the potential exists for slag contaminants
to migrate into surface water in a leached form. The potential for overland release of slag particles to surface
waters is limited considerably by the generally large size of the slag fragments. A small fraction of the slag
material, however, may consist of fragments that are small enough to be credible. Only particles that are 0.1
mm or less in size tend to be appreciably credible,13 and only a very small fraction of the blast furnace and
steel furnace slag solids are expected to be in this size range.
Based on environmental settings of the facilities and the presence of stormwater run-on/run-off
controls at slag management units, the potential for contaminants from blast furnace and steel furnace slag
to migrate into surface water at the eleven facilities appears to range from relatively low to relatively high.
The potential for significant exposure to these contaminants, however, appears moderate at most.
13As indicated by the soil credibility factor of the USDA's Universal Soil Loss Equation.
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Chapter 8: Ferrous Metals Production 8-15
The slag stockpile at Geneva has a relatively low potential for causing surface water contamination.
Overland releases from this facility are limited by stormwater run-off controls and ground-water releases are
limited by the large depth to the aquifer and small net recharge.
Slag management units at Allegheny, Weirton, and Bethlehem/Bethlehem pose a moderate threat to
surface waters. The units at these facilities have a limited potential for causing surface water contamination
via overland flow of erodible slag particles or leached slag constituents because the piles and pits at these
facilities are equipped with run-off controls. However, as discussed above, the potential for ground-water
contamination from the slag management units at these plants is moderate to high, and potential ground-water
contaminants may discharge to the surface waters that are within 50 meters of the facilities. Furthermore, the
Weirton and Bethlehem/Bethlehem facilities are located in 100-year floodplains and, therefore, are susceptible
to severe erosion that might occur in the event of a flood. Even if contamination from the slag management
units at these facilities did reach the nearby Allegheny, Ohio, and Lehigh rivers, the contaminants would likely
be diluted below levels of concern in the rivers' large flow (the annual average flow of these rivers ranges from
1,400 mgd to 22,000 mgd).
Slag management units at the other seven facilities have a relatively high potential to contaminate
surface waters. The USX/Eairless, Inland, Rouge, Sharon, LTV/East Cleveland, Warren, and USX/Lorain
facilities are all located adjacent to or very near surface waters and have no controls to limit ground-water
infiltration or stormwater run-off. The potential risks posed by releases from these plants depends on the size
and current uses of the receiving water bodies.
• The Rouge, LTV/East Cleveland, and USX/Lorain plants pose moderate to low human
health risks because contaminants from these facilities could enter rivers with moderate
to relatively large flows (Le., 145 to 580 mgd) that are used as drinking water supplies.
The potential for adverse effects is highest at Rouge because the Rouge River has the
smallest flow and is used as a drinking water supply for 1.2 million people (intake is 10
km downstream). The Cuyahoga and Black rivers near LTV/East Cleveland and
USX/Lorain are larger than the Rouge River, but also used as a drinking water supply
within 24 km downstream.
• Releases from the Sharon and Warren plants could potentially enter the Shenango and
Mahoning rivers, respectively, where they would be diluted (the rivers' annual average
flows are 430 and 580 mgd, respectively). If the contamination was not sufficiently
diluted, it could endanger aquatic life and potential consumptive uses of the river water.
• Slag management units at USX/Fairless Hills and Inland are located adjacent to (or in)
large water bodies (i.e., the Delaware River and Lake Michigan) that can assimilate
large quantities of contaminants. Therefore, it is unlikely that releases from these
facilities would adversely affect aquatic life or potential uses of these water bodies.
Air Release, Transport, and Exposure Potential
Because all of the constituents that exceed the inhalation screening criteria (i.e., chromium,
manganese, arsenic, and nickel) are nonvolatile, blast furnace and steel furnace slag contaminants can only be
released to air in the form of dust particles. Dust can be either blown into the air by wind or suspended in
air by slag dumping and crushing operations. Factors that affect the potential for such airborne releases
include the particle size of the slag, the height and exposed surface area of the slag management units, the slag
moisture content, the use of dust suppression controls, and local wind speeds. The potential for exposure to
airborne dust depends on the proximity to nearby residences.
The generally large size of blast furnace and steel furnace slag fragments limits the potential for
release of airborne slag dust, because in general, only particles that are less than 100 micrometers (um) in
diameter are wind suspendable and transportable. Within this range, moreover, only particles that are less
than 30 um in diameter can be transported for considerable distances downwind, and only particles that are
less than 10 um in diameter are respirable. The vast majority of blast furnace and steel furnace slag is
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8-16 Chapter 8: Ferrous Metals Production
substantially larger than 100 urn and thus should not be suspendable, transportable, or respirable. It is likely
that only a very small fraction of the slag will be weathered and aged (or crushed) into smaller panicles that
can be suspended in air and cause airborne exposures and related impacts.
Other factors that affect the potential for airborne release and exposure vary on a site-specific basis
as follows:
• Dust suppression is practiced at the slag management units at Geneva, Allegheny, and
Warren. However, because winds are sufficiently strong, if this control is not effective
or is discontinued, small slag particles could be suspended and pose health risks at
residences located within 100 meters of the facilities. The 1,500; 5,000; and 20,000
residents within 1.6 km (1 mile) of the Geneva, Allegheny, and Warren facilities,
respectively, might then be exposed to airborne slag panicles.
• Weirton and Rouge manage slag in small units (i.e., .04 to .46 acres) that are not
equipped with dust controls. The small size of these units and the generally large size
of slag fragments limit the potential for slag to become airborne and be respired. In the
event that small slag panicles are released to the air, exposures and associated risks
would be higher at the Weirton facility than at Rouge because of the differences in
distance to the nearest residence (25 m and 275 m, respectively) and the size of the
nearby populations (15,000 and 12,000 people within 1.6 km (1 mile), respectively).
• At the USX/Fairless, Inland, Sharon, USX/Lorain, Bethlehem/Bethlehem, and LTV/East
Cleveland facilities, the slag management units range from approximately .4 to 140
hectares (1 to 348 acres) in area. These units are not covered with either vegetation or
a synthetic material, and the facilities do not use any dust suppression controls, such as
sprinkling water on the units. However, the number of days with rain, which may
suppress dust, is relatively large (95 to 160 days/yr). As a result, the surface of the slag
is expected to be moist much of the time. Short term gusts of strong winds could
produce wind erosion of fine particles. Based on these factors, the potential for dusting
is moderate at all seven facilities. Windblown dust could lead to potential exposures at
these facilities because the nearest residence in a predominant wind direction is less
than 700 meters away and the population within 1.6 km (1 mile) ranges from 2,000 to
35,000.
Proximity to Sensitive Environments
Twenty-three of the 26 iron production facilities, and 21 of 26 steel production facilities are located
in or near environments that are vulnerable or that have high resource value, such as wetlands, 100-year
floodplains, fault zones, national forests, or endangered species habitats. In particular:
• The Geneva facility is located near the critical habitat of a federally listed endangered
species - the June Sucker. Because the critical habitat of this fish is upstream (in the
Provo River) from the facility, it is unlikely that releases of waste constituents from the
Geneva plant could threaten this habitat.
• Warren, Weirton, USX/Lorain, Shenango (iron only), LTV/East Cleveland,
WP/Steubenville (iron only), W-P/Mingo Junction, National/Great Lakes, Bethlehem/
Bethlehem, Rouge, Bethlehem/Sparrows Point, USX/Fairless Hills, Gulf States,
National/Granite City, and USX/Braddock all have part of their facilities located within
100-year floodplains. Management of wastes in floodplains creates the potential for
large, episodic releases caused by flood events.
• USX/Lorain, Bethlehem/Sparrows Point, and USX/Fairless Hills have wetlands (defined
here to include swamps, marshes, bogs, and other similar areas) within their facility
boundaries. Bethlehem/Burns Harbor, Inland, LTV/East Cleveland, LTV/Indiana
Harbor, McLouth, USX/Gary, and Geneva are located within 1.6 km (1 mile) of
wetlands. Wetlands are commonly entitled to special protection because they provide
habitats for many forms of wildlife, purify natural water, provide flood and storm
-------
Chapter 8: Ferrous Metals Production 8-17
damage protection, and afford a number of other benefits. Contamination from these
sites could potentially cause adverse effects in adjacent or nearby wetlands.
• Bethlehem/Bethlehem and USX/Fairless Hills are located in an area of karst terrain
characterized by sink holes and underground cavities developed by the action of water
in soluble rock (such as limestone or dolomite). Solution cavities that may exist in the
bedrock at this site could permit any ground-water contamination originating from the
wastes to migrate in a largely unattenuated and undiluted fashion.
• USX/Fairfield and ARMCO/Ashland are located in fault zones. Any waste containment
systems in fault zones are subject to episodic damages caused by earthquakes.
• Bethlehem/Burns Harbor is located within 1.6 km (1 mile) of a National Park. The air
and water resources of the National Park potentially could be adversely affected by
nearby waste management, and recreational activities at the park could allow exposures
to waste constituents released from the nearby ferrous metal production facility.
8.3.2 Risks Associated With Iron Blast Furnace and
Steel Furnace Air Pollution Control Dust/Sludge
Any potential danger to human health and the environment from iron blast furnace and steel furnace
air pollution control (APC) dust/sludge is a function primarily of the composition of the wastes, the
management practices that are used, and the environmental settings of the facilities where the wastes are
generated and managed.
Blast Furnace APC Dust/Sludge Constituents of Concern
Using the same process outlined above for blast furnace slag, EPA identified chemical constituents
in the blast furnace APC dust/sludge that may pose a risk by collecting data on the composition of the waste,
and evaluating the intrinsic hazard of the waste's chemical constituents.
Data on Iron Blast Furnace APC Dust/Sludge Composition
EPAs characterization of blast furnace APC dust/sludge and its leachate is based on data from a 1989
sampling and analysis effort by EPAs Office of Solid Waste and industry responses to a RCRA §3007 request
in 1989. These data provide information on the concentrations of 20 metals, cyanide, ammonia, and a number
of other inorganic constituents (e.g., phosphorus, phosphate, fluoride, and sulfate) in total and leach test
analyses, and represent samples from 17 of the 26 facilities that generate blast furnace APC dust/sludge.
Concentrations in total (solid) samples of the blast furnace APC dust/sludge are consistent for most
constituents across all data sources and facilities. Arsenic, mercury, nickel, and selenium concentrations,
however, vary over three orders of magnitude across the facilities.
Concentrations of many constituents from leach test analyses of blast furnace APC dust/sludge
generally are consistent across the data sources and facilities. In the EP analyses, however, barium, cadmium,
chromium, copper, cyanide, lead, and selenium concentrations vary over approximately three orders of
magnitude across the facilities. Concentrations of many constituents are higher in EP leach test results than
in either SPLP or TCLP test results. EP test concentrations of cadmium, copper, and iron are more than two
orders of magnitude higher than the highest concentrations of these constituents in SPLP or TCLP results.
Identified Constituents of Concern
Exhibits 8-7 and 8-8 present the results of the comparisons for blast furnace APC dust/sludge solid
analyses and leach test analyses, respectively, to the risk screening criteria. These exhibits list all constituents
for which sample concentrations exceed a screening criterion.
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8-18 Chapter 8: Ferrous Metals Production
Exhibit 8-7
Potential Constituents of Concern in Blast Furnace APC Dust/Sludge Solids^
Potential
Constituents
of Concern
Chromium
Lead
Arsenic
Antimony
Cadmium
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
43/46
46/47
15/36
6/9
27/44
Human Health
Screening Criteria04
inhalation*
Ingestion
digestion*
Inhalation
Ingestion
inhalation
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
43/46
23/47
12/36
3/36
1 19
2/44
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
13/13
11 /14
5/12
2/12
1 17
1/12
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10'5 lifetime cancer
risk; others are based on noncancer effects.
Of the 25 constituents analyzed in blast furnace APC dust/sludge solids, only chromium, lead, arsenic,
antimony, and cadmium are present at concentrations exceeding the screening criteria (see Exhibit 8-7).
Among these constituents, chromium and lead exceed the criteria most frequently ~ in 51 to 93 percent of the
samples analyzed and in samples from at least 11 of 14 facilities. Only chromium and antimony are present
in concentrations greater than 10 times a screening criterion. All of these constituents are metals or other
inorganics that do not degrade in the environment
• Lead, arsenic, and antimony concentrations exceed the ingestion criteria. This indicates
that, if the dust/sludge (or soil contaminated with the waste) is incidentally ingested on
a routine basis (e.g., if children are allowed to play on abandoned waste piles), then
these constituents may cause adverse health effects. The concentration of arsenic in the
dust/sludge could pose a lifetime cancer risk greater than IxlO'5 if incidentally ingested
on a routine basis.
• Chromium, arsenic, and cadmium concentrations exceed the health-based screening
criteria for inhalation. This indicates that these constituents could pose a cancer risk
greater than IxlO'5 if the dust were blown into the air and inhaled in a concentration
that equals the National Ambient Air Quality Standard for paniculate matter.
Based on a comparison of leach test concentrations of 23 constituents to surface and ground-water
pathway screening criteria (see Exhibit 8-8), 17 contaminants were detected at levels above the criteria. All
of these constituents are persistent in the environment (i.e., they do not degrade). Manganese, lead, arsenic,
aluminum, iron, zinc, and fluoride exceed at least one screening criterion in samples from at least 50 percent
of all facilities at which they were analyzed. Although their concentrations exceed screening criteria less
frequently, copper, mercury, and thallium concentrations are more than 40 times higher than the screening
criteria. The only constituents that were detected in concentrations above the EP toxicity regulatory levels,
however, were lead (in 4 of 70 samples) and selenium (in 1 of 64 samples). In addition, previous EPA analyses
indicate that the pH of the aqueous fraction of the dust/sludge ranges from 9.5 to 11.7 standard units.14
14 EPA. 1979. Environmental and Resource Conservation Considerations of Steel Industry Solid Waste. Office of Research and
Development. EPA-600/2-79-074.
-------
Chapter 8: Ferrous Metals Production 8-19
Exhibit 8-8
Potential Constituents of Concern in Blast Furnace ARC Dust/Sludge Leachate(a)
Potential
Constituents
of Concern
Manganese
Lead
Arsenic
Aluminum
Iron
Zinc
Fluoride
Selenium
Thallium
Mercury
Silver
Copper
Antimony
Cadmium
Chromium
Barium
Nickel
No. of Times
Constituent
Detected/No, of
Analyse*
for Constituent
6/6
47/72
31/71
6/6
11/12
27/31
5/5
19/66
2/8
16/70
23/59
22/34
5/13
39/72
39/72
50/71
1S/25
Screening Criteria0"
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Human Health*
Aquatic Ecological
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Resource Damage
Aquatic Ecological
Human Health
Aquatic Ecological
Aquatic Ecological
Aquatic Ecological
Human Health
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecoteglcal
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
1/6
25/72
45/72
18/72
29/71
5/6
11/12
4/t2
3/31
3/31
17/31
3/5
3/5
4/66
1 /66
2/e
3/70
14/59
4/34
3/13
2/72
4/72
3/72
3/72
1/72
2/71
1/25
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
5/5
13/16
14/16
9/16
8/16
5/5
7/7
2/7
2/11
2/11
10/11
1/2
1/2
4/15
1 /15
1/6
3/15
7/15
2/9
2/7
2/16
4/16
3/16
2/16
1 /ie
1 /15
1/10
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. The constituent
concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. 'Human health' screening criteria
noted with an '"" are based on a 1x10"* lifetime cancer risk; others are based on noncancer effects.
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8-20 Chapter 8: Ferrous Metals Production
While this pH is well above the drinking water maximum contaminant level and the ambient water quality
criterion for the protection of aquatic life, it does not exceed the limits used to define a corrosive hazardous
waste. These exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• Concentrations of lead, arsenic, zinc, fluoride, thallium, antimony, and cadmium in blast
furnace APC dust/sludge leachate exceed health risk (drinking water) screening criteria.
This indicates that, if leachate from this waste were released and diluted by only a factor
of 10 during migration to a drinking water exposure point, long-term ingestion could
cause adverse health effects due to the presence of these constituents. The con-
centration of arsenic in diluted dust/sludge leachate could pose a cancer risk of greater
than IxlO"5-
• Lead, aluminum, iron, zinc, selenium, mercury, silver, copper, cadmium, chromium, and
nickel in the dust/sludge leachate, as well as its alkalinity, could present a threat to
aquatic organisms if it migrates (with less than 100-fold dilution) to surface waters.
• Manganese, lead, iron, zinc, fluoride, selenium, cadmium, chromium, and barium in the
APC dust/sludge leachate, as well as its alkalinity, could restrict the potential future uses
of affected ground- and surface water resources if released and diluted by a factor of 10
or less.
These exceedances of the screening criteria, by themselves, do not demonstrate that the dust/sludge
poses a significant risk, but rather indicate that the waste could pose a risk under a very conservative,
hypothetical set of release, transport, and exposure conditions. lb determine the potential for the dust/sludge
to cause significant impacts, EPA proceeded to the next step of the risk assessment to analyze the actual
conditions that exist at the facilities that generate and manage the waste (see the following section on release,
transport, and exposure potential).
Steel Furnace APC Dust/Sludge Constituents of Concern
Using the same process outlined above for the other three special wastes from ferrous metals
production, EPA identified chemical constituents in the steel furnace APC dust/sludge that may pose a risk
by collecting data on the composition of the waste, and evaluating the intrinsic hazard of the waste's chemical
constituents.
Date on Steel Furnace APC Dust/Sludge Composition
EPA's characterization of steel furnace APC dust/sludge and its leachate is based on data from a 1989
sampling and analysis effort by EPAs Office of Solid Waste and industry responses to a RCRA §3007 request.
These data provide information on the concentrations of 20 metals, chloride, and sulfate in total and leach
test analyses, and represent samples from 6 of the 26 facilities that generate steel furnace APC dust/sludge.
Concentrations in total (solid) samples of the steel furnace APC dust/sludge are consistent for most
constituents across all data sources and facilities. Sulfate and zinc concentrations, however, vary over more
than two orders of magnitude across the facilities.
Concentrations of constituents from leach test analyses of the steel furnace APC dust/sludge generally
are consistent across the data sources and facilities. In the EP analyses, however, iron and zinc concentrations
vary over approximately three orders of magnitude across the facilities. For most constituents, EP leach test
results are somewhat higher than SPLP test results. Maximum EP leach test concentrations of iron,
manganese, and zinc are more than two orders of magnitude higher than concentrations of the constituents
reported for SPLP analyses.
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Chapter 8: Ferrous Metals Production 8-21
Identified Constituents of Concern
Exhibits 8-9 and 8-10 present the results of the comparisons for steel furnace APC dust/sludge
analyses and leach test analyses, respectively, to the risk screening criteria. These exhibits list all constituents
for which sample concentrations exceed a screening criterion.
From the 22 constituents analyzed in steel furnace APC dust/sludge solids, only chromium, lead,
thallium, antimony, and arsenic are present at concentrations exceeding the screening criteria (see Exhibit 8-9).
For all of these constituents except arsenic, concentrations detected in most samples analyzed (57 to 100
percent) exceed screening criteria, and concentrations in samples from at least two facilities exceed screening
criteria. Maximum concentrations of chromium, thallium, and arsenic exceed screening criteria by a factor of
more than 15. All of these constituents are metals or other inorganics that do not degrade in the
environment.
• Lead, thallium, antimony, and arsenic concentrations exceed the ingestion criteria. This
indicates that, if the dust/sludge (or soil contaminated with the waste) is incidentally
ingested on a routine basis (e.g., if children are allowed to play on abandoned waste
piles) these constituents may cause adverse health effects. The concentration of arsenic
in the waste would pose a lifetime cancer risk greater than IxlO'5 if incidentally
ingested.
• Chromium and arsenic concentrations exceed the health-based screening criteria for
inhalation. This indicates that these constituents could pose a cancer risk greater than
IxlO"5 if dust were blown into the air and inhaled in a concentration that equals the
National Ambient Air Quality Standard for paniculate matter.
Exhibit 8-9
Potential Constituents of Concern in
Basic Oxygen Furnace APC Dust/Sludge Solids^
Potential
Constituent*
of Concern
Chromium
Lead
Thallium
Antimony
Arsenic
No. of Times
COnSUuiem
Detected/No, of
Analyse*
for Constituent
8/8
8/8
4t1
7/8
t/7
Human Health
Screening Criteria0*1
tohaJation*
Ingestion
tegesfen
Ingestion
ingestion*
tnQMuOR
No. of Analyse*
Exceeding Criteria/
No. of Analyses for
Constituent
8/8
8/8
4/7
5/8
t/7
1/7
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
6/6
6/6
zts
3/6
t/5
t/5
(a) Constituents listed In this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an **' are based on a IxlO"5 IHetime cancer
risk; others are based on noncancer effects.
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8-22 Chapter 8: Ferrous Metals Production
Exhibit 8-10
Potential Constituents of Concern in Basic Oxygen
Furnace APC Oust/Sludge Leachate^
Potential
Constituent*
of Concern
Zinc
Manganese
Cadmium
Iron
Molybdenum04
Lead
Selenium
Mercury
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
6/7
7/7
6/8
5/7
3/7
3/8
1 /8
5/8
Screening Criteria
Human Hearth
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
5/7
5/7
6/7
1 /7
7/7
1/7
3/8
5/8
5/8
3/7
1 /7
3/7
2/8
3/8
2/8
1/8
1/8
1/8
1/8
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
4/5
4/5
4/5
1 /5
5/5
1 /5
3/6
4/6
4/6
3/5
1 /5
3/5
2/6
2/6
2/6
1/6
1 /6
1 /6
1 /6
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. Unless otherwise
noted, the constituent concentrations used for this analysis are based on EP leach test results.
(b) Data for this constituent are from SPLP level test results.
Based on a comparison of leach test concentrations of 20 constituents to surface and ground-water
pathway screening criteria (see Exhibit 8-10), eight contaminants were detected at levels above the criteria.
All of these constituents are organics that do not degrade in the environment. Zinc, manganese, and cadmium
concentrations exceed screening criteria in most (62 to 100 percent) of the analyses, and their concentrations
in samples from at least two-thirds of the facilities analyzed exceed screening criteria. Maximum
concentrations of manganese and iron exceed screening criteria by factors of greater than 100, and maximum
concentrations of zinc, lead, and selenium exceed screening criteria by factors of greater than 10. Despite these
exceedances of the screening criteria, only selenium was detected in a concentration that exceeds the EP
toxicity regulatory level, and that was only in one sample.
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Chapter 8: Ferrous Metals Production 8-23
Previous EPA analyses also indicate that the pH of aqueous extracts of steel furnace APC dust/sludge
ranges from 5.4 to 12.5 standard units.15 This range, especially at the high end, is outside the acceptable
range established for drinking water and aquatic life protection.
The exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• Concentrations of zinc, manganese, cadmium, lead, and selenium in steel furnace APC
dust/sludge leachate exceed health risk (drinking water) screening criteria. This
indicates that, if dust/sludge leachate were released and diluted less than ten-fold during
migration to a drinking water exposure point, long-term ingestion could cause adverse
health effects due to the presence of these constituents.
• Zinc, manganese, cadmium, iron, lead, selenium, and mercury in the dust/sludge
leachate, as well as its alkalinity, could present a threat to aquatic organisms if it
migrates (with less than 100-fold dilution) to surface waters.
• Zinc, manganese, cadmium, iron, molybdenum, lead, and selenium in the APC dust/
sludge leachate, as well as its alkalinity, could restrict the potential future uses of af-
fected ground- and surface-water resources if released and diluted by a factor of 10 or
less.
These exceedances of the screening criteria, by themselves, do not prove that the dusts/sludges pose
significant risks, but rather indicate that the wastes could pose a risk under a very conservative, hypothetical
set of release, transport, and exposure conditions. To determine the potential for these wastes to cause
significant impacts, EPA proceeded to the next step of the risk assessment to analyze the actual conditions
that exist at the facilities that generate and manage the wastes.
Release, Transport, and Exposure Potential
This analysis considers the baseline hazards of blast furnace and steel furnace APC dust/sludge as they
were generated and managed at 17 plants in 1988. For this analysis, the Agency did not have sufficient data
to assess (1) the hazards of off-site use or disposal of the wastes, (2) risks associated with variations in waste
management practices or potentially exposed populations in the future, or (3) the hazards of alternative
management practices. However, alternative practices for the management of blast furnace and steel furnace
APC dust/sludge are discussed in Section 8.5. The hazards of off-site and alternative management practices
were also within the scope of the damage case investigation, presented in Section 8.3.3.
The Agency evaluated the potential hazards posed by the management of blast furnace and steel
furnace APC dust/sludges for only the facilities that provided information on on-site dust/sludge management
units in their responses to the National Survey of Solid Wastes from Mineral Processing Facilities. Of the 11
facilities that generate blast furnace APC dust/sludge but were not evaluated, 5 facilities responded that this
waste was sent off-site for disposal, 4 facilities stated that in 1988 all of this waste was recycled to process
units, and 2 facilities identified on-site management units containing this waste (i.e., a stockpile and a waste
pile) but provided no details on the characteristics of these units. Of the 15 facilities that generate steel
furnace APC dust/sludge but were not evaluated, 2 facilities identified on-site management units containing
this waste (i.e., a stockpile and a waste pile) but provided no details on the characteristics of these units, one
facility requested that all information in its survey be held confidential, and the other 12 facilities did not
provide information on the management of steel furnace APC dust/sludge. Because the management units
that are evaluated include both disposal units (e.g., landfills and ponds) and temporary storage units (e.g.,
storage pads and transfer areas), such as might be present at the facilities that recycle the waste or send it off-
site for disposal, EPA expects that the hazards at the facilities that are evaluated reflect the diversity and
15 EPA. 1979. Environmental and Resource Conservation Considerations of Steel Industry Solid Waste. Office of Research and
Development. EPA-600/2-79-074.
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8-24 Chapter 8: Ferrous Metals Production
nature of the potential threats posed by blast furnace and steel furnace APC dust/sludge at the other facilities
that generate these wastes.
Ground-Water Re/ease, Transport, and Exposure Potential
EPA and industry test data discussed above show that several constituents are capable of leaching
from blast furnace and steel furnace APC dust/sludge in concentrations that exceed the conservative screening
criteria. Considering the existing waste management practices and pH of the leachate, the only constituents
in blast furnace APC dust/sludge that are expected to be mobile in ground water if released are arsenic,
fluoride, selenium, mercury, cadmium, and chromium. Steel furnace APC dust/sludge contaminants that are
expected to be mobile if released include cadmium, molybdenum, selenium, and mercury. In addition, the pH
of APC dust/sludge leachate may threaten ground-water resources. Based on an evaluation of management
practices, hydrogeologic settings, and current ground-water use patterns, EPA concludes that the potential for
ground-water release, transport, and exposure ranges from low to fairly high at the 17 facilities.
The majority of the iron and steel production plants (12 of the 17 facilities evaluated) manage blast
furnace and steel furnace APC dust/sludge as a dry material in units such as stockpiles, landfills, waste piles,
and transfer areas. Ground-water release potential from these types of units is determined by the infiltration
of precipitation through the unit and into the underlying aquifer. Release, transport, and exposure potential
at the 12 facilities managing the sludge/dust in dry units varies according to the use of engineered controls that
limit infiltration, the nature of the subsurface geology, and the proximity of the management units to potential
drinking water exposure locations.
• Although the Rouge waste pile containing blast furnace APC dust/sludge and the dust
silo containing steel furnace APC dust/sludge are not equipped with liners or other
engineered controls to restrict releases to ground water, the plant has relatively low
ground-water contamination potential because the uppermost useable aquifer is
protected by an upper confining layer. Because the underlying aquifer is artesian (i.e.,
it has a hydraulic head higher than the surrounding land surface), this confining layer
is clearly an effective barrier to vertical ground-water flow.
• The Shenango plant temporarily stores blast furnace APC dust/sludge on a concrete-
lined pad. This pad may limit infiltration to some extent, but because the pad does not
have run-on/run-off controls to contain precipitation that falls on the pad or to limit
overland flow of stormwater onto the pad, constituents could be released from this pad
following precipitation events. Contaminants released from the pad could reach ground
water quite readily because net recharge to ground water in this area is relatively high
(18 cm/yr) and the aquifer is relatively shallow (3 meters). If contaminants from the
dust/sludge were to enter the aquifer, they could pose health risks to existing
populations via a public water supply well (serving 3,000 people) located 1,000 meters
downgradient from the facility.
• The Warren and Bethlehem/Burns Harbor plants manage the blast furnace and steel
furnace dust/sludge in landfills or piles with no engineered controls to limit ground-
water infiltration of waste leachate. The potential for contaminant releases to ground
water at these plants is moderate because net ground-water recharge is moderate to high
(10 to 28 cm/yr) and the aquifers lie 3 to 6 meters below the land surface. Releases
from the stockpile at the Warren plant may be limited somewhat by in-situ clay
underlying the unit. Any releases that might occur at the Warren plant could endanger
human health through drinking water exposures at a public supply well or private
residences, located from 460 to 1,100 meters downgradient.
• The remaining eight facilities that manage the blast furnace and steel furnace
dust/sludge in only landfills or piles (i.e., McLouth, LTV/East Cleveland, Beth-
lehem/Bethlehem, Bethlehem/Sparrows Point, USX/Fairfield, Gulf States, Inland, and
LTV/West Cleveland) also have moderate to relatively high release potential but pose
no current health risk via the ground-water pathway. The management units at these
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Chapter 8: Ferrous Metals Production 8-25
facilities have no engineered ground-water release controls, and the moderate to high
net recharge (8 to 20 cm/yr) where these facilities are located indicates a relatively high
potential for releases to ground water from dust/sludge management units. However,
ground water is not used as a source of drinking water within 1.6 km (1 mile)
downgradient of all eight of these facilities. Any significant releases from these units
could render ground-water supplies less desirable for use in the future.
Five facilities manage at least some blast furnace and steel furnace APC dust/sludge in impoundments.
Three of these facilities (i.e., ARMCO/Middletown, LTV/Indiana Harbor, and National/Granite City) manage
dust/sludges in both impoundments and dry units such as landfills and piles, and two facilities (i.e., Geneva
and USX/Lorain) manage the wastes in impoundments only. Ground-water release potential from
impoundments is a function of the permeability of the material lying between the impoundment and the
aquifer, and the hydraulic head provided by standing liquids in the impoundment. Release, transport, and
exposure potential at the five facilities that manage the sludge/dust in impoundments varies according to the
use of engineered controls designed to limit seepage or infiltration of precipitation, the nature of the
subsurface geology, and the proximity of the management units to potential drinking water exposure locations:
• The LTV/Indiana Harbor plant manages blast furnace APC dust/sludge in a sludge
storage area, a lagoon, and a landfill. None of these units have engineered ground-
water release controls such as liners or leachate collection systems. The potential for
releases to ground water from the lagoon is high due to the hydraulic head of the
standing water. For the other units, release potential is moderate because net recharge
is moderate (10 cm/yr), subsurface materials are comprised primarily of sand, and the
usable aquifer lies six meters below the land surface. There are no current uses of
ground water within 1.6 km (1 mile) downgradient of this facility. Consequently,
potential releases of dust/sludge contaminants would not pose current health risks but
could render the ground water unsuitable for potential future uses.
• Ground-water release potential is relatively high at the ARMCO/Middletown plant
because the dust/sludge management units (i.e., a landfill, two surface impoundments,
and a waste pile) have no engineered ground-water release controls such as liners or
leachate collection systems, and although in-situ clay underlies some of the units, the
subsurface material is relatively permeable. Potential releases of dust/sludge con-
taminants from these units could pose a current health risk via drinking water exposures
at a residence located 1,100 meters downgradient of the facility.
• Two of four dust/sludge management units at the National/Granite City plant have
engineered controls: the flue dust pond is equipped with primary and secondary
leachate collection systems, and the landfill has a synthetic liner. Releases from the
other two units at this facility (i.e., the stabilization basin and backwash pond) are not
controlled by any engineered features, but they may be limited somewhat by in-situ clay.
The potential for ground-water releases from these two impoundments (and the flue
dust pond and landfill, if the engineered controls should fail) is relatively high because
subsurface material at this plant is comprised largely of sand and the aquifer lies only
2~5 meters below the land surface. Any potential ground-water contamination at this
plant could restrict potential future uses but would not present a current health threat
(i.e., the aquifer is not used as a source of drinking water within 1.6 km [1 mile]
downgradient of this plant).
• The potential for releases from impoundments at the Geneva and USX/Lorain plants
is relatively high because the management units are not equipped with engineered
ground-water release controls and the subsurface material is moderately permeable. If
releas. were to occur from these units, ground water at both facilities might be
renderul unsuitable for future uses, and contaminated ground water at the Geneva
facility might also pose health risks from drinking water exposures at residences as close
as 90 meters from the facility.
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8-26 Chapter 8: Ferrous Metals Production
Surface Water Release, Transport, and Exposure Potent/at
Theoretically, constituents of potential concern in blast furnace and steel furnace APC dust/sludge
could enter surface waters by migration of dust/sludge leachate through ground water that discharges to surface
water, or by direct overland (stormwater) run-off of dissolved or suspended dust/sludge materials. The
presence of several constituents in blast furnace and steel furnace APC dust/sludge leachate in concentrations
that exceed the screening criteria confirms that the potential exists for contaminants from these wastes to
migrate into surface water in a leached form. The small size of dust/ sludge particles (ranging from less than
0.02 mm up to 2 mm) also indicates a high potential for overland release of these wastes to surface waters.
Panicles that are 0.1 mm or smaller in size tend to be appreciably credible16, and the Agency expects that
a significant fraction of the blast furnace and steel furnace APC dust/sludge is in this size range.
Based on environmental settings of the facilities, management unit characteristics, and the presence
of stormwater run-on/run-off controls at some of the blast furnace APC dust/sludge management units, the
potential for surface water contamination and human exposure due to releases from blast furnace and steel
furnace APC dust/sludge at the 17 facilities is as follows:
• The National/Granite City plant poses very little threat to surface water because of the
extreme distance (3300 meters) to the nearest surface water ~ the Mississippi River.
Contaminants that might enter the surface water after migrating over this great distance
would be diluted sufficiently that they would not pose a threat to any potential uses of
the water or to aquatic life.
• The ARMCO/Middletown, LTV/West Cleveland, and Geneva plants pose moderate
threats to surface water primarily via the discharge of contaminated ground water to
surface waters. Transport of dust/sludge constituents to surface waters from units at
these facilities may be limited by the relatively large distance (i.e., 240 to 370 meters)
to the nearest surface waters, the use of run-off controls to limit stormwater release
from some of the units at the ARMCO and LTV plants, and the small likelihood that
sludge managed at the bottom of the impoundment in Geneva could be released to
surface water via erosion. As discussed above, however, the potential for ground-water
contamination at these facilities is moderate to high and ground-water discharging to
surface water may pose threats to aquatic life and potential uses of the nearby surface
waters. In addition, if not sufficiently diluted, releases from the LTV/West Cleveland
plant could contaminate a drinking water intake located 23 km downstream of the plant.
• APC dust/sludge management at the remaining facilities poses a relatively great threat
to surface water by both ground-water discharge to surface water and overland erosion
of dust/sludge particles. Release potential from these facilities is high because (1) some
of the units at these facilities do not have run-off controls to restrict the erosion and
overland transport of dust/sludge particles in stormwater and (2) all these facilities are
located less than 200 meters from nearby surface waters. The LTV/East Cleveland,
Bethlehem/Sparrows Point, Bethlehem/Bethlehem, Shenango, and Rouge plants present
additional hazards because they are located in 100-year floodplains and may release
large amounts of contaminants to surface waters in flood events. Aquatic life and
potential water uses are threatened from releases to surface waters at all of these plants.
These risks are greatest at the USX/Fairfield, Gulf States, LTV/East Cleveland, and
Rouge facilities where the receiving water bodies are relatively small (i.e., 70 to 600
mgd). Surface water contamination at the Rouge, Bethlehem/Burns Harbor,
LTV/Indiana Harbor, and USX/Lorain plants, if not sufficiently diluted, could pose
current health threats via drinking water supply intakes located 10 km, 19 km, 4 km, and
0.5 km downstream from these facilities. These intakes provide drinking water for 1.2
million; 230,000; 93,400; and 75,000 people, respectively.
16 As indicated by the soil credibility factor of the USDA's Universal Soil Loss Equation.
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Chapter 8: Ferrous Metals Production 8-27
Air Release, Transport, and Exposure Potential
Because all of the constituents of potential-concern are nonvolatile, blast furnace and steel furnace
APC dust/sludge contaminants can only be released to air in the form of dust particles. Dust can be either
blown into the air by wind or suspended in air by waste dumping operations. Factors that affect the potential
for such airborne releases include the particle size of the dust/sludge, the height and exposed surface area of
the waste management unit, the moisture content of the waste as it is managed, the use of dust suppression
controls, and local wind speeds. The potential for exposure to airborne dust depends on the proximity of the
waste management units to people.
In general, particles that are less than 0.1 mm in diameter are wind suspendable and transportable.
Within this range, however, only particles that are less than 0.03 mm in diameter can be transported for
considerable distances downwind, and only particles that are less than 0.01 mm in diameter are respirable.
A significant portion of APC dust/sludge particles are small enough to be wind suspendable and some fraction
of the suspendable particles consists of smaller particles that can be respired. As discussed above, blast
furnace dust/sludge contains arsenic, chromium, and cadmium at concentrations that exceed the screening
criteria for inhalation.
APC dust/sludge is managed as dry material that is vulnerable to wind erosion at 15 of 17 facilities.
Air pathway risks are expected to be minimal at the two facilities (i.e., Geneva and USX/Lorain) that manage
APC dust/sludge in impoundments only. Based on consideration of environmental conditions, management
unit characteristics, and distance to potential exposure points, the Agency concludes that air pathway release,
transport, and exposure potential varies considerably among the 15 facilities that manage APC dust/sludge in
dry units such as landfills and piles.
• Six facilities (McLouth, National/Granite City, Gulf States, LTV/East Cleveland, Beth-
lehem/Sparrows Point, and Rouge) practice dust suppression at all units other than
impoundments used to manage blast furnace APC dust/sludge. If dust suppression
practices are not effective, or are stopped for any reason, the potential for dust to be
released from these units is relatively high because of the large size of the units at some
of these facilities (up to 75 acres) and the large number of dry days each year (230 to
270) when APC dust could be released to the atmosphere. If releases occur, there is
significant potential for human exposure at nearby residences (15 to 530 meters
downwind). The population within 1.6 km (1 mile) of these facilities ranges from 2,000
to 25,000 people.
• Bethlehem/Burns Harbor and V&rren practice dust suppression at some of the units
used to manage APC dust/sludge. Releases from dry units at these facilities (a total
surface area of 9 hectares (21 acres) at Burns Harbor and 1.3 hectares at V&rren) could
present inhalation risks for residents living as close as 530 and 100 meters from the
Burns Harbor and Wirren facilities, respectively. A total of 100 people live within 1.6
km (1 mile) of the Burns Harbor plant and 20,000 people live within 1.6 km of the
Wuren plant, and could be exposed to airborne contaminants released from APC
dust/sludge management units that are dry.
• Seven iron and steel production plants (i.e., Shenango, USX/Fairfield, ARMCO, Inland,
LTV/West Cleveland, Bethlehem/ Bethlehem, and LTV/Indiana Harbor) do not practice
dust suppression at units used to manage APC dust/sludge. Given the large exposed
surface areas of these units (0.08 to 140 hectares) and the large number of dry days each
year (250 to 270) when APC dust could be released to the air, the potential for releases
of contaminants to the air pathway is relatively high at these facilities. Releases of
airborne contaminants could pose human health threats to residents living as close as
15 to 400 meters from these facilities. The total population that might be exposed to
airborne contaminants within 1.6 km of these facilities ranges from 3,200 to 20,000
people.
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8-28 Chapter 8: Ferrous Metals Production
Proximity to Sensitive Environments
As discussed in Section 8.3.1 above, 23 of 26 iron production facilities and 21 of 26 steel production
facilities are located in or near environments that are vulnerable or environments that have high resource
value (see the discussion in Section 8.3.1).
Risk Modeling
Based upon the evaluation of intrinsic hazard and the descriptive analysis of factors that influence risk
presented above, and upon a comprehensive review of information on documented damage cases (presented
in the next section), EPA has concluded that the potential for blast furnace and steel furnace slag and APC
dust/sludge to pose significant risk to human health or the environment, if managed according to current
practice, is low at most facilities but moderate to high at others. This conclusion that the risks are low at most
facilities is supported by the Agency's modeling results for other mineral processing wastes that appear to pose
a greater hazard than the ferrous wastes, as well as the lack of damage cases (as outlined in the next section).
Therefore, in accordance with the risk assessment methodology outlined in Chapter 2, the Agency has not
conducted a quantitative risk modeling exercise for these wastes. Section 8.3.4 below discusses the basis for
the assessment of the hazard of these wastes in more detail.
8.3.3 Damage Cases
The Agency reviewed State and EPA regional files in an effort to document the performance of slag
and APC dust/sludge waste management practices at the active iron and steel facilities, as well as at the
following inactive facilities:17
US Steel (USX)
• National Works, McKeesport, Allegheny County, PA
• West Mifflin Works (Brown's Dump), West Mifflin, Allegheny County, PA
• Taylor Landfill, West Mifflin, Allegheny County, PA
• Vandergrift Plant, Vandergrift, Westmoreland County, PA
• Clairton Works, Clairton, Allegheny County, PA
• Carrie Furnace, Rankin, Allegheny County, PA
• Imperial Works, Oil City, PA
• Homestead (Carrie Furnace), Rankin, PA
• Irvin Plant, West Mifflin, Allegheny County, PA
LTV Steel
• Aliquippa Works (Crows Island/Blacks Run Creek Residual Site) Aliquippa, Beaver County,
PA
Bethlehem Steel
• Steelton, PA
• Johnstown, Cambria County, PA
• Riders Disposal Area, East Taylor Township, Cambria County, PA
• Chesterton, IN
17
Facilities are considered inactive for purposes of this report if they are not currently engaged in primary mineral processing.
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Chapter 8: Ferrous Metals Production 8-29
The file reviews were combined with interviews with State and EPA regional regulatory staff.
Through these case studies, EPA found documented environmental damages associated with the wastes of
concern for only one facility, LTV Steel's Aliquippa Works, in Aliquippa, Pennsylvania.
LTV Steel, Aliquippa, Pennsylvania.
The Jones and Laughlin Steel Corporation (J&L, or LTV Steel) Aliquippa Works, also known as
Crow Island, is located in Beaver County, Pennsylvania, along the Ohio River. The Aliquippa Works, no
longer an operating facility, was shut down in about 1985.18 When operational, the Aliquippa facility
contained both blast furnace and basic oxygen furnace operations.19 The Aliquippa facility is located in the
flood plain of the Ohio River. The average ground elevation (735 ft Mean Sea Level) is about 15 meters (50
feet) above the normal pool elevation of the Ohio River. At least five private drinking water wells are within
0.8 km (1/2 mile) of an on-site landfill.
Documented environmental impacts have occurred in two general areas of the site. The first area is
the Black's Run Landfill, which is lined with basic oxygen furnace slag; leachate from this landfill has entered
Black's Run Creek. The second area is the Aliquippa Works facility itself. At least a portion of the facility
is underlain by blast furnace slag, which has a thickness of 16 meters (52 feet) in some places.20 This blast
furnace slag is contaminating shallow ground water that seeps into surface water.
The Black's Run area has served as a storage and disposal site for over 40 years. In 1980, J&L
commenced operation of a RCRA Subtitle C landfill within the Black's Run site for disposal of certain
designated hazardous wastes generated by J&L in the iron- and steel-making processes. The primary
hazardous waste disposed at Black's Run was and is air pollution-control dust from electric arc steelmaking
furnaces at J&Es Cleveland and Pittsburgh Works.21-22^
The disposal cell was lined with multiple layers: a two foot layer of basic oxygen furnace slag, covered
with one and one half feet of low permeability flyash, and topped with a three foot layer of slag. The landfill
was constructed on a slope, directing leachate downward to be collected and treated at the 'toe' of the
slope.24
EPA did not find information on concentrations of metals or other toxic pollutants for either area,
but information several conventional water quality parameters was available.
Basic Oxygen Furnace Slag
By 1982, Pennsylvania Department of Environmental Regulation (PADER) investigators found
indications that leachate from the landfill was discharging into the East Fork of Black's Run Creek, and that
a white precipitate had been deposited on the stream bottom downstream of the landfill. The inspector
reported that the leachate was apparently not from the electric furnace dust and sludge, but rather from the
18 USEPA, Region 111. 1985. Letter to LTV Steel, Aliquippa, Re Application for Pott-Closure Permit, EPA LD. No. PAD 00 080
5028.
19 Jones and Laughlin Steel. 1981. Black's Run Disposal Site Facility Description. 8/27/81.
20 LTV Steel. 1980. Hydrogeologic Investigation of Number 18 Well Ammonia Contamination, prepared by The Chester Engineers.
August, 1980.
21 LTV Steel, Aliquippa. 1980. General public news release on Black's Run Secure Landfill. 11/20/80.
22 Jones and Laughlin Steel. 1981. Black's Run Disposal Site Facility Description.
23 LTV Steel, Aliquippa. 198Z Form filled for PADER: Request for Approval to Treat, Store, or Dispose of a Hazardous or
Residual Waste Stream. 8/25/82.
24 PADER. 1982. Bureau of Solid Waste Management Memo, from S. McDougall to V. Luci. Re Jones and Laughlin Steel
Corporation, Aliquippa Works, Blacks Run Disposal Site, RCRA Well Proposal Review, and General Site Comments. 12/29/82.
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8-30 Chapter 8: Ferrous Metals Production
slag and ash liner.25 This white deposit, attributed to the slag liner, was noted in 1987 and 1988 as
well.26-27
The landfill was closed in September 19?". because its slag liner did not meet the revised standards
for an operating permit. Closure activities invol' .• J regrading, capping with a clay/soil layer, and securing the
area with a fence.28 Monitoring wells were installed around the landfill at depths to monitor both the
shallow aquifer and a deeper aquifer.29
Samples taken in March 1987 show Black's Run Creek upstream of the landfill at a pH of 8.43, and
total dissolved solids (TDS) at 597 mg/1. Downstream of the landfill, the pH of Black's Run was elevated to
12.30 and TDS to 1,925 mg/1. Monitoring well sampling on this same date showed a significant increase in
pH from the upgradient shallow well at a mean of 7.71 to the downgradient shallow well at a mean of 9.29,
exceeding the National Secondary Drinking \\fcter Regulations maximum pH level of 8.5. Analytical data for
parameters other than pH and TDS were not contained in the available documents.30
In a June 1988 inspection report, the FADER inspector noted that visible impacts to the Black's Run
Creek occurred much farther downstream than when they had been first noted several years previously. The
inspector found the creek bottom covered with precipitate for approximately 460 meters (500 yards)
downstream. The PADER inspector also stated that little aquatic life was evident in the creek from the point
where it passed the landfill until well below all the seeps, close to where the stream goes under Route 51.
Another inspector in June 1988 found erosion problems on the soil cap of the closed landfill, and an
unsatisfactory revegetation status.31'32'33
Blast Furnace Slag
As mentioned previously, the Aliquippa Works facility itself was constructed on blast furnace slag fill,
which is at least 16 meters (52 feet) thick in some places.34*35
25 ibid.
^PADER. 1987. Bureau of Waste Management, Hazardous Waste Inspection Report, TSD Facilities. LTV Steel Blacks Run Creek
Secure Cell, Aliquippa, Beaver County. 11/6/87.
27 PADER. 1988. Bureau of Solid Waste Management, General Inspection Form. LTV Steel - Blacks Run Creek Residual Site,
Aliquippa, PA. 6/2/88.
28 PADER. 1990. Personal Communication with C Spadero.
29 PADER. 1988. Bureau of Waste Management, Comments on closure of LTV Blacks Run site, Aliquippa. (9/23/86 and 7A/88.)
30 LTV Steel. 1987. Letter with attachments to PADER, Re: Black's Run Secure Landfill Groundwater Monitoring Data and
Statistical Analysis, Tenth Quarter (1st Quarter, 1987), Aliquippa Works, Aliquippa, PA 7/24/87.
31 PADER. 1988. Bureau of Solid Waste Management, General Inspection Form. LTV Steel - Blacks Run Creek Residual Site,
Aliquippa, PA 6/2/88.
^PADER. 1988. Bureau of Waste Management, Hazardous Waste Inspection Report, TSD Facilities. LTV Steel Blacks Run Creek
Secure Cell, Aliquippa, Beaver County. 6/10/88.
33 PADER. 1988. Bureau of Waste Management, Comments on closure of LTV Blacks Run site, Aliquippa. (Includes 9/23/86 and
7A/88.).
34 LTV Steel. 1980. Hydrogeologic Investigation of Number 18 Well Ammonia Contamination, prepared by The Chester Engineers.
8/80.
35 LTV Steel. 1988. Letter to USEPA Region III and PADER, Re: NPDES Permit No. PA 0006114: November, 1988 Monitoring
Results. 12/27/88.
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Chapter 8: Ferrous Metals Production 8-31
In a cover letter for monitoring data submitted by LTV to PADER, LTV discussed elevated pH and
TDS values in seep samples, stating that such values "are not unexpected from areas where the slag was placed
for fill." Analytical data from these seeps from 1977 through 1985 showed pH values ranging from 12.1 to
13.1, while TDS values ranged from 1370 mg/1 to 3508 mg/1.36
In a letter to PADER in December 1987, LTV discussed its NPDES violations. LTV reported two
outfalls discharging water with pH values of 10.9 and 10.4, exceeding the maximum permitted pH of 9.0. LTV
explained that "the fill in the area of the two outfalls is all blast furnace slag. This would cause high pH in
rainwater entering the now idled sewers."37
LTV's November 1988 NPDES monitoring results submitted to PADER indicated an exceedance of
the maximum permitted pH level of 9.0 in an outfall with pH 9.4. LTV again explained that the Aliquippa
Works is built on slag fill. LTV noted that since no operating facility uses the sewer of concern, ground water
from the slag filled areas was probably infiltrating the sewers and causing the high pH.38
8.3.4 Findings Concerning the Hazard Posed by Special
Wastes from Ferrous Metals Production
Based upon the detailed examination of the inherent characteristics of iron blast furnace and steel
furnace slags and APC dusts/sludges, the management practices that are applied to these wastes, the
environmental settings in which the generators of the materials are situated, and the documented
environmental damages that have been described above, EPA concludes that these wastes pose a low to
moderate risk to human health and the environment.
Blast Furnace and Steel Furnace Slag
Review of the available data on blast furnace and steel furnace slag solid sample and leachate
constituent concentrations indicates that only seven constituents are present at concentrations greater than
10 times conservative screening criteria. In blast furnace slag, concentrations of manganese, iron, lead, arsenic,
and silver exceed screening criteria by more than a factor of 10. Concentrations of manganese, iron,
chromium, thallium, and arsenic in steel furnace slag exceed one or more of the conservative screening criteria
by more than a factor of 10. In addition, aqueous extracts of both blast furnace and steel furnace slag are
highly alkaline (pH up to 11.7). These exceedances indicate the potential for the slags to pose risks under very
conservative, hypothetical exposure conditions. The wastes do not exhibit any of the four characteristics of
a hazardous waste, and the actual exposure conditions at the active facilities are not as conducive to human
health or environmental damage as those upon which the screening criteria are based. This is largely because
the slags consist of large solid fragments that are not readily released and dispersed. This finding leads EPA
to conclude that the intrinsic hazard of these slags is low.
Based on a review of the site-specific conditions at 11 facilities, the potential for blast furnace and
steel furnace slag to cause significant impacts appears low at most of the active facilities. The potential for
significant releases to ground water is often limited by a low net recharge and a large depth to ground water.
The potential for significant surface water impacts is limited by the large particle size of the slag (which
precludes erosion) as well as the large distances to water bodies, large surface water flow rates, and great
downstream distances to potential receptors at many sites. The large particle size of the slag also limits the
potential for significant airborne releases. This overall low-risk conclusion is supported by the general lack
36 LTV Steel. 1985. Letter with attachments to PADER, Re LTV Steel Company, Inc. (Jona and Laughlin Steel, Inc.) Aliquippa
Works - Crow Island Site. 8/27/82.
37 LTV Steel. 1987. Letter to PADER, Bureau of Water Quality, Re: NPDES Permit PA 0006114, Pollution Reduction Report, LTV
Steel Co., Beaver County. 12/2/87.
38 LTV Steel. 1988. Letter to USEPA, Region III and PADER, Re: NPDES Permit No. PA 0006114: November, 1988 Monitoring
Results. 12/27/88.
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8-32 Chapter 8: Ferrous Metals Production
of documented cases of damage attributable to the slags. Even though the slags have been generated and
managed at many sites for several decades, EPA identified only one damage case and that case is associated
with an inactive facility under rather unusual conditions (i.e., the slag was used as a liner for a hazardous waste
landfill). EPA believes that the management controls and environmental conditions at a few of the active
facilities are, in theory, also favorable for contaminant releases to ground and surface water, but no releases
are known to have occurred at these sites in the past.
Blast Furnace and Steel Furnace APC Dust/Sludge
Review of the available data on blast furnace and steel furnace APC dust/sludge solid samples and
leachate concentrations indicates that a number of constituents are present at concentrations that exceed the
conservative screening criteria. Concentrations of 12 constituents in blast furnace APC dust/sludge exceed one
or more of the conservative screening criteria by more than a factor of 10. In steel furnace APC dust/sludge,
manganese, iron, zinc, lead, selenium, chromium, thallium, and antimony concentrations exceed one or more
of the conservative screening criteria by more than a factor of 10. In addition, aqueous extracts of both blast
furnace and steel furnace APC dust/sludge are highly alkaline (pH up to 12.5). While releases and exposures
are generally not expected to be as large as the hypothetical conditions upon which the screening criteria are
based, the dusts/sludges consist of small panicles that could be released to the environment if not properly
controlled. The available data also indicate that some blast furnace APC dust/sludge at some facilities exhibits
the characteristic of EP toxicity, but that steel furnace APC sludge probably is not EP toxic (although the
selenium concentration in one sample did exceed the regulatory level by a factor of 1.46). As a result, EPA
believes that the intrinsic hazard of these wastes is moderate to high.
Based on an examination of the site-specific conditions at 17 facilities, the current management of
blast furnace and steel furnace APC dust/sludge poses a low threat at some facilities but a moderate to high
threat at others. In general, the potential for the dust/sludge to cause significant ground-water impacts is
limited at most sites that manage the waste in a dry form (in stockpiles, landfills, waste piles, etc.) because of
the low net recharge, depth to ground water, and/or distance to potential receptors. When managed in
impoundments, however, there is a considerably greater potential for the dust/sludge contaminants to migrate
into ground water. EPA believes that the potential for dust/sludge contamination to migrate into surface water
is high at 13 of the facilities because of the wastes's small particle size, a lack of engineered controls to limit
releases, and a close proximity to surface water bodies. However, contaminants entering rivers near all but
four of these facilities are likely to be readily assimilated by the rivers' large flow. Considering the
susceptibility of the dust/sludge to wind erosion, the exposed surface area of waste management units, the lack
of dust suppression controls, atmospheric conditions, and population distributions, there is also a relatively
high potential for airborne releases and exposures at seven facilities. Despite these theoretical conclusions
about potential hazards, EPA did not identify a single case of environmental degradation that can be attributed
to the dust/sludge. Therefore, considering the site-specific conditions together with the lack of damage cases,
EPA concludes that the dust/sludge poses an overall moderate risk.
8.4 Existing Federal and State Waste Management Controls
8.4.1 Federal Regulation
Under the Clean Water Act, EPA has the responsibility for setting "effluent limitations," based on
the performance capability of treatment technologies. These "technology based limitations" which provide the
basis for the minimum requirements of NPDES permits, must be established for various classes of industrial
discharges, including a number of mineral processing categories.
Permits for mineral processing facilities may require compliance with effluent guidelines, based on
the best practicable control technology currently available (BPT) or best available technology economically
achievable (BAT). These limitations do not apply to non-point sources, such as run-off from slag piles, or
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Chapter 8: Ferrous Metals Production 8-33
impoundments containing APC sludges and dusts. BPT effluent limitations (40 CFR 420.32(a)) for discharges
of wastewater from iron blast furnace slags include:
Pollutant
Ammonia
Cyanide
Phenols
Dally Maximum
0.161 Kg/kkg
0.0234 mg/1
0.00626 mg/I
Monthly Average
0.0537 mg/I
0.00782 mg/1
0.00210 mg/I
For BAT, the following effluent limitations, found at 40 CFR 420.33(a), apply to discharges from iron blast
furnaces:
Pollutant
Ammonia
Cyanide
Phenols
Dally Maximum
1.29 mg/I
0.469 mg/I
0.0624 mg/I
Monthly Average
0.429 mg/1
0.156 mg/I
0.0208 mg/1
The discharge of wastewater pollutants from any new source of iron blast furnace slag may not exceed
the following (40 CFR 420.34(a)):
Pollutant
Ammonia
Cyanide
Phenols
Lead
Zinc
Dally Maximum
0.00676 mg/I
0.000584 mg/I
0.0000584 mg/1
0.000263 mg/1
0.00394 mg/1
Monthly Average
0.00292 mg/I
0.000292 mg/I
0.0000292 mg/1
0.0000876 mg/I
0.000131 mg/I
EPA has also established BPT and BAT effluent limitations resulting from steelmaking operations
conducted in basic oxygen and open hearth furnaces. BPT effluent limitations allow no discharge from semi-
wet BOF steelmaking. BPT limitations for steel-making operations for which wastewater discharges are
allowed include (40 CFR 420.42(b),(c»:
BASIC OXYGEN FURNACE - WET-SUPPRESSED COMBUSTION
Pollutant
Total Suspended Solids
pH
Dairy Maximum
0.0312 Kg/kkg
6-9
Monthly Average
0.0104 Kg/kkg
6-9
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8-34 Chapter 8: Ferrous Metals Production
BASIC OXYGEN FURNACE - WET-SUPPRESSED COMBUSTION AND
OPEN HEARTH FURNACE - WET
Pollutant
Total Suspended Solids
pH
Dally Maximum
0.0687 Kg/kkg
6-9
Monthly Average
0.0229 Kg/kkg
6-9
BAT effluent limitations allow no discharge from semi-wet EOF steelmaking (40 CFR 420.43(a)).
BAT limits for wastewater discharges from other processes include (40 CFR 420.43 (b),(c)):
BASIC OXYGEN FURNACE - WET-SUPPRESSED COMBUSTION
Pollutant
Lead
Zinc
Dally Maximum
0.000188 Kg/kkg
0.000282 Kg/kkg
Monthly Average
0.0000626 Kg/kkg
0.0000939 Kg/kkg
BASIC OXYGEN FURNACE - WET-SUPPRESSED COMBUSTION AND
OPEN HEARTH FURNACE - WET
Pollutant
Lead
Zinc
Dally Maximum
0.000413 Kg/kkg
0.000620 Kg/kkg
Monthly Average
0.000138 Kg/kkg
0.000207 Kg/kkg
New source standards for discharges include (40 CFR 420.44 (b),(c)):
BASIC OXYGEN FURNACE - WET-SUPPRESSED COMBUSTION
Pollutant
Total Suspended Solids
Lead
Zinc
pH
Daily Maximum
0.0146 Kg/kkg
0.000188 Kg/kkg
0.000282 Kfl/kkg
6-9
Monthly Average
0.00522 Kg/kkg
0.0000626 Kg/kkg
0.0000939 Kg/kkg
6-9
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Chapter 8: Ferrous Metals Production 8-35
BASIC OXYGEN FURNACE • WET-SUPPRESSED COMBUSTION AND
OPEN HEARTH FURNACE • WET
Pollutant
Total Suspended Solids
Lead
Zinc
pH
Dally Maximum
0.0321 Kg/kkg
0.000413 Kg/kkg
0.000620 Kg/kkg
6-9
Monthly Average
0.01 15 Kg/kkg
0.000138 Kg/kkg
0.000207 Kg/kkg
6-9
8.4.2 State Regulation
The 28 facilities generating blast furnaces slag, steel furnace slag, blast furnace APC dust and sludge,
and/or steel furnace APC dust and sludge are located in ten states, including Alabama, Illinois, Indiana,
Kentucky, Maryland, Michigan, Ohio, Pennsylvania, Utah, and West Virginia. Five of these states, Indiana,
Kentucky, Ohio, Pennsylvania, and Utah, were selected for detailed review for the purposes of this report (see
Chapter 2 for a discussion of the methodology used to select states for detailed study). Within the five study
states, the majority of facilities are located in Ohio (seven), Pennsylvania (six), and Indiana (four). Based on
the distribution of facilities within the five study states, state-level regulation of ferrous metal production
facility wastes is of particular interest in the States of Ohio and Pennsylvania.
Each of the ten states with one or more ferrous metal production facilities have adopted the federal
Mining Waste Exclusion and therefore do not regulate any of the four special wastes from ferrous metal
production as hazardous wastes. Three of the five study states, Ohio, Indiana, and Utah, do not regulate iron
or steel slag within their solid waste regulations. None of theltates appear to regulate slag stored on-site for
eventual recycling or reprocessing. APC dust and sludge may be shipped to permitted landfills, although this
is not regularly required by state regulation. Limited requirements are imposed on dust and sludge disposed
on-site. Requirements for NPDES permits and run-on/run-off controls vary by state and by facility in each
state. Similarly, requirements for fugitive dust controls vary by state regulation and facility location. In
contrast to the limited nature of current regulatory efforts, Ohio and Indiana recently promulgated new solid
waste regulations; Kentucky is finalising new regulations; Pennsylvania recently proposed new residual waste
regulations; and Utah recently passed new ground-water legislation. The increasing regulation of ferrous
wastes in each of these states could significantly affect the management of ferrous wastes, particularly APC
dust and sludge.
Seven ferrous metal production facilities are located in Ohio. The Ohio Solid Waste Disposal
Regulations state that slag is not a waste. The re-use of slag, however, may be subject to certain requirements.
Ohio does regulate APC dust and sludge as a solid waste. Facilities generating APC dust and sludge must
either obtain a permit to dispose of this waste on-site or ship the waste to a permitted landfill off-site.
According to state officials, only one of the seven facilities in the state has a permit for on-site disposal while
the remaining facilities either store the dust and sludge indefinitely for recycling or ship it off-site for disposal.
State officials were not able to provide details on the final disposition of much of the waste. Regulatory
controls of these wastes, until the recent promulgation of new solid waste regulations, appear to have been
limited. The recently amended regulations, however, require owners and operators of all landfills, including
on-site APC dust and sludge landfills, to apply for a permit and meet a variety of technical criteria (e.g.,
removal of free liquids, establishment of ground-water monitoring, placement of a final cap, provision of
financial assurance). Finally, although NPDES permits are required for discharges to waters of the state and
permits are required for landfills with fugitive dust emissions, Ohio does not appear to apply these
requirements to ferrous slag piles or surface impoundments.
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8-36 Chapter 8: Ferrous Metals Production
Ferrous metal production slags and APC dust and sludges are not regulated as either hazardous or
solid wastes by Pennsylvania. Instead, the state currently regulates ferrous wastes as "residual wastes." A
proposed rule regulating residual wastes would require a substantial expansion in the scope of the management
controls for slag and APC dust and sludge. The current residuals rule imposes only limited permitting
requirements. For instance, although waste piles used for permanent disposal must be permitted under current
state residuals regulations, Pennsylvania effectively has not implemented this requirement for slag piles because
of disagreements with industry on the status (Le., storage versus disposal) of the waste. Similarly, the state
applies surface water and air (i.e., fugitive dust control) requirements on ferrous metal production waste
management activities on a case-by-case basis and generally in response to complaints or evidence of
contamination only. Although the proposed rule would impose notably more stringent environmental controls
on the management of ferrous wastes, the final status of these wastes and the exact nature of additional
environmental controls will depend on the final rule.
Indiana does not regulate the "legitimate use of iron and steelmaking slags..." Indiana classifies APC
dust and sludge, however, as a special waste and requires that waste shipped off-site be sent to a designated
landfill meeting the technical criteria for special wastes. Owners and operators disposing of APC dust and
sludge on-site were not required to meet special landfill standards until the state modified its regulations in
1989. Three of the four facilities in the state have submitted permit applications to continue on-site disposal,
but it is not yet clear what kinds of technical requirements the state may impose in response to these
applications. Surface water and air discharge controls are addressed by the state on a facility-specific basis and
generally have been limited in scope. The extent of waste management requirements for ferrous wastes
remains somewhat unclear because the state's regulatory program implementation efforts have not been
completed.
One ferrous metal production facility is located in Kentucky. Kentucky requires some environmental
controls (e.g., maintaining a temporary cover, run-on/run-off controls, and drainage ditches) for on-site slag
disposal piles, but these requirements do not apply to slag that is reprocessed or sold. The state also requires
that the "residential" landfill to which the APC dust and sludge is shipped meet ground-water monitoring
criteria. Kentucky imposes effluent discharge limits on all iron and steel plant discharges, and imposes
extensive fugitive dust emission controls on slag management activities including watering of slag as it is
generated, "quenching" of trucks transporting slag, and transportation of slag on oiled roads. Kentucky
recently finalized its solid waste regulations and may impose more stringent environmental controls on the
management of slags and APC dusts and sludges at the ferrous facility, although the extent of the requirements
cannot be predicted until the regulations are implemented.
The state of Utah also has one ferrous metal production facility. In contrast to Kentucky, however,
Utah does not address either ferrous metal production slags or APC dusts and sludges under its solid waste
regulations. Utah recently enacted new ground-water legislation which mandates that all ground-water
discharges be permitted, though the state has not yet issued such permits. Moreover, although Utah has
paniculate matter air emissions regulations, it is not clear to what extent controls are required for ferrous
waste management (in particular, slag) at this facility.
In summary, ten states generate ferrous metal production slags and/or APC dust and sludges, of which
five states were studied in detail for this report The five study states regulate ferrous metal production wastes
similarly in a number of respects. For the most part, iron and steel slag management is currently subject to
limited solid waste regulation in these states, although in some cases waste slag is disposed of in a permitted
landfill. Although the management and disposal of APC dust and sludge has also been subject to limited
regulatory controls, these wastes are landfilled by facilities in several states and thus subject to all pertinent
regulations governing landfills in those states. Moreover, APC dust and sludge, as a rule, is regulated more
frequently than slag by the five study states. Finally, four of the five study states recently published final or
proposed waste regulations, while the fifth state recently enacted new ground-water protection legislation, all
of which could affect significantly the kinds and stringency of environmental controls imposed by the states
on ferrous metal production waste management and disposal activities.
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Chapter 8: Ferrous Metals Production 8-37
8.5 Waste Management Alternatives and Potential Utilization
Iron Blast Furnace Slag
As discussed above, EPA does not believe that iron blast furnace slag exhibits any of the four
characteristics of hazardous waste (corrosivity, reactivity, ignitability, or EP toxicity). Consequently, the issue
of how iron producers might modify their operations, waste management practices, or be stimulated to develop
alternative uses for iron slag in response to prospective hazardous waste regulation under RCRA Subtitle C
is moot. Any such operational changes that are currently contemplated by facility operators will therefore not
be affected by EPA's actions, and hence, are beyond the scope of this Report to Congress. Nonetheless, in
the following paragraphs, the Agency provides a brief summary of current and potential areas of utilization.
In 1988, nearly 18.8 million metric tons of iron blast furnace slag were generated by 26 U.S. iron
processing facilities.39 On-site accumulation at the 26 facilities ranges from 0 to 10 million cubic meters (0
to 13 million cubic yards), with a total accumulation of over 14.6 million cubic meters in active waste
management units.40 The facility which has accumulated 10 million cubic meters of slag, Inland Steel in East
Chicago, is placing it in Lake Michigan in order to create land on which additional waste can be disposed.41
Surveys of slag processors nationwide indicate that 14.4 million metric tons of slag were sold and/or used in
the United States in 1988 at an average price of $6.97 per ton.42 Some of this slag was retrieved from slag
piles at abandoned facilities.
According to a Bureau of Mines survey, 90 percent (16.9 million metric tons) of the iron blast furnace
slag utilized in 1988 was air-cooled. Air-cooled slag was sold at an average price of $4.87 per ton, ranging
from an average of S3.29 when sold for use as fill to an average of $9.87 when sold as material for built-up
and shingle roofing. Distribution of air-cooled slag among its various applications is shown in Exhibit 8-11.
Exhibit 8-11
Uses of Air-Cooled Iron Blast Furnace Slag43
Road base
Concrete aggregate
Fill
Asphaftic concrete aggregate
Railroad ballast, mineral wool, concrete products, glass
manufacture, sewage treatment, roofing, and soil
conditioning
57%
12%
10%
7%
14%
Company Responses to the "National Survey of Solid Wastes from Mineral Processing Facilities," VS. EPA, 1989.
41 Personal communication, Judith F. Owens, Physical Scientist, U.S. Bureau of Mines, Branch of Ferrous Metals, April 24, 1990.
42 Judith F. Owens, "Slag-Iron and Steel," Minerab Yearfaook-1988. U.S. Department of the Interior, Bureau of Mines, 1988, p. 2.
43 Ibid, p.5
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8-38 Chapter 8: Ferrous Metals Production
The remaining 10 percent (1.8 million metric tons) of iron blast furnace slag utilized in 1988 was comprised
of expanded slag, which is primarily used as a light-weight concrete aggregate, and granulated (water-cooled)
slag, most of which is used in the manufacture of Portland cement and other cementitious materials. Of the
iron blast furnace slag generated in the U.S., the Bureau of Mines indicates that nearly all of it is eventually
utilized.44
In the future, most primary iron producers in the U.S. are expected to modernize their blast furnaces
and install slag granulation facilities. If such a change does occur, it is likely to result in more slag being used
to manufacture Portland cement, and less slag being utilized as aggregate or road base. There has also been
some speculation about using iron blast furnace slag to stabilize low-level radioactive wastes, and also in the
manufacture of a ceramic-matrix composite material used in interior building applications.45
Iron Blast Furnace Air Pollution Control (ARC) Dust/Sludge
As discussed above, EPA sampling data indicate that some APC dust/sludge from iron blast furnaces
may exhibit the hazardous waste characteristic of EP toxicity at some facilities. Accordingly, the Agency has
conducted an intensive literature review of potential waste management alternatives and potential areas of
utilization, as described in Chapter 2. The major finding of this effort is that very little has been reported in
the published literature addressing these topics, suggesting that aside from recycling, there are few established
alternatives for the management of this material.
EPA has been able to establish that in 1988, iron producers reported that approximately 447,000
metric tons (36.3 percent) of the iron blast furnace APC dust/sludge was recycled to the beneficiation processes
via the sinter plant and blast furnace, 750,000 metric tons (60.9 percent) was disposed of, and 34,000 metric
tons (2.8 percent) was sold or sent off-site for further metal recovery.46 It is believed that at least some of
the APC dust/sludge which was sold or sent off-site, was probably used by zinc producers as a source of zinc.
Steel Furnace Slag
As discussed above, EPA does not expect that steel furnace slag would exhibit any of the four
characteristics of hazardous waste (corrosivity, reactivity, ignitability, or EP toxicity). Consequently, the issue
of how steel producers might modify their operations, waste management practices, or be stimulated to develop
alternative uses for steel furnace slag in response to prospective hazardous waste regulation is not applicable.
Any such operational changes that are currently contemplated by facility operators will therefore not be
affected by EPA's actions, and hence, are beyond the scope of this Report to Congress. Nonetheless, in the
following paragraphs, the Agency provides a brief summary of current and potential areas of steel furnace slag
utilization.
In 1988, 24 of the 26 steel mills in the U.S. generated over 13.2 million metric tons of steel slag.47
The primary management practices for steel furnace slag are recycling it to the blast furnace and processing
it for use as an aggregate. In 1988, U.S. steel mills recycled approximately 1.8 million metric tons of steel
slag.48 A nationwide survey of slag processors conducted by the Bureau of Mines indicated that over 5.1
million metric tons of steel furnace slag was sold or used in the U.S. in 1988 at an average price of $3.16 per
ton, ranging from an average of $144 when sold for railroad ballast to $4.55 when sold for asphaltic concrete
aggregate.49 The distribution of steel furnace slag among its various applications in 1988 is shown in Exhibit
44 Ibid., p. 2.
45 Personal communication, Judith F. Owens.
46 Company responses to the "National Survey of Solid Wastes from Mineral Processing Facilities," U.S. EPA, 1989.
47 Production statistics for two facilities are confidential and not included in this total.
* Judith F. Owens, "Slag-Iron and Steel," Minerals Yearbook-1988, U.S. Department of the Interior, Bureau of Mines, 1988, p. 2.
49 Ibid., p. 13.
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Chapter 8: Ferrous Metals Production 8-39
8-12. The remaining 6.3 million metric tons of steel furnace slag was presumably stockpiled at either the
generating facilities or at the slag processing facilities.
Eleven years of Canadian testing and evaluation of 18 bituminous test sections of a major urban
freeway showed that the most suitable mixtures for highways with high speed and heavy traffic are those
containing steel furnace slag or traprock for course and fine aggregates. Findings such as this one may lead,
in the future, to an expanding market for .utilization of steel furnace slag as asphaltic concrete aggregate.50
Steel Furnace Air Pollution Control (APC) Dust/Sludge
As discussed above, EPA sampling data indicate that APC dust/sludge from steel furnaces may exhibit
the hazardous characteristic of EP toxicity at some facilities. Accordingly, the Agency has conducted an
intensive literature review of potential waste management alternatives and potential areas of utilization, as
described in Chapter 2. The major finding of this effort is that very little has been reported in the published
literature addressing these topics, suggesting that aside from recycling, there are few established alternatives
for the management of this material.
EPA has been able to establish that in 1988, steel producers reported that approximately 57,700
metric tons (4 percent) of the APC dust/sludge was recycled to the beneficiation processes via the sinter plant
and blast furnace, 646,000 metric tons (44.2 percent) was disposed of, and 757,500 metric tons (51.8 percent)
was sold or sent off-site for further metal recovery.51 It is believed that the APC dust/sludge that was sold
or sent off-site was probably used by zinc producers as a source of zinc It may also be that not much of the
dust/sludge is recycled because of the presence of zinc and lead, both of which can cause problems in steel
production.
Exhibit 8-12
Primary Uses of Steel Furnace Slag52
Road base
Fill
Asphaltic concrete aggregate
Railroad ballast ice control, soil conditioning
46%
25%
11%
18%
8.6 Cost and Economic Impacts
Section 8002(p) of RCRA directs EPA to examine the costs of alternative practices for the
management of the special wastes considered in this report EPA has responded to this requirement by
evaluating the operational changes that would be implied by compliance with three different regulatory
scenarios, as described in Chapter 2. In reviewing and evaluating the Agency's estimates of the cost and
economic impacts associated with these changes, it is important to remember what the regulatory scenarios
imply, and what assumptions have been made in conducting the analysis.
The focus of the Subtitle C compliance scenario is on the costs of constructing and operating
hazardous waste land disposal units. Other important aspects of the Subtitle C system (e.g., corrective action,
prospective land disposal restrictions) have not been explicitly factored into the cost analysis. Therefore,
differences between the costs estimated for Subtitle C compliance and those under other scenarios (particularly
50 K.K. Tarn, R. Ratiborski, and DF. Lynch, Ministry of Transportation of Ontario, Canada, "11 Years Performance of 18 Bituminous
Test Sections on a Major Urban Freeway," prepared for presentation at the 1989 Transportation Researcn Board Annual Conference,
January 22-26, 1989, Washington, D.C
51 Company responses to the "National Survey of Solid Wastes from Mineral Processing Facilities,* U.S. EPA, 1989.
52 Ibid.
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8-40 Chapter 8: Ferrous Metals Production
Subtitle C-Minus) are less than they might be under an alternative set of conditions (e.g., if most affected
facilities were not already subject to Subtitle C, or if land disposal restrictions had been promulgated for
"newly identified" hazardous wastes). The Subtitle C-Minus scenario represents, as discussed above in
Chapter 2, the minimum requirements that would apply to any of the special wastes that are ultimately
regulated as hazardous wastes; this scenario does not reflect any actual determinations or preliminary
judgments concerning the specific requirements that would apply to any such wastes. Further, the
Subtitle D-Plus scenario represents one of many possible approaches to a Subtitle D program for special
mineral processing wastes, and has been included in this report only for illustrative purposes. The cost
estimates provided below for the three scenarios considered in this report must be interpreted accordingly.
In accordance with the spirit of RCRA §8002(p), EPA has focused its analysis on impacts on the firms
and facilities generating the special wastes, rather than on net impacts to society in the aggregate. Therefore,
the cost analysis has been conducted on an after-tax basis, using a discount rate based on a previously
developed estimate of the weighted average cost of capital to U.S. industrial firms (9.49 percent), as discussed
in Chapter 2. Waste generation rate estimates (which are directly proportional to costs) for the period of
analysis (the present through 1995) have been developed in consultation with the U.S Bureau of Mines.
In this section, EPA first outlines the way in which it has identified and evaluated the waste
management practices that would be employed by ferrous metal producers under different regulatory scenarios,
developed the cost implications of requiring changes in existing waste management practices, and predicted
the ultimate impacts of increased waste management costs associated with changes in the regulatory
environment faced by iron and steel facility operators.
8.6.1 Regulatory Scenarios and Required Management Practices
Because the available data indicated that iron blast furnace slag and steel furnace slag pose low risks
and do not exhibit any of the characteristics of hazardous waste, the issue of how waste management costs
might change if Subtitle C regulatory requirements were applied and what impacts such costs might impose
upon affected facilities is moot, and is not considered further in this report
In contrast, based upon the information presented above, EPA concluded that both iron and steel
APC dust/sludge could be subjected to regulation under Subtitle C absent the Mining Waste Exclusion. Waste
composition data collected by EPA and submitted by facility operators indicate that these materials may exhibit
characteristics of hazardous waste at some facilities, and the analysis of potential risk presented above
demonstrates that the physical form and chemical characteristics of these materials, the management practices
that are employed, and environmental settings in which waste management occurs could, in combination,
impose risk to human health and the environment Accordingly, the Agency has estimated the costs associated
with such regulation, as well as with two somewhat less stringent regulatory scenarios, referred to here as
"Subtitle C-Minus" and "Subtitle D" as previously introduced in Chapter 2, and as described in specific detail
below.
In conducting its cost analysis, EPA has adopted the approach that only those iron and steel facilities
that actually were sampled and whose waste(s) exhibited hazardous characteristics would be analyzed for
regulatory compliance. The Agency assumed that APC dust/sludge at facilities that were not sampled would
not exhibit the characteristic of EP tenacity-, this assumption is based on the fact that wastes from the majority
of the facilities sampled (and the great majority of the total number of samples) did not exhibit EP toxicity,
and no damage cases involving these wastes were found (See Section 833.). The Agency's cost and impact
analysis is therefore limited to five facilities: three facilities with potentially toxic APC residue from iron blast
furnace operations and two facilities with potentially toxic APC residue from steelmaking operations. APC
dust/sludge from these operations exhibited EP toxicity for selenium and/or lead.
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Chapter 8: Ferrous Metals Production 8-41
Subtitle C
Under Subtitle C standards, generators of "hazardous waste that is managed on-site must meet the
rigorous standards codified at 40 CFR Part 264 for hazardous waste treatment, storage, and disposal facilities.
Because the APC dusts and sludges are solid, non-combustible materials, and because under full Subtitle C
regulation, hazardous wastes cannot be permanently disposed of in waste piles, EPA has assumed that the
ultimate disposition of APC dust/ sludge would be in Subtitle C landfills that meet the minimum technology
standards specified at 40 CFR 264. EPA has assumed that the affected facilities would continue to internally
recycle the same quantity of dust/sludge as they do currently. The Agency has, however, assumed that the
affected facilities would not continue to dispose their wastes off-site if the cost is higher than operating an on-
site disposal landfill. The Agency has assumed that, in addition to the disposal units, the affected facilities
would also construct a temporary storage waste pile (with capacity of one week's waste generation) that would
enable the operators to send the dust/sludge to either on-site or recycling operations efficiently. This
assumption reflects current practice, which often includes management in waste piles.
Subtitle C-Minus
A primary difference between full Subtitle C and Subtitle C-Minus is the facility-specific application
of requirements based on potential risk from the hazardous special waste. Under the C-Minus scenario, as
well as the Subtitle D-Plus scenario described below, the degree of potential risk of contaminating ground-
water resources was used as a decision criterion in determining what level of protection (e.g., liner and closure
cap requirements) will be necessary to protect human health and the environment. One of the five facilities
of concern, US Steel/Fairless Hills, was determined to have a high potential to contaminate ground-water
resources; the other four were determined to have a moderate groundwater contamination potential. The
Fairless Hills facility, however, recycles its APC residue to the sinter/blast furnace operation and, therefore,
operates no on-site disposal units; this mode of operation would continue under C-Minus. A second of the
five facilities of concern, Sharon Steel's Earrell facility, currently disposes off-site; EPA!s cost comparison
analysis indicates that, under the C-Minus scenario, the facility would be likely to build an on-site disposal
landfill. The remaining three facilities, all of moderate risk, dispose on-site in landfills or impoundments, none
of which have liners that conform to the standards of this regulatory scenario. Therefore, each is assumed to
build new disposal landfills containing a three foot clay liner and a protective fill layer. Each must also
incorporate run-on/run-off controls and perform groundwater monitoring. In addition, the disposal units must
undergo formal closure, including a cap of topsoil and grass over a composite liner. Post-closure care must
be performed (e.g., leachate collection and treatment, cap and run-on/run-off control maintenance, and
continued groundwater monitoring) for a 30 year period.
Subtitle D-Plus
As under both Subtitle C scenarios, facility operators would, under the Subtitle D-Plus scenario, be
required to ensure that hazardous contaminants do not escape into the environment Like the Subtitle C-
Minus scenario, facility-specific requirements are applied to allow the level of protection to increase as the
potential risk to ground water increases. The four facilities which dispose on-site (Le., the Fairless Hills
facility will continue to recycle) are assumed to build new disposal landfills with three foot clay liners and a
protective fill layer. Each must incorporate run-on/run-off controls and perform groundwater monitoring.
In addition, the disposal units must undergo formal closure, including a cap of topsoil and grass over a
composite liner. Post-closure care must be performed (e.g., leachate collection and treatment, cap and run-
on/run-off control maintenance, and continued groundwater monitoring) for a period of 30 years.
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8-42 Chapter 8: Ferrous Metals Production
8.6.2 Cost Impact Assessment Results
Iron Blast Furnace APC Dust/Sludge
Regulatory compliance cost estimates for iron blast furnace APC dust/sludge are displayed in
Exhibit 8-13. Of the 26 facilities operating iron blast furnaces in the ferrous metals production sector, only
three are assumed to generate hazardous APC dust/sludge and, therefore, incur costs under the Subtitle C
scenario: U.S. Steel at Fairless Hills, Pennsylvania; Bethlehem Steel at Sparrows Point, Maryland; and LTV
Steel at East Cleveland, Ohio. Under the Subtitle C regulatory scenario, the annualized regulatory compliance
costs would, respectively, be $68,000, $10.6 million, and $3.5 million greater than baseline waste management
costs (76,16, and 7 times larger than baseline costs, respectively). With the exception of the facility in Fairless
Hills, the bulk of the compliance costs would be devoted to new capital expenditures. Specifically, the increase
in annualized new capital expenditures for each facility would be $33,700 at Fairless Hills, $8.3 million at
Sparrows Point, and $2.6 million at East Cleveland; increases in capital expenditures account for approximately
77 percent of the total annualized compliance costs for the sector. The majority of the prospective cost impact
is attributable to the design and construction of the large Subtitle C landfills that would be required to manage
this waste. The Fairless Hills facility has such low disposal costs because it utilizes (recycles) all of its air
pollution control (APC) dust, so that its compliance activities would consist only of building an APC dust
storage area (concrete pad) rather than a far more costly Subtitle C disposal landfill.
Under the facility specific risk-related requirements of the Subtitle C-Minus scenario, costs of
regulatory compliance are, for the sector, about half of those under the full Subtitle C scenario. The
annualized regulatory compliance costs for the Sparrows Point and East Cleveland facilities would be $4.6 and
$1.6 million greater, respectively, than the baseline waste management costs (7 and 3 times larger than
baseline). The cost savings of the Subtitle C-Minus scenario compliance over full Subtitle C costs result
primarily from needing fewer liners and a less elaborate leachate collection system for the disposal landfill;
capital costs are nearly 60 percent less under this scenario. Annualized compliance capital, however, continues
to drive total costs, with capital costs making up approximately 68 percent of the total. The Subtitle C-Minus
compliance costs for the Fairless facility would be nearly identical to its Subtitle C costs, since the technical
requirements for a temporary storage area are the same under both scenarios.
Costs under Subtitle D-plus are expected to be virtually identical to those under Subtitle C-minus
(different permit costs at the Fairless Hills facility are the only cost difference in the sector), as management
practices are the same.
Steel Furnace APC Dust/Sludge
Regulatory compliance cost estimates for steel furnace APC dust/sludge are displayed in Exhibit 8-14.
Of the 26 facilities operating steel furnaces in the ferrous metals sector, only two are assumed to generate
hazardous waste and, therefore, incur costs under the Subtitle C scenario: U.S. Steel at Lorain, Ohio, and
Sharon Steel at Farrell, Pennsylvania. Under the Subtitle C regulatory scenario, the annualized regulatory
compliance costs would be $3.3 million and $23 million greater than the baseline waste management costs
(9 and 3 times the baseline cost, respectively). The bulk of the annual compliance costs would be devoted to
new capital expenditures; about 75 percent of the total cost is annualized capital costs, approximately $4.1
million for the two facilities combined.
Under the facility specific risk-based requirements of the Subtitle C-Minus scenario, costs of
regulatory compliance are, for the sector, about 40 percent less than full Subtitle C costs. The annualized
regulatory compliance costs for the Lorain and Farrell facilities would be $1.6 and 0.94 million greater than
the baseline waste management costs, respectively (5 and 2 times larger than baseline). The cost advantage
over the full Subtitle C regulations results primarily from needing fewer liners and a less elaborate leachate
collection system for the disposal landfill.
-------
Exhibit 8-13
Compliance Cost Analysis Results for Management of
APC Dust/Sludge from Iron Blast Furnaces***
Faculty
LTV Steel - East Cleveland. OH
Bethlehem Steel - Sparrows Point, MD
U.S. Steel - Fairies* Hills. PA
Total:
Average:
Management Cost
Annual Total
(9000)
609
692
1
1.302
434
(ncramental Co*ta of Regulatory Compliance
Subtitle C
Annual
Total
($000)
3.489
10.591
68
14.148
4.716
Total
Capital
($000)
17.245
55,852
226
73,323
24,441
Annual
Capital
($000)
2.573
8,334
34
10,941
3,647
Subtitle C-Mlnua
Annual
Total
($000)
1,625
4,626
68
6,318
2,106
Total
Capital
($000)
6,748
22.013
226
28,987
9.662
Annual
Capital
($000)
1,007
3.285
34
4,325
1,442
Subtitle D-Plue
Annual
Total
($000)
1,625
4,626
60
6,310
2.103
Total
Capital
($000)
6,748
22.013
226
28,987
9.662
Annual
Capital
($000)
1,007
3.285
34
4,325
1,442
O
I
p?
•n
•^
3
I
O
3
Costs have been estimated only for facilities for which sampling data Indicate that the waste would exhibit a RCRA hazardous waste characteristic.
(a) Values reported In this table are those computed by EPA's cost estimating model, and are Included for Illustrative purposes. The data, assumptions, and computational
methods underlying these values are such that EPA believes that the compliance cost estimates reported here are precise to two significant figures.
00
*»
CO
-------
Exhibit 8-14
Compliance Cost Analysis Results for Management of
ARC Dust/Sludge from Steel (BOF & OHF) Furnaces***
Facility
Sharon Steel - East Cleveland, OH
U.S. Steel - Loraln. OH
Total:
Average:
Baseline Waste
MttlMQtflMflt CO0t
Annual Total
($000)
963
413
1.376
608
Incremental Costs of Regulatory Compliance
Subtitle C
Annual
Total
($000)
2.342
3,341
5,683
2,841
Total
Capital
($000)
12,993
14,717
27,710
13,655
Annual
Capital
($000)
1,939
2,196
4,135
2,067
Subtitle C-Mlnus
Annual
Total
($000)
936
1.680
2,616
1,308
Total
Capital
($000)
5.100
5.365
10.465
5,232
Annual
Capital
($000)
761
801
1,562
781
Subtitle O-Plus
Annual
Total
($000)
936
1.680
2,616
1.308
Total
Capital
($000)
5,100
5.365
10,465
5,232
Annual
Capital
($000)
761
601
1,562
781
00
it
o
I
00
o
i
5*
T)
5
a
o
Costs have been estimated only for facilities for which sampling data Indicate that the waste would exhibit a RCRA hazardous waste characteristic.
(a) Values reported In this table are those computed by EPA'a cost estimating model, and are Included for Illustrative purposes. The data, assumptions, and computational
methods underlying these values are such that EPA believes that the compliance cost estimates reported here are precise to two significant figures.
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Chapter 8: Ferrous Metals Production 8-45
Costs under Subtitle D-Plus re expected to be virtually identical to those under Subtitle C-Minus, as
management practices are the same and no facilities are in low risk areas, the one condition that allows for
differential landfill design and operating standards for the C-Minus and D-Plus scenarios.
8.6.3 Financial and Economic Impact Assessment
In order to evaluate the ability of the affected facilities to bear these estimated regulatory compliance
costs, EPA conducted an impact assessment which consisted of three steps. First, the Agency compared the
estimated compliance costs to the financial strength of each facility, to assess the relative magnitude of the
financial burden that would be imposed in the absence of changes in supply, demand, or price. EPA also
conducted a qualitative evaluation of the salient market factors which affect the competitive position of the
iron and steel producers, in order to determine whether compliance costs could be passed on to labor,
suppliers of raw materials, or consumers. Finally, the Agency combined the results of the first two steps to
predict the net compliance-related economic impacts which would be experienced by the facilities being
evaluated. The methods and assumptions used in this analysis are described in Chapter 2 and in a Appendices
E-3 and E-4 to this report.
Financial Ratio Analysis
Iron Blast Furnace APC Dust/Sludge
Based on ratio analysis, EPA expects regulation under Subtitle C to have no significant impacts on
the Fairless Hills facility, because its recycling operations circumvent the need for protective disposal
operations. The impacts on the East Cleveland and Sparrows Point facilities, while not highly significant, are
potentially significant; the Agency, therefore, has considered other factors such as market strength and ability
to pass through costs. The financial ratios, as seen in Exhibit 8-15, are comparisons of annualized compliance
costs to value of shipments and to total value added, and annualized compliance capital to annual sustaining
capital investments; generally these ratios for the affected facilities fall within the one to five percent range.
The magnitude of financial impacts under Subtitle C-Minus and, identically, D-Plus regulation would
be substantially less, though similar in distribution to those under full Subtitle C For example, compliance
cost as a percent of value added at the Sparrows point facility (the operation with the greatest impacts), falls
from 4.2 percent under Subtitle C to 2.4 percent under the Subtitle C-Minus and D-Plus scenarios.
Steel Furnace APC Dust/Sludge
EPA believes that regulation under any regulatory scenario would have only marginal impacts on
either facility generating steel furnace APC dust/sludge, as seen in Exhibit 8-16. Annual compliance costs as
a percentage of either value of shipments or value added are less than one percent, indicating an absence of
potentially significant impacts. Annualized compliance costs as a percentage of annual sustaining capital
investments, typically a high ratio in affected sectors, is only 2-3 percent, even under full Subtitle C controls.
For C-Minus and D-Plus scenarios this ratio is around one percent.
Market Factor Analysis
General Competitive Position
There have been extensive structural changes in the U.S. ferrous metals mining and processing indus-
try since the recession of the early 1980s. Domestic producers have made a number of changes in the 1980's
to make the overall iron and steel industry competitive on a worldwide basis. These included several steps:
1. Closure of high-cost mining operations and rationalization of iron ore production to a point
where generally lower cost capacity is maintained;
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8-46 Chapter 8: Ferrous Metals Production
Exhibit 8-15
Significance of Regulatory Compliance Costs for Management of
ARC Dust/Sludge from Iron Blast Furnaces(a)
Facility
Subtitle C
LTV Steel • East Cleveland, OH
Bethlehem Steel • Sparrows Point, MD
U.S. Steel • Fairless Hills, PA
Subtitle C-Mlnus
LTV Steel - East Cleveland, OH
Bethlehem Steel - Sparrows Point, MD
U.S. Steel - Fairless Hills, PA
Subtitle D-Plus
LTV Steel - East Cleveland, OH
Bethlehem Steel - Sparrows Point, MD
U.S. Steel - Fairless Hills, PA
CC/VOS
1.0%
1.6%
0.0%
0.5%
0.9%
0.0%
0.5%
0.9%
0.0%
CC/VA
2.6%
4.2%
0.1%
1.2%
2.4%
0.1%
1.2%
2.4%
0.1%
IR/K
2.6%
4.4%
0.0%
1.0%
2.3%
0.0%
1.0%
2.3%
0.0%
CC/VOS = Compliance Costs as Percent of Sales
CC/VA = Compliance Costs as Percent of Value Added
IR/K « Annualized Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported in this table are based upon EPA's compliance cost estimates. The Agency believes that these
values are precise to two significant figures.
Costs and impacts have been estimated for only those facilities for which sampling data indicate that the waste exhibits a
RCRA hazardous waste characteristic.
Exhibit 8-16
Significance of Regulatory Compliance Costs for Management of
ARC Dust/Sludge from Steel (BOF & OHF) Furnaces (a)
Facility
CC/VOS
CC/VA
IR/K
Subtitle C
Sharon Steel - Farrell, PA
U.S. Steel - Lorain, OH
0.4%
0.3%
0.7%
0.6%
2.9%
1.9%
Subtitle C-Minu*
Sharon Steel • Farrell, PA
U.S. Steel - Lorain, OH
0.1%
02%
0.3%
0.3%
1.1%
0.7%
Subtitle D-Plus
Sharon Steel - Farrell, PA
U.S. Steel - Lorain, OH
0.1%
02%
03%
0.3%
1.1%
0.7%
CC/VOS -= Compliance Costs as Percent of Sales
CC/VA - Compliance Costs as Percent of Value Added
IR/K - Annualized Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported in this table are based upon EPA's compliance coat estimates. The Agency believes that these
values are precise to two significant figures.
Costs and impacts have been estimated for only those facilities for which sampling data indicate that the waste exhibits a
RCRA hazardous waste characteristic.
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Chapter 8: Ferrous Metals Production 8-47
2. Substantial capital investment at remaining facilities to lower costs per iron unit to a point at
which domestically produced ore is competitive with ore delivered from oversees; and
3. Investments in iron and steel production process improvements at several mills throughout the
U.S.
These changes in the U.S. steel industry structure have allowed the U.S. producers to move from the
upper end to the middle end of the supply curve on a worldwide basis.
Potential lor Compliance Cost Pass-Through
Labor Markets. Imposing substantially lower wages to counteract compliance costs is not a likely
scenario in the ferrous metals industry. There have already been significant wage and benefit concessions and
movement in the opposite direction with regard to wages is likely over the next few years.
Raw Material Supply Markets. As many of the U.S. mine supplies have become more cost-
competitive, the possibilities of importing lower cost iron ore are declining. Also, the steel companies are
partially integrated into ore production and are unlikely to achieve cost savings by ore price rollbacks or mine
closures. The mines do provide a depletion allowance which can partially offset any imported ore price
savings.
Higher Prices. The possibility of passing along higher prices in the steel industry is rather limited.
The ferrous metals market is a world market and, therefore, U.S. prices must be in line with world prices.
There are many producers of foreign steel with equal or lower costs than those of the U.S.; substantial price
increases could therefore lead to increased imports. More importantly, EPAs data and analysis suggests that
only five of the 28 ferrous metals facilities that produce iron and steel would experience increases in waste
management costs in the absence of the Mining Waste Exclusion. It is extremely unlikely that these five
facilities could successfully pass through compliance costs to domestic consumers given the structure of
domestic and global iron and steel markets.
Evaluation of Cost/Economic Impacts
Only two of 28 facilities that generate iron/steel APC dust/sludge would face potentially significant
economic impacts under any regulatory scenario. For the two affected facilities, however, the impacts would
probably be marginally significant if operators continue to manage the material as a waste (i.e., not recycling
to the sinter/smelter operation). The remaining 26 facilities in the primary ferrous metals processing sector
will probably not suffer significant impacts if any of the four special wastes (i.e., including slag) generated
within the ferrous metals sector were to be removed from the Mining Atoste Exclusion. EPA emphasizes,
however, that these results are based upon limited waste characterization data; if additional facilities that were
not sampled generate EP toxic waste(s), then the costs and impacts predicted here would be underestimates
of the true magnitude of regulatory impacts.
Due to the international nature of the market for ferrous metals, U.S. producers would be unlikely
to be able to raise prices enough to pass through compliance costs. The Sparrows Point facility might be able
to use feedstock cost advantages (related to its coastal location, allowing for lower feedstock transportation
costs through use of ocean transport) to recover compliance costs, though recent losses across the industry
as a whole have left most facilities with very narrow profit margins. The East Cleveland facility, with its
owner/operator (LTV Steel) already in financial difficulties (i.e., having filed for bankruptcy), would be hard
pressed to absorb additional regulatory compliance costs and raise new capital for compliance-related
investments. The Agency points out, however, that recycling of the waste at these facilities, if technically
feasible (at least ten generators of iron blast furnace APC residue recycle all or some of the waste to
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8-48 Chapter 8: Ferrous Metals Production
sinter/smelter operations), would result in neither facility incurring any significant impacts under any regulatory
scenario.
As a final note, the Agency emphasizes that some cost and economic impacts would be likely to occur
even if the wastes are retained within the Mining Waste Exclusion, because adequately protective standards
under an eventual Subtitle D program would probably require the construction of new disposal units at most
plants, as reflected by the Subtitle D-Plus scenario presented here.
8.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) potential and documented danger
to human health and the environment; (2) the need for and desirability of additional regulation; and (3) the
costs and impacts of potential Subtitle C regulation.
Iron Blast Furnace and Steel Furnace Slag
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of iron blast furnace and steel furnace slags is relatively low compared to other
mineral processing wastes studied in this report. These wastes do not exhibit any of the four characteristics
of hazardous waste. Review of the available data on blast furnace and steel furnace slag solid samples and
leachate constituent concentrations indicates that only seven constituents are present at concentrations greater
than 10 times the conservative screening criteria used in this analysis. In blast furnace slag, concentrations
of manganese, iron, lead, arsenic, and silver exceed screening criteria by more than a factor of 10.
Concentrations of manganese, iron, chromium, thallium, and arsenic in steel furnace slag exceed one or more
of the conservative screening criteria in one or more samples by more than a factor of 10. In addition,
aqueous extracts of both blast furnace and steel furnace slag are highly alkaline (pH up to 11.7). These
exceedances indicate the potential for the slags to pose risks under very conservative, hypothetical exposure
conditions. The actual exposure conditions at the active facilities, however, are not as conducive to human
health or environmental damage as those upon which the screening criteria are based, in large part because
the slags consist of large solid fragments that are not easily dispersed, and from which contaminants are not
readily released. These findings lead EPA to conclude that the intrinsic hazard of these slags is relatively low.
Based on a review of the site-specific conditions at 11 facilities, the potential for blast furnace and
steel furnace slag to cause significant impacts appears low at most of the active facilities. The potential for
significant releases to ground water is often limited by a low net recharge and a large depth to ground water.
The potential for significant surface water impacts is limited by the large particle size of the slag (which
precludes erosion) as well as the large distances to water bodies, large surface water flow rates, and great
downstream distances to potential receptors at many sites. The large particle size of the slag also limits the
potential for significant airborne releases.
This overall low-risk conclusion is supported by the general lack of documented cases of damage
attributable to the slags. Even though the slags have been generated and managed at many sites for several
decades, EPA identified only one damage case and that case is associated with an inactive facility that was
operated under rather unusual conditions. EPA believes that the management controls and environmental
conditions at a few of the active facilities are, in theory, also favorable for contaminant releases to ground and
surface water, but no releases attributable to the slags are known to have occurred at these sites in the past
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Chapter 8: Ferrous Metals Production 8-49
Ukelihood That Existing Risks/Impacts Will Continue in the Absence of Subtitle C Regulation
The conditions that currently limit the potential for significant threats to human health and the
environment are expected to continue to limit risks in the future in the absence of more stringent federal
regulation. The character of the waste is not expected to change and no new blast furnace or primary steel
furnace facilities are expected to be constructed in the near future. The slags are widely used at off-site
locations, which conceivably could be conducive to releases and risks at present and in the future. However,
based on the paucity of documented cases of damage from blast furnace and steel furnace slag, EPA believes
that the conclusion of low hazard can be extrapolated to off-site locations of slag disposal or use and to other
locations where slag might be used in the future.
Both iron blast furnace slag and steel furnace slag are processed, sold, and used extensively for a
variety of purposes, such as road base material, 511, asphaltic concrete aggregate, and railroad ballast.
Consequently, both types of slag, particularly iron slag, are often handled as commodities rather than wastes.
Ongoing research efforts suggest that new processing technologies will allow the use of slag for additional
purposes, which would further reduce the quantity of ferrous metal slag requiring disposal.
State regulation of blast furnace and steel furnace slag is similar in the five states that were reviewed
for purposes of this report. For the most pan, the states exempt slag from regulation when it is reprocessed
or stored temporarily (i.e., not disposed permanently). Iron and steel slag management, therefore, generally
is not subject to solid waste (or other land-based) regulation in any of these states, though in some cases waste
slag is disposed of in a permitted landfill. Slags that are disposed of permanently on-site or sent off-site to
an approved landfill are generally subjected only to minimal requirements (e.g., covers, run-on/run-off con-
trols). As with solid waste regulation, the application of water regulations (i.e., state and/or federal NPDES
requirements) to slag wastes generally is not extensive, though it varies considerably from state to state and
facility to facility. Moreover, with few exceptions, the states are imposing only minimal, if any, fugitive dust
controls on slag waste piles. The management of these slags under solid waste regulations, however, is likely
to change dramatically in the near future. Four of the five study states are in the process of proposing or
implementing new waste regulations which would address these materials, while the fifth state recently enacted
new ground-water protection legislation. Presumably these new regulations will result in more comprehensive
and stringent management and disposal practices, though the extent to which this is b'kely to happen is unclear.
Costs and Impacts of Subtitle C Regulation
Because of the low risk potential of iron and steel slags, the general absence of documented damages
associated with these materials, and the fact that iron and steel slags do not exhibit any characteristics of
hazardous waste, EPA has not estimated the costs and associated impacts of regulating iron and steel slags
under RCRA Subtitle C.
Iron and Steel Air Pollution Control Dust/Sludge
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of blast furnace and steel furnace APC dust/sludge is generally moderate to high
in comparison with the other mineral processing wastes studied in this report Based on EP leach test results
of blast furnace APC dust/sludge, 4 out of 70 samples (from 3 out of 16 facilities tested) contain lead
concentrations in excess of the EP toxicity regulatory levels. Selenium was also measured in EP leachate of
blast furnace and steel furnace APC dust/sludge in concentrations that exceed the regulatory level in 1 out of
64 samples of blast furnace APC dust/sludge and 1 out of 7 samples of steel furnace APC dust/sludge.
Moreover, blast furnace APC dust/sludge contains 12 constituents at concentrations that exceed one or more
of the conservative screening criteria used in this analysis by more than a factor of 10. In steel furnace APC
dust/sludge, the concentrations of eight constituents exceed one or more of the conservative screening criteria
by more than a factor of 10. In addition, aqueous extracts of both blast furnace and steel furnace APC
-------
8-50 Chapter 8: Ferrous Metals Production
dust/sludge are highly alkaline (pH up to 12.5). While releases and exposures are generally not expected to
be as large as the hypothetical conditions .upon which the screening criteria are based, the dusts/sludges consist
of small particles that are prone to environmental release and transport when not properly controlled.
Based on an examination of the site-specific conditions at 17 facilities, the current management of
blast furnace and steel furnace APC dust/sludge poses a low threat at some facilities but a moderate to high
threat at others. In general, the potential for the dust/sludge to cause significant ground-water impacts is
limited at most sites that manage the waste in a dry form (in stockpiles, landfills, waste piles, etc.) because of
the low net recharge, depth to ground water, and/or distance to potential receptors. When managed in
impoundments, however, there is a considerably greater potential for the dust/sludge contaminants to migrate
into ground water. EPA believes that the potential for the dust/sludge contaminants to migrate into surface
water is high at 13 of the facilities because of the wastes' small particle size, a lack of engineered controls to
limit releases, and a close proximity to surface water bodies. However, contaminants entering rivers near all
but four of these facilities are likely to be readily assimilated by the rivers' large flow. Considering the
susceptibility of the dust/sludge to wind erosion, the exposed surface area of waste management units, the lack
of dust suppression controls, atmospheric conditions, and population distributions, there is also a relatively
high potential for airborne releases and exposures at seven facilities. Despite these theoretical conclusions
about potential hazards, EPA did not identify a single case of environmental degradation that can be attributed
to the dust/sludge. Therefore, considering the site-specific conditions together with the lack of damage cases,
EPA concludes that the dusts/sludges pose an overall moderate risk.
Likelihood That Existing Risks/Impacts Will Continue In the Absence of Subtitle C Regulation
As discussed above, APC dust/sludge waste management practices and environmental conditions at
a number of iron and steel production facilities may allow contaminant releases and moderate risks.
Continuation of current management practices in the absence of more stringent federal regulation will
continue to pose risks to human health and the environment from APC dusts/sludges into the future. For
example, only 1 of the 5 facilities evaluated in this analysis that manages these wastes in impoundments utilizes
engineered controls such as liners or leachate collection systems to restrict releases to ground water. Similarly,
although the dust is susceptible to wind erosion, only 8 of the IS facilities that manage dust in landfills or
waste piles practice any dust suppression measures. Therefore, environmental releases can occur and,
considering the intrinsic hazard of the dust/sludge, significant exposures could occur if affected ground water
is used as a source of drinking water.
In addition to the potential impacts at the facilities evaluated in this analysis, threats to human health
and the environment may occur at other locations now and in the future as a result of off-site disposal of APC
dust/sludge. For example, five facilities reported that they sent all their blast furnace APC dust/sludge off-site
for disposal in 1988, and although risks from these off-site locations have not been evaluated in detail because
of a lack of site-specific information, it is likely that dust/sludge management at some of these locations may
present threats to human health or the environment. The production of steel has increased steadily in recent
years, though future growth in demand is expected to be moderate. EPA believes that much of this future
demand will be met by mini-mills (which utilize secondary materials and do not generate special wastes) rather
than by the addition of new blast furnace or steel furnace facilities.
The management and disposal of APC dust and sludge are, to a large extent, not being addressed
under solid waste regulations by the five states reviewed for this report, though these wastes are landfilled by
facilities in at least two states and are therefore subject to all pertinent regulations governing landfills. APC
dust and/or sludge that is disposed of permanently on-site or sent off-site to an approved landfill generally is
subjected only to nunimal requirements (e.g., covers, run-on/run-off controls). As with solid waste regulations,
the application of water regulations (Le,, state and/or federal NPDES requirements) to APC dusts and sludges
generally is not extensive, though it varies considerably from state to state and facility to facility. Moreover,
with few exceptions, the states are imposing only minimal, if any, fugitive dust controls on APC dust/sludge
waste piles. The management of these wastes under solid waste regulations, however, is likely to change dra-
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Chapter 8: Ferrous Metals Production 8-51
matically in the near future. Four of the five states studied for this report are in the process of proposing or
implementing new waste regulations that would address these materials, while the fifth state recently enacted
new ground-water protection legislation. Presumably these new regulations will result in more comprehensive
and stringent management and disposal practices, though the extent to which this is likely to happen is unclear.
Costs and Impacts of Subtitle C Regulation
EPA has evaluated the costs and associated impacts of regulating iron blast furnace APC dust/sludge
and steel furnace APC dust/sludge as hazardous wastes under RCRA Subtitle C. EPA's waste characterization
data indicate that these materials may exhibit the hazardous waste characteristic of EP toxicity at three and
two facilities, respectively. Because neither of these wastes exhibited hazardous characteristics at the majority
of facilities that were sampled and because there were only a small total number of EP toxicity test
exceedances, EPA assumed that these wastes would not exhibit characteristics (and hence, be subject to
regulation in the absence of the Mining Waste Exclusion) at facilities that were not sampled. For iron blast
furnace APC dust/sludge, costs of regulatory compliance under the full Subtitle C scenario range from $68,000
per year at the Fairless Hills facility (which recycles its dust) to more than S10 million annually at Bethlehem's
Sparrows Point plant; these costs might impose potentially significant economic impacts on the operators of
two of the three affected plants. For steel furnace APC dust/sludge, Subtitle C compliance would result in
incremental costs of about $2.3 million and $3.3 million at the two affected facilities. Application of the more
flexible Subtitle C-Minus regulatory scenario would result in compliance costs that are approximately 55
percent lower. Costs under the Subtitle C-Minus and Subtitle D-Plus scenarios are similar (or identical) at
all three affected iron facilities and both affected steel plants, because adequately protective waste management
unit design and operating standards are essentially the same under both scenarios, given the nature of the
waste and the environmental settings in which it is currently managed.
Costs of full Subtitle C compliance would comprise a potentially significant fraction of the value of
shipments of and value added by one affected iron producer (Sparrows Point). Compliance costs at the other
four ferrous metals facilities are moderate or low, based upon the Agency's screening criteria. Under the less
stringent Subtitle C-Minus scenario, compliance costs are not likely to impose significant impacts on any of
the affected facilities. Given the modest nature of the prospective cost impacts of modified Subtitle C and
Subtitle D regulation, and the relatively healthy position of domestic ferrous metals producers, EPA does not
believe that potential regulatory compliance costs under RCRA Subtitle C would impose significant economic
impacts upon affected facilities. These costs would not be shared among all domestic producers (affected facil-
ities account for approximately 13 percent of domestic iron capacity, and seven percent of carbon steel capa-
city), and therefore, affected facilities may be put at a competitive disadvantage with respect to other domestic
producers. Nevertheless, the Agency does not believe that the long-term profitability and continued operation
of these plants would be threatened by a decision to regulate either iron or steel APC dust/sludge under
Subtitle C.
In addition, it is worthy of note that these impacts would be likely to occur even in the absence of
a decision to remove the air pollution control wastes from the Mining Waste Exclusion, because adequately
protective waste management standards under a Subtitle D program would require the construction of new
waste management units at most plants, implying significant new capital expenditures.
Finally, EPA believes that no significant disincentives for recycling or utilization of the APC dusts
and sludges would be created if a change in the regulatory status of these wastes were to occur. Recycling is
currently the predominant alternative to disposal that is applied to these materials. It is possible that tighter
regulatory controls on the management of APC dust/sludge might serve to promote even greater recycling than
has occurred in the recent past (approximately 36 percent of iron APC dust/sludge was recycled in 1988).
Utilization of the dusts and sludges has not been widely reported, though limited quantities of iron blast
furnace APC dust/sludge were sold for metal recovery (zinc) in 1988. It is not likely that removing iron blast
furnace or steel furnace APC dusts/sludges from the Mining Waste Exclusion and thereby subjecting them to
regulation as hazardous wastes would significantly limit or prevent this practice.
-------
Chapter 9
Hydrofluoric Acid Production
For purposes of this report, the hydrofluoric acid production industry consists of three facilities that,
as of September 1989, were active1 and reported generating two special mineral processing wastes:
fluorogypsum and process wastewater from hydrofluoric acid production.2 The data included in this chapter
are discussed in additional detail in a technical background document in the supporting public docket for this
report.
9.1 Industry Overview
Hydrofluoric acid is used primarily for the production of fluorocarbon chemicals, including
fluoropolymers and chlorofluorocarbons.3 Hydrofluoric acid is also used in the aluminum processing industry
for the manufacture of synthetic cryolite and aluminum fluoride for reduction cells. In addition, it is used in
the manufacture of uranium tetrafluoride, an intermediate in the processing of nuclear fuel and explosives.
Furthermore, hydrofluoric acid is used in petroleum alkylation, oil and gas well treatment, stainless steel
pickling, and cleaning and etching in some specialty glass and electronics applications. It is also utilized in
the manufacture of fluorine chemicals used in herbicides, fluoride salts, plastics, water fluoridation, rare metals
processing, and other applications.
The three currently active facilities and their production capacities are shown in Exhibit 9-1. The
Geismar facility initiated operations in 1967 and was modernized in 1983; the Calvert City facility (formerly
owned by Pennwalt Corp.) began operations in 1949 and was modernized in 1959.4 A full SWMPF Survey
response was not submitted by the LaPorte facility; therefore, no dates of initial operation or modernization
are available for that facility. The aggregate 1988 production of hydrofluoric acid for the Geismar and Calvert
City facilities was 116,795 metric tons; using the aggregate production capacity for the two facilities as reported
in Exhibit 9-1, the average annual capacity utilization rate was 97.3 percent.
More than 70 percent of the reported fluorspar consumption.in the U.S. in 1989 was for hydrofluoric
acid production.5 The reported consumption of acid-grade fluorspar has risen throughout the last half of the
decade from 383,000 metric tons in 1985 to 449,000 metric tons estimated in 1989. This rise in acid-grade
fluorspar consumption indicates that the demand for hydrofluoric acid has risen throughout the late 1980s.6
The U.S. imported approximately 119,000 metric tons of hydrofluoric acid in 1988, nearly all of it (98 percent)
from Canada and Mexico.7
1 A hydrofluoric acid facility was operated by Essex Chemical Corporation in Paulsboro, NJ until being "mothballed" in 1987. This
facility, representing about five percent of the total 1987 aggregate production capacity (1989 Directory of Chemical Producers, SRI
International, p. 691) is not addressed in this report.
2 Several production facilities are operating which produce hydrofluoric acid as an intermediate product in the formulation of
commercial chemicals or compounds. The 1989 Directory of Chemical Producers (SRI International, p. 691) reports, for example, that
"Aluminum Company of America produces hydrofluoric acid as a nonisolatable product;" Bureau of Mines has confirmed that ALCOA
produces hydrofluoric acid at Point Comfort, TX. These facilities did not nominate as special wastes any hydrofluoric acid production
waste streams from their operations, are not considered to be pan of the primary hydrofluoric acid industry, and therefore, are not
addressed in this report.
3 Bureau of Mines, 1987. Minerals Yearbook. 1987 Ed., p. 373.
4 Allied Signal, Inc., 1989, and Pennwalt Corp., 1989. Company responses to the "National Survey of Solid Wastes from Mineral
Processing Facilities," US. EPA, 1989.
5 David E. Morse, U.S. Bureau of Mines, "Fluorspar," Minerals Yearbook. 1988 Ed., p. 3.
6 M. Michael Miller, U.S. Bureau of Mines, "Fluorspar," Mineral Commodity Summaries. 1990 Ed., p. 60.
7 Morse, og. cit., p. 7.
-------
9-2 Chapter 9: Hydrofluoric Acid Production
Exhibit 9-1
Domestic Hydrofluoric Acid Producers
Owner
Allied Signal
E.I. duPont
Attochemical, N.A.
Location
Geismar, LA
LaPorte, TX
Calvert City, KY
Capacity (MT)(a)
95,000
68,000
25,000
(a) SRI International, 1987. Directory of Chemical Producers-United States. 1987 Ed., p. 964.
Generally, U.S. producers of hydrofluoric acid are very competitive in the world market. U.S. firms
are able to import low-cost Mexican acid-grade fluorspar for domestic hydrofluoric acid production. Since all
of the acid-grade fluorspar used in the production of hydrofluoric acid is currently imported, the establishment
of additional hydrofluoric acid production facilities is limited more by market access requirements than a lack
of raw materials. The demand for hydrofluoric acid may increase in the future due to the 1987 Montreal
Protocol on Substances that Deplete the Ozone Layer. The U.S. and 22 other countries are party to the
protocol, which calls for significant reductions in chlorofluorocarbon (CFC) consumption over the next decade.
This could affect the demand for hydrofluoric acid because its primary use is in the production of fluorocarbon
chemicals, including CFCs, and substitutes for CFCs are likely to require increased amounts of flourine.
Alternatively, CFC substitutes could themselves require use of hydrofluoric acid, so that a CFC phase-out
could actually increase demand for hydrofluoric acid.
Hydrofluoric acid is produced from acid-grade fluorspar (CaF^) which is reacted with sulfuric acid in
a heated retort kiln to produce hydrogen fluoride gas, as shown in Exhibit 9-18 The residue remaining after
retorting is calcium sulfate anhydrite, commonly known as fluorogypsum, which is a special waste. This solid
is slurried in process water as it exits the kiln and is transported either to the waste management units9 or,
at the duPont plant, to a production operation for further processing for sale as a byproduct.10 The crude
product gas is purified by scrubbing; process wastewater reportedly is generated by this process as well.11
The process wastewater, the second special waste generated by this sector, is storedAreated in on-site surface
impoundments and then reused in the process operations or discharged. The hydrogen fluoride gas is
condensed and distilled to form anhydrous hydrogen fluoride, a colorless fuming liquid. This liquid may be
sold as is or absorbed in water to form hydrofluoric acid.
9.2 Waste Characteristics, Generation, and Current Management Practices12
The three hydrofluoric acid facilities generate both solid and aqueous special mineral processing
wastes, which are fluorogypsum and process wastewater, respectively.
8 Bureau of Mines, 1985. Mineral Facts and Problems. 1985 Ed, p. 283.
9 Allied Signal, Inc., 1989. Public comments from Allied Signal, Inc. addressing the 1989 Proposed Reinterpretation of tbe Mining
Waste Exclusion (Docket No. MW2P00020); November 8,1989, p. 1.
10 At the duPont facility, lime is added when the fluorogypsum is quenched in order to enhance the chemical characteristics of the
material for construction applications.
11 Pennwalt, 1989. Public comments from Pennwalt Corporation addressing the 1989 Proposed Reinterpretation of the Mining Waste
Exclusion (Docket No. MW2P00013); November 8,1989, p. 1.
12 All responses, unless otherwise noted, are from the response of Allied Signal, Inc. and Pennwalt Corp. to EPA's "National Survey
of Solid Wastes from Mineral Processing Facilities," conducted in 1989.
-------
Chapter 9: Hydrofluoric Acid Production 9-3
Exhibit 9-2
Hydrofluoric Acid Production
AcW Orad« .
Fluorspar
Heated
Retort
Hydrogen .
Fluoride p
Condensation
* Distillation
Hydrofluoric ^
Acid *
MANAGEMENT
Calcium Sulfote
vAnhydrite (Fluorogypsum)
Process Woste»oter
/ Processing A
Storage.
FKxroqyp»um / Oiipbsol \ Process Wostewoter
1Impoundn
Stocks
Recycle or Discharge
Legend
I I Production Operation
Special Watte
o
Watte Management Unit
Fluorogypsum
Fluorogypsum is a solid material consisting primarily of fine particles of calcium sulfate, usually less
than 0.02 mm in diameter, that is slurried for transport from the kilns to waste management units.
Using available data on the composition of fluorogypsum, EPA evaluated whether the waste exhibits
any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and extraction procedure
(EP) toxicity. Based on analyses of 4 samples from 2 facilities (Geismar and Calvert City) and professional
judgment, the Agency does not believe the fluorogypsum exhibits any of these characteristics. All eight of the
inorganic constituents with EP toxicity regulatory levels were measured in concentrations (using the EP leach
test) that were at least two orders of magnitude below the regulatory levels.
EPA estimates that the total quantity of fluorogypsum generated in 1988 at the three active facilities
was 894,000 metric tons, ranging from 241,000 to 329,000 metric tons. The average annual generation was
297,000 metric tons with an average waste to product ratio of 4.83.
Because the two materials are largely co-managed at all three facilities, the management of
fluorogypsum is discussed in the next section, along with process wastewater.
Process Wastewater
Process wastewater is an aqueous liquid, the chemical constituents of which include fluoride, calcium,
and sulfate, with smaller amounts of iron and silicon, as well as many trace metals.
Using available data on the composition of hydrofluoric acid process wastewater, EPA evaluated
whether the wastewater exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity,
ignitability, and extraction procedure (EP) toxicity. Based on available information and professional judgment,
-------
9-4 Chapter 9: Hydrofludrlc Acid Production
the Agency does not believe that the wastewater is reactive, ignitable, or EP toxic. All eight of the inorganic
constituents with EP toxicity regulatory levels were measured in concentrations (using the EP leach test) that
were no more than 0.6 times the regulatory levels. Some wastewater samples, however, exhibit the
characteristic of corrosivity. Analyses of the pH of hydrofluoric acid process wastewater at the Geismar and
Calvert City facilities indicated that the wastewater was corrosive in all of the nine samples analyzed,
sometimes with pH values as extreme as 1.00 (for comparison, pH levels below 2.0 are operationally defined
as corrosive wastes).
EPA estimates a total of 13.6 million metric tons of process water are generated annually, ranging
from 2.9 to 5.7 million metric tons. The average generation per facility is 4.5 million metric tons and the
average ratio of process wastewater to hydrofluoric acid product is 73.63.
Each of the three facilities manages the two special wastes somewhat differently. At the Calvert City
facility, the fluorogypsum is slurried in process wastewater and routed with other process wastewaters to a
treatment facility where the pH of the combined streams is adjusted with lime. The entire treated slurry is
then routed to an on-site surface impoundment, which received over 3.8 million cubic meters (one billion
gallons) of water in 1988. The fluorogypsum settles to the bottom and accumulates there until the pond is
filled to capacity. After the solids settle, the liquids are routed to a 16 hectare (40 acre) clarifying pond, the
pH is adjusted again, and the water is either recycled or discharged to a nearby river. Once filled, the settling
ponds are closed with the fluorogypsum in place and a new pond is opened. There are three settling ponds
at this facility, two of which are closed. Each of the closed ponds is between 20 and 30 hectares in area, ranges
from 4.5 to 9 meters deep, and holds an estimated 3,200,000 metric tons of dried, solid fluorogypsum. The
active pond covers approximately 16 hectares, is 9 meters deep, and held (as of mid-1989) approximately 1.3
million metric tons of fluorogypsum submerged beneath liquid.
At the Geismar facility, fluorogypsum is slurried with recycled process water and pumped to
fluorogypsum stacks; the facility's stacks are devoted entirely to storage and disposal of fluorogypsum in a
manner "facilitating reclamation" (through aging of fluorogypsum in the stacks). The fluorogypsum solids
settle to the bottom of holding ponds on top of the stack, and are dredged and dumped immediately adjacent
to the ponds to initially form and subsequently build up benns or dikes. The fluorogypsum is dredged and
dumped in this fashion on a continuous basis as the holding ponds are filled, slowly increasing the height of
the surrounding benns.
Given this management practice, the fluorogypsum exists in three different physical forms at the
Geismar facility: (1) as sediment submerged beneath liquid in a holding pond; (2) as wet sediment/sludge
freshly dredged and placed on the benns; and (3) as dried solids on the berms. When wet, fluorogypsum has
a texture similar to wet cement (a very moist, pasty mixture of solid particles ranging from sand size to
cobbles) and, when dry, the fluorogypsum is a very hard, solid mass, not unlike dried cement, rock, or
wallboard.
The combined area of the fluorogypsum stack covers almost 17 hectares (43 acres), and the berms
range from 11 meters to 20 meters high. As of late 1988, the total quantity of fluorogypsum accumulated in
the stack was roughly 2.7 million metric tons. Transport water and precipitation run-off that drains from the
stacks are held in an impoundment for reuse in the operation; additional process wastewater may be routed
directly to this impoundment, may be used in on-site operations, or may be directly recycled to the
hydrofluoric acid operation.
As solids settle out in these ponds, overflow effluent is gravity fed from one pond to the next until
the clarified process wastewater eventually reaches a final surface impoundment termed a "clearwell pond."
This impoundment covers almost 4.1 hectares (10 acres), is roughly 2.5 meters deep, and holds roughly 5.7
million cubic meters (1.5 billion gallons) of wastewater and 45,400 metric tons of sludge. From the clearwell
pond, the process wastewater is recycled on-site for a variety of uses.
Fluorogypsum at the LaPorte facility is lime-neutralized at the point of generation and is transported
in slurry form (in process wastewater) to a gypsum stack, after which it undergoes further processing and
subsequent sale for a number of construction-related uses.
-------
Chapter 9: Hydrofluoric Acid Production 9-5
9.3 Potential and Documented Danger to Human Health and the Environment
In this section, EPA discusses two of the study factors required by Section 8002(p) of RCRA for the
special wastes generated in the hydrofluoric acid sector: (1) potential risk to human health and the
environment associated with the management of fluorogypsum and hydrofluoric acid process wastewater; and
(2) documented cases in which danger to human health and/or the environment has been proven. Overall
conclusions about the hazards associated with each of these two wastes are based on the Agency's evaluation
of these two factors.
9.3.1 Risks Associated With Fluorogypsum and
Hydrofluoric Acid Process Wastewater
Any potential danger to human health and the environment posed by fluorogypsum and hydrofluoric
acid process wastewater depends on the presence of hazardous constituents in the wastes and the potential
for exposure to these constituents.
Fluorogypsum Constituents of Potential Concern
EPA identified chemical constituents in fluorogypsum that may present a hazard by collecting data
on the composition of this waste and evaluating the intrinsic hazard of the chemical constituents.
Data on Fluorogypsum
EPA's characterization of fluorogypsum and its leachate is based on data from two sources: (1) a 1989
sampling and analysis effort by EPA's Office of Solid Waste (OSW); and (2) industry responses to a RCRA
§3007 request in 1989. These data provide information on the concentrations of 20 metals, 4 ions (nitrate,
fluoride, chloride, and sulfate), 1 radionuclide (radium-226), and 2 organic compounds (benzene and methyl
ethyl ketone) in fluorogypsum solids and leachate. The leachate data were generated using EP, SPLP, and
TCLP leach tests. Two of the three facilities that generate fluorogypsum are represented by these data: Allied-
Signal in Geismar, LA, and Attochem in Calvert City, KY.
There are no particularly noteworthy trends in the data. With a very few exceptions, the
concentrations of individual constituents in fluorogypsum solids are consistent (within an order of magnitude)
across the two data sources and two facilities; the EP, SPLP, and TCLP leach test results are also usually
within an order of magnitude of each other across the two facilities. However, several constituents were
detected in higher concentrations in SPLP leach tests than EP leach tests. Neither facility is reported to have
consistently higher (or lower) contaminant concentrations than the other.
Process for Identifying Constituents of Concern
As discussed in Section 2.2.2, the Agency evaluated the waste composition data summarized above
to determine if fluorogypsum contains any chemical constituents that could pose an intrinsic hazard. The
Agency performed this evaluation by first comparing the concentration of chemical constituents to screening
criteria and then by evaluating the environmental persistence and mobility of constituents that are present at
levels above the criteria. These screening criteria were developed using assumed scenarios that are likely to
overestimate the extent to which constituents in fluorogypsum are released to the environment and migrate
to possible exposure points. As a result, this process eliminates from further consideration those constituents
that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic organisms, and water resources (see Exhibit 2-3). Given the conservative (i.e., protective)
nature of these screening criteria, contaminant concentrations in excess of the criteria should not, in isolation,
be interpreted as proof of hazard. Instead, exceedances of the criteria indicate the need to evaluate the
potential hazards of the waste in greater detail.
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9-6 Chapter 9: Hydrofluoric Acid Production
Identified Constituents of Potential Concern
Based on a comparison of the concentrations of 24 constituents to the screening criteria summarized
above, there do not appear to be any constituents in fluorogypsum solids in concentrations that exceed the
screening criteria. That is, even under a very conservative set of release and exposure conditions, the chemical
concentrations in fluorogypsum solids are not expected to pose a significant risk.
Of the 25 constituents analyzed in fluorogypsum leachate, eight are present in concentrations that
exceed the screening criteria: arsenic, sulfate, lead, chromium, mercury, iron, manganese, and aluminum (see
Exhibit 9-3). All of these constituents are metals or other inorganics that do not degrade in the environment.
Arsenic and sulfate exceeded the screening criteria most frequently (in 100 percent of the samples); however,
only lead exceeded the screening criteria by more than a factor of six. Despite these exceedances of the
screening criteria, none of the samples contained any constituents in excess of the EP toxicity regulatory levels.
These exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• Arsenic, lead, and chromium concentrations in the fluorogypsum leachate may pose a
health risk if the leachate is released to ground water, diluted by a factor of 10 or less
during migration to a downgradient drinking water well, and ingested without prior
treatment over a long period of time. The diluted concentration of arsenic could result
in a cancer risk exceeding 1 x 10"5.
• If the fluorogypsum leachate is released to ground water and diluted by less than ten-
fold, the resulting concentrations of arsenic, sulfate, lead, chromium, iron, and
manganese could exceed the drinking water maximum contaminant level (MCL) for
these constituents.
• Concentrations of lead, chromium, mercury, and aluminum in the fluorogypsum leachate
may present a threat to aquatic organisms if the leachate migrates (with less than 100-
fold dilution) to surface waters.
Although the two sources of data used to characterize the composition of fluorogypsum do not
provide data on the radionuclide content of fluorogypsum leachate, such data are available from field
monitoring results at the Allied-Signal site and at a site in Louisiana where fluorogypsum was used to
construct a test highway embankment (see the damage case descriptions for more detail). Seven samples of
run-off/seepage/leachate from this site contained elevated gross alpha radiation levels, ranging from 79 pCi/1
to 226 pCi/1. Two additional samples of "ambient" surface water collected adjacent to the test embankment
also contained elevated gross alpha concentrations of 24 to 103 pCi/1. The levels in all eight samples exceed
the primary drinking water MCL of 15 pCi/1 (by factors that range from 2 to 15). Similarly, two run-off
samples contained radium-226 concentrations of 8 and 22 pCi/1, both of which exceed the MCL of 5 pCi/1.13
These exceedances of the screening criteria, by themselves, do not demonstrate that fluorogypsum
poses a significant risk, but rather indicate that the waste may present a hazard under a set of very conservative
hypothetical release, transport, and exposure conditions. To determine the potential for fluorogypsum to cause
significant impacts, EPA analyzed the actual conditions that exist at the facilities that generate and manage
the waste (see the following section on release, transport, and exposure potential).
Process Wastewater Constituents of Potential Concern
Using the same process outlined above for fluorogyr .m, EPA identified chemical constituents in
hydrofluoric acid process wastewater that conceivably may prc^nt a hazard.
13 EPA has only one sample result for the radionuclide concentration in fluorogypsum solids. In one fluorogypsum sample from the
Allied-Signal facility, radium-226 was measured in a concentration of 2.5 pCi/g, which is below the screening criterion of 5 pCi/g.
-------
Chapter 9: Hydrofluoric Acid Production 9-7
Exhibit 9-3
Potential Constituents of Concern in Fluorogypsum Leachate^
Potential
Constituents
of Concern
Arsenic^
Sulfate(c)
Lead(c)
Chromium'0'
Mercuryw
Iron
Manganese
Aluminum'6'
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
7/7
5/5
3/7
6/7
1/7
2/2
2/2
2/2
Screening Criteria ^
Human Heatth*
Resource Damage
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
Resource Damage
Resource Damage
Aquatic Ecological
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
7/7
2/7
5/5
2/7
3/7
2/7
2/7
2/7
2/7
1/7
1/2
1/2
1/2
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
2/2
1/2
1 /1
1/2
1/2
1 /2
1 12
1 12
1 12
1/2
1 12
1/2
1 12
(b)
(e)
Constituents listed in this table are present in at least one sample from at least one facility at a concentration that
exceeds a relevant screening criterion. The conservative screening criteria used in this analysis are listed in
Exhibit 2-3. Constituents that were not detected in a given sample were assumed not to be present in the sample.
Unless otherwise noted, the constituent concentrations used for this analysis are based on EP leach test results.
Human hearth screening criteria are based on cancer risk or noncancer health effects. 'Human health' screening
criteria noted with an '"' are based on a 1x10's lifetime cancer risk; others are based on noncancer health effects.
Data for this constituent are from SPLP leach test results.
Data on Process Wastewater
Two data sources were used to characterize the composition of hydrofluoric acid process wastewater:
data gathered by OSW in a 1989 field sampling effort, and data submitted by industry in response to a §3007
request in 1989. These sources provide data on the concentrations of 20 metals, sulfate, and pH in process
wastewater and wastewater leachate from the Geismar and Calvert City facilities.
Based on a comparison of the sample concentrations, the data from the two facilities are generally
consistent, though the concentrations of barium, chromium, and lead in the wastewater from the Allied-Signal
plant are one order of magnitude higher than corresponding concentrations at the Calvert City facility.
Identified Constituents of Potential Concern
Of the 22 constituents analyzed in hydrofluoric acid process wastewater, 14 are present in
concentrations that exceed the screening criteria. These 14 constituents, the type of screening criteria they
exceed, and the frequency with which they exceed the criteria are summarized in Exhibit 9-4. All of these
constituents are inorganics that do not degrade in the environment.
-------
9-8 Chapter 9: Hydrofluoric Acid Production
Of the 14 constituents that exceed the screening criteria, only six were present in concentrations that
exceed the criteria by more than a factor of 10: antimony, copper, iron, lead, manganese, and thallium.
Measured concentrations of iron in the wastewater exceed the screening criteria by the widest margin (by as
much as a factor of 160). None of these constituents were ever detected at levels that exceed the EP toxicity
regulatory levels, however, and based on professional judgment, EPA does not believe that the wastewater
exhibits the hazardous waste characteristics of ignitability and reactivity. However, some wastewater samples
exhibit the characteristic of corrosivity. The pH values of the wastewater may be either very low (e.g., 1.0 to
1.9 at the Geismar and Calvert City plants prior to treatment) or very high (e.g., 12 to 14 at the LaPorte plant
after treatment).
These exceedances of the risk screening criteria indicate the potential for the following types of
impacts:
• If hydrofluoric acid process wastewater is released to ground water and diluted by a
factor of 10 or less during migration to a downgradient drinking water well, con-
centrations of lead, chromium, antimony, and thallium could pose a health risk if the
water is ingested without treatment on a long-term basis.
• Concentrations of iron, copper, aluminum, nickel, zinc, lead, and chromium in the
process wastewater could present a threat to aquatic organisms if the wastewater
migrates (with 100-fold dilution or less) to surface waters.
• If the process wastewater is released to ground water and diluted by a factor of 10 or
less, the resulting concentrations of several constituents could render the water
unsuitable for certain uses (i.e., cause water resource damages). Specifically, the
resulting concentrations of iron, manganese, sulfate, lead, and chromium could exceed
the drinking water maximum contaminant levels for these constituents. The con-
centrations of molybdenum, aluminum, nickel, and vanadium could also exceed
irrigation guidelines, rendering the water less desirable for agricultural purposes.
• If the process wastewater is released to ground or surface water at the Geismar or
Calvert City facilities, the resulting pH levels may be less than the lower pH limit
established for use as drinking water (6.5). Conversely, if the process wastewater is
released at the LaPorte facility, the pH in receiving waters may be higher than the pH
limit for drinking water use (8.5). Both low and high pH may cause increased
corrosivity and an unpleasant taste.
As discussed above, these exceedances of the screening criteria, by themselves, do not demonstrate
that the process wastewater poses a significant risk, but rather indicate that the wastewater may present a
hazard under a very conservative hypothetical set of release, transport, and exposure conditions. To determine
the potential for the wastewater to cause significant impacts, EPA proceeded to the next step of the risk
assessment to analyze the actual conditions that exist at the facilities that generate and manage the waste.
Release, Transport, and Exposure Potential
This analysis evaluates the baseline hazards of fluorogypsum and hydrofluoric acid process wastewater
as they were generated and managed at the three hydrofluoric acid production plants in 1988. It does not
assess the hazards of off-site use or disposal of the wastes. Neither of the wastes are disposed of off-site, but
fluorogypsum may be used off-site as a lightweight aggregate, as discussed in Section 9.5. The hazards
associated with the off-site use of fluorogypsum are discussed in the context of a damage case in Section 9.3.2.
The following analysis also does not consider the risks associated with variations in waste management
practices or potentially exposed populations in the future because of a lack of sufficient data to predict future
conditions.
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Chapter 9: Hydrofluoric Acid Production 9-9
Exhibit 9-4
Potential Constituents of Concern in
Hydrofluoric Acid Process Wastewater (Total)(a)
Potential
Constituents
of Concern
Iron
Manganese
Thallium
Copper
Antimony
Molybdenum
Aluminum
Nickel
Zinc
SuHate
Vanadium
Lead
Chromium
PH
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
1 /I
1 /1
1/1
1 /I
t/1
1/1
t/1
1/1
i n
1/1
1/1
1 12
t/2
919
Screening Criteria
Resource Damage
Aquatic Ecological
Resource Damage
Human Health
Aquatic Ecological
Human Health
Resource Damage
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Aquatic Ecological
Resource Damage
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
1/1
1 /1
1 /1
1 /I
1 /1
1 n
1 /i
1/1
1/1
1/1
1 /i
1/1
1/1
1 n
1 12
1 12
1 12
i/a
1/2
1/2
9/9
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
1/1
1 M
1 /1
1 n
1 /i
1 /i
1 /i
1/1
1/1
1 /i
1 /i
1/1
1 /i
1 /i
1 12
1 12
1 12
1/2
1/2
1/2
2/2
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that
exceeds a relevant screening criterion. The conservative screening criteria used in this analysis are listed in
Exhibit 2-3. Constituents that were not detected in a given sample were assumed not to be present in the sample.
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9-10 Chapter 9: Hydrofluoric Acid Production
Ground-Water Release, Transport, and Exposure Potential
As discussed in the preceding section, EPA and industry test data show that several constituents in
fluorogypsum leachate and hydrofluoric acid process wastewater are present in concentrations above the
screening criteria. Considering the pH of the leachate and wastewater, several of the constituents are expected
to be mobile in ground water if they migrate from the waste management units, including arsenic, lead,
chromium, manganese, iron, thallium, copper, antimony, nickel, zinc, and sulfate.
The potential for these constituents to be released to ground water and cause subsequent impacts
varies according to site-specific conditions, as summarized below:
• The fluorogypsum stack and clearwell pond at the Geismar, LA facility are underlain
by in-situ clay and recompacted local clay. Both the stack and the pond are surrounded
by an unlined "interceptor ditch" that is designed to capture run-off and leachate; fluids
collected in this ditch are pumped back to the clearwell pond. Although the water table
is as shallow as 3 meters beneath the site, the uppermost useable aquifer is considerably
deeper, roughly 55 meters below the land surface.14 This deeper aquifer is used
primarily for livestock watering. The nearest downgradient well appears to be located
2.4 km (1.5 miles) away. The facility reports that it does not routinely monitor ground-
water quality at the site.
• The settling ponds at the facility in Calvert City, KY are underlain by in-situ clay. The
ponds are surrounded by slurry walls and ground-water monitoring wells to help control
leachate migration. An aquifer that is used as a rural domestic drinking water supply
is located roughly 5 meters below the land surface. Because the ponds at this site are
roughly 9 meters deep, it is likely that the base of the ponds extends beneath the water
table. The nearest downgradient drinking water well appears to be located 3.6 km (2.3
miles) from the facility.
• The fluorogypsum stack and process wastewater impoundments at the facility in
LaPorte, TX are surrounded by an unlined drainage ditch to help capture seepage and
run-off. Although ground water is relatively shallow (6 meters deep) and therefore
potentially susceptible to contamination, the site is located in an extremely in-
dustrialized area near the Houston shipping channel and the suitability of the surfitial
ground water for domestic use appears limited. The closest potential users of the
ground water are located more than 200 meters downgradient. The extent to which the
shallow ground water has been contaminated (if at all) is not known because no
monitoring has been conducted in recent years.
Although the fluorogypsum and process wastewater management units at each site are equipped with
some type of leachate control system, these controls do not appear to be completely sufficient to prevent
contamination of the shallow ground water at each site. This is substantiated by ground-water monitoring
around the ponds at the Carvert City facility, which has indicated levels of cadmium, fluoride, iron, manganese,
pH, and total dissolved solids that exceed the drinking water standards. Fluorogypsum and process wastewater
are possible contributors to this contamination. As discussed in the preceding sections, EPA sample analyses
found iron and manganese to be readily teachable from fluorogypsum, and found high concentrations of iron
and manganese and low pH levels in process wastewater. Contamination seeps around the clearwell pond at
the Geismar facility (see the damage cases) provide further indication of the potential for existing on-site
management practices to cause ground-water contamination.
Given its extremely high or low pH, migration of the process wastewater into ground water may
significantly damage the value of the ground water as a potential resource. A low pH may cause the need for
14 Company responses to the "National Survey of Solid Wastes from Mineral Processing Facilities" (EPA 1989) from the Arcadian
phosphoric acid plant, which is adjacent to the Allied Signal plant, indicate that useable ground water occurs at a depth of 24 meters at
this location.
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Chapter 9: Hydrofluoric Acid Production 9-11
heavier chlorination, whereas a high pH may cause increased halogen reactions. Both excessively high and low
pH values will cause increased corrosivity. Although high and low pH values may cause an unpleasant taste,
a wide range of pH values for drinking water can be tolerated from a human health standpoint.15
The toxic constituents present in any ground-water contamination are not expected to cause significant
human health impacts at present because:
• The shallow ground water beneath the Geismar facility is not useable, the useable
aquifer is considerably deeper and more protected, the deeper aquifer does not appear
to be used for human consumption, there are no downgradient wells that are close, and
the concentrations of most constituents of concern in the waste exceed conservative
screening criteria by less than a factor of 10 (and thus are likely to be well below levels
of concern at distant exposure points);
• Existing slurry walls should help contain any contamination at the Calvert City plant
and, even if contamination did escape, the closest well is far away and not likely to be
significantly affected by the generally low concentrations of toxic constituents; and
• The shallow ground water at the LaPorte facility is not likely to be used for drinking
within close distances.
EPA acknowledges, however, that human health risks could occur in the future if ground water near
the waste management units is ever used for drinking, or if the wastewater is managed in a more sensitive
environmental setting in the future.
Surface Water Release, Transport, and Exposure Potent/a/
The fluorogypsum stack and clearwell pond area at the plant in Geismar, LA is located roughly 600
meters from the Mississippi River and 1,200 meters from the Bayou Breaux (a relatively small stream).
Significant migration of contaminants into the Mississippi River appears unlikely because a levee on the bank
of the river should prevent overland erosion and because ground water in this area appears to migrate from
the river toward the facility. Even if contaminants did migrate into the Mississippi, the river's very large flow
provides a significant enough assimilative capacity to disperse the contaminants. However, as discussed in the
damage case section, the smaller Bayou Breaux could be contaminated in the event of a pipeline spill or a
large failure of the fluorogypsum stack berms. Routine releases to the bayou are expected to be largely
precluded by the interceptor ditch that surrounds the waste management units at this facility. The level of
fluids collected in this ditch is controlled by an automatic pump that turns on when the fluid level reaches a
certain height and pumps the liquid back to the clearwell pond.
The nearest surface water body at the plant in Calvert City, KY is the Tennessee River, located
roughly 1,040 meters away. It appears unlikely that any contamination originating from the ponds could
migrate to this river, either via ground-water seepage or direct overland run-off, because the ponds are
equipped with slurry walls and run-on/run-off controls. The plant discharges treated process wastewater to
the river in accordance with a NPDES permit and monitors the concentration of contaminants in the effluent
on a weekly basis. The plant also monitors the ambient water quality, and reports that it has not observed
an exceedance of drinking water or ecological protection criteria in the river. In the vicinity of the plant, the
Tennessee River is very large, with an annual average flow of 16 million cubic meters (4,211 million gallons)
per day. This river is used as a source of industrial process water at a point 520 meters downstream and as
a source of drinking water at a point 25 km (16 miles) downstream. Considering all of these factors, it is
unlikely that the routine management of fluorogypsum and process wastewater at this plant could cause
significant surface water impacts.
The LaPorte facility is located roughly 50 meters from the San Jacinta Bay. Releases to this water
body are possible, either through ground-water seepage or by direct overland runoff. Although the
15 EPA, 1984. National Secondary Drinking Water Regulations. EPA 570/9-76-000, June 1984, p. 30.
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9-12 Chapter 9: Hydrofluoric Acid Production
fluorogypsum and process wastewater impoundment at the site are surrounded by a drainage ditch that is
designed to control overland run-off, plant personnel-have indicated that the ditch has overflowed several times
because of severe storms. Because the San Jacinta Bay is saline, it is not used for drinking water. Therefore,
any contamination originating from the LaPorte facility is not likely to pose a direct drinking water threat, but
could conceivably cause an aquatic ecological threat.
Air Release, Transport, and Exposure Potential
Because the primary constituents of fluorogypsum and process wastewater from hydrofluoric acid
production are nonvolatile inorganics, contaminants can only be released to air in the form of dust panicles.
The release of dust, however, is precluded by the form of the wastes; fluorogypsum is either a hard solid mass
or is submerged beneath liquid, while the process wastewater is a liquid. The most likely airborne release
mechanism appears to be the potential for dust suspension caused by vehicular traffic on top of the
fluorogypsum stacks in Louisiana and Texas. Any such airborne releases should have a minimal impact
because, based on sampling data from EPA and industry, the fluorogypsum solids do not contain any
constituents in concentrations that may pose a risk through the inhalation pathway.
Proximity to Sensitive Environments
All three hydrofluoric acid plants are located in or near environments that are either vulnerable to
releases of contaminants or have high resource value that may warrant special consideration. In particular:
• The Calvert City plant is located in an endangered species habitat, according to the
operator's response to the SWMPF Survey.
• The Geismar and Calvert City plants are both located in 100-year floodplains; large
floods could create the potential for large, episodic releases.
• All three of the facilities are located within one mile upgradient of a wetland (defined
here to include swamps, marshes, bogs, and other similar areas). Wetlands are
commonly entitled to special protection because they provide habitats for many forms
of wildlife, purify natural water, provide flood and storm damage protection, and afford
a number of other benefits.
• The Calvert City plant is located in a fault zone. This creates the potential for
earthquake damages to the slurry walls that help to contain ground-water contamination
from the ponds at this site.
Risk Modeling
Based upon the evaluation of available data, the intrinsic hazard of the wastes and factors that
influence risk presented above, a review of the risk modeling results for other mineral processing wastes, and
a review and evaluation of information on documented damage cases (presented in the next section), EPA
concluded that process wastewater and fluorogypsum were not high priorities for quantitative risk modeling.
Accordingly, no risk modeling was performed.
9.3.2 Damage Cases
State and EPA regional files were reviewed in an effort to document the performance of process
wastewater and fluorogypsum waste management practices at the three active hydrofluoric acid facilities:
Attochem (Pennwalt) in Calvert City, Kentucky, duPont in LaPorte, Texas; and Allied Signal in Geismar,
Louisiana. The file reviews were combined with interviews with State and EPA regional regulatory staff.
Through these case studies, EPA found documented environmental damages associated with the co-
management of process wastewater and fluorogypsum at one facility, Allied-Signal in Geismar, and with the
off-site utilization of fluorogypsum from the Geismar facility.
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Chapter 9: Hydrofluoric Acid Production 9-13
Allied-Signal, Geismar, Louisiana
This facility is located south of Baton Rouge in an industrial/agricultural area; the nearest residence
is about 1.6 km (one mile) away. Its receiving waters are the Bayou Breaux and the Mississippi River.
Ground water in this area is used for livestock watering.
Releases from the Gypsum Stack/Clearwell
Fluorogypsum generated from the production of hydrofluoric acid is slurried with process water as
it is removed from the furnace; the resulting slurry is transferred through a conduit system to an impoundment
on the top of a fluorogypsum stack. Seepage and run-off from the fluorogypsum stack is collected in clay-lined
ditches and flows into an impoundment referred to as the clearwell. Some water from the clearwell is recycled
into various plant operations, while excess water is discharged as needed into the Mississippi River via a
NPDES permitted outfall after passing through a wastewater treatment plant.16'17
To avoid excessive levels of water in the clearwell during periods of high rainfall, which could lead
to catastrophic failure of the containing levee, Allied has on occasion bypassed the treatment facility and
discharged the clearwell water directly into the Mississippi River. This situation is allowed by EPA and
Louisiana Department of Environmental Quality (LADEQ) under proper emergency circumstances (i.e., prior
notice, reasonable cause). Emergency discharges occurred in January 1983;18 and from August 1983 through
October 1983.19 In April 1984, Allied notified EPA of its intention to again bypass the treatment facility
when discharging its clearwell water if its level rose another 30 cm, to a depth of 9 meters (30 feet).20
Allied has discharged or spilled untreated wastewater during other situations as well. In April 1978,
Allied noted a seepage area northwest of the clearwell; subsequent sampling revealed a low pH and the
presence of phosphate in the seepage.21 In July 1978, a gypsum line break reduced pH levels in a drainage
ditch feeding into Bayou Breaux.22 Allied discovered another leak in October 1980 in the northeast corner
of the clearwell. Consultants to Allied noted that contaminated water penetrating the clay surfacing was
"resulting in vegetation kills which cannot be tolerated."23 In August 1981, a gypsum slurry transport line
ruptured and a portion of the Bayou Breaux dropped in pH from around 7 to as low as Z.6.24
One of the primary difficulties in managing the gypsum stack and clearwell areas is preventing their
physical failure. Stack failures have occurred in the past. In May 1979, Allied's east gypsum stack failed,
16 Allied-Signal, Inc., 1989. Company response Co the "National Survey on Solid Wastes from Mineral Processing Facilities," U.S. EPA,
1989.
17 LA Stream Control Commission, 1977. Permit Application to Discharge Wastewater Revision form by William Chamberlain,
General Manager of Allied. July 1,1977.
18 EPA Region VI, 1983. Letter from Myron O. Knudson, Director Water Management Division, to Herman J. Baker, Allied Chemical
plant manager, Re: Administrative Order Docket No. VI-83-057, NPDES Permit No. LA0006181. January 1,1983.
19 Louis J. Capozzoli and Associates, Inc. Consulting Engineers, 1983. Letter from Louis J. Capozzoli and Associates, Inc. to Allied
Chemical, Re: Modification of Operations Gypsum Stack and Clearwell. August 8,1983.
20 Swidler, Berlin and Strelow, 1984. Letter from L. Miller to Jack Ferguson, EPA Region VI, Re: NPDES Permit No. LA0006181.
April 24,1984.
21 Allied Chemical, 1980. Letter to Kenneth Cooper, EPA Region VI, Re (additional information on area northwest of Allied's
phosphate clearwell). February 2,1980.
22 Allied Chemical, 1978. Letter from W.P. Chamberlain, General Manager to R-A. Lafleur, Executive Secretary, LA Stream Control
Commission, Re: (gypsum line break). July 31,1978.
23 Allied Chemical, 1980. Letter from WJ. Dessert, Manager Environmental to Dale Givens, LA Water Pollution Control Division,
Re: (Letter and supplemental information for October 24,1980 meeting between Allied Chemical and EPA Region VI). November 11,
1980.
24 Allied Chemical, 1981. Letter from W.P. Chamberlain, General Manager to Jack Ferguson, Chief Industrial Compliance Section
(6E-WC), EPA Region VI, Re: NPDES Permit No. La 0006181. October 20, 1981.
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9-14 Chapter 9: Hydrofluoric Acid Production
resulting in the overflow of low pH gypsum slurry water into a roadside ditch along Highway 30.An
estimated 95 percent of the spilled water was recovered. In October 1980, consultants to Allied Chemical
identified four interrelated clearwell and gypsum stack problems: (1) levee overtopping; (2) levee stability
(high risk of stack failure); (3) levee crest subsidence; and (4) levee toe leak.27 In August 1983, another slide
(failure) occurred on Allied's gypsum stack.
Re/eases Associated with the Use of Gypsum as Road Construct/on Material
Within the time period from 1986 to 1987, in an effort to find a profitable use for the large quantities
of gypsum waste accumulating at Allied Signal's facility, Louisiana Synthetic Aggregates, Inc. (LASYNAG)
began marketing the gypsum as a road base material.28 According to consulting engineers contracted by
LASYNAG, the gypsum was processed by milling (excavating and screening) the material from the
fluorogypsum stockpile located at the Allied-Signal hydrofluoric acid plant in Geismar, Louisiana. Once
milled, the fluorogypsum was marketed and shipped as "Florolite."29
In 1987, LASYNAG had the milled fluorogypsum analyzed by several laboratories for. different
parameters. One laboratory reported that with a resistivity of 500 ohms-cm and a pH of 5.2, the material is
considered very corrosive for most iron and steel products. The laboratory also stated that the high sulfate
content and the low pH would likely make the material corrosive to concrete as well.30
During 1987, after several rounds of requests and data submittals, Louisiana's Department of
Transportation and LADEQ's Office of Solid and Hazardous ^fcste authorized the use of Florolite on various
road shoulders, embankments, and base courses.31'32 At least some of these approved projects were
completed, including road work at a mobile home park.33
In July 1988, the City of New Orleans Department of Streets concluded that the material would be
acidic and corrosive for iron, steel, and concrete products, and deemed the use of Florolite as a road base
material in the City inadvisable.34
On June 7, 1989, LASYNAG began construction of a test embankment for the "U.S. Highway 90
relocation construction project" through a stretch of wetlands in southern Louisiana near Amelia. After three
25 Allied Chemical, 1979. Letter from W.P. Chamberlain to R-A. Lafleur, with attachments, Re None, (failure of east gypsum stack).
June 25,1979.
26 EPA Region VI, 1983. Letter from Myron O. Knudson, Director Water Management Division, to Herman J. Baker, Allied Chemical
plant manager, Re: Administrative Order Docket No. VI-83-057, NPDES Permit No. LA0006181. January 21,1983.
27 Allied Chemical, 1980. Letter from WJ. Dessert, Manager Environmental to Dale Givens, LA Water Pollution Control Division,
Re: (Letter and supplemental information for October 24,1980 meeting between Allied Chemical and EPA Region VI). November 11,
1980.
28 LASYNAG, located in Gretna, Louisiana, is owned by Coastal Contractors, Inc., of Baton Rouge.
29 G&E Engineering, Inc., 1989. Analyses of Florolite Aggregate Runoff and Surface Waters - U.S. Highway 90 Reallocation
Construction Site-Obtained in Response to LADEQ Compliance Order. September, 1989.
30 Analysis Laboratories, Inc., 1987. Letter to C Lundstrom, Eustis Engineering Co., Re Examination of Florolite Sample. March
27,1987.
31 Louisiana Department of Transportation. Projects Containing Florolite. Date unknown.
32 LADEQ, 1987. Letter from J. Koury, OSHW, to D.G. Azar, LASYNAG, Re Use of Allied Chemical Company Gypsum. June
8,1987.
33 LADEQ, 1987. Complaint form received by Jesse Chang from anonymous resident in Twin Lakes Mobile Home Park, Re: None.
(use of Allied Chemical's gypsum for road paving and GU). January IS, 1987.
* City of New Orleans Department of Streets, 1988. Letter from RJ. Kaufmann to J. Poolych, LASYNAG, Re: None (Use of
Florolite as road base material). July IS, 1988.
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Chapter 9: Hydrofluoric Acid Production 9-15
weeks, LADEQ responded to complaints of dying biota and found "extremely acidic pH and high conductivity
in water adjacent to the roadbed." Construction was ceased immediately.35
Exhibit 9-5 summarizes the analytical results for run-off/seepage/leachate samples collected near a
Florolite stockpile at the Amelia test site. These results show pH values ranging from 1.6 to 2.9, while sulfate
concentrations ranged from 6,030 to 11,500 mg/L, up to 46 times the National Secondary Drinking Water MCL
of 250 mg/L. Arsenic, cadmium, chromium, lead, and mercury levels also exceeded Primary MCLs in run-off/
seepage/leachate samples. In addition, gross alpha and radium levels were detected at levels above MCLs in
several samples.36
As shown in Exhibit 9-6, ambient surface water samples collected adjacent to the embankment
exhibited elevated levels of pH, sulfates, salinity, and specific conductivity, as well as arsenic, cadmium,
chromium, and lead. The elevated concentrations in comparison to the more remote ambient surface water
sampling locations were attributed by LASYNAG to leaching and/or run-off from the "Florolite"
embankment.37
In addition to sampling the Florolite stockpile at the Amelia site, Allied also sampled "fluorogypsum
run-off/leachate water" from the Allied-Signal fluorogypsum stockpile. From analysis of one sample, elevated
levels of arsenic, cadmium, chromium, lead, mercury, gross alpha radiation, and radium, were detected
(Exhibit 9-7).38
LASYNAG is now undertaking remedial measures to remove the environmental hazard posed by
Florolite at the Amelia test site.39
9.3.3 Findings Concerning the Hazards of Fluorogypsum and Process
Wastewater
Although both fluorogypsum and hydrofluoric acid process wastewater contain several constituents
in concentrations that could pose significant risk under worst-case exposure conditions, the process wastewater
is intrinsically much more hazardous. Based on an analysis of nine samples, the wastewater consistently
exhibits the hazardous waste characteristic of corrosivity (the pH may be as low as 1.0 at the Geismar and
Calvert City facilities, and as high as 14 at the LaPorte facility). The wastewater also contains six constituents
in concentrations that exceed the screening criteria by a factor of 10 or more, though none of the constituents
were detected in excess of the EP toricity regulatory levels. In contrast, no constituents were detected in the
fluorogypsum solids in concentrations that could pose a risk, and only one contaminant in the fluorogypsum
leachate (lead) exceeded the screening criteria by more than a factor of 10. Run-off/leachate samples collected
at the Allied-Signal stack as well as the test embankment site near Amelia, LA indicate that fluorogypsum
leachate may contain elevated levels of gross alpha radioactivity and radium-226, but the gross alpha and
radium concentrations that were measured rarely exceeded the MCL by more than a factor of 10.
Furthermore, based on available data and professional judgment, EPA does not believe that fluorogypsum
exhibits any of the characteristics of a hazardous waste.
Based on an analysis of existing exposure and environmental conditions at the three active
hydrofluoric acid production plants, there is a relatively high potential for shallow ground-water contamination
caused by the seepage of process wastewater and the migration of fluorogypsum leachate. This is substantiated
by documented ground-water contamination near the impoundment at the Calvert City facility and observed
35 G&E Engineering, Inc., 1989. Analyses of Florolite Aggregate Runoff and Surface Waters - U.S. Highway 90 Reallocation
Construction Site • Obtained in Response to LADEQ Compliance Order. September, 1989.
*Ibid.
37 Ibid.
38 Ibid.
39
Ibid.
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9-16 Chapter 9: Hydrofluoric Acid Production
Exhibit 9-5
Run-off/Seepage/Leachate from Florolite at Test Site Near Amelia, LA
Parameter
As
Cd
Cr
Pb
Hg
Gross Alpha
Total Radium
pH
MCL
(rng/g^
0.05
0.01
0.05
0.05
0.002
15pCi/L
5pCi/L
6.5 - 8.5 S.U.
No. Samples
Exceeding MCL'"
4
7
7
7
2
6
2
7
Range of
Exceedance (mg/L)(b>
0.2-1.1
0.07 - 0.56
0.67 - 9.5
0.3 - 1 .6
0.0043 - 0.0050
79 - 226 pCi/L
8-22pCi/L
1.4 -2.9 S.U.
(a) Out of 7 samples collected.
(b) Except as noted.
Exhibit 9-6
"Ambient" Surface Water (Area Affected by Florolite)
at Test Site Near Amelia, LA
Parameter
As
Cd
Cr
Pb
Gross Alpha
pH
MCL
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Chapter 9: Hydrofluoric Acid Production 9-17
Exhibit 9-7
Fluorogypsum Run-off/Leachate Water From The
Allied-Signal Fluorogypsum Stockpile
Parameter
As
Cd
Cr
Pb
Hg
Gross Alpha
pH
MCL (mfl/L)
0.05
0.01
0.05
0.05
0,002
15pCi/L
6.5 - 8.5 S.U.
Sample Concentration
(mg/L)('»
0.06
0.18
3.6
0.5
0.0062
140pCi/L
t.rs.u.
(a)
One sample collected (07/11/89).
contamination seeps around the process wastewater "clear/well" pond at the Geismar facility. This
contamination is not expected to cause significant health risks at present, either because the shallow ground
water is not likely to be used at close downgradient distances (as is the case at Geismar and LaPorte) or
because the waste management units are equipped with slurry walls and a monitoring well network to help
contain any contamination (as is the case at Calvert City). However, the very low or high pH of the process
wastewater could cause considerable ground-water resource damage (e.g., affected ground water may be
corrosive, have an objectionable taste, and require additional treatment prior to use).
The potential for significant releases to surface water during routine operations is limited at each site
by some type of management control, including perimeter ditches, retention ponds, and/or slurry walls. Even
if contaminants did migrate to nearby surface waters at the Calvert City and La Pone facilities, both of the
sites borders major water bodies (the Tennessee River and San Jacinta Bay) that should be able to readily
assimilate the low pollutant loadings that would be expected. The smaller Bayou Breaux near the Geismar
facility may receive contaminants in the event of spills and gypsum stack failures, but routine releases to the
bayou are expected to be minimal given the site's perimeter ditch system and the large distance (1,200 meters)
separating the bayou from the waste management units. Occasional overflows and emergency discharges to
surface waters have occurred during major storms, but these are generally isolated events that are controlled
under the NPDES program.
Considering the form of the wastes (nonvolatile liquids and moist/wet solids) and the absence of any
contaminants that could pose an inhalation threat, the potential for significant releases and exposures via the
air pathway appears very low.
Documented cases of damage identified by EPA provide two important findings. First, the damage
case at the Geismar facility demonstrates difficulties in preventing the physical failure of gypsum stacks. There
have been at least six separate incidents since 1979 in which the stack at this facility failed (i.e., slumped,
collapsed, and/or overflowed). Although relatively rare, these failures allow sporadic large releases of the
highly acidic process wastewater. Second, the documented case of environmental contamination caused by the
off-site use of fluorogypsum demonstrates that the distribution and use of this material warrants close control.
Specifically, when used off-site for applications that result in contact with the land (e.g., road construction),
pH adjustment is required to prevent adverse environmental impacts, and run-off controls are needed to
prevent the spread of potentially harmful concentrations of contaminants.
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9-18 Chapter 9: Hydrofluoric MCid Production
9.4 Existing Federal and State Waste Management Controls
9.4.1 Federal Regulation
Under the Clean Water Act, EPA has the responsibility for setting "effluent limitations," based on
the performance capability of treatment technologies. These "technology based limitations," which provide the
basis for the minimum requirements of NPDES permits, must be established for various classes of industrial
discharges, including a number of ore processing categories.
Permits for mineral processing facilities may require compliance with effluent guidelines based on best
practicable control technology currently available (BPT) or best available technology economically achievable
(BAT). BPT effluent limitations for existing sources applicable to discharges resulting from the production
of hydrofluoric acid include (40 CFR 415.82):
Pollutant
Total Suspended Solids
Total Fluorine
Total Nickel
Total Zinc
PH
Dally Maximum
11 Kg/kkg
6.1 Kg/kkg
0.036 Kg/kkg
0.12 Kg/kkg
6-9
Monthly Average
5.3 Kg/kkg
2.9 Kg/kkg
0.011 Kg/kkg
0.036 Kg/kkg
6-9
BAT effluent limitations for existing sources for discharges resulting from the production of
hydrofluoric acid include (40 CFR 415.83):
Pollutant
Total Fluorine
Total Nickel
Total Zinc
Dally Maximum
3.4 Kg/kkg
0.020 Kg/kkg
0.072 Kg/kkg
Monthly Average
1.6 Kg/kkg
0.0060 Kg/kkg
0.022 Kg/kkg
Effluent limitations for new sources of these discharges include (40 CFR 415.85):
Pollutant
Total Suspended Solids
Total Fluorine
Total Nickel
Total Zinc
pH
Dally Maximum
6.0 Kg/kkg
3.4 Kg/kkg
0.020 Kg/kkg
0.072 Kg/kkg
6-9
Monthly AWTBQO
3.0 Kg/kkg
1.6 Kg/kkg
0.0060 Kg/kkg
0.022 Kg/kkg
6-9
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Chapter 9: Hydrofluoric Acid Production 9-19
In Texas and Louisiana, states which do not have EPA-approved NPDES programs, EPA Regional
personnel have stated that they would apply the above guidelines. The State, however, may also adopt state
water quality standards for control of discharges from hydrofluoric acid manufacturing facilities.
9.4.2 State Regulation
The three hydrofluoric acid production facilities addressed by this report, all of which generate and
co-manage fluorogypsum and process wastewater, are located in Kentucky, Louisiana, and Texas. All three
of these states were selected for regulatory review (see Chapter 2 for a discussion of the methodology used
to select study states for detailed regulatory review).
All three states with hydrofluoric acid production facilities exclude mineral processing wastes from
hazardous waste regulation. Of the three states, Louisiana appears to be the most comprehensive in its
coverage of both fluorogypsum and process wastewater, which the state classifies as industrial solid wastes.
Although no requirements have been drafted specifically for fluorogypsum waste piles, facility owner/operators
must comply with general waste pile provisions for soils (e.g., stability, permeability), hydrologic characteristics,
precipitation run-on and run-off, location standards, security, safety, and waste characterization. Similarly,
process wastewater management must meet general industrial waste surface impoundment requirements such
as run-on controls, liner requirements, design standards (e.g., to prevent overtopping and minimize erosion),
waste characterization, and ground-water monitoring requirements. Surface impoundments must be dewatered
and clean-closed (i.e., all residuals removed) or closed according to solid waste landfill closure provisions.
Louisiana also requires that owners/operators of all industrial solid waste piles and surface impoundments
maintain financial responsibility for the closure and post-closure care of those waste units. Although
Louisiana does not have an approved NPDES program, the state does require state permits for the discharge
of leachate or run-off to surface waters. Finally, Louisiana air regulations require that its one hydrofluoric
acid processing facility manage its wastes in a manner necessary to minimize fugitive dust emissions.
As does Louisiana, Texas classifies mineral processing wastes, including wastes from the production
of hydrofluoric acid, as industrial solid wastes. Because the hydrofluoric acid facility in Texas disposes of its
wastes on property that is both within 50 miles of the facility and controlled by the facility owner/operator,
the state has not required the facility to obtain a solid waste disposal permit. The facility has notified the state
of its waste disposal activities, as required, and has obtained federal NPDES and Texas wastewater discharge
permits. Finally, Texas air regulations include provisions that could apply to the disposal of hydrofluoric acid
processing wastes, though it does not appear that these provisions have been applied to the facility.
Kentucky also classifies the hydrofluoric acid processing wastes generated at its one facility as solid
waste and requires the facility to maintain a solid waste permit that includes provisions for ground-water
monitoring and waste characterization. The facility's surface impoundment is not designed to discharge to
either ground or surface water. Kentucky's facility also maintains a NPDES permit, though state officials
believe that all of the process wastewater is recycled at the facility, and must meet stormwater run-off standards
for both its operating and closed fluorogypsum ponds. The state recently proposed a new residuals regulation
that may apply to hydrofluoric acid processing wastes. If these wastes are subject to the new rule, the facility
owner/operator could be required to upgrade existing ground-water monitoring efforts, continue waste
characterization, undenake the formal closure of waste management units, and demonstrate financial
responsibility. Finally, although general fugitive dust emission control requirements apply, the nature of
fluorogypsum as it is currently managed at the facility effectively precludes fugitive dust problems and state
officials were unaware of any such problems.
In summary, all three states with hydrofluoric acid processing facilities exclude the fluorogypsum and
process wastewaters generated at those facilities from hazardous waste regulation. Moreover, all three states
address these wastes under their solid waste regulations to varying degrees. Of the three states, Louisiana
currently appears to be the most comprehensive in its regulation under solid waste provisions. Kentucky
applies some regulatory controls to its facility and appears to be preparing to strengthen those requirements
under a recently promulgated residuals regulation. Texas classifies hydrofluoric acid processing wastes as solid
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9-20 Chapter 9: Hydrofluoric Acid Production
wastes, but exempts its facility from the requirement to obtain a solid waste disposal permit because the wastes
are disposed of on-site. All three facilities maintain federal and/or state NPDES permits. Finally, although
all three states have general fugitive dust emission control provisions, none of the states appear to have
applied those requirements to hydrofluoric acid processing wastes because of the nature of fluorogypsum and
process wastewater.
9.5 Waste Management Alternatives and Potential Utilization
This section provides a brief summary of current management practices and potential areas of
utilization for both fluorogypsum and process wastewater, because they are generally co-managed.
Fluorogypsum
In 1988V the three U.S. facilities generated an estimated 890,000 metric tons of fluorogypsum.40 The
primary alternative to disposal of fluorogypsum in stacks is utilization in construction materials as a
lightweight aggregate. Two of the three facilities sell fluorogypsum from their stacks to on-site contractors
who subsequently sell it to construction firms and highway departments. The third facility disposes of all of
its fluorogypsum. This facility (Attochem's facility in Calvert City, Kentucky) currently disposes of all its
fluorogypsum in a surface impoundment, though the firm is currently investigating the possibility of utilizing
the fluorogypsum to produce a road base aggregate.41
Allied Signal's Geismar, Louisiana plant sent over 323,000 metric tons of fluorogypsum to its disposal
stack in 1988 and removed and sold 140,000 metric tons.42 Louisiana Synthetic Aggregate, an on-site
contractor, retrieves the fluorogypsum from the stack, screens and sizes it, adds a quantity of reagent to the
product for neutralization, and sells the fluorogypsum to construction companies and local highway
departments for use as a lightweight aggregate in road beds.43 There has been one reported damage case
associated with use of fluorogypsum without neutralization from Allied's facility as an embankment material
(see Section 9.3.2 for details). Louisiana Synthetic Aggregate is investigating the use of fluorogypsum in
building materials (i.e., plaster of Paris, self-leveling sub-floor base) as a substitute for natural gypsum.44
Of the three U.S. facilities generating fluorogypsum, the duPont plant in LaPorte, Texas has had the
greatest success in selling its fluorogypsum for utilization in construction. duPont sells its fluorogypsum to
an on-site contractor, Gulf States Materials, which markets the product in the Houston area. The sales to
production ratio for duPont's fluorogypsum in 1988 and 1989 were 153 percent and 161 percent, respectively.
Approximately 60 percent of the material sold is used as a limestone replacement for road base aggregate and
40 percent is used as a fill material. Except for screening and sizing, the fluorogypsum sent to the stack at
the LaPorte facility does not require any processing before being utilized. If the material is used as road base,
cement or fly ash may be added to give it pozzollanic characteristics. DuPont expects that the market for
fluorogypsum as a construction material will continue to grow as it has in the 11 years since the material was
first sold.45
* Company responses to the "National Survey of Solid Wastes from Mineral Processing Facilities,'' U.S. EPA, 1989.
41 Pennwalt Corporation, company response to the "National Survey of Solid Wastes form Mineral Processing Facilities," U.S. EPA,
1989.
42 Allied-Signal, Inc., company response to the "National Survey of Solid Wastes form Mineral Processing Facilities," U.S. EPA, 1989.
43 Personal communication, Dennis Cheuvront, Environmental Supervisor, Allied-Signal Inc., Geismar, Louisiana, May 11,1990.
44 JbW.
45 Personal communication, Larry Schwarz, Staff Engineer-HF Operation, E.I. DuPont, LaPorte, Texas, May 10, 1990.
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Chapter 9: Hydrofluoric Acid Production 9-21
Hydrofluoric Acid Process Wastewater
At present, the only waste management practices being applied by the three hydrofluoric acid
producers to the process wastewater are returning it to the production process and/or adjusting the pH prior
to recycling or discharge. None of the three facilities report that they completely neutralize their process
wastewater, and in some cases the recycled wastewater is used because of its acidity.46 Therefore, the only
potential waste management alternative is complete neutralization, though this might reduce the quantity of
wastewater that can be recycled.
9.6 Costs and Economic Impacts
Section 8002(p) of RCRA directs EPA to examine the costs of alternative practices for the
management of the special wastes considered in this report. EPA has responded to this requirement by
evaluating the operational changes that would be implied by compliance with three different regulatory
scenarios, as described in Chapter 2. In reviewing and evaluating the Agency's estimates of the cost and
economic impacts associated with these changes, it is important to remember what the regulatory scenarios
imply, and what assumptions have been made in conducting the analysis.
The focus of the Subtitle C compliance scenario is on the costs of constructing and operating
hazardous waste management units. Other important aspects of the Subtitle C system (e.g., corrective action,
prospective land disposal restrictions) have not been explicitly factored into the cost analysis. Therefore,
differences between the costs estimated for Subtitle C compliance and those under other scenarios (particularly
Subtitle C-Minus) are less than they might be under an alternative set of conditions (e.g., if most affected
facilities were not already subject to Subtitle C, if land disposal restrictions had been promulgated for "newly
identified" hazardous wastes). The Subtitle C-Minus scenario represents, as discussed above in Chapter 2, the
minimum requirements that would apply to any of the special wastes that are ultimately regulated as hazardous
wastes; this scenario does not reflect any actual determinations or preliminary judgments concerning the
specific requirements that would apply to any such wastes. Further, the Subtitle D-Plus scenario represents
one of many possible approaches to a Subtitle D program for special mineral processing wastes, and has been
included in this report only for illustrative purposes. The cost estimates provided below for the three scenarios
considered in this report must be interpreted accordingly.
In accordance with the spirit of RCRA §8002(p), EPA has focused its analysis on impacts on the firms
and facilities generating the special wastes, rather than on net impacts to society in the aggregate. Therefore,
the cost analysis has been conducted on an after-tax basis, using a discount rate based on a previously
developed estimate of the weighted average cost of capital to U.S. industrial firms (9.49 percent), as discussed
in Chapter 2. Waste generation rate estimates (which are directly proportional to costs) for the period of
analysis (the present through 1995) have been developed in consultation with the U.S Bureau of Mines.
In this section, EPA first outlines the way in which it has identified and evaluated the waste
management practices that would be employed under different regulatory scenarios by facilities producing
hydrofluoric acid. Next, the section discusses the cost implications of requiring these changes to the existing
waste management practices. The last part of the section discusses and predicts the ultimate impacts of the
increased waste management costs faced by this industry.
9.6.1 Regulatory Scenarios and Required Management Practices
Based upon the information presented above, EPA believes that process wastewater from hydrofluoric
acid production may pose a relatively high risk potential and generally exhibits that hazardous waste
characteristic of corrosivity. Accordingly, the Agency has estimated the costs associated with RCRA Subtitle C
regulation, as well as with two somewhat less stringent regulatory scenarios, referred to here as
46 Company responses to the "National Survey of Solid Wastes from Mineral Processing Facilities," U.S. EPA, 1989.
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9-22 Chapter 9: Hydrofluoric Acid Production
"Subtitle C-Minus" and "Subtitle D-Plus" (a more detailed description of the cost impact analysis and the
development of these regulatory scenarios is presented in Chapter 2, above). In the following paragraphs, EPA
discusses the assumed management practices that would occur under each regulatory alternative.
The Agency's sampling efforts indicated that the process wastewater at Allied-Signal's Geismar facility
exhibits the hazardous characteristic of corrosivity. While the conservative approach would be to assume that
the remaining two facilities also generate corrosive process wastewaters, EPA believes that present practices
are such that no compliance costs would be imposed on those facilities. The Calvert City facility currently
treats its slurried fluorogypsum and process wastewater such that the wastewater leaving the treatment unit
is neutral (i.e., with pH of 8, as reported in the SWMPF Survey). The duPont facility reportedly treats its
slurried waste stream with lime to bring it to a very high pH, possibly even greater than 12.5, such that the
process water may be considered corrosive at the alkaline extreme. The purpose of this treatment is to
prepare the gypsum for sale as a byproduct. The Agency assumes that the facility would decrease the extent
of its lime treatment to the point at which the process wastewater would not exhibit the corrosivity
characteristic (pH < 12.5), and that this treatment process modification would not impose any compliance
costs per se.
Because the available data indicate that fluorogypsum does not exhibit any of the characteristics of
hazardous waste and has been found to pose only low potential risk, the issues of how waste management costs
might change because of new regulatory requirements and what impacts such costs might impose upon affected
facilities are moot Consequently, EPA has not estimated regulatory compliance costs for this waste.
A decision by EPA that Subtitle C regulation is appropriate for process wastewater would result in
incremental waste management costs at one facility. The Agency has estimated the incidence, magnitude, and
impacts of the costs for that facility, this analysis is presented in the following paragraphs.
Subtitle C
Under Subtitle C standards, hazardous waste that is managed on-site must meet the rigorous standards
codified at 40 CFR Part 264 for hazardous waste treatment, storage, and disposal facilities. Because
hydrofluoric acid production process wastewater is a dilute, aqueous liquid, that is corrosive but non-EP toxic,
the management practice of choice under Subtitle C is treatment (neutralization) in a tank. EPA has
determined that within the relevant size range, tank treatment is the least-cost management method, and has
conducted its analysis accordingly. The scenario examined here involves construction of a Subtitle C surge
pond (double-lined surface impoundment), and a tank treatment system. Following neutralization, the treated
process wastewater may be reused by the facility (e.g., to slurry fluorogypsum to the gypsum stack or
impoundment), just as it is under current practice. The treatment sludge, which is assumed to not be
hazardous, is disposed in an unlined disposal impoundment/landfill.
Subtitle C-Minus
Assumed practices under Subtitle C-Minus are identical to those described above for the full
Subtitle C scenario, with the exception that some of the strict requirements for construction and operation
of the hazardous waste surge pond have been relaxed, most notably the liner design requirements. Because
other Subtitle C provisions apply in full, there are no significant operational differences between the two
scenarios.
Subtitle D-Plus
Assumed practices under Subtitle D-Plus are identical to those described above for the full Subtitle C
scenario, with the exception that, as under Subtitle C-Minus, some of the strict requirements for construction
and operation of the hazardous waste surge pond have been relaxed, most notably the liner design
requirements. Because other Subtitle C provisions apply in full, there are no significant operational
differences between this and the other two scenarios.
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Chapter 9: Hydrofluoric Acid Production 9-23
9.6.2 Cost Impact Assessment Results
Results of the cost impact analysis for the hydrofluoric acid sector are presented by regulatory
scenario in Exhibit 9-8. Under the Subtitle C scenario, annualized incremental regulatory compliance costs
for Allied-Signal's facility are estimated to be $1.8 million greater than baseline (over 8 times the baseline
costs). Annualized incremental capital compliance expenditures are estimated at $512,000, approximately 29
percent of total incremental compliance costs.
Under the somewhat less rigorous requirements of the Subtitle C-Minus scenario, costs of regulatory
compliance are lower, due to decreased capital construction outlays. Allied-Signal's annualized compliance
costs under this scenario are estimated to be $1.7 million greater than baseline (about 8 times baseline costs).
The total compliance cost is only about four percent less than that under the full Subtitle C scenario. The
primary reason for the difference in waste management costs is the configuration of the surge pond liner
system; under the Subtitle C-Minus scenario, disposal units are equipped with a single synthetic/clay liner and
leachate collection system, rather than the dual system required under full Subtitle C regulation.
Costs under the Subtitle D-Plus regulatory scenario are virtually identical to those under Subtitle C-
minus scenario. The configuration of the surge pond, the only varying factor, is the same for D-Plus as under
C-Minus (installation of a composite liner and clean closure). Variations in permitting costs between C-Minus
and D-Plus account for the difference in the annual compliance cost.
9.6.3 Financial and Economic Impact Assessment
In order to evaluate the ability of the affected facility to bear these regulatory compliance costs, EPA
conducted an impact assessment consisting of three steps. First, the Agency compared the estimated costs to
several measures of the financial strength of the facility and thereby generated financial impact ratios in order
to assess the magnitude of the financial burden that would be imposed in the absence of changes in supply,
demand, or price. Next, in order to determine whether compliance costs could be distributed to (shared
among) other production input and product markets, EPA conducted a qualitative evaluation of the salient
market factors that affect the competitive position of domestic primary hydrofluoric acid producers. Finally,
the Agency combined the results of the first two steps to arrive at predicted ultimate compliance-related
economic impacts on the hydrofluoric acid industry. The methods and assumptions used to conduct this
analysis are described in Chapter 2.
Financial Ratio Analysis
EPA believes that regulation under any of the three scenarios would not significantly affect the
financial viability of the one affected facility, Allied-Signal's facility in Geismar, Louisiana. As shown in
Exhibit 9-9, the annualized incremental costs associated with waste management under Subtitle C, C-Minus,
or D-Plus should only marginally affect the facility in terms of both value added and value of shipments, as
indicated by ratio values of less than 1.5 percent in all cases. The only potentially significant impact is
indicated by the annualized compliance capital as a percentage of the total annual sustaining capital
investment; additional capital approaching ten percent of current levels of sustaining capital would be required
to cover increased waste management costs.
Evaluation of Cost/Economic Impacts
EPA believes that stringent regulation of hydrofluoric acid process wastewater as a hazardous waste
would not impose highly significant economic or financial impacts on Allied-Signal's facility in Geismar,
Louisiana, though a large capital investment relative to current sustaining capital would be required.
Furthermore, EPAs analysis suggests that the operator could pass through a portion of any regulatory
compliance costs to product consumers, because demand for and prices of hydrofluoric acid have been strong
in recent years, and are expected to remain so for the foreseeable future. As a final note, the Agency expects
-------
Exhibit 9-8
Compliance Cost Analysis Results for Management of
Hydrofluoric Acid Process Wastewater(a)
Facility
Allied-Signal - Oeismar, LA
Total:
Baseline Waste
Management Coat
Annual Total
($000)
236
236
Incremental Costs of Regulatory Compliance
Subtitle C
Annual
Total
($000)
1.758
1,758
Total
Capital
($000)
3.429
3.429
Annual
Capital
($000)
512
512
Subtitle C-Mlnus
Annual
Total
($000)
1,686
1.686
Total
Capital
($000)
3.046
3.046
Annual
Capital
($000)
454
454
Subtitle O-Plu*
Annual
Total
($000)
1,583
1.583
Total
Capital
($000)
3,046
3,046
Annual
Capital
($000)
454
454
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Chapter 9: Hydrofluoric Acid Production 9-25
Exhibit 9-9
Significance of Regulatory Compliance Costs for Management of
Hydrofluoric Acid(a)
Facility
Subtitle C
Allied-Signal - Geismar, LA
Subtitle C-Minus
Allied-Signal - Geismar, LA
Subtitle D-Plus
Allied-Signal - Qeismar, LA
CC/VOS
1.2%
1.1%
1.1%
CC/VA
1.5%
1.5%
1.4%
IR/K
9.7%
8.7%
8.7%
CC/VOS = Compliance Costs as Percent of Sales
CC/VA = Compliance Costs as Percent of Value Added
IR/K = Annualized Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported in this table are based upon EPA's compliance cost estimates. The Agency believes that these
values are precise to two significant digits.
Costs and impacts have been estimated for only the facility for which sampling data indicate that the waste fails a RCRA
hazardous waste characteristic.
there to be no significant difference in the cost impacts of the Subtitle C, C-Minus, and D-Plus regulatory
scenarios, suggesting that adequately protective management standards will eventually be required, irrespective
of whether process wastewater from hydrofluoric acid is retained within the Mining Waste Exclusion.
9.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) potential for and documented
danger to human health and the environment; (2) the need for and desirability of additional regulation; and
(3) the costs and impacts of potential Subtitle C regulation.
Fluorogypsum
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of fluorogypsum is relatively low compared to the other mineral processing wastes
studied in this report. Fluorogypsum does not exhibit any of the four characteristics of hazardous waste. No
constituents in the fluorogypsum solids were detected at levels above the risk screening criteria used in this
analysis, and only two constituents - gross alpha radiation and lead ~ were detected in the waste leachate in
a concentration that exceeds the screening criteria by as much as a factor of 10. Gross alpha levels as high
as 226 pCi/1 (15 times the MCL) and radium-226 levels as high as 22 pCi/1 (4 times the MCL) were measured
in leachate/run-off collected at field locations where fluorogypsum had been disposed. Information collected
through EPAs damage case research also indicates that fluorogypsum may be mildly corrosive to iron, steel,
and concrete, although not so corrosive as to qualify as a hazardous waste. This residual corrosivity is likely
the result of the fluorogypsum being co-managed with the highly acidic process wastewater, rather than an
intrinsic property of the fluorogypsum itself.
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9-26 Chapter 9: Hydrofluoric Acid Production
Based on an analysis of existing release and environmental conditions at the three active hydrofluoric
acid plants, there is a relatively high potential for fluorogypsum leachate to migrate into shallow ground water.
This is substantiated by documented leachate migration near the impoundment at the Calvert City facility.
Such migration, however, is not expected to cause significant impacts, either because the shallow ground water
is not likely to be used at close downgradient distances and contaminant concentrations at potential exposure
points should be below levels of concern (as is the case at Geismar and LaPorte), or because the waste
management units are equipped with slurry walls and a monitoring well network to detect and help contain
any ground-water contamination (as is the case at Calvert City). The potential for significant releases to
surface water during routine operations is limited at each site by some type of management control, including
perimeter ditches, automatic pumps, retention ponds, and/or slurry walls. Even if contaminants did migrate
to nearby surface waters, each of the existing sites borders major water bodies (the Mississippi River, the
Tennessee River, and San Jacinta Bay) that should be able to assimilate the low pollutant loadings that would
be expected during routine operating conditions. Contaminants from the Geismar facility may migrate into
a smaller water body, the Bayou Breaux, in the event of a large spill or gypsum stack failure, but routine
releases to this bayou are not expected. Occasional overflows and emergency discharges to surface water have
occurred during major storms, but these are generally releases of process wastewater rather than fluorogypsum.
Such emergency discharges also are isolated events that are controlled under the NPDES program. Finally,
considering the form of fluorogypsum (moist/wet solids that dry to form a surface crust) and the fact that no
contaminants were detected in the waste at levels that could pose an inhalation threat, the potential for
significant releases and exposures via the air pathway also appears low.
Through its damage case research, EPA identified two cases of documented environmental
contamination that are associated with the management of fluorogypsum. In one case, fluorogypsum was used
to construct a test highway embankment in a wetland near Amelia, LA, resulting in high contaminant
concentrations in run-off and ambient surface water at the site. This damage case demonstrates that the
distribution and use of this material warrants close control. The other damage case involves at least six
separate incidents since 1979 in which the fluorogypsum stack at the Geismar facility has physically failed (i.e.,
slumped, collapsed, and/or overflowed). In each incident, localized environmental contamination has occurred,
but this contamination appears to be more attributable to the process wastewater that was spilled along with
the stack failure than to the fluorogypsum.
Likelihood That Existing Risks/Impacts Will Continue in the Absence of Subtitle C Regulation
As discussed above, the current fluorogypsum management practices and environmental conditions
at the three active hydrofluoric acid production facilities may allow leachate from this waste to migrate into
shallow ground water, both now and in the future. This potential for migration exists partly because the
existing fluorogypsum management units are not lined and are underlain by shallow ground water, and partly
because fluorogypsum is co-managed with highly acidic (or basic) process wastewater that can mobilize metals
in the gypsum and provide a hydraulic head to drive contaminants into the subsurface. After closure, and if
the process wastewater is removed, the potential for leachate migration from this waste will be reduced
considerably. This migration is not expected to pose a significant human health and environmental threat at
present for the reasons outlined above, and considering the measured contaminant concentrations in
fluorogypsum leachate, would pose a hazard in the future only if shallow ground water very near the waste
management units is allowed to be used for drinking or agricultural purposes.
There is a relatively high potential for fluorogypsum to be generated and managed at alternate sites
in the future. Acid-grade fluorospar that is used as a feedstock is largely imported, such that additional plants
could be located nearly anywhere that provides adequate access to water transportation. Although the addition
of new plants is uncertain, it is a distinct possibility given that many potential chlorofluorocarbon (CFC)
-------
Chapter 9: Hydrofluoric Acid Production 9-27
substitutes are likely to require more fluorine than do CFCs.47 In addition, two of the three active facilities
currently sell fluorogypsum to construction firms and highway departments for use at off-site locations. As
demonstrated by the damage case in Amelia, LA such off-site uses can lead to damages if not properly
controlled. However, given the low intrinsic hazard of fluorogypsum, damages from off-site uses are likely only
in extreme mismanagement scenarios, such as disposal of the material in a wetland (as was the case at Amelia)
or disposal in a manner that would allow people to drink largely undiluted leachate.
At present, of the three states with hydrofluoric acid processing facilities, Louisiana appears to be the
most comprehensive in its regulation of fluorogypsum under its solid waste provisions. Fluorogypsum is
classified as an industrial solid waste in Louisiana, and although the gypsum is not subject to specific
requirements, stacks must meet the State's general requirements for solid waste landfills. Owners/operators
in Louisiana also must maintain Federal NPDES permits and State air emission permits, the latter of which
include provisions for fugitive dust control. The other states where active facilities are located - Kentucky
and Texas - impose less stringent solid waste and air regulatory requirements on hydrofluoric acid production
facilities within their jurisdictions, though Kentucky recently proposed new solid waste regulations that may
address the waste more stringently.
Costs and Impacts of Subtitle C Regulation
Because of the low risk potential of fluorogypsum, the general absence of documented damages
associated with the appropriate use of this material, and the fact that this waste does not exhibit any
characteristics of hazardous waste, EPA has not estimated the costs and associated impacts of regulating
fluorogypsum from hydrofluoric acid production under RCRA Subtitle C
Hydrofluoric Acid Process Wastewater
Potential and Documented Danger to Human Health and the Environment
In contrast to fluorogypsum, the intrinsic hazard of hydrofluoric acid process wastewater is relatively
high compared to the other mineral processing wastes studied in this report. All nine samples of process
wastewater that were analyzed (from two of the three active facilities) exhibited the hazardous waste
characteristic of corrosivity - the pH may be as low as 1 at the Geismar and Calvert City facilities, and as high
as 14 at the LaPorte facility. In addition, the wastewater contains six constituents in concentrations that
exceed the risk screening criteria used in this analysis by a factor of 10, though none of the constituents were
detected in excess of the EP toxicity regulatory levels.
Because the process wastewater is co-managed with fluorogypsum, the potential for wastewater to
migrate into the environment at the active facilities is similar to that described above for fluorogypsum.
However, the extreme pH and higher concentrations of toxic constituents in process wastewater make it a
greater potential threat than fluorogypsum. There is a relatively high potential for process wastewater to
migrate into shallow ground water at the three facilities, as demonstrated by the contaminant migration
observed near the impoundment at the Calvert City facility and the contamination seeps observed around the
process wastewater clearwell pond at the Geismar facility. This migration is not expected to pose significant
current health risks, either because the shallow ground water is not likely to be used at close downgradient
distances (as is the case at Geismar and LaPorte), or because the waste management units are equipped with
slurry walls and a monitoring well network to detect and help contain ground-water contamination (as is the
case at Calvert City). However, the very low or high pH of the process wastewater could cause considerable
ground-water resource damage (e.g., affected ground water may be corrosive, have an objectionable taste, and
require additional treatment prior to use). Routine operations are not expected to cause significant surface
47 Production of CFCs is being phased out due to their adverse effects on stratospheric ozone. Substitute compounds that are less
persistent in the atmosphere are expected to have more fluorine atoms per molecule, thus increasing demand for a source of fluorine in
the production of these compounds.
-------
9-28 Chapter 9: Hydrofluoric Acid Production
water impacts, considering the management controls, distances to surface water, and assimilative capacity of
nearby waters. Nevertheless, as demonstrated by the damage case at the Geismar facility, there may be
occasional spills and emergency discharges of process wastewater that may kill vegetation on affected land and
cause short-term pH excursions in surface waters (such emergency discharges are controlled under the NPDES
program). Airborne releases and risks associated with the management of process wastewater are not expected
to occur, given the physical state of this waste stream.
Likelihood That Existing Risks/Impacts Will Continue in the Absence of Subtitle C Regulation
Current process wastewater management practices may allow seepage into ground water, both now
and in the future, because the existing waste management units are not lined and are underlain by shallow
ground water. The co-management of process wastewater with fluorogypsum enhances the potential for
contaminant migration because the highly acidic process wastewater percolating through the fluorogypsum may
mobilize metals in the gypsum and provide a force to carry contaminants into the subsurface. In addition,
there are difficulties in preventing the physical failure of gypsum stacks. Although rare, these stack failures
allow large spills of the process wastewater and intense localized impacts. These releases are expected to
continue in the absence of more stringent regulation, and although EPA does not believe that they have
caused significant long-term risks at the active facilities, significant exposures could occur if the wastewater
is managed in a more sensitive environmental setting in the future. In addition, the corrosive nature of the
wastewater would likely render affected ground water near the waste management units unfit for future uses
without prior treatment.
While process wastewater is not likely to be used off-site, there is a potential for new hydrofluoric
acid production plants to start up at alternate sites in the future. As discussed above for fluorogypsum, more
plants may be needed to produce the more fluorine-rich substitutes for CFCs. If constructed, these new plants
may be located in environmental settings where the corrosive wastewater may pose substantial risks if not
properly controlled.
Finally, of the three States where the active facilities are located, Louisiana appears to be most
comprehensive in its regulation of hydrofluoric acid process wastewater. The process wastewater is classified
as an industrial solid waste in Louisiana, and although the wastewater is not subject to specific requirements,
the wastewater impoundments must meet general requirements for all surface water impoundments.
Owners/operators in Louisiana also must maintain Federal NPDES permits for the discharge of process
wastewater. In contrast, Kentucky and Texas (the other States where active facilities are located) impose less
stringent requirements on hydrofluoric acid production facilities, though Kentucky recently proposed new solid
waste regulations that may address process wastewater more directly.
Costs and Impacts of Subtitle C Regulation
Because of the relatively high risk potential of this waste and the fact that EPA waste sampling data
indicate that process wastewater from hydrofluoric acid production exhibits the hazardous waste characteristic
of coirosivity, the Agency has evaluated the costs and associated impacts of regulating this waste as a
hazardous waste under RCRA Subtitle C However, information collected by EPA indicates that at two of
the three active facilities (LaPorte and Calvert City), neutralization of the process wastewater (i.e., removal
of the characteristic of hazardous waste) is part of the current management practice. Consequently, EPA
believes that removal of process wastewater from the Mining Waste Exclusion would not impose significant
operational or cost impacts on these two facilities. Therefore, EPA's analysis of costs and impacts is limited
in scope to the Geismar facility.
Total costs of regulatory compliance at the Geismar hydrofluoric acid plant exceed $1.5 million
annually under each of the three regulatory scenarios. Costs under the full Subtitle C, Subtitle C-Minus, and
Subtitle D-Plus scenarios are similar (within nine percent of one another), because adequately protective waste
management unit design and operating standards are essentially the same under all three scenarios, given the
nature of the waste and the environmental setting in which it is currently managed. These compliance costs
-------
Chapter 9: Hydrofluoric Acid Production 9-29
represent 'from one to one and one half percent of the value of shipments of and value added by the Geismar
facility, though the annualized capital requirements of compliance are on the order of nine to ten percent of
the sustaining capital required for the hydrofluoric acid operation. EPA's economic impact analysis suggests
that the operator of the potentially affected facility could pass through a portion of any regulatory compliance
costs that they might incur to product consumers, because demand for and prices of hydrofluoric acid have
been strong in recent years, and are expected to remain so for the foreseeable future. Because the costs of
Subtitle C regulatory compliance would not impose significant immediate impacts on the affected facility (less
than one and a half percent of value added), because the facility may have some ability to pass any such costs
through to product consumers through higher prices, and perhaps most importantly, because two of the three
active facilities in the sector currently treat their process wastewater in the manner contemplated here, EPA
does not believe that a decision to regulate process wastewater from hydrofluoric acid production under
Subtitle C would threaten the long-term profitability or viability of the Geismar facility, or any other future
hydrofluoric acid plant.
Finally, EPA is not aware of any significant recycling or utilization initiatives that would be hampered
by a change in the regulatory status of this waste. At the one potentially affected facility, the process water
is likely to be managed in much the same way as it is currently, with the exception that it would be treated
prior to discharge. EPA does not believe that the additional waste management requirements would materially
affect the production processes employed at or general operation of the affected facility.
-------
Chapter 10
Primary Lead Processing
The primary lead processing sector consists of five facilities that, as of September 1989, were active
and reported generating a special mineral processing waste: slag from smelting and refining. One facility
conducts only smelting, a second only refining, and the other three conduct both operations, as is shown in
Exhibit 10-1. The bullion from the East Helena smelter is refined at the Omaha refinery, which also processes
secondary materials.1 The data included in this section are discussed in additional detail in a technical
background document in the supporting public docket for this report.
Exhibit 10-1
Primary Lead Processing Facilities
Operator/Owner
ASARCO
ASARCO
ASARCO
Doe Run/Fluor Corp.w
Do« Run/Fluor Corp.**
Location
East Helena, MT
Glover, MO
Omaha, NE
Boss, MO
Herculaneum, MO
Type of Operation
Smelter
Smelter and Refinery
Refinety
Smelter and Refinery
Smelter and Refinery
w
Bureau of Mines, 1990. Personal communication with BOM Commodity Specialist, 27 June.
10.1 Industry Overview
The primary domestic use of lead is in lead-acid storage batteries. Lead is also used in containers and
as an additive for gasoline, though these uses are rapidly declining.2 Lead also is used to manufacture lead
oxides which are used in the battery, glass, ceramics, rubber, and coatings industries.3
Three of the five facilities are located in Missouri, one is in Montana, and the other is in Nebraska.
The dates of initial operation for these facilities range from 1879 to 1968. Four of the facilities were
extensively modernized between 1967 and 1988; the fifth, the Boss, MO facility, which was new in 1968,
reportedly has not undergone extensive modernization and is operating intermittently at less than 10 percent
of capacity. The three ASARCO facilities have designated their aggregate annual lead refining production
capacity, production, and capacity utilization data from the SWMPF Survey as confidential.4 The Bureau of
Mines reports that the estimated production of refined lead from primary processing was 392,000 metric tons
1 In addition to toe five primary facilities, approximately SO secondary processing facilities are operating; the operations conducted at
these facilities, however, fall outside EPA's established definition of primary mineral processing and accordingly, do not generate special
mineral processing wastes. (See 54 FR 36619-36620, September 1,1989.)
2 Bureau of Mines, 1987. Minerals Yearbook. 1987 Ed., p. 544.
3 Bureau of Mines, 1985. Mineral Facts and Problems. 1985 Ed., p. 439.
4 ASARCO and Doe Run, 1989. Company Responses to the "National Survey of Solid Wastes from Mineral Processing Facilities,"
U.S. EPA, 1989.
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10-2 Chapter 10: Primary Lead Processing
in 1988;5 in the SWMPF Survey, Doe Run reported its 1988 production from its Boss and Herculaneum
smelter/refineries as 10,000 and 225,000 metric tons., respectively.
The U.S. Bureau of Mines estimates that after a sharp decline between 1985 and 1986, the quantity
of refined lead produced in the U.S. has slowly but steadily increased from 370,000 metric tons in 1986 to
395,000 metric tons in 1989. With the increasing production rate, the U.S. became a significant lead
concentrate exporter in 1989. Recent expansion in the primary lead industry consists of a large new smelting
and refining facility coming on-line in late 1989. In addition, mines in Alaska, Idaho, Missouri, and Montana
were newly opened, re-opened, or expanded during the late 1980s.6
The Bureau estimates that primary smelter production will remain at about 400,000 metric tons in
1990. Domestic consumption of lead is expected to decline slightly in 1990, but, on a worldwide scale, this
decrease in consumption is expected to be offset somewhat by increased demand in Asia and, to a lesser extent,
in Europe.7 U.S. output of refined lead is expected to increase slightly in 1990, although this increase should
be due entirely to secondary lead output.8 Future growth in the lead market depends highly upon the level
of growth and new developments in the transportation, electrical, and electronics industries.9
The sector wide capacity of primary refined lead (i.e., the capacity of the ASARCO/East Helena
smelter is not included because all product is sent to a separate refinery) is estimated to be 577,000 metric tons
per year. Long-term capacity utilization (i.e., from 1990 to 1995), as reported by the Bureau of Mines, is
expected to range from 100 percent at the Glover and Herculaneum facilities to 80,50, and 20 percent at the
East Helena, Omaha, and Boss facilities, respectively.
Primary lead processing consists of both smelting (blast furnace and dross furnace operations) and
refining operations, as shown in Exhibit 10-2. In the smelting process, sintered ore concentrate is introduced
into a blast furnace along with coke, limestone, and other fluxing materials; the lead is reduced, and the
resulting molten material separates into four layers: lead bullion (98 wt. percent lead); "speiss" and "matte,"
two distinct layers of material which contain recoverable concentrations of copper, zinc, and minor metals; and
blast furnace slag.10 The speiss and matte are sold to copper smelters for recovery of copper and precious
metals; the blast furnace slag is stored in piles and partially recycled (at the three Missouri facilities) or
disposed (at the Montana facility). The lead bullion is then drossed (i.e., agitated in a dressing kettle and
cooled to just above its freezing point) to remove lead and other metal oxides, which solidify and float on the
molten lead bullion. The solidified material (referred to as dross), which is composed of roughly 90 percent
lead oxide, along with copper, antimony, and other elements, is skimmed off the bullion and fed to a dross
furnace for recovery of the non-lead mineral values. About 50-60 percent of the recovery furnace output is
slag and residual lead that are both returned to the blast furnace. The remainder of the dross furnace output
is sold to copper smelters for recovery of the copper and other precious metals. The lead bullion may also
be decopperized before being sent to the refining plant.
Lead refining operations continue the process of removing various saleable metals (e.g., gold and
silver, bismuth, zinc, and metal oxides such as antimony, arsenic, tin, and copper oxide). These operations,
which are described in detail in the technical background document, are softening, desilverizing, dezincing, and
bismuth removal In the final refining step the lead bullion is mixed with fluxes to remove remaining
impurities (e.g., calcium, magnesium, and lead oxide). Reagents (e.g., caustic soda and/or nitrates) may be
5 Bureau of Mines, 1990. Personal communication with BOM Commodity Specialist.
* William D. Woodbuiy, 1990. U.S. Bureau of Mines, "Lead," Mineral Commodity Summaries. 1990 Ed., pp. 91, 96, 97.
7 Alan S. Kafka, 1990. "Lead: Tight Market Possible; 121st Annual Survey and Outlook," EAMJ. March, p. 24.
8 Ibid., p. 23.
9 Ibid.
10 Environmental Protection Agency, 1984. Overview of Solid Waste Generation. Management, and Chemical Characteristics in the
Primary Lead Smelting and Refining. Prepared by PEI Associates for U.S. EPA, Office of Research and Development, Washington, D.C,
December.
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Chapter 10: Primary Lead Processing 10-3
Exhibit 10-2
Primary Lead Processing
PROCESS
Sinter Plant
(Beneficiation)
SPECIAL WASTE
MANAGEMENT
StorogeA
Disposal I
Disposal
Legend
I 1 Production Operation C.—x Special Waste
\_/
Waste Management Unit
added to the lead, which is then cooled, causing the impurities to rise to the surface and be removed. This
refining residue is returned directly to the blast furnace at the Missouri facilities (the three integrated smelter/
refinery operations) and, therefore, is not a solid waste at these facilities. The refinery "slag" generated at the
stand-alone refinery in Nebraska is not recycled, but discarded as a solid waste. The refined lead is then cast
into ingots.
10.2 Waste Characteristics, Generation, and Current Management Practices
The special mineral processing waste, slag, generated by primary production of lead is generated as
a molten mass. The slag may be "hot-dumped" onto a waste pile to form large solid chunks or granulated with
a water jet to form fine, sand-sized particles. As reported in the SWMPF Survey and indicated by EPAs
sampling results, lead slag is composed primarily of iron and silicon oxides, as well as aluminum and calcium
oxides. Other metals may also be present in smaller amounts, including antimony, arsenic, beryllium,
cadmium, chromium, cobalt, copper, lead, manganese, mercury, molybdenum, silver, and zinc.11'12
Using available data on the composition of lead slag, EPA evaluated whether the slag exhibits any
of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and extraction procedure (EP)
toxicity. Based on available information and professional judgment, EPA does not believe the slag is corrosive,
reactive, or ignitable, but some slag samples do exhibit the characteristic of EP toxicity. EP leach test
11 EPA, 1989. "National Survey of Solid Wastes from Minenl Processing Facilities."
12 EPA, 1989. "Waste Sampling Data."
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10-4 Chapter 10: Primary Lead Processing
concentrations of all eight inorganic constituents with EP toxicity regulatory levels are available for lead slag
from all five facilities of interest. Of these constituents, arsenic, cadmium, lead, mercury, and selenium
concentrations were found to sometimes exceed the EP regulatory levels, with all five facilities having an
exceedance for at least one of these constituents. Lead concentrations exceeded the EP level at every facility
and in a total of 27 out of 101 samples; the maximum lead concentration exceeded the EP level by a factor
of 19. Cadmium concentrations in 7 out of 99 samples (from two facilities) exceeded the EP level by as much
as a factor of 8. Arsenic, mercury, and selenium concentrations exceeded the EP level at only one facility,
ASARCO in Omaha, ME. However, arsenic and selenium exceeded the level in roughly 27 out of 94 samples
from the Omaha facility by as much as a factor of 1,400 and 180, respectively. Mercury concentrations at the
Omaha plant exceeded the level in 79 out of 94 samples by as much as a factor of 8. Two of the slag samples
that failed the EP toxicity level for lead were also analyzed using the SPLP leach test, and for both of these
samples, the concentration of lead measured using the SPLP test was at most 0.7 times the EP toxicity
regulatory level.
Blast furnace slag is generated at four facilities; the fifth facility (Omaha, NE) generates waste slags
from refining (e.g., exchange kettle and cupola furnace slag) in quantities about two orders of magnitude
smaller than the other facilities (actual volume is confidential). For purposes of this report, as established
during the reinterpretation rulemaking process, the slag generated at all five facilities, including Omaha's
refinery slags, are considered slag from primary lead processing. Refinery slags at the three Missouri facilities,
as well as slag from the smelters' dross furnaces, are not included in EPA's analyses, as these slags are directly
recycled to the production process and are, therefore, not considered solid wastes.
Only one fully operational lead facility reported non-confidential waste generation data; Doe Run/
Herculaneum reported generating 220,000 metric tons of slag in 1988, with a waste-to-product ratio of 0.97.
EPA estimates the long term annual waste generation rate for the entire sector to be 469,000 metric tons per
year. For the three fully operational facilities with smelter operations (i.e., one standby facility, Doe Run/Boss,
and one stand-alone refinery, ASARCO/Omaha, are excluded), the annual generation rate is estimated to be
448,000 metric tons for an average of nearly 150,000 metric tons per facility and a waste-to-product ratio of
1.10. The refinery slag at Omaha is not recycled as is refinery slag at the integrated facilities and is, therefore,
considered a waste; the estimated generation rate is 8,000 metric tons per year with a waste-to-product ratio
of 0.11.
The predominant waste management practice used at the five lead facilities is to return a majority
of the furnace slag (73 and 64 percent at the Doe Run facilities) to the sinter plant and stockpile the
remainder. The East Helena smelting facility reported stockpiling all slag on-site; its Omaha refinery reported
landfilling all slag off-site. Based on responses to the SWMPF Survey, the total volume of slag accumulated
on-site for four lead smelting facilities is approximately 2.7 million metric tons; quantities range from 430,000
to 1360,000 metric tons at the four smelters. (No slag reportedly accumulates at the Omaha refinery.)
The average dimensions of the slag piles at the four smelting facilities with on-site piles are 30300
square meters (7.5 acres) of basal area and 10.5 meters (35 feet) of height; on a facility-specific basis the basal
areas range from 20,200 to 48,500 square meters and the height from six to 18 meters. Three of the four
smelter facilities with large slag piles report that these slag piles are lined with in-situ day, the fourth is
unlined. The Omaha refinery uses three small concrete-lined storage piles to hold slag before shipment off-
site; the three piles range from 68 to 230 square meters in basal area and 1.5 to 3 meters in height
Two facilities reported monitoring ground water around their slag piles, while a third reported
monitoring only surface water. One facility reported having run-on/run-off controls; another facility reported
using dust suppression but did not describe the practice; and a third facility reported that it collects and
manages leacbate from the slag pile.
-------
Chapter 10: Primary Lead Processing 10-5
10.3 Potential and Documented Danger to Human Health and the Environment
This section addresses two of the study factors required by §8002(p) of RCRA: (1) potential danger
(i.e., risk) to human health and the environment; and (2) documented cases in which danger to human health
or the environment has been proved. Overall conclusions about the hazards associated with lead slag are
provided after these two study factors are discussed.
10.3.1 Risks Associated With Lead Slag
Any potential danger to human health and the environment from lead slag depends on the presence
of toxic constituents in the slag that may pose a risk and the potential for exposure to these constituents.
These factors are discussed separately below, followed by EPAs risk modeling results for lead slag.
Constituents of Concern
EPA identified chemical constituents in lead slag that may pose a risk by collecting data on the
composition of lead slag and evaluating the intrinsic hazard of the slag's chemical constituents.
Data on Lead Slag and Leachate Composition
EPAs characterization of lead slag and its leachate is based on data from three sources: (1) a 1989
sampling and analysis effort by EPAs Office of Solid Waste (OSW); (2) industry responses to a RCRA §3007
request in 1989; and (3) sampling and analysis conducted by EPAs Office of Research and Development
(ORD) in 1984. These data provide information on the concentrations of some 20 metals, sulfate, and fluoride
in total solids and leach test samples.
These sources provide data on the composition of slag solids at all but one of the five primary lead
processing facilities (Boss, MO). Concentrations in total samples of the lead slag are generally within two
orders of magnitude for most constituents across all data sources (i.e., EPA and RCRA §3007 responses) and
facilities. A notable exception is that concentrations of antimony, arsenic, and silver for the Omaha facility
are more than three or four orders of magnitude higher than concentrations of these constituents in slag from
any of the other facilities. This difference probably occurs because the Omaha facility, which provided the
data, is the only facility that generates refinery slag but no smelter slag.
Data from leach test analyses are available for all five facilities. With a few exceptions, concentrations
from leach test analyses of the slag generally are within two orders of magnitude across the data sources (Le.,
OSW, ORD, and industry), types of leach tests (EP, SPLP, and TCLP), and facilities.
Process for Identifying Constituents of Concern
As discussed in Section 2.2.2, the Agency evaluated the waste composition data summarized above
to determine if lead slag contains any chemical constituents that may pose an intrinsic hazard, and to narrow
the focus of the risk assessment The Agency performed this evaluation by first comparing constituent
concentrations to conservative screening criteria and then by evaluating the environmental persistence and
mobility of constituents that are present at levels above the criteria. These screening criteria were developed
using assumed scenarios that are likely to overestimate the extent to which lead slag constituents are released
to the environment and migrate to possible exposure points. For example, EPA evaluated the potential for
chemicals to pose an inhalation risk by assuming that dust from the slag is blown into the air, when in fact
the panicle size of most slag is such that it would not become airborne. As a result, this process eliminates
from further consideration those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic ecosystems, and air and surface/ground-water resources (see Exhibit 2-3). Given the
conservative (i.e., protective) nature of these screening criteria, contaminant concentrations in excess of the
-------
10-6 Chapter 10: Primary Lead Processing
criteria should not, in isolation, be interpreted as proof of hazard. Instead, exceedances of the criteria indicate
the need to evaluate the potential hazards of the waste in greater detail.
Identified Constituents of Potential Concern
Exhibits 10-3 and 10-4 summarize the frequency with which the chemical constituents of lead slag
exceed the risk screening criteria. Data are provided in the exhibits for all constituents that are present in
concentrations that exceed a screening criterion.
Exhibit 10-3 identifies constituents in lead slag that are present in concentrations that exceed the
screening criteria based on the total sample analysis results from EPA and industry sampling. As shown, eight
of the more than 20 constituents analyzed in the slag solids were deteaed in concentrations that exceed human
health screening criteria: arsenic, cadmium, chromium, lead, selenium, antimony, silver, and zinc. All of these
constituents are persistent in the environment (i.e., they do not degrade). Arsenic and lead exceeded the
criteria most frequently and by the widest margins. For example, both of these constituents exceeded the
screening criteria in roughly 90 percent or more of all samples analyzed from at least half of the facilities.
Arsenic, lead, chromium, and antimony exceeded the screening criteria by more than a factor of 10 in at least
one sample. These exceedances indicate the potential for two types of impacts, as follows:
• Arsenic, lead, antimony, silver, and zinc concentrations may cause adverse health effects
if a small quantity of the slag or soil contaminated with the slag is inadvertently ingested
over a long period of time, which could occur if public access to the slag piles is not
restricted.
Exhibit 10-3
Potential Constituents of Concern in Lead Slag Solids^
Potential
Constituents
of Concern
Lead
Arsenic
As iliHiQny
Zinc
Cadmium
Chromium
Selenium
Silver
No. of Time*
Constttuent
Detected/No, of
Analyses
for Constituent
153/183
13/15
1«/1«
81/81
8/65
1/4
i/a
142/145
Human Health
Screening Criteria"*'
Ingesfion
Ingestion*
Inhalation*
1H066DOI1
InQMtion
lnV*J*elji_i«*
* HiCwHUKMi
Inhalation*
Inhalation
Ingestion
HO. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
153/153
13/15
13/15
14/1S
2/81
4/65
1/4
t/3
6/145
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
4/4
2/4
2/4
2/4
2/4
1/3
1/3
1/3
1/4
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10"5 lifetime cancer
risk; others are based on noncancer effects.
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Chapter 10: Primary Lead Processing 10-7
Exhibit 10-4
Potential Constituents of Concern in Lead Slag Leachate(a>
Potential
Constituents
of Concern
Lead
Cadmium
Araenic
Zinc
Iron
Cobalt
Copper
Manganese
Mercury
Selenium
Silver
Antimony
No. of Time*
Constituent
Detected/No, of
Analyses
for Constituent
101 / 101
97/99
87/96
16/16
12/14
2/3
10 n*
14/14
83/94:
79/93
79/64
74/76
Screening Criteria04
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health*
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
Human Health
Aquatic Ecological
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
72/101
94/101
61/101
14/99
17/99
17/99
87/96
44/96
31 /96
5/16
5/16
13/16
7714
2/14
2/3
r/ie
1/14
8/14
1/14
79/94
78/94
81/94
25/92
46/92
26/92
d/94
64/76
10/76
No. of Facilities
Exceeding Criteria/
No. of Facilities
. Analyzed for
Constituent
5/5
5/5
5/5
5/5
5/5
5/5
5/5
1 /5
1 /5
3/4
3/4
4/4
4/4
2/4
2/3
3/S
1 /4
4/4
1 /4
1/5
1/5
2/5
1 /5
1/5
1 /5
1 /5
1 /4
1 /4
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. Unless otherwise
noted, the constituent concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer risk or noncanoer health effects. 'Human health* screening criteria
noted with an •*• are based on a 1x10* lifetime cancer risk; others are baaed on noncancer effects.
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10-8 Chapter 10: Primary Lead Processing
• Selenium, arsenic, chromium, and cadmium may pose a health threat if slag dust is
blown into the air and inhaled in a concentration that equals the National Ambient Air
Quality Standard for paniculate matter. However, as discussed in more detail in the
section on Air Release, Transport, and Exposure Potential, the particle size distribution
of lead slag and the distance to potential receptors significantly limits the potential for
such large exposures to dust from slag piles.
Lead concentrations in 26 of 153 samples of the slag solids (from two of four facilities) also exceeded
the air resource damage screening criterion. This suggests that lead concentrations could be high enough to
cause an exceedance of the National Ambient Air Quality Standard for lead if slag dust is blown into the air
in a concentration that equals the air quality standard for particulates matter. Again, the extent to which dust
is actually blown into the air from slag piles is limited by the relatively large size of lead slag particles.
Exhibit 10-4 identifies the constituents that exceed the screening criteria based on leach test data from
EPA and industry.13 As shown, 12 constituents were detected in lead slag leachate in concentrations that
exceed risk screening criteria for water-based release and exposure pathways. All of these constituents are
inorganics that do not degrade in the environment In general, arsenic, lead, and mercury exceeded the criteria
most frequently (in at least 90 percent of the samples from at least half of the facilities). The arsenic and lead
concentrations also exceeded the screening criteria by the widest margins (up to a factor of 1,000 or more).
As discussed previously, arsenic, lead, cadmium, mercury, and selenium were also measured in EP leachate in
concentrations that exceeded the EP toricity regulatory levels.
These exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• Arsenic, cadmium, lead, selenium, antimony, zinc, and mercury concentrations in the
slag leachate may pose a health risk if the leachate is released to ground water, diluted
by a factor of 10 during migration to a downgradient drinking water well, and ingested
over a long period of time.
• If the slag leachate is released to ground or surface water, arsenic, cadmium, lead,
selenium, cobalt, iron, manganese, zinc, and mercury concentrations could render the
water unsuitable for a variety of uses (e.g., irrigation, direct human consumption of the
water, or human consumption of fish that live in affected water bodies).
• Concentrations of arsenic, cadmium, lead, selenium, antimony, silver, copper, iron, zinc,
and mercury in the slag leachate may present a threat to aquatic organisms if the
leachate migrates (with a 100-fold dilution) to surface waters.
These exceedances, by themselves, do not prove that the slag poses a significant risk, but rather
indicate that the slag may present a hazard under a very conservative, hypothetical set of release, transport,
and exposure conditions. To determine the potential for this waste to cause significant impacts, EPA
proceeded to the next step of the risk assessment to analyze the actual conditions that exist at the facilities
that generate and manage the slag.
Release, Transport, and Exposure Potential
This analysis evaluates the baseline hazards of lead slag as it was generated and managed at the five
active facilities in 1988. Lead slag is primarily disposed on-site (i.e., at four of five facilities) and the slag is
not currently used off-site, although several options for off-site utilization are available (see Section 10.5).
This analysis does not assess the hazards of off-site disposal of slag from the Omaha facility because of a lack
of data on the management practices and environmental conditions of the off-site disposal facility. Instead,
this analysis evaluates hazards posed by the storage of slag at the Omaha facility prior to its transport off-site.
0 For the purpose of this analysis, comparison of teach test data to screening criteria rely on EP leach test results. Results from the
SPLP leach test identified the same constituents of concern as the EP leach test, though the results from the two leach tests differ
somewhat in terms of the magnitude with which constituent concentrations exceed the screening criteria.
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Chapter 10: Primary Lead Processing 10-9
The following analysis also does not consider the risks associated with variations in waste management
practices or potentially exposed populations in the future because of a lack of data adequate to predict future
conditions.
Ground-Water Release, Transport, and Exposure Potential
As discussed in the preceding section, EPA and industry test data show that several constituents are
capable of leaching from lead slag in concentrations above the screening criteria. However, considering the
existing slag management practices and neutral pH conditions that are expected, only arsenic, cadmium,
selenium, cobalt, and mercury are likely to be mobile in ground water if released. Exhibit 10-5 summarizes
the key factors at each lead facility that affect the potential for these constituents to be released into ground
water and cause impacts through that pathway.
Releases to ground water at the East Helena, MT smelter, the Glover, MO facility, and the Boss, MO
facility are considered possible because ground-water monitoring near the slag piles at each of these sites has
identified contamination that may be attributable to the slag. (See the damage case study findings in Section
10.3.2 for more discussion of this observed contamination.) The releases at Glover and Boss may have been
facilitated by the karst and dolomite that underlie these sites. These earth materials are prone to develop
solution cavities that can permit the ready transport of ground-water contaminants. The East Helena facility
is in an area that has a very low natural net recharge to ground water, less than 1 cm/yi. However, any
ground-water contamination that can be attributed to the slag pile at this site could have been caused by the
former practice of sprinkling contaminated wastewater on the pile to control dust. There are also wastewater
ponds near the slag pile at East Helena that appear to be primary contributors to ground-water contamination
at this site. Ground water in the vicinity of each plant is used as a drinking water supply, and residences that
could have drinking water wells are located only 180 meters downgradient from the East Helena smelter and
980 meters downgradient of the Boss facility. The distance between the slag pile at Glover and the nearest
downgradient residence that could have a well is not known, but the nearest property boundary in a
downgradient direction (where the ground water conceivably could be withdrawn for drinking) appears to be
at least 600 meters from the pile.
Although ground-water monitoring data are not available for the Herculaneum facility and the Omaha
refinery, the potential for releases to ground water and subsequent exposures at these sites is reduced by a
number of site-specific factors.
• The on-site slag pile at the Herculaneum facility is underlain by in-situ clay. The
uppermost useable aquifer is deep, roughly 80 meters below the land surface, and the
primary earth materials separating the slag pile from this useable aquifer are relatively
impermeable clays and silts. The net recharge in the area of the Herculaneum facility
is very low, about 2 cm/yr, meaning that relatively little precipitation is available to seep
through the pile and carry slag contaminants to the subsurface. Ground water in the
area is used as a municipal drinking water supply, but there currently are no down-
gradient drinking water wells within 1,600 meters (1 mile).
• Ground water beneath the Omaha refinery is very shallow, only 2 meters beneath the
land surface. However, release from the three, relatively small slag piles to ground
water is limited by management practices (Le., use of concrete pits for slag storage) and
a low net recharge (5 cm/yr). There are no known uses of ground water in the area, and
there are no downgradient drinking water wells within 1,600 meters (1 mile) of the site.
If leachate from the slag piles at the Herculaneum and Omaha facilities did seep into ground water,
it could restrict potential ground-water uses in the future, but it would not pose a current health threat
considering the large distances to existing drinking water wells.
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10-10 Chapter 10: Primary Lee °rocesslng
Exhibit 10-5
Summary of Release, Transport, and Exposure Potential
for Lead Slag
Facility
Release, Transport, and Exposure Potential
Proximity to
Sensitive Environments
BOSS
Ground Water: Releases limited by in-situ clay liner, leachate
collection system, large depth to useable aquifer (45 m), imper-
meable subsurface, and low net recharge (5 cm/yr); contamination
that may be attributable to the slag pile has been detected, al-
though this contamination may have been caused by two unlined
wastewater impoundments next to the pile; nearest downgradient
drinking water well is 980 meters away.
Located in a National
Forest
Surface Water: High annual precipitation (98 cm), impermeable
subsurface, and steeply sloped land (6-12%) create the potential for
surface erosion; run-off from the slag pile, however, is collected and
treated; Crooked Creek is located 1,100 m away; no consumptive
uses of creek within 24 km, but low flow (16 mgd) indicates little
potential for dilution and possible aquatic ecological risks.
Air: Releases not controlled by dust suppression; wind erosion
and dumping operations could lead to potential inhalation ex-
posures at the nearest residences located 915 m from facility; 1,800
people Irving within 8 km (5 miles).
HERCULANEUM
Ground Water; Releases limited by in-situ clay liner, large depth to
useable aquifer (80 m), impermeable subsurface, and low net
recharge (2 cm/yr); no drinking water wells within 1.6 km (1 mile)
downgradient
Surface Water: High annual precipitation (94 cm), impermeable
subsurface, and moderate topographic slope (up to 6%) create
potential for surface erosion; Mississippi River is close (within 90
m), but Its very large flow (100,000 mgd) yields significant dilution;
no consumptive uses of riVer within 24 km.
Air: Releases not controlled by dust suppression; wind erosion
and slag dumping could lead to airborne dust and Inhalation
exposures at the nearest residence Just 15 m from facility; 25,000
people living within 8 km (5 miles).
Located in a 100-year
floodplain and within
1.6 km of a wetland
EAST HELENA
Ground Water Pile is not lined, useable aquifer is shallow (4 m
deep), and subsurface is permeable; although net recharge is low
(< 1 cm/yr), former practice of sprinkling pile with wastewater for
duet suppression may have led to ground-water contamination;
observed contamination Is mainly attributed to two unlined im-
poundments, not the slag pile; potential drinking water exposure at
residence as close as 180 m downgradient
Surface Water Surface erosion limited by low annual precipitation
(29 cm) and gentte topographic slope (< 2%); Prickly Pear Creek
located just 56 m downgradient; although no consumptive uses of
creek within 24 km, the creek's low How (26 mgd) allows little
dilution and possible aquatic ecological risks.
Ajr Releases not controlled by dust suppression, and monitoring
has detected exceedance of air quality standard for lead; potential
inhalation exposures at residences located as dose as 180 m from
facility and potential food chain exposures through deposition of
paniculate matter on surrounding agricultural fields; approximately
12,000 people living within 8 km (5 miles).
Located in a 100-year
floodplain, a wetland, and
a fault zone
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Chapter 10: Primary Lead Processing 10-11
Exhibit 10-5 (cont'd)
Summary of Release, Transport, and Exposure Potential
for Lead Slag
Facility
Release, Transport, and Exposure Potential
Proximity to
Sensitive Environments
OMAHA
Ground Water: Although ground water shallow (2 m deep),
releases limited by concrete liners and low net recharge (5 cm/yr);
no drinking water wells within 1.6 km (1 mile) downgradient.
Surface Water: Moderate annual precipitation (76 cm), low net
recharge, moderate topographic slope (up to 6%), and short
distance to Missouri River (60 m) create surface water con-
tamination potential; however, river's large flow (18,000 mgd)
provides for significant dilution and there are no consumptive uses
within 24 km.
Air: Releases controlled by dust suppression, decreasing release
potential; if airborne releases, potential inhalation exposures at
residences located as close as 1,100 m from facility; roughly
224,000 people living within 8 km (5 miles).
Located in a 100-year
floodplain and a fault
zone, and within 1.6 km
of a wetland
GLOVER
Ground Water: Although releases limited by irvsitu clay liner,
stormwater run-on/run-off controls, impermeable subsurface, and
low net recharge, monitoring has identified ground-water con-
tamination; ground water is used for drinking in the area, but the
nearest property boundary in downgradient direction (where water
could be withdrawn) is 600 m from slag pile.
Surface Water: Existing ground-water contamination, high annual
precipitation (105 cm) and moderate distance to Scrogg.ns Branch
that discharges into Big Creek (244 m) create contamination
potential; however, run-off from the slag pile is now collected and
treated prior to discharge; creek not used for consumptive uses
within 24 km, but its moderate flow (80 mgd) allows only moderate
dilution and possible aquatic ecological risks; monitoring has
identified contamination possibly attributable to slag pile.
Air: Releases not controlled by dust suppression; wind erosion
and slag dumping could lead to airborne dust and inhalation
exposures at residences as close as 60 m from facility; only 840
people live within 8 km (5 miles).
Located in a National
Forest and an area of
karst terrane
Surface Water Re/ease, Transport, and Exposure Potential
The primary pathways for lead slag contaminants to enter surface waters are migration in a leached
form through ground water that discharges to surface water, and direct overland run-off via storm water
erosion either in a leached form or in the form of solid particles. The high concentrations of several
constituents detected in slag leachate tests confirm that the potential exists for slag contaminants to migrate
into surface water in a leached form. The physical form of the slag, however, being relatively large particles
ranging from sand-size (0.2 to 2 mm) to boulders (larger than 0.3 meters or 12 inches), should help limit the
overland run-off of slag solids. Only particles that are 0.1 mm or less in size tend to be appreciably erodible,
and only a very small fraction of the slag solids are expected to be in this size range.
Exhibit 10-5 summarizes the characteristics of each of the five lead facilities that affect the surface
water release, transport, and exposure potential of lead slag. Based on an analysis of these characteristics, it
is possible for slag contaminants to be released to surface water at all five facilities. In fact, an inspection
report indicates that the slag pile at the Boss facility may be a source of surface water contamination and
contaminated run-off that may discharge into surface water has been observed at the Glover and East Helena
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10-12 Chapter 10: Primary Lead Processing
facilities (see the damage case study findings discussion below). All of the slag piles are located within 1,100
meters of a river or creek, with Herculaneum, East Helena, and Omaha being within 100 meters of a water
body. The Herculaneum, East Helena, and Glover facilities are also within 100-year floodplains. and although
remote, the possibility of large releases from the slag piles caused by floods at these sites cannot be dismissed.
In addition, all but the East Helena smelter are located in areas with relatively high annual precipitation (76
to 105 cm/yr) that could cause significant run-off. The only facilities that use storm water run-on/run-off
controls at their slag piles are the Boss and Glover facilities.
Although there appears to be a potential for release at all lead facilities, the potential for significant
surface water contamination appears to be greatest at the Boss, East Helena, and Glover facilities (depending
on the efficiency of the storm water run-on/run-off controls at Boss and Glover). The creeks/rivers near these
facilities are relatively small to moderate in size, with an average annual flow that ranges from 16 to 81 mgd.
These relatively low flows provide a limited dilution capacity compared to that provided by rivers near
Herculaneum and Omaha, which have an average annual flow of 100,000 mgd and 18,000 mgd, respectively.
These large flows should allow for significant dilution of any contamination released from the slag piles.
Furthermore, none of the creeks or rivers located near the lead facilities are currently used for drinking water
or any other consumptive purpose within 24 km (15 miles). Therefore, any contamination originating from
the slag piles would not pose a current health risk through surface water, though it could pose an aquatic
ecological risk and render the water less suitable for potential future uses.
Air Re/ease, Transport, and Exposure Potential
Because the constituents that exceed the screening criteria are nonvolatile, lead slag contaminants can
only be released to air in the form of dust particles. The particles can be either blown into the air by wind
or suspended in air by slag dumping and loading operations. Factors that affect the potential for such airborne
releases include the particle size of lead slag, the height and exposed surface area of the slag piles, the slag
moisture content, the use of dust suppression controls, and local wind speeds. The potential for exposure to
airborne dust depends on the proximity of the slag piles to people and agricultural lands.
The relatively large size of lead slag particles limits the potential for release of airborne dust. In
general, particles that are <. 100 ^m (0.1 mm) in diameter are wind suspendable and transportable. Within
this range, however, only panicles that are <. 30 pm in diameter can be transported for considerable distances
downwind, and only particles that are <. 10 jim in diameter are respirable. As mentioned previously, lead slag
particles range from sand-size (0.2 to 2 mm) to boulders (larger than 30 cm). Therefore, the vast majority of
the slag should not be suspendable, transportable, or respirable. It is likely that only a very small fraction of
the slag will be weathered and aged into smaller particles that can be suspended in air and cause airborne
exposure and related impacts.
The height and exposed area of the slag piles, the slag moisture content, the use of dust suppression
controls, wind speeds, and the proximity of the slag pile to people vary on a site-specific basis, as follows:
• At the Boss facility, the slag pile is approximately 20,000 square meters (5 acres) in area
and 6 m high. The pile is not covered with either vegetation or a synthetic material.
The facility does not use any dust suppression controls, such as sprinkling water on the
pile, and the number of days with rain, which may suppress dust, is small (73 days/yr).
As a result, the surface slag is expected to be dry most of the time. Although short
term gusts of strong winds inevitably occur, average wind speeds range from 2.3 to 4
m/s, which are strong enough to produce wind erosion of any fine particles on the
surface of the slag pile. The nearest residence in a predominant wind direction is
approximately 915 meters away and there are roughly 1,800 people living within 8 km
(5 miles).
• The slag pile at the Herculaneum facility covers an area of 49,000 square meters (12
acres), is 8 m high, and is uncovered. The slag is expected to be dry most of the time
because no dust suppression sprinkling is conducted and the number of days with
precipitation is small (85 daystyr). Average wind speeds range from 3.6 to 5.5 m/s,
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Chapter 10: Primary Lead Processing 10-13
although there are short-term gusts of stronger winds. The nearest residence is very
close, only 15 meters downwind, and the surrounding population within 8 km is large,
approximately 25,000 people.
• The slag pile at the East Helena facility covers an area of 20,000 square meters (5
acres), is 11 meters high, and is uncovered. Although the pile is not currently watered
for the purpose of dust suppression, there is a relatively large number of days that have
a small amount of precipitation (155 days/yr) that should help keep the slag moist part
of the time. Average wind speeds range from 2.3 to 4.7 m/s, although stronger winds
occur on a short term basis. Ambient air quality monitoring in the vicinity of the pile
has identified an exceedance of the air quality standard for lead, and plant personnel
have indicated that the slag pile is a contributor to this contamination. The nearest
residences are located 180 meters downwind and there are roughly 12,000 people that
live within 8 km (5 miles). In addition, there is a potential for food chain exposures
caused by the deposition of airborne particulates on agricultural fields that are near the
facility.
• At the Omaha facility, there are three relatively small slag piles that are all less than 3
m high and cover a combined area of less than 12,000 square meters (3 acres).
Although there is a small number of days of precipitation to help keep dust down (98
days/yr), the facility practices dust suppression. The nearest residence in a predominant
wind direction is located 1,100 meters downwind. The plant is located in a densely
populated area, with approximately 224,000 people Irving within 8 km.
• The slag pile at Glover covers 32,000 square meters (8 acres), is 18 m high, and is
uncovered. The slag is expected to be dry most of the time because no dust suppression
sprinkling is conducted and the number of days with precipitation is small (80 days/yr).
Considering the average wind speeds (2.6 to 4.4 m/s) and the potential for short-term
gusts of stronger winds, wind erosion is possible. Although the nearest residence in a
predominant wind direction is only 60 meters downwind, the plant is located in a
sparsely populated area: 840 people live within 8 km.
In summary, slag particles are generally quite large and only a very small fraction of the lead slag has
the potential to be suspended in air and transported to downwind exposure points at each of the lead facilities.
The slag piles, however, are generally large, tall, and uncovered, presenting a large exposed area from which
dust can escape. Wind speeds in the vicinity of each facility are sufficient to cause windblown dust, and dust
may also be suspended at each site by slag loading and unloading. The slag also is expected to be dry most
of the time, which facilitates dusting. In addition, all five facilities have individuals living within 1.6 km (one
mile) that could be exposed to airborne particles released from the slag piles.
Based on the evaluation of the lead slag composition presented above, constituents that could pose
a health threat by dust inhalation include arsenic, cadmium, chromium, and selenium. The particle size
distribution of lead slag, however, significantly limits the potential for constituent entrainment and transpon
to potential receptors. Among the five primary lead facilities, the potential for exposure to airborne
contaminants appears greatest at the Herculaneum facility because of the close proximity to residences. The
potential for airborne exposures appears lowest at Omaha because of the relatively small size of the slag piles
and the dust suppression controls reportedly used at that site.
Proximity to Sens/tfve Environments
As summarized in Exhibit 10-5, all of the lead facilities are located in either a vulnerable environment
or an environment that has high resource value. In particular
• The Boss and Glover facilities are located in the Mark Twain National Forest in the
Missouri Ozarks. The existing contamination that is potentially attributable to lead slag
at these sites could make the forest less desirable to use for recreational purposes.
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10-14 Chapter 10: Primary Lead Processing
• The Herculaneum, East Helena, and Glover facilities are all located in 100-year
floodplains, which creates the potential for large, episodic releases from the on-site slag
pues due to flood events.
• The Herculaneum, East Helena, and Glover facilities are also located either in or within
1.6 km (one mile) of a wetland (defined here to include swamps, marshes, bogs, and
other similar areas). Wetlands are commonly entitled to special protection because they
provide habitats for many forms of wildlife, purify natural waters, provide flood and
storm damage protection, and afford a number of other benefits.
• The East Helena and Glover facilities are located in fault zones. This creates the
potential for earthquake damage to containment systems for slag piles at these sites.
• The Glover facility is located in an area of karst terrane, characterized by sink holes and
underground cavities developed by the action of water in soluble rock (such as limestone
or dolomite). Solution cavities that may exist in the bedrock at this site could permit
any ground-water contamination originating from the slag pile to migrate in a largely
unattenuated and undiluted fashion.
Risk Modeling
Based on the preceding analysis of the intrinsic hazard of lead slag and the potential for slag
contaminants to be released into the environment, the Agency ranked lead slag as having a relatively high
potential to cause risk to human health and the environment (compared to the other mineral processing wastes
studied in this report). Therefore, EPA used the model "Multimedia Soils" (MMSOILS) to quantify the risks
associated with the lead slag contaminants, facilities, and release and exposure pathways that appear to pose
the greatest concern.
Ground-Water Risks
EPA modeled potential releases to ground water from the on-site slag piles at all five facilities of
interest. Using site-specific data with respect to contaminant concentrations, slag quantities, existing
management practices, and hydrogeologic characteristics, the Agency predicted the concentrations of arsenic,
cadm'am, selenium, cobalt, mercury, and lead in ground water at the following locations downgradient from
the slag piles: the property boundary, the nearest existing residence that could have a private drinking water
well, the nearest surface water body, and, to provide a common frame of reference across the facilities, the
distances of 50, 500, and/or 1,000 meters downgradient. EPA used median constituent concentrations
measured with the EP leach test as inputs to the model. For each constituent, the Agency compared the
predicted concentrations at the modeled locations to EPA-approved benchmarks for human health protection,
drinking water maximum contaminant levels (MCLs), and National Academy of Sciences (NAS) recommended
guidelines for irrigation and livestock waters.
At the facilities in Boss, MO, Herculaneum, MO, and Omaha, NE, the predicted contaminant
concentrations at each downgradient distance were two orders of magnitude or more below the various criteria.
The predicted concentrations of arsenic at each of the downgradient locations were so small that, if the water
was ingested, it would pose a lifetime cancer risk of less than IxlO"10 (i.e., the chance of getting cancer would
be less than one in ten billion over a 70-year lifetime). In many cases, it was predicted that the contaminants
would not migrate to the water table within the modeling horizon (200 years). Due to the low levels of
precipitation infiltrating through the piles and into ground water, the depths to ground water, the low
permeability of the underlying earth materials, and the tendency of the contaminants to bind to soil, many of
the contaminants were predicted to remain adsorbed in the unsaturated zone at these sites for more than 200
years.
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Chapter 10: Primary Lead Processing 10-15
The same overall results were predicted for the facilities in Glover, MO and East Helena, MT, with
the following exceptions:
• At the Glover facility, predicted concentrations of arsenic in ground water as far as 125
meters from the slag pile, but still on plant property, could pose a lifetime cancer risk
of 4xlO'7. Predicted arsenic concentrations at the plant boundary (estimated to be about
600 meters downgradient) would yield cancer risks of less than IxlO'10. EPA has
assumed here that the slag pile and adjacent areas in the downgradient direction are not
underlain by karst. If, however, the subsurface of these areas do contain karst, actual
ground-water contaminant concentrations could be higher than EPAs risk modeling
exercise has indicated.
• Also at the Glover facility, the predicted concentrations of cobalt in ground water
roughly 250 meters downgradient from the slag pile exceeded the NAS irrigation
guideline by as much as a factor of 7. Cobalt concentrations at the plant boundary and
beyond were estimated to be below this threshold. If water with cobalt concentrations
in excess of the NAS guideline is used continuously for irrigation, it could be toxic to
tomatoes, peas, beans, oats, rye, wheat, barley, and corn.
• Similarly, at the smelter in East Helena, MT, the predicted concentrations of cobalt in
ground water exceeded the NAS irrigation guideline by as much as a factor of 1.5 as far
downgradient as the property boundary (about 55 meters from the slag pile).
This cobalt contamination at the Glover and East Helena facilities is likely to have little practical significance
at present. Along with the fact that the contamination at Glover is likely to be confined to the plant property,
the land surrounding the Glover facility is largely forested and does not appear to be used for agricultural
purposes close to the site. Although the land surrounding the East Helena smelter is used for agriculture, a
portion of the slag pile is adjacent to Prickly Pear Creek and any cobalt contamination in the ground water
may discharge into the creek and be diluted somewhat, rather than extracted directly from the ground and used
for irrigation.
Surface Water Risks
To evaluate surface water risks, EPA estimated the concentrations of lead slag contaminants in nearby
rivers and creeks after the contaminants have been fully mixed in the water's flow. EPA considered in this
analysis the annual (chronic) loading of contaminants to rivers/creeks via ground-water seepage and erosion
from the slag piles, but did not consider larger short-term releases, such as those associated with large storms,
that could result in higher concentrations that last for shorter durations. The Agency predicted the surface
water concentrations of the following lead slag constituents: antimony, arsenic, cadmium, cobalt, iron, lead,
manganese, mercury, selenium, silver, and zinc. For each constituent, the Agency compared the predicted
concentrations to available EPA-approved benchmarks for human health protection, drinking water MCLs,
freshwater ambient water quality criteria (AWQCs) for chronic exposures, and NAS recommended guidelines
for irrigation and livestock waters. Note that the methodology used here does not account for removal of
pollutants via drinking water treatment, and thus overstates risk through this pathway. In addition, the Agency
conservatively modeled the slag piles at the Boss and Glover facilities as if they were not equiped with
stormwater run-on/run-off controls.
For the facilities located in Herculaneum, MO and Omaha, NE, the predicted concentrations of all
contaminants were at least two orders of magnitude below the various criteria. The very large flows of the
Mississippi and Missouri Rivers adjacent to these facilities were predicted to effectively dilute any
contaminants released from the on-site slag piles.
The surface water concentrations of most contaminants were also estimated to be one or two orders
of magnitude below the various criteria in the creeks near the Boss, East Helena, and Glover facilities.
However, the predicted concentrations of arsenic, lead, iron, manganese, and zinc exceeded at least one
criterion at each of these facilities. Essentially all of this contamination was estimated to be caused by erosion
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10-16 Chapter 10: Primary Lead Processing
of fine particles from the slag piles, rather than seepage of contaminants into ground water that discharges
into surface water. As shown in Exhibit 10-6:
• Estimated arsenic concentrations in the creeks nearest to the Boss, East Helena, and
Glover facilities would cause lifetime cancer risks of IxlO"5 to 5xlO~5 if ingested (i.e., the
chance of getting cancer would be at least one in 100,000 over a 70-year lifetime).
These concentrations are well below the MCL, however.
The estimated concentrations of lead in Crooked Creek near the Boss facility and Big
Creek near the Glover facility exceed the noncancer effect threshold by roughly a factor
of three. Long-term ingestion of water with this lead concentration could cause
neurotoricological effects.
• The estimated concentrations of iron, lead, and manganese in the creeks near the Boss
and Glover facilities also exceed the drinking water MCLs for these constituents. In
addition to the adverse neurotoxicologic effects of lead, such concentrations of iron and
manganese could cause objectionable tastes and cause stains.
• The estimated concentration of lead in the creeks near all three facilities and the
estimated concentration of zinc in the creeks near the Boss and Glover facilities exceed
the AWQC for these constituents. Chronic exposures to these contaminant con-
centrations could adversely affect the health of any aquatic organisms living in the
creeks. Depending on the efficiency of the stormwater run-on/run-off controls at the
Boss and Glover facilities, the slag piles at these sites are likely to cause significantly
less contamination than was predicted.
Of the constituents that were modeled, only mercury and selenium are recognized as having the
potential to biomagnify (concentrate in the tissues of organisms higher in the food chain). EPAs predicted
concentrations of mercury, however, were well below the AWQC and adverse effects due to biomagnification
are not expected. Although the selenium concentrations were also predicted to be below the AWQC, the
potential for selenium to biomagnify and cause adverse effects to wildlife at higher trophic levels cannot be
ruled out (the selenium AWQC does not account for biomagnification). Mercury, cadmium, selenium, zinc,
and, to a lesser extent, arsenic may bioaccumulate in the tissue of freshwater fish that may be ingested by
humans. However, even if an individual ingests 6.5 grams of fish14 from the contaminated water every day
of the year for 70 years, cancer risks would be less than 7 x 10*7 and the doses of noncarcinogens would be
below adverse effect thresholds.
As discussed in the preceding section on potential release, transport, and exposure pathways, none
of the creeks near the Boss, East Helena, and Glover facilities are currently used as drinking water supplies
within 24 km of the sites. Therefore, the predicted contaminant concentrations in these creeks are not
expected to pose a current drinking water threat, but may present a hazard if the waters are ever used for
drinking in the future.
Air Rltkt
EPA modeled the release and inhalation of windblown dust from the slag piles at four of the five
facilities: Glover, East Helena, Boss, and Herculaneum. At each facility, the Agency predicted risks caused
by windblown arsenic, cadmium, chromium, selenium, and lead, which are the primary slag constituents that
exceed the screening criteria through the air pathway based on the preceding analysis of the slag's composition.
The Agency did not predict air pathway risks at the Omaha facility because that facility suppresses dust from
the on-site slag piles. In general, the Agency's modeling approach was very conservative (i.e., tending to
overpredict air pathway risks) because it was based on the assumption that there is an unlimited reservoir of
fine particles that can be blown into the air from lead slag piles. As discussed
14 This is a typical daily fish intake averaged over a year (EPA, Risk Assessment Guidance for Superfund. Volume I, Human Health
Evaluation Manual (Pan A), EPA/540/1 -89/002, December 1989).
-------
Chapter 10: Primary Lead Processing 10-17
Exhibit 10-6
Surface Water Risk Estimates for Lead Slag(a)
Parameter/Constituent
Distance to water
Cancer Risk
Arsenic
Ratio of Concentration to
Noncancer Threshold
Lead
Ratio of Concentration
to MCU(C)
Iron
Lead
Manganese
Ratio of Concentration
to AWQCs(d>
Lead
Zinc
Facility Location**
Boss, MO
1,097m
5x10*
2.9
2.1
12.4
1.8
19.3
3.8
East Helena, MT
55m
1 x 10'5
0.2
0.3
0.7
0.1
1.1
0.5
Glover, MO
244 m
1 x 10'5
2.6
1.8
11.2
1.5
17.5
3.3
(a) Values in this exhibit are based on constituent concentrations after complete mixing in the receiving water body. Results
are provided for only those constituents that were predicted to exceed a criterion. The predicted concentrations of ail other
constituents that were modeled (cadmium, cobalt, mercury, selenium, silver, and antimony) were one to two orders of
magnitude below the criteria.
(b) The prediced surface water concentrations of all constituents that were modeled were at least two orders of magnitude
below the criteria at the facilities in Herculaneum, MO and Omaha, NE EPA conservatively modeled the slag piles at the
Boss and Glover facilities as If they were not equipped with stormwater run-on/run-off controls. Depending on the efficiency
of these control systems, the slag piles at these sites are likely to cause significantly less contamination than was predicted.
(c) The proposed revised primary maximum contaminant level for lead, and the secondary maximum contaminant levels for
iron and manganese.
(d) The freshwater ambient water quality criteria for chronic exposures, designed to protect the health of aquatic organisms.
previously, lead slag actually has limited wind erosion potential, as it consists of a mixture of small particles
and large chunks that consume much of the wind's shear stress.
Even with this conservative approach, risks caused by the inhalation of dust from lead slag piles were
predicted to be very low at all four facilities. In particular, at the nearest residences in predominant wind
directions (the maximum exposed individual) at each site:15
• The total lifetime cancer risk caused by the inhalation of arsenic, cadmium, and
chromium (conservatively assumed to exist in the carcinogenic hexavalent form) ranges
from < IxlO'10 at the Boss, MO facility to <9xlO'7 at the facility in Herculaneum, MO.
The highest cancer risks were predicted at the Herculaneum facility because the
maximum exposed individual at this site lives only 15 meters from the slag pile.
u The appnxdmate distance from the slag pile to the maximum exposed individual is 915 meters at the Boss facility, 15 meters at the
Herculaneum facility, 180 meters at the East Helena Utility, and 60 meters at the Glover facility.
-------
10-18 Chapter 10: Primary Lead Processing
• The predicted concentrations of selenium in the air were more than two orders of
magnitude below the threshold concentration that is associated with dermatitis and
gastrointestinal tract disturbances.
• The predicted concentrations of lead in the air were more than two orders of magnitude
below the National Ambient Air Quality Standard.
EPA also estimated inhalation risks in the middle of population centers near the- East Helena and
Herculaneum facilities (the Glover and Boss facilities are located in sparsely populated areas with roughly 840
and 1,800 people currently living within 8 km (5 miles) of each of these plants, respectively). Approximately
7,700 people live between 1.6 km and 8 km to the west of the East Helena facility, and EPA's estimate of
cancer risk caused by the inhalation of lead slag dust at the center of this population area is approximately
5xlO'10. Similarly, roughly 12,000 people live between 1.6 km and 8 km to the south and south-southwest of
the Herculaneum facility; the inhalation of lead slag dust in the middle of this population center poses a
cancer risk of less than 7xlO'9. The predicted concentrations of selenium and lead in the air at the population
centers near both of these facilities were also well below the hazard criteria, as they were at the nearest
residences.
10.3.2 Damage Cases
State and EPA regional files were reviewed in an effort to document the environmental performance
of lead slag waste management practices at all four active lead smelters: ASARCO in East Helena, Montana;
ASARCO in Glover, Missouri; Doe Run in Herculaneum, Missouri; and Doe Run's Buick smelter in Boss,
Missouri. No documented environmental damages associated with the slag piles were identified for the
Herculaneum facility, based on the limited monitoring data available for this site. The two ASARCO facilities
and the Boss, Missouri facility were found to have documented exceedances of drinking water standards or
water quality criteria in ground or surface waters that have been caused at least in part by the lead slag piles
at the facilities. Two additional facilities, ASARCO in El Paso, Texas, and Midvale Slag in Midvale, Utah,
have combined lead, copper, and zinc slags on site which have resulted in documented environmental damages.
Each of the six sites identified with documented damages is discussed below.
ASARCO, East Helena, Montana
This facility, which started operation in 1888, is located immediately adjacent to the town of East
Helena, five miles east of Helena, and covers approximately 32 hectares (80 acres). Numerous private wells
surrounding this facility are used as sources of drinking water.16
The smelter currently produces lead bullion that is shipped to the ASARCO facility in Omaha, where
it is further refined. An on-site zinc fuming operation further refined the lead slag from 1927 until 1982.
Through this process, zinc was recovered by injecting air into the molten lead slag and recovering zinc oxide.
ASARCO suspended operation of the zinc fuming department in 1982 because it was uneconomical. More
than six million tons of fumed slag has been placed on 11 hectares (28 acres) along the northeastern boundary
of the plant property. Beginning in 1982, ASARCO placed the unfumed slag in a segregated area adjacent
to the fumed slag piles. The 300,000 tons of unfumed slag covers about 18,000 square meters (4.5 acres). Up
until January 1989, the unfumed slag was poured in molten form on a slag pile adjacent to the plant.
ASARCO currently air cools the slag in steel vessels before disposal.
Initial evidence of contamination originating from the slag piles was found in 1979, when a Montana
Department of Health and Environmental Sciences (MDHES) inspector reported water seeps flowing from
the slag piles into an adjacent creek. The inspector described the seeps as "a grayish steaming flow discharging
to the creek at an estimated 2 cfs." The inspector also noted that the discharge 'appeared to be flowing from
under the slag piles at ASARCO." As shown in Exhibit 10-7, these seeps were found to contain elevated levels
" ASARCO. 1986. Draft Report on Water Resources Monitoring - Aurco East Helena Plant
-------
Chapter 10: Primary Lead Processing 10-19
Exhibit 10-7
Results of Surface Water Sampling and Analysis
ASARCO, East Helena, Montana
Sampling Date
ABOVE SLAG PILE
10/24/80
10/23/80
10/23/80
10/24/80
Prickley Pear Creek
Above ASARCO Dam
Prickley Pear Creek
Above Green Discharge
Prickley Pear Creek
Below Green Discharge
Prickley Pear Creek
Below Green Discharge
DISCHARGE FROM SLAG PILE
02/19/80
03/05/80
03/11/80
Seep from Slag Pile
Seep from Slag Pile
Seep from Slag Pile
BELOW SLAG PILE SEEPS
10/15/79
10/31/79
Prickley Pear Creek
Above Main Discharge
Prickley Pear Creek
Above Main Discharge
BELOW SLAG PILE AND MAIN FACILITY DISCHARGE
11/01/79
11/01/79
Prickley Pear Creek
Below both Discharge Points
Prickley Pear Creek
Below both Discharge Points
BELOW SLAG PILE AND BOTH FACILITY DISCHARGES
10/15/79
10/31/79
Prickly Pear Creek
Below Main Discharge
Prickly Pear Creek
Below Main Discharge
Parameter (mg/L)
Pb
<0.03
<0.05
0.05
<0.05
0.07
<0.05
0.05
<0.05
<0.05
0.12
0.12
<0.05
<0.05
As
020(a)
0.20
2.02
0.075
80
70
Z§
0.04
0.08
3.65
3.65
0.04
0.90
Cu
0.01
0.01
0.01
0.01
0.04
0.01
0.11
0.02
0.01
0.02
0.02
0.01
0.01
Zn
0.29
0.34
0.37
0.34
0.06
0.04
0.08
0.15
0.11
020
0.20
0.16
0.14
Cd
<.005
0.01
0.04
<0.005
-
-
<0.005
0.004
<0.005
0.03
003
0.004
0.01
Mn
0.34
0.25
0.27
0.29
0.26
0.18
0.24
-
-
-
-
-
-
(a) The concentrations which are underlined represent exceedances of the MCL, based on the National Primary Drinking Water
Regulations.
of arsenic and lead. Samples of the seep water showed arsenic concentrations from 70 to 80 mg/L. The
MDHES states that years of mining in the Prickley Creek headwaters has yielded arsenic levels above MCLs
upstream from the plant site.17 Monitoring data from the creek did not show a definite increase in in-stream
concentrations of arsenic. As reponed by MDHES, the seeps were caused by ASARCO's practice of spraying
the pile with contaminated watewater for the purpose of dust control. The discharge to the creek from the
seeps was eliminated when ASARCO ceased sprinkling the slag with wastewater.18
17 Montana Department of Health and Environmental Science*, 1990. Letter from G. Mullen to K. McCarthy, ICF Incorporated, Re:
Comments on E. Helena and Anaconda Facilities. May.
18 Montana Department of Health and Environmental Sciences, 1960. Laboratory Analysis from Slag Pile, and Preliminary
Investigation Notes for Slag Pile.
-------
10-20 Chapter 10: Primary Lead Processing
This facility was listed on the Superfund National Priorities List (NPL) in 1983. Areas of the site
identified as requiring study included process water .ponds, slag piles, and areas with elevated levels of heavy
metals in the soils. Tb facilitate these studies, the site was divided into five "operable units," one of which
consists of the slag piles.19
Although a documented link has not been established, the slag piles have also been considered by
ASARCO as potential sources of ground-water contamination. A ground-water monitoring investigation
completed by ASARCO on February 7,1986 indicated that concentrations of some heavy metals and arsenic
in surface and ground-water exceeded drinking water standards. Specific data were not provided. All potential
sources of contaminants were identified, and the list included the unfumed slag pile and the fumed slag
pile.20 Elevated levels of arsenic (up to 0.620 mg/L), zinc (up to 3.7 mg/L), and sulfates (up to 11,750 mg/L)
were measured in 1987 by ASARCO in water from within the slag piles.21 Ground-water monitoring data
from 1986 discussed in the 1987 Remedial Investigation for this site showed that monitoring wells
downgradient of two process wastewater impoundments and the slag pile "have elevated concentrations of
sulfate and arsenic."22 However, site maps showing the locations of the arsenic and sulfate plumes reveal
that the contamination has been caused mainly by the wastewater impoundments, not the slag pile.
While two of the three wells downgradient of the slag pile showed elevated levels of arsenic,
manganese and sulfate, the upgradient well also showed elevated levels of these contaminants. Exhibit 10-8
provides the results of these analyses. This upgradient well is located in the area influenced by seepage from
the wastewater impoundments.
ASARCO, Glover, Missouri
ASARCO's Glover lead smelter is situated in a lead-rich region known as Missouri's "Old Lead Belt,"
within the Mark Twain National Forest in the Missouri Ozarks. ASARCO began operations at this facility
in 1968. Slag generated by the smelter is stored in an on-site pile which is upslope and upgradient of the
facility. Wastewater discharges (NPDES), surface run-off; and ground-water flow from the facility are all
directed towards or into Big Creek. Although no documentation was found directly stating that the lead slag
piles were the source of heavy metals releases to surface or ground waters, some of the data reviewed suggest
that the lead slag is at least part of the source.
In May 1985, ASARCO conducted a hydrologic characterization of the Glover facility. Data from
this study showed that, in contrast to background or upgradient samples, elevated cadmium, zinc, manganese,
and possibly chromium concentrations were present in many surface and ground-water samples collected
downgradient of the lead slag pile. (See Exhibit 10-9.) Cadmium concentrations exceeded the MCL by a
significant amount in bedrock wells (0.027 - 0.053 mg/L) and shallow wells (0.52 - 2.3 mg/L), as well as surface
waters (0.52 - 4.3 mg/L) downgradient of the slag.
Manganese and zinc were also present in the shallow wells and surface water downgradient from the
slag pile.23 Background values for the deep aquifer were not available.
19 EPA Region VIII and Montana Department of Health and Environmental Science*, 1989. Superfund Program Proposed Plan - East
Helena Smelter Site.
20 ASARCO, 1986. Draft Report on Water Resources Monitoring - Asarco East Helena Plant
21 ASARCO, 1986. Test Hole Logs performed for Asarco by Hydrometrics and miscellaneous sample results from Asarco tests.
n CH2M Hill, 1987. East Helena Smelter (Asarco) Site Profile.
0 ASARCO, 1990. Letter from OP. Lubbers, ASARCO Glover, to D. Bussard, EPA Headquarters, Waste Management Division,
Re: (None) Response to data request.
-------
Chapter 10: Primary Lead Processing 10-21
Exhibit 10-8
Results from Groundwater Quality Analysis
ASARCO, East Helena, Montana
Sampling
Dale
01/06/85
01/18/85
01/18/85
06/11/85
Well
Namew
DH-e*'
DH-7*1"
DH-IO*1
Dh-9(c|
Parameter (mg/L)
Pfo
<0.005
< 0.005
< 0.005
0.007
As
M""
0.005
5.10
10.4
Cu
0.013
<0.008
0.009
0.010
S04
545<«>
74.7
352
415
Cd
<0.001
<0.001
0.003
0.006
Mn
0.054
0.041
4.80
0.463
(a) It appears that most of the private wells in East Helena are drilled at depths ranging from 10 to 49 meters. Thus, it can
reasonably be expected that the depth to groundwater for the above wells is similar.
(b) Based on potentiometric surface maps of the site, these sampling points appear to be downgradient of the slag pile.
(c) Based on the same maps mentioned above, it appears that this sampling point is upgradient of the slag pile.
(d) The concentrations which are underlined represent exccedances of the National Primary Drinking Water Regulations.
(e) The concentrations in bold (not underlined) represent exceedances of the National Secondary Drinking Water
Regulations.
Exhibit 10-9
Summary of Exceedances from Well and Surface Water Analyses
ASARCO, Glover, Missouri
Station"1
Deep Aquifer
Downgradient
103D
Shallow Aquifer
Upgradient
101
102
Downgradient
MW-4
103
104
105
MW-3
Scroggins Branch
300
301
Slag Seep
303
Total No.
Samples®
3
6
6
6
3
6
6
6
5
6
6
Cd
2/5.3
0
0
6/230
3/4.5
6/57
0
3/1.7
0
1/12
6/430
Fe
0
0
0
1/2.1
0
6/6.8
0
0
0
0
0
Mn
0
0
0
5/2.4
0
6/9.9
4/2.3
0
0
0
1/126
} MCI/Maximum Excsedanee Factor®
Pb
2/1.4
1/1.4
0
3/2.4
0
1/1.6
1/1.6
3/1.6
0
1/1.6
6/5.6
Zn
0
0
0
2/1.86
0
0
0
0
0
0
5/7.14
TDS
3/4.04
0
0
6/4.01
3/1.88
5/229
0
0
0
0
6/2.65
S04
3/4.52
0
0
6/4.76
3/1.82
3/2.41
0
0
0
0
6/328
(a) •Bedrock Well * 103D (Depth to gw-1£3m; distance from slag pile<50m).
.Shallow Wells » MW-4 (depth<2m; distance-100m); MW-3 (depthOm; distance-100m); 104 (depth-1m; distance- 100m);
and 105 (depth-1.7m; diatanee<200m); Background (referenced by ASARCO) - 101 (depth-0.76m; distance-244m); and
102 (depth-1.2m; distance-732m).
•Surface Water Station - 303 (Slag Pile Seep); Background • Scroggins Branch (referenced by ASARCO) - 300 (distance
from slag pil«-244m) and 301 (distance-152m).
(b) •Samples collected between 8/84 and 3/86.
(c) *First value is number of samples exceeding MCL Second value is Maximum Exeeedance Factor, derived by dividing highest
concentration detected by the MCL (e.g., a concentration of 0.12 mg/L lead exceeds the MCL of 0.05 mg/L by a factor of 2.4).
-------
10-22 Chapter 10: Primary Lead Processing
In October 1985, the Missouri Department of Natural Resources (MODNR) stated, based on the data
reviewed up to that time, that "[ejither there is a very significant nonpoint source of cadmium or there are
significant unreported discharges from ASARCO or there are both."24
In May 1987, EPA conducted a Potential Hazardous Waste Site investigation, and expressed concern
that "surface water run-off from slag piles could be contaminating the streams surrounding the lead smelter
with heavy metals."25 In 1988, under a Settlement Agreement with the MODNR, ASARCO constructed a
collection and treatment system for stormwater run-off from the facility, including the slag area.
Doe Run, Boss, Missouri
Doe Run's Buick primary smelter facility, like ASARCO's Glover facility, is situated within Missouri's
"Old Lead Belt." The facility, which began operating in 1968, was originally owned by the Amax Lead
Company and is also known as the AMAX Homestake Smelter. The 101 hectare (250-acre) plant is located
near the towns of Boss and Bixby, Missouri, in Iron County.
The site is located on a ridge separating the watersheds of the Left Fork of Neals Creek (to the south)
from that of Crooked Creek (to the north.) This area has been identified as a recharge area for the underlying
aquifer. There are private drinking water wells within a 1.6 km radius of the facility. The water table occurs
at 44.2 m (145 feet) below the land surface in both the wet and dry seasons. A perched water table also exists
at five feet below the land surface. Crooked Creek receives wastewater discharges from smelting operations,
while Strother Creek receives discharges from the mine and mill The mean annual precipitation is about 1.2
meters (46 inches).26
The slag disposal area consists of a fiat-topped "bench" along the eastern side of the head of a small
valley that is underlain by clay-based residuum. The slag is piped as a slurry to the slag disposal area where
it is dewatered, then trucked to the on-site sinter plant for reuse as sinter, or disposed in the slag disposal
area.27 A total of about 480,000 tons of slag have been placed in the slag disposal area over nearly 20 years
of primary smelter operation. The piled slag covers about 20,000 square meters (5 acres) at its base with a
thickness of 6.1 to 16.8 meters (20 to 55 feet).28 The slag pile is generally unvegetated.
In 1984 EPA Region VII performed a Potential Hazardous \Vaste Site Preliminary Assessment. The
inspector found that "surface impoundments and slag piles containing heavy metals could possibly contaminate
ground and surface water." The inspector also listed blowing dust from the slag pile under "Hazardous
Conditions and Incidents."29
Doe Run began a comprehensive investigation of the primary smelter slag disposal area in 1984. Soil
boring analyses revealed that some residuum samples from beneath the slag contained elevated concentrations
of lead, zinc, and cadmium. Exhibit 10-10 shows analyses of boring samples typical for uncontaminated
residuum, contaminated residuum, and the slag itself. These data show that uncontaminated residuum might
contain up to 10 mg/kg lead. The slag itself may contain 3,800 mg/kg, while the residuum contaminated from
slag leachate may contain 2,400 mg/kg lead. Similar comparisons can be made for zinc and cadmium, and
possibly copper.30
24 Missouri Department of Natural Resources, 1985. Memo from J. Ford to R. Hentges, Re Discharges from the ASARCO smelter
at Glover.
25 U.S. EPA Region VII, 1987. Potential Hazardous Waste Site, Site Identification, for .ASARCO lead smelter in Glover, Missouri.
tt Doe Run Company, 1969. Buick Resource Recovery Facility RCRA Part B Permit Application.
"Ibid.
28 Barr Engineering, 1989. Letter from D. ConneU to D. Kennedy, Region VII, Re Revised RCRA Facility Assessment Report (Copy
of Report Attached).
29 U.S. EPA Region VII, 1984. Potential Hazardous Waste Site, Preliminary Assessment, for Amax Lead Co. smelter in Boss, Missouri.
30 Doe Run Company, 1989. Buick Resource Recovery Facility RCRA Pan B Permit Application.
-------
Chapter 10: Primary Lead Processing 10-23
Exhibit 10-10
Metals Content of Slag and Residuum
Doe Run, Boss, Missouri
Sample
K1
K2
K9
K10
KB
Description
Residuum
Residuum
Residuum
Residuum
Slag Pile
Depth (ft)
16-16.5
54-54.5
43.5-44
21 -22
24 - 24.5
Concentration (nig/Kg)
Pb
5.4
10
2,400
990
3,800
Zn
16
27
380
230
6,800
Cd
0.11
0.13
7.3
2.8
14
Cu
37
41
160
28
250
Monitoring well data from 1988 show that cadmium, lead, and zinc concentrations in the ground water
below the slag disposal area exceed drinking water standards. These data, summarized in Exhibit 10-11, show
that contamination of the ground water below the slag disposal area has occurred, though it is unclear if this
contamination can be attributed to the slag pile directly or to two adjacent impoundments that contain water
from the slag storage area. Several independent laboratories analyzed subsamples of each sample to derive
a mean value. Mean cadmium levels ranged up to 0.67 mg/L (67 times the MCL); lead ranged up to 0.6 mg/L
(12 times the MCL); and one mean value for zinc contained 7.4 mg/L (1.5 times the MCL). Three wells had
consistently elevated cadmium levels: the 11 samples from well K2 averaged 0.087 mg/L; the six samples from
well K5A averaged 0.431 mg/L; and the six samples from well K8 averaged 0.021 mg/L These wells were all
located within 125m of the slag disposal area, and all appeared to be downgradient31 Background
monitoring well data were not located in the available documentation.
Midvale Slag, Midvale, Utah
Slags from both primary copper and lead smelting operations have been co-disposed at this facility.
Heavy-metal contamination of ground-water has been linked to these slag deposits. This situation is more fully
described under Damage Case Study Findings for the copper sector (Section 6.3.2).
ASARCO, El Paso, Texas
This facility contains combined deposits of lead, copper, and zinc slag. Heavy metal contamination
of water and sediments in the Rio Grande River have been linked to these slag deposits. This situation is
more fully described under Damage Case Study Findings for the copper sector (Section 6.3.2).
10.3.3 Findings Concerning the Hazards of Lead Slag
Review of available data on the slag and slag leachate constituent concentrations indicates that 12
constituents are present in concentrations that exceed the risk screening criteria used in this analysis by more
than a factor of 10: arsenic, cadmium, chromium, lead, selenium, antimony, silver, zinc, iron, cobalt,
manganese, and mercury. Of these constituents, arsenic, cadmium, lead, mercury, and selenium in lead slag
leachate were also measured using the EP leach test in concentrations that exceed EP regulatory levels.
Concentrations measured using the SPLP leachate test, however, never exceeded the EP regulatory level.
Ibid.
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10-24 Chapter 10: Primary Lead Processing
Exhibit 10-11
Summary Monitoring Well Data for the Slag Disposal Area(a)
Doe Run, Boss, Missouri
Well No.
K2
K2
K2
K2
K2
K5a
KSa
KB
KB
K8
K10
K10
K12
K13
K13
K13
K13
Depth to g.w.
(«)
42.4
42.4
42,4
42.4
42.4
24.0
24.0
10.9
61.0
81.0
138.1
138.1
95.1
136.3
138.3
136.3
136.3
Date
06/08/88
07/07/88
08/10/88
09/15/88
10/13/88
06/09/88
09/15/88
08/10/88
06/09/88
09/15/88
07/07/89
08/10/88
08/10/88
06/09/88
07/07/88
08/10/88
09/15/88
Averaged Re*uft* from 31o 4 Ube (mg/L)
Cd
(0.01 )W
0.08
0.07
0.09
0.12
0.082
0.48
O67
-
021
0.022
—
-
-
-
-
-
:
Pb
(0.05)0"
_
0.09
0.60
-
_
-
_
0.08
0.08
—
—
0.08
0.06
0.116
0.077
0.08
-
Zn
(5.00)w
_
_
_
_
_
-
7.4
_
_
_
_
_
_
_
_
_
-
Mn
(0.5)(e>
2.0
2.5
2.7
4.1
3,0
0.84
1.7
_
1.8
2.9
2.3
0.66
_
1.2
1.7
1.6
1.9
(a) By noting positions on potentiometric map, wells were all downgradient, and within 125m of slag disposal area.
(b) Primary MCL (mg/L)
(c) Secondary MCL (mg/L)
Based on an examination of the characteristics of each site and predictive modeling, the most likely
pathway for contaminants to be released into the environment is through erosion to surface water. At the
Glover, East Helena, and Boss facilities, the Agency estimated that, without any run-off controls, erosion from
lead slag piles may result in annual average concentrations of arsenic, lead, iron, manganese, and/or zinc in
nearby creeks that exceed human health and ecological protection criteria, by as much as a factor of 19.
However, run-off from the slag piles at the Glover and Boss facilities is presently collected and treated prior
to discharge. Depending on the efficiency of these control systems, surface water contamination caused by slag
pile run-off at Glover and Boss is likely to be significantly lower than predicted.
Significant releases to ground water appear less likely considering the generally low net recharge, low
permeability of the earth materials underlying the slag piles, and large depths to useable ground water at each
facility, as well as the tendency of most of the metals in lead slag to bind to soil At three facilities, the
Agency predicts that the metals from lead slag piles would be largely bound to subsurface soil and would not
reach ground water within 200 years. However, the Agency's modeling indicates that, under natural recharge
conditions, ground water within the facility boundary at Glover and East Helena could be contaminated with
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Chapter 10: Primary Lead Processing 10-25
cobalt in excess of irrigation guidelines. Also at Glover, the Agency predicts that arsenic concentrations in
ground water could cause a cancer risk of 4xlO"7, but this contamination is expected to be confined to the
facility property and is well below the MCL.
Air pathway modeling indicates that it is very unlikely for slag piles to cause harmful concentrations
of contaminants in the air at the nearest residences.
Monitoring data collected during the Agency's efforts to identify documented cases of damage confirm
the existence of high contaminant concentrations in leachate seeps and/or run-off from lead slag piles. In
particular, monitoring data show that "surface water seeps" from slag piles at the Glover and East Helena
facilities contain arsenic, lead, and/or cadmium in concentrations that exceed the primary drinking water
standards. These seeps appear to represent largely undiluted leachate and run-off, rather than ambient surface
water concentrations after contaminants have been fully mixed in the flow of nearby creeks, as analyzed by the
modeling. However, the documented presence of the seeps and their high contaminant concentrations
generally support the modeling conclusion that run-off, if not controlled, could be an important contributor
to surface water contamination. As noted above, the Glover facility now collects and treats fluids coming from
the pile prior to discharge. In addition, the East Helena facility has discontinued the practice of sprinkling
the pile with wastewater to control dust, which was believed to be the primary source of the slag pile seepage.
Information collected during the damage case research also suggests that the slag pile at the Boss
facility may be a source of surface water contamination. Site-specific modeling at this facility predicts that run-
off from the slag pile, if not controlled, could result in iron and manganese concentrations in Crooked Creek
that exceed the MCLs by a factor of 2, and lead concentrations that exceed the proposed revised MCL for lead
by a factor of 12. This creek, however, is not currently used as a source of drinking water within 24 km of the
facility, and given its low flow (16 mgd), it is uncertain if it could provide a drinking water supply in the future.
Furthermore, the slag pile is equipped with stormwater run-off controls, and the actual contaminant
concentrations in Crooked Creek are likely to be lower than predicted.
Monitoring data collected for the damage cases suggest more ground-water contamination than is
predicted by the modeling. Monitoring data for the Glover, East Helena, and Boss facilities indicate that
primary drinking water standards for lead, cadmium, and arsenic have been exceeded in ground water on the
plant property. At all three sites, lead slag is only one of several possible sources of the observed
contamination, though the slag pile appears to be the primary source of contamination of some of the wells
at the Glover facility. The Agency's modeling predicts that the slag piles at Glover and East Helena may cause
ground water contamination, but not at the levels and downgradient distances that were observed. Similarly,
the Agency predicted essentially no ground-water contamination at Boss. These differences appear to be
caused by the following factors:
• It appears likely that the contamination observed in a well approximately 100 meters
downgradient from the slag pile at Glover was caused, in part, by overland migration
of fluids from the pile. As described previously, highly concentrated "surface seeps" near
the base of the pile have been observed at this site. Prior to the installation of run-off
controls in 1988, it may have been possible for this seepage to migrate over the land or
through drainage ditches and then percolate into this shallow well (which is screened
at a depth of only 2 meters).
• The slag pile at the East Helena facility is downgradient from two process wastewater
ponds that appear to be the principal contributors to ground-water contamination. The
documented presence of contamination upgradient of the slag pile substantiates that
other release sources are likely to exist Furthermore, it is possible that some, if not
most, of the ground-water contamination potentially attributable to the slag pile was
caused by the former practice of sprinkling contaminated wastewater on the pile for the
purpose of dust control. This water added to the pile provided a much larger
contaminant load and created a much greater potential for leaching than the naturally
low precipitation and recharge considered in the modeling.
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10-26 Chapter 10: Primary Lead Processing
• The slag pile at the Boss facility is adjacent to two unlined impoundments that may be
contributing to the observed contamination. In addition, the facility is underlain by
dolomite, which is prone to form solution cavities that can allow contaminants to
migrate readily in ground water. It is possible that some of the observed ground-water
contamination at this site migrated through such cavities, which were not considered in
the modeling.
10.4 Existing Federal and State Waste Management Controls
10.4.1 Federal Regulations
Under the Clean Wfcter Act, EPA has the responsibility for setting "effluent limitations," based on
the performance capability of treatment technologies. These "technology based limitations" which provide the
basis for the minimum requirements of NPDES permits, must be established for various classes of industrial
discharges, including a number of ore processing categories.
Permits for mineral processing facilities may require compliance with effluent guidelines based on best
practicable control technology currently available (BPT) or best available technology economically achievable
(BAT). BPT effluent limitations allow no discharge from hard-lead refining slag granulation. These
limitations do not apply to stormwater point sources, such as run-off from a slag pile, or to mining and
beneficiation operations. Other processes related to slag management for which discharges are allowed
include:
Dross reverberatory slag granulation (40 CFR 421.72(d)):
Pollutant
Total Suspended Solids
Lead
Zinc
PH
Daily Maximum
236,000 mg/kkQ
9,499 mg/kkg
8,405 mg/kkg
7.5 - 10
Average Maximum Monthly
11 2,300 mg/kkg
4,318 mg/kkg
3,512 mg/kkg
Blast furnace slag granulation (40 CFR 421.72(c)):
Pollutant
Total Suspended Solids
Lead
Zinc
pH
DrtyMulmum
153,000 mg/kkg
6,1 55 mg/kkg
5,446 mg/kkg
7.5 - 10
Average Maximum Monthly
72,400 mg/kkg
2,798 mg/kkg
2£76 mg/kkg
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Chapter 10: Primary Lead Processing 10-27
BAT limits for existing sources for processes related to slag management include:
Dross reverberatory slag granulation (40 CFR 421.73(d)):
Pollutant
Lead
Zinc
Dally Maximum
1,612mg/kkg
5,872 mg/kkg
Average Maximum Monthly
784.4 mg/kkg
2,418 mg/kkg
No discharges are allowed under BAT from blast furnace slag granulation or hard lead refining slag
granulation. No discharges of slag waters are allowed from new sources (40 CFR 421.73(c), 421.74(c) and (d)).
EPA has, under the Clean Air Act (40 CFR 60.180), established the national primary and secondary
ambient air quality standards (NESHAP) for lead at 1.5 /jg/dscm.
10.4.2 State Regulation
The five primary lead processing facilities that generate lead slag are located in Missouri (three
facilities), Montana (one facility), and Nebraska (one facility). Only Missouri and Montana were selected for
detailed regulatory review for the purposes of this report (see Chapter 2 for a discussion of the methodology
used to select states for detailed regulatory study).
All three states with facilities generating lead slag exclude mineral processing wastes from their
hazardous waste regulations. Historically, Missouri also has not addressed lead slag under its solid waste
regulations. Montana classifies lead slag as solid waste, but exempts solid wastes managed on-site, such as the
slag generated at the East Helena facility, from regulatory requirements. Although not studied in detail, a
brief review of Nebraska's regulations suggests that this state does not address lead slag as a solid waste.
Missouri does currently require owners/operators of lead facilities to obtain NPDES permits for storm water
discharges, and thus establish run-on/run-off controls. According to state officials in Montana, run-off from
lead slag piles does not require a NPDES permit and is not addressed otherwise. Finally, although mineral
processing facilities in both states must obtain air permits in order to operate, there are no specific regulations
addressing fugitive dust suppression for lead slag in either state.
In contrast to this current lack of formal control, Missouri recently passed a Metallic Minerals Waste
Management Act, which will apply to generators of lead slag. This act requires that facility owners/operators
submit permit applications for active existing and new operations. Each permit application must include
operating information, a detailed closure plan, an inspection and maintenance plan, and provisions for
financial assurance. Nonetheless, because the state has not yet promulgated regulations to implement the Act,
and the first permitting cycle has not yet been completed, the extent and nature of environmental controls that
will ultimately be imposed on the slag management activities of the state's three facilities cannot be predicted.
In summary, neither of the two study states with primary lead processing facilities have imposed
environmental controls, under either hazardous or solid waste regulatory authorities, on the lead slag
management activities conducted at those facilities in the past. Moreover, although Missouri recently enacted
new minerals waste legislation and appears to be preparing to actively address lead slag, the state has not yet
promulgated regulations to implement that legislation. The nature and extent of environmental control
requirements ultimately placed on lead slag wastes, therefore, cannot be predicted with confidence at this time.
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10-28 Chapter 10: Primary Lead Processing
10.5 Waste Management Alternatives and Potential Utilization
10.5.1 Waste Management Alternatives
Waste management alternatives, as discussed here, include both waste disposal (e.g., in landfills and
waste piles) alternatives and methods of minimizing the amount of waste generated. Waste minimization
alternatives include any source reduction or recycling that results in either the reduction of total volume or
toxicity of the waste. Source reduction is a reduction of waste generation at the source, usually within a
process. Source reduction can include: process modifications, feedstock (raw material) substitution,
housekeeping and management practices, and increases in efficiency of machinery and equipment. Source
reduction includes any activity that reduces the amount of waste that exits a process. Recycling refers to the
use or reuse of a waste as an effective substitute for a commercial product, or as an ingredient or feedstock
in an industrial process.
Opportunities for waste minimization through raw materials substitutions are limited in general by
the characteristics of the ores that are processed. Selection of source ores and improved beneficiation
techniques, however, may lead to reduced slag volumes in some cases . Other source reduction opportunities
may involve process modifications that increase the efficiency of metal recovery during the smelting operation.
Recycling blast furnace slag to the sinter plant, and recovering lead and zinc from the slag by slag
fuming, are the primary waste minimization practices currently employed in the primary lead processing sector.
Recycling Lead Slag
Description
The purpose of recycling blast furnace slag to the sinter plant is to recover metals that would
otherwise remain in the slag, and to control the concentration of lead in the materials being fed to the sinter
plant When recycled, the slag is blended with the other sinter plant input materials (e.g., ore concentrates,
flue dust, and fluxes). The resulting mixture is pelletized and roasted in the sinter plant At facilities which
practice slag recycling, approximately 36 percent of the sinter plant's feed is made up of slag.32
Current and Potent/a/ Use
Of the five primary lead processing facilities in the U.S., the three facilities in Missouri recycle as
much as 73 percent of their slag to the sinter plant33 The galena ore in Missouri is rich in lead content, so
that the facilities there may need to recycle their slag to the sinter plant, even if it means retrieving slag from
the waste pile.34
The ASARCO facilities in East Helena, Montana and Omaha, Nebraska do not recycle their lead
slag.35 Presumably the East Helena facility does not recycle its slag because the lead concentrations of the
ore concentrate they process are lower than in the Missouri ore concentrate (74-76 weight percent).36
ASARCO's facility in Omaha, Nebraska does not have the option of recycling its slag on-site since it only
** PEDCo Environmental Inc. 1980. Industrial Process Profiles for Environmental Use. Chapter 27: Primary Lead Industry. EPA-
600/2-80-168, Environmental Protection Technology Series, Industrial Environmental Research Laboratory, ORD, U.S. Environmental
Protection Agency, July, p. 25.
33 Doe Run, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Processing Facilities," U.S. EPA, 1989.
» Ibid.
35 EPA in house information. Jury 1987.
34 PEDCo Environmental, Inc., oj>. tit. pp. 17-18.
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Chapter 10: Primary Lead Processing 10-29
refines lead bullion and does not have a sinter plant or blast furnace. Apparently it is not economically
feasible to transport the slag to another facility for recycling.
Therefore, of the two facilities that do not recycle their slag, only East Helena has the alternative
available, and it is uncertain what impact recycling would have on the volume or composition of slag being
generated. The amount of slag being recycled at the three Missouri facilities could perhaps be increased by
implementing process modifications, but it is uncertain whether this would significantly reduce the quantity
of slag ultimately disposed.
Factors Relevant to Regulatory Status
While the specific effects of slag recycling on slag volume and composition are uncertain, data on the
composition of slag from different ores and refining processes37*38'39 suggest that recycling will not
reduce waste volume or lead content by more than a few percent. Therefore, the use of recycling is unlikely
to change the way in which lead slag should be regulated.
Feasibility
The recycling of slag at ASARCO's East Helena facility is almost certainly technically feasible, as is
the possibility of increasing the amount of slag being recycled at the three Missouri facilities, but it is not
certain that more recycling would be profitable. The primary factor influencing a facility's decision to recycle
smelter slag is the concentration of metal in the slag. Slags with low lead content are likely to be disposed
of instead of recycled due to the increased costs associated with recycling and the minimal benefits (e.g.. small
quantities of lead recovered).
Slag Fuming
Description
The primary purpose of slag fuming is to recover zinc oxides, created through reoxidation of the
metals in the bottom portion of the blast furnace, which would otherwise remain in the slag. Lead recovery
by slag fuming is also possible to some extent Slag fuming is done by charging the molten lead slag to a fume
furnace and injecting a stream of air and pulverized coal to maintain the necessary temperature and a reducing
environment. The zinc and lead are then reoxidized by a stream of secondary air above the surface of the slag,
and collected as paniculate matter from the furnace gases.40
The waste streams from slag fuming consist of the exhaust gas, which contains the zinc and lead being
recovered and the volatile components of the blast furnace slag,41 the remaining slag, and water used to
quench and granulate the slag. The exhaust gas is controlled/treated by first cooling it and then sending it to
baghouses where the particles are removed and the volatile components are condensed. The remaining slag
is believed to be physically and chemically similar to unfumed slag, being made up of compounds of aluminum,
calcium, iron, magnesium, silicon, and other elements.42 (The main difference between fumed and unfumed
slag is the reduced concentrations of lead, zinc, and volatile components in the fumed slag.) The fumed slag
37 Ibid., p. 37.
38 Higgins, Leo M. Ill, William H. Bauer, and Dodd S. Can, 1960. "Utilization of Lead and Zinc Slags in Ceramic Construction
Products," Conservation & Recycling. VoL 3, p. 376.
39 Collins, RJ. and RJt Miller, 1976. Availability of Mining Wastes and Their Potential for Use as Highway Material - Volume I:
Classification and Technical and Environmental Analysis. FHWA-RD-76-106, prepared for Federal Highway Administration, May, p. 119.
40 PEDCo Environmental, Inc., oj>. at. p. 42.
41 Ibid.
42 Ibid.
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10-30 Chapter 10: Primary Lead Processing
is disposed of by cooling it with either air or water (which granulates it), and sending the cooled slag to a
waste pile or tailings pond. When water is used to quench the fumed slag, the concentrations of sulfate have
been observed to increase by 70 ppm, lead by 0.18 ppm, and zinc by 0.38 ppm,43 which are comparable to
the changes seen in unfumed slag quench water. W&ter used to quench and granulate the slag may undergo
some form of treatment before being reused or discharged, but the portion used to slurry the granulated slag
if often disposed with the slag.
Current and Potential Use
Of the four active U.S. facilities with smelting operations, none are currently using slag fuming to
recover zinc oxide or lead from their blast furnace slag. At present, only the ASARCO facility in East Helena,
Montana is believed to have slag fuming equipment installed, but it has not fumed slag since the early 1980's.
The three facilities in Missouri also used to run slag fuming operations but no longer do so, and have removed
their fuming ovens. EPA believes that the reason these facilities no longer have active fuming operations is
that electric arc furnace dust from steel production and zinc slab are sources of purer, less expensive zinc
oxide. If the price of zinc oxide were to rise, it is possible that ASARCO's East Helena facility would resume
slag fuming. The lead facilities in Missouri might also resume slag fuming, but they would require more
incentive than the East Helena facility, because they would have to install fuming equipment.
Factors Relevant to Regulatory Status
Lead and zinc concentrations in lead slag can range from 0.1 to 3.5 and from 2.0 to 17.5 percent by
weight, respectively.44'45 Therefore, even with complete lead and zinc recovery, slag fuming could reduce
the amount of slag generated by a maximum of 21 percent by weight, and perhaps by as little as 2.1 percent
by weight. Assuming an annual slag production of 540,000 metric tons,46-47 that all of the slag is fumed,
and that all of the lead and zinc are recovered from the slag, the amount of slag would be reduced by 11340-
113,400 metric tons per year.
EPA does not believe that the use of slag fuming is likely to result in the need for regulations more
stringent than would be applied to unfumed slag. In fact, fumed slag could potentially be of less concern than
unfumed slag due to the lower toxic metal content
Feasibility
While slag fuming may not be technically feasible at the ASARCO facility in Omaha, Nebraska, slag
fuming has seen extensive use in the past at the facilities in Montana and Missouri. Therefore, its technical
feasibility has been demonstrated. Economic feasibility hinges on the price of the zinc oxide produced and/or
the benefits that might be derived from lowering the slag's lead and zinc concentrations.
Disposal Alternatives
Of the five lead processors, only the facility in Omaha, Nebraska sends its slag off-site for disposal.
While it is conceivable that some, or even all, of the other lead processors could do so, the cost of transporting
large volumes of lead slag, and the rising cost of commercial landfill capacity make it unlikely that lead
43 Ibii, p. 43.
44 Md,p.37.
45 Collins, RJ. and R.H. Miller, og. at. p. 119.
44 This figure is based on the four smelting facil
i of lead.
47 PEDCo Environmental, Inc., 1980, og. at. p. 6.
44 This figure is based on the four smelting facilities operating at their maximum capacity and generating one ton of slag for every
ton of lead.
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Chapter 10: Primary Lead Processing 10-31
processors will utilize off-site disposal capacity if on-site capacity is available and the regulations do not
change.
10.5.2 Utilization
Utilization as a Construction Aggregate in Asphalt
Description
Lead slag has been used as an aggregate in asphalt used to surface roads. If the slag is water cooled
(i.e., granulated) it may be usable with little or no crushing and screening. If, however, the slag is air-cooled,
it will almost certainly require processing to produce the desired particle sizes. Once the slag has been sized
it can then be mixed with the asphalt mixture.
Current and Potential Use
48
Lead slag was field tested as an aggregate in asphalt paving during the mid 1970s. Lead slag has
been shown to have desirable anti-skid and wear resistant properties,49 and was used as an asphalt aggregate
in eastern Missouri for a number of years in the 1970s. The Missouri State Highway Commission also made
limited use of lead slag in asphalt mixtures used to patch and seal roads in the winter. In Idaho, the asphalt
used to pave Interstate Route 90 utilized granulated lead slag as an aggregate.50 EPA, however, has found
no information indicating that lead slag is currently being used as an aggregate in asphalt road paving.
The potential of lead slag as a construction aggregate depends at least partly on its ability to compete
successfully in the market place with the other sources of aggregates. Two of these factors are discussed below,
and a third (competitive pricing) is discussed in the section on Feasibility.
Access to Markets
It is important that the waste be located as close as possible to its market in order to keep
transportation costs low. Waste located within 80 and 160 km (50 to 100) miles of major metropolitan areas
or aggregate shortage areas are considered as being near potential markets.51 The three facilities in Missouri
are all located within 160 km (100 miles) of both St. Louis and Springfield. The facility in East Helena,
Montana is located within 160 km (100 miles) of Butte and Helena, and within 320 km (200 miles) of an area
in central Montana with an aggregate shortage. The ASARCO plant in Omaha, Nebraska is located within
the metropolitan area of Omaha, and is within 160 km (100 miles) of southwestern Iowa, which has a shortage
of aggregate. Therefore, all of the facilities have potential markets for use of their slag as an aggregate
material.
Factors Relevant to Regulatory Status
The use of lead slag in asphalt is unlikely to alter the chemical composition of the slag. EPA believes
that the physical entrainment of the slag in the asphalt will reduce the leaching of hazardous constituents from
the slag as compared to disposal in an uncovered waste pile. However, to the extent that hazardous
constituents do leach from slag used as aggregate in asphalt, the releases would be less controllable than those
from a more localized source such as a waste pile.
48 Collins, RJ. and R.H. Miller, og. at. pp. 200 ud 210.
* Ibid., p. 167.
50 Ibid., p. 166.
51 Collins, RJ. and R.H. Miller, ojj. at. p. 239.
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10-32 Chapter 10: Primary Lead Processing
Any slag particles that are too small to be used as an aggregate will still have to be disposed, unless
they can be utilized in some other way (e.g., as a substitute for portland cement, as is discussed later). If
disposed, there will be a greater potential for leaching or transport as dust due to the relatively small particle
size.
Feasibility
The perception that lead slag might be harmful has entirely stopped its utilization as a component
of asphalt for road paving. The use of granulated lead slag as an aggregate in asphalt in eastern Missouri was
discontinued in the mid-1970s because the Missouri Department of Natural Resources suspected that there
were significant amounts of lead in the slag, and that lead might escape into the environment through leaching.
The Missouri lead producers, in order to avoid negative publicity, withdrew their slag from the market and
chose instead to dispose of it as they had in the past52
In the event that the relevant agencies of State government were to reverse their position on this
issue, the economic viability of lead slag as an aggregate would depend on the selling price of the slag, the cost
of retrieving the slag from the disposal area, the amount of crushing and screening needed to size the slag,
and the distance the slag would have to be transported prior to use.
10.5.3 Miscellaneous Utilization
There are a number of ways to utilize lead slag which are mentioned in the literature, but for which
there is little information beyond the fact that a particular practice may have occurred. Below, EPA discusses
and comments on each potential means of waste utilization to the extent permitted by the information
available.
Substitute for Portland Cement in Construction Blocks
It has been shown that finely ground lead slag can be used to replace up to 25 percent of the portland
cement in steam cured blocks without a significant loss in block strength.53 The blocks are manufactured
from a mixture of sand, portland cement, ground slag, and water, which is pressed into shape and then steam
cured for 10 hours at 90 degrees centigrade. Whether the slag in such blocks would pose any risk to human
health or the environment is not known; moreover, it is unclear whether the economics of utilization would
be favorable, since the slag would require extensive grinding before use.
Frost Barrier and Buried Pipeline Bedding Material
In Idaho, granulated slag from the Bunker Hill Company smelter in Kellogg, Idaho (now closed), was
used as a frost barrier under slabs of concrete and asphalt, as well as a bedding material for buried
pipelines.54 The literature does not report how much lead slag has been used for these purposes, or how
it performed.
Using lead slag as a pipeline bedding or frost barrier material will not change the chemical or physical
characteristics of the slag, although it may have some effect on the ability of the slag's hazardous constituents
(e.g., lead and cadmium) to leach and contaminate ground and/or surface waters. For instance, when the slag
is used as a frost barrier under cement or asphalt slabs, the amount and rate of leaching should be reduced
significantly with respect to current slag waste management practices that allow water to run over the slag.
52 Ibid., p. 167.
53 Higgins, Leo M. Ill, William H. Bauer, and Dodd S. Carr, og. at. pp. 375-382.
M Collins, RJ. and R.H. Miller, O£. tit., p. 166.
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Chapter 10: Primary Lead Processing 10-33
When slag is used as bedding material for pipelines, the rate of leaching will depend on environmental settings,
and could vary considerably.
Air-Blasting Abrasive
Lead slag has been used as an air-blasting abrasive. Slag from a closed smelter site (currently owned
by the Valley Materials Corporation) in Midvale, Utah is being processed and sold as air-blasting abrasive by
Blackhawk Slag Products in Utah, Colorado, and Nevada. The slag is processed into four different size grades
and sold for such uses as the removal of paint from concrete and steel structures, as well as the removal of
road paint stripes.55
It is not known how much lead slag is currently being sold as air-blasting abrasive, or the scope of
the potential market for this product. No information has been found to indicate that lead slag at other sites
in the United States could not be utilized as air-blasting grit.
Virtually all of the slag that is used as input in the production of the abrasive is incorporated in the
product, so disposal of the residues poses no problem. The primary concerns with respect to human health
and the environment arise from the potential for inhaling the grit when it is used, and the leaching of heavy
metals from the grit after it has been used. Blackhawk does not believe that the potential dangers from
inhalation of the grit pose a significant threat to human health if people without protective equipment are
kept away when it is being used.56 It is not known how much of the grit might be picked up by the wind
and inhaled by people. With respect to leaching, results from EP toricity test extract analyses of the air-
blasting grit were all well below the regulatory standards.57
Railroad Ballast
Valley Materials Corporation in Midvale, Utah also is processing (sizing) slag for use as a railroad
ballast. It is not known how much lead slag is currently being sold for use as railroad ballast, or the scope
of the potential market for this product No information has been found to indicate that lead slag at other
sites in the United States could not be utilized in this way.
The slag at the Midvale site has been tested for EP Tbricity and found to be well below the regulatory
standards.58
10.6 Cost and Economic Impacts
Section 8002(p) of RCRA directs EPA to examine the costs of alternative practices for the
management of the special wastes considered in this report EPA has responded to this requirement by
evaluating the operational changes that would be implied by compliance with three different regulatory
scenarios, as described in Chapter 2. In reviewing and evaluating the Agency's estimates of the cost and
economic impacts associated with these changes, it is important to remember what the regulatory scenarios
imply, and what assumptions have been made in conducting the analysis.
The focus of the Subtitle C compliance scenario is on the costs of constructing and operating
hazardous waste land disposal units. Other important aspects of the Subtitle C system (e.g., corrective action,
prospective land disposal restrictions) have not been explicitly factored into the cost analysis. Therefore,
differences between the costs estimated for Subtitle C compliance and those under other scenarios (particularly
Subtitle C-Minus) are less than they might be under an alternative set of conditions (e.g., if land disposal
55 Earthfn Engineering, Inc., 1986. Leaching Potential of Slag and Slag-Based Air-Blasting Abrasives. June.
56 Private communication with Mr. Bob Soehnlen, Vice President, Blackhawk Slag Products, Midvale, Utah, April 18, 1990.
57 Earthfax Engineering, Inc., oj>. tit.
Ibid.
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10-34 Chapter 10: Primary Lead Processing
restriction had been promulgated for "newly identified" hazardous wastes). The Subtitle C-Minus scenario
represents, as discussed above in Chapter 2, the minimum requirements that would apply to any of the special
wastes that are ultimately regulated as hazardous wastes; this scenario does not reflect any actual
determinations or preliminary judgments concerning the specific requirements that would apply to any such
wastes. Further, the Subtitle D-Plus scenario represents one of many possible approaches to a Subtitle D-Plus
program for special mineral processing wastes, and has been included in this report only for illustrative
purposes. The cost estimates provided below for the three scenarios considered in this report must be
interpreted accordingly.
In accordance with the spirit of RCRA §8002(p), EPA has focused its analysis on impacts on the firms
and facilities generating the special wastes, rather than on net impacts to society in the aggregate. Therefore,
the cost analysis has been conducted on an after-tax basis, using a discount rate based on a previously
developed estimate of the weighted-average cost of capital to U.S. industrial firms (9.49 percent), as discussed
in Chapter 2. Waste generation rate estimates (which are directly proportional to costs) for the period of
analysis (the present through 1995) have been developed in consultation with the U.S. Bureau of Mines.
In this section, EPA first outlines the way in which it has identified and evaluated the waste
management practices that would be employed by primary lead producers under different regulatory scenarios.
Next, the Agency discussed the cost implications of requiring these changes to existing waste management
practices. The last part of this section predicts and discusses the ultimate impacts of the increased waste
management costs faced by the affected lead facilities.
10.6.1 Regulatory Scenarios and Required Management Practices
Based upon the information presented earlier in this chapter, EPA believes that lead slag poses a
relatively high risk, and is likely to exhibit the hazardous waste characteristic of EP toxicity. Accordingly, the
Agency has estimated the costs associated with regulating lead slag under RCRA Subtitle C, as well as with
two somewhat less stringent regulatory scenarios, referred to here as 'Subtitle C-Minus* and "Subtitle D-Plus,"
as previously introduced in Chapter 2, and as described in specific detail below.
In the absence of actual facility-specific sampling and analysis data demonstrating otherwise, EPA has
adopted a conservative approach in conducting its cost analysis, and has assumed that lead slag would exhibit
EP toxicity at all five lead producing facilities.
Subtitle C
Under Subtitle C standards, generators of hazardous waste that is managed on-site must meet the
standards codified at 40 CFR Parts 264 and 265 for hazardous waste treatment, storage, and disposal facilities.
Because lead slag is a solid, non-combustible material, and because under full Subtitle C regulation, hazardous
wastes cannot be permanently disposed of in waste piles, EPA has assumed in this analysis that the ultimate
disposition of lead slag would be in Subtitle C landfills. Because, however, current practice at all five primary
lead facilities is storage and/or disposal of slag in waste piles, the Agency has assumed that the facilities would
also construct a temporary storage waste pile (with capacity of one week's waste generation) that would enable
the operators to send the lead slag to either on-site or off-site disposal efficiently. Given the relatively large
quantities of material generated at four of the five plants (all smelters), EPA has assumed that each of these
four plants would, as applicable, continue to recycle the same quantity of slag as it does currently, and would
dispose of the remainder in a landfill. To accommodate the portion disposed, EPA believes that, because of
cost considerations, each facility operator would construct one on-site landfill that meets the minimum
technology standards specified at 40 CFR 264, rather than ship the material off-site to a commercial hazardous
waste landfill or build multiple landfills. The fifth facility (ASARCO-Omaha) currently ships its slag off-site
for disposal; EPA assumes that this plant has disposal capacity restraints and is, therefore, likely to continue
this practice. The facility would, however, have to send the slag to a commercial Subtitle C hazardous waste
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Chapter 10: Primary Lead Processing 10-35
landfill rather than a commercial or municipal solid waste landfill (at a significant increase in waste
management complexity and cost) under this scenario.
Subfft/e C-M/nus
A primary difference between full Subtitle C and Subtitle C-Minus is the facility-specific application
of requirements based on potential risk from the hazardous special waste. Under the C-Minus scenario, as
well as the Subtitle D-Plus scenario described below, the degree of potential risk of contaminating groundwater
resources was used as a decision criterion in determining what level of protection (e.g., liner and closure cap
requirements) would be necessary to protect human health and the environment. Two facilities, those at
Herculaneum and Omaha, were determined to have a low potential to contaminate groundwater resources;
two others, those at Boss and East Helena, were determined to have a moderate groundwater contamination
potential; the fifth, at Glover, was determined to have high potential for groundwater contamination.
Under Subtitle C-minus, potentially hazardous slags can be managed in disposal wastepiles only under
low groundwater risk conditions. Therefore, under Subtitle C-rainus, both facilities with low groundwater
contamination risk would be allowed to continue to operate their present wastepiles (i.e, a disposal wastepile
at Herculaneum and storage wastepiles at Omaha), after retrofitting the units with run-on/runoff and wind
dispersal/dust suppression controls. The remaining three facilities cannot continue to operate their disposal
wastepiles and would be required to build disposal landfills. The units are assumed to require at least a three
foot liner of clay protected by a fill layer, in the case of the Glover facility with its high potential for
groundwater contamination, a composite liner (i.e., clay with a synthetic liner and a protective fill layer) and
leachate collection system are assumed to be required. All four faculties that dispose on-site (i.e., excluding
the Omaha refinery) are required to perform groundwater monitoring. In addition, the disposal units must
undergo formal closure, including a cap of crushed stone or topsoil and grass, and post-closure care must be
performed (e.g., leachate collection and treatment, cap and nin-on/nm-off control maintenance, and continued
groundwater monitoring) for a period of 30 years.
Subtitle D-Plus
As under both Subtitle C scenarios, facility operators would, under the Subtitle D-Plus scenario, be
required to ensure that hazardous contaminants do not escape into the environment. Like the Subtitle C-
Minus scenario, facility-specific requirements are applied to allow the level of protection to increase as the
potential risk to groundwater increases. Under this scenario, unlike the Subtitle C-Minus scenario, all
facilities, regardless of their risk potential for groundwater contamination, are assumed to be allowed to
continue to operate disposal wastepiles. Disposal wastepiles under high and moderate groundwater
contamination risk potentials must, however, be adequately lined (e.g., in situ clay is not considered adequate).
As none of the three lead facilities determined to have high or moderate risk potential currently conform to
this requirement, all three would rebuild disposal units, operating either disposal landfills or wastepiles,
depending on the relative cost The least cost alternative at the East Helena facility is expected to be the
disposal landfill, while the disposal wastepile is the least cost alternative at the Glover and Boss facilities. The
disposal landfills are assumed to require a day liner with a protective fill layer under the moderate potential
for risk found at East Helena; the new disposal wastepiles employed at Glover and Boss are assumed to be
underlain by concrete. Groundwater monitoring is required at all three facilities in addition to run-on/run-off
and wind dispersal/dust suppression controls; these practices must be continued through the post-closure care
period.
At the Herculaneum and Omaha facilities, current slag management units are acceptable because the
potential for ground-water contamination is low. The wastepiles would, however, be retrofitted with run-
on/run-off and wind dispersal/dust suppression controls which, as under the Subtitle C-Minus scenario, would
have to be maintained through closure and the post-closure care period. Ground-water monitoring and
capping at closure is assumed to not be required for management units under Subtitle D-Plus when the
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10-36 Chapter 10: Primary Lead Processing
ground-water contamination potential is low, though wind dispersal/dust suppression controls must be
maintained.
10.6.2 Cost Impact Assessment Results
Results of the cost impact analysis for the primary lead sector are presented by facility and regulatory
scenario in Exhibit 10-12; all five facilities are assumed to incur costs under the three regulatory scenarios.
Under the Subtitle C scenario, annualized incremental regulatory compliance costs range across facilities from
just over $1.3 million to just over $5.4 million greater than baseline; the sector-wide total is $14.6 million over
baseline. For all of the five facilities in the sector, Subtitle C compliance would imply a significant increase
in slag management costs; costs at ASARCO's stand-alone lead refinery at Omaha (which ships its slag off-site
for disposal) would increase by a factor of almost five, while on-site disposal costs at the four plants operating
lead smelters would increase by at least 25-fold and by as much as 37-fold. Compliance-related capital
expenditures are substantial at the four primary lead facilities that conduct smelting operations. New capital
expenditures at the Boss facility would exceed $3.2 million, while new waste management units at the Glover,
Herculaneum, and East Helena facilities would require capital expenditures of $10.9 million, $14.8 million,
and $25.5 million, respectively. The majority of the prospective cost impact is attributable to the design and
construction of the very large Subtitle C landfills that would be required to manage this waste. New capital
expenditures (as well as new operating expenditures) at the Omaha refinery would be modest, because EPA
believes that this facility would continue to ship its slag off-site for disposal, and hence would not experience
the costs associated with building an on-site Subtitle C disposal unit (landfill).
Under the facility specific risk-based requirements of the Subtitle C-Minus scenario, costs of
regulatory compliance are, for the sector, about half of those of the full Subtitle C scenario. Annualized
compliance costs under this scenario range from about $0.84 to $2.9 million greater than baseline; the total
compliance cost for the sector is approximately $8.7 million over baseline. Compliance-related capital
expenditures range from about $1.5 million to more than $11 million, excepting the Omaha refinery. The costs
at the Omaha facility, with its off-site disposal needs, are virtually the same under either Subtitle C scenario
as the disposal is to an off-site RCRA hazardous waste operation in either case. For the remaining four
facilities that all conduct smelting operations, this less restrictive scenario results in a reduction of required
capital expenditures of more than 50 percent. The primary reason for the difference in waste management
cost is the fact that, while all facilities would be forced to build new environmentally protective disposal units,
relaxation of the minimum technology requirements, which changes the configuration of the landfill liner,
leachate collection/detection system, and (closure) cap, would substantially reduce the capital expenditures
needed. In addition, the Herculaneum facility would be allowed to construct a disposal waste pile rather than
a landfill, reducing new capital expenditures by a factor of seven.
Under the Subtitle D-Plus regulatory scenario, compliance-related waste management costs, about
$7.6 million over baseline, are about 88 percent of the Subtitle C-minus costs (Le., a 12 percent savings),
though the costs represent a 46 percent savings over the full Subtitle C costs. At ASARCO/Omaha, EPA
assumes that the facility will construct an adequately protective land disposal unit (landfill), rather than
continue to ship its refinery slag to a commercial disposal facility (disposal in a municipal or industrial solid
waste landfill is assumed here to not be adequately protective of the environment). The facility would achieve
a cost savings of about two percent, as compared with the Subtitle C-Minus scenario, by adopting this practice.
The ASAROO/East Helena facility, with its large volume of waste sent to disposal, would build, as the least
cost practice, a disposal landfill that is identical to the landfill required under Subtitle C-Minus; costs under
the two scenarios are therefore identical. The other three facilities, because they recycle more and dispose
less smelter slag, are assumed to build, as the least cost practice, environmentally protective disposal
wastepiles, at a cost savings ranging from 16 to 34 percent, as compared to the Subtitle C-Minus disposal
landfills; estimated annualized compliance costs for these facilities range from $0.57 to $2.0 million.
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Chapter 10: Primary Lead Processing 10-37
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10-38 Chapter 10: Primary Lead Processing
10.6.3 Financial and Economic Impact Assessment
1b evaluate the ability of affected facilities to bear these regulatory compliance costs, EPA conducted
an impact assessment consisting of three steps. First, the Agency compared the estimated costs to several
measures of the financial strength of each facility (in the form of financial impact ratios) to assess the
magnitude of the financial burden that would be imposed in the absence of changes in supply, demand, or
price. Next, in order to determine whether compliance costs could be distributed to (shared among) other
production input and product markets, EPA conducted a qualitative evaluation of the salient market factors
that affect the competitive position of domestic primary lead producers. Finally, the Agency combined the
results of the first two steps to arrive at predicted ultimate compliance-related economic impacts on the lead
industry. The methods and assumptions used to conduct this analysis are described in Chapter 2 and in a
Appendix E-4 to this document, while detailed results are presented in Appendix E-5 (appendices are
contained in Volume III).
Financial Ratio Analysis
EPA's compliance cost ratios suggest that all five primary lead operations would be potentially
affected under any regulatory scenario, though impacts on the Herculaneum facility would be modest under
the Subtitle C-Minus and D-Plus scenarios. These financial ratio results are presented in Exhibit 10-13.
Under the Subtitle C scenario, three of the operations are expected to incur highly significant impacts;
annualized compliance costs as a percentage of value added exceed twelve percent at these plants. Ratios at
the remaining two plants (Glover and Herculaneum) are more moderate (about nine and five percent,
respectively). Impacts at the East Helena smelter are particularly extreme; costs approach 50 percent of value
added and annualized capital expenditures to achieve compliance would exceed annual sustaining capital at
the facility.
Impacts under the Subtitle C-Minus scenario are generally similar to those of the full Subtitle C
scenario, though of somewhat lesser magnitude, with the exception of the Herculaneum facility. The
Herculaneum smelter/refinery is assumed to be able to continue to employ a disposal wastepile under this
scenario (because it poses only a low risk to ground water); costs, and therefore, impacts, are substantially
lower (81 percent) than under the full Subtitle C scenario. ASARCO/Omaha has nearly identical ratio results,
because off-site disposal costs are the same under the two Subtitle C scenarios.
In terms of impacts, there are no dramatic differences between the Subtitle C-Minus and Subtitle D-
Plus scenarios, though, as discussed above, compliance costs would be reduced at some facilities.
Market Factor Analysis
Genera/ Competitive Position
The U.S. lead smelting and refining facilities are among the lowest cost in the world. This stems
largely from the fact that the Missouri smelter ore sources are among the only significant primary lead supplies
in the world. The fact that the lead is not associated with significant impurities allows for the production of
a concentrate (smelter feed) with very high lead content (greater than 70 percent lead). This is far different
than most lead concentrates produced by other nations, in which lead levels range from 30 to 55 percent.
Concentrates with lower lead content require more flux and coke in the smelting process, and are therefore
more expensive to refine.
Looking strictly at smelting and refining costs, however, yields a distorted picture of the overall
economics of lead production in the United States. Most foreign primary lead facilities are operated to
produce significant quantities of co-products or by-products, meaning that a substantial share of their operating
revenues are derived from sales of refined zinc, silver, and/or other metals. The U.S. lead producers have
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Chapter 10: Primary Lead Processing 10-39
Exhibit 10-13
Significance of Regulatory Compliance Costs for
Lead Slag from Primary Processing^
Facility
Subtitle C
ASARCO - East Helena, MT
ASARCO • Glover, MO
ASARCO - Omaha, NE
Doe Run - Boss, MO
Doe Run • Herculaneum, MO
Subtitle C-Mlnus
ASARCO - East Helena, MT
ASARCO - Glover, MO
ASARCO - Omaha, NE
Doe Run - Boss, MO
Doe Run - Herculaneum, MO
Subtitle D-PliM
ASARCO - East Helena, MT
ASARCO • Glover, MO
ASARCO - Omaha, NE
Doe Run • Boss, MO
Doe Run - Herculaneum, MO
CC/VOS
23.3%
5.5%
3.7%
11.4%
3.4%
12.5%
4.8%
3.8%
8.9%
0.8%
12.5%
4.0%
3.7%
5.8%
0.6%
CC/VA
49.9%
8.8%
12.2%
18.0%
5.4%
26.7%
7.6%
12.3%
14.2%
1.3%
26.7%
6.3%
12.0%
9.2%
0.9%
IR/K
105.4%
29.5%
0.5%
35.0%
19.7%
47.0%
23.6%
0.7%
16.6%
2.8%
47.0%
20.6%
13.6%
20.6%
2.3%
CC/VOS = Compliance Costs as Percent of Safes
CC/VA - Compliance Costs as Percent of Value Added
IR/K - Annualized Capital Investment Requirements as Percent of Currert Capital Outlays
(a) Values reported in this table are based upon EPA's compliance cost estimates. The Agency believes that these values are
precise to two significant figures.
minimal by-product revenues and, accordingly, are very dependent upon lead sales for their revenues. Foreign
lead facilities may smelt at a high cost but the by-product credits result in a very low allocated lead cost per
pound. For this reason, the allocated cost of lead production at many foreign facilities is less than 20 cents
per pound, despite total metal smelting and refining costs that range from 10 to 16 cents per pound.
In contrast, smelting and refining costs for Missouri facilities are on the order of 10 - 11 cents per
pound of lead, but overall cash costs of lead metal production are in the range of 20 cents per pound. As a
result, domestic producers of lead are on the upper end of the supply curve (i.e., are less cost-competitive) as
compared to most foreign lead producers.
At 1989 price levels, current production costs (about 20 cents/lb.) are adequate to produce substantial
profits for all of the integrated domestic lead producers. If, however, lead prices (in real terms) were to fall
back to historical long-range levels, then the operating margins for domestic producers would become very
small.
Potential for Compliance Cost Pass-Through
Labor Markets. There has been a considerable reduction in employment levels in the U.S. lead
industry throughout the 1980s. In order to remain cost-competitive, reductions in unit costs of both labor and
supplies were necessary to avoid permanent closure of several smelter/refinery facilities. It is unlikely that
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10-40 Chapter 10: Primary Lead Processing
there could be substantially more reductions on the labor rate side or in staffing without affecting operational
efficiency.
Raw Material Supply Markets. Since the suppliers of lead smelting and refining industry are
primarily company-owned lead mines, there is little opportunity to reduce the price paid for lead concentrate.
Some facilities might, however, be able to reduce prices paid to independent mines for concentrates to a
limited extent. Beyond a certain price level, however, those concentrates would probably be offered for sale
on the world market.
Smelter/refineries not associated with mines would be at a disadvantage in attracting concentrates
from foreign sources; they already have high operating costs on a competitive world basis.
Higher Prices. The U.S. lead producers have some limited flexibility in raising prices due to the
1 cent to 4 cent-per-pound cost advantage that they enjoy in shipping to certain areas in the U.S., as compared
to foreign lead metal suppliers. This advantage is reflected in the fact that U.S. refined production has
recovered significantly from the market downturns of the early 1980s. Domestic primary and secondary lead
sources provide almost 90 percent of U.S. requirements. As a result, domestic lead processors may be able
to pass through compliance costs to domestic consumers to a limited extent
Evaluation of Cost/Economic Impacts
EPA expects that all five domestic primary lead operations would suffer significant cost and financial
impacts from full Subtitle C regulation of lead slag. Regulation under the Subtitle C-Minus or D-Plus
regulatory scenarios would also impose significant impacts at four of the five facilities; waste management costs
at the Herculaneum smelter/refinery would not increase as dramatically, due to the environmental
characteristics of its location. Given significant waste management cost increases and a very limited potential
for compliance cost pass-through, EPA believes that stringent regulation of lead slag as a hazardous waste
under RCRA Subtitle C could pose a serious threat to the continued viability of much of the domestic primary
lead processing industry.
Estimated compliance costs represent significant portions of the value of shipments and the value
added by lead processing operations, and presumably, would at least periodically exceed the operating margins
of the lead processors. Initial capital investment requirements exceed $8 million at two facilities under both
Subtitle C scenarios and exceed $1.5 million at all smelters under either Subtitle C scenario. EPA believes
that some of these facilities might choose not to make these capital investments, and that those that did
upgrade their waste management practices might experience difficulty in obtaining external financing.
At the largest primary processing facility, Doe Run's integrated Herculaneum operation, impacts
associated with Subtitle C-Minus or D-Plus would be much less than at the other three smelter operations,
and would probably not threaten its continued operation. Additionally, should the operators of the ASAR-
CO/Omaha refinery opt to ship their refinery slag to a smelter for recycling rather than to disposal (current
practice at the three integrated lead processing facilities), then it would not incur significant impacts if lead
slag were to be removed from the Mining Waste Exclusion. Indirect impacts to the Omaha facility would be
incurred, however, if the East Helena smelter, the refinery's primary source of unrefined lead bullion, should
curtail or suspend operations. In that event, the Omaha facility would either discontinue operations or
become a secondary producer.
Even under the relaxed waste management standards of the Subtitle C-Minus or D-Plus scenarios,
at least three primary lead processors would probably incur nighty significant cost and financial impacts.
Unless recycling or reprocessing of the slag could reduce the quantities to be disposed in waste management
units, these impacts could threaten the continued viability of these facilities, even in the absence of a decision
to remove lead slag from the Mining Waste Exclusion. The Boss facility is already on standby status and new
regulatory compliance costs would likely force Doe Run to discontinue operations (even in the absence of new
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Chapter 10: Primary Lead Processing 10-41
regulations, the U.S. Bureau of Mines estimates that the long-term capacity utilization of this facility is only
20 percent). Closure of ASARCO's East Helena or Glover facilities, on the other hand, which are expected
to operate at 80 and 100 percent of capacity, respectively, would have significant repercussions not only on
the facilities themselves, but potentially on domestic extraction and beneficiation operations supplying the
plants. A portion of the reduced smelting and refining capacity would likely be picked up by secondary
processors recycling scrap lead. Although current prices for lead are relatively high, and the domestic
producers are operating at a profit, the long-term outlook for primary lead processors is uncertain.
10.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) the potential for and documented
danger to human health and the environment; (2) the need for and desirability of additional regulation; and
(3) the costs and impacts of potential Subtitle C regulation.
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of lead slag is relatively high compared to the other mineral processing wastes
studied in this report. Numerous slag samples analyzed with the EP leach test did exceed the regulatory levels.
Lead was measured in EP leachate in excess of the EP regulatory level at all five facilities, in a total of 27 out
of 101 samples. Cadmium concentrations exceeded the regulatory level in 7 out of 99 samples (from 2 of 5
facilities tested). Arsenic, mercury, and selenium concentrations measured in EP leachate exceeded the
regulatory levels only in samples of refinery slag from the ASARCO refinery in Omaha, ME. Arsenic and
selenium exceeded the regulatory levels in roughly 27 out of 94 samples, while mercury exceeded the level in
79 out of 94 samples. None of the slag samples that were analyzed using the SPLP leach test (EPA Method
1312) contained constituents in concentrations above the EP toxicity regulatory levels. In addition to these
exceedances of the EP toxicity regulatory levels, lead slag contains 12 constituents in concentrations that
exceed the risk screening criteria used in this analysis by more than a factor of 10. All of these factors lead
EPA to conclude that lead slag, especially refinery slag, could pose a significant risk if mismanaged.
Based on an examination of existing release and exposure conditions at the five active lead facilities,
as well as predictive modeling, EPA concludes that management of lead slag at some sites could allow the
migration of contaminants into surface water and ground water in harmful concentrations. At the Glover, East
Helena, and Boss facilities, the Agency estimates that, without any run-off controls, erosion from lead slag
piles could result in annual average concentrations of arsenic, lead, iron, manganese, and/or zinc in nearby
creeks that exceed human health and ecological protection criteria.59 Although significant releases to ground
water appear less likely at most sites because of hydrogeologic conditions, the Agency's modeling indicates that
ground water within the facility boundary at Glover and East Helena could be contaminated with cobalt in
excess of irrigation guidelines. Ground water on-site at the Glover facility could also be contaminated with
arsenic, but the predicted contamination would cause a lifetime cancer risk of only 4xlO"7 if ingested and is
likely to remain within the facility boundary for more than 200 years. Air pathway modeling indicates that
it is very unlikely that slag piles could cause harmful concentrations of contaminants at the locations of
existing residences.
The documented cases of damage associated with lead slag also indicate that management of the slag
could cause surface water and ground-water contamination. By collecting data from State and EPA Regional
files and personnel, EPA identified documented cases of contamination at three of the five facilities.
59 The Glover and Boos facilities, however, presently collect and treat fluids coining from the lead slag piles prior to discharge,
making it unlikely for the predicted surface water contamination to actually occur at these sites. It is possible that the contamination
could occur in the future if the run-off control systems are not maintained after closure.
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10-42 Chapter 10: Primary Lead Processing
Monitoring data show that "surface water seeps" from slag piles at the Glover and East Helena facilities
contain arsenic, lead, and/or cadmium in concentrations that exceed drinking water standards. Although these
seeps represent largely undiluted leachate and run-off (rather than ambient surface water concentrations) and
both facilities have taken steps to reduce run-off, the documented presence of the seeps and their high
concentrations support the risk modeling conclusions that run-off, if not controlled, could be an important
contributor to surface water contamination. Information collected from the damage case research also suggests
that the slag pile at the Boss facility could cause surface water contamination, as predicted by the risk
modeling. However, the damage case data suggest more extensive ground-water contamination at the Glover,
East Helena, and Boss facilities than is predicted by the modeling, possibly due to the presence of other on-site
contaminant sources and additional factors not fully accounted for in the risk modeling.
Likelihood That Existing Risks/Impacts Will Continue in the
Absence of Subtitle C Regulation
As summarized above, current waste management practices and environmental conditions may allow
contaminant migration and exposures in the future in the absence of more stringent regulation. Although all
of the existing slag piles are located within 1,100 meters of a creek or river (three are within 100 meters of
a water body) and four of the five facilities are located in areas with high to moderate precipitation rates, only
the slag piles at the Glover and Boss facilities are equipped with storm water run-on/run-off controls. In
addition, only the slag piles at the Omaha facility are equipped with a synthetic liner (made of concrete), even
though releases to ground water from the slag piles at three other sites are considered possible based on a
review of the site conditions, risk modeling results, and damage case findings. Therefore, contaminant
migration during the operating life of most units appears possible, and these releases could persist after closure
if the units are not closed properly. Considering the intrinsic hazard of the waste, these releases could
conceivably cause ecological impacts, as well as significant human exposures if nearby ground or surface water
is used.
Because of overall market conditions, EPA believes that the prospect of additional primary lead
smelting/refining facilities commencing operation in the U.S. is unlikely. Therefore, EPA believes that it is
unlikely that new lead facilities will start up in the future having management practices and environmental
conditions different than those considered here. However, the refinery slag from the Omaha facility -- which
contains by far the greatest concentration of contaminants of the lead slag analyzed - is shipped off-site for
disposal. EPA has no information on the management controls and environmental conditions at this off-site
location, which could be conducive to releases and associated risks. Furthermore, although the slag is
presently not used off-site, it has been in the past and conceivably could be again in the future. Any off-site
uses, if not properly controlled, could also result in damages in the future.
EPA concludes that current State regulation of lead slag management practices is notably limited in
scope. The five existing facilities are located in Montana, Nebraska, and Missouri (three facilities), all of which
exclude mineral processing wastes from hazardous waste regulation. Montana classifies lead slag as solid
waste, but excludes slag generated at the East Helena facility from solid waste regulatory requirements because
the slag is managed on-site. Although not studied in detail for this report, a brief review of Nebraska
regulations suggests that this State also does not regulate lead slag as a solid waste. Historically, Missouri has
not addressed lead slag under its solid waste regulations. Missouri recently passed a Metallic Minerals Waste
Management Act, however, that will apply to generators of lead slag. Until the State drafts regulations to
implement this Act and issues permits, it is not dear how comprehensively or stringently Missouri will regulate
lead slag. Missouri does require owners/operators to obtain NPDES permits for storm water discharges, and
thus to install run-on/run-off controls. As discussed above, however, only the slag pile at the Glover facility
is currently equipped with such controls. Montana does not require storm water run-on/run-off controls for
lead slag piles, and neither Missouri nor Montana require measures to control fugitive dust emissions from
lead slag piles (though based on the risk modeling results, windblown dust from the existing slag piles does
not appear to pose a significant inhalation risk). Given these limited state controls, it is questionable if human
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Chapter 10: Primary Lead Processing 10-43
health and environmental protection will be ensured in the future in the absence of additional Federal
regulation.
Costs and Impacts of Subtitle C Regulation
EPA has evaluated the costs and associated impacts of regulating this waste as a hazardous waste
under RCRA Subtitle C. EPAs waste characterization data indicate that lead slag may exhibit the hazardous
waste characteristic of EP toxicity at all of the five active facilities. Costs of regulatory compliance under the
full Subtitle C scenario exceed Si million annually at all facilities; these costs would impose potentially
significant economic impacts on the operators of all five plants. Application of the more flexible
Subtitle C-Minus regulatory scenario would result in compliance costs that are approximately 40 percent lower.
Costs under the Subtitle C-Minus and Subtitle D-Plus scenarios are similar (or identical) at three of the five
facilities, because adequately protective waste management unit design and operating standards are essentially
the same under both scenarios, given the nature of the waste and the environmental settings in which it is
currently managed.
These costs would comprise a significant fraction of the value of shipments of and value added by
primary lead smelting/refining operations. ASARCO's East Helena smelter and Omaha refinery, and Doe
Run's Boss smelter/refinery would suffer particularly pronounced impacts; compliance costs as a percentage
of value of shipments approach or exceed ten percent at each of these plants, even under the Subtitle D-Plus
regulatory scenario. EPAs economic impact analysis suggests that although the current price of lead is
relatively high and domestic producers are operating at a profit, the long-term outlook for the domestic
primary lead industry is uncertain. Demand for production of refined lead from virgin sources has been falling
in recent years relative to production of secondary lead by recycling of lead-containing products (e.g.,
automotive batteries). Therefore, EPA believes that the operators of primary lead plants could pass through
a portion of any regulatory compliance costs that they might incur to product consumers, but that it is
improbable that prices could be raised to a level adequate to completely off-set regulatory compliance costs.
Finally, it is worthy of note that these impacts might occur even in the absence of a decision to
remove lead slag from the Mining Waste Exclusion, because adequately protective waste management
standards under a Subtitle D program may require the construction of new waste management units, implying
significant new capital expenditures.
Finally, EPA believes that incentives for recycling or utilization of lead slag would be mixed if a
change in the regulatory status of this waste were to occur. Recycling is currently the predominant
management practice that is applied to lead slag. It is possible that tighter regulatory controls on the
management of primary lead slag might serve to promote even greater recycling and on-site utilization than
has occurred in the recent past, e.g., through slag fuming for zinc oxide recovery. Utilization of lead slag in
construction and other off-site applications has been reported, but is not widely practiced at present, primarily
due to the availability of substitutes and concerns about environmental impacts arising from such use. It is
likely that removing lead slag from the Mining Waste Exclusion and thereby subjecting it to regulation as a
hazardous waste would, in practical terms, eliminate the use of this material in construction applications.
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Chapter 11
Magnesium Production
The primary magnesium processing industry, as discussed in this report, consists of one anhydrous
electrolytic magnesium-producing facility that, as of September 1989, was active and reported generating a
special waste from mineral processing: process wastewater from primary magnesium processing by the
anhydrous process. Two other primary magnesium producing facilities are operating in the U.S. One uses
electrolysis but employs, the hydrous process; the other uses a silicothermic process. Neither facility generates
a special waste from mineral processing covered under the Mining Waste Exclusion; therefore, these two
facilities, their operations, and the wastes that they generate are not addressed in this report. Information
included in this chapter is discussed in additional detail in the supporting public docket for this report.
11.1 I ndustry Overview
The primary use of magnesium metal is as an alloying element in aluminum-base alloys; these alloys
are used in the manufacture of such products as beverage cans and transportation equipment. Casting and
extrusions of magnesium-base alloys are used in transportation equipment, power tools, computers, and
sporting goods. Additional uses for magnesium metal are in the production of ferrous metal (e.g., iron and
steel desulfurization, and production of nodular iron) and non-ferrous metal (used as a reducing agent).1-2
The anhydrous electrolytic magnesium production facility is located in Rowley, Utah, and is operated
by the Magnesium Corporation of America (Magcorp). The facility initiated operations in 1972 and was
modernized in 1976 and 1984. The annual production capacity of the facility is reportedly 36,500 metric tons.
The total 1988 production of magnesium at the facility was 29,000 metric tons; therefore, the annual capacity
utilization rate was 79.4 percent3
No specific information was found regarding trends at the Utah facility, but, at 142,000 metric tons,
1988 U.S. production of primary magnesium was at its highest level since 1984. In 1989, the estimated U.S.
primary production was 150,000 metric tons. Primary producers operated at nearly full capacity by year end
1989.4 The primary magnesium industry in North America has expanded since 1988 as a new Canadian plant
has come on-line5 and as the Dow Chemical Company in Freeport, Texas has increased its production
capacity.6
Consumption of primary magnesium has increased significantly since 1986 when it fell to 70,000
metric tons from a 1985 level of 76,000 metric tons. Reported consumption of primary magnesium for 1989
was estimated to be 105,000 metric tons. While the U.S. imports some magnesium for consumption, it remains
a net exporter.7
1 Bureau of Mints, 1985. Mineral Facts and Problems. 1985 Ed.; p. 475.
1 Bureau of Mines, 1987. Minerals Yearbook. 1987 Ed.; p. 588-9.
3 Magcorp, 1989. Company Response to the "National Survey of Solid Wastes from Mineral Protesting Facilities," U.S. EPA, 1989.
4 Deborah A. Kramer, U.S. Bureau of Mines, "Magnesium Metal," Mineral Commodity Summaries. 1990 Ed., p. 10Z
5 Ibid., p. 103.
* Deborah A. Kramer, U.S. Bureau of Mines, "Magnesium," Minerals Yearbook. 1988 Ed., p. 1.
7 Kramer, og. at., p. 102.
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11-2 Chapter 11: Magnesium Production
Exhibit 11-1
Magnesium Production Using the Anhydrous Process
Impure
Anhydrous
Chlorine ,
Gas I
Molten
Magnesium
Process
Wastewoter
(Scrubber
Underflow)
Process
Wastewoter
(Scrubber
Liquor
SPECIAL WASTE
MANAGEMENT
Legend:
I 1 Production Operation
Special Waste
o
Waste Management Unit
In the anhydrous process used at Rowley, impure anhydrous magnesium chloride powder, which is
produced by beneficiation operations performed at the facility,8 is purified and then magnesium is isolated
using electrolysis, as shown in Exhibit ll-l.9'10 The first purification step is chlorination, which is necessary
because during the final beneficiation operation, spray drying, some magnesium oxide is generated that must
be convened to magnesium chloride. In this step, the impure magnesium powder is melted in an induction/arc
furnace and reacted with chlorine gas in a reaction cell to convert any magnesium oxide to the chloride salt.
Hydrochloric acid formed during this chlorination step is sent to scrubbers; the cleaned acid is reused in the
beneficiation operations (i.e., for sulfate removal). The scrubber underflow, one source of process wastewater,
is disposed in an on-site impoundment. Purification of the magnesium chloride is completed by the addition
of other reactants (e.g., ferric chloride, coke, sparge methane) to the molten salt to remove water, bromine,
8 The beneficiation steps include: concentration of salt brine solution; precipitation of potassium; treatment with calcium chloride for
partial removal of sulfates; and removal of boron by phase separation (i.e., solvent extraction) using isooctanol in a kerosene carrier. Upon
removal of sulfate and boron from the brine, water is evaporated at 600 degrees centigrade, producing an impure anhydrous magnesium
chloride powder.
9 Environmental Protection Agency, 1984. Overview of Solid Waste Generation. Management, and Chemical Characteristics: Primary
Antimony, Magnesium. Tin, and Titanium Smelting and Refinin£ Industries. Prepared by PEI Associates for U.S. EPA, Office of Solid
Waste, Washington, D.C., 1984.
10 Marks, 1978. Encyclopedia of Chemical Technology. Marks, et al., editors; Wiley Interscience, New York, NY, 1978; p. 581.
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Chapter 11: Magnesium Production 11-3
residual sulfate, and heavy metals.11 A low volume solid (not a special waste from mineral processing),
known as smut, is the only waste generated from this final purification operation.
After purification, molten magnesium chloride is separated into chlorine gas and molten magnesium
by applying direct current to the material in electrolytic cells. The purified and separated magnesium metal
is vacuumed from the surface of the electrolytic cell bath; the molten metal is then cast into shapes and alloyed
in a casting plant.12 The chlorine gas is removed, scrubbed, cooled, and reused or sold. Stack emissions of
chlorine gas arising from this process are significant (approximately one million pounds annually); in fact, the
Rowley facility is the nation's largest source of such emissions. The resulting scrubber liquor, which is the
second source of process wastewater, is also disposed in the on-site impoundment, along with non-contact
cooling water (not a special waste).
11.2 Waste Characteristics, Generation, and Current Management Practices13
Approximately 2,465,000 metric tons of process wastewater reportedly were generated by the Rowley
facility in 1988.14 This wastewater contains approximately 2.2 percent solids, consisting predominantly of
chlorides, magnesium, sulfate, sodium, calcium, and other metals in trace amounts.
As noted above, the process wastewater is disposed in an on-site impoundment. This impoundment
is 1.2 meters (4 feet) deep, has a surface area of about 160 hectares (400 acres), and a volume of nearly 2
million cubic meters. In this impoundment, referred to by the company as the NPDES waste pond, the pH
of the process wastewater is reportedly adjusted, though no reagents are added.15 Solar evaporation and
infiltration into the ground are used to reduce the wastewater quantity. There is no discharge to surface water
of wastewater from the pond, and no sludge is removed. Process water does not, however, accumulate, nor
do any significant volumes of solids settle out of the water in the pond, according to the company.
The impoundment is also used for disposal of several other aqueous wastewaters that are not special
wastes from mineral processing operations (e.g., calcium sulfate repulp liquor, calcium chloride thickener
underflow, and additional beneficiation wastewaters) and non-contact cooling waters; the latter stream was
generated at a volume of approximately 1,060,000 metric tons in 1988.16
Using available data on the composition of magnesium process wastewater, EPA evaluated whether
the wastewater exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability,
and extraction procedure (EP) toxicity. Based on available information and professional judgment, the Agency
does not believe the wastewater is reactive, ignitable, or EP toxic. In fact, all eight inorganic constituents with
EP toxicity regulatory levels, with the exception of selenium, are present in concentrations that are at least
two orders of magnitude below the regulatory level, that is, below drinking water standards; selenium was not
detected in the wastewater. Some wastewater samples, however, exhibit the characteristic of corrosivity. A
pH of approximately 1.2, which is below the lower bound coirosivity limit of 2.0, was measured in two out of
two samples of magnesium process wastewater at the Magcorp facility. The Rowley facility also reports that
the wastewater has an average pH of 1.6.
11 Marks, op.. Si-. P- 581.
12 Environmental Protection Agency, 1984. Overview of Solid Watte Generation. Management, and Chemical Characteristics: Primary
Antimony. Magnesium. Tin, and Titanium Smelting and Refining Industries. Prepared by PEI Associates for U.S. EPA, Office of Solid
Waste, Washington, D.C, 1984.
° Information provided in this section, unless otherwise noted, is from the response of Amax Magnesium Co. to EPA's "National Survey
of Solid Wastes from Mineral Processing Facilities," conducted in 1989.
14 The corresponding waste-to-product ratio (i.e., metric ton of process wastewater to metric ton of magnesium) was 85.
u In comments addressing the October 20,1968 NPRM (S3 FR 41288) (Docket No. - MWEP 00018), AMAX indicated that the
oolitic sand, calcium carbonate, provides "a neutralization media for the acidic wastewater."
16 In comments addressing the October 20, 1988 NPRM (53 FR 41288) and found in the docket (Docket No. - MWEP 00018),
AMAX indicated that non-contact cooling water is generated in quantities equalling 43 percent of the quantity of the process wastewater.
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11-4 Chapter 11: Magnesium Production
11.3 Potential and Documented Danger To Human Health and The Environment
This section addresses two of the study factors required by §8002(p) of RCRA: (1) potential daneer
(i.e., risk) to human health and the environment; and (2) documented cases in which danger to human health
or the environment has been proved. Overall conclusions about the hazards associated with magnesium
process wastewater are provided after these two study factors are discussed.
11.3.1 Risks Associated With Magnesium Process Wastewater
Any potential danger to human health and the environment from magnesium process wastewater is
a function primarily of the composition of the wastewater, the practices that are employed to manage it, and
the environmental setting of the facility where the wastewater is generated and managed. These factors are
discussed separately below.
Constituents of Potential Concern
EPA identified chemical constituents in the magnesium process wastewater that may present a hazard,
by collecting data on the composition of wastewater from the Magcorp facility in Rowley and evaluating the
intrinsic hazard of the chemical constituents present in the wastewater.
Data on Magnesium Process Wastewater Composition
EPAs characterization of magnesium process wastewater is based on data from a 1989 sampling and
analysis effort by EPAs Office of Solid W-iste (OSW). These data provide information on the concentrations
of 20 metals and sulfate in total analyses and EP and SPLP leach test analyses; the concentrations of
constituents measured in these three types of analyses are generally consistent.
Process for Identifying Constituents of Potential Concern
As discussed in detail in Section 2.2.2, the Agency evaluated the available data to determine if
magnesium process wastewater or leachate from this waste contain any chemical constituents that could pose
an intrinsic hazard, and to narrow the focus of the risk assessment. The Agency performed this evaluation
by first comparing constituent concentrations to screening criteria and then by evaluating the environmental
persistence and mobility of constituents that are present at levels above the criteria. These screening criteria
were developed using assumed scenarios that are likely to overestimate the extent to which the process
wastewater constituents are released to the environment and migrate to possible exposure points. As a result,
this process identifies and eliminates from further consideration those constituents that clearly do not pose
a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic ecosystems, and air and surface/ground-water resources (see Exhibit 2-3). Given the
conservative (i.e., overly protective) nature of these screening criteria, contaminant concentrations in excess
of the criteria should not, in isolation, be interpreted as proof of hazard. Instead, exceedances of the criteria
indicate the need to evaluate the potential hazards of the waste in greater detail.
Identified Constituents of Potential Concern
Exhibit 11-2 presents the results of the comparisons for process wastewater analyses to the screening
criteria described above. This exhibit lists all constituents for which the measured concentration exceeds a
screening criterion.
Of the 21 constituents analyzed in the process wastewater, only iron, molybdenum, copper, aluminum,
and manganese concentrations, as well as pH levels, exceed the screening criteria. Among these constituents,
iron, molybdenum, and pH exceed the screening criteria with the greatest frequency and magnitude. For
-------
Chapter 11: Magnesium Production 11-5
Exhibit 11-2
Potential Constituents of Concern In Magnesium Process Wastewater(a)
Potential
Constituent*
of Concern
Iron
Molybdenum
Copper
Aluminum
Manganese
PH
Number of Times
Constituent Perfected/
Number of Analyses for
Constituent
2/2
2/2
2/2
2/2
1/2
2/2
Screening Criterion
Resource Damage
Resource Damage
Aquatic Ecological
Aquatic Ecological
Resource Damage
Resource Damage
Number of Analyses
Exceeding Criteria/
Number of Analyses for
Constituent
2/2
2/2
1/2
1 12
1/2
2/2
Constituents listed in this table are present in the sample from the facility at a concentration that exceeds a relevant
screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3. Constituents that
were not detected in a given sample were assumed not to be present in the sample.
example, only iron and molybdenum exceed the screening criteria by a factor of 10 or more. No constituents,
however, were detected in concentrations that exceed the EP toxicity regulatory level, though the pH is low
enough for the waste to exhibit the hazardous waste characteristic of corrosivity. These concentrations indicate
the potential for different types of impacts caused by wastewater seepage:
• If the wastewater is released to ground or surface water and diluted by a factor of 10 or
less, iron, molybdenum, and manganese concentrations may be sufficiently high to
render the affected ground or surface waters unsuitable for a variety of uses (e.g., direct
human consumption, irrigation, livestock watering). The resulting pH levels could also
be corrosive.
Copper and aluminum are present in the wastewater at concentrations that, if released
to surface water and diluted by a factor of 100 or less, could exceed criteria for the
protection of aquatic life.
These exceedances, by themselves, do not prove that the wastewater poses a significant risk, but
indicate that the wastewater may present a hazard under a hypothetical set of release, transport, and exposure
conditions. lb determine the potential for this waste to cause significant impacts, EPA proceeded to the next
step of the risk assessment and analyzed the actual conditions that exist at the facility that generates and
manages the wastewater.
Release, Transport, and Exposure Potential
This analysis evaluates the baseline hazards of magnesium process wastewater as it was generated and
managed at the Magcorp facility in 1988. It does not assess the hazards of off-site use or disposal of the
wastewater because this waste is not currently used or disposed off-site, and off-site management or use is not
likely in the future. The following analysis also does not consider the risks associated with variations in waste
management practices or potentially exposed populations in the future because of a lack of data on which to
base projections of future conditions.
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11-6 Chapter 11: Magnesium Production
Ground-Water Release, Transport, and Exposure Potential
The waste composition data discussed above indicate that several constituents contained in the
magnesium process wastewater (i.e., iron, molybdenum, copper, aluminum, and manganese) are present in
concentrations above the screening criteria. However, depending on the pH of the seepage and the receiving
aquifer, some of the constituents may not be mobile in ground water. Molybdenum is the only constituent
that exceeds the screening criteria that is relatively mobile in ground water under neutral pH conditions.
While the pH of the process wastewater in the waste pond is very low (less than 2), it is expected to be
neutralized to some extent as the wastewater seeps through the oolitic sand (calcium carbonate) underlying
the pond. Nevertheless, the neutralization capacity of the oolitic sand is finite, and in time, acidic seepage
could potentially migrate to ground water. Although the ground water does not appear to be acidic at this
time, the continued seepage of the acidic wastewater could lower the pH to below 5, and iron, copper, and
manganese could also become relatively mobile in the aquifer. Aluminum is relatively immobile in ground
water under both neutral and low-pH conditions.
Ground water beneath the Magcorp facility occurs in shallow permeable strata that contain salt waters
intruding from the Great Salt Lake and in a deeper aquifer (located 60 meters below the land surface) that
is used as a source of livestock water. This deeper aquifer is also saline. The standing quantity of process
wastewater in the pond (which is more than 1 meter deep) provides sufficient hydraulic head to drive liquids
from the impoundment into the shallow ground water that underlies the facility. Releases to this shallow
ground water are not limited by engineered controls such as a liner or leachate collection system, and in fact,
infiltration into the ground is purposefully used by the facility and controlled by the State as a way to reduce
water volumes. The impoundment, however, is underlain by oolitic sand, which the facility claims neutralizes
any wastewater that leaches from the impoundment, and by in-situ clay.
Under these conditions, process wastewater slowly seeps into the shallow ground water beneath the
impoundment. The Utah Bureau of Witer Pollution Control stated in the NPDES permit for this facility that
data presented by Magcorp indicate that seepage from the impoundment has occurred, but that it "was of low
volume and did not pose a significant environmental or human health threat."18 Releases to the deep
aquifer are restricted by a fairly continuous clay confining layer, according to local researchers with the U.S.
Geological Survey. Therefore, seepage of process wastewater from the impoundment could contaminate the
ground water that is hydraulically connected to the Great Salt Lake, but is unlikely to adversely affect the 60-
meter deep aquifer that is used for livestock water.
Surface Water Release, Transport, and Exposure Potential
Magnesium process wastewater could enter surface waters by seeping through shallow ground water
that is hydraulically connected with the Great Salt Lake (as discussed above), or by direct overland run-off of
process wastewater in the event that the impoundment is overtopped or its berms fail. Direct discharges from
the impoundment to the lake are prohibited by the NPDES permit for the facility. As discussed above, iron
and molybdenum, and to a lesser extent, copper, aluminum, and manganese could pose human health or
aquatic ecological threats if discharged to typical receiving waters. The Great Salt Lake is not a typical
receiving water, however - there is no drinking water pathway for human exposure, and it is not clear whether
the biota in the Great Salt Lake are more tolerant or less tolerant, compared to most fresh-water species, to
elevated concentrations of these metals.
Overland run-off of process wastewater to the Great Salt Lake due to overflow from the
impoundment, resulting from excessive precipitation or berm failure, is limited by storm water run-on/run-off
controls at the unit, the low precipitation in the area (36 cm/year), and relatively small maximum snow
17 As a condition of the company's NPDES permit, Magcorp is required to monitor ground water quarterly and report any pH
excursions outside the range of 6.5 to 9.0. To the best of EPA's knowledge, no excursions have been reported as of this writing.
18 Utah Division of Environmental Health (DEH), Bureau of Water Pollution Control, 1989. Statement of Basis for Utah Pollutant
Discharge Elimination System Permit No. UT0000779.
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Chapter 11: Magnesium Production 11-7
accumulation (26 cm). Furthermore, inundation of the wastewater pond by waters from the Great Salt Lake
is unlikely because the pond berms have been raised (up to 10 meters) to safeguard against this possibility.19
Nevertheless, contaminants from the process wastewater could migrate to the lake by discharge of ground
vater from the shallow aquifer. Because the lake water is not used for consumptive purposes, surface water
releases pose no health threats from drinking water exposures, though recreational use of the lake could
potentially pose health threats. Aquatic life (i.e., brine shrimp) also may be adversely affected by any releases
of magnesium process wastewater to the lake.
Air Release, Transport, and Exposure Potential
Because all of the constituents of potential concern are non-volatile, magnesium process wastewater
contaminants can only be released to air in the form of wind-blown particles (dust). The physical form of the
wastewater essentially precludes any particle releases to air. In principle, dry deposits could be formed at the
edges of the pond when the process wastewater is evaporated to reduce its volume, and dust releases from
these deposits at the rim of the impoundment could occur (i.e., panicles could be blown into the air by wind).
However, the potential for significant airborne release and exposure is expected to be negligible because the
area of dry salt deposits is expected to be relatively small as long as the impoundment is active. After closure,
however, there may be dusting if the impoundment is dried and the remaining residue is not covered.
Proximity to Sensitive Environments
Other than the Great Salt Lake, which is used for recreational purposes, the Magcorp facility is not
located in or near environments that are especially vulnerable to contaminants or that have high resource
value (e.g., wetlands, endangered species habitats) that may warrant special consideration.
Risk Modeling
Based upon the evaluation of intrinsic hazard and the descriptive analysis of factors that influence risk
presented above, and upon a review of information available on documented damage cases (presented in the
next section), EPA has tentatively concluded that the potential for process wastewater from primary
magnesium production by the anhydrous process to impose significant risk to human health or the
environment if managed according to current practice is low. This conclusion is supported by low risk
estimates developed from the Agency's modeling of other mineral processing wastes that appear to pose a
greater hazard than magnesium process wastewater. Therefore, the Agency has not conducted a quantitative
risk modeling exercise for this waste. (See sections 11.3.3 and 11.7 below for further discussion.)
11.3.2 Damage Cases
State files were reviewed in an effort to document the performance of waste management practices
for process wastewater from primary magnesium processing by the anhydrous process for Magcorp's facility
in Tboele County, Utah. The file reviews were combined with interviews with State regulatory staff. EPA
found no documented environmental damages associated with process wastewater management units at this
facility. Nonetheless, as noted above, a study performed by the facility indicates that seepage from the
impoundment does occur, but the Utah Division of Environmental Health, Bureau of Water Pollution Control
has concluded that "the seepage was low volume and that it didn't pose any real human health or significant
environmental threat"20 In addition, releases from previous impoundments to the Great Salt Lake have
occurred in the past when the impoundments have been flooded by the lake due to high lake levels and storm
conditions, but the impacts of the releases have not been documented.
19 The pond currently in use was located on high terrain and constructed with large berms because impoundments used in the past
that were closer to the lake were flooded due to high lake levels and storm conditions.
20 Utah DEH, 1989, p^. at.
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11-8 Chapter 11: Magnesium Production
11.3.3 Findings Concerning the Hazards of Magnesium Process Wastewater
The available data indicate that wastewater is being released from the impoundment used for
wastewater disposal at the Rowley facility, but the potential danger to human health or the environment, if
any, is low due to the location of the impoundment and the characteristics of the wastewater. Specifically,
releases to the deep, useable aquifer are restricted by a fairly continuous clay confining layer. Only a few
contaminants exceeded the screening criteria and releases from the impoundment to the Great Salt Lake via
ground water or overland flow are unlikely to result in harmful concentrations in the Lake. In addition, the
pH of the seepage is being monitored under the conditions of a State permit (see below) that also requires
seepage to be prevented if the required monitoring indicates the pH is outside of the acceptable range (6.5
to 9).
Although the wastewater is corrosive, the low concentrations of toxic constituents, the evaluation of
the release, transport, and exposure pathways, and the absence of any documented cases of danger to human
health or the environment, lead EPA to tentatively conclude that the hazard posed by process wastewater from
primary magnesium production by the anhydrous process as currently managed is relatively low. As a result,
only limited discussions of alternative management practices, utilization, and costs and impacts are provided
below. The discussion of costs includes the potential costs of regulation under Subtitle C of RCRA because
the waste does exhibit the hazardous waste characteristic of corrosivity.
11.4 Existing Federal and State Waste Management Controls
11.4.1 Federal Regulation
Under the Clean Tteter Act, EPA has the responsibility for setting "effluent limitations," based on
the performance capability of treatment technologies. These "technology based limitations," which provide the
basis for minimum requirements of NPDES permits, must be established for various classes of industrial
discharges, including a number of ore processing categories. _
Permits for mineral processing facilities may require compliance with effluent guidelines based on best
practicable control technology currently available (BPT) or best available technology economically achievable
(BAT). BPT and BAT requirements for magnesium production specify that there shall be no discharge of
process wastewater pollutants to navigable waters (40 CFR 436.120).
EPA is unaware of any other federal management control or pollutant release requirements that apply
specifically to this wastewater stream.
11.4.2 State Regulation
The single primary magnesium processing facility currently active in the United States and addressed
by this report is located in Rowley, Utah. The State of Utah excludes the process wastewater generated by
this facility from both hazardous and solid waste regulation. Utah does have an approved NPDES program,
however, and requires that the Rowley facility maintain a no discharge permit for its process wastewater
surface impoundment. Under the terms of this permit, the facility owner/operator must monitor pH both in
ground water and any standing surface water adjacent to the impoundment, and if pH levels are outside of the
range of 6.5 to 9.0, notify the state and EPA immediately. The state is aware that some seepage from the
surface impoundment may be occurring, but has concluded that the seepage has not caused adverse
environmental affects. Utah recently enaaed new ground-water protection legislation that might address the
process wastewater managed at the Rowley facility, though the state has not yet issued any permits.
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Chapter 11: Magnesium Production 11-9
11.5 Waste Management Alternatives and Potential Utilization
Wastewater management alternatives are generally limited in scope to strategies for recycling, treating,
and/or disposing of the material. In the case of process wastewater from primary magnesium production, EPA
believes that management alternatives consist primarily of treating the wastewater (i.e., pH adjustment), and
either discharging the treated effluent to the existing evaporation impoundment or recycling it to the
magnesium production operation. Sludge generation as a result of such treatment would depend on the pH
of the treated wastewater and the treatment agent(s) employed. If sludge is generated by this management
scheme, it might require disposal in a RCRA Subtitle C facility (due to heavy metal content). The costs
associated with this waste management alternative are examined below in section 11.6.
11.6 Cost and Economic Impacts
Section 8002(p) of RCRA directs EPA to examine the costs of alternative practices for the
management of the special wastes considered in this report. EPA has responded to this requirement by
evaluating the operational changes that would be implied by compliance with three different regulatory
scenarios, as described in Chapter 2. In reviewing and evaluating the Agency's estimates of the cost and
economic impacts associated with these changes, it is important to remember what the regulatory scenarios
imply, and what assumptions have been made in conducting the analysis.
The focus of the Subtitle C compliance scenario is on the costs of constructing and operating
hazardous waste management units. Other important aspects of the Subtitle C system (e.g., corrective action,
prospective land disposal restrictions) have not been explicitly factored into the cost analysis. Therefore,
differences between the costs estimated for Subtitle C compliance and those under other scenarios (particularly
Subtitle C-Minus) are less than they might be under an alternative set of conditions (e.g., if most affected
facilities were not already subject to Subtitle C, if land disposal restrictions had been promulgated for "newly
identified" hazardous wastes). The Subtitle C-Minus scenario represents, as discussed above in Chapter 2, the
minimum requirements that would apply to any of the special wastes that are ultimately regulated as hazardous
wastes; this scenario does not reflect any actual determinations or preliminary judgments concerning the
specific requirements that would apply to any such wastes. Further, the Subtitle D-Plus scenario represents
one of many possible approaches to a Subtitle D program for special mineral processing wastes, and has been
included in this report only for illustrative purposes. The cost estimates provided below for the three scenarios
considered in this report must be interpreted accordingly.
In accordance with the spirit of RCRA §8002(p), EPA has focused its analysis on impacts on the firms
and facilities generating the special wastes, rather than on net impacts to society in the aggregate. Therefore,
the cost analysis has been conducted on an after-tax basis, using a discount rate based on a previously
developed estimate of the weighted average cost of capital to U.S. industrial firms (9.49 percent), as discussed
in Chapter 2. Waste generation rate estimates (which are directly proportional to costs) for the period of
analysis (the present through 1995) have been developed in consultation with the U.S Bureau of Mines.
In this section, EPA first outlines the way in which it has identified and evaluated the waste
management practices that would be employed under different regulatory scenarios by Magcorp's primary
magnesium production facility in Rowley, Utah. Next, the section discusses the cost implications of requiring
these changes to existing waste management practices. The last part of the section predicts and discusses the
ultimate impacts of any increased waste management costs faced by the facility.
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11-10 Chapter 11: Magnesium Production
11.6.1 Regulatory Scenarios and Required Management Practices
Based upon the information presented above, EPA believes that process wastewater from the Rowley
facility poses a low degree of hazard; the waste does, however, exhibit the hazardous characteristic of
corrosivity, based on EPA and industry sampling data. Accordingly, the Agency has estimated trie costs
associated with regulation under Subtitle C of RCRA, as well as with two somewhat less stringent regulatory
scenarios, referred to here as "Subtitle C-Minus" and "Subtitle D" (a more detailed description of the cost
impact analysis and the development of these regulatory scenarios is presented in Chapter 2, above). In the
following paragraphs, EPA discusses the assumed management practices that would occur under each
regulatory alternative.
Subtitle C
Under Subtitle C standards, hazardous waste that is managed on-site must meet the rigorous standards
codified at 40 CFR Part 264 for hazardous waste treatment, storage, and disposal facilities. Because
magnesium anhydrous process wastewater is a dilute, aqueous liquid that is corrosive but not EP toxic, the
management practice of choice under Subtitle C is treatment (neutralization) in a tank. EPA has determined
that within the relevant size range, tank treatment is the least-cost management method, and has conducted
its analysis accordingly. The scenario examined here involves construction of a Subtitle C surge pond (double-
lined surface impoundment), and a tank treatment system. Following neutralization, the treated process
wastewater may be reused by the facility or discharged to the existing surface impoundment, just as it is under
current practice. The treatment sludge, which is assumed to not be a hazardous waste, is disposed in an
unlined disposal impoundment/landfill.
Subtitle C-Minus
Assumed practices under Subtitle C-Minus are identical to those described above for the full
Subtitle C scenario, with the exception that some of the stria requirements for construction and operation
of the hazardous waste surge pond have been relaxed, most notably the liner design requirements. Because
other Subtitle C provisions apply in full, there are no significant operational differences between the two
scenarios.
Subtitle D-Plus
Assumed practices under Subtitle D-Plus are identical to those described above for the full Subtitle C
scenario, with the exception that, as under Subtitle C-minus, some of the stria requirements for construaion
and operation of the hazardous waste surge pond have been relaxed, most notably the liner design
requirements. Because other provisions that are analogous to Subtitle C controls apply under this scenario,
there are no significant operational differences between this and the other two scenarios.
11.6.2 Cost Impact Assessment Results
Results of the cost impaa analysis for the magnesium anhydrous processing sector are presented by
regulatory scenario in Exhibit 11-3. Under the Subtitle C scenario, annualized incremental regulatory
compliance costs are estimated for Magcorp's Rowley facility to be $123 million greater than baseline (over
4 times the baseline costs). Annualized incremental capital compliance expenditures are estimated at $286,000,
or approximately 23 percent of the total incremental compliance costs.
Under the somewhat less rigorous requirements of the Subtitle C-Minus scenario, costs of regulatory
compliance are lower, due to decreased capital construaion outlays. Magcorp's annualized compliance costs
under this scenario are estimated to be $1.18 million greater than baseline (about 4 times baseline costs). The
-------
Exhibit 11-3
Compliance Cost Analysis Results for Management of
Process Wastewater from Primary Magnesium Processing by the Anhydrous Process
(a)
Facility
Magcorp - Rowley. UT
Total:
DBVOllflw WrlvlQ
MMItttQMIMflt CO81
Annual Total
($000)
368
368
Incremental Costa of Regulatory Compliance
Subtitle C
Annual
Total
($000)
1,231
1,231
Total
Capital
($000)
I
1,918
1,918
Annual
Capital
($000)
286
286
Subtitle C-Mlnua
Annual
Total
($000)
1.183
1,183
Total
Capital
($000)
1.668
1,668
Annual
Capital
($000)
249
249
Subtitle D-Plus
Annual
Total
($000)
1.183
1.183
Total
Capital
($000)
1.668
1.668
Annual
Capital
($000)
249
249
o
•3
\
<0
I
c
TJ
(a) Values reported In this table are those computed by EPA's cost-estimating model, and are Included for Illustrative purposes. The data, assumptions, and computational
methods underlying these values are such that EPA believes that the compliance cost estimates reported here are precise to two significant figures.
o
3
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11-12 Chapter 11: Magnesium Production
total compliance cost for the sector is only about three percent less than under the full Subtitle C scenario.
The primary reason for the difference in waste management costs is the configuration of the surge pond liner
system; under the Subtitle C-Minus scenario, disposal units are equipped with a single synthetic liner and
leachate collection system, rather than the dual system required under full Subtitle C regulation.
Costs under the Subtitle D-Plus regulatory scenario are identical to those under Subtitle C-Minus
scenario. The configuration of the surge pond, the only varying factor between Subtitle C and C-minus, is the
same for D-Plus and C-Minus (installation of a composite liner with clean closure).
11.6.3 Financial and Economic Impact Assessment
To evaluate the ability of the affected facility to bear these regulatory compliance costs, EPA
conducted an impact assessment consisting of three steps. First, to assess the magnitude of the financial
burden that would be imposed in the absence of changes in magnesium supply, demand, or price, the Agency
calculated financial impact ratios by comparing the estimated compliance costs to several measures of the
financial strength of the facility. Next, in order to determine whether compliance costs could be distributed
to (shared among) other production input and product markets, EPA conducted a qualitative evaluation of
the salient market factors that affect the competitive position of domestic primary magnesium producers.
Finally, the Agency combined the results of the first two steps to arrive at predicted ultimate compliance-
related economic impacts on the facility. The methods and assumptions used to conduct this analysis are
described in Chapter 2 and in Appendices E-3 and E-4 (in Volume III) to this report.
Financial Ratio Analysis
EPA's ratio analysis indicates that regulation under any of the three scenarios would impose
marginally significant impacts on the one affected facility. The costs associated with management of process
wastewater under Subtitle C represent around one percent of value added (which in this case is the equal to
value of shipments), as shown in Exhibit 11-4. The only potentially significant impact is that of the required
annualized compliance capital as a percentage of current total annual sustaining capital investments; additional
capital above and beyond sustaining capital would be required to cover increased capital needs. The values
of this ratio are somewhat deceptive, however, since capital compliance costs are relatively low in magnitude
($250,000 to $286,000 annually). The results of the ratio analysis are high because sustaining capital, the
denominator in the ratio analysis, is relatively small because the plant and equipment used in the anhydrous
process do not require high levels of continual capital investments.
Market Factor Analysis
General Competitive Position
The United States imports little magnesium metal, most of it coming from Norway and Canada, and
is a net exporter of the metal. There are three companies producing magnesium metal in the United States.
Magcorp recovers magnesium from Great Salt Lake brines in Utah; Dow from seawater in Texas; and
Northwest Alloys from dolomite in W^hington state. Domestic production of magnesium metal increased
in 1988, with some facilities running at 100 percent of capacity. Production of magnesium metal from primary
processing facilities totaled 156,500 short tons in 1988 and overall, producers operated at 91 percent of the
industry's rated capacity. The estimated capacity for the sector will increase from 172,000 short tons in 1988
to 181,000 short tons in 1989. In addition, nearly 50,000 tons of raw and old scrap were recovered. These
trends are related to recent increases in U.S. demand for magnesium, which have also led to price increases
and temporary shortages.
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Chapter 11: Magnesium Production 11-13
Exhibit 11-4
Significance of Regulatory Compliance Costs for Mangement of
Process Wastewater from Primary Magnesium Processing
by the Anhydrous Process(a)
Facility
Subtitle C
Magcorp - Rowley, UT
Subtitle C-Mlnus
Magcorp - Rowley, UT
Subtitle D-Plus
Magcorp - Rowley, UT
CC/VOS
1.3%
1.2%
1.2%
CC/VA
1.3%
1.2%
1.2%
IR/K
9.5%
8.2%
8.2%
CC/VOS = Compliance Costs as Percent of Sales
CC/VA = Compliance Costs as Percent of Value Added
IR/K - Annualized Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported in this table are based upon EPA's compliance cost estimates. The Agency believes that these
values are precise to two significant figures.
Potential for Compliance Cost Pass-Through
Labor Markets. Approximately 450 people were employed in the U.S. in the primary production
of magnesium metal, though the number employed at Rowley is not known. The average salary was $26,652
per year. It is unlikely that there could be reductions in labor rates or staffing that could substantially mitigate
higher compliance costs.
Supply Markets. Magnesium is an abundant element and is primarily extracted from seawater and
well and lake brines. The supply of these materials is extremely low-cost, and free in many cases (e.g., brines
from the Great Salt Lake). For the affected facility, therefore, there is essentially no supply market that could
be induced to share any incremental compliance cost burden.
Higher Prices. Because only one of the three domestic producers would be subject to compliance
costs, higher prices would not be expected as a result of compliance. However, due to high capacity utilization,
it is unlikely that producers would be able to increase supply if demand were to rise. Therefore, if demand
for magnesium metals continues to increase, prices may rise somewhat There is little foreign competition in
this sector, so overseas supplies are unlikely to displace U.S.-made magnesium.
Evaluation of Cost/Economic Impacts
EPA believes that stringent regulation of magnesium process wastewater as a hazardous waste would
not impose highly significant economic or financial impacts on Magcorp's facility in Rowley, Utah. Estimated
Subtitle C compliance costs are moderate, though a large capital investment relative to current sustaining
capital would be required. Because of the strength of the domestic facilities in the magnesium market and
high current capacity utilization across the sector, EPA believes that facilities in the magnesium production
industry might be able to increase prices somewhat without seriously undercutting sales. Furthermore, EPAs
analysis suggests that Magcorp (the only facility that generates a special waste) could pass through a portion
of any regulatory compliance costs to product consumers, because demand for and prices of magnesium have
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11-14 Chapter 1.1: Magnesium Production
been strong in recent years, and are expected to remain so for the foreseeable future. Consequently, EPA
believes that regulation of process wastewater from-magnesium production by the anhydrous process under
RCRA Subtitle C would not threaten the long-term profitability or economic viability of the Magcorp facility.
11.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) potential for and documented
danger to human health and the environment; (2) the need for and desirability of additional regulation; and
(3) the costs and impacts of potential Subtitle C regulation
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of magnesium process wastewater is high to moderate as compared to the other
mineral processing wastes studied in this report. Measurement of pH for two samples of the process
wastewater indicate that the wastewater exhibits the hazardous waste characteristic of corrosivity, with a pH
of approximately 1. However, magnesium process wastewater contains only two constituents that exceed one
or more of the screening criteria used in this analysis by more than a factor of 10.
Despite the relatively high to moderate intrinsic hazard of this waste, current management practices
and environmental conditions appear to limit the potential for the wastewater to threaten human health or
the environment. Migration of contaminants from the wastewater pond has been observed, but the Utah
Bureau of Wkter Pollution Control has stated that the seepage "was of low volume and did not pose a
significant environmental or human health threat." This is partly because shallow ground water at the Rowley
site is saline and unuseable (it is hydraulically connected with the Great Salt Lake), and partly because the
pond is underlain by oolitic sand that may neutralize the low pH of the seepage. The pH of the seepage is
being monitored under the conditions of a State permit that requires the seepage to be prevented if
monitoring indicates that the pH is outside the acceptable range of 6.5 to 9. In addition, only a few
constituents of the wastewater were present at concentrations that exceeded the screening criteria.
Consequently, it is unlikely that releases from the impoundment would result in harmful contaminant
concentrations in the Lake or underlying aquifers.
The finding that the potential for danger to human health and the environment is generally low is
confirmed by the absence of documented cases of environmental damage. Releases of wastewater to the Great
Salt Lake have occurred in the past when rising lake levels flooded the impoundment used for wastewater
evaporation. The current impoundment, which was constructed to replace the flooded impoundment, has
higher and thicker dikes to prevent flooding by the lake.
Ukelihood That Existing Risks/Impacts Will Continue in the
Absence of Subtitle C Regulation
While the relatively high to moderate intrinsic hazard of the wastewater is unlikely to change in the
future, the waste management practices and environmental conditions that currently limit the potential for
significant threats to human health and the environment are expected to continue to limit risks in the future
in the absence of Subtitle C regulation. Despite the fact that this analysis is limited to the single site at which
the waste is currently managed, EPA believes that the conclusion of low hazard can be extrapolated into the
future because the environmental conditions in which the wastewater is managed are unlikely to change.
Management of the process wastewater is unlikely to expand beyond the location studied for two reasons.
First, the quantity of material involved makes it unlikely that the process wastewater would be managed off-
site. Second, development of new facilities in substantially different environmental settings is unlikely because
the Great Salt Lake provides the feedstock necessary for magnesium production by the anhydrous process.
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Chapter 11: Magnesium Production 11-15
The potential for increased risks in the future is further restricted by State regulation of the
wastewater evaporation impoundment. Although -the State of Utah excludes mineral processing wastes
generated at the Rowley facility from hazardous waste regulation, the State has required that the facility
maintain an NPDES no-discharge permit for its process wastewater surface impoundment and is tracking the
seepage from the impoundment, as discussed above. The State recently enacted new ground-water protection
legislation, and plans to consider the need for a ground-water discharge permit at the Rowley facility, though
the effect of such permit requirements on the management of the surface impoundment is not clear.
Costs and impacts of Subtitle C Regulation
Because EPA waste sampling data indicate that process wastewater from primary magnesium
production by the anhydrous process exhibits the hazardous waste characteristic of corrosivity, the Agency has
evaluated the costs and associated impacts of regulating this waste as a hazardous waste under RCRA
Subtitle C. As with the other aspects of this study, the Agency's cost and impact analysis is limited in scope
to the facility at Rowley, Utah.
Costs of regulatory compliance exceed Sl.l million annually under each of the three regulatory
scenarios. Costs under the full Subtitle C, Subtitle C-Minus, and Subtitle D-Plus scenarios are almost
identical, because adequately protective waste management unit design and operating standards are essentially
the same under all three scenarios, given the nature of the waste and the environmental setting in which it
is currently managed. EPAs economic impact analysis suggests that the operator of the potentially affected
facility (Magcorp) could pass through a portion of any regulatory compliance costs that it might incur to
product consumers, because demand for and prices of magnesium have been strong in recent years. Because
the costs of Subtitle C regulatory compliance would not impose significant immediate impacts on the affected
facility (less than one and a half percent of value added) and because the facility may have some ability to pass
any such costs through to product consumers through higher prices, EPA does not believe that a decision to
regulate process wastewater under Subtitle C would threaten the long-term profitability or viability of the
Rowley facility.
Finally, EPA is not aware of any significant recycling or utilization initiatives that would be hampered
by a change in the regulatory status of this waste. The process water is likely to be managed in much the same
way as it is currently, with the exception that it would be treated prior to discharge to the existing surface
impoundment. EPA does not believe that additional waste management requirements would materially
influence the production processes employed at or general operation of the affected facility.
-------
Chapter 12
Phosphoric Acid Production
The phosphoric acid production industry consists of 21 facilities that were active as of September
1989,1 employed the wet phosphoric acid production process, and generated two special wastes from mineral
processing: process wastewater and phosphogypsum. The data included in this chapter are discussed in
additional detail in a technical background document in the supporting public docket for this report.
12.1 Industry Overview
There are two processes for producing phosphoric acid: (1) the wet process, which is a mineral
processing operation and is studied here, and (2) the furnace process. Furnace process phosphoric acid
production uses elemental phosphorus rather than beneficiated phosphate rock as a feedstock and, therefore,
wastes generated by the process are not mineral processing special wastes according to the Agency's definition
of mineral processing. Consequently, furnace process production of phosphoric acid is not within the scope
of this report.
About 95 percent of the commercial phosphoric acid produced by the wet process is used in the
production of fertilizers and animal feed, with a small portion used as a feedstock in chemical processing
operations.2 Typically, the fertilizer and feed plants are co-located with the phosphoric acid facilities.
As shown in Exhibit 12-1, the majority of the 21 active wet process facilities are located in the
southeast, with 12 in Florida, three in Louisiana, and one in North Carolina. Production data and dates of
initial operation and modernization were provided by all 21 facilities, although two claimed confidential status
for their information. The dates of initial operation for the 19 non-confidential facilities ranges from 1945
to 1986.3 Most of these facilities have undergone modernization within the last ten years, although six
facilities have not been upgraded in over 20 years. The 19 reporting non-confidential facilities have a
combined annual production capacity of over 11 million metric tons and a 1988 aggregate production of nearly
8.5 million metric tons; the 1988 capacity utilization rate, therefore, was approximately 77 percent. Several
facilities, however, operated at low utilization rates (i.e. three facilities reported rates of 15.8, 30.1 and 37.5
percent).
The fertilizer industry, the largest user of phosphoric acid, suffered poor financial conditions for much
of the 1980s. These conditions were the result of low domestic demand and reduced foreign buying. Domestic
demand for phosphoric acid was boosted by the 1988 recovery of the farm economy and was expected to
continue to grow as crop prices and planted acreage increased in 1989. Non-fertilizer uses of phosphoric acid
declined during the 1980s due to strict regulations governing the use of phosphates in household products and
a decline in industrial demand.4
The wet process consists of three operations: digestion, filtration, and concentration, as shown in
Exhibit 12-2.5 Beneficiated phosphate rock is dissolved in phosphoric acid; sulfuric acid is added to this
solution and chemically digests the calcium phosphate. The product of this operation is a slurry that consists
1 At least two facilities were on standby in 1988, Agrico's Ft. Madison, Iowa and Hahnville (Taft), Louisiana facilities; they are not
included in this analysis.
2 Bureau of Mines, 1987. Minerals Yearbook. 1987 Ed., p. 676.
3 Phosphoric acid producers, 1989. Company Responses to the "National Survey of Solid Wastes from Mineral Processing Facilities,"
U.S.EPA, 1989.
4 Standard & Poor's, "Chemicals: Basic Analysis,* Industry Surveys. October 13,1988 (Section 3), p. C20.
5 Environmental Protection Agency, 1986. Evaluation of Waste Management for Phosphate Processing. Prepared by PEI Associates
for U.S. EPA, Office of Research and Development, Cincinnati, OH, August, 1986.
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12-2 Chapter 12: Phosphoric Acid Production
Exhibit 12-1
Wet Processing Phosphoric Acid Plants
Operator
Agrico
Agrico
Agrico
Arcadian
Central Phos.
CF Chemicals
Chevron Chem.
Conserv
Farmland Inct
Fort Meade Chem.
Qar
-------
Chapter 12: Phosphoric Acid Production 12-3
Exhibit 12-2
Phosphoric Acid Production
PROCESS
Benefieioted
Sulfuric Phosphate
Acid Rock (BPR)
SPECIAL WASTE
MANAGEMENT
Phosphoric
Acid Production
BPRI
Process Wastewater
Phosphogypsum
Hydrofluosflicic Acid
(Optional) ^
Phosphoric
Acid
Super
Phosphate
Acid
Production
(Optional)
Non-Ammonioted
Animal Feed
(Optional)
BPR.
.Limestone
and/or
Soda Ash
' /\
/ Storage \
-,—d Surface
I \lmpoundmeny
1 1
Return to
, Production
NPDES
Discharge
Merchant Grade
Phosphoric
Acid
Legend
I 1 Production Operation
Special Waste
O
Waste Management Unit
12.2 Waste Characteristics, Generation, and Current Management Practices
12.2.1 Phosphogypsum
Phosphogypsum, which has an average particle diameter of less than 0.02 millimeters, is primarily
composed of calcium sulfate, silicon, phosphate, and fluoride. It also typically contains a variety of
radionuclides, including uranium-230, uranium-234, thorium-230, radium-226, radon-222, lead-210 and
polonium-210.
Using available data on the composition of phosphogypsum, EPA evaluated whether leachate from
this material exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and
extraction procedure (EP) toxicity. Based on available information and professional judgment, the Agency
does not believe phosphogypsum is reactive, corrosive, or ignitable. Some phosphogypsum samples, however,
exhibit the characteristic of EP toxicity. EP leach test concentrations of all eight inorganic constituents with
EP toxicity regulatory levels are available for 28 phosphogypsum samples from 11 facilities of interest. Of
these constituents, only chromium concentrations exceed the EP toxicity levels; this occurred in 2 of 28
samples analyzed, by as much as a factor of 9. Both samples that failed the EP toxicity criterion for chromium
-------
12-4 Chapter 12; Phosphoric Acid Production
were from the Rock Springs facility. The phosphogypsum samples that failed the EP toxic level were also
analyzed using the SPLP leach test, and for both samples, concentrations of chromium measured by the SPLP
leach test were well below the EP toxicity regulatory levels.
Non-confidential waste generation rate data were reported for phosphogypsum by 18 of the 21
processing facilities and estimated for the remaining three. The aggregate annual industry-wide generation
of phosphogypsum was approximately 47.6 million metric tons in 1988, yielding a facility average of about 2.26
million metric tons per year. Reported facility generation rates ranged from .14 to 6.8 million metric tons of
phosphogypsum. The sector-wide ratio of phosphogypsum to phosphoric acid ranges from 3.7 to 5.6, averaging
4.9 for the sector.
Phosphogypsum is managed in basically the same way at virtually all of the 21 active facilities. The
phosphogypsum removed by the filtration step in the phosphoric acid production process is slurried in process
wastewater and pumped to one or more impoundments located on the top of an on-site waste pile known in
the industry as a gypsum stack. In the impoundment, the gypsum solids are allowed to settle; the liquid
(process wastewater) is either directly removed from the settling pond and sent to a nearby cooling pond or
indirectly removed after it seeps though the stack and is collected by ditches or ponds that circumscribe the
stack.
Periodically, the phosphogypsum slurry is diverted from one impoundment on the gypsum stack to
another and the first impoundment is allowed to dry. The dewatered phosphogypsum is excavated from the
inactive pond and used to build up the dike that forms the impoundment and then the impoundment is
returned to active service. In this manner, the stack with its series of settling ponds increases in height and
accumulates additional phosphogypsum. The ultimate height and area of the resulting stack depends on the
configuration of the facility's property and the ability of the native soils to support the load of the stack. After
a stack is "full", rainwater that runs off or leaches through the stack continues to be collected in the perimeter
ditch and is usually managed with water collected from active stacks.
The average dimensions of the gypsum stacks are 130 hectares ^320 acres) at the base and 35 meters
(115 feet) in height; on a facility-specific basis the stacks range from about 20 to 260 hectares and 3 to 130
meters in height. The average dimensions of the settling ponds atop these stacks are 54 hectares and 1.4
meters in depth; on a facility-specific basis the ponds range in size from 2.6 to 26 hectares and in depth from
.3 to 7.6 meters.
12.2.2 Process Wastewater
Process wastewaters are generated at several points in phosphoric acid production, including
phosphoric acid concentration, and phosphoric acid temperature control and cooling. These wastewaters
contain significant quantities of chloride, fluoride, phosphate, and have a pH that ranges from 0.5 to 7.8.
Using available data on the composition of phosphoric acid process wastewater, EPA evaluated
whether the wastewater exhibits any of the four characteristics of hazardous waste: corrosivity, reactivity,
ignitability, and extraction procedure (EP) toxicity. Based on available information and professional judgment,
the Agency does not believe the wastewater is reactive or ignitable. Some wastewater samples, however,
exhibit the characteristics of corrosivity and EP toxicity. Measurements of pH in 42 out of 68 process
wastewater samples from a total of 14 facilities indicated that the wastewater was corrosive, sometimes with
pH values as low as 0.5 (the lower bound pH limit for the purpose of defining corrosive waste is 2.0). EP
leach test concentrations of all eight constituents with EP toxicity regulatory levels are available for process
wastewaters from 7 facilities. Of these constituents, cadmium and chromium concentrations were found to
sometimes exceed the EP toxicity levels, and one sample was found to have a selenium concentration equal
to the EP toxicity regulatory level. Concentrations of cadmium exceeded the EP toxic level in process
wastewater samples from three facilities, Pocatello, Geismar, and Aurora. Cadmium was present at
concentrations in excess of the EP toxic level in 19 out of 30 samples by as much as a factor of 8. From a
total of 30 samples, chromium concentrations exceeded the EP toxicity regulatory level (by as much as a factor
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Chapter 12: Phosphoric Acid Production 12-5
of 2.7) in only 3 samples (2 of which were from the Pocatello facility and 1 from the Pascagoula facility).
SPLP leach test results for phosphoric acid process wastewater samples were well below the EP toxicity
regulatory levels for all constituents.
Non-confidential waste generation rate data were fully reported for process water by 12 of the 21
processing facilities and estimated for the remaining nine. The aggregate annual industry-wide generation of
process water was approximately 1.77 billion metric torts (468 billion gallons) in 1988, yielding a facility
average of 84 million metric tons per year (60 million gallons per day [mgd]). Reported facility annual
generation rates ranged from 13 to 280 million metric tons of process wastewater (9.3 to 200 mgd). The ratio
of process water managed to phosphoric acid produced ranges from 102 to 494.
The process wastewater from the stacks, along with non-transport process waters, are typically
managed in on-site impoundments, commonly known as cooling ponds. These impoundments are used in
conjunction with the gypsum stacks in an integrated system, \\fcter from these ponds is reused in on-site
mineral processing and other activities. The facility operators ideally seek to maintain a water balance such
that no treatment and discharge of process wastewater to surface water is necessary, although some facilities
are equipped to treat and discharge some wastewater during periods of high precipitation.
The average dimensions of the cooling ponds are nearly 60 hectares (145 acres) of surface area and
2.6 meters (8.5 feet) of depth; on a facility-specific basis the surface area ranges from 1 to 260 hectares (2.5
to 640 acres) and depth ranges from 0.3 to 6.7 meters (1 to 21 feet).
12.3 Potential and Documented Danger to Human Health and The Environment
This section addresses two of the study factors required by §8002(p) of RCRA: (1) potential danger
(i.e., risk) to human health and the environment; and (2) documented cases in which danger to human health
or the environment has been proven. The Agency's evaluation of the potential dangers posed by
phosphogypsum and phosphoric acid process wastewater uses the evidence presented in numerous documented
cases of danger to human health and the environment to establish that these wastes can threaten human health
and the environment as they are currently managed. Overair conclusions about the hazards associated with
phosphogypsum and phosphoric acid process wastewater are provided after these two study factors are
discussed.
12.3.1 Risks Associated With Phosphogypsum and
Phosphoric Acid Process Wastewater
Any potential danger to human health and the environment from phosphogypsum and phosphoric
acid process wastewater depends on the presence of toxic and radioactive constituents in the wastes that may
present a hazard and the potential for exposure to these constituents. The Agency has documented cases of
dangers posed by these wastes via ground and surface water pathways (see Section 12.3.2), and has previously
evaluated potential air pathway dangers from the management of phosphogypsum in stacks. Based on the
insights provided by analyses of the hazards posed by phosphogypsum and phosphoric acid wastewater, and
information on waste characteristics and management developed for this study, the Agency evaluated the
intrinsic hazard of these wastes and the potential for toxic and radioactive constituents from these wastes to
pose threats to human health and the environment. This evaluation discusses constituents of potential concern
in the wastes and assesses the management practice and environmental setting characteristics that affect the
potential for these wastes to pose risks through the ground-water, surface water, and air pathways.
Phosphogypsum Constituents of Potential Concern
EPA identified chemical constituents in phosphogypsum that may present a hazard by collecting data
on the composition of this waste and evaluating the intrinsic hazard of the chemical constituents.
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12-6 Chapter 12: Phosphoric Acid Production
Data on Phosphogypsum
EPA's characterization of phosphogypsum and its leachate is based on data from three sources: (1)
a 1989 sampling and analysis effort by EPA's Office of Solid 'Waste (OSW); (2) industry responses to a RCRA
§3007 request; and (3) sampling and analysis conducted by EPAs Office of Research and Development (ORD)
in 1986. These data provide information on the concentrations of 21 metals, radium-226, thorium-232,
uranium-238, gross alpha and beta radiation, a number of other inorganic constituents (i.e., phosphate,
phosphorus, fluoride, chloride, sulfate, ammonia, and nitrate), and five organic constituents in total and leach
test analyses. Thirteen of the 21 phosphoric acid production facilities are represented by these data.
Concentrations of most (i.e., 21 of 38) constituents in solid samples of phosphogypsum vary
considerably among the samples analyzed (i.e., the range of values spans more than three orders of magnitude).
Concentration data provided by industry represent a larger number of samples and span a wider range of
values than do data from EPA's sampling and analysis efforts. EPA sampling and analysis data for some
constituents (i.e., arsenic, selenium, silver, and thallium) do not contribute to the characterization of
phosphogypsum because the detection limits used in analyzing these samples are higher than any detected
concentrations from analyses of other samples.
Concentrations of most constituents in leach test analyses of phosphogypsum vary considerably less
than do concentrations in solid samples (i.e., the ranges of values span less than two orders of magnitude).
However, concentrations of chromium, copper, iron, lead, and zinc in EP leach test analyses vary over three
or more orders of magnitude. Concentrations from analyses using the EP leach test method are consistently
higher than from SPLP method analyses.
Process for Identifying Constituents of Potential Concern
As discussed in Chapter 2, the Agency evaluated the waste composition data summarized above to
determine if phosphogypsum contains any chemical constituents that could pose an intrinsic hazard. The
Agency performed this evaluation by first comparing the concentration of chemical constituents to screening
criteria that reflect the potential for hazards, and then by evaluating the environmental persistence and
mobility of constituents that are present at levels above the criteria. These screening criteria were developed
using assumed scenarios that are likely to overestimate the extent to which constituents in phosphogypsum
are released to the environment and migrate to possible exposure points. As a result, this process eliminates
from further consideration only those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic ecosystems, and air and surface/ground water resources (see Exhibit 2-3). Given the
conservative (i.e., protective) nature of these screening criteria, contaminant concentrations in excess of the
criteria should not, in isolation, be interpreted as proof of hazard. Instead, exceedances of the criteria indicate
the need to evaluate the potential hazards of the waste in greater detail.
Identified Constituents of Potential Concern
Exhibits 12-3 and 12-4 present the results of the comparisons for phosphogypsum solid analyses and
leach test analyses, respectively, to the screening criteria described above. These exhibits list all constituents
for which at least one sample concentration exceeds a relevant screening criterion.
Of the 38 constituents analyzed in total analyses of phosphogypsum, only radium-226, uranium-238,
chromium, and arsenic are present at concentrations exceeding the screening criteria (Exhibit 12-3). Maximum
concentrations of these constituents are at most seven times the screening criteria. The sample concentrations
of the first three of these constituents (i.e., all except arsenic) exceed screening criteria in at least half of the
-------
Chapter 12: Phosphoric Acid Production 12-7
Exhibit 12-3
Potential Constituents of Concern in Phosphogypsum Solids^
Potential
Constituents
of Concern
Radium-226
Uranium-238
Chromium
Arsenic
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
29/29
18/18
34/43
35/43
Human Health
Screening Criteria'1"
Radiation***
Radiation*'0'
inhalation*
Ingestion*
Inhalation*
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
26/29
1 /18
8/43
34/43
29/43
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
6/7
1 /3
4/8
2/8
1/8
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10"5 lifetime cancer
risk; others are based on noncancer effects.
(c) Includes direct radiation from contaminated land and inhalation of radon decay products.
facilities analyzed. None of these constituents, however, exceed the screening criteria by more than a factor
of 10.
• Radium-226, and uranium-238 concentrations exceed health-based screening criteria
based on multiple radiation pathways. Exceedance of these criteria indicates that
phosphogypsum could pose an unacceptable radiation risk if used in an unrestricted
manner (for instance, direct radiation doses and doses from the inhalation of radon
could be unacceptably high if phosphogypsum is used around homes).
• Chromium and arsenic concentrations exceed the health-based screening criteria for
inhalation. This indicates that these constituents could pose a significant cancer risk
(i.e., greater than IxlO"5) if phosphogypsum were released to the ambient air as
particles.
• Arsenic concentrations exceed the health-based screening criteria for incidental
ingestion. This indicates that arsenic may pose a significant incremental lifetime health
risk (i.e., greater than IxlO'5) if a small quantity of phosphogypsum or soil contaminated
with phosphogypsum is inadvertently ingested on a routine basis (e.g., airborne waste
particles may be deposited on crops, or small children playing on abandoned stacks
could inadvertently ingest the waste).
EPA sampling and analysis also indicates that levels of gross alpha and beta radiation from
phosphogypsum are very high (10 to 100 pCi/g) relative to levels associated with typical soils (approximately
1 pCi/g).
Based on a comparison of leach test concentrations of 29 constituents to surface and ground-water
pathways screening criteria (see Exhibit 12-4), 17 constituents were found to be of potential concern for water-
based release and exposure. Among these 17 constituents, phosphorus, arsenic, lead, phosphate, manganese,
molybdenum, and nickel exceed screening criteria in at least one-half of all facilities analyzed. Twelve
constituents exceed the screening criteria by more than a factor of 10, but only chromium was measured in
concentrations that exceed the EP toricity regulatory level. All of these constituents are very persistent in the
environment.
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12-8 Chapter 12: Phosphoric Acid Production
Exhibit 12-4
Potential Constituents of Concern in Phosphogypsum Leachate^
Potential
Constituents
of Concern
Phosphorus
Arsenic
Lead
Phosphate
Manganese
Molybdenum
Nickel
Iron
Cadmium
Chromium
Silver
Fluoride
Zinc
Antimony
Copper
Mercury
Thallium
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
17/17
19/28
14728
19/19
21 122
16/20
19/22
20/20
26/28
27/28
14/26
17/17
21 /22
5/22
18/22
3/24
1/20
Screening Criteria0*'
Aquatic Ecological
Human Health*
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
Resource Damage
Resource Damage
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
Human Health
Human Health
flaaouree Damage
Aquatic Ecological
Human Health
Human Health
Resource Damage
Aquatte Ecological
Aquatic Ecological
HtiRian Healtn
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
17/17
19/28
4/28
12/28
2/28
19/19
9/22
10/22
2/22
10/20
6/20
1 /20
4/2&
7/28
7/28
2/28
5/28
4/28
6/26
3/17
1/22
1/22
2/22
3/22
1/22 .
=' 1/22
4/22
1 /24
1/20
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
9/9
10/ 11
3/11
7/11
2/11
9/9-
6/11
6/10
2/11
6/11
4/10
1 MO
3/11
4/11
4/11
1/11
3/11
2/11
3/10
2/9
1/11
1/11
2/11
2/11
1/11
1/11
2/11
1 /10
1/10
(a)
(b)
Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. The constituent
concentrations used for this analysis are based on EP leach test results.
Human health screening criteria are based on cancer risk or noncancer health effects. 'Human health* screening criteria
noted with an •*' are based on 1x10"* lifetime cancer risk; others are based on noncancer effects.
-------
Chapter 12: Phosphoric Acid Production 12-9
These exceedances of the screening criteria have the following implications:
• Concentrations of arsenic, lead, cadmium, chromium, fluoride, zinc, antimony, copper,
and thallium in phosphogypsum leachate exceed screening criteria based on human
health risks. This indicates that, if phosphogypsum leachate were diluted less than 10-
fold during migration to a drinking water exposure point, long-term chronic ingestion
could cause adverse health effects due to the presence of these constituents. The
concentration of arsenic in diluted phosphogypsum leachate could pose a cancer risk of
greater than IxlO"5 from long-term drinking water exposures.
• Concentrations of phosphorus, lead, phosphate, nickel, iron, cadmium, chromium, silver,
zinc, copper, and mercury in phosphogypsum leachate exceed screening criteria for
protection of aquatic life. This means that phosphogypsum leachate could present a
threat to aquatic organisms if it migrates (with less than 100-fold dilution) to surface
waters.
• Lead, manganese, molybdenum, nickel, iron, cadmium, chromium, zinc, and copper
concentrations in phosphogypsum leachate exceed ground and surface water resource
damage screening criteria. This indicates that, if released and diluted by a factor of 10
or less, leachate from this waste may contain these constituents in concentrations
sufficient to severely restrict the potential future uses of nearby ground and surface
water resources.
These exceedances of the screening criteria, by themselves, do not demonstrate that phosphogypsum
poses a significant risk, but rather indicate that it may present a hazard. Ib determine the potential for
phosphogypsum to cause significant impacts, EPA proceeded to analyze the actual conditions that exist at the
facilities that generate and manage the waste (see the following section on release, transport, and exposure
potential).
Process Wastewater Constituents of Potential Concern
Using the same process summarized above for phosphogypsum, EPA identified chemical constituents
in phosphoric acid process wastewater that could conceivably pose a risk by collecting data on the composition
of this waste, and evaluating the intrinsic hazard of the chemical constituents present in the process
wastewater.
Data on Process Wastewater Composition
EPAs characterization of process wastewater and its leachate is based on data from: (1) a 1989
sampling and analysis effort by EPA's Office of Solid V&ste (OSW), and (2) industry responses to a RCRA
§3007 request. These data provide information on the concentrations of 21 metals, radium-226, uranium-238,
gross alpha and gross beta radiation, a number of other inorganic species (i.e., chloride, fluoride, phosphate,
nitrate, sulfate, and ammonia), and seven organic compounds in total and leach test analyses. Data on the
pH of process wastewater was also collected: at most facilities, the pH is between 1 and 2 standard units,
however, two facilities report minimum levels below 1, and 1 facility reports levels between 6.5 and 8 standard
units. The waste composition data represent samples collected from 17 of the 21 active phosphoric acid
production facilities. As with the concentration data for phosphogypsum, data on the concentrations of most
constituents in process wastewater vary over two or three orders of magnitude. Concentrations from leach
test analyses of the wastewater vary to a smaller extent
Concentrations of most (i.e., 22 of 40) constituents in total analyses of process wastewater vary
considerably among the samples analyzed (i.e., the range of values spans more than three orders of magnitude).
Concentration data provided by industry represent a larger number of samples and span a wider range of
values than do data from EPA's sampling and analysis efforts. Concentrations of most constituents in leach
test analyses of process wastewater vary considerably less than do concentrations in total analyses (i.e., the
ranges of values span two or three orders of magnitude for only five constituents). Because the waste
-------
12-10 Chapter 12: Phosphoric Acid Production
characterization provided by total analyses and leach test analyses are similar, and because the quantity of data
is much greater for total analyses, the following analysis of potential constituents of concern in process
wastewater is based on the results of total analyses only.
Identified Constituents of Potential Concern
Exhibit 12-5 presents the results of the comparisons for the phosphoric acid process wastewater total
analyses to the screening criteria described above. This exhibit lists all constituents for which at least one
sample concentration exceeds a relevant screening criterion.
Of the 40 constituents analyzed in process wastewater (and its leachate), levels of arsenic, phosphorus,
phosphate, cadmium, chromium, aluminum, gross alpha and beta radiation, radium-226, phenol, iron,
manganese, nickel, lead, vanadium, sulfate, copper, boron, molybdenum, antimony, thallium, silver, cobalt,
mercury, fluoride, zinc, chloride, beryllium, selenium, and pH exceed the Agency's screening criteria. All of
these constituents are metals or other inorganics that do not degrade in the environment.
The first 22 of these 30 constituents are of relatively greater potential concern because their
concentrations in samples from at least one-half of all facilities analyzed exceed screening criteria (based on
separate evaluations of total liquid and leach test results). Maximum concentrations of phosphorus,
phosphate, arsenic, and phenol exceed screening criteria by factors of greater than 1,000 and concentrations
of 15 other constituents exceed screening criteria by factors of at least 10. As discussed in Section 12.2,
cadmium, chromium, and selenium concentrations are occasionally greater than or equal to the EP toxicity
regulatory levels, and the pH is frequently below 2.0, the lower-bound limit for defining a corrosive waste.
These exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• Concentrations of arsenic, cadmium, chromium, radium-226, lead, vanadium, copper,
antimony, thallium, fluoride, and selenium in process wastewater exceed screening
criteria based on human health risks. This indicates that, if process wastewater was
diluted 10-fold during migration to a drinking water exposure point, long-term
exposures could cause adverse health effects due to the presence of these constituents.
Based on long-term drinking water exposures, arsenic concentrations could pose a
significant cancer threat (i.e., a lifetime risk of greater than IxlO'5).
• Concentrations of arsenic, cadmium, chromium, aluminum, gross alpha and beta
radiation, radium-226, phenol, iron, manganese, nickel, lead, vanadium, sulfate, copper,
boron, molybdenum, cobalt, silver, fluoride, chloride, beryllium, and selenium in process
wastewater exceed ground and surface water resource damage screening criteria. This
indicates that, if released and diluted less than 10-fold in ground water or less than 100-
fold in surface water, phosphoric acid process wastewater may contain these constituents
in concentrations sufficient to severely restrict the uses of nearby ground- and surface
water resources. In addition, the pH of phosphoric acid plant process wastewater is very
low, and water resources may be damaged by the highly acidic nature of this waste.
• Concentrations of arsenic, phosphorus, phosphate, cadmium, chromium, aluminum, iron,
nickel, lead, copper, silver, mercury, zinc, and selenium in process wastewater exceed
screening criteria based on aquatic life protection. The low pH of the wastewater is also
well below the levels that most aquatic life can tolerate. This means that phosphoric
acid plant process wastewater may present a threat to aquatic organisms if it migrates
(with 100-fold dilution) to surface waters.
These exceedances, by themselves, do not prove that the wastewater poses a significant risk, but rather
indicate that it may present a hazard under a very conservative, hypothetical set of release, transport, and
exposure conditions. To determine the potential for this waste to cause significant impacts, EPA proceeded
to the next step of the risk assessment to analyze the actual conditions that exist at the facilities that generate
and manage the wastewater.
-------
Chapter 12: Phosphoric Acid Production 12-11
Exhibit 12-5
Potential Constituents of Concern in Phosphoric Acid Process Wastewater (Total)(a>
Potential
Constituents
of Concern
Arsenic
Phosphorus
Phosphate
Cadmium
Chromium
Aluminum
Grow Alpha
Gross Beta
Radiym-226
Phenol
Iron
Manganese
Nickel
Lead
Vanadium
Sulfate
Copper
No. of Time*
Constituent
Detected/No, of
Analyses
for Constituent
77/78
31 /31
38/38
73/77
75/78
58/59
46/47
34/47
86/89
4/5
54/55
44/44
68/72
64/75
38 /4T
57/57
68/74
Screening Criteria04
Human Health*
Resource Damage
Aquatic Ecological
Aquatic Ecological
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Resource Damage
Human Health'
Resource Damage
Resource Damage
Resource Damage
Aquatic Ecological
Resource Damage
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
rfUffUU): rittwtn
Resource Damage
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
No. of Analyse*
Exceeding Criteria/
No. of Analyses for
Constituent
76/78
37/78
21/78
31 /31
38/38
65/77
69/77
68/77
26/78
65/78
44/78
42/59
53/59
40/47
30/47
26/89
14/89
4/5
52/55
33/55
41 /44
14/72
57/72
28/75
51 /75
22/75
ie/4i
30/41
43/57
1/74
1/74
37/74
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
15/15
8/15
5/15
10/ 10
9/9
14/15
14/15
14/15
8/15
14/15
9/15
8/10
10/10
11 /11
9/9
9/13
5/13
3/3
10/10
6/10
10/10
8/14
12/14
8/15
12/15
7/15
5/10
9/10
10/11
1/14
1/14
7/14
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. 'Human health* screening criteria
noted with an •*• are based on 1x10'5 lifetime cancer risk; others are based on noncancer effects.
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12-12 Chapter 12: Phosphoric Acid Production
Exhibit 12-5 (cont'd)
Potential Constituents of Concern in Phosphoric Acid Process Wastewater (Total)
Potential
Constituents
of Concern
Boron
Molybdenum
Antimony
Thallium
Cobalt
Silver
Mercury
Fluoride
Zinc
Chloride
Beryllium
Selenium
pH
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
2/2
34/39
27/70
18/56
35/41
43/73
45/74
53/53
77/77
26/26
66/71
56/73
68/68
Screening Criteria**"
Resource Damage
Resource Damage
Human Hearth
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
1 /2
27/39
10/70
18/56
7/41
12/73
6/74
3/53
1 /53
9/77
2/26
2/71
1 /73
2/73
2/73
59/68
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
1 /1
10/10
6/14
5/13
3/10
5/14
4/14
1 /12
1/12
3/14
1 /6
1/.14
1 /14
1 /14
1 /14
13/14
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. 'Human hearth* screening criteria
noted with an '*' are based on 1x10'5 lifetime cancer risk; others are based on noncancer effects.
Release, Transport, and Exposure Potential
This analysis evaluates the baseline hazards of phosphogypsum and phosphoric acid plant process
wastewater as it was generated and managed at the 21 phosphoric acid facilities in 1988. It does not assess
the hazards of off-site use or disposal of these wastes or the risks associated with variations in waste
management practices or potentially exposed populations in the future because of a lack of data on off-site
and projected future conditions.
EPA has identified a variety of documented cases of dangers posed by the release of constituents from
these wastes to the environment, and EPA's Office of Air and Radiation (OAR) has studied air pathway risks
(from radionuclides) posed by these wastes. Consequently, the Agency has used information on documented
and potential damages from these other analyses to support its evaluation of the release, transport, and
exposure potential of the current management of these wastes.
-------
Chapter 12: Phosphoric Acid Production 12-13
Ground-Water Release, Transport, and Exposure Potential
Section 12.3.2 describes documented cases of ground-water contamination at seven phosphoric acid
plants located in Central Florida (3), Louisiana (2), North Carolina (1), and Idaho (1). These cases indicate
that phosphogypsum and process wastewater constituents have been released to ground water at a number of
facilities and, at some sites, have migrated off-site to potable wells in concentrations that are well above hazard
criteria. Based on the analysis of the damage case evidence, presented below, EPA concludes that management
of phosphogypsum and process wastewater in stacks and ponds can release contaminants to the subsurface,
and depending on the hydrogeologic setting and ground-water use patterns, threaten human health via drinking
water exposures or render ground-water resources unsuitable for potential use.
In the following paragraphs, EPA presents a region-by-region assessment of the hazards posed by
phosphogypsum and process wastewater management. For purposes of this discussion, phosphoric acid plants
are grouped into the following eight regions: Central Florida, North Carolina, Louisiana, Idaho, North
Rorida, Mississippi, Texas, and Wyoming. For each region for which ground-water damages have been
documented, the Agency first builds the case that damages attributable to waste management have occurred,
then, to the extent necessary, uses environmental setting information to assess the potential hazards (i.e.,
health risks and resource damage potential) at other facilities in the region. When no damage case
information is available for a region, evidence of release potential is used in conjunction with environmental
setting information to assess the hazards of potential releases from the plants in these regions.
Central Florida. The Florida Department of Environmental Regulation has initiated enforcement
actions in response to ground-water contamination associated with the management of phosphogypsum and
process wastewater at all 11 active phosphoric acid production facilities in Central Rorida. At three of these
facilities (i.e., Central Phosphates, Seminole, and IMC) contamination of the useable intermediate or Roridan
aquifers exceeds primary drinking water standards for pH, gross alpha radiation, radium, sodium, total
dissolved solids, sulfate, cadmium, chromium, fluoride, and arsenic beyond the permitted zone of discharge.7
With the exception of sodium and total dissolved solids, all of these constituents were identified as potential
constituents of concern in phosphogypsum or process wastewater. At the other eight facilities, contamination
exceeding drinking water standards beyond the permitted zone of discharge has been detected only in the
surficial aquifer. Two of the three damage cases for Central Rorida phosphoric acid production plants
presented in Section 12.3.2 (i.e., Central Phosphates and Seminole) discuss contamination of off-site ground
water in formations that are used for water supplies. At Central Phosphates, a ground-water contamination
plume in the Roridan aquifer extends six acres beyond the facility boundary; contamination of the surficial
aquifer covers 28 acres outside the facility boundary. Twelve of 18 potable supply wells down-gradient of the
Seminole plant sampled in 1988 contained at least one constituent at a concentration in excess of a drinking
water standard. The owner of the phosphoric acid plant paid to have the affected properties connected to a
public water supply. These ground-water contamination incidents indicate a high potential for ground-water
releases from the phosphoric acid production plants in Central Rorida. Except for the Gardinier facility, all
operating plants in this area are within 1,000 meters of a public supply well and contamination of the Roridan
aquifer at these sites could pose a public health threat via drinking water exposures. As demonstrated by the
damage cases and violations of drinking water standards beyond the permitted zone of discharge, contaminants
from these wastes can reach the useable aquifer in this area and migrate down-gradient toward potential
exposure points.
North Carolina. Section 12.3.2 discusses ground-water contamination resulting from management
of process wastewater at the phosphoric acid plant in Aurora, North Carolina. The extent of ground-water
contamination at this site is not known with certainty, but fluoride and total dissolved solids concentrations
in on-site wells exceed state drinking water standards in the surficial aquifer that is not extensively used and
7 The State of Florida allows discharges to ground water within a defined "zone of discharge." The horizontal extent of the zone
typically is limited to the property boundary.
-------
12-14 Chapter 12: Phosphoric Acid Production
in an intermediate aquifer that is useable, but not developed in the vicinity of the site. No contamination has
been detected in a deeper aquifer that serves as the principal water supply in this area. Although off-site
migration of contaminants and contamination of the principal water supply aquifer have not been documented,
exposures could occur if contaminated drinking water were withdrawn from the surficial aquifer at nearby
residences (as close as 100 meters). Even though ground water in the surficial and intermediate aquifers is
not currently used as a drinking water source, the documented contamination may render ground water
beneath the facility, and possibly down-gradient of the facility, unsuitable for potential future uses.
Louisiana. Documented cases of ground-water damages from phosphogypsum and process
wastewater management at two plants in Louisiana are presented in Section 12.3.2. Data provided in the
damage cases indicates that ground water beneath the Geismar facility is contaminated with gross alpha
radiation at concentrations more than six times the federal primary drinking water standard. In addition, the
Louisiana Department of Environmental Quality concluded in 1986 that "contamination of the shallow ground
water [at Donaldsonville], although by constituents which are not of great concern, poses a threat to drinking
water."8 Current human health threats via drinking water at the Donaldsonville and Geismar facilities are
unlikely because there are no private residences or public wells that derive drinking water supplies within 1,600
meters (1 mile) down-gradient of these facilities. However, ground-water releases are also likely at the third
active Louisiana plant (Uncle Sam), and potential exposures to contaminated ground water could occur at a
residence located 180 meters down-gradient from this facility.
Idaho. One of the two phosphoric acid plants in Idaho is discussed in a damage case in Section
12.3.2. Although this damage case does not provide conclusive evidence of long-term ground-water
contamination from releases of phosphogypsum and process wastewater, data presented indicate that a few
constituents of concern for these wastes (e.g., selenium, manganese, sulfate, and phosphate) may be
contaminating ground water down-gradient of the Caribou facility. Because of relatively high levels of
background contamination, a recent geophysical survey at Caribou did not delineate a ground-water
contamination plume originating at the plant Nevertheless, selenium concentrations exceed federal secondary
drinking water standards at on-site and down-gradient off-site production wells, and phosphate concentrations
at a down-gradient off-site production well exceed background levels by a factor of 170. Both of these
constituents are found in process wastewater, and a recent EPA site inspection report concludes that the
ground-water monitoring data "suggest that some leakage from the [process wastewater] cooling pond may be
occurring presently."9 In addition to this evidence of continuing contamination of the useable aquifer, the
Caribou damage case discusses a spill of process wastewater, resulting from a dike failure, that contaminated
off-site ground water with cadmium (at a concentration more than four times the federal drinking water
standard), phosphate, and fluoride. Consequently, EPA concludes that typical management of phosphogypsum
and process wastewater in Idaho may allow the continuous seepage of contaminants to ground water, and
mismanagement (i.e., spills) of process wastewater has caused ground-water contamination. Any ground-water
contamination that does occur as a result of waste management at the two Idaho facilities could pose human
health threats at residences located 240 and 850 meters down-gradient of the Caribou and Pocatello plants,
respectively.
North Florida and Mississippi. Although not demonstrated in the documented damage cases,
ground-water contamination potential also appears to be relatively high at the plants in North Florida and
Mississippi. As with the Central Florida facilities, the White Springs facility in North Florida is in karst
terrene (characterized by sinkholes and underground cavities developed by the dissolution of carbonate rock
such as limestone) which creates the potential for contaminant transport with limited dilution. Releases at
8 Louisiana Department of Environmental Quality. 1986. Letter from George H. Cramer, II, Administrator to Susan Stewart, Agnco
Manager Energy and Environmental Control, Re: Hydrogeologic Assessment, Final Report GD-093-0791.
9 EPA Region 10. 1988. Site Inspection Report to Nu-West Industries. Conda Plant, Caribou, Idaho. TDD F10-8702-08.
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Chapter 12: Phosphoric Acid Production 12-15
this plant could result in exposures at a residence located 180 meters down-gradient. Ground-water
contamination potential appears high at the Pascagoula plant in Mississippi because ground water occurs at
a depth of only 1.5 meters in this area. Human populations are not likely to be exposed to potential ground-
water contaminants at this facility, however, because currently there are no residences or public supply wells
within 1,600 meters down-gradient from the facility.
Texas and Wyoming. The potential for ground-water pathway risks at the Texas and Wyoming
facilities is relatively low. Releases from the management units at the plant in Pasadena, Texas are limited
to some extent because the stack at this facility is lined with recompacted local clay, and exposures to existing
populations are unlikely because there is no residence or public supply well within 1,600 meters down-gradient
from the facility. Similarly, the facility in Rock Springs, Wyoming poses a relatively low risk because its stack
has a synthetic liner and the nearest down-gradient residence is quite distant (greater than 1,600 meters).
Surface Water Release, Transport, and Exposure Potential
The potential for the release of contaminants from phosphogypsum stacks and process wastewater
ponds to surface water is also demonstrated by the damage cases presented in Section 12.3.2. These cases
indicate that phosphogypsum and process wastewater management at plants in Central Florida, North
Carolina, and Louisiana has resulted in the release of waste constituents to surface waters. Based on the
analysis of the damage case evidence, it is clear that management of phosphogypsum and process wastewater
in stacks and ponds can, and does, release contaminants to nearby surface waters. Depending on the distance
to surface waters, the hydrogeologic setting, and surface water use patterns, EPA concludes that there is a
potential for these released contaminants to migrate off-site and threaten human health via drinking water
exposures, threaten aquatic life, or render surface water resources unsuitable for potential consumptive uses.
In the following paragraphs, EPA presents a region-by-region assessment of the hazards to surface
water quality posed by phosphogypsum and process wastewater management For each region for which
surface water releases have been documented, the Agency first builds the case that releases from waste
management units have occurred in the past and are typical of current practices, then uses environmental
setting information to assess the potential hazards (i.e., health risks, risk to aquatic organisms, and resource
damage potential) at other facilities in the region. When no damage case information is available for a region,
evidence of release potential is used in conjunction with environmental setting information to assess the
hazards of potential releases from the plants in these regions.
Central Florida. The damage cases presented in Section 12.3.2 indicate that unpermitted discharges
of process wastewater and/or phosphogypsum stack seepage to surface waters have occurred at the Gardinier
and Seminole plants in Central Florida. At the Gardinier facility, a number of releases from 1984 to 1988
have been documented. Releases to surface water from solid waste management at this plant arise from the
discharge of untreated stack seepage from a drain system that is designed to intercept and collect leachate and
effluent flowing laterally away from the stack. As indicated in the damage cases, fluorides, phosphorus, and
radioactive substances are present at concentrations of concern in the effluent from this drain system. In
addition, these unpermitted discharges had a pH of 1.5 to 2.2. In 1988, county and state inspectors discovered
damaged vegetation on the shoreline of Hillsborough Bay along the west side of the gypsum stack where an
unpermitted discharge was occurring. The affected area - approximately one-half acre of saltwater marshes
and wax myrtle - had turned a brownish color,10 presumably as a result of the discharge of untreated stack
seepage. At the Seminole facility, surface water contamination has occurred via an unpermitted discharge to
Bear Branch. Similar releases, or releases of contaminated ground-water discharging to surface water, could
also occur at the eight other facilities in this area that are located near surface waters. At two of these
10 Hillsborough County Environmental Protection Commission. October 6, 1988. Memorandum from Roger Stewart, Director, to
Pam lorio, Commissioner.
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12-16 Chapter 12: Phosphoric Acid Production
facilities (i.e., Central Phosphates and IMC), the nearby river is used as a source of drinking water downstream
of the facility and releases to these rivers could pose a human health threat via drinking water exposures. Of
the 11 active Central Florida plants, only Royster/Mulberry is not within 1,000 meters of surface water and
is unlikely to pose a threat to surface water resources.
North Carolina. As at the Gardinier plant, unpermitted discharges of stack drainage and process
wastewater from the plant in Aurora, North Carolina are also associated with failure of the drain system
designed to collect seepage at the foot of the gypsum stacks. In two separate incidents in 1980 and one in
1987, concentrations of fluoride and phosphorus released from the plant exceeded permit limits as a result of
drainage ditch and dike failure and drain overflow. In the 1987 episode, the pH of a freshwater canal was
below 6.0 for two hours and 18 dead fish were discovered in the week following the release. Based on this
evidence, the Agency concludes that episodic releases from the phosphogypsum stack and ponds at this facility
were not adequately controlled by run-on/run-off controls and collection of stack seepage. In addition,
contaminants released to ground water may discharge to the Pamlico River and to the creeks in the vicinity
of the site where they may endanger aquatic life.
Louisiana. Two documented cases of surface water damages from phosphogypsum and process
wastewater management in Louisiana are presented in Section 12.3.2. At both the Donaldsonville and
Geismar plants, releases occurred as a result of the emergency discharge of untreated water from gypsum
stacks and ponds to surface waters. As noted in the damage cases, the facility operators claimed that these
discharges were necessitated by excess precipitation that threatened to cause stack failures. Emergency
discharges are permitted at facilities on the lower Mississippi during periods of excess precipitation. As
discussed above, ground-water contamination potential is also significant at the three facilities in Louisiana,
and ground water discharging to surface waters may provide another means of contaminant release. The
threats posed by releases to surface waters in Louisiana may be limited somewhat by the large flow of the
Mississippi River. Because the Mississippi River is not used as a source of drinking water directly downstream
of the three phosphoric plants, releases from these plants do not pose any current human health threats.
Based on the evidence presented above, EPA concludes that constituents of phosphogypsum and
process wastewater that are managed near surface water bodies are likely to be released to nearby surface
waters as a result of stack failures, drain failure, and possibly ground-water seepage. The facilities in Pasadena,
Texas; Pascagoula, Mississippi; and White Springs, Florida (north) are located close to surface waters and
receive relatively large quantities of precipitation. Consequently, these plants may present a hazard to surface
water similar to that of the Louisiana and Central Florida facilities. The surface water contamination potential
at the plant in Pocatello, Idaho is somewhat lower because the small amount of precipitation limits ground-
water recharge and the possibility of stack failure due to excess precipitation, but contamination of the
Portneuf River (located only 240 meters away) may occur. Surface water contamination is unlikely at the
plants in Rock Springs, Wyoming and Caribou, Idaho because of the relatively small amounts of annual
precipitation (i.e., 20 to 35 cm/year) and the large distances to the nearest surface water (370 to 2,600 meters).
Air Release, Transport, and Exposure Potential
Air pathway hazards associated with phosphogypsum and process wastewater relate primarily to the
emission of radon gas from the radioactive decay of radium found in these wastes and the emission of
paniculate matter resulting from the disturbance of the phosphogypsum stack surface.
In support of a rulemaking on national emission standards for radionuclides, ERA'S Office of Air and
Radiation (OAR) has assessed the risks of radon emissions from phosphogypsum stacks.11 In this risk
11 U.S. EPA. 1989, Risk Assessments: Environmental Impact Statement for NESHAPS Radionuclides, Volume 2 (Background
Information Document), Office of Radiation Programs.
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Chapter 12: Phosphoric Acid Production 12-17
assessment, OAR estimates that the lifetime cancer risk to the maximally exposed individual (MEI) caused
by the inhalation of radon in the vicinity of a phosphogypsum stack is 9xlO~5. The MEI lifetime cancer risk
from radon inhalation is greater than or equal to IxlO"5 at 17 of the 21 active phosphoric acid facilities. Only
the plants in Pascagoula, Mississippi; Aurora, North Carolina; Rock Springs, Wyoming; and White Springs,
Florida have an estimated MEI lifetime cancer risk from radon inhalation of less than IxlO"5.
Because phosphogypsum forms a crust on inactive areas of the stack as it dries, and because the active
areas of the stack are moist, the emission of paniculate matter by wind erosion is not thought to be a
significant release mechanism.12 Physical disturbance of dried phosphogypsum (e.g., by vehicles driving over
the stacks), however, may be an important particle release mechanism. The OAR risk assessment estimated
that the lifetime cancer risks from radionuclides in particle emissions from stacks range from SxlO"8 to ZxlO"6.
Based on these risk estimates, the OAR assessment concludes that the risk from inhaling radon emitted from
phosphogypsum stacks is approximately two orders of magnitude greater than the cancer risk posed by the
inhalation of fugitive dust from phosphogypsum stacks.
The OAR study did not investigate the cancer risk posed by other toxic constituents (i.e., arsenic and
chromium) in phosphogypsum via particle inhalation. To supplement OAR's radiological assessment, EPA
performed a screening level analysis of the risks posed by arsenic and chromium blown from phosphogypsum
stacks. Using typical concentrations of arsenic and chromium in phosphogypsum, EPA calculated a lifetime
cancer risk of 7xlO"7 from exposure to these constituents in windblown phosphogypsum.13 This analysis
shows that the risk posed by arsenic and chromium in inhaled phosphogypsum particles is on the order of 35
percent of the risk posed by radionuclides in inhaled particles.
Based on the these findings, the Agency concludes that phosphogypsum stacks pose a considerable
air pathway cancer risk primarily as a result of radon emissions from the stacks. By summing the risk
estimates for radon inhalation, radionuclides in phosphogypsum particles, and arsenic and chromium in
particles, EPA estimates a total air pathway lifetime MEI cancer risk of approximately 9xlO"5 from exposure
to phosphogypsum constituents. This risk is primarily from inhalation of radon emitted from stacks (9xlO~5)
with minor contributions from the inhalation of phosphogypsum particles containing radionuclides (2x10"*)
and arsenic and chromium (7xlO"7). Based on the OAR estimates of risk from radon emitted from the stacks,
the following plants appear to pose the greatest air pathway risks: Pasadena, Texas; Royster/Palmetto; Uncle
Sam, Louisiana; Seminole; Central Phosphate; and Caribou, Idaho. As mentioned above, the stacks at
Pascagoula, Mississippi; Aurora, North Carolina; Rock Springs, Wyoming; and White Springs, Florida pose
lower MEI lifetime cancer risk (i.e., < IxlO"5).
Proximity to Sensitive Environments
Eighteen of the 21 active U.S. phosphoric acid plants are located in or near environments that are
vulnerable to contaminant release or that have high resource value. In particular:
• The Seminole facility reported in its response to the National Survey on Solid Wastes
from Mineral Processing Facilities that it is located in an endangered species habitat.
• The Royster/Palmetto and Pascagoula facilities are located within 6.5 and 7.8 miles,
respectively, of the critical habitat of an endangered species. The two endangered
species are the Florida Manatee and the Mississippi Sandhill Crane. Because of the
u Ibid, p. 13-Z
13 This risk estimate is based on a comparison of the dust inhalation risks posed by (1) median arsenic and chromium concentrations
as determined by EPA's data base developed for this study and (2) average concentrations of radium-226, uranium-234, uranium-238,
thorium-230, polomum-210, and lead-210 presented in the OAR analysis. To calculate the relative risks posed by these constituent
concentrations, EPA assumed an exposure point concentration of windblown phosphogypsum in air, and applied standard cancer slope
factors and exposure assumptions, such as those used in developing the screening criteria (see Section 2.2.2), to estimate the relative
contributions of carcinogenic metals and radionuclides to the inhalation risks posed by airborne phosphosypsum.
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12-18 Chapter 12: Phosphoric Acid Production
relatively large distance to these protected areas, the potential for impacts on the
species or their critical habitat is quite low.
• Eight plants (i.e., Geismar, CF Chemicals, Gardinier, Pocatello, Pasadena, Pascagoula,
Seminole, and Aurora) are located in 100-year floodplains. Management of wastes in
floodplains creates the potential for large, episodic releases caused by flood events.
(The effectiveness of flood control structures at these plants is not known.)
• The Gardinier, Pascagoula, and Aurora plants are located in a wetland (defined here to
include swamps, marshes, bogs, and other similar areas). The Agrico/Mulberry,
Geismar, Central Phosphates, CF Chemicals, Conserv, Royster/Palmetto, Farmland, Fort
Meade, IMC, Caribou, White Springs, Royster/Mulberry, and Seminole plants are
located within one mile of a wetland. Wetlands are commonly entitled to special
protection because they provide habitats for many forms of wildlife, purify natural water,
provide flood and storm damage protection, and afford a number of other benefits.
Although the location of wetlands relative to potential contaminant sources is unknown,
if contaminants released to surface water and ground water migrate to wetlands, the
water quality degradation may adversely affect the wetland.
• The Pocatello facility is located in a fault zone. Wastes managed in a fault zone may
be subject to episodic releases due to earthquake-induced failure of containment systems
or berms.
• The Central Phosphates and Royster/Palmetto facilities are located in an area of karst
terrain characterized by sinkholes and underground cavities developed by the dissolution
of carbonate rock. Solution cavities that may exist in the bedrock at this site could
permit any ground-water contamination originating from the wastes to migrate in a
largely unattenuated and undiluted fashion.
Risk Modeling
Based upon the evaluation of intrinsic hazard and the descriptive analysis of factors that influence risk
presented above, EPA has concluded that the potential for phosphogypsum and process wastewater from
phosphoric acid production to impose risk to human health or the environment is significant, if managed
according to current practice. As discussed above,
• Phosphogypsum and phosphoric acid process wastewater contain a number of
constituents at concentrations that exceed conservative screening criteria, phosphogyp-
sum occasionally contains chromium concentrations in excess of the EP toxicity
regulatory level, and process wastewater regularly exhibits the RCRA hazardous waste
criterion for corrosrvity (i.e., pH below 2.0) and exceeds EP regulatory levels for
cadmium, chromium, and selenium.
• Ground-water contamination from phosphogypsum stacks and process wastewater ponds
has occurred or is likely at almost all plants, and, at some sites, contamination has
reached off-site wells at levels above drinking water standards.
• Episodic and continuous releases of pond and phosphogypsum stack waters to surface
water occur at a number of plants, and aquatic organisms have been adversely affected
by these releases.
• Radon emissions from phosphogypsum stacks and windblown phosphogypsum particles
are estimated to present a lifetime cancer risk to maximally exposed individuals of
almost IxlO"4.
Because of the weight of the empirical and analytical evidence summarized above, the Agency did not conduct
a quantitative risk modeling exercise addressing these wastes. Section 12.3.3 provides a more detailed
discussion of the Agency's conclusion that current management of phosphogypsum and phosphoric acid process
wastewater poses a significant hazard.
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Chapter 12: Phosphoric Acid Production 12-19
12.3.2 Damage Cases
EPA conducted waste management case studies to assess the impacts of phosphogypsum and process
wastewater management practices on human health and the environment. This review included 21 active and
eight inactive phosphoric acid facilities. The inactive facilities are: Agrico, Hahnville, LA; Agrico, Fort
Madison, IA; Albright & Wilson, Fernald, OH; JR Simplot, Helm, CA; Mobil Mining & Minerals, De Pue,
IL; U.S. Agri-Chemicals Corp., Bartow, FL; Waterway Terminals, Helena, AR; and MS-Chemical located in
Pascagoula, Mississippi. Documented damages attributable to management of phosphogypsum or process
wastewater have been documented at more than ten facilities. Selected facilities are discussed in detail below.
Several factors play an important role in influencing the effectiveness of typical phosphogypsum and
process wastewater management practices. Among these are water balance and soil stability. In Florida, for
example, phosphogypsum dewatering and reduction of wastewater volumes are made possible due to the
climate, specifically the relative amounts of precipitation and evaporation, in this region. In other areas,
however, such as Louisiana, a net precipitation surplus necessitates a system dependent on planned discharges
to surface waters. Soil stability appears to be much greater in Florida as well, where gypsum may be stacked
to heights up to 60 meters (200 feet). In Louisiana, gypsum piles over 12 meters in height are generally
considered unstable. In light of these differences, the case studies presented in this section are grouped by
state.
Idaho
Nu-West Industries-Conda, Soda Springs, Idaho
The Nu-West plant is located approximately five miles north of Soda Springs, Idaho, near the
abandoned mining town of Conda. The site covers approximately 650 hectares (1,600 acres). With the
exception of a period from 1985 to 1987, the plant has been in operation since 1964.
Currently, Nu-West formulates and markets phosphate-based chemicals and fertilizers. The
phosphogypsum waste is a by-product of the digester system, which produces ortho-phosphoric acid (P2O5)
from phosphate ore. Gypsum is slurried with process water and pumped to two storage ponds on top of the
gypsum stacks, which have been in use since 1964 and presently cover approximately 240 to 280 hectares (600
to 700 acres). The gypsum ponds are unlined; the stacks are about 46 meters (150 feet) above the natural
ground surface. Drainage systems decant slurry water off the top of the higher ponds into ponds at lower
elevations.
During March 1976, a dike surrounding the Nu-West cooling pond failed and released 400 acre feet
of wastewater into the surrounding area. The water spread out and ponded on an estimated 20 to 40 hectares
(50 to 100 acres) of farm land. The water then migrated via a natural drainage path, forming a small river that
extended four miles to the south. Wastewater reportedly infiltrated into local soil and underlying bedrock
along its overland migration path, but never entered a natural surface water body.
While the Idaho Division of Environment determined that dilution during spring run-off reduced
surface concentrations of contaminants to within acceptable limits, the Caribou County Health Department
recorded significant increases in ground-water concentrations of phosphate, cadmium, and fluoride immediately
following the spill. Samples from a J.R. Simplot Company (Conda Operation) production well No. 10, located
down-gradient from the Nu-West facility, show that before the spill occurred, levels of phosphate in the ground
water averaged 100 mg/L, and rose to 1,458 mg/L after the spill. Levels of cadmium in the ground water
averaged 0.01 mg/L before the spill and 0.239 mg/L after the spill, and levels of fluoride averaged 5 mg/L
before, and 39 mg/L after, the spill, respectively.14
14 EPA Region 10. 1988. Site Inspection Report to Nu-West Industries Conda Plant, Caribou, Idaho. TDD F10-8702-08.
March, 1988.
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12-20 Chapter 12: Phosphoric Acid Production
In 1987, EPA Region X conducted a file review and site inspection of Nu-West. This inspection
included ground-water sampling, aqueous and solid sampling from the waste ponds, and a geophysical survey.
A total of six ground-water samples were collected: two from on-site industrial production wells (MF well,
P.W. No. 1); two off-site industrial production wells (Simplot No. 11, Simplot No. 10); and, two domestic wells
in the site area. Results of the Nu-West site inspection were published in a site inspection report in March,
1988. Selenium exceeded Federal Primary Drinking Water Standards in all of the production well samples.
Manganese and sulfate exceeded Federal Secondary Drinking Water Standards in Simplot Well No. 10.
Phosphate was detected at 8.2 mg/L in Simplot Well No. 10, a level approximately 30 times greater than that
found in the MF well and 170 times greater than that found in the background well (Simplot Well No. 11).
A total of eleven target compound list (TCL) inorganic elements were detected in at least one of the domestic
well samples; however, none of the sample concentrations exceeded Federal Primary or Secondary Drinking
Water Standards.15
The geophysical survey results indicated that there was no significant difference between the
background and on-site values obtained from the survey. However, as stated in the EPA Site Inspection
Report: "There are seven registered domestic wells within a three mile radius of the Nu-West site, serving
an estimated 27 people. Total depths of these wells range between 90 feet to 245 feet below ground surface.
Eleven registered industrial production wells exist on and near the Nu-West site, one of which provides
drinking water for approximately 45 J.R. Simplot employees in Conda (Simplot #11). At the time of the
[EPA] inspection, Nu-West employees consumed bottled water due to poor water quality of the only well in
use at the site (MF well)."16
The EPA Site Inspection Report concludes by stating: "Levels of TCL inorganic elements and anions
detected in the groundwater samples during the [EPA] site investigation were similar to those obtained by the
Caribou County Health Department during non-spill event time periods. However, the levels detected during
the [EPA] site investigation should not be considered indicative of stable long-term groundwater quality
conditions at the site. [Data show] that significant increases in groundwater contaminant concentrations have
occurred as a result of a past spill at the Nu-West facility. Although survey results are inconclusive, the data
suggest that some leakage from the cooling pond maybe occurring presently. If leakage from the cooling pond
increases as a result of pond aging or increased water circulation, a contaminant plume may develop and
migrate to the south-southwest."17
Florida
Gardinier, Inc., in East Tampa, Florida
Gardinier, Inc's East Tampa Chemical Plant Complex encompasses about 2,600 acres of land and is
located in west-central Hillsborough County, Florida. The facility is located at the mouth of the Alafia River
adjacent to Hillsborough Bay. The plant began its operations in 1924 and has been expanded several times
by various owners. In 1973, Gardinier, Inc. took over the entire operation. Gardinier, Inc. is owned by Cargill,
Inc. of Minneapolis, Minnesota. Operations currently include production of phosphoric acid and phosphate
and other fertilizers.18-19
u Ibid.
16 EPA Region 10. 1988. Site Inspection Report to Nu-West Industries Conda Plant, Caribou, Idaho. TDD F10-8702-08.
March, 1988.
17
Ibid.
18 Ardaman & Associates, Inc. September 23,1983. Groundwater Monitoring Plan for East Tampa Chemical Plant Complex,
Hillsborough County, Florida.
Ibid.
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Chapter 12: Phosphoric Acid Production 12-21
Gardinier's on-site waste management units include two process water ponds (Nos. 1 and 2) and a
gypsum stack. Process Water Pond No. 1 is an unlined pond that occupies 13 hectares (32 acres) and is 2
meters (6 feet deep); Process Pond No. 2 occupies 80 hectares and is 2.1 meters deep. The gypsum stack,
which as of December 31,1988 contained about 58 cubic meters (76 million cubic yards) of material, occupies
an area of 150 hectares and is 61 meters high. The ponds on top of the gypsum stack occupy 16 hectares and
are 2 meters deep. The typical pH of the liquid in the gypsum stack ponds is I.8.20
Phosphogypsum is piped to the gypsum stack as a slurry mixture (approximately 30 percent solids).
The gypsum settles from the slurry and the liquid is decanted for reuse in the manufacturing process. Water
which seeps through the stack is collected in a perimeter drain that is buried at the toe of the stack. The drain
carries the seepage water to a sump in the northeast corner of the gypsum stack where it is pumped to an
evaporation pond located on part of the gypsum stack. Surface water run-off from the exterior slopes of the
stack is discharged into Hillsborough Bay.21
Records at the Hillsborough County Environmental Protection Commission (HCEPC) cite
environmental incidents at the Gardinier facility as far back as November 21,1973, when HCEPC investigated
a citizen's complaint and discovered 210 dead crabs in traps placed near the facility's northwest outfall. The
pH of the outfall water was 19.22'23
Water quality violations attributable to Gardinier resulted in the following administrative actions: a
Consent Order negotiated between the HCEPC and Gardinier on August 22, 1977; a Citation to Cease
Violation and Order to Correct from HCPEC on November 8, 1984; a Warning Notice from the State of
Florida Department of Environmental Regulation (FDER) on April 9,1987; a Citation to Cease and Notice
to Correct Violation from the HCEPC on May 26,1988; and, a Warning Notice from FDER on October 18,
1988. These administrative actions were issued to Gardinier following unpermitted discharges from either the
gypsum stack or the cooling water ponds.
The November 8, 1984 citation was issued for an untreated effluent discharge which occurred on
October 8,1984. The citation notes that "toe-drain effluent contains several thousand milligrams per liter of
fluorides and phosphorus and up to 150 pico-curries per liter of radioactive substances. Also, its pH can be
as low as 1.5 standard units."24 A sample of the discharge on March 30, 1987, which resulted in the April 9,
1987 warning notice, shows that the pH was 1.9, total phosphorus was 6,740 mg/L and dissolved fluorides was
4,375 mg/L.25 HCEPC analyzed a sample of the discharge which resulted in the October 18, 1988 warning
notice and reported the following results: pH, 2.2; total phosphorus, >4,418 mg/L; and fluoride,
1,690 mg/L.26
The May 26,1988 citation from HCEPC states that "available agency records indicate a considerable
history of incidents of discharge resulting in exceedances of environmental standards and contamination of the
air and waters of Hillsborough County. Enforcement in each case required remedial actions intended to
20 Gardinier, Inc. March 29,1989. National Survey of Solid Wastes from Mineral Processing Facilities.
21 Ardaman & Associates, Inc. September 23,1963. Groundwater Monitoring Plan for East Tampa Chemical Plant Complex,
Hillsborough County, Florida.
22 Hillsborough County Environmental Protection Commission. May 6,1988. Gardinier History.
23 Hillsborougb County Environmental Protection Commission. November 26,1973. Interoffice Memo from Robert M. Powell to
Richard Wilkins.
24 Hillsborough County Environmental Protection Commission. November 8,1984. Citation to Cease Violation and Order to
Correct issued to Gardinier, Inc.
25 Hilbborough County Environmental Protection Commission. March 31,1987. Notice of Alleged Violation issued to Gardinier.
Inc.
26 Florida Department of Environmental Regulation. October 18,1988. Warning Notice No. WN88-OOOirW29SWD issued to
Gardinier, Inc.
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12-22 Chapter 12: Phosphoric Acid Production
correct the effects of the discharge where appropriate, as well as design and maintenance measures to prevent
reoccurrence of the same or like incident. Despite all efforts, such incidents continue to occur."27
HCEPC records also include a Gardinier Air Complaints Summary which lists 78 citizen complaints
about the facility from December 6,1983 to May 10, 1988. The complaints were made about noxious odors,
fumes, smoke, dust or mist from the facility. One of the complaints clearly identifies the gypsum stack as the
source; the relationship of the other complaints to gypsum and water management systems at the facility
cannot be determined from the available documentation. HCEPC responded to most of these complaints with
a phone call or site visit. At least three of the site visits resulted in HCEPC issuing a warning notice to the
facility.28
Since 1985, Gardinier has monitored ambient air quality for radon and fluoride. In 1985, Gardinier
reported its average radon-222 flux from the gypsum pile to be 21.6 pCi/square meter-second (the recently
promulgated NESHAP specifies a limit of 20 pCi/m2-sec). Ambient fluoride was 0.43 ppb, with a maximum
reading of 1.2 ppb.29 Nonetheless, Gardinier reported that no National Ambient Air Quality Standards or
National Emissions Standards for Hazardous Air Pollutants were exceeded during 1988.30
In addition to the impacts to surface water, biota, and air noted above, ground water at the facility
has been affected by facility operations. Ground-water quality has been monitored quarterly at the facility for
several years. Since January 1,1984, standards for the following drinking water parameters were exceeded in
wells located both up-gradient and down-gradient of the facility's special waste management units: chromium,
radium-226 and radium-228, gross alpha, chloride, iron, manganese, pH, and total dissolved solids.31
Examination of data for the period 1987 through early 1989 indicates that several on-site wells in the shallow
aquifer routinely exceeded the gross alpha primary drinking water standard by a factor of between 2 and 4;
exceedances in the intermediate aquifer were also common, although less frequent and of lesser magnitude.
Central Phosphates, Plant City, Florida
The Central Phosphates, Inc. (CPI) Plant City Chemical Complex is located approximately 16 km (10
miles) north of Plant City. The facility occupies approximately 616 hectares (1,520 acres) of land.32 The
site is underlain by a surficial aquifer and the Floridan aquifer. The surficial aquifer ranges in depth from .3
to 15 meters (one to 50 feet) and is recharged by local rainfall.33 In the Floridan aquifer, the uppermost
useable aquifer at the site, wells are generally cased to depths greater than 200 feet.34 The principal us"-s
of the water in the uppermost useable aquifers underlying the site are rural domestic, agricultural, and
commercial/ industrial.35
27 Hillsborough County Environmental Protection Commission. May 26, 1988. Case No. 6169 WP. Citation to Cease and
Notice to Correct Violation issued to Gardinier, Inc.
28 Hillsborough County Environmental Protection Commission. Undated. Gardinier Air Complaints Summary.
29 Gardinier, Inc. September 25,1985. First Annual Report submitted to the Hillsborough County Administrator pursuant to
Development Order 80-713.
30 Gardinier, Inc. March 29,1989. "National Survey of Solid Wastes from Mineral Processing Facilities."
31 Ibjd.
32 Ardaman & Associates, Inc., April 2,1987, Geotechnical Evaluation and Design Recommendations for Proposed Gypsum Stack
Expansion, Plant City Chemical Complex, Hillsborough County, Florida (part).
33 Central Phosphates, tax, March 29,1989, "National Survey on Solid Wastes from Mineral Processing Facilities."
34 Ardaman & Associates, Inc., August 9,1988, Contamination Assessment Report, Central Phosphates, Inc., Plant City
Phosphate Complex, Hillsborough County, Florida.
35 Central Phosphates, Inc., March 29,1989, "National Survey on Solid Wastes from Mineral Processing Facilities."
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Chapter 12: Phosphoric Acid Production 12-23
The CPI plant began operation in December 1965; principal products include phosphate fertilizer,
sulfuric acid, and ammonia.36 Phosphogypsum generated during the production of phosphoric acid is
disposed onsite at the company's 170 hectare (410-acre) phosphogypsum stack. A 50 hectare unlined process
water cooling pond completely surrounds the gypsum stack. The depth of the cooling pond is 2.4 meters (8
feet). As of December 31, 1988, the unlined gypsum stack was 111 feet high and contained approximately
70,000,000 tons of material. The top of the gypsum stack presently contains 8 ponding areas occupying a total
area of approximately 105 hectares. Two designated areas on top of the stack, located in the middle, are used
for disposal of non-hazardous waste materials, such as construction and demolition debris and non-hazardous
chemicals.37
Activities at the Central Phosphates site have resulted in ground-water contamination in the surficial
and upper Floridan aquifers. To date, it has been determined that the surficial aquifer and, to an
undetermined extent, the Floridan aquifer have increased levels of fluoride, sodium, gross alpha radiation,
heavy metals, sulfate, total dissolved solids, and nutrient compounds in excess of applicable guidance
concentrations and/or state and federal drinking water standards. Contaminated ground water, primarily in
the surficial aquifer, has migrated off-site under approximately 11 hectares (27.5 acres) of the Cone Ranch
property, located south of the CPI facility.38'39
Quarterly ground-water sampling began at the Central Phosphates facility in April 1985. Based on
the results of sampling from these wells in the second quarter of 1985, a warning notice was issued to the
facility by the Florida Department of Environmental Regulation (DER) for violation of the primary drinking
water regulations. Maximum contamination levels for sodium and chromium were exceeded in a down-
gradient well in the Floridan aquifer and for sodium, chromium, and fluoride in a down-gradient well in the
surficial aquifer.40
In June 1987 the West Coast Water Supply Authority provided DER with preliminary data from
laboratory analysis of ground-water samples collected from the Cone Ranch property which indicated
degradation of both the surficial and the upper Floridan aquifers.41
The final report on ground-water investigations conducted at Cone Ranch during May and June 1987,
prepared by consultants to the West Coast Regional Water Supply Authority, identifies two areas of
contamination on the Cone Ranch property. The report concludes that contamination in one area (designated
Area A) was caused by a dike failure and resultant spill of process water from the Central Phosphates facility
in 1969 and that contamination in another area (Area B) was caused by seepage of contaminated water from
the recirculation pond located immediately north of the spill area.42
A consent order addressing the ground-water contamination problems at the site was drafted by DER
during July of 1987 and signed by DER and Central Phosphates, Inc. on September 29, 1987. The consent
order documents violations of primary and secondary drinking water standards for chromium, sodium, fluoride,
gross alpha radiation, lead, and cadmium from a down-gradient well in the surficial aquifer. These violations
occurred from May 6, 1985 through April 27, 1987; maximum values listed in the consent order for each
36 Ardaman & Associates, Inc., September 21, 1987, Quality Assurance Project Plan, Central Phosphates, Inc., Plant City
Phosphate Complex (pan).
37 Central Phosphates, Inc., March 29,1989, "National Survey on Solid Wastes bom Mineral Processing Facilities."
38 West Coast Regional Water Supply Authority. May 11,1989. Letter from M. G. Korosy, Hydrologic Services Manager, to M.
Troyer, ICF, Inc.
39 Ardaman & Associates, Inc., August 9,1988, Contamination Assessment Report, Central Phosphates, Inc., Plant City
Phosphate Complex, Hillsborough County, Florida.
40 State of Florida, Department of Environmental Regulation, Warning Notice No. 29-85-07-182, Jury 17,1985.
41 Case Chronology for Central Phosphates, Inc., undated, Florida Department of Environmental Regulation enforcement files.
42 Leggette, Brashears & Graham, Inc., July 15, 1987, West Coast Regional Water Supply Authority Hydrologic and Water
Quality Site Investigation at Cone Ranch, Hillsborough County, Florida.
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12-24 Chapter 12: Phosphoric Acid Production
contaminant are as follows: chromium, 0.075 mg/L; sodium, 1700 mg/L; fluoride, 6 mg/L; gross alpha, 29
pCi/L; lead, 0.11 mg/L; and, cadmium, 0,022 mg/L. -The consent order required Central Phosphates, Inc. to
implement corrective measures and ground-water remediation at the site.43
The Joint Water Quality/RCRA Overview Committee of the Florida Phosphate Council has recorded
quarterly sampling data from the Central Phosphates, Inc. site from April 24, 1985 through January 18,1989
for DER Well Nos. 1 through 6, as well as data from sampling in April 1988 for miscellaneous other wells
located both on and off CPI property. These data show consistent exceedances of water quality standards in
the down-gradient surficial aquifer for pH, iron, Quoride, manganese, total dissolved solids, and sulfate. Water
quality standards for iron and total dissolved solids were consistently exceeded in the down-gradient upper
Floridan aquifer.44
The Contamination Assessment Report (CAR) for the CPI facility, prepared pursuant to the Consent
Order, concurs with the assessment made by the West Coast Regional Water Quality Authority in its definition
of two plumes of contaminated ground water which have migrated offsite. Area A was found to comprise an
area of 6.3 hectares (15.5 acres) in the surficial aquifer and 2.4 hectares in the upper Floridan aquifer. The
off-site areal plume within the surficial aquifer was found to extend approximately 150 meters (500 feet) south
and 460 meters east of the CPI property. The plume in the surficial aquifer of Area B was found to extend
approximately 150 meters south in the Cone Ranch property, covering an area approximately 5 hectares.45
Phase II of CPI's contamination assessment, due for completion in the near future, is to include definition of
the lateral and vertical extent of contamination.46
Sem/no/e Fertilizer, In Barrow, Florida
The Seminole Fertilizer Corporation (formerly W.R. Grace & Company) Bartow Chemical Plant is
located in central Polk County between the towns of Bartow and Mulberry. The plant began operation in
1954, and includes production facilities for phosphoric acid and phosphate and other fertilizers. The facility
is underlain with three aquifers. The depth of the surficial aquifer ranges from 3 to 18 meters (10 to 60 ft).
The intermediate aquifer ranges in depth from 18 to 61 meters. The typical depth at the facility to the
uppermost useable aquifer (the Floridan) is approximately 61 meters.47
Waste management facilities at Seminole include one wastewater treatment plant, nine surface
impoundments, two landfills, and two phosphogypsum stacks. The wastewater treatment plant, which is a two-
stage liming facility, is used only during unusually intense rainfall events. Two surface impoundments are
associated with the wastewater treatment plant: surface impoundment No. 1 is the primary liming pond and
surface impoundment No. 2 is the secondary pond. Surface impoundment No. 3 occupies approximately 1.3
million square feet and is used as a cooling pond for process wastewaters, while surface impoundments Nos.
4-6 are a series of interconnected cooling ponds. The pH of the process water in the cooling ponds varies
from 1.8 to 2.3, due to seasonal rains. Surface impoundments Nos. 7-9 are old clay settling ponds. Of the
facility's two landfills, only one is currently in use. Landfill No. 1, occupying approximately 11 hectares (28
acres), is closed. Landfill No. 2 occupies 5 hectares and is used for filter cloths and solid materials not
pumped to the gypsum stack.48
43 Consent Order, September 29,1987, between the Sute of Florida Department of Environmental Regulation and Central
Phosphates, Inc.
44 Florida Phosphate Council, Joint Water Quality/RCRA Overview Committee, 1989, Groundwater Sampling Data.
45 Andaman & Associates, Inc., August 9,1988, Contamination Assessment Report, Central Phosphates, Inc., Plant City
Phosphate Complex, Hillsborough County, Florida.
46 West Coast Regional Water, Supply Authority. 1990. Letter from M. Koroty to P. Bill, ICF, Re Cane Beach Property,
Hillsborough County, Florida; Draft Mineral Processing Waste Management Case Study on Central Phosphates, Inc., May 23.
47 Seminole Fertilizer Corporation. March 27,1989. "National Survey on Solid Wastes from Mineral Processing Facilities."
48 Ibid.
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Chapter 12: Phosphoric Acid Production 12-25
The north gypsum stack, which first received waste in 1954, occupies approximately 65 hectares (159
acres) at an average height of 9 meters (28 ft). This stack receives process wastewater, phosphogypsum,
gypsum solids from "tank clean out," and filter cloths. As of December 31, 1988, the north gypsum stack
contained 14 million short tons of material. The south gypsum stack, which first received waste in 1965,
occupies approximately 164 hectares at an average height of 14 meters. As of December 31, 1988, the south
gypsum stack had accumulated 38 million metric tons of material.49
Activities at the Seminole Fertilizer Corporation facility have resulted in elevated levels of several
parameters in ground water in the surficial and intermediate aquifers. This contamination has affected potable
water wells in the area, some of which have been replaced with water from the City of Bartow's public
supply.50
Seminole maintains eight monitoring wells as part of the ground-water monitoring system required
for its state permit. Seminole has stated that MW-3 and MW-7 are up-gradient, background wells. All other
wells are listed as down-gradient. The facility's ground-water data from September 1986 through March 1989
show that the down-gradient wells repeatedly exceeded the water quality standards for pH, gross alpha
radiation, radium-226 and radium-228, iron, manganese, TDS, sulfate, cadmium, chromium, lead, and
fluoride.51
On March 8,1988, the Florida DER issued a warning notice to W.R. Grace & Company for violations
of its ground-water monitoring permit during the third and fourth quarters of 1987. The standards for gross
alpha radiation, radium-226 and radium-228, and sodium had been exceeded in some ground-water samples.52
The analytical results showed the following maximum concentrations for each parameter: gross alpha, 107
pCi/L; radium-226 & -228, 14.4 pCi/L; and, sodium, 657 mg/L.
In addition to on-site wells, neighboring potable water wells have also been adversely affected.
Analytical data from May 1988 show that 12 of 18 wells contained at least one contaminant at levels above
the drinking water standards. Contaminants that were found in the samples included arsenic, lead, sodium,
gross alpha, radium-226 and radium-228, iron, pH, sulfate, and total dissolved solids.53 Potable water wells
near the facility were replaced by a public water supply from the City of Bartow; W.R. Grace apparently paid
for the water supply line installation and connection to the affected water users.54
Seminole has also received a warning notice from the Florida DER for an unpermitted discharge of
process water from the facility to Bear Branch.55
Florida - Other
Management histories similar to those described for the above Florida facilities have also been
documented by the Florida DER for CF Chemicals, Inc. and Farmland Industries, Inc. in Bartow, FL, and for
Conserv, Inc. in Nichols, FL.
* Ibid-
50 Florida Department of Environmental Regulation. September 29,1988. Conversation Record between B. Barker, Drinking Water
Section, and K_ Johnson, FDER.
51 Seminole Fertilizer Corporation. June 1,1989. Copy of facility's ground-water monitoring data from 9166 to 3/89.
52 Florida Department of Environmental Regulation. March 8,1988. Warning Notice No. 53-88-03-061.
53 W.R. Grace & Company. June 3,1988. Letter from Glenn Hall, Environmental Engineer, W.R. Grace & Co., to Kirk
Johnson, Florida Department of Environmental Regulation and ground-water monitoring data for private potable wells adjacent to the
facility.
M Florida Department of Environmental Regulation. September 29,1988. Conversation Record between Bob Barker, Drinking
Water Section, and Kirk Johnson, FDER.
55 Florida Department of Environmental Regulation. May 30, 1984. Warning Notice No. 53-84-05-327.
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12-26 Chapter 12: Phosphoric Acid Production
North Carolina
Texasgutf Chemicals, in Aurora, North Carolina
Texasgulf s phosphate plant is located six miles north of Aurora, Beaufort County, North Carolina,
near the Pamlico River. Since at least 1973, Texasgulf Chemicals Company, an unincorporated division of
Tfexasgulf, Inc., has engaged in the production of calcined and dried phosphate rock, sulfuric acid, phosphoric
and superphosphoric acid, and other phosphate fertilizer ingredients at the Aurora plant.56
Waste management units include clay slurry settling ponds, two unlined cooling water ponds, gypsum
stacks, and clay blend piles, which contain a mixture of clay and gypsum.
The process of purifying the ore involves the separation of very fine clay particles from the phosphate
rock. The clays leave the separation process as a water based slurry that is referred to as "slimes." They are
hydraulically transferred to settling ponds where the clear water fraction is separated and discharged. There
are 5 settling ponds with discharges to South, Bond, and Long Creeks via 12 permitted outlets.57
Two cooling water ponds are used to recirculate process water through the phosphoric acid and
fertilizer manufacturing areas, where it is primarily used in acid dilution, cooling, gypsum slurrying, and
operation of emission control devices. Pond No. 1, with a surface area of 49 hectares (120 acres), began
operation in November 1966. Pond No. 2, with a surface area of 24 hectares, began operation in late 1973.58
There are six gypsum stacks or piles located on the plant site. The stacks, which cover approximately
101 hectares, are surrounded by a ditch that returns excess water from the stacks to Pond No. 1. There are
also a number of gypsum-clay blend piles (designated R-l, R-2, R-4, and R-5) on the site which are/were used
in land reclamation activities.
The North Carolina Department of Environmental Management has recorded a number of incidents
dating back to 1980 at the Texasgutf Chemicals Plant which may have resulted in negative environmental
impact.59 These incidents include violations of Texasgulf s effluent permit and spills from the facility. For
example, violations of the effluent permit for daily maximum phosphorus and fluoride were recorded in 1980
on March 12, March 13, December 9, and December 11. Daily maximum permit limits are 9 mg/L for
phosphorus and 10 mg/L for fluoride. Recorded concentrations for the four days ranged from 11 to 34 mg/L
for phosphorus. Fluoride concentrations were 12 mg/L on March 12 and March 13. These violations occurred
when contaminated wastewater from the toe ditch of the gypsum pile overflowed into the company's fresh
water system. A spill of 150,000 cubic meters (40 million gallons) of gypsum stack decant water into a nearby
fresh water canal occurred on January 4,1987 when a retaining dike around one of the gypsum stacks failed.
A 24-hour analysis of the canal water showed a pH drop to a low of 4.2, with a two-hour period when pH was
below 6.0. At least 18 dead fish were counted along the canal60 The company was fined $1,000 for the
incident by the State of North Carolina.61
* NC-Eiwironmental Management Commission (EMC). April 2,1967. Findings and Decision and Civil Penalty Assessment.
57 NC-DivisioD of Environmental Monitoring (DEM). July 31,1986. Memorandum from J. Mulligan to R.P. Wilms, Director,
NC-DEM, Re: Texasgulf Chemicals Co., Beaufort County.
58 Texasgulf. July 21,1988. Preliminary Contamination Assessment at Cooling Ponds No. 1 and 2, Texasgulf Inc. Phosphate
Operations, Aurora, North Carolina.
59 NC-DEM. February 25,1986. Memorandum from RJC. Thorpe to J. Mulligan, Washington Regional Office, NC-DEM, Re:
Texasgulf Chemicals Company, Beaufort County.
*° NC-DEM. February 10,1987. Memorandum from RJC. Thorpe to L.P.Benton, Jr., Deputy Director, NC-DEM, Re: Fish Kill,
Texasgulf Chemicals Co.
61 NC-Environmental Management Commission (EMC). April 2,1987. Findings and Decision and Civil Penalty Assessment.
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Chapter 12: Phosphoric Acid Production 12-27
Recent investigations have focused on leakage from cooling ponds Nos. 1 and 2, which have resulted
in ground-water contamination of the first two water-bearing zones at the site.62 In 1988, Texasgulf
commissioned a Preliminary Contaminant Assessment for Cooling Ponds 1 and 2 in fulfillment of requirements
for the renewal of a zero discharge permit. As part of this study, Texasgulf installed a total of 21 monitoring
wells at the site in March and April of 1988. These monitoring wells included 10 wells at Cooling Pond No. 1,
nine wells at Cooling Pond No. 2, and two background monitoring wells.63
Initial ground-water samples, obtained from monitoring wells at each of the cooling ponds during
April 1988, show the results for the surficial aquifer and the Croatan Aquifer, which underlies the surficial
aquifer at the site,64 These results are displayed in Exhibit 12-6.
The first zone appears to be discharging to the facility's main effluent canal, while the direction of
ground-water flow in the next zone is toward the northeast and Pamlico Sound.65'66 Texasgulf subsequent-
ly began additional investigations to delineate the extent of contamination.67 Initial results appear to
support the initial conclusion that contamination is confined to the upper two water-bearing zones and that
the Yorktown formation has prevented downward migration of contamination.68 Texasgulf s Remedial
Action Plan is currently under review by the NC-DEM.69
Louisiana
Agrico Chemical Co., Donaldsonville, Louisiana
AGRICO Chemical Company's Faustina Works phosphoric acid plant, which is located in
Donaldsonville, Louisiana, began operations in 1974. Approximately 68 residents inhabit land within one mile
of the facility. Receiving waters are the Mississippi River and the St. James Bayou.
Gypsum waste is slurried with process wastewater to a stacking area, where the solids settle out, and
the water drains into adjacent ponds or clearwells.
This facility has experienced problems with elevated concentrations of phosphorus, fluoride and acid
pH levels in surface and ground waters. Emergency discharges of untreated waters to surface water have
occurred periodically throughout much of the 1980s; contamination of the ground water was reported in 1986.
EPA Region VI has prohibited the discharge of gypsum into the Mississippi River. About 1983,
Agrico requested a modification of its NPDES Permit from EPA to allow Agrico to discharge gypsum to the
Mississippi River under certain conditions. Agrico argued that the 1973 impoundment design was based on
Florida facilities, and that the Louisiana climate and soils are different. Agrico stated that the height
62 Texasgulf. July 21, 1988. Preliminary Contamination Assessment at Cooling Ponds No. 1 and 2, Texasgulf Inc. Phosphate
Operations, Aurora, North Carolina.
63
Ibid.
64 Texasgulf. July 21,1988. Preliminary Contamination Assessment at Cooling Ponds No. 1 and 2, Texasgulf Inc. Phosphate
Operations, Aurora, North Carolina.
65 NC-DEM. December 13,1988. Memorandum from B. Reid to A. Moubeny, Re: Texasgulf, Inc. Renewal of Permit No.
2982, Cooling Ponds Not. 1 and 2.
66 NC-DEM. January 17,1989. Memorandum from R. Jones to C. McCasltill, Sup. State Engineering Review Unit, Permits and
Engineering Branch, Re: Permit Renewal No. 2982 Cooling Ponds #1 and #2 Texasgulf, Inc.
47 NC-DEM. December 13,1988. Memorandum from B. Reid to A. Moubeny, Re: Texasgulf, Inc. Renewal of Permit No.
2982, Cooling Ponds Nos. 1 and Z
68 NC-DEM. June 3,1989. Memorandum from B. Reid to R. Smithwick, Re: Texasgulf, Inc. Remedial Action Plan Cooling
Ponds No. 1 and No. 2.
69 Ardaman & Associates. February 6,1990. Letter from T.S. Ingra and J.E. Garlanger to W.A. Scrumming, Texasgulf, Re:
Response to Deficiencies Noted by DEM Concerning the Cooling Pond No. 1 and No. 2 Remedial Action Plan and Proposed Revised
Remedial Action Plan, Texasgulf Phosphate Operations.
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12-28 Chapter 12: Phosphoric Acid Production
Exhibit 12-6a
Ground-water Quality at Cooling Ponds 1 and 2 in the Surficial
Aquifer Confined Sand Layer
Parameter
Phosphorus (Total)
Fluoride
Chloride
SuKate
Total Dissolved Solids
State Drinking Water
Standard (mg/L)
-
1.5
250
-
500
Cooling Pond 1 (mg/L)
42.5 - 6,475
1 .5 - 2,790
151 - 189
3,648 - 4,337
5,685 - 27,783
Cooling Pond 2 (mg/L)
0.04-660
0.2 - 6.5
20-228
ND - 3,586
255 - 4,444
Exhibit 12-6b
Ground-water Quality at Cooling Ponds 1 and 2 in the Croatan
Aquifer Confined Shell Layer
Parameter
Phosphorus (Total)
Fluoride
Chloride
Sutfate
Total Dissolved Solids
State Drinking Water
Standard (mg/L)
-
1.5
250
-
500
Cooling Pond 1 (mg/L)
0.3 - 125
0.2-2.5
32-184
374 - 2,447
915-6,722
Cooling Pond 2 (mg/L)
0.05 - 32
0.1 - 0.5
11 -71
2.9-436
219-1,451
limitation meant that the original 240 hectares (600 acres), which would have lasted until about 1998 would
now last only until 1989.70
In addition, Agrico stated further that "[a]nother related consequence is that the amount of
contaminated run-off produced will increase geometrically as the impoundment acreage expands....Of the
alternatives considered, only the "River Disposal/Partial Impoundment* option represents a reasonable and
environmentally feasible alternative." Agrico concluded that "the water imbalance problem caused by
continued total impoundment would result in an increased potential for the release of contaminated water."71
On April IS, 1983, a portion of Agrico's 62-foot gypsum stack failed structurally and released 230,000
cubic meters (60 million gallons) of water from its 40 hectare (100-acre) pond onto plant property.72173'74 The
70 U.S. Environmental Protection Agency, Region 6. Undated. Report submitted by attorneys for Agrico Chemical Company,
Kean, Miller, Hawthorne, D'Annond, McCowan & Jarman, and Hall, Estill, Hardwick, Gable, Collingsworth & Nelson, Re: Agrico
Chemical Company, NPDES Permit LA0029769.
71 Ibid.
72 Agrico. 1983. Letter from R.A. Woolsey, Plant Manager to 1. Dale Givens, Administrator DNR, Re: WPCD Inspection of
the Faustina Facility on April 22,1983.
73 Louisiana DNR. May 11,1983. Installation Inspection Forms, completed by Susan Stewart, Installation Representative.
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Chapter 12: Phosphoric Acid Production 12-29
spilled water was pumped to another gypsum holding stack; concern over the potential failure of this stack,
however, led Agrico to discharge the untreated water to the Mississippi River over a period of several weeks.
These discharges exceeded permit limits.75'76 After the pond failure, water of pH 2 was found flowing in
an on-site drainage ditch at approximately 20 gpm into the St. James Bayou. The large volume of released
water had destroyed a dam that controlled flow from the drainage ditch into the St. James Canal. Agrico
reinstalled the dam on April 22, 1983, and transferred the low pH water still in the dammed section of the
ditch back to the gypsum pond system. Agrico checked the water in St. James Canal, concluding that it did
not seem affected by the low pH water discharged to it as a consequence of the April 15, 1983 gypsum pond
failure.77'78
Due to heavy rainfall, Agrico has continued to periodically perform emergency discharges of untreated
stormwater from the clearwell, as occurred in March and again in June 1987. In its letter of notification,
Agrico stated that "additional rain could result in catastrophic levee failure leading to loss of life, personal
injury, or severe property damage."79
In March 1986, Agrico reported to LA DEQ that the water along the length of the north and east
phosphogypsum perimeter ditches might be "slightly impacted" by phosphate, sulfate, and fluoride.80
In August 1986, Agrico submitted to LA DEQ a Hydrologic Assessment report for the Donaldsonville
facility. LA DEQ regarded the reported situation as requiring corrective action: "Contamination of the
shallow ground water, although by constituents which are not of great concern, poses a threat to drinking
water. The Department's position is that the same physical characteristics that allow the contaminants to
travel through the shallow silt faster than your theoretical model are present in the underlying clays."81
Even under non-emergency circumstances, Agrico has had difficulty keeping in compliance with
NPDES permit limitations. In April 1987, an investigator reported that discharges from Agrico's inactive
gypsum impoundment (Outfall 002) were in exceedance (up to 35 times) of permitted levels. However, the
investigator determined that no action would be taken "until reissuance of new permit."82
In August 1987, LA DEQ determined that Agrico could not comply with the Louisiana Water
Discharge Permit System that had been effective since March 1987.83 LA DEQ issued an Administrative
Order to Agrico to allow the facility to temporarily discharge water from gypsum stacks until standards were
met.84'85-86'87
7\...continued)
74 U.S. Environmental Protection Agency, Region 6. Undated. Report submitted by attorneys for Agrico Chemical Company,
Kean, Miller, Hawthorne, D'Armond, McCowan & Jarman, and Hall, Estill, Hardwick, Gable, Collingsworth & Nelson, Re: Agrico
Chemical Company, NPDES Permit LA0029769.
75 Ibid.
76 Louisiana DEQ. October 25,1984. Memorandum from Patricia L. Norton, Secretary, to J. Dale Givens, Assistant Secretary,
Re: Agrico Chemical Co.
77 Agrico. April 29,1983. Letter from RA. Woolsey, Plant Manager to J. Dale Givens, Administrator DNR, Re: WPCD
Inspection of the Faustina Facility on April 22, 1983.
78 Louisiana DNR. May 11,1983. Installation Inspection Forms, completed by Susan Stewart, Installation Representative.
79 Agrico. June 17,1987. Letter from R.A. Woolsey, Plant Manager to Myron O. Knudson, U.S. EPA Region 6 Director Water
Management, Re: NPDES Permit Number. LA0029769. With attachment.
80 Agrico. March 12,1986. Letter from Susan P. Stewart, Manager, Energy and Environmental Control to Gerald Healy,
Administrator, LA DEQ Solid Waste Division, Re: Agrico Phosphogypsum Site (P-0063) GD-093-0791.
81 Louisiana DEQ. August 22,1986. Letter from George H. Cramer, II, Administrator to Susan Stewart, Agrico Manager
Energy and Environmental Control, Re: Hydrogeologic Assessment, Final Report GD-093-0791.
82 U.S. Environmental Protection Agency, Region 6. 1986-88. NPDES Violation Summaries, from 10A8/86 - 4/12/88.
83 Louisiana DEQ. August 17,1987. Inter-office Letter, from G.S. Chambers to DJ. Miller, Re Faustina Plant - Administrative
Order.
84
Ibid.
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12-30 Chapter 1.2: Phosphoric Acid Production
According to the LA DEQ, this facility has not experienced non-compliance or emergency release
problems since those outlined in this section.
Arcadian, Ge/smar, Louisiana
This facility, formerly owned by Allied Chemical, has been operational since 1967. The plant is
situated along the Mississippi River, in Geismar, Louisiana, northeast of the intersection of LA Highways 75
and 3115. Approximately 150 residents live within 1.6 km (1 mile) of the facility.88 There are private
drinking water wells within a 1.6 km radius of the facility.89'90 The water table occurs at 24 meters (80
feet) below the land surface in the wet season, and 30 meters in the dry season.91 The Mississippi River
receives the discharges from this facility.
The phosphogypsum waste is slurried to the stack with process wastewater, which drains into a
retention pond referred to as "the clearwell." There are four clearwells of differing sizes at the site, one of
which is described as active. Six phosphogypsum stacks occupy the site as well, one or two of which appear
to be active.
The effluent guidelines prohibiting discharge of process pollutants from a wet phosphoric acid facility
were rescinded for the plants on the lower Mississippi due to poor soil stability and excess precipitation. EPA
Region 6 described the condition as follows: The withdrawal of the guidelines allowed the creation of the
concept of active and inactive impoundments. The inactive impoundment drainage may be discharged directly
to the receiving stream without limits provided no further wastes are sent to the inactive system and the
discharge meets water quality standards."92
Two major categories of contaminant release to the environment have occurred at this facility:
radioactivity releases to the ground water and clearwell discharges causing excessive phosphorus and fluoride
loadings, as well as elevated pH, to surface waters. A third area of concern is fluoride fugitive emissions from
the clearwell.
Arcadian has installed numerous monitoring wells throughout the gypsum stack and clearwell areas.
Arcadian's ground-water monitoring report for the second half of 1988 showed gross alpha radiation in well
P4 at 95 ± 31 pCi/L and 60 ±14 pCi/L in well P10.93 The MCL for gross alpha radiation is 15 pCi/L.
These releases are not extensively documented in the files reviewed; the documents reviewed did not discuss
actions taken in response to the results presented.
The net surplus of precipitation in this region has prompted Arcadian to perform emergency
discharges of excess water from its clearwell. Arcadian has justified this action by stating that until the
NPDES permit effluent limitations are modified, there are no other environmentally acceptable alternatives
"(...continued)
85 Louisiana DEQ Water Pollution Control Division. 1987-88. Administrative Order issued by DEQ.
86 U.S. Environmental Protection Agency. September 8,1967. NPDES Compliance Inspection Report.
87 U.S. Environmental Protection Agency, Region 6. 1988. Administrative Order, Re: Agrico Chemical Company, Docket No.
VI-87-1411.
88 Arcadian. April 21,1989. "National Survey on Solid Wastes from Mineral Processing Facilities."
89 Ibid.
90 Gentry, J. January 20,1989. Handwritten letter to LADEQ, Re: Questions and Comments on Permit Application.
91 Arcadian. April 21,1989. "National Survey on Solid Wastes from Mineral Processing Facilities."
92 U.S. Environmental Protection Agency, Region 6. May 11,1989. Letter from K.G. Huffman to M. Harboun, of Kean et al,
Attorneys at Law, Re: Arcadian Corporation, NPDES Permit No. LA0066257.
93 Arcadian. January 15, 1989. Letter from JJ. Baker to T. Hardy, OSHW LADEQ, Re: ID #GD-005-1822 Ground Water
Monitoring Report.
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Chapter 12: Phosphoric Acid Production 12-31
to the emergency bypass of the clearwell water.94 The accumulation of facts throughout the documents
suggests that excess water can cause failure of the gypsum stack or of the clearwell walls. During a discharge
on February 27, 1987, Arcadian stated that the action was necessary "to prevent possible injury and severe
property damage."95 Such a discharge occurred again beginning on March 10 of the same year.96 During
these discharges, pH values ranged from 1.3 to 2.5; phosphorus concentrations from 3,688 mg/L to 7,960 mg/L;
and fluorine concentrations from 6,188 to 14,649 mg/L.
An EPA NPDES Violation Summary, based on discharge monitoring reports from March 1986 to
December 1987, showed that Outfall 003 violated effluent limits each month from at least December 1985 until
August 1987. No enforcement action was taken for any of these violations. Since February of 1987, the EPA
inspector has noted: "No action taken - waiting for an enforceable permit." Contaminant concentrations were
similar to those listed above.
On December 8,1988, EPA Region VI issued an Administrative Order to Arcadian regarding several
violations, including the discharge on October 28 of that year of calcium sulfate run-off (Outfall 003)
containing total phosphorus of 8,176 Ibs/day, exceeding the permitted limit of 7,685 Ibs/day.97
According to the LA DEQ, this facility has not experienced non-compliance or emergency bypass
problems since those outlined in this section.
Louisiana - Other
The management histories described for the above Louisiana facilities are also typical of the other
Agrico facilities (Hahnville and Uncle Sam).
12.3.3 Findings Concerning the Hazards of
Phosphogypsum and Process Wastewater
Based upon the detailed examination of the inherent characteristics of phosphogypsum and process
wastewater arising from the production of wet process phosphoric acid, the management practices that are
applied to these wastes, the environmental settings in which the generators of the materials are situated, and
the numerous instances of documented environmental damage that have been described above, EPA concludes
that current practices are inadequate to protect human health and the environment from the potential danger
posed by these wastes.
Intrinsic Hazard of the Wastes
Review of the available data on phosphogypsum and its leachate constituent concentrations indicates
that concentrations of 12 constituents exceed one or more of the screening criteria by more than a factor of 10,
and that maximum chromium and phosphorus concentrations exceed the screening criteria by factors of greater
than 1,000. In addition, two samples of phosphogypsum (out of 28) contained chromium concentrations in
excess of the EP toxicity regulatory level, and phosphogypsum frequently contains uranium-238 and its decay
products at levels that could present a high radiation hazard if the waste is allowed to be used in an
94 Kcan, et al, Attorneys at Law. November 6, 1984. Letter from M.N. Harbourt to J.V. Ferguson, EPA Region 6, Re: Notice
of Anticipated Bypass, NPDES Permit No. LA00662S7, Arcadian Corp., EPA File No. 7945-1.
95 Arcadian. February 27,1987. Letter from M.N. Harbourt to J. Van Buskirk, EPA Region 6 and J.D. Givens, LADEQ, Re:
Notice of Anticipated Bypass and Request for Order Authorizing Bypass.
96 Kean, et al, Attorneys at Law. March 19,1987. Letter from M.N. Harbourt to J. Von Buskirk, EPA Region 6, Re: Arcadian
Corporation - NPDES Permit Number LA-0066257, EPA File Number 7945-1.
97 U.S. Environmental Protection Agency, Region 6. December 8,1988. Cover letter from M.O. Knudson to HJ. Baker,
Arcadian, Re: Administrative Order Docket No. VI-89-043, NPDES Permit No. LA0066257. 1Z8/8&. (Administrative Order
attached).
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12-32 Chapter 12: Phosphoric Acid Production
unrestricted manner. This finding leads EPA to conclude that the intrinsic hazard of this waste is moderate
to high.
Review of the available data on phosphoric acid process wastewater constituent concentrations
indicates that phosphorus and phosphate are present at concentrations that sometimes are more than 100,000
times the screening criteria, arsenic and phenol are present at concentrations more than l.OOQ times the
screening criteria, and 15 additional constituents exceed a screening criteria by a factor of at least 10. In
addition, process wastewater exhibits the RCRA hazardous waste characteristics of corrosivity (i.e., pH < 2)
and exhibits the characteristic of EP toxicity (based on cadmium, chromium, and selenium concentrations).
The wastewater also contains radium-226, gross alpha radiation, and gross beta radiation levels that could pose
an unacceptably high radiation hazard if the wastewater is mismanaged. Based on these findings, EPA
concludes that the intrinsic hazard of phosphoric acid process wastewater is high.
Potential and Documented Danger
The documented cases of dangers to human health and the environment indicate that phosphogypsum
and process wastewater constituents have been released to ground water at a number of facilities and, at some
sites, have migrated off-site to potable drinking water wells in concentrations that are well above hazard
criteria. Based on the analysis of the damage case evidence, EPA concludes that management of
phosphogypsum and process wastewater in stacks and ponds can release contaminants to the subsurface.
Given the hydrogeologic setting and ground-water use patterns in the vicinity of most phosphoric acid plants,
released contaminants threaten human health via potential drinking water exposures and render ground-water
resources unsuitable for potential use.
Based on the analysis of the damage case evidence, it is clear that management of phosphogypsum
and process wastewater in stacks and ponds can and does release contaminants to nearby surface waters.
Given this evidence of releases, the proximity of most phosphoric acid plants to surface water bodies, and
surface water use patterns, EPA concludes that at many phosphoric acid plants these released contaminants
migrate to rivers and bays and threaten human health via drinking water exposures, threaten aquatic life, or
render surface water resources unsuitable for potential consumptive uses.
EPA risk estimates demonstrate that phosphogypsum stacks pose a considerable air pathway cancer
risk as a result of radon emissions from the stacks, with minor contributions from radioactive and
nonradioactive constituents in windblown phosphogypsum. EPA estimates a maximum total air pathway
lifetime cancer risk for a maximally exposed individual of approximately 9xlO"5. This risk is primarily from
inhalation of radon emitted from stacks (9xlO~5), with minor contributions from the inhalation of windblown
phosphogypsum panicles containing radionuclides (2X10"6) and arsenic and chromium (7xlO~7).
12.4 Existing Federal and State Waste Management Controls
12.4.1 Federal Regulation
Section 3001(b)(3)(B)(iii) of RCRA provides the EPA Administrator with explicit authority to
regulate the use of the use of solid wastes from phosphate rock processing for construction or land reclamation
so as to prevent radiation exposure which presents an unreasonable risk to human health. EPA has not
availed itself of this authority to date, but plans to consider regulatory options under this provision of RCRA
to limit the off-site use in construction of elemental phosphorus slag, another special waste from mineral
processing (see Chapter 7).
Off-site use of phosphogypsum has already been prohibited by the final National Emission Standards
for Hazardous Air Pollutants (NESHAP) for radionuclides that was promulgated on December 15,1989 (54
FR 51654). This rule requires that as of the effective date of the rule (March 15, 1990), phosphogypsum be
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Chapter 12: Phosphoric Acid Production 12-33
disposed in stacks or in mined-out areas, effectively prohibiting use as a construction material or agricultural
soil supplement.98
Under the Clean Water Act, EPA has the responsibility for setting "effluent limitations," based on
the performance capability of treatment technologies. These "technology based limitations," which provide the
basis for the minimum requirements of NPDES permits, must be established for various classes of industrial
discharges, including a number of mineral processing categories.
Permits for mineral processing facilities may require compliance with effluent guidelines based on best
practicable control technology currently available (BPT) or best available technology economically achievable
(BAT). BPT effluent limitations of process wastewater from wet-process phosphoric acid, normal
superphosphoric acid, and triple superphosphoric acid include (40 CFR 418.12(c)):
Pollutant
Total Phosphorus
Fluoride
Total Suspended Solids
Dally Maximum
105 mg/L
75 mg/L
150mg/L
Monthly Average
35 mg/L
25 mg/L
50 mg/L
Effluent limitations concerning the concentrations of pollutants contained in (1) the discharge of
contaminated non-process wastewater after application of BPT and BAT (40 CFR 418.12(d) and 418.13(d)),
(2) discharges of process wastewater related to phosphoric acid production from existing sources after
application of BAT (40 CFR 418.13(c)), and (3) process wastewater from defluorination of phosphoric acid
after application of BPT and BAT are identical and as follows (40 CFR 422.52(c) and 42153(c):'9
Pollutant
Total Phosphorus
Fluoride
Dally Maximum
105 mg/L
75 mg/L
Monthly Average
35 mg/L
25 mg/L
No discharges of process wastewaters from the production of phosphoric acid or from the
defluorination of phosphoric acid are allowed from new sources.
In cases where the State does not have an approved NPDES program, such as Texas, Louisiana, and
Florida, EPA Regional personnel have stated that EPA applies the above guidelines. However, EPA may also
adopt State water quality standards for the management of these discharges, if applicable. In Idaho, which also
does not have an approved NPDES program, the Federal guidelines listed above would apply. EPA Regional
staff have not been available to confirm current policy regarding discharges from phosphoric acid facilities.
The State of Florida does not currently have an EPA-approved NPDES program. Therefore, existing Federal
regulations concerning the management of wastes from the production of phosphoric acid, would apply for
facilities in this State. Wastes from phosphoric acid production are subject to the effluent limitation guidelines
set forth in 40 CFR Part 418 Subpart A.
The Chevron Chemical Company phosphoric acid facility located in Rock Springs, Wyoming is
situated on federal lands managed by the Bureau of Land Management (BLM). The Federal Land Policy and
Management Act of 1976 (FLPMA, 43 USC 1732, 1733, and 1782) authorizes BLM to regulate mining
*On April 10,1990 EPA published a Notice of Limited Reconsideration that provided a limited class waiver that allows continued
use of phosphogypsum for agricultural uses for the duration of the current growing season, but not to extend beyond October 1,1990.
This notice also solicited comment on alternative uses of pnosphogypsuin, i.e., management practices other than disposal.
99 The limitations for defluorination process wastewater also include daily maximum limits of 150 mg/L and 6-9 and monthly
average limits of 50 mg/L and 6-9 for TSS and pH respectively.
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12-34 Chapter 12: Phosphoric Acid Production
activities on its lands with respect to the environmental effects of such activities. BLM regulations
implementing this law (43 CFR 3809) are intended to prevent unnecessary or undue degradation of its lands,
or lands that are under consideration for inclusion in the national wilderness system. These regulations
provide for reclamation of lands disturbed by mining, hence, are not directly applicable to mineral processing
activities.
12.4.2 State Regulation
The 21 facilities in the phosphoric acid sector are located in seven states, including Florida, Louisiana,
Idaho, Mississippi, North Carolina, Texas, and Wyoming. All of these states except Wyoming were selected
for regulatory review (see Chapter 2 for a discussion of the methodology used to select states for regulatory
study). The majority of the 21 phosphoric acid facilities are located in Florida, Louisiana, and Idaho, which
have twelve, three, and two facilities, respectively. Based on the distribution of facilities, therefore, state-level
regulation of phosphoric acid processing wastes is of particular interest in the States of Florida, Louisiana,
and Idaho.
As a general overview, six of the seven states with phosphoric acid processing facilities (all but
Wyoming), adopt the federal exclusion from hazardous waste regulation for special wastes from mineral
processing. Florida regulates wastes from the production of phosphoric acid under its solid waste rules, while
Louisiana and Texas classify and manage such wastes as industrial solid waste. Mississippi and North Carolina
exempt wastes generated in all types of mineral processing facilities from regulation as solid wastes. No
requirements in Idaho's solid waste regulations apply to these wastes. Finally, three of seven states (North
Carolina, Mississippi, and Wyoming) have EPA-approved NPDES programs while all seven states have air
quality control regulations or standards that may be applicable to wastes from mineral processing facilities.
As noted above, most of the phosphoric acid processing facilities under study are located in Florida.
Also as noted, Florida adopts the federal exclusion from hazardous waste regulation for mineral processing
wastes. The state addresses phosphoric acid processing wastes under its solid waste regulations, though these
regulations do not contain requirements pertaining specifically to phosphogypsum stacks or process wastewater
cooling ponds. The state issues two types of permits for solid waste disposal activities at phosphoric acid
facilities, including an industrial wastewater discharge permit (required for cooling ponds and maintained for
some old stacks), and a solid waste disposal permit required of new stacks. Recent monitoring efforts have
prompted the state to establish additional controls over stacks. Florida now requires that all discharges to
ground water, in addition to established zones of discharge, be addressed by an appropriate permit. The state
also applies modified landfill requirements, interim requirements, and limited wastewater facilities regulations,
and is in the process of modifying the solid waste regulations with regard to design and operating standards,
closure requirements, and financial responsibility requirements applicable to phosphogypsum stacks and
cooling ponds.
Current regulation of phosphoric acid processing wastes in Florida, therefore, consists primarily of
the requirement to obtain a permit for discharges to ground water and the requirement that new stacks and
expansions of existing stacks be clay-lined and undergo formal closure. Under this policy, closure requirements
include cover adequate to prevent infiltration and run-off controls. Further, all cooling ponds in the state
must have run-on/run-off controls. The state also may place waste disposal location restrictions, performance
standards, and operating requirements on a facility's solid waste disposal permit. The Florida Department of
Environmental Regulation has the authority to conduct on-site inspections, issue administrative and consent
orders, and require remedial action, though it does not have the authority to fine facilities for non-compliance.
Finally, although air emissions from the phosphate industry are regulated under the state's air pollution rules,
state officials indicated that phosphogypsum stacks typically crust over or are managed as pan of a wet system
so that fugitive dust emissions traditionally have not been considered a problem.
Louisiana, with three phosphoric acid processing facilities, also excludes mineral processing wastes
from regulation as hazardous waste. Louisiana classifies and regulates mineral processing wastes as industrial
solid wastes. Although no requirements have been drafted specifically for phosphogypsum stacks, facility
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Chapter 12: Phosphoric Acid Production 12-35
owners/operators must comply with provisions for soils (e.g., stability, permeability), hydrologic characteristics,
precipitation run-on and run-off, location standards, security, safety, and waste characterization. New stacks
must have liners as well. During closure, the owner/operator must emplace a final cover or some alternate
erosion control measure. Similarly, process wastewater cooling ponds must meet industrial waste surface
impoundment requirements such as run-on controls, liner requirements, design standards (e.g., to prevent
overtopping and minimize erosion), and waste characterization and ground-water monitoring requirements.
Surface impoundments must be dewatered and clean-closed (i.e., all residuals removed) or closed according
to solid waste landfill closure provisions. Owners/operators of both phosphogypsum stacks and process
wastewater ponds must maintain financial responsibility for the closure and post-closure care of those units.
In addition to these solid waste regulations, the three facilities in Louisiana must comply with federal NPDES
permits and Louisiana Air Emissions Permits. Under the air permits, the facilities must be operated in a
manner to minimize fugitive dust and could be required to undertake fugitive dust controls, such as the
application of chemicals, asphalt, or water, if deemed necessary by the state. Finally, the state requires that
owners/operators obtain a permit in order to construct a new facility or make a major modification to an
existing facility.
Like Florida and Louisiana, Idaho, with two phosphoric acid processing facilities, excludes mineral
processing wastes from its hazardous waste regulations. Unlike all of the other states with phosphoric acid
processing facilities, however, Idaho does not apply any solid waste regulatory requirements to either
phosphogypsum stacks or process wastewater cooling ponds. Moreover, the state does not have an approved
NPDES program and, although the two facilities located in Idaho are broadly responsible for reasonable
control of fugitive dust emissions, the state does not specifically address stacks or ponds in the facilities' air
permits.
As noted, Mississippi, North Carolina, and lexas each have a single phosphoric acid facility and
exclude those facilities from hazardous waste regulations. The facility located in Mississippi, which is not
currently in operation, does have a current Mississippi NPDES permit. Because this facility disposes of its
waste on site, however, the state does not require that the owner/operator obtain a solid waste management
permit and does not plan to address the phosphoric acid wastes unless a threat to public health and the
environment is demonstrated. The facility in North Carolina has a current North Carolina NPDES permit
for its wastewaters. In accordance with a state-issued mining permit, the facility currently uses its
phosphogypsum as fill for mined-out areas. The state does not regulate the stacks as solid wastes, but rather
addresses them with non-discharge permits issued by the Water Quality Section of the Division of
Environmental Management. North Carolina has initiated several consent agreements with the facility to
address releases to surface and ground waters. .The state also recently promulgated new air regulations that
address radionuclide contaminants and may result in increased fugitive dust emission controls for
phosphogypsum stacks. As with Mississippi, the facility in Texas has not been required to obtain a solid waste
permit because it disposes of its wastes on property owned by the facility owner/operator. The facility has
notified the state of its waste management activities, however, and has obtained federal NPDES and lexas
wastewater discharge permits. Both North Carolina and lexas have addressed air emissions from
phosphogypsum stacks only under general emission requirements. The final state with a phosphoric acid
processing facility, Wyoming, was not studied in detail for this report Wyoming appears to regulate its single
facility under solid waste regulations and the state's approved NPDES program.
In summary, the two states with the most phosphoric acid processing facilities, Florida and Louisiana,
appear to regulate those facilities most comprehensively. Of the remaining states, Mississippi, lexas, and
Wyoming have placed fewer regulatory requirements on the phosphoric acid processing wastes managed within
their borders, while Idaho has imposed essentially no requirements on the two facilities located within the
state. In all cases, the wastes are addressed in general by NPDES, air, and solid waste landfill and surface
impoundment requirements only, and not by regulations tailored specifically to phosphogypsum stacks or
process wastewater cooling ponds.
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12-36 Chapter 12: Phosphoric Acid Production
12.5 Waste Management Alternatives and Potential Utilization
12.5.1 Waste Management Alternatives
\Vaste management alternatives, as discussed below, include alternative processes for manufacturing
phosphoric acid and methods of purifying (i.e., reducing concentrations of radionuclides and/or other
contaminants) the phosphogypsum so that it can be safely used in agriculture or construction. Direct recycling
of phosphogypsum is not a viable alternative, because the phosphogypsum itself cannot be used in the
production of phosphoric acid, although it is already common practice to recycle the process water used to
slurry the phosphogypsum. One exception to this, as is discussed briefly in the section on utilization, is the
production of sulfur dioxide (SOj) by the thermal decomposition of phosphogypsum, which can be recycled
to the manufacturing process as sulfuric acid.
Process Alternatives for Manufacturing Phosphoric Acid
There are a number of variations of the basic wet-acid process used to manufacture phosphoric acid.
These alternative processes are considered in this section because the phosphogypsum that they generate may
differ in its degree of hydration (hemihydrate vs. dihydrate) at the time of generation, which can determine
which purification methods can be applied to the phosphogypsum, and how efficiently they can remove the
impurities. In addition, the amount of preprocessing required before some types of utilization (e.g., as wall
board or plaster) can also vary with the production process used. Unfortunately, there is insufficient data
available to attempt an evaluation the volume, composition, or potential hazard(s) of the phosphogypsum
generated by the different processes. Consequently, this discussion focuses on the differences that could be
relevant to the subsequent treatment, utilization, or disposal of phosphogypsum generated by the different
production processes.
Description
The processes to be discussed are the classic Prayon and Nissan-H processes which generate the
dihydrate form of phosphogypsum (CaSO4 • 2H2O); and the Central-Prayon and Nissan-C processes, which
generate the hemihydrate form of phosphogypsum (CaSO4 • ViH2O).
In the classic Prayon process, the dihydrate phosphogypsum is filtered out of the solution produced
by the digestion of phosphate rock by sulfuric acid. The phosphogypsum is then pumped as a slurry to gypsum
stacks for disposal.100-101
In the Central-Prayon process, the dihydrate phosphogypsum is filtered out of the solution produced
by the digestion of phosphate rock by sulfuric acid. The phosphogypsum is convened to the hemihydrate form
by heating it and adding sulfuric acid, whereupon the hemihydrate/phosphogypsum is extracted from the acid
slurry by counter-current washing, and the liquid is recycled to the phosphate rock digestion process, and the
hemihydrate slurry being sent to the stacks for disposal.102
In the Nissan-H process, the phosphate rock is digested by sulfuric acid at a high temperature which
causes most of the phosphate rock to decompose and the hemihydrate form of phosphogypsum to be generat-
100 Pcna, N., Utilization of the Phosphogvpgum Produced in the Fertilizer Industry. UNDDO/IS.533, United Nations Industrial
Development Organization (UNIDO), May 1985, p. 30.
101 Muehlberg, P.E, 3.T. Reding, 8.P. Shepherd, Terry Parsons and Ghynda E. Wiltons, Industrial Process Profiles for
Environmental Use: Chapter 22. The Phosphate Rock and Basic Fertilizer Materials Industry. EPA-600/2-77-023v, Environmental
Protection Technology Series, prepared for Industrial Environmental Research Laboratory, ORD, U.S. Environmental Protection
Agency, February 1977, p. 21.
102 Ibid., p. 31.
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Chapter 12: Phosphoric Acid Production 12-37
ed.103 The hemihydrate slurry is cooled and recrystallized to dihydrate by using seed crystals of dihydrate
phosphogypsum. This recrystallization step results in the formation of phosphogypsum crystals which can be
easily filtered, and are believed to be of sufficient quality to be utilized in building materials without additional
treatment.104-105
The Nissan-C process is very similar to the Nissan-H process, the main difference being that the
hemihydrate slurry is recrystallized by both cooling it and changing its acid concentration, which results in
phosphoric acid concentrations of 45-50 percent without evaporation (as opposed to the 30-35 percent
normally produced by the dihydrate processes) and in a higher quality phosphogypsum.106
Current and Potential Use
It is uncertain which of the above processes are used by each of the phosphoric acid facilities,
although EPA believes that at least two or three of the facilities use one of the processes (Central-Prayon or
Nissan-C) which generate hemihydrate phosphogypsum, and that the rest of the facilities use one of the
processes (classic Prayon or Nissan-H) which generate dihydrate phosphogypsum.
There do not appear to be any insurmountable obstacles preventing any of the facilities from using
any of the available production processes. Some of the reasons why particular facilities use, or have converted
to, a particular process have been that the hemihydrate processes are more energy efficient because the
phosphoric acid that they produce is more concentrated (hence, requires less evaporative concentration, which
is energy-intensive), and that the dihydrate processes are easier to control and maintain. If it becomes
necessary to reduce the radionuclide content in the phosphogypsum (see the discussion of phosphogypsum
purification below) so that it could be utilized rather than disposed (see section 12.5.2), facilities might have
more incentive to begin using one of the processes which generate hemihydrate phosphogypsum, since the two
purification methods which employ acid digestion require anhydrite or hemihydrate phosphogypsum.
Purification of Phosphogypsum
Utilization of phosphogypsum in construction and agriculture is constrained by the presence of
impurities and hazardous constituents in the waste. Constituents such as radium-226 and arsenic may need
to be removed because of the hazards they may present to human health and the environment, while
phosphates and fluorides need to be removed for technical reasons related to the methods of utilization. The
impurities include insolubles such as silica sand and unreacted phosphate ore; occluded water soluble
phosphoric acid and complex fluoride salts; and interstitially trapped ions within the phosphogypsum crystal
lattice, such as HPO42~, A1F52", and radioactive radium-226.107
Description
Several processes for removing radium-226, as well as the other impurities, have recently been
developed.108'109 These processes involve either acid digestion of the phosphogypsum or simple physical
removal of the more radioactive portions of the phosphogypsum.
103 Ibid., p. 14.
104 Ibid-. P- 16-
105 The absence of supporting data has prevented EPA from evaluating the validity of this statement.
106 Muehlberg, op., til., p. 18.
107 Palmer, J.W, and J.C. Gaynor, Phosphogypsum Purification. USG Corporation, Liberryville, Illinois, May 30,1985, p. 1.
108 Ibid.
109 Palmer, J.W., Process for Reducing Radioactive Contamination in Phosphogvpgum. U.S. Patent 4338,292 to USG
Corporation, June 14, 1983, p. 2.
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12-38 Chapter 12: Phosphoric Acid Production
The method of physical separation can reduce the radionuclide concentration of the phosphogypsum
by approximately 30 percent. The method involves the use of a hydrocyclone to remove the phosphogypsum
crystals smaller than 30 microns (which contain the greatest proportion of radionuclides) from the bulk of the
phosphogypsum.110
While the two acid digestion processes are more complicated and costly, they can remove nearly all
of the radioactive constituents. The acid digestion processes are similar to one another; the primary difference
between the processes is whether anhydrite (CaSO4) or hemihydrate (CaSO4 • ViH2O) is used as a reaction
intermediate in the purification sequence. Both processes can be applied to dihydrate phosphogypsum,
although it must first be dehydrated with sulfuric acid.
During the anhydrite purification method, phosphogypsum is placed in concentrated sulfuric acid
where it is dehydrated and reprecipitated as small anhydrite crystals. Most of the soluble ions are removed
from the phosphogypsum, while the radium-226 is precipitated with the anhydrite. (Silica sand also remains
with the solid anhydrite.) The anhydrite is rehydrated with a dilute solution of sulfuric acid at a temperature
less than 43°C, and gypsum seed crystals are used to speed up the rate of hydration. The remaining anhydrite
crystals, along with the radium-226, can be readily separated from the larger gypsum crystals, although some
of the very small anhydrite crystals adhere to the surface of the gypsum crystals, which increases the
radionuclide content of the purified phosphogypsum.
During the hemihydrate purification method, the hemihydrate slurry is cooled, purified gypsum seed
crystals are added, and large crystals of purified phosphogypsum are produced. Most of the radionuclides
remain in the hemihydrate crystals, and the large dihydrate phosphogypsum crystals are easily separated from
the smaller hemihydrate crystals.
The dilute sulfuric acid, used to rehydrate the anhydrite or hemihydrate, contains phosphate value
from the phosphogypsum that can be recovered at the phosphoric acid plant. Silica sand is removed from the
slurry by hydraulic classification.
An approximately 99.5 percent pure phosphogypsum can be obtained using either of these two
processes. The hemihydrate route gives a 1 pCi/g radiation level, while the anhydrite route gives a 3 pCi/g
level. Natural gypsum typically contains 1 to 3 pCi/g radiation.
Current and Potential Ute
In the literature reviewed by EPA, no evidence was found to indicate that any of the phosphoric acid
facilities are currently purifying their phosphogypsum. Future use of the purification methods will primarily
depend on how the regulations constrain the disposal and utilization of phosphogypsum (see section 12.S.2).
Of the three purification methods described above, the physical separation process has only limited
potential use. Since the physical separation process will only remove 30 percent of the radium-226, the use
of this process is limited to phosphogypsum containing 14 pCi/g or less of radium-226 (i.e., a 30 percent
reduction from 14 pCi/g will yield 9.8 pCi/g). This is assuming that phosphogypsum with a radium-226 content
of greater than 10 pCi/g could not be utilized (see 54 FR 13482, April 10,1990).
Exhibits 12-7 and 12-8 summarize phosphogypsum radium-226 content on a regional and facility-
specific basis. Facility-specific information was available for only 7 of the 21 phosphoric acid production
facilities. It should be noted that phosphate ores processed in Louisiana, Mississippi, and Texas originate from
Florida. The radium-226 content of the North Carolina phosphogypsum falls below the tentative threshold
level of 10 pCi/g radium-226 and, therefore, would not require purification. Phosphogypsum generated in
Florida, Idaho, Louisiana, and Mississippi have radium-226 concentration ranges too high for the physical
separation process to purify more than a fraction of the phosphogypsum to a level below the threshold level.
However, the phosphogypsum generated in Texas has a low enough radium-226 concentration that the method
110 Pena, N., Utilization of the Phosphogywum Produced in the Fertilizer Industry. UNIDO/IS.533, United Nations Industrial
Development Organization (UNIDO), May 1985, p. 32
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Chapter 12: Phosphoric Acid Production 12-39
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Chapter 12: Phosphoric Acid Production 12-41
of physical separation should be able to reduce the radium-226 concentration below the 10 pCi/g threshold
in most of the phosphogypsum generated.
Therefore, it appears that only a small portion of phosphogypsum produced annually could be
sufficiently purified by the physical separation technique. In order to reduce all the phosphogypsum to a level
at or below the 10 pCi/g threshold, the purification methods using acid digestion would be required.
Factors Affecting Regulatory Status
The residuals generated by the acid digestion purification of phosphogypsum have a specific activity
of up to 600 pCi/g111, and while the purification process generates a relatively low volume of waste, it is
very concentrated and may pose disposal problems that equal or outweigh those associated with the original
phosphogypsum. At this time, however, EPA does not have sufficient information to articulate a position on
the regulatory status of this residue. One waste management strategy which has been suggested for
immobilizing the radionuclides is to blend it with waste phosphatic clay suspensions (slimes) and allow the
mixture to solidify.112 The discussion in Section 12.5.2 on utilization of phosphogypsum in mine
reclamation provides an explanation of this approach.
While no information was found on the volume or radium-226 concentration of the waste resulting
from the physical separation method, it too would produce residuals with relatively high concentrations of
radium-226.
12.5.2 Utilization
Described below are a number of alternatives for utilizing phosphogypsum. Some of these uses, such
as agriculture and mine reclamation, already utilize significant amounts of phosphogypsum. Other alternatives
(e.g., use as a construction material) have been shown to be technically feasible, but for a variety of reasons
have not moved beyond the developmental stage of field testing in the U.S.
At the time of this assessment, it is uncertain which, if any, of the uses discussed below will be
allowed. EPA currently requires that phosphogypsum be disposed in stacks or mines, which precludes
alternative uses of the material,113 except for a limited class waiver for the agricultural use of
phosphogypsum, which will be in effect until October 1, 1990. EPA has, however, announced a limited
reconsideration of the rule requiring the disposal of phosphogypsum in stacks or mines, and has also given
notice of a "proposed rulemaking by which EPA is proposing to maintain or modify the rule to, alternatively
or in combination, (1) make no change to 40 CFR Pan 61, subpart R, as promulgated on October 31,1989,
(2) establish a threshold level of radium-226 which would further define the term "phosphogypsum", (3) allow,
with prior EPA approval, the use of discrete quantities of phosphogypsum for researching and developing
processes to remove radium-226 from phosphogypsum to the extent such use is at least as protective of public
health as is disposal of phosphogypsum in mines or stacks, or (4) allow, with prior EPA approval, other
alternative use of phosphogypsum to the extent such use is at least as protective of public health as is disposal
of phosphogypsum in mines or stacks."114
111 Moissct, J., Location of Radium in Phosphogypsum and Improved Process for Removal of Radium from Phosphogypsum.
PJatres Lafarge (France) (date not known).
m Palmer, J.W. and J.C Gaynor, Method for Solidifying Waste Slime Suspensions. U.S. Patent 4,457,781 to USG Corporation,
July 3, 1984, p. 4.
113 54 FR 51654, December 15, 1989.
114 55 FR 13482, April 10,1990.
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12-42 Chapter 1.2: Phosphoric Acid Production
With respect to these four regulatory options, this report does not discuss options (1) or (3), other
than to say that option (1) would preclude all of the alternative uses, with the possible exception of mine
reclamation, and that it is unlikely that the option (3) would result in a significant reduction in the amount
of phosphogypsum requiring disposal in mines or stacks.
Utilization of Phosphogypsum in Agriculture
Description
Phosphogypsum has been used in agriculture as a source of calcium and sulfur for soils that are
deficient in these elements. Phosphogypsum is also incorporated into soils in order to provide sediment
control for soils that have been eroded and leached to the point where they have developed a compacted crust.
In addition, phosphogypsum is sometimes incorporated into acidic soils to serve as a buffering agent.
Phosphogypsum is sometimes pelletized before being applied to the soil, though the majority of
phosphogypsum used for agricultural purposes is taken directly from disposal stacks, transported to local
fertilizer companies, and distributed to the farmers. When the phosphogypsum is used as a fertilizer it is
simply spread on the top of the soil, whereas when it is used for pH adjustment or sediment control it is tilled
into the soil.
Current And Potential Use
It is estimated that 1,260,000 metric tons of gypsum are used in agriculture each year.115 Of this
amount, approximately 221,000 metric tons is from phosphogypsum stacks, 318,000 metric tons is from by-
product gypsum processors, and 721,000 metric tons is from natural gypsum mines and quarries..116
As discussed above, EPA currently requires that phosphogypsum be disposed in stacks or mines,
although a limited class waiver for agricultural use of phosphogypsum is in effect until October 1,1990. After
October 1, 1990, agricultural uses of phosphogypsum will not be allowed unless EPA decides to implement
regulatory options (2) or (4) identified above.
If a threshold level of radium-226 is established (regulatory option (2)), it may be possible to utilize
the puosphogypsum after purification (i.e., reducing the radium-226 content) (see section 12.5.1). If the
physical separation method described in section 12.5.1 were used to purify phosphogypsum, the data displayed
in Exhibits 12-7 and 12-8 suggest that some of the phosphogypsum generated in the states of Florida, Idaho,
Louisiana, Mississippi, North Carolina, and Texas might have a radium-226 content below the threshold level
of 10 pCi/g. However, the available data are not detailed enough for EPA to estimate how much of the
purified phosphogypsum at each facility would fall below the threshold level. If either of the acid digestion
purification methods (see section 12.5.1) were used to purify the phosphogypsum, the data in Exhibits 12-8
and 12-9 suggest that all of the phosphogypsum generated in the U.S. would have radium-226 concentrations
below the threshold level.
Factors Relevant to Regulatory Status
A1978 radiological assessment of the application of phosphogypsum to vegetable crop land concluded
that there is little reason for concern regarding potential radiological hazards from the uptake of radium-226
by vegetable plants grown in soils treated with phosphogypsum.
115 McElroy, Christopher J., Petition of United States Gypsum Company for Partial Reconsideration and Clarification, and
Opposition of United States Gypsum Company to the Petition for Partial Reconsideration and Request for Slav of the Fertilizer
Institute, United Slates Gypsum Company, February 9,1990.
116 Ibid.
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Chapter 12: Phosphoric Acid Production 12-43
In a different study, data on the radium-226 content of phosphogypsum samples from Florida and
Idaho were used to calculate the increase in radium.-226 content of soil to which phosphogypsum is applied.
The study found that the application of 1 metric tons of 40 pCi/g phosphogypsum to 1 hectare of land, and
mixed in the soil to a depth of 20 cm, would increase the radium-226 content of the soil by 0.01538 pCi/g.
Therefore, the application of phosphogypsum for the purpose of sulfur fertilization (assuming an application
rate of 0.1 metric tons per hectare per year) would result in an increase in the soil's radium-226 content of
0.0015 pCi/g-year, while the application of phosphogypsum for the purpose of sediment control (assuming an
application rate of 4.0 metric tons per hectare per year) would result in an increase in the soil's radium-226
content of 0.62 pCi/g-year. Over a period of 100 years, these application rates would cause radium-226
concentrations to increase by 0.15 and 6.2 pCi/g, respectively, as compared to the typical radium-226 content
in soils of 1-2 pCi/g.117
Feasibility
It is uncertain whether future regulations will completely preclude the agricultural uses of
phosphogypsum, or only limit when and how it may be used.118 Since many fanners have continued to use
phosphogypsum despite the prospect of new regulatory prohibitions, and concerns about the radium-226 found
in phosphogypsum,119 it is not unreasonable to assume that fanners would continue to use it in the future,
if it remains economically competitive. However, if it becomes necessary to reduce the radium-226 content
before it can be used, the additional costs are likely to reduce the amount of phosphogypsum used if
purification would make phosphogypsum more expensive than the materials it competes with.
Utilization of Phosphogypsum for Mine Reclamation
Description
An alternative to the direct disposal of phosphogypsum in stacks and/or mines has been developed
in which phosphogypsum is mixed with phosphatic clay suspension (a waste stream from the beneficiation of
phosphate rock), and placed in a disposal site (generally the phosphate mine) where it consolidates and can
be reclaimed by planting grass and trees.120 The process begins by increasing the solids content of the
phosphatic clay suspension to 10 percent; a portion of the dewatered clay is pumped to the phosphoric acid
plant and mixed with phosphogypsum from the belt-filters; the clay-phosphogypsum mixture (blend) is put into
a blend tank and additional phosphogypsum from the stacks and phosphatic clay suspension are added until
there are approximately 3 parts phosphogypsum to 1 pan clay, the resulting blend (35 percent solids) is
pumped as a slurry to the disposal site; and after the blend has had approximately one year to dewater and
consolidate, it is possible to plant grass and trees on the surface.121
117 Burau, R.G., Agricultural Impact of Radium-226 in Gypsum Derived from Phosphate Fertilizer Manufacture. October 1976.
118 55 FR 13482 April 10, 1990.
119 Personal communication, Dr. Gary Gascho, University of Georgia Experiment Station, April 25,1990.
120 Palmer, Jay W. and AP. Koulobcris, Slimes Waste Solidification with Hvdralable Calcium Sulfate. paper to be presented at
the University of Miami Civil Engineering Department Seminar on Phosphogypsum on April 25-27,1984, p. 279.
121 Personal communication, William A Scrumming, Environmental Affairs Manager, Texasgulf Inc., April 30, 1990.
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12-44 Chapter 12: Phosphoric Acid Production
Current and Potential Use
Only Texasgulf s facility in Aurora, North Carolina is known to be using this management practice.
Tb date, Texasgulf has used the phosphogypsum-clay blend to reclaim a 400 acre122 portion of a phosphate
mine adjacent to the facility, and is currently utilizing phosphogypsum at about the same rate as it is being
generated.123
In considering whether any of the other 18 facilities could utilize their phosphogypsum in this way,
there are at least two factors which need to be considered. The first factor is that the phosphoric acid plant
be located near enough to the disposal site to keep transportation costs to a minimum. The second factor is
that the phosphatic clay suspension contain sufficient base (e.g., calcium carbonate) to neutralize the acids in
the phosphogypsum. Some of the facilities in Idaho and Florida may be close enough to their mines to utilize
their phosphogypsum (total of 45,777,691 metric tons in 1988)124 for mine reclamation, although this is not
at all certain. The facilities in Louisiana, Mississippi, and Texas could not use this option to utilize their
phosphogypsum (8,911,000 metric tons in 1988)125 because their phosphate rock is mined in central Florida,
nor could the Chevron Chemical facility in Rock Springs, Wyoming (836,000 metric tons phosphogypsum in
1988),126 because its phosphate rock is mined in Utah. EPA does not know whether any of the phosphatic
clay suspensions generated outside of North Carolina are sufficiently basic to neutralize the acids in the
phosphogypsum.
Factors Relevant to Regulatory Status
EPA believes that the utilization of phosphogypsum to reclaim mines may have a number of
advantages over the current practice of placing it in stacks or mines. Specifically, having grass and trees
growing over the reclaimed mine will reduce the potential for the waste to be released to surface water by
erosion, or to the atmosphere as wind blown dust. It should also reduce the demand for surface
impoundments needed for the disposal of phosphatic clay suspension. Finally, the reclaimed disposal sites will
be more aesthetically pleasing than the stacks and mines currently used to dispose phosphogypsum. While
there are no obvious disadvantages, contaminant releases from areas reclaimed in this manner, particularly to
ground water is a potential problem. EPA has not found any information regarding the migration of
hazardous constituents from the phosphogypsum-clay blend into ground or surface waters.
The radiological and chemical composition of the phosphogypsum-clay blend will vary widely, due to
differences in phosphate ore and manufacturing processes. Texasgulf believes that its phosphogypsum-clay
blend has approximately the same radionuclide concentrations as the original phosphogypsum.127 This
belief is consistent with data from central Florida in which the concentration of radium-226 is 23.8 pCi/g in
phosphatic clay suspensions, and 25.9 pCi/g in the phosphogypsum.128 While not much data on the
chemical, radiological, or physical characteristics of the phosphogypsum-clay blend is currently available, North
Carolina State University's, Department of Soil Science is reportedly in the process of investigating these
issues.12'
m The filled area was approximately 35 feet deep.
125 Schimming, oj>. cit.
124 Ibid.
125 Company responses to EPA's "National Survey of Solid Wastes from Mineral Processing Facilities,' conducted in 1969.
126 Ibjd.
127 Schimming, og. at.
m Palmer, J.W. and A.P. Kouloheris, Slimes Waste Solidification with HvdrataMe Calcium Sulfate. Paper to have been presented
at the University of Miami Civil Engineering Department Seminar on Phosphogypsum, April 25-27,1984, p. 278.
129 Schimming, og. cit.
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Chapter 12: Phosphoric Acid Production 12-45
Feasibility
It is likely that this management alternative will have a greater level of social acceptability than
current practices, which result in large, barren disposal areas. EPA does not believe that the rule requiring
that phosphogypsum be disposed in stacks or mines (thereby precluding alternative uses of the material) will
preclude the use of this alternative, since it does not involve putting the phosphogypsum-clay blend anywhere
except in stacks and mines.130 The greatest barriers to the use of this alternative appear to be geographic
and technical in nature (see the discussion on Current and Potential Use), although there may also be some
economic barriers (e.g., current practices are less expensive).
Utilization of Phosphogypsum in Construction Materials
Phosphogypsum can be utilized as a construction material in a variety of ways. The two major areas
of use are in building materials and highway construction. This section describes and evaluates applications
in both areas.
Description
Phosphogypsum has the same basic properties as natural gypsum and may be used as a substitute for
natural gypsum in the manufacture of commercial construction products. Approximately 70 percent of the
natural gypsum used in the U.S. is for the manufacture of gypsum board or partition panels. Another 19
percent is used as an additive to cement. Addition of natural gypsum to cement retards the setting time,
counteracts shrinkage, speeds the development of initial strength, and increases long-term strength and
resistance to sulfate etching. The remaining 11 percent of all natural gypsum use is attributable to agricultural
uses (7 percent) and miscellaneous uses including the manufacture of plaster and cement.131
Phosphogypsum generated from the classic Prayon process for phosphoric acid production must be purified
by removing phosphates, fluorides, and other impurities for it to be successfully used in the production of
building materials or as an additive to cement, whereas phosphogypsum from the Central-Prayon, Nissan-H,
and Nissan-C processes may often be used directly as natural gypsum substitutes without the need for
purification.
Phosphogypsum from all four processes may often be used in the manufacture of cement without
additional purification. One of the most promising processes for utilizing phosphogypsum in the manufacture
of portland cement is the OSW-Krupp process, a modification of the Mueller-Kiihne process. In this process,
phosphogypsum is dried in a rotary dryer and mixed with coke, sand, and clay. The mixture is then ground,
pelletized, and fed to a rotary kiln where SO2 and clinker are formed. The SO2 can then be passed to an acid
conversion plant to produce HjSO^ which may be recycled to the phosphoric acid production process. The
clinker is cooled and metered along with natural gypsum onto a belt conveyor feeding into a finished cement
mill.132
Phosphogypsum generated from all phosphoric acid production processes may be used successfully
as a road base, when stabilized with 5-10 percent portland cement or 15-25 percent fly ash, mixed with granular
soil and compacted for secondary road construction, used in a portland cement concrete mixture and
compacted to form roller-compacted concrete for paving driveways and parking areas, or used as fill and sub-
base material.133-134
130
54 FR 51654 December 15,1989.
131 Chang, W.F. and Murray I. Mantel), Engineering Properties and Construction Applications of Phosphogvpsum. Phosphate
Research Institute, University of Miami Press, Coral Gables, Florida, 1990, p. 6.
U2 Zellars-Williams Company, A.P. Kouloheris, principal investigator, Evaluation of Potential Commercial Processes for the
Production of Sulfuric Acid From Phogphogvpsum. Publication No. 01-002-001, Florida Institute of Phosphate Research, October
1981, pp. 18, 22.
133 Ibid., pp. 177-189.
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12-46 Chapter 12: Phosphoric Acid Production
Current and Potential Uses
Currently, there are no major uses of phosphogypsum in the U.S. in the manufacture of building
materials or in highway construction due to the low- cost availability of other suitable materials and to the
ban on utilization of phosphogypsum under 40 CFR part 61, subpart R, National Emission Standards for
Hazardous Air Pollutants, Radon Emissions from Phosphogypsum Stacks.
The U.S. has led the world in the mining of natural gypsum, with 20 percent of total world output.
The cost of purifying and dewatering phosphogypsum and the relative abundance of natural gypsum has
historically discouraged the development of phosphogypsum as a replacement for gypsum in the manufacture
of building materials in the U.S.135 It is unlikely that there will be a significant increase in the utilization
of phosphogypsum in this capacity as long as there is a relatively abundant, low-cost supply of natural gypsum
in the U.S.
Utilization of phosphogypsum in the production of H2SO4 and cement clinker would be possible in
Florida. This application is most feasible where there is a shortage of sulfur and a high demand for cement.
Its potential for success in Florida depends upon the sulfur market and the ability of a fertilizer company to
market the cement clinker produced.136
Phosphogypsum has been successfully used on an experimental basis for paving and highway
construction in both Texas and Florida. Phosphogypsum from Mobil's facility in Pasadena was stabilized with
fly ash or portland cement and used as a road base on five test sections of city streets in La Porte, Texas.137
In Polk County, Florida, the use of phosphogypsum as road base was demonstrated on a 2.4 km (1.5 mile)
stretch of road, where it was mixed with granular soil and compacted prior to installation.138 Another
demonstration of using phosphogypsum as a road base occurred in Columbia County, Florida, where both 100
percent dihydrate phosphogypsum and mixtures of phosphogypsum-sand were used in a 2 mile stretch of
road.139 Phosphogypsum was also used as a component (13 percent) of roller-compacted concrete, which
was used to pave 2,000 square yards of driveways and parking areas at the Florida Institute of Phosphate
Research in Bartow, Florida.140
The actual commercial use of phosphogypsum as a road sub-base material has been demonstrated on
a small scale in both Florida and North Carolina. In Florida it was used as sub-base roads at phosphorous
processing facilities in central Florida, and as limestone substitute in the road sub-base of a section of blacktop
road. In North Carolina it has been used as fill and sub-base in roads crossing swampy areas.141
Factors Affecting Regulatory Status
The primary regulatory concerns with respect to the disposal and utilization of phosphogypsum stem
from its radium-226 content The radium-226 is of sufficient concern that EPA currently requires
phosphogypsum to be disposed of in a stack or mine, thereby precluding all of the construction uses discussed
^(...continued)
134 Collins, R J. and R.H. Miller, Availability of Mining Wattes and Their Potential for Use as Hiehwav Material - Volume I:
Classification and Technical and Environmental Analysis. FHWA-RD-76-106, prepared for Federal Highway Administration, May
1976, p. 146.
us Fitzgerald, J.E., Jr. and Edward L. Scnsinutfar, "Radiation Exposure from Construction Materials Utilizing Byproduct Gypsum
from Phosphate Mining", (date not known), p. 353.
136 Kouloheris, oj>. tit., p. 16.
137 Chang, 0£. cjt., p. 177.
138 Ibid., p. 178.
09 Ibid., p. 183.
140 Ibid., pp. 186-187.
141 Collins, 0£. tit. p. 146.
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Chapter 12: Phosphoric Acid Production 12-47
above. As is discussed at the beginning of this section, EPA is currently considering a number of regulatory
options, two of which could conceivably allow phosphogypsum to be utilized in construction.
If a threshold level of radium-226 is established (regulatory option (2)), it may be possible to utilize
the phosphogypsum after purification (i.e., reducing the radium-226 content) (see section 12.5.1). Assuming
that the proposed threshold level of 10 pCi/g were adopted, and the physical separation method described in
section 12.5.1 were used to purify the phosphogypsum, the data displayed in Exhibits 12-7 and 12-8 suggest
that some of the phosphogypsum generated in the states of Florida, Idaho, Louisiana, Mississippi, North
Carolina, and Texas might have a radium-226 content lower than the threshold value of 10 pCi/g. However,
the available data are not detailed enough for EPA to estimate how much of the purified phosphogypsum
would contain less radium-226 than the threshold level, or if phosphogypsum with a sufficiently low radium-
226 concentration would be close enough to the potential markets for it to be economically competitive.
Similarly, if one of the acid digestion purification methods (see section 12.5.1) were used to purify the
phosphogypsum, the data in Exhibits 12-7 and 12-8 suggest that all of the phosphogypsum generated in the
U.S. would have radium-226 concentrations lower than the threshold level.
It is not clear whether adoption of the fourth regulatory option would preclude the use of
phosphogypsum in construction materials. It is likely that the determination of whether a particular use of
phosphogypsum is at least as protective of human health and the environment as phosphogypsum disposal in
stacks or mines, would have to be made on a case by case basis.
Feasibility
Even if it is allowed by the regulations, it is uncertain whether a significant amount of phosphogypsum
would be utilized as a construction material. The basis for this conclusion is that even before the current
constraints on the utilization of phosphogypsum were imposed, very little phosphogypsum has been used in
construction; consumer concern over indoor radon is likely to discourage the use of products made from
phosphogypsum, which may be perceived as a significant source of radon even if purified; natural gypsum is
readily available in most parts of the U.S.; and there is concern about the exposure (e.g., via leaching and
subsequent ingestion, see section 12.3.1) of humans to the hazardous constituents in phosphogypsum.
12.6 Cost and Economic Impacts
Section 8002(p) of RCRA directs EPA to examine the costs of alternative practices for the
management of the special wastes considered in this report. EPA has responded to this requirement by
evaluating the operational changes that would be implied by compliance with three different regulatory
scenarios, as described in Chapter 2. In reviewing and evaluating the Agency's estimates of the cost and
economic impacts associated with these changes, it is important to remember what the regulatory scenarios
imply, and what assumptions have been made in conducting the analysis.
The focus of the Subtitle C compliance scenario is on the costs of constructing and operating
hazardous waste land disposal units. Other important aspects of the Subtitle C system (e.g., corrective action)
have not been explicitly factored into the cost analysis. Therefore, differences between the costs estimated for
Subtitle C compliance and those under other scenarios (particularly Subtitle C-Minus) are less than they might
be under an alternative set of conditions (e.g., if most affected facilities were not already subject to Subtitle C).
The Subtitle C-Minus scenario represents, as discussed above in Chapter 2, the minimum requirements that
would apply to any of the special wastes that are ultimately regulated as hazardous wastes; this scenario does
not reflect any actual determinations or preliminary judgments concerning the specific requirements that would
apply to any such wastes. Further, the Subtitle D-Plus scenario represents one of many possible approaches
to a Subtitle D program for mineral processing special wastes, and has been included in this report only for
illustrative purposes. The cost estimates provided below for the three scenarios considered in this report must
be interpreted accordingly.
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12-48 Chapter 12: Phosphoric Acid Production
In accordance with the spirit of RCRA §8002(p), EPA has focused its analysis on impacts on the firms
and faculties generating the special wastes, rather than on net impacts to society in the aggregate. Therefore,
the cost analysis has been conducted on an after-tax basis, using a discount rate based on a previously
developed estimate of the weighted average cost of capital to U.S. industrial firms (9.49 percent), as discussed
in Chapter 2. Waste generation rate estimates (which are directly proportional to costs) for the period of
analysis (the present through 1995) have been developed in consultation with the U.S Bureau of Mines.
In this section, EPA first outlines the way in which it has identified and evaluated the waste
management practices that would be employed under different regulatory scenarios by facilities producing wet
process phosphoric acid. Next, the section discusses the cost implications of requiring these changes to existing
waste management practices. The last part of the section discusses and predicts the ultimate impacts of the
increased waste management costs faced by the affected facilities.
12.6.1 Regulatory Scenarios and Required Management Practices
Because the available data indicate that process wastewater and phosphogypsum may exhibit the
hazardous waste characteristics of EP toxicity and/or corrosivity, these materials would in many cases be
regulated as hazardous wastes under RCRA Subtitle C were it not for the the Mining Waste Exclusion. A
decision by EPA that Subtitle C regulation is appropriate for these wastes would therefore result in
incremental waste management costs. Accordingly, the Agency has estimated the incidence, magnitude, and
impacts of these costs for the facilities that generate process wastewater and phosphogypsum from wet process
phosphoric acid production; this analysis is presented in the following paragraphs.
EPA has adopted a conservative approach in conducting its cost analysis for the wastes generated by
the phosphoric acid sector. The Agency has assumed that process wastewater would exhibit EP toxicity and
corrosivity at all facilities unless actual sampling and analysis data demonstrate otherwise; EPA's waste
sampling data, indicate that process wastewater exhibits at least one characteristic of hazardous waste at all
facilities from which sampling data are available. Furthermore, because of current co-management of process
waters at phosphoric acid facilities, the Agency has assumed that all process wastewaters managed at the
facilities have similar chemical characteristics, that is, all circulating process water is assumed to be corrosive
and/or EP toxic. In reality, the aggregate process wastewater stream may be separated into different process
streams; only those that are potentially hazardous would require treatment. EPAs estimated compliance costs
for managing process wastewater may, therefore, be overstated.
Similarly, in following a conservative approach, the Agency has assumed that phosphogypsum would
exhibit EP toxicity at all faculties unless actual sampling and analysis data demonstrate otherwise. EPAs waste
sampling data indicate that EP toxicity is not exhibited at 10 of facilities that generate the material; the
Agency's cost and impact analysis of phosphogypsum management is, therefore, limited to eleven facilities, only
one of which was both sampled and at which phosphogypsum constituent concentrations exceed one or more
of the EP toxicity regulatory levels.
The Agency has estimated the costs associated with Subtitle C regulation, as well as with two
somewhat less stringent regulatory scenarios, referred to here as "Subtitle C-Minus" and 'Subtitle D-Plus" (a
more detailed description of the cost impact analysis and the development of these regulatory scenarios is
presented in Chapter 2, above). In the following paragraphs, EPA discusses the assumed management
practices that would occur under each regulatory alternative.
Process Wastewater
Subtitle C
Under Subtitle C standards, hazardous waste that is managed on-site must meet the standards codified
at 40 CFR Parts 264 and 265 for hazardous waste treatment, storage, and disposal facilities. The Agency has
assumed that the process wastewater and the phosphogypsum can and will be managed separately; non-
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Chapter 12: Phosphoric Acid Production 12-49
hazardous process water is assumed to be used to transport the phosphogypsum to the management unit.
Because phosphoric acid production process wastewater is a dilute, aqueous liquid, that is usually corrosive
and often EP toxic, the management practice of choice under Subtitle C is treatment (neutralization and/or
metals precipitation). The scenario examined here involves construction of a Subtitle C surge pond (double-
lined surface impoundment) which feeds a system of concrete impoundments in which treatment is performed.
Following treatment, the effluent may be reused by the facility (e.g., to slurry fluorogypsum to the gypsum
stack or impoundment) just as it is under current practice. The sludge is assumed to be non-hazardous and
is assumed to be disposed of in an unlined disposal impoundment or landfill.
Subtitle C-Minus
Assumed practices under Subtitle C-Minus are identical to those described above for the full
Subtitle C scenario, with the exception that some of the requirements for construction and operation of the
hazardous waste surge pond have been relaxed, most notably the liner design requirements.
Subtitle D-Plus
Assumed practices under Subtitle D-Plus are identical to those described above for the Subtitle C-
Minus scenario. Generators of process wastewaters are assumed to pose either moderate or high risk to
ground water, even if, as is true in one case in the phosphoric acid sector, the environmental conditions
indicate a low risk. Therefore, all facilities meet the same requirements under both Subtitle D-Plus and under
Subtitle C-Minus; ground-water monitoring, a practice that is not required under the low risk Subtitle D-plus
scenario, is assumed to be required in all cases.
Phosphogypsum
Subtitle C
Under Subtitle C standards, of hazardous waste that is managed on-site must meet the standards
codified at 40 CFR Parts 264 and 265 for hazardous waste treatment, storage, and disposal facilities. The
Agency has assumed that the phosphogypsum can and will be managed separately from the other special waste,
process wastewater; non-hazardous process wastewater is assumed to be used to transport the phosphogypsum
to the management unit. Because phosphogypsum is an inorganic solid that is transported in slurry form, the
management practice of choice under Subtitle C is surface impoundment disposal. EPA has determined that
because of Subtitle C closure requirements, existing waste management units (gypsum stacks) would not be
permissible, because of the steep (nearly vertical) angles with which they are constructed. Closure of such
units would require extensive contouring and regrading (so that they could be capped effectively), such that
the total area occupied by the unit at closure would greatly exceed the space occupied during its operating life.
The scenario examined here involves construction of a double-lined Subtitle C surface impoundment of
significant size. The gypsum would be slurried to this impoundment in much the same way as it is currently
slurried to gypsum stacks. Following settling of the suspended phosphogypsum, the transport water would be
removed and piped back to the process operation for reuse, just as it is under current practice.
Subtitle C-Minus
Two primary differences are assumed to exist between full Subtitle C and Subtitle C-minus. The first
is the assumption that facilities could use gypsum stacks if their use is less costly than using disposal
impoundments. The second difference is the facility-specific application of tailored requirements based on
potential risk to groundwater at affected facilities. Under the C-Minus scenario, as well as the Subtitle D-Plus
scenario described below, the degree of potential risk of contaminating ground-water resources was used as
a decision criterion in determining what level of protection (e.g., liner and closure cap requirements) would
be necessary to protect human health and the environment. Ten of the 11 facilities assumed to generate
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12-50 Chapter 12: Phosphoric Acid Production
potentially hazardous phosphogypsum were determined to have a high potential to contaminate ground-water
resources; the eleventh was considered a low risk location.
When risk to ground water is high, facilities are assumed to be required to manage the waste in stacks
lined with double synthetic liners and leachate collection and detection systems. As none of the ten facilities
in high risk locations currently operate this type of unit, all would, under Subtitle C-minus, be required to
build new stacks. In addition to the double composite liners, the stacks in high risk locations are required to
have run-on/run-off controls and ground-water monit ring wells; both practices must be continued through
the post-closure care period. In addition, the units must undergo formal closure, including a cap of topsoil
and grass over a composite liner. Post-closure care must be maintained (e.g., mowing and general cap
maintenance, and ground-water monitoring) for a period of 30 years.
At three of the ten facilities, where depth to groundwater allows for relatively deep impoundment
construction, surface impoundment disposal of phosphogypsum is estimated to be the least cost management
alternative. Composite-lined impoundments, requiring composite caps at closure, were assumed to be used
at these facilities.
Chevron's Wyoming facility, the only facility in a low risk area (and the only facility at which
phosphogypsum samples were determined to be EP toxic) was allowed to continue using its currently operating
unit; the operator was assumed, however, to be required to install a ground-water monitoring system.
Subtitle D-Plus
As under both Subtitle C scenarios, facility operators under the Subtitle D-Plus scenario would be
required to ensure that hazardous contaminants do not escape into the environment. Like the Subtitle C-
Minus scenario, facility-specific requirements are applied to allow the level of protection to increase as the
potential risk to ground water increases. Under Subtitle D-Plus, the facilities are also allowed to operate
gypsum stacks. The stacks do not require capping at closure under this scenario, under the assumption that
the natural crusting of the gypsum that occurs as the material dries would be adequately protective. Because
no capping, and therefore, no reduced slope angles, are required, the stacks are built with the same dimensions
as the currently operating stacks, minimizing the total basal area required and, therefore, potentially decreasing
the cost of compliance. Stacks at the ten high-risk facilities are assumed to require composite liners, single
leachate collection systems, and ground-water monitoring. The one low-risk facility is assumed to continue
operating its current stack. All eleven facilities are assumed to be required to install run-on/run-off controls
and would continue the practice through the post-closure care period.
12.6.2 Cost Impact Assessment Results
Process Wattewater
Results of the cost impact analysis for the process wastewater generated by phosphoric acid facilities
are presented by facility and regulatory scenario in Exhibit 12-9. Of the 21 facilities generating process
wastewater, all are expected to incur costs under the Subtitle C regulatory scenario. Under this scenario, the
annualized regulatory compliance costs would be $3.2 to S26.3 million greater than the baseline waste
management costs, with a sector total of $225 million per year over baseline costs. Annualized new capital
expenditures range from $1.1 to 11.7 million with a sector total of $101.8 million. At the majority of the
facilities, capital costs account for 45 percent of the total annualized compliance cost, with the cost of
wastewater tank treatment dominating overall costs.
Under the Subtitle C-Minus and D-Plus scenarios, the annualized compliance costs drop only slightly,
due to relaxed technical standards for operation of the surge ponds used to hold the wastewater prior to
treatment. Annualized compliance costs under Subtitle C-Minus range from $3.0 to $25.6 million; the sector
total is estimated to be $215 million. Annualized costs under Subtitle D-Plus are nearly identical, with a
-------
Exhibit 12-9
Compliance Cost Analysis Results for Management of
Process Wastewater from Phosphoric Acid Production^
Facility
Agri Chem - Bartow. FL
Agrico Chemical - DonaJdsonvllle. LA
Agrico Chemical - Mulberry. FL
Agrico Chemical - Uncle Sam. LA
Arcadian - Gelsmar LA
Central Phosphate* - Plant City. FL
CF Chemical* - Bartow, FL
Chevron - Rock Spring*. WY
ConMrv - Nichols, FL
Farmland Industrie* - Bartow. FL
Oardlnler - Rrvervlew. FL
IMC Fertilizer - Mulberry. FL
Mobil Mining - Pa*ad*na. TX
Nu-South Industrie* - Pascagoula. MS
Nu-W**t - Soda Spring*. ID
Occidental Chemical - White Springs. FL
Royster • Mulberry. FL
Royster - Palmetto. FL
Semlnole Fertilizer - Bartow. FL
JR Slmptot - Pocatello. ID
TexasguH - Aurora. NC
Total:
Average:
Ba**tlne Wast*
Management
Cost
Annual Total
($000)
296
287
296
314
247
320
800
281
261
285
835
326
276
519
269
824
524
549
520
555
303
8.697
424
Incremental Costs of Regulatory Compliance
Subtitle C
Annual
Total
($000)
5,849
12,131
11,098
15,541
5.375
22,313
6.950
4,760
3.213
6.817
16.544
26.309
8.023
7.871
5.743
12.789
6,506
10.719
12.948
5.369
18.166
225.033
10.716
Total
Capital
($000)
15.488
39.213
32,239
50,321
16,180
68,915
19,436
12,439
8,004
18.332
51.094
79.067
24.179
26.091
16,424
36,856
17,902
36.137
37.186
14.958
62,169
682,629
35.506
Annual
Capital
($000)
2,311
5.851
4.811
7.509
2.414
10.283
2.900
1.856
1.194
2.735
7.624
11,798
3.608
3.893
2.451
5.499
2.671
5.392
5.549
2.232
9.276
101,857
4.650
Subtitle C-MInu*
Annual
Total
($000)
5.537
11.677
10,654
14.975
5.162
21,080
6.610
4.504
3.048
6,465
15.633
25,619
7,638
7.491
5.464
12.256
6,192
10,197
12,434
5,093
17,393
215.121
10.244
Total
Capital
($000)
13,781
36.708
29.795
47,193
15,022
62.058
17.578
11.043
7.110
16.399
46.047
75.236
22.068
24,013
14.899
33.912
16,183
33.262
34.356
13.452
57.893
628,007
29,905
Annual
Capital
($000)
2.056
5.477
4.446
7,042
2.241
9.260
2.623
1.648
1.061
2.447
6.871
11.226
3.293
3.583
2.223
5.060
2.415
4.963
5.126
2.007
8.638
93.706
4,462
Subtitle D Plu*
Annual
Total
($000)
5,434
11,677
10.551
14,872
5.059
21.080
6,507
4.402
2.946
6.362
15.530
25.516
7.535
7.388
5.361
12.153
6.069
10.094
12.331
4.990
17.290
213,167
10,151
Total
Capital
($000)
13.781
36.708
29.795
47.193
15.022
62,058
17,576
11,043
7.110
16,399
46,047
75,236
22.068
24.013
14.899
33.912
16.183
33,262
34.356
13.452
57,893
628,007
29.905
Annual
Capital
($000)
2.056
5,477
4,446
7,042
2,241
9,260
2,623
1,648
1,061
2,447
6,871
11.226
3,293
3,583
2,223
5,060
2,415
4,963
5,126
2,007
8,638
93.706
4.462
(a) Value* reported In this table are those computed by EPA's cost estimating model and are included for Illustrative purposes. The data, assumptions, and computalional
methods underlying these values are such that EPA believes that the compliance cost estimates reported here are precise to two significant figures.
Facilities evaluated here as generating potentially hazardous waste include those for which no sampling data exists.
-------
12-52 Chapter 12: Phosphoric Acid Production
sector total estimated at S213 million; the slight difference is due to differences in assumed permitting
requirements and associated costs.
Phosphogypsum
Results of the cost impact analysis for the phosphogypsum generated by phosphoric acid producers
are presented by facility and regulatory scenario in Exhibit 12-10. Of the 21 facilities generating
phosphogypsum, a maximum of 11 may generate potentially hazardous waste and incur costs under the
Subtitle C regulatory scenario. Under this scenario, the annualized regulatory compliance costs would range,
for those eleven facilities, from $10.8 million to $185 million over and above baseline waste management costs,
with a sector total of $684 million per year. Annualized new capital expenditures account for the vast majority
(80 percent) of incremental costs, ranging from $8.4 million to $147 million greater than baseline, with a sector
total of $542 million. The primary reason for these extreme compliance-related capital expenditures is the
large size of the Subtitle C disposal impoundments that would be needed to contain a 15 year accumulation
of phosphogypsum at most facilities.
Under the less rigorous, risk related technical requirements of the Subtitle C-Minus scenario, the
annualized compliance costs would be $1.2 million to $65.3 million greater than the baseline waste
management costs, with a sector total of $216.7 million per year. Annualized new capital expenditures would
range from $0.4 to $51.2 million, with a sector total of $171 million. The decrease in compliance costs
between the two Subtitle C scenarios is primarily a function of the assumption that modified stacks could be
used under the Subtitle C-Minus scenario; the primary design modification involves a decrease in the slope
of the stacks to allow for effective capping at closure. In addition, facilities located in low risk areas (one in
this sector) could continue to operate their current stacks, and would simply be required to retrofit run-on/run-
off controls and install ground-water monitoring systems. Facilities in high risk areas (the remaining ten
facilities), incur higher costs due to requirements for double liners/leachate collection systems, increased basal
area due to limitations on slope, and capping at closure. For three facilities, the costs of building new stacks
that complied with these requirements were estimated to be higher than those of building similarly protective
disposal impoundments; accordingly, for costing purposes, these facilities were assumed to build impoundments
rather than gypsum stacks.
Under the Subtitle D-Plus regulatory scenario, the annualized compliance costs would be S0.48 to
$62.2 million greater than the baseline waste management costs, with a sector total of $48.7 million per year.
Annualized new capital expenditures would range from $0.1 to $52 million, with a sector total of S166 million.
The distribution of costs is identical to that of the C-Minus scenario, while the overall magnitude of the costs
is about 25 percent less. The primary reason for the decrease is that, because no capping is required, facilities
can operate stacks with slopes identical to current practices; this reduces the basal area needed and hence, the
costs of liners and leachate collection systems. In addition, the actual costs of capping are not incurred. As
under Subtitle C-Minus, the one facility located in a low risk area is assumed to continue operating its current
stack, but would retrofit needed controls. Ground-water monitoring is not required for this facility, due to
its low risk location.
12.6.2 Financial and Economic Impact Assessment
In order to evaluate the ability of affected facilities to bear these estimated regulatory compliance
costs, EPA performed an impact assessment which consists of three steps. First, the Agency compared the
estimated compliance costs to the financial strength of each facility, to assess the relative magnitude of the
financial burden that would be imposed in the absence of changes in supply, demand, or price. Next, EPA
conducted a qualitative evaluation of the salient market factors which affect the competitive position of the
phosphoric acid producers, in order to determine whether compliance costs could be passed on to labor
markets, suppliers of raw materials, or consumers. Finally, the Agency combined the results of the first two
steps to predict the net compliance-related economic impacts which would be experienced by the facilities
-------
Chapter 12: Phosphoric Acid Production 12-53
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12-54 Chapter 12: Phosphoric Acid Production
being evaluated. The methods and assumptions used in this analysis are described in Chapter 2 and in
Appendices E-3 and E-4 to this report.
Financial Ratio Analysis
Process Wasfewater
EPA believes that costs of compliance under full Subtitle C would have at least marginally significant
impacts on all 21 facilities, as reflected by the screening ratio results in Exhibit 12-11. Annual compliance
costs as a percent of value of shipments or value added are expected to be from one to five percent at 18 of
the 21 facilities; for the remaining facilities, the screening ratio results range from five to seven percent. The
compliance capital as a percent of annual sustaining capital is high for all 21 facilities, ranging from 14 to 73
percent. The financial impacts under prospective Subtitle C-Minus and D-Plus regulation would be similar
in distribution and magnitude to those of the Subtitle C scenario.
Phosphogypsum
Regulation under Subtitle C would have a highly significant financial impact on any phosphoric acid
facilities whose phosphogypsum is found to be hazardous (phosphogypsum was EP toxic at only one facility
that was sampled, therefore, the remaining ten facilities for which costs were estimated might or might not
actually experience impacts). As shown in Exhibit 12-12, the annualized incremental costs associated with
waste management under Subtitle C represent 4 to 40 percent of both the value added and the value of
shipments for all affected facilities generating potentially hazardous phosphogypsum. Moreover, the ratio of
annual capital costs to annual sustaining capital investments also suggests severe impacts for these facilities,
with screening ratio results ranging from 80 to 700 percent.
The financial impacts under Subtitle C-Minus regulation would be much less than under the full
Subtitle C scenario. One facility, located in a low risk area, is estimated to incur no impacts under Subtitle
C-Minus. Interestingly, this is the only facility for which waste sampling actually indicated EP toxicity. For
the remaining ten facilities, impacts on the value of shipments or value added range from 3 to 13 percent.
Estimation of impacts under the Subtitle D-Plus scenario indicates that for three of the ten affected
facilities, there is no difference from the Subtitle C-Minus scenario (the facility in the low risk area again
experiences no impacts). One of the remaining seven facilities experiences only slightly lower impacts (5
percent less than C-Minus); the remaining six facilities experience reductions in the magnitude of impacts of
43 percent from the C-Minus scenario. Annualized capital as a percent of sustaining capital investments is
high even under the Subtitle D-Plus scenario; screening ratio results for the ten affected facilities range from
55 to 229 percent.
Market Factor Analysis
Genera/ Competitive Position
The U.S. is the world's leading producer of phosphoric acid, the primary use of which is in fertilizers;
other uses for phosphoric acid include nutrient supplements for animal feeds, builders for detergents, water
softeners, additives for food, and pharmaceuticals. Domestic acid production is based on large quantities of
high-quality phosphate rock reserves, located principally in Honda and North Carolina. These deposits
provide abundant feedstock for high-quality phosphoric acid production. In recent years, Morocco has become
the United State's main competitor in international markets. This competition has resulted in a downward
price trend for phosphate in these markets. The fact that the U.S. is a major exporter of phosphate rock is
an indication of the quality and relative cost of its phosphate reserves. However, low-cost, high-quality
deposits do not guarantee profits in the phosphate rock and phosphoric acid markets. During difficult
economic times, the use of phosphoric acid can decline despite being offered at a fairly low price. Fertilizer
-------
Exhibit 12-11
Significance of Regulatory Compliance Costs for Management of
Process Wastewater from Phosphoric Acid Production^
Facility
Agrl Chwn - Bartow. FL
Agrlco Chemical - Donaldsonvllle, LA
Agrtco Chemical - Mulberry, FL
Agrlco Chemical - Uncle Sam. LA
Arcadian . Qefcmar, LA
Central Phoephatee - Plant City. FL
CF Chemical* • Bartow, FL
Chevron • Rock Springs, WY
Comerv • Ntohoto, FL
Farmland Industrie* - Bartow. FL
QMdlnlw - fflwvtaw, FL
IMC FertHlzef - Mulberry, FL
Moby Mining • PMadenn, TX
Nu-South Industrie* - Paacagoula. MS
Nu-We«t • Soda Spring*. IO
Occidental Chemical - White Spring*, FL
Royftar-Mulbany, FL
Royster - Palmetto. FL
Semlnole FanHfear • Bartow, FL
JR Slmptot - Pocatello. ID
TexasguH - Aurora, NC
SubtHle C
CC/VOS
1.69%
3.06%
3.37%
2.83%
3.67%
3.91%
0.32%
2.47%
1.77%
1.55%
4.07%
2.22%
349%
4.77%
2.61%
1.96%
2.47%
6.09%
2.91%
2.49%
2.01%
CC/VA
1.87%
3.40%
3.74%
3.14%
4.08%
4.34%
7.03%
2.75%
1.97%
1.72%
4.92%
2.46%
4.06%
5.31%
2.90%
2.20%
2.74%
6.76%
3.23%
276%
2.24%
IR/K
16.0%
35.5%
39.1%
32.8%
39.6%
43.2%
63.4%
23.1%
15.8%
14.9%
45.1%
23.9%
39.4%
56.7%
26.8%
20.5%
24.4%
73.6%
30.0%
24.8%
247%
Subtitle C-Mlnua
CC/VOS
1.60%
2.95%
3.23%
2.73%
3.53%
3.69%
6.02%
2.34%
1.68%
1.47%
3.65%
2.16%
3.48%
4.54%
2.49%
1.90%
2.35%
5.79%
2.80%
2.36%
1.93%
CC/VA
1.77%
3.28%
3,99%
3.03%
3.92%
4.10%
6.66%
2.60%
1.87%
1.63%
4.27%
2.40%
3.86%
5.05%
2.76%
2.11%
2.61%
6.43%
3.11%
2.62%
2.14%
IR/K
14.2%
33.2%
32.4%
30.6%
36,8%
38.9%
57.3%
20.5%
14.1%
13.4%
40.6%
22.7%
36.0%
52.2%
24.3%
18.8%
22.0%
67.7%
27,7%
22.3%
23.0%
Subtitle D-Plu*
CC/VOS
1.57%
295%
3.20%
2.71%
3.46%
3.69%
5.92%
2.28%
1.62%
1.45%
3.82%
2.15%
3.43%
4.48%
2.44%
188%
2.31%
5.73%
2.77%
231%
1.91%
CC/VA
1.74%
3.28%
3.56%
3.01%
3.84%
4.10%
6.58%
2.54%
1.80%
1 61%
4.25%
2.39%
3.81%
4.98%
2.71%
2.09%
2.57%
6.37%
3.08%
2.57%
2.13%
IR/K
14.2%
33.2%
32.4%
30.8%
36.8%
38.9%
57.3%
20.5%
14.1%
134%
40.6%
22.7%
360%
52.2%
24.3%
188%
22.0%
67.7%
27.7%
22.3%
230%
CC/VOS = Compliance Costs as Percent of Sales
CC/VA - Compliance Costa as Percent of Value Added
IR/K = Annualized Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported in this table are based upon EPA's compliance cost estimates. The Agency believes that these values are precise to two significant figures
Facilities evalauted here as generating potentially hazardous waste include those for which no sampling data exists.
-------
Exhibit 12-12
Significance of Regulatory Compliance Costs for Management of
Phosphogypsum from Phosphoric Acid Production*")
• Aclliiy
Agrl Chem • Bartow. FL
Agrteo Chemical - Mulberry. FL
Agrtco Chemical - Uncle Sam, LA
Central Phosphates - Plant CHy. FL
Chevron - Rook Springs, WY
Oardlnier - Rlvervlew. FL
MobH Mining - Pasadena. IX
Nu-South Industries - Pascagoula, MS
Nu-West- Soda Springe, ID
Occidental Chemical - White Springs. FL
Royaler - Palmetto, FL
CC/VOS
5.0%
12.6%
102%
32.4%
57%
28.8%
21.3%
37.9%
5.5*
4.3%
38.4%
Subtitle C
CC/VA
5.5%
13.9%
204M
36.0%
8.3%
32.0%
23.7%
42.1%
6.1%
4.8%
40.0%
IR/K
93.8%
239.8%
348.6%
618.2%
104.8%
548.1%
403.2%
718.5%
102.3%
82.8%
690.0%
Subtitle C-Mlnua
CC/VOS
3.4%
6.2%
11.9%
5.3%
0.7%
5.3%
5.9%
7.9%
3.7%
2.9%
7.6%
CC/VA
3.8%
6.9%
13.2%
5.9%
0.7%
5.9%
6.5%
8.8%
4.1%
3.3%
8.4%
IR/K
62.1%
120.6%
224.1%
103.3%
5.0%
101.0%
1112%
150.8%
67.0%
55.7%
143.9%
Subtitle D-Plua
CC/VOS
3.4%
3.6%
11.3%
3.1%
0.3%
3.1%
3.4%
4.5%
3.6%
2.9%
4.4%
CC/VA
3.7%
4.0%
12.6%
3.5%
0.3%
3.5%
38%
5.0%
4.0%
3.2%
4.8%
IR/K
66.2%
72.4%
229.8%
63.5%
1,6%
61.9%
65.3%
87.5%
67.0%
55.7%
845%
CC/VOS - Compliance Coats aa Percent of Sales
CC/VA - Compliance Costs as Percent of Value Added
IR/K - Annuallzad Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported In this table are based upon EPA's compliance cost estimates. The Agency believes that these values are precise to two significant figures.
Facilities evalauted here as generating potentially hazardous waste Include those for which no sampling data exists.
-------
Chapter 12: Phosphoric Acid Production 12-57
use is in part discretionary, and selection of types and amounts of various fertilizer types can vary. Despite
its fairly competitive position versus other world suppliers, therefore, the profit margins for phosphoric acid
and phosphate rock may often be somewhat restricted.
Throughout the 1990's, domestic production of phosphoric acid is expected to remain constant, while
foreign production is expected to increase by less than 2.5 percent per year. Both domestic and foreign
demand for phosphoric acid are expected to grow by less than 2.5 percent per year during the 1990's.
Potential tor Compliance Cost Pass-Through
Labor Markets. There has been considerable restructuring in the phosphate industry with some
associated wage concessions. The potential for further labor concessions is not known.
Lower Prices to Suppliers. The ability to pass through costs to input markets is not particularly
relevant because the major phosphoric acid producers are integrated.
Higher Prices. Higher prices are generally difficult to impose except during periods of worldwide
prosperity. The price of phosphate rock and phosphoric acid depends a great deal on competition from
Morocco, the price of alternative fertilizers, and the use of slow release fertilizers.
Evaluation of Cost/Economic Impacts
EPA believes that regulation of phosphogypsum as a hazardous waste under RCRA Subtitle C would
impose potentially severe impacts on facilities at which this waste exhibits EP toxicity, the number of such
facilities is highly uncertain but is at least one and likely to be two or three. Mitigation of the severe cost
impacts that would be experienced by the affected phosphoric acid producers under Subtitle C would be
unlikely, because of the limited potential for compliance cost pass-through (at least 10 of the 21 active
domestic producers would experience no impacts), and the operational reality that a substantial quantity
(approximately five tons) of phosphogypsum is generated for every ton of phosphoric acid produced using the
wet process. Therefore* EPA believes that regulation of phosphogypsum as a hazardous waste could pose a
threat to the continued operation of any producer whose phosphogypsum tested EP toxic. Regulation under
Subtitle C-Minus would also impose significant impacts at most facilities. The prospect of regulation of
phosphogypsum under the Subtitle D-Plus scenario examined here would be unlikely to pose a threat to the
continued viability of the majority of the phosphoric acid facilities. For 18 of the 21 active producers, no
significant impacts would be incurred in managing phosphogypsum under Subtitle D-Plus regulations. At least
three facilities, however, and one in particular, would be expected to incur significant impacts in managing
phosphogypsum even under Subtitle D-Plus, potentially posing a threat to the economic viability of these
facilities. One of those three facilities, however, is currently planning/constructing a new stack which is
expected to be lined and employ a leachate collection system; estimated costs in meeting Subtitle D-Plus
requirements may therefore actually have been incurred by that facility while this report was being prepared;
in that event, Subtitle D-Plus regulation would not impose any costs or impacts on this facility.
The Agency also expects that regulation of process wastewater as a hazardous waste under both
Subtitle C and C-Minus regulation could potentially pose a threat to the economic viability of affected
domestic phosphoric acid producers, based on estimated compliance cost impacts; estimated impacts under
the Subtitle D-Plus scenario are marginally lower. Because, however, all producers are expected to be affected,
there is a greater potential for passing through costs to consumers in the form of higher prices for domestically
produced acid than there would be if phosphogypsum were to be regulated as a hazardous waste. Eight of the
21 facilities managing potentially hazardous process wastewaters are predicted to incur significant impacts
under the Subtitle D-Plus scenario. The significance of these impacts, as discussed above, is diminished by
the possibility of the operators reducing waste generation or physically separating waste streams generated
-------
12-58 Chapter 12: Phosphoric Acid Production
from different operations, in order to dramatically reduce the actual volume of water that would be hazardous
and hence require treatment.
12.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) the potential for and documented
danger to human health and the environment; (2) the need for and desirability of additional regulation; and
(3) the costs and impacts of potential Subtitle C regulation.
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of phosphogypsum is moderate to high in comparison to other mineral processing
wastes studied in this report. Based on EP leach test results, 2 out of 28 samples (from 1 out of 8 facilities
tested) contain chromium concentrations in excess of the EP toxicity regulatory levels. Chromium
concentrations measured in SPLP (EPA Method 1312) leachate, however, were well below the EP regulatory
levels. Phosphogypsum contains 12 constituents that exceed one or more of the screening criteria used in this
analysis by more than a factor 10. Phosphogypsum solids may also contain uranium-238 and radium-226 in
concentrations that could pose an unacceptably high radiation risk if the waste is allowed to be used in an
unrestricted manner. For this reason, as pan of its recently promulgated airborne emission standards for
radionuclides (54 FR 51654, December 15, 1989), EPA has banned the off-site use or disposal of
phosphogypsum in anything other than a stack or mine, with a limited waiver for agricultural uses. (See also
55 FR 13480, April 10, 1990.)
The intrinsic hazard of phosphoric acid process wastewater is relatively high compared to other
mineral processing wastes studied in this report Measurements of pH in 42 out of 68 process wastewater
samples (from 10 of 14 facilities tested) indicated that the wastewater was corrosive, sometimes with pH values
as extreme as 0.5. Based on EP leach test results, 19 out of 30 samples contain cadmium concentrations in
excess of the EP toxicity regulatory level. In addition, 3 of 30 samples contain chromium concentrations in
excess of EP toricity regulatory levels. Phosphoric acid process wastewater also contains four constituents at
concentrations that exceed one or more of the screening criteria used in this analysis by more than a factor
of 1,000 and another 15 constituents exceed at least one relevant criterion by more than a factor of 10,
including three radionuclides (Le., gross alpha and beta radiation and radium-226).
Numerous documented cases of ground-water contamination indicate that phosphogypsum and process
wastewater constituents have been released to ground and surface water at a number of facilities, and, at some
sites, have migrated off-site to potable drinking water wells in concentrations that are well above criteria for
the protection of human health. For example, in central Florida, the State Department of Environmental
Regulation has initiated enforcement actions at all 11 active phosphoric acid production facilities because
phosphogypsum stacks and process wastewater ponds have caused ground-water contamination above drinking
water standards at the plant boundary or beyond. Based on the evidence of documented damages, EPA
concludes that management of phosphogypsum and process wastewater in stacks and unlined ponds can release
contaminants to the subsurface and that stack and dike failure can release contaminants to nearby surface
waters. The combination of the intrinsic hazard of these wastes and the documented evidence of releases
indicates that current management of phosphogypsum and phosphoric acid process wastewater may threaten
human health through drinking water exposures, threaten aquatic life, and may render water resources
unsuitable for potential consumptive uses. Although EPA estimates that phosphogypsum stacks pose an MEI
lifetime air pathway cancer risk of as much as 9xlO"5 as a result of radon emissions from the stacks, (with
minor contributions from radioactive and nonradioactive constituents in windblown dust) the Agency
-------
Chapter 12: Phosphoric Acid Production 12-59
concluded in its analysis of NESHAPs for phosphogypsum stacks that this level of risk is "acceptable."142
Consequently, EPA promulgated a work practice standard for radon flux from phosphogypsurn stacks that the
Agency "belives existing stacks meet... without the need for additional control technology.1
143
Likelihood That Existing Risks/Impacts Will Continue in the
Absence of Subtitle C Regulation
At many active phosphoric acid production plants, current waste management practices and
environmental conditions may allow contaminant releases and risks in the future in the absence of Subtitle C
regulation. For example, the stacks and ponds are typically unlined and in the Southeast, where the
phosphoric acid industry is most heavily concentrated, and ground water occurs in relatively shallow aquifers.
While these surficial aquifers are not typically used for drinking water purposes, they frequently are
hydraulically connected to aquifers or surface waters that supply drinking water. Similarly, catastrophic stack
and dike failures and long-term seepage from stacks and ponds have released process wastewater and
phosphogypsum constituents directly from management units to surface waters. Therefore, environmental
releases can occur and, considering the intrinsic hazard of the wastes, significant exposures could occur if
contaminated ground water is used as a source of drinking water.
The phosphoric acid production industry recently has been recovering from low production levels in
the mid-1980's and may continue to expand somewhat in the future if fertilizer use continues to grow in
response to increases in crop prices and planted acreage. Increases in production would likely be provided
by increased capacity utilization at active plants (e.g., in 1988 three plants operated at utilization rates of 16
to 38 percent) and the reactivation of plants that are presently on standby. Therefore, if phosphoric acid
production does increase, use of existing waste management units (both those at facilities evaluated in this
analysis and those at idle facilities that were not included in this analysis) would expand, potentially increasing
release potential and posing greater threats to human health and the environment. However, given the large
quantities of these wastes, and the ban of off-site use of phosphogypsum,144 it is unlikely that these wastes
will be used or disposed in significant quantities at off-site locations in the future.
State regulation of phosphoric acid production wastes varies considerably among the seven states in
which active plants are located, but requirements in most states may not be sufficient to control releases from
existing units and prevent threats to human health and the environment. For example, relatively
comprehensive solid waste regulations in Louisiana and Florida (under development) require liners and specify
closure requirements for new and expansions of existing stacks, but the state programs provide controls for
releases from existing units only through requirements for ground-water monitoring and performance standards
that in some cases allow off-site contamination. In North Carolina, phosphogypsum and process wastewater
are not defined as solid wastes, and are not subject to any solid waste regulations, though discharges from
waste management units must be permitted under the state's EPA-approved NPDES program. In summary,
state regulatory controls may not be sufficient to prevent releases of phosphogypsum and process wastewater
constituents from existing units, and in only a few states are regulations that specify construction and operation
standards in place or under development.
Costs and Impacts of Subtitle C Regulation
EPA has evaluated the costs and associated impacts of regulating both phosphogypsum and process
wastewater from phosphoric acid production as hazardous wastes under RCRA Subtitle C EPAs waste
characterization data indicate that phosphogypsum exhibited the hazardous waste characteristic of EP toxicity
at only one of the eight active facilities for which sampling data were available. EPAs data also indicate that
142 54 FR 51675. December 15,1989.
143 Ibid.
144 Ibid.
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12-60 Chapter 12: Phosphoric Acid Production
process wastewater is either corrosive or EP toxic or both at each facility for which sampling data were
available. Because of the relatively high potential for contamination as a result of the environmental settings
of most phosphoric acid sites (e.g., shallow ground water) and the large number of damage cases associated
with phosphoric acid production wastes, EPA employed the conservative assumption that phosphogypsum
would be EP toxic at untested facilities, and that process wastewater would be both corrosive and EP toxic at
untested facilities; the Agency's cost and impact estimates reflect this assumption and therefore probably
overestimate the impacts of prospective regulation.
For phosphogypsum, costs of regulatory compliance under the full Subtitle C scenario exceed S10
million annually at all affected facilities and range as high as $185 million per year; these costs would impose
potentially significant economic impacts on the operators of all affected plants. Application of the more
flexible Subtitle C-Minus regulatory scenario would result in compliance costs that, on average, are
approximately 60 percent lower, ranging from about $1 million to more than $65 million annually. Costs
under the Subtitle D-Plus scenario are approximately 19 percent lower than under Subtitle C-Minus, because
of further relaxation of waste management unit design and operating standards.
Subtitle C compliance costs would comprise a significant fraction of the value of shipments of and
value added by phosphoric acid production operations at most affected facilities; ratios at seven of the eleven
affected facilities exceed ten percent (five have ratios at or above 20 percent), while the remaining four exceed
four percent. Compliance cost ratios under the Subtitle C-Minus and Subtitle D-Plus scenarios generally range
from three to eight percent, though ratios at Agrico's Uncle Sam (LA) plant exceed eleven percent even under
the least stringent scenario. EPAs economic impact analysis suggests that the domestic phosphoric acid
industry is currently stronger than it has been in recent years, but would probably not be able to pass through
compliance costs in the form of significantly higher prices to product consumers. Moreover, because not all
domestic producers would be affected or affected equally, it is improbable that facilities experiencing high
compliance costs would be able to obtain higher product prices in any case, given the relatively low rate of
industry capacity utilization (77 percent overall in 1988). Therefore, if phosphogypsum were removed from
the Mining W-iste Exclusion, facilities at which this material was EP toxic might face new waste management
costs (even under modified Subtitle C standards) that could threaten their long-term profitability and hence,
their economic viability.
It is worthy of note that some impacts would be likely to occur even in the absence of a decision to
remove phosphogypsum from the Mining Waste Exclusion, because adequately protective waste management
standards under a Subtitle D program would require the construction of new waste management units at most
facilities, implying significant new capital expenditures.
Based upon existing waste characterization data, EPA believes that all of the 21 facilities generating
wet process phosphoric acid process wastewater might incur costs under a change in the regulatory status of
this waste. Annualized regulatory compliance costs under Subtitle C would exceed $225 million, ranging from
$4.7 to $26.3 million. Annualized new capital expenditures would account for approximately 45 percent of
the total, with the cost of wastewater tank treatment dominating overall costs. Under the Subtitle C-Minus
and D-Plus scenarios, the annualized compliance costs drop only slightly ($10-12 million in aggregate), due
to relaxed technical standards for operation of the surge ponds used to hold the wastewater prior to treatment.
The Agency expects that regulation of process wastewater as a hazardous waste under both Subtitle C and C-
Minus regulation could potentially pose a threat to the economic viability of affected domestic phosphoric acid
producers, based on estimated compliance cost impacts; estimated impacts under the Subtitle D-Plus scenario
are marginally lower. The significance of these impacts might be diminished by the possibility of the operators
reducing waste generation or physically separating waste streams generated from different operations, in order
to reduce the actual volume of water that would be hazardous and hence require treatment
Finally, EPA believes that incentives for recycling or utilization of phosphoric acid production wastes
would be mixed if a change in the regulatory status of this waste were to occur. The predominant management
alternative to disposal of phosphogypsum has been off-site use in construction applications and in agriculture.
Because of the recently promulgate NESHAP banning such use, however, EPA expects that phosphogypsum
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Chapter 12: Phosphoric Acid Production 12-61
will now be disposed on-site, regardless of the RCRA requirements that may be applied to such disposal, i.e.,
regulation under Subtitle C would affect only the costs of phosphogypsum management, not the type(s) of
management techniques employed. Direct recycling of phosphogypsum for additional product recovery is not
a viable option, and process changes that might affect the chemical properties of the material as well as
purification methods have been employed with variable success. It is likely that in response to new regulatory
requirements, facility operators would develop and implement measures to render their phosphogypsum non-
EP toxic. Process wastewater is currently internally recycled at all active facilities. The potential for reducing
the amount of water used and/or significantly reducing the total quantities of corrosive or otherwise hazardous
substances currently found in process wastewater is extremely limited, given the nature of wet process
phosphoric acid production operations.
-------
Chapter 13
Titanium Tetrachloride Production
For purposes of this report, the titanium tetrachloride (TiCl4) production sector consists of nine
facilities that, as of September 1989, were active and reported generating a special mineral processing waste:
chloride process waste solids. At one of these facilities (Timet at Henderson, NV) the TiCl4 produced is used
as feed material to manufacture titanium sponge metal. Two other titanium sponge producers, RMI and
Ormet, reported no generation of the special waste and purchase rather than produce their mineral-related
feedstock (TiC^).1 Therefore, they are not addressed in this report.
At the remaining eight TiCl4 facilities, the TiCl4 produced is used as feed material to produce
titanium dioxide (TiO2) pigment by a process known as the "chloride process." Chloride process waste solids
are generated during chlorination at all eight facilities. Adjacent to two chloride process facilities are two
sulfate process TiO2 pigment plants. The sulfate process wastes are not special mineral process wastes,
therefore, these sulfate process plants and their wastes are not addressed further in this report. The data
included in this chapter are discussed in additional detail in a technical background document in the
supporting public docket for this report
13.1 Industry Overview
Titanium tetrachloride is used as a feedstock to two major processes, production of titanium dioxide
and titanium sponge. Titanium dioxide is used primarily as a pigment in the paper and paint industries;2
titanium sponge, produced in much smaller volumes than TiO2, is used primarily in aircraft engines and
airframes.3 In the chloride process, high titanium concentrates are reacted with chlorine gas at high
temperature. The resulting titanium tetrachloride gas is condensed, purified by distillation, and then either
oxidized to titanium dioxide or reduced to titanium sponge. The nine active facilities are located across the
U.S., as shown in Exhibit 13-1.
Exhibit 13-1
Domestic Titanium Tetrachloride Producers
Owner
Ef. duPorrt
E.I. duPont
E.t. dtiPorrt
El. duPont
Kemlra
Kerr-McQee
SOW
SCM
T1MET
Location
Artkxh,CA
Edgemoor, DE
New Johmorwille. TN
Paaa Christian, MS
Savannah, QA
Hamilton, MS
AahtabukOH
Baltimore, MD
Henderson, NV
Ore Type
RutHe
llmenite
llmenite
llmenite
Rutte
Synthetic Rutile
Rutite, S. African Slag
Rutile, S. African Slag
Ruffle
1 According to BOM sources, RMI is planning to build its own TiCl4 facility, to be completed by year-end, 1991.
2 The paper industry primarily uses TiO2 produced by the sulfate process, which is not addressed in this report.
3 Lynd, Langtry, 1990. Personal communication, June 27,1990.
-------
13-2 Chapter 13: Titanium Tetrachloride Production
Titanium metal and titanium dioxide production have steadily increased throughout the late 1980's.
Between 1985 and 1989, titanium metal production increased by 12 percent from 21,000 metric tons to 24,000
metric tons. Production in 1989 was about 85 percent of capacity for the year. Demand for titanium mill
products also increased, mainly becau ; of the continued boom in orders for new commercial airliners and
expansions in the pulp and paper and chemical industries. While imports for consumption dropped in 1989,
exports of titanium metal increased. In 1989, two companies completed expansion of their capacity, bringing
total U.S. capacity to approximately 28,000 metric tons. One company announced plans for further expansion
from 5,400 metric tons per year to 8,000 metric tons per year by March 1991.4
U.S. production of titanium dioxide pigments increased approximately 8 percent in 1989 from 926,746
metric tons, to 1,007,000 metric tons, setting a new record-high level for the seventh consecutive year.
Consumption eased slightly but was close to the record level reached in 1988. Domestic producers increased
total capacity by approximately 125,000 metric tons, via process optimization as well as major expansions.
Additional new capacity planned to be on-line in 1990-91 totals about 240,000 metric tons, which would
increase total U.S. capacity to approximately 1300,000 metric tons.5
Demand for titanium and titanium dioxide are closely tied to the overall economy. Future demands
depend upon the health of the economy in the 1990s. In 1989, about 80 percent of the titanium metal
consumed was used in jet engines, airframes, and space and missile applications, while about 20 percent was
used in the chemical-processing industry, power generation, marine and ordnance, medical, and other non-
aerospace applications. Also, in 1989 approximately 48 percent of the titanium dioxide consumed was used
in paint, varnishes, and lacquers; the remaining use of titanium dioxide was divided between paper (24
percent), plastics (17 percent), rubber (2 percent), and others (9 percent).6 Industry sources indicate that
world demand for titanium will grow at approximately 3 percent per year for pigment and 5 percent for metal
for the next several years.7
Four of the titanium dioxide facilities are owned by one company, E.I. duPont de Nemours, two by
SCM (which also operates a sulfate process plant), and one each by Kerr-McGee and Kemira (which also
operates a sulfate process plant). Timet produces titanium sponge using the chloride process. All of the
capacity and production data that were submitted by facility operators in response to the 1989 SWMPF Survey
have been designated confidential by the individual respondents. Therefore, EPA has relied upon information
from published sources to develop the necessary estimates for the analyses that follow.
Tbtal titanium tetrachloride capacity is estimated to be 1.8 million metric tons per year.
Approximately 41,000 metric tons of this capacity is the Henderson facility that primarily uses the product as
a feedstock for titanium sponge production. The remaining capacity is at facilities whose primary use of the
product is in production of titanium dioxide; a small portion of titanium tetrachloride produced at these
facilities is sold for other uses. The Bureau of Mines estimates the long-term capacity utilization for these
facilities to be 100 percent of capacity; 1988 capacity utilization at the Henderson facility was reportedly 87
percent of capacity or about 36300 metric tons of titanium tetrachloride. The Bureau of Mines has reported
that increased capacity of approximately 600,000 metric tons of titanium tetrachloride for use primarily in the
production of titanium dioxide is expected by 1992.
Production of titanium tetrachloride involves chlorination of a titanium concentrate. The type of
concentrate, however, may vary greatly between different companies and facilities, as shown in Exhibit 13-1.
duPont's Antioch facility and the Kemira and SCM facilities use rutile, a high-grade concentrate containing
* Langtry E. Lynd, U.S. Bureau of Mines, Mineral Commodity Summaries. 1990 Ed., p. 180.
5 Ibid.
* Ibid.
7 "Titanium: The Market is - in the Air," E&MJ. March 1990, p. 41.
-------
Chapter 13: Titanium Tetrachloride Production 13-3
approximately 95 percent titanium dioxide.8 The SCM facilities may also use, in addition to nitile, a South
African slag as a feedstock9 that contains approximately 85 percent TiO2.10 In addition to rutile, iimenite,
a lower grade mineral with TiO2 content ranging from 45-65 percent, which is typically routed to the sulfate
process, may also be used in the chloride process. Kerr-McGee's Mobile facility beneficiates Australian
iimenite to produce a synthetic rutile that is shipped to its Hamilton facility for chlorination. The three
remaining duPont facilities use a high-grade ilraenite in a one-step "ilmenite-chlorination process."11
Irrespective of the feedstock type or source, in a typical titanium tetrachloride operation, as shown
in Exhibit 13-2, the ore is chlorinated in a fluidized-bed reactor in the presence of coke. The volatile metal
chlorides are collected and the special waste, the non-volatile chlorides and the unreacted solids that remain,
are discharged. The gaseous product stream is purified to separate the titanium tetrachloride from other
chlorides. Acidic liquid waste streams, primarily ferric chlorides, are the primary liquid waste stream from this
purification process; these are, however, not special wastes. Vanadium oxychloride, another low volume non-
special waste, is not removed from titanium tetrachloride by distillation; rather it is separated by complexing
this material with mineral oil followed by reduction with hydrogen sulfide, or by complexation with copper.
The purified titanium tetrachloride is then oxidized to titanium dioxide or reduced to titanium sponge and the
chlorine gas liberated by this process is typically recycled.12 The non-volatile chlorides and the unreacted
process solids that remain after the reaction in the fluidized-bed reactor are the special waste under study in
this report. These solids, suspended in chloride process waste acids, are treated and discharged. As noted in
the January 23, 1990 final rule (54 FR 2322), the slurried residue from the "chloride-ilmenite" process
reportedly employed by three titanium tetrachloride production facilities are considered to be chloride process
waste solids.
13.2 Waste Characteristics, Generation, and Current Management Practices
The special mineral processing waste generated by titanium tetrachloride processing is chloride
process waste solids. The solids are typically generated in a slurry with waste acids; the solids in the slurry
are particles with a diameter less than 0.02 mm (smaller than sand). The solids in this slurry are the special
waste; the waste acid is not a special waste and is not discussed in this report.
Eight of the nine companies generating this waste requested that waste generation rate data be
regarded as confidential business information; therefore, no facility-specific waste generation data are presented
in this report. The aggregate annual industry-wide generation of chloride process waste solids by the nine
facilities was approximately 414,000 metric tons in 1988, yielding a facility average of nearly 46,000 metric tons
per year. Ratios of metric tons of chloride solids to metric tons of titanium tetrachloride produced range from
0.07 to 0.80 and average 0.208 for the sector.
Using available data on the composition of chloride process waste solids, EPA evaluated whether the
waste solids exhibit any of the four characteristics of hazardous waste: corrosivity, reactivity, ignitability, and
extraction procedure (EP) toxicity. Based on available information and professional judgment, the Agency
does not believe the waste solids are corrosive, reactive, or ignitable, but some solids exhibit the characteristic
8 Lynd, 1988. Personal communication, Langtry Lynd, Titanium Commodity Specialist, U.S. Bureau of Mines, Washington D.C.,
August, 1988.
9 Ibid.
10 Bureau of Mines, 1985. Mineral Facts and Problems. 1985 Ed., p. 865.
11 E.I. duPont de Nemours, 1989. Public comments from duPont addressing the 1989 proposed Reinterpretation of Mining Waste
Exclusion pocket No. - MWRP00023); May 31,1989, pp. 7-8.
12 Environmental Protection Agency, 1984. Overview of Solid Waste Generation. Management, and Chemical Characteristics: Primary
Antimony, Magnesium, Tin, and Titanium Smelting and Refining Industries. Prepared by PEI Associates for the U.S. EPA, December
1984.
-------
13-4 Chapter 1 & Titanium Tetrachloride Production
Exhibit 13-2
Titanium Tetrachloride Production*
Rutile. llmenite.
or Synthetic Rutile
e F
Chlorination/
Purification
^
TICI4
^
Waste Acids *^
r and Solids
Oxidation
Reduction
PROCESS
SPECIAL WASTE
MANAGEMENT
Legend
Production Operation
Ti02
Titanium
Sponge
Neutralization
(Some Facilities)
and Solids/Liquids
Separation
Special Waste
o
Waste Management Unit
And Related Activities (i.e., Ti02 and Titanium Sponge Production)
of EP toxicity. EP leach test concentrations of all eight inorganic constituents with EP toxicity regulatory
levels are available for waste solids from six of the nine facilities of interest (data on mercury concentrations
were available from only three facilities). Of these constituents, only chromium and lead concentrations were
found to exceed the EP toxicity levels. Of the 16 samples analyzed, concentrations of chromium exceeded the
regulatory levels in only 3 samples, 1 each from the Edgemoor, New Johnsonville, and Henderson facilities.
Chromium was present at concentrations in excess of the regulatory level by a factor ranging from 1.1 to 20.
Lead concentrations exceeded the regulatory level in just 1 sample (from the Henderson facility) by a factor
of 6.3. At one facility for which comparable SPLP test data are available, lead and chromium concentrations
as determined by SPLP analyses also exceeded the EP toxicity regulatory levels by roughly the same margins
as h., EP test results.
The waste management practice used at titanium tetrachloride production facilities to manage chloride
process waste solids is treatment of the stream as generated (i.e., in a slurry) and disposal of the solid residual
(i.e., the special waste).
-------
Chapter 13: Titanium Tetrachloride Production 13-5
13.3 Potential and Documented Danger to Human Health and the Environment
This section addresses two of the study factors required by §8002(p) of RCRA: (1) potential danger
(i.e., risk) to human health and the environment; and (2) documented cases in which danger to human health
or the environment has been proved. Overall conclusions about the hazards associated with the waste solids
are provided after these two study factors are discussed.
13.3.1 Risks Associated With Chloride Process Waste Solids
Any potential danger to human health and the environment from chloride process waste solids
depends on the composition of the waste, the management practices that are used, and the environmental
settings of the facilities where the waste solids are generated and managed.
Constituents of Concern
EPA identified chemical constituents in chloride process waste solids (as managed) that may present
a hazard by collecting data on the composition of the solids and evaluating the intrinsic hazard of the chemical
constituents.
Data on Chloride Process Waste Solids Composition
EPAs characterization of chloride process waste solids and leachate is based on data from two
sources: (1) a 1989 sampling and analysis effort by EPAs Office of Solid Waste (OSW); and (2) industry
responses to a RCRA §3007 request in 1989. These data provide information on the concentrations of 21
metals, chloride, fluoride, sulfate, and 3 radionuclides (radium-226, thorium-232, and uranium-238) in total
and/or leach test analyses, and represent samples from 6 facilities.
Concentrations in samples of the chloride process waste solids are consistent for most constituents
across all data sources and facilities. Arsenic concentrations in the solids, however, vary over five orders of
magnitude across the facilities. Chemical concentrations in the waste solids leachate are generally consistent
across the data sources, types of leach tests (i.e., EP and SPLP), and facilities.
Process for Identifying Constituents of Concern
As discussed in detail in Section 2.2.2, the Agency evaluated the data summarized above to determine
if chloride process waste solids or leachate from the solids contain any chemical constituents that are
intrinsically hazardous, and to narrow the focus of the risk assessment. The Agency performed this evaluation
by first comparing the concentrations of chemical constituents to screening criteria that reflect the potential
for hazards, and then by evaluating the environmental persistence and mobility of any constituents present in
concentrations above the criteria. These screening criteria were developed using assumed scenarios that are
likely to overestimate the extent to which the waste solid constituents are released and migrate through the
environment to possible exposure points. As a result, this process identifies and eliminates from further
consideration only those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic organisms, and water quality (see Exhibit 2-3). Given the conservative (i.e., protective) nature
of these screening criteria, contaminant concentrations in excess of the criteria should not, in isolation, be
interpreted as proof of hazard. Instead, exceedances of the criteria indicate the need to evaluate the potential
hazards of the waste solids in greater detail.
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13-6 Chapter 13: Titanium Tetrachloride Production
Identified Constituents of Concern
Exhibits 13-3 and 13-4 summarize the frequency with which the chemical and radioactive constituents
of the chloride process waste solids and leachate exceed the risk screening criteria. Data are provided in the
exhibits for all constituents that are present in concentrations that exceed a screening criterion.
Exhibit 13-3 identifies constituents in the waste solids that, based on total sample analysis results,
were detected in concentrations above the screening criteria. Only 5 of the 28 constituents analyzed in the
waste solids exceed the screening criteria: arsenic, chromium, radium-226, thorium-232, and uranium-238.
Of these constituents, chromium and radium-226 exceed the screening criteria most frequently, in at least 83
percent of all samples analyzed and at all facilities for which data are available. Chromium concentrations
exceed the screening criteria by the widest margin, by as much as a factor of 75. Radium-226 levels as high
as 24.5 pCi/g (5 times the screening criterion) were measured. In addition, maximum concentrations of 43
pCi/g of uranium-238 and 89 pCi/g thorium-232 exceed the screening criteria by factors of 4.3 and 8.9,
respectively.13 The other constituents exceed the screening criteria by a factor of 15 or less. These
exceedances indicate the potential for several types of impacts, as follows:
• Chromium, arsenic, thoriurn-232, and uranium-238 concentrations in the waste solids
may pose a cancer risk of greater than IxlO"5 if dust from the solids is blown into the
air and inhaled in a concentration that equals the National Ambient Air Quality
Standard for paniculate matter. As discussed in more detail in the next section, there
is a moderate potential for dust to be blown into the air at the four facilities that
manage the waste solids in waste piles and landfills.
Exhibit 13-3
Potential Constituents of Concern in
Titanium Chloride Process Waste Solids(a)
Potential
Constituent*
of Concern
Chromium
Thorium-232
Uranium-238
Radium-226
Arsenic
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
14/14
12/12
12/12
12/12
3/8
Human Health
Screening Criteria11*
inhalation*
Inhalation*
Radiation*(c)
inhalation*
Radiation***
Radiation*®
ingestion*"
Inhalation*
No. of Analyse*
Exceeding Criteria/
No. of Analyses for
Constituent
14/14
1 M2
1 /12
1/12
2/12
10/12
2/8
2/8
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
6/6
1 /1
1 /1 •
1 /1
1/1
1 /1
T/6
1/6
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The screening criteria values used in this analysis are listed in Exhibit 2-3. Constituents
that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10'5 lifetime cancer
risk; others are based on noncancer effects.
(c) Includes direct radiation from contaminated land and inhalation of radon decay products.
° These radionuclide concentrations are similar to those reponed in other sources. Specifically, "old sludge" from a titanium-
chlorination process is reponed to have 57 pCi/g uranium-238,77 pCi/g thorium-232, and 25 pCi/gm radium-226 in Repon No. 2 Natural
Radioactivity Contamination Problems, Conference of Radiation Control Program Directors, Inc., August, 1981.
-------
Chapter 13: Titanium Tetrachloride Production 13-7
Exhibit 13-4
Potential Constituents of Concern in
Titanium Chloride Waste Solids Leachate(a)
Potential
Constituents
of Concern
Iron
Radium-226
Manganese^
Chromium
Lead
Aluminum
Molybdenum
Copper
Vanadium
Arsenic'0'
Silver'e)
Nickel
Thallium®
Antimony
Selenium**
Cobalt'0'
No. of Times
Constituent
Detected/No, of
Analyses
for Constituent
3/3
2/2
4/4
8/16
S/16
3/3
2/3
2/3
3/4
1/5
1 /4
3/4
1/4
1 /3
1/5
1/4
Screening Criteria0"
Resource Damage
Aquatic Damage
Human Hearth'
Human Health
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health*
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Human Health
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
No. of Analyses
Exceeding Criteria/
No. of Analyses for
Constituent
3/3
2/3
2/2
1/4
4/4
4/16
7/16
5/16
4/16
5/16
4/16
1/3
2/3
2/3
2/3
I/*
2/4
1/4
1/5
1/5
1/4
1/4
1/4
1/4
1 /4
1 /4
t/4
1/3
t/5
1/5
1/4
No. of Facilities
Exceeding Criteria/
No. of Facilities
Analyzed for
Constituent
3/3
2/3
1 /1
1/4
4/4
3/6
5/6
5/6
4/6
5/6
4/6
1 /3
2/3
2./3
2/3
1 /4
2/4
1/4
1 /4
1 /4
1/4
1 /4
1 /4
1 /4
1 /4
1 /4
1 /4
1 /3
1 /4
1/4
1 /4
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The screening criteria values used in this analysis are listed in Exhibit 2-3. Constituents
that were not detected in a given sample were assumed not to be present in the sample. Unless otherwise noted, the
constituent concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on cancer risk or noncancer health effects. "Human health* screening criteria
noted with an '*' are based on a 1x10'5 lifetime cancer risk; others are based on noncancer effects.
(c) Data for this constituent are from SPLP leach test results.
-------
13-8 Chapter 13: Titanium Tetrachloride Production
• Arsenic concentrations in the waste solids could pose a cancer risk of more than IxlO"5
if a small quantity of the solids is incidentally ingested on a routine basis (which could
occur if access to closed waste management units is not restricted or if the solids are
used off-site in an unrestricted manner that allows children to come into direct contact
with the waste).
• The concentrations of thorium-232, uranium-238, radium-226, (which were analyzed for
in samples from only one facility) and other members of the uranium and thorium decay
chains could pose a radiation hazard if the waste solids are allowed to be used in an
unrestricted manner. For example, direct radiation doses and doses from the inhalation
of radon decay products could be unacceptably high if the solids were to be used as fill
material around homes.
Of the 25 constituents analyzed in the waste solids leachate, 16 were present in concentrations that
exceed the screening criteria (see Exhibit 13-4). Among these constituents, chromium, copper, iron, lead,
radium-226, manganese, and molybdenum concentrations in the leachate exceed the screening criteria most
frequently and at the greatest number of facilities. Constituents present in concentrations that exceed the
screening criteria by a factor of 10 or more include: aluminum, arsenic, chromium, iron, lead, manganese,
molybdenum, nickel, vanadium, silver, and thallium. Measured concentrations of arsenic, chromium, iron, lead,
manganese, vanadium, and silver also occasionally exceed the screening criteria by a factor of 100 or more.
Lead concentrations in the leachate exceed the screening criteria by the widest margin (up to a factor of 625),
and as discussed in section 13.2, lead and chromium were measured in concentrations that exceed the EP
toxicity regulatory levels. These exceedances indicate the potential for the following types of impacts under
the following conditions:
• Concentrations of arsenic, antimony, chromium, lead, manganese, nickel, radium-226,
vanadium, silver, and thallium in the leachate exceed the human health screening
criteria. This means that if the leachate migrates to drinking water sources with less
than ten-fold dilution, long-term ingestion of untreated drinking water may cause
adverse health effects. The diluted arsenic and radium-226 concentrations may cause
a cancer risk of more than IxlO"5.
• If the leachate migrates to surface or ground water with less than ten-fold dilution, the
resulting concentrations of several constituents could render the water unsuitable for
certain uses without prior treatment (i.e., cause water resource damages). Specifically,
the diluted concentrations of arsenic, chromium, iron, lead, manganese, selenium, and
silver may exceed the drinking water maximum contaminant levels, rendering the water
unfit for human consumption. The diluted concentrations of aluminum, cobalt,
molybdenum, nickel, and vanadium may exceed irrigation guidelines, rendering the water
less desirable for use for agricultural purposes.
• Concentrations of aluminum, chromium, copper, iron, lead, nickel, selenium, silver, and
vanadium in the leachate may present a threat to aquatic organisms if the leachate
migrates (with less than 100-fold dilution) to surface waters.
These exceedances do not prove that the waste solids pose risk to human health and the environment,
but rather indicate that the solids may present a hazard under very conservative, hypothetical exposure
conditions. To examine the hazards associated with this waste in greater detail, the Agency proceeded to the
next step of the risk analysis to evaluate the actual release, transport, and exposure conditions at the plants
that actively generate and manage the waste solids.
Release, Transport, and Exposure Potential
The following analysis considers the baseline hazards of the waste as it was generated and managed
at the nine titanium tetrachloride producing facilities in 1988. This evaluation does not assess the hazards of
off-site use or disposal of the waste solids because the solids are never utilized managed off-site (nor are they
likely to be in the near future). In addition, the analysis does not consider the risks associated with potential
-------
Chapter 13: Titanium Tetrachloride Production 13-9
future changes in waste management practices or population patterns, because of a lack of adequate
information on possible future conditions.
Ground-Water Release, Transport, and Exposure Potential
EPA and industry test data show that several constituents are capable of leaching from the chloride
process waste solids in concentrations above the screening criteria. Given the low-pH conditions that are
expected to exist, a large number of these constituents will be relatively mobile in ground water, including
antimony, arsenic, chromium, copper, cobalt, iron, lead, manganese, nickel, selenium, silver, and thallium. Of
these constituents, arsenic, chromium, iron, lead, manganese, and silver pose the greatest potential ground-
water threat, considering their concentrations in the leachate relative to the screening criteria. Key factors
that influence the potential for these constituents to cause ground-water impacts at each facility are
summarized in Exhibit 13-5.
The waste solids are managed in surface impoundments and/or settling ponds at the eight facilities
that did not declare their management techniques as confidential. These eight facilities are located in Antioch,
CA, Edgemoor, DE, Hamilton, MS, Ashtabula, OH, New Johnsonville, TN, Pass Christian, MS, Henderson,
NV, and Savannah, GA At these sites, the waste solids are discharged as a slurry to the impoundments, where
they settle to the bottom as a sludge. The standing liquid that is held on top of the settled solids provides a
force that may drive contaminants from the solids to the subsurface. In this situation, the potential for release
depends on the design features of the impoundments, the depth to ground water, and the permeability of the
earth materials beneath the impoundments; the potential for exposure to contamination (if it occurs) depends
on the surrounding ground-water use patterns. Considering these factors, which are summarized on a site-
specific basis in Exhibit 13-5, the eight sites with impoundments can be grouped into three categories:
• There is a relatively high potential for ground-water contamination and subsequent
exposure at the Hamilton facility. There are no known controls (e.g., liner or leachate
collection systems) on the impoundments, the ground water is moderately shallow
(roughly 6 meters deep), the substrate beneath the impoundments is a permeable sand,
and there appears to be a drinking water well within 700 meters downgradient. This
well, however, is on the opposite side of McKinley Creek from the impoundments, and
thus may not receive full contaminant loadings from the impoundments (due to ground-
water discharge to the creek).
• The potential for ground-water release and exposure is moderate at the Ashtabula and
Savannah facilities. At Ashtabula, the on-site impoundment is underlain by in-situ clay
and recompacted local clay, the ground water is moderately shallow (6 meters deep), the
subsurface is mainly impermeable silt and clay, and the nearest downgradient drinking
water well is roughly 800 meters away. Although the impoundment at Savannah is
equipped with a leachate collection system, the ground water is shallow (3 meters deep),
the subsurface is mainly a permeable sand, and there appears to be a drinking water well
within 200 meters downgradient.
• The potential for release to ground water is relatively high at the Antioch facility, but
the potential for exposure to any ground-water contamination appears low. There are
no known controls on the on-site impoundments, the ground water is very shallow (1
meter deep), and the subsurface is a permeable sand. However, the aquifer does not
contain freshwater and does not appear to be used in the area.
• The potential for ground-water release and exposure at the facilities in Edgemoor, New
Johnsonville, Pass Christian, and Henderson appears relatively low. At these facilities,
the impoundments are equipped with either in-situ clay, recompacted clay, or, as is the
case at Henderson, synthetic liners. The depth to useable ground water ranges from 6
to 48 meters, the underlying earth materials are generally sandy, and there are no known
uses of the ground water within 1.6 km (1 mile).
-------
13-10 Chapter 13: Titanium Tetrachlorlde Production
Exhibit 13-5
Summary of Release, Transport, and Exposure Potential
for Chloride Process Waste Solids
Facility
Release, Transport, and Exposure Potential
Proximity 10
Sensitive Environments
ANTIOCH
Ground water: No information on the engineered controls for small
on-srte settling pond, but because of the relatively permeable
subsurface (90% sand), releases to the very shallow aquifer (0.6 to
1.2 meters) are possible. Exposures unlikely because the aquifer
does not contain fresh water and is not used in the area.
Surface water: Moderate annual precipitation (41 cm/year) and
gently sloped land (0-2%) limit potential for storm water to cause
overflowing from the settling pond. Migration of contaminants to
San Joaquin River (located 920 meters away) via recharge to
ground water could occur; potential for ecological impacts and
resource damage is low due to the large assimilative capacity
(5,000 mgd) of the river; moderate potential for current human
health risks because there is an intake for drinking water located
within 100 meters downstream of the facility.
Air: Releases unlikely because waste solids remain submerged
beneath liquid.
Located within 1.6 km of
a wetland and within 2.6
km of an endangered
species habitat
EDGEMOOR
Ground water: Releases limited by recompacted local clay liners.
Even if releases to shallow ground water (6 meters) occur, there are
no users of the ground water within 1.6 km downgradient
Surface water: Routine overland releases limited by stormwater
run-on/run-off controls; because of high precipitation (104 cm/year),
the steep topographic slope (6 to 12%), and possible floods (facility
located in 100-year floodplain), episodic overflow and overland
runoff could occur. The Delaware River is located very close (10
meters) from the boundary of the facility, but is not used as a
source of drinking water within 24 km downstream.
Air: Releases unlikely because wastes solids remain submerged
beneath liquid.
Located in a 100-year
floodplain
NEW JOHNSONVIU-E
Ground water: Five surface impoundments are underlain by
recompacted local clay while the single landfill is not lined.
Although there is relatively high precipitation (126 cm/yr) and
recharge (28 cm/yr), significant releases to ground water unlikely
because water table is moderately deep (11 m) and useable ground
water is even deeper (49 m). No known users of the aquifer within
1.6 km.
Surface water: Although there is high precipitation in the area,
potential for erosion from the landfill and overflow from the surface
impoundments is limited by moderate topographic slope (2-6%)
and stormwater run-on/run-off controls; releases via recharge to
ground water could occur to the Tennessee River located 30 meters
away, but its very large flow (42,000 mgd) yields significant dilution
capacity; there is a downstream drinking water intake supplying
approximately 400 people.
Air: Releases from landfill not controlled by dust suppression;
small number of wet days (98 days/year) and average wind speeds
up to 3.4 m/s could lead to airborne dust There are no residences
within 1.6 km of the facility.
Located within 1 mile of a
National Park
-------
Chapter 13: Titanium Tetrachloride Production 13-11
Exhibit 13-5 (cont'd)
Summary of Release, Transport, and Exposure Potential
for Chloride Process Waste Solids
Facility
Release, Transport, and Exposure Potential
Proximity to
Sensitive Environments
PASS CHRISTIAN
Ground water: Although two surface impoundments, one settling
pond, and one landfill are underlain by recompacted clay, releases
may occur due to the high precipitation (160 cm/year), moderate
net recharge (15 cm/year), and shallow water table (2 meters);
however, the useable aquifer is deep (26 m) and there are no
drinking water wells within 1.6 km downgradient of the facility.
Surface water: Although facility is located in high precipitation
area, overland runoff limited by stormwater run-on/run-off controls
and gentle topographic slope (0-2%). Contaminants could migrate
to the St. Louis Bay (274 meters away) via recharge to shallow
ground water (2 meters deep).
Air: Releases from landfill not controlled by dust suppression;
small number of wet days (92 days/year) and average wind speeds
up to 4.2 m/s could lead to airborne dust and inhalation exposures
at closest residence 60 meters from the facility, as well as potential
food chain exposures through deposition of particulates on agricul-
tural fields within 1.6 km; a total of 30 people live within 1.6 km.
Located in a 100-year
floodplain and wrthin 1.6
km of a wetland
SAVANNAH
Ground water: Surface impoundment is equipped with leachate
collection system, but is without a liner; waste pile is without any
ground-water controls; potential for releases to ground water
because of high precipitation (126 cm/year), moderate net recharge
(15.3 cm/year), permeable subsurface (85% sand), end shallow
useable aquifer (3 meters). Potential drinking water exposure could
occur at municipal well 183 meters downgradient
Surface water: Overland run-off limited by stormwater run-on/run-
off controls at both management units, and gentle topographic
slope (0-2%). Contaminants could migrate to nearby Savannah
River (90 meters) via ground-water recharge; no consumptive uses
of the river within 24 km, and releases to surface water pose low
aquatic ecological risks (because of the river's large dilution
capacity, i.e., 8,000 mgd).
Air: Air releases not controlled by dust suppression; moderate
number of wet days (111 days/year), average wind speeds up to
3.4 m/s, and low height of waste pile (12 meters) may limit airborne
dust to an extent; potential inhalation exposures could occur at
closest residence within 100 meters of the facility.
Located within 1.6 km of
a wetland and the Savan-
nah National Wildlife
Refuge
HAMILTON
Ground water: Releases from two large impoundments to the
shallow usable aquifer (6 meters) could occur because of the fairly
permeable subsurface (93% sand) and moderate net recharge (13
cm/year); impoundments border McKinley Creek and ground water
may discharge directly into the creek without being used; however,
if ground water passes beneath the creek, a well 700 meters
downgradient may become contaminated.
Surface water: Overland release from the impoundments is limited
by stormwater run-on/run-off controls, and gentle topographic slope
(0-2%); releases to nearby McKinley Creek (60 meters) could occur
by recharge from ground water; low potential for human health or
ecological risks because of the large flow of the creek (5,000 mgd);
a drinking water intake exists 1,700 meters downstream.
Air: Releases unlikely because waste solids remain submerged
beneath liquid.
Located within 1.6 km of
a wetland
-------
13-12 Chapter 13: Trtanlum Tetrachlorlde Production
Exhibit 13-5 (cont'd)
Summary of Release, Transport, and Exposure Potential
for Chloride Process Waste Solids
Facility
Release, Transport, and Exposure Potential
Proximity to
Sensitive Environments
ASHTABULA
Ground water: Two surface impoundments are underlain by in-sftu
clay and recompacted local clay that could prevent releases to
ground water; if releases were to occur to the shallow aquifer (6
meters), potential drinking water exposures could occur at munici-
pal well 800 meters downgradient.
Surface water: Overland releases from the impoundments are
limited by stormwater run-on/run-off controls and gentle topo-
graphic slope (0-2%); releases to nearby Lake Erie (700 meters)
could occur by recharge to ground water; releases to the lake
should be diluted significantly.
Air: Releases unlikely because waste solids remain submerged
beneath liquid.
Located in a fault zone
BALTIMORE
Ground water: All specifications on the two management units are
confidential; moderately shallow ground water (9 m) brackish and
not used; uaeable aquifer at 137 m protected by clay confining
layer; no consumptive uses of the aquifer within 1.6 km of the
facility.
Surface water: No information on controls to prevent overland run-
off, but potential lor run-off could be significant because of high
precipitation and relatively impermeable subsurface; migration of
contaminants via recharge to shallow ground water that discharges
to the closest surface water, i.e., Chesapeake Bay (490 meters)
could occur.
Air: Moderate number of wet days (103 days/year) could limit
airborne releases to an extent; if the high wind speeds (average
wind speeds up to 5.3 m/s) lead to airborne dust, potential expo-
sures would be minimal because there are no residences within 1.6
km of the facility.
Located within 1.6 km of
a wetland
HENDERSON
Ground water: Surface impoundment has a synthetic liner but
waste pile has no ground-water controls; depth to useable aquifer is
not known but releases are limited by low precipitation (11 cm/
year), and zero net recharge; no drinking water wells within 1.6 km
downgradient
Surface water: Overland run-off limited by stormwater run-on/run-
off controls, gentle topographic slope (2-6%), and low annual
precipitation; nevertheless, the facility is located in a 100-year
floodplain and episodic release could occur in a flood event A
lake (Las Vegas Wash) is located just 46 meters from the facility
and potential human health exposures could occur at a drinking
water intake 1100 meters from the facility.
Air: Releases not controlled by duet suppression; very small
number of wet days (21 days/year), height of waste pile (6 meters),
and average wind speeds into 4.1 m/s could lead to airborne dust
and inhalation exposures at closest resident 90 meters from the
facility. Population within 1.6 km of the facility is 5,000.
Located in a 100-year
floodplain, and within 1.6
km of an wetland and the
Lake Mead National
Recreation Area
-------
Chapter 13: Titanium Tetrachlorlde Production 13-13
The four facilities located in New Johnsonville, TN, Pass Christian, MS, Henderson, NV, and
Savannah, GA periodically dredge solids from the impoundments described above and place the dried solids
in on-site landfills or waste piles. In general, the potential for contaminants to leach from these units into
ground water is significantly lower than the potential for release from the impoundments. In waste piles or
landfills, the hydraulic head that may force contaminants out of the impoundments has been removed and the
potential for release is limited by the amount of rainfall that is able to infiltrate through the pile or landfill
and into the ground. Considering the site-specific factors summarized in Exhibit 13-5:
• There is a moderate potential for release from the waste pile and landfill at the
Savannah and Pass Christian facilities. At both sites, the waste management unit is not
lined, net recharge is moderate (15 cm/yr), and ground water is shallow (2 to 3 meters
deep). There also appears to be a drinking water well within 200 meters downgradient
of the Savannah facility. The useable aquifer at Pass Christian is 26 meters deep, and
there appears to be no downgradient wells that withdraw water from this aquifer within
1.6 km (1 mile).
• The potential for significant releases from the piles/landfills at the New Johnsonville and
Henderson facilities is low. Although the net infiltration of water into the ground at
New Johnsonville is moderate (28 cnVyear), the ground water is relatively deep (llm
to the water table and 48 meters to a useable aquifer) and contaminants leaching from
the landfill at this site will likely be predominantly bound up in the soil in the
unsaturated zone. The Henderson facility is located in a very arid area with low
precipitation (around 11 cm/yr) and essentially no net recharge. Therefore, there is
virtually no water available to seep through the pile at this site and carry contaminants
to the subsurface.
The type and characteristics of the waste management unit(s) at the facility in Baltimore, MD are
confidential. However, based on the depth to useable ground water14 (137 meters), impermeable subsurface
(70% clay), and current aquifer-use patterns in the vicinity of this facility (virtually all water is provided by
the city water supply, the sources of which are several distant reservoirs;, the potential for release to potable
ground water and subsequent human exposure appears minimal.
Surface Water Release, Transport, and Exposure Potential
In theory, contaminants from chloride process waste solids could enter surface waters by two main
pathways: (1) migration of leachate through ground water that discharges to surface water; and (2) direct
overland (stormwater) run-off in either a dissolved form or in the form of solid particles. Based on the
available data on the waste solids composition, the solids contain a number of constituents in concentrations
that are above the screening criteria. Site-specific factors that influence the potential for these contaminants
to migrate to surface waters are summarized in Exhibit 13-5.
Direct overland run-off of the waste contaminants when managed in surface impoundments is limited
to a large extent by run-on/run-off controls at each site, and appears possible only in the event of a flood at
the Edgemoor, Pass Christian, and Henderson facilities (which are located in 100-year floodplains). It is more
likely that waste solids contaminants managed in surface impoundments might migrate to surface water by
leaching into ground water that discharges to surface water. Considering the ground-water release potential
(as discussed in the section above) and the proximity of the plants to surface waters, the potential for release
of waste solids contaminants from impoundments to surface water appears greatest at the Antioch, Hamilton,
Ashtabula, Edgemoor, and Savannah facilities. The distances between these facilities and the nearest surface
water bodies ranges from 10 to 880 meters. However, all of these water bodies are very large and have flows
capable of readily diluting small contaminant loads from ground water (e.g., the annual average flows of rivers
nearest the Antioch, Hamilton, and Savannah facilities are 5,000 mgd or greater, and the Ashtabula facility
14 There is a shallow aquifer less than 10 meters from the surface, but due to salt water intrusion, this aquifer is no longer suitable
for use as a water supply.
-------
13-14 Chapter 13: Titanium Tetrachlorlde Production
is adjacent to Lake Erie). Therefore, based on all of these factors, there is a minimal potential for the solids
to cause significant surface water impacts when managed in surface impoundments.
When managed in piles and landfills, the waste solids are more likely to migrate into surface waters
via stormwater erosion (as discussed in the preceding section, there is only a moderate potential for
contaminants to seep into ground water from these units, and this potential exists at only two facilities). The
physical form of the waste solids should not limit the erosion and subsequent entrainment of solids in run-off.
Particles that are 0.1 mm or less in size tend to be appreciably credible, and a large fraction of the waste solids
are expected to be in this size range (chloride process waste solids particles are typically on the order of 0.02
mm in diameter). Again, only the New Johnsonville, Pass Christian, Henderson, and Savannah facilities
manage the waste solids in piles or landfills. The potential for waste solids contaminants from these sites to
cause significant surface water impacts is limited by several factors, as summarized below:
• Although the New Johnsonville and Savannah facilities are located in areas with high
precipitation (126 cm/year), routine overland runoff from the on-site waste pile and
landfill is limited by stormwater nin-on/run-off controls and moderately gentle slopes
(less than 6 percent). Moreover, the potential for surface water damages is low because
the Tennessee and Savannah Rivers located within 100 meters of the facilities have large
capacities to assimilate contaminant inflows (i.e., average flows of 42,000 and 8,000 mgd,
respectively).
• Although the Pass Christian facility is only 30 meters from the St. Louis Bay, routine
releases to the bay from the on-site landfill via either ground-water discharge or
stormwater erosion are likely to be readily assimilated in the bay's large flow.
• Routine overland releases are limited at the Henderson facility by stormwater run-
on/run-off controls, and the low precipitation (11 cm/year) and gentle topographic slope
(0-2 percent) in the area. However, the facility is located in a 100-year floodplain and
is only 45 meters from a lake (Las Vegas Wash). Episodic overland run-off of
contaminants from the waste solids to the lake is possible in the unlikely event of a
flood. Any contaminants reaching the lake in this manner, if not sufficiently diluted,
could endanger aquatic life, restrict potential future uses of the lake, and pose a current
health risk via a drinking water intake 1,100 meters from the facility.
t
At the facility in Baltimore, MD, it is possible for contaminants to leach into the shallow ground
water located 9 meters below the surface and migrate into the Chesapeake Bay located 500 meters
downgradient. Because the precipitation in this area is high (108 cm) and the subsurface is relatively
impermeable, overland run-off due to surface erosion is also possible at this facility. If contaminants did reach
the bay via either of these routes, they would likely be rapidly diluted by the bay's large flow.
Air Release, Transport, and Exposure Potential
Only windblown dust particles from the chloride process waste solids are of concern for the air
pathway because all hazardous constituents of the waste are nonvolatile inorganics. The potential for dust to
be blown into the air from the surface impoundments and solids settling ponds is virtually non-existent because
the waste solids are submerged beneath liquids. When the settled solids and sludge are dredged, dried, and
accumulated in waste piles or landfills, airborne dust releases from these units could be possible. If releases
were to occur, chromium, and to a lesser extent, arsenic, thorium-232, and uranium-238 in the waste solids
particles could cause adverse health effects if inhaled, depending on the amount of dust emitted and the
proximity of receptors.
Release of dust particles from the landfills and waste piles to the air is possible because the waste
solids can be 20 micrometers (jim) or less in diameter (smaller than sand). In general, particles that are
<. 100 /tm in diameter are wind suspendable and transportable. Within this range, however, only particles that
are <. 30 /im in diameter can be transported for considerable distances downwind, and only particles that are
<. 10 fim in diameter are respirable. Therefore, a significant amount of the waste solids are expected to be
suspendable and transportable, and a small fraction is expected to be respirable.
-------
Chapter 13: Titanium Tetrachloride Production 13-15
For the chloride process waste solids accumulated in waste piles and landfills, site-specific factors
affecting the potential for airborne release and exposure include the exposed or uncovered surface area of the
units, wind speeds, number of days with precipitation (which affects the moisture content of the waste solids),
the use of dust suppression controls, and the proximity of the units to potentially exposed populations. These
factors are summarized on a site-specific basis in Exhibit 13-5 for the four facilities that manage the solids in
waste piles and landfills (New Johnsonville, Pass Christian, Savannah, and Henderson).
Considering these factors at the two sites with landfills, located in New Johnsonville, TN and Pass
Christian, MS, airborne releases of dust are considered possible at both sites, but it appears that people could
be exposed to such releases at only the Pass Christian facility. Neither facility practices dust suppression and
the number of days with rain, which suppresses dust naturally, is small at both facilities (92 and 98 days/yr).
As a result, the exposed surface of the waste solids is expected to be dry most of the time. It is not known
if inactive portions of the landfill are covered, but active portions are certainly uncovered and exposed to the
wind. Although there are short term gusts of stronger winds, average wind speeds range up to 3.4 and 4.2 m/s
at these facilities, which are strong enough to suspend the fine fraction of the solids. If such releases occur,
the potential for inhalation exposures could be significant at the Pass Christian facility because there is at least
one residence within a distance of 60 meters. However, the population within a mile of the facility is small
(30 people). Furthermore, at the Pass Christian facility, there is also a potential for food chain exposures
through deposition of panicles on food crops in the agricultural fields within a mile of the facility. There is
no known population within a mile of the New Johnsonville facility.
At the two facilities that manage the waste solids in piles, the potential for airborne releases and
exposures is high at the Henderson, NV facility and moderate at the Savannah, GA facility, based on the
following factors:
• At the Henderson facility, the waste solids pile covers 1.5 acres, is 6 meters high, and
is assumed to be uncovered. The waste solids in the pile are probably dry most of the
time because no dust suppression is conducted and the number of days with precipita-
tion is very small (21 days/yr). Average wind speeds at this facility range up to 4.1 m/s,
although there are certainly short-term gusts of stronger winds. If significant quantities
of dust are blown into the air, inhalation exposures could occur at the nearest residence,
located only 90 meters from the facility. The total population within 1.6 km (1 mile)
is 5,000.
• The waste solids pile at the Savannah facility covers an area of 1.5 hectares (3.7 acres),
is 1.2 meters high, and is assumed to be uncovered. Although the facility does not
practice dust suppression, there is a moderate number of days with rain (111 days/year)
that should help keep the surface of the waste solids moist part of the time. Annual
average wind-speeds range up to 3.4 m/s, which is sufficient to cause wind erosion of
fine panicles. If released, the wind-blown dust could lead to inhalation exposures at the
closest residence (400 meters from the facility), as well as exposures to the 500 people
that live within 1.6 km (1 mile).
Proximity to Sensitive Environments
As summarized in Exhibit 13-5, all nine titanium tetrachloride/dioxide facilities are located in
environments that are either vulnerable to contamination or have high resource value that may warrant special
consideration. In particular:
• The Antioch facility is located within 2.6 km (1.6 miles) of the critical habitat of an
endangered species, the Antioch Dunes Evening Primrose. Based on the conditions at
this site, the titanium waste solids at the Antioch facility could conceivably be a source
of ground-water contamination, but are not likely to be a significant source of surface
water or air contamination (see the preceding analysis). Considering the distance
between the site and the critical habitat, the waste solids should not pose a significant
hazard to the endangered species.
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13-16 Chapter 13: Titanium Tetrachloride Production
• The Edgemoor, Henderson, and Pass Christian facilities are located in 100-year
floodplains, which creates the potential for large, episodic releases of the waste solids
in the unlikely event of a large flood.
• The Henderson, Antioch, Hamilton, Baltimore, and Savannah facilities are located
within 1.6 km (one mile) of wetlands (defined here to include swamps, marshes, bogs,
and other similar areas). Wetlands are commonly entitled to special protection because
they create habitats for many forms of wildlife, purify natural water, provide flood and
storm damage protection, and afford a number of other benefits. Contamination from
titanium wastes produced at these sites could potentially cause adverse effects in
adjacent wetlands.
The Ashtabula facility is located in a fault zone. Although unlikely, there is some
potential for earthquake damage to the in-situ and recompacted clay liner of the on-site
surface impoundment, potentially allowing greater-than-expected releases of waste solids
contaminants to the subsurface.
• The New Johnsonville facility is located within 1.6 km (one mile) of a National Park.
Based on the preceding analysis of the release, transport, and exposure potential of this
facility, it is possible for waste solids contaminants to be blown into the air as dust from
the on-site landfill (the potential for significant releases to ground water and surface
water appears to be low). Any windblown contaminants produced from this landfill
could potentially cause adverse effects on the habitats and resources provided by the
National Park.
• The Savannah facility is located within 1.6 km (one mile) of a National Wildlife Refuge.
Based on the preceding analysis of potential release, transport, and exposure pathways,
there is a moderate potential for releases of waste solids contaminants from this site to
ground water, surface water, and air. Any contaminants released from this site could
potentially cause adverse effects on the habitats and resources provided by the National
Wildlife Refuge.
• The Henderson facility is located within 1.6 km (one mile) of a National Recreation
Area. As discussed in the preceding section, the primary potential release pathway at
this facility is windblown dust from the on-site waste pile. Any airborne contaminants
released from this waste pile could conceivably cause adverse effects on the habitats and
resources provided by the National Recreation Area.
Risk Modeling
Based on the preceding analysis of the intrinsic hazard of chloride process waste solids and the
potential for contaminants from the solids to be released into the environment, EPA ranked the waste solids
as having a relatively high potential at some facilities to cause human health and environmental risks
(compared to the other mineral processing wastes studied in this report). Therefore, the Agency used the
mocel "Multimedia Soils" (MMSOILS) to estimate ground-water, surface water, and air risks caused by the
existing waste solids management practices. Rather than model all nine facilities that currently generate and
manage the solids, EPA modeled only those facilities and release/exposure pathways that appear to pose the
greatest concern in order to develop reasonable upper bound estimates of the risks across the industry.
Ground-Water Risks
EPA modeled potential releases to ground water from the surface impoundments used to accumulate
waste solids at the Kerr-McGee facility in Hamilton, MS. This facility was selected for ground-water modeling
because it appears to have the highest ground-water release and exposure potential of all the active titanium
tetrachloride facilities, based on the above analysis of management practice and environmental setting
characteristics. Using median contaminant concentrations measured in waste solids from the other titanium
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Chapter 13: Titanium Tetrachloride Production 13-17
facilities,15 combined with site-specific data with respect to waste solid quantities, impoundment design
features, and hydrogeologic characteristics at the Hamilton facility, EPA predicted the concentrations of nine
constituents (arsenic, chromium, cobalt, copper, iron, lead, manganese, nickel, and silver) at a variety of
downgradient locations. The downgradient distances that were modeled included the property boundary and
nearest surface water body (60 meters), the nearest existing residence that could have a drinking water well
(700 meters), and, to analyze how far the contaminant plume might migrate, a distance of 1,000 meters. For
each constituent, the Agency compared the predicted concentrations at these locations to cancer risk levels,
threshold concentrations for noncancer effects, drinking water maximum contaminant levels (MCLs), and
guidelines for irrigation and livestock waters recommended by the National Academy of Sciences (NAS).
For all of the constituents except arsenic and cobalt, the predicted concentrations at each of the
downgradient distances modeled (including the property boundary roughly 60 meters downgradient) were at
least two orders of magnitude below the various criteria. The predicted concentration of arsenic at the
property boundary poses a lifetime cancer risk of SxlO"4 (i.e., the chance of getting cancer would be
approximately 3 in 10,000 if the water was ingested over a 70-year lifetime). This predicted arsenic
concentration, however, is only 0.2 times the MCL. It is unlikely that anyone would actually drink the ground
water at or very near the property boundary at this facility because the impoundments border McKinley Creek,
and it is unlikely that anyone would place a drinking water well between the impoundments and McKinley
Creek. The nearest existing residence that conceivably could have a drinking water well is located about 700
meters downgradient. Assuming that the ground water leaving the Hamilton site migrates beneath McKinley
Creek and eventually to this residence, rather than discharging directly into the creek, the concentration of
arsenic at this distant location would pose a very low lifetime cancer risk, less than IxlO"10.
The predicted concentration of cobalt did not exceed any of the criteria at any of the downgradient
distances, but it was equal to 0.8 times the NAS guideline for irrigation water at the property boundary.
Concentrations of cobalt in excess of this guideline have been shown to be toxic to a variety of plants,
including tomatoes, peas, beans, oats, rye, wheat, barley, and corn. Although the Hamilton site is located in
an agricultural area, this cobalt contamination is not likely to cause significant impacts because: the maximum
predicted concentration at a point where the ground water conceivably could be used is below the criterion,
the contamination may discharge directly into McKinley Creek where it would be further diluted, and the
predicted concentration of cobalt in ground water at the nearest downgradient residence that could have a well
is more than two orders of magnitude below the NAS guideline.
As a "worst-case" analysis, EPA estimated the downgradient concentrations of chromium and lead
assuming that the waste solids leachate from the impoundments at Hamilton contain the highest
concentrations observed in any of the available sample results, 100 mg/1 chromium and 31 mg/1 lead. This
chromium concentration exceeds the EP toxic level by a factor of 20 and the lead concentration exceeds the
EP toxic level by a factor of 6. Even when these maximum leachate concentrations were used, the ground-
water concentrations of both chromium and lead at the property boundary were predicted to be more than
two orders of magnitude below their respective criteria.
Surface Water Risks
To evaluate surface water risks, EPA again considered the Kerr-McGee facility in Hamilton, MS.
Having large impoundments within 60 meters of a creek, this facility has a relatively high potential (compared
to the other eight titanium facilities) of contaminating surface water via releases to ground water. In order
to assess the possible combined effect of stormwater erosion into surface water, the Agency conservatively
assumed that, after closure, the impoundments were filled with waste solids but not covered or equipped with
run-off controls.
15 No data are available on the composition of waste solids at the Hamilton facility.
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13-18 Chapter 1.3: Titanium Tetrachloride Production
Using this conservative scenario, EPA predicted the concentration of the following waste solid
contaminants in McKinley Creek after they have been fully mixed in the creek's flow: arsenic, chromium,
cobalt, copper, iron, lead, manganese, nickel, silver, and thallium. For each constituent, the Agency compared
the predicted concentrations to cancer risk levels, threshold concentrations for noncancer effects, drinking
water MCLs, freshwater ambient water quality criteria, and the NAS recommended guidelines for irrigation
and livestock. Note that the methodology used here does not account for removal of pollutants via drinking
water treatment, and thus overstates the risk through that pathway.
Even with this conservative approach, EPA's risk model predicted that the average annual flow of
McKinley Creek is capable of effectively assimilating the annual load of contaminants from the on-site
impoundments. The predicted concentrations of all the constituents were more than two orders of magnitude
below the various criteria. The predicted concentration of arsenic in the creek would pose a very low lifetime
cancer risk, about IxlO"8, and is more than five orders of magnitude below the MCL. With the exception of
arsenic and cobalt, essentially 100 percent of the contamination in McKinley Creek was predicted to be caused
by the erosion of fine particles of the waste solids (seepage of contaminants into ground water with subsequent
discharge into the creek resulted in a negligible pollutant loading). For arsenic and cobalt, approximately 80
percent of the contaminant load to the stream was through ground-water discharge, while only 20 percent was
due to erosion.
As was done in the assessment of ground-water risks, EPA analyzed how these risk estimates would
change if, instead of using median contaminant concentrations, the concentrations of chromium and lead in
leachate from the impoundment were assumed to equal the maximum concentrations observed in EP leach
tests (which exceeded the EP-toxic levels). Using these maximum concentrations would increase the loading
of chromium to the creek, but not enough to make the surface water concentration approach hazardous levels.
Similarly, increasing the lead concentration in the leachate had no effect on the predicted concentration in
McKinley Creek because essentially all of the lead contamination was predicted to enter the creek by erosion
rather than seepage through ground water.
None of the constituents that were modeled are recognized as having the potential to biomagnify
(concentrate in the tissue of organisms higher in the food chain). Arsenic and chromium can bioaccumulate
slightly in the tissue of freshwater fish that may be ingested by humans. However, even under worst-case
exposure assumptions, the predicted concentrations of these contaminants are very unlikely to cause adverse
health effects through the fish ingestion pathway.
Air Risks
Tb analyze air risks, EPA modeled the release of windblown dust from the waste solids pile and the
associated inhalation risks at the facility in Henderson, NV Of the nine active titanium facilities, this facility
has the greatest potential to pose air risks because the solids are managed in a large pile that is uncovered,
exposed to relatively high winds, and dry most of the time (as described in the above analysis of release,
transport, and exposure potential). There is also a residence located just 90 meters downwind and 5,000
people live within one mile; all could be exposed to any windblown dust. Using the median constituent
concentrations and site-specific data with respect to waste quantities, existing management practices, and
atmospheric dispersion conditions, EPA estimated the release and inhalation risks of arsenic, chromium,
thorium-232, and uranium-238, which are the primary constituents of concern through the air pathway, based
on the preceding analysis of the waste solids' composition.
At the residence of the maximum exposed individual (roughly 90 meters downwind from the waste
pile), EPA predicted airborne concentrations of arsenic, chromium, thorium-232, and uranium-238. Total
lifetime cancer risk, from all four constituents combined, is IxlO"8. Most of this risk was estimated to be
caused by chromium, conservatively assumed here to exist in its carcinogenic hexavalent form. If the maximum
waste solids concentrations of these constituents were used in the model instead of median concentrations,
the total lifetime cancer risk would be 2xlO'7; this represents the maximum inhalation risk expected across the
industry. The predicted concentrations of these contaminants 800 meters (0.5 mile) downwind in the
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Chapter 13: Titanium Tetrachloride Production 13-19
predominant wind direction poses a lifetime cancer risk of 3xlO'9. This risk approximates the average
inhalauon risk of the 5,000 people living within 1.6-km (1 mile) of the facility.
13.3.2 Damage Cases
State and EPA regional files were reviewed in an effort to document the performance of waste
management practices for chloride process waste solids from titanium tetrachloride production at the active
titanium facilities, and at two inactive titanium facilities: Ormet in Albany, Oregon; and duPont in La Porte,
Texas.16 The file reviews were combined with interviews with State and EPA regional regulatory staff.
Through these case studies, EPA found no documented environmental damages clearly attributable to
management of chloride process waste solids from titanium tetrachloride production at any of these facilities.
Some cases of documented damage attributable to other wastes were identified, however, and it is possible,
though not demonstrated, that waste solids have contributed to these observed damages.
13.3.3 Findings Concerning the Hazards of Chloride Process Waste Solids
Available data on the composition of the waste solids show that the solids contain over 17
constituents that are present in concentrations that exceed the screening criteria. The contaminants that
appear to pose the greatest potential threat are arsenic, chromium, iron, lead, manganese, vanadium, and
silver. Based on available data and professional judgment, EPA does not believe that the waste solids exhibit
the hazardous waste characteristics of corrosivity, ignitability, or reactivity. However, using the EP leach test,
chromium exceeded the EP toxicity regulatory level in 3 of 16 samples, and lead exceeded the EP toxicity
regulatory level in 1 of 16 samples. Lead and chromium concentrations measured using the SPLP test also
exceeded the EP toxicity regulatory levels, by roughly the same margin as the EP test results. In addition, the
waste solids contain uranium-238, thorium-232, and their decay products in concentrations that could pose an
unacceptably high radiation risk if the solids were allowed to be used in an unrestricted fashion.
Based on an examination of the characteristics of each site, EPA believes that there is a potential for
waste solids contaminants to migrate into ground-water, surface water, and air at the active titanium facilities.
For example:
• There is a relatively high potential for ground-water contamination from the
impoundments at the Antioch, CA and Hamilton, MS facilities because the solids are
submerged beneath liquids that could hydraulically force contaminants into the
subsurface, some of the impoundments may not be equipped with liners or leachate
collection systems, the ground water is shallow (1 to 6 m deep), and the subsurface is
highly permeable.
• Most of the facilities are located within 100 meters of a river or creek. At those sites
with a relatively high ground-water release potential, it is likely that any ground-water
contamination would discharge directly into these water bodies. In addition, the particle
size of the solids is fairly small and thus it is possible for contaminants to erode into
nearby creeks and rivers when the solids are managed in landfills and waste piles.
• The small particle size of the solids is conducive to wind erosion and transport, and the
solids are managed at four facilities in piles or landfills that are exposed to the wind.
The potential for such airborne releases appears greatest at the waste solids pile at the
Henderson, NV facility, where the solids are expected to remain dry most of the time
and winds are relatively strong.
However, based on site-specific modeling results, the Agency predicts that the environmental
contamination that could occur is not likely to cause significant adverse impacts, as currently managed at the
existing facilities. This is corroborated by the lack of documented cases of damage attributable to the waste
Facilities are considered inactive for purposes of this report if they are not currently engaged in primary mineral processing.
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13-20 Chapter 13: Titanium Tetrachloride Production
solids at the existing facilities. The environmental conditions at the Hamilton facility are most conducive to
ground- and surface water contamination. Using these facility conditions as the basis for modeling, EPA
predicts that the concentration of arsenic in ground water at the plant boundary (roughly 60 meters
downgradient) could pose a lifetime cancer risk of SxlCT4. In terms of current exposures, however, nobody
presently drinks the ground water at this location, and the predicted arsenic concentration at the nearest
existing residence that could have a drinking water well would pose a cancer risk of less than IxlO"10. Any
contamination of the water table aquifer at this site and any stormwater run-off are likely to discharge directly
into adjacent McKinley Creek. The predicted annual average concentrations of arsenic and other contaminants
in this creek are more than two orders of magnitude below various hazard criteria. EPA believes the ground-
water and surface water risks at the other titanium facilities would be comparable if not lower than those
predicted for the Hamilton facility.
At the Henderson, NV facility, EPA predicts a maximum lifetime cancer risk of 2xlO~7 caused by the
release and inhalation of windblown dust. Again, the inhalation risks at the other facilities are probably even
lower.
13.4 Existing Federal and State Waste Management Controls
13.4.1 Federal Regulation
Under the Clean Water Act, EPA has the responsibility for setting "effluent limitations," based on
the performance capability of treatment technologies. These "technology based limitations," which provide the
basis for the minimum requirements of NPDES permits, must be established for various classes of industrial
discharges, including a number of ore processing categories.
Permits for mineral processing facilities may require compliance with effluent guidelines based on best
practicable control technology currently available (BPT) or best available technology economically achievable
(BAT). BPT effluent limitation guidelines relevant to discharges from the production of titanium dioxide by
oxidizing titanium tetrachloride include:
TITANIUM DIOXIDE-CHLORIDE PROCESS (40 CFR 415.222(b»
Pollutant
Total Suspended Solids
Total Chromium
PH
Dally Maximum
23 Kg/kkg
0.057 Kg/kkg
6-9
Monthly Average
6.4 Kg/kkg
0.030 Kg/kkg
6-9
TITANIUM DIOXIDE-CHLORIDE-ILMENITE PROCESS (40 CFR 415.222(c))
Pollutant
Total Suspended Solids
Total Chromium
Total Nickel
PH
Dally Maximum
35 Kg/kkg
0.12 Kg/kkg
0.072 Kg/kkg
6-9
Monthly Av^raQt
9.6 Kg/kkg
0.053 Kg/kkg
0.035 Kg/kkg
6-9
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Chapter 13: Titanium Tetrachloride Production 13-21
BAT effluent limitation guidelines for the above mentioned processes require that discharges not
exceed the limitations set forth for chromium in 40 CFR 415.222 (b) and (c), and further that the discharge
of nickel not exceed the levels established in 40 CFR 415.222 (c) for the dioxide-chloride-ilmenite process.
New source performance standards for these two processes include the following limitations (40 CFR
415.225 (b) and (c)):
TITANIUM DIOXIDE-CHLORIDE PROCESS
Pollutant
Total Suspended Solids
Total Iron
Total Chromium
pH
Dally Maximum
14 Kg/kkg
0.52 Kg/kkg
0.023 Kg/kkg
6-9
Monthly Average
4 Kg/kkg
0.016 Kg/kkg
0.012 Kg/kkg
6-9
TITANIUM DIOXIDE-CHLORIDE-ILMENITE PROCESS
Pollutant
Total Suspended Solids
Total Iron
Total Chromium
Total Nickel
PH
Dally Maximum
8.4 Kg/kkg
0.32 Kg/kkg
0.014 Kg/kkg
0.020 Kg/kkg
6-9
Monthly Average
2.4 Kg/kkg
0.096 Kg/kkg
0.0072 Kg/kkg
0.010 Kg/kkg
6-9
13.4.2 State Regulation
The nine facilities in the titanium tetrachloride sector generating chloride process waste solids are
located in eight states: California, Delaware, Georgia, Maryland, Mississippi, Nevada, Ohio, and Tennessee.
For the purposes of this report, four of these states, Delaware, Mississippi, Ohio, and Tennessee, were studied
in detail (see Chapter 2 for a discussion of the methodology used to select states for detailed regulatory study).
Two facilities are located in Mississippi, while a single facility is located within each of the three remaining
study states.
As a general overview, all of the eight states with titanium tetrachloride facilities except California
exclude mineral processing wastes from their hazardous waste regulations. California has hazardous waste
provisions for mine and mill tailings under certain circumstances, though it is not clear whether the state
applies these provisions to the chloride process waste solids generated within its borders. Of the study states,
Delaware, Tennessee, and Ohio have solid waste regulations that address and regulate the disposal of solid
wastes from mineral processing, while Mississippi exempts on-site disposal of Industrial solid waste from any
requirements under the state's solid waste regulations. All four of the study states have approved NPDES
programs and issue permits for all point-source discharges to surface waters. All four states also have air
quality regulations, but none that are applicable to chloride process waste solids disposal practices.
Ohio and Tennessee each have a single titanium tetrachloride facility that generates chloride process
waste solids.17 The solid waste regulations of both of these states apply to mineral processing wastes.
17 Ohio's SCM facility at Ashtabula actually consists of two plants, Ashtabula 1 and II.
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13-22 Chapter 13: Titanium Tetrachlorlde Production
Because Ohio's regulations include exemptions for wastes that are reused or recycled, however, the state has
not required a solid waste permit of the Ashtabula facility, which recycles all of its chloride process waste
solids that are not shipped off-site for disposal. Ohio's regulations do not include specific storage
requirements for non-putrescible wastes, regardless of the storage time before the waste is actually recycled.
Similarly, although Tennessee requires its titanium tetrachloride facility to maintain a solid waste disposal
permit, the state has focused its regulatory efforts primarily on municipal solid waste landfills. Both Ohio and
Tennessee recently revised their regulations and appear to be preparing to regulate mineral processing wastes
more comprehensively. If the states implement the regulations as anticipated, both titanium tetrachloride
facilities could be required to upgrade their disposal management practices to include activities such as the
installation of covers, liners, and ground-water monitoring, or to ship their wastes off-site to properly
permitted landfills. Both Ohio and Tennessee have approved NPDES programs and require permits for all
discharges to surface waters. Finally, neither Ohio nor Tennessee has applied fugitive dust emission controls
to their facilities' chloride waste solids disposal activities.
Two titanium tetrachloride facilities are active in the State of Mississippi. Mississippi's solid waste
regulatory program exempts mineral processing wastes that are generated, processed, and disposed of on-site.
Because both of Mississippi's facilities dispose of their chloride process waste solids on-site, therefore, neither
facility has been required to obtain a solid waste disposal permit. Mississippi does have an approved NPDES
program, however, and requires NPDES permits of both facilities that include provisions for effluent
monitoring/characterization. One of the facilities is permitted to discharge its process wastewater to surface
waters while the second facility injects its process wastewater into the ground via three on-site deep wells.
Mississippi has not applied fugitive dust emission control requirements to the chloride waste disposal activities
of its titanium tetrachloride facilities.
A single facility is active in the State of Delaware. Of the four study states, Delaware appears to most
active in regulating its single titanium tetrachloride facility under its solid waste regulations. The state has
required that the facility maintain a permit and meet a variety of environmental criteria such as the collection,
treatment, and disposal of leachate and the installation of liners. Delaware recently revised its solid waste
regulations, though the changes appear to be more administrative than substantive. As with the other study
states, Delaware has an approved NPDES program and has required that the facility maintain a discharge
permit for its on-site surface impoundment. Finally, as with the other study states, Delaware has not applied
fugitive dust emission controls to its facilities' chloride process solid waste disposal activities.
In summary, all of the four study states with titanium tetrachloride facilities exclude the management
and disposal of chloride process waste solids from hazardous waste regulation. Of these four states, Delaware
appears to be most actively regulating these wastes under its solid waste regulations. In contrast to apparently
limited regulation in the past, however, both Ohio and Tennessee recently revised their solid waste regulations
and appear to be preparing to regulate these wastes more stringently. All four study states have approved
NPDES programs and have applied permit requirements to the titanium tetrachloride facilities within their
borders that discharge to surface waters. Finally, none of the states apply fugitive dust emission controls to
the disposal of chloride process waste solids.
13.5 Waste Management Alternatives and Potential Utilization
In the following paragraphs, the Agency provides a brief summary of information collected on
alternative waste management practices and potential areas of utilization.
Recycling of the waste solids is the primary management alternative to the current disposal practice
of neutralization and surface impoundment/landfill disposal. Laboratory tests have shown that the solid
residue (approximately one-half of the sludge by weight) generated during the production of titanium
tetrachloride from rutile, can be agglomerated and recycled. Recycling the solid residue would reduce the
volume of waste requiring disposal, and there is reason to believe that the addition of the residue to the rutile
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Chapter 13: Titanium Tetrachloride Production 13-23
charge could improve the chlorination characteristics of the feed materials.18 However, while many
producers of titanium tetrachloride have tried to develop methods of recycling their waste solids, as of 1987,
no facilities were reported to be routinely recycling their waste solids.19 Most facilities that have tried to
recycle the waste solids have experienced operational difficulties (e.g., corrosion or reactor upsets) which
caused them to abandon recycling.
Another management alternative is the recovery of columbium, tantalum, zirconium, and titanium
from the waste solids. Laboratory tests have demonstrated the technical feasibility of recovering these metals
(on a bench-scale) from the waste solids generated by the Timet (Henderson, Nevada), SCM (Ashtabula,
Ohio), Kerr-McGee (Hamilton, Mississippi), and E.I. duPont (New Johnsonville, Tennessee) facilities. The
process involves a combination of water leaching, pressure hydrolysis, and solvent extraction.20 However,
it is not known if this process is being used by any of the facilities, or if a full-scale application of the process
would be technically or economically feasible at any of the titanium tetrachloride facilities.
13.6 Cost and Economic Impacts
Section 8002(p) of RCRA directs EPA to examine the costs of alternative practices for the
management of the special wastes considered in this report. EPA has responded to this requirement by
evaluating the operational changes that would be implied by compliance with three different regulatory
scenarios, as described in Chapter 2. In reviewing and evaluating the Agency's estimates of the cost and
economic impacts associated with these changes, it is important to remember what the regulatory scenarios
imply, and what assumptions have been made in conducting the analysis.
The focus of the Subtitle C compliance scenario is on the costs of constructing and operating
hazardous waste land disposal units. Other important aspects of the Subtitle C system (e.g., corrective action)
have not been explicitly factored into the cost analysis. Therefore, differences between the costs estimated for
Subtitle C compliance and those under other scenarios (particularly Subtitle C-Minus) are less than they might
be under an alternative set of conditions (e.g., if most affected facilities were not already subject to Subtitle C).
The Subtitle C-Minus scenario represents, as discussed above in Chapter 2, the minimum requirements that
would apply to any of the special wastes that are ultimately regulated as hazardous wastes; this scenario does
not reflect any actual determinations or preliminary judgments concerning the specific requirements that would
apply to ;*ny such wastes. Further, the Subtitle D-Plus scenario represents one of many possible approaches
to a Subtitle D program for special mineral processing wastes, and has been included in this report only for
illustrative purposes. The cost estimates provided below for the three scenarios considered in this report must
be interpreted accordingly.
In accordance with the spirit of RCRA §8002(p), EPA has focused its analysis on impacts on the firms
and facilities generating the special wastes, rather than on net impacts to society in the aggregate. Therefore,
the cost analysis has been conducted on an after-tax basis, using a discount rate based on a previously
developed estimate of the weighted average cost of capital to U.S. industrial firms (9.49 percent), as discussed
in Chapter 2. Waste generation rate estimates (which are directly proportional to costs) for the period of
analysis (the present through 1995) have been developed in consultation with the U.S Bureau of Mines.
In this section, EPA first outlines the way in which it has identified and evaluated the waste
management practices that would be employed under different regulatory scenarios by facilities producing
titanium tetrachloride (dioxide). Next, the section discusses the cost implications of requiring these changes
18 Merrill, C.C., M.M. Wong, and D.D. Blue, Benefication of Titanium Chlorination Residues: Preliminary Study. Report of
Investigations 7221, Bureau of Mines, U.S. Department of Interior, 1969, p. 5.
19 Krispar Technologies, Inc., Study on Titanium Chlorination Solid Wastes. Minerals & Materials Research Division, Bureau of Mines,
U.S. Department of Interior, October 30,1987, p. 145.
20 Merrill, CC. and D.E. Couch, Separation of Columbium. Tantalum. Titanium, and Zirconium from Titanium Chlorination Residues,
Report of Investigations 7671, Bureau of Mines, U.S. Department of Interior, 1970.
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13-24 Chapter 13: Titanium Tetrachloride Production
to existing waste management practices. The last part of the section discusses and predicts the ultimate
impacts of the increased waste management costs faced by the facilities.
13.6.1 Regulatory Scenarios and Required Management Practices
Based upon the information presented above, EPA believes that waste solids generated in the
production of titanium tetrachloride at some facilities exhibit the hazardous waste characteristic of EP toxicity.
Accordingly, the Agency has estimated the costs associated with regulation under Subtitle C of RCRA, as well
as with two somewhat less stringent regulatory scenarios, referred to here as "Subtitle C-Minus" and
"Subtitle D-Plus," as previously introduced in Chapter 2, and as described in specific detail below.
EPA has adopted a conservative approach in conducting its cost analysis for the wastes generated by
the titanium tetrachloride production industry. The Agency has assumed that the chloride process waste solids
would exhibit EP toxicity at all facilities unless actual sampling and analysis data demonstrate otherwise.
EPAs waste sampling data indicate that the waste solids do not exhibit any characteristics of hazardous waste
at five of the nine facilities that generate the material. The Agency's cost and impact analysis is therefore
limited to four facilities.
Subtitle C
Under Subtitle C standards, generators of hazardous waste that is managed on-site must meet the
rigorous standards codified at 40 CFR Part 264 for hazardous waste treatment, storage, and disposal facilities.
Because chloride process waste solids are solid (sludge), non-combustible materials, and because under full
Subtitle C regulation, hazardous wastes cannot be permanently disposed of in waste piles, EPA has assumed
in this analysis that the ultimate disposition of chloride process waste solids would be in Subtitle C landfills,
either on-site or, if sites for land disposal are not available, off-site. Because chloride process solids are
typically generated as a sludge following treatment or settling in an impoundment and because of restrictions
concerning liquids in landfills, the Agency has assumed that the facilities would also construct storage surface
impoundments (two per facility) to manage the sludge and prepare it for disposal. Each impoundment is
assumed to have the capacity to hold one half of the waste generated annually. These impoundments would
be used to settle the solids; periodically (collectively for half the year) solids are settled in one of the two
impoundments. The remainder of the year the solids are routed to the second impoundment, while the sludge
in the first impoundment is dried and stabilized with cement. The stabilized sludge is then dredged and
landfilled. Facilities that currently ship their waste solids off-site for disposal (e.g., SCM-Ashtabula) are
assumed to construct their own on-site waste management units, because this would be considerably less costly
than shipment of the chloride process waste solids to a commercial hazardous waste management facility, given
the volumes of waste involved.
Subtitle C-Minus
A primary difference between full Subtitle C and Subtitle C-Minus is the facility-specific application
of requirements based on risk potential at each site. Under the C-Minus scenario, as well as the
Subtitle D-Plus scenario described below, the degree of potential risk of contaminating ground-water resources
was used as a decision criterion in determining what level of design standards (e.g., liner and closure cap
requirements) would be necessary to protect human health and the environment All four facilities generating
potentially hazardous chloride process waste solids were determined to have a high potential to contaminate
ground-water resources. When risk to ground water is high, facilities are assumed to be required to manage
the waste in disposal impoundments equipped with composite liners. As none of the facilities currently
operate adequately lined disposal units, all four facilities would be required to build new units under the
Subtitle C-Minus scenario. In addition to the composite liners, the facilities are required to install run-on/run-
off controls and groundwater monitoring wells; both practices must be continued through the post-closure care
period. In addition, the units must undergo formal closure, including a cap of topsoil and grass/synthetic
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Chapter 13: Titanium Tetrachloride Production 13-25
liner/clay (three foot thickness). Post-closure care must be maintained (e.g., mowing and general cap
maintenance, and groundwater monitoring) for a period of thirty years.
In addition to the cost differences between full Subtitle C and Subtitle C-Minus that are attributable
to the design, construction, and operation of waste management units, a potentially significant cost difference
arises from the relaxation of the sludge stabilization/solidification step that EPA has included in the full
Subtitle C scenario to account for probable future Land Disposal Restrictions. Under the Subtitle C-Minus
scenario, sludges are assumed to be disposed without stabilization/solidification. This implies a savings of the
treatment equipment and variable costs, and the cost of disposing the greater (50 percent) quantity of
stabilized material, in comparison with the full Subtitle C scenario. In addition, the treatment (i.e., settling)
ponds used to separate sludge and entrained water prior to cementation are no longer required.
Subtitle D-Plus
As under both Subtitle C scenarios, facility operators under the Subtitle D-Plus scenario would be
required to ensure that hazardous contaminants do not escape into the environment. Like the Subtitle C-
Minus scenario, facility-specific requirements are applied to allow the level of protection to increase as the
potential risk to groundwater increases. Because the four titanium tetrachloride facilities with potentially
hazardous chloride process waste solids all have high potential to contaminate groundwater resources, the
facilities are assumed to require disposal in impoundments lined with composite liners, which, as pointed out
above, none of the facilities currently have. Therefore, EPA has assumed that the facilities would construct
new units with composite liners, and install run-on/run-off controls and groundwater monitoring wells;
maintenance of these systems must be continued through the post-closure care period under this scenario, as
in the others. In addition, the units must undergo formal closure, including a cap of topsoil and grass over
a synthetic liner on three feet of clay. Post-closure care must be maintained (e.g., leachate/run-off collection
and treatment, cap maintenance, and groundwater monitoring) for a period of thirty years. Under this
scenario, EPA has assumed that the SCM-Ashtabula facility would be required to construct on-site
management units that meet the Subtitle D-Plus technical standards, rather than continue to ship its chloride
process waste solids off-site for disposal. In this way, adequate protection of human health and the
environment would be ensured.
As in the Subtitle C-Minus scenario, EPA has not included a sludge stabilization/solidification step
in the waste management sequence. This results in considerable savings over waste management under the
full Subtitle C scenario.
13.6.2 Cost Impact Assessment Results
Results of the cost impact analysis for the titanium tetrachloride sector are presented by facility and
regulatory scenario in Exhibit 13-6. Under the Subtitle C scenario, annualized incremental regulatory
compliance costs for the sector are estimated at more than $28.0 million. The costs range from S5.4 to S9.4
million greater than baseline costs (4 to 29 times larger than baseline). Annualized capital costs range from
$14 to $4.9 million over baseline, representing about one half of the total annual costs. Total initial
compliance-related capital expenditures are $98.8 million, ranging from $16.0 million to $33.2 million.
Under the facility-specific requirements of the Subtitle C-Minus scenario, costs of regulatory
compliance are, for the sector, about eleven percent of the full Subtitle C costs. The sector-wide annualized
compliance cost is about $3.2 million greater than baseline (roughly twice the baseline costs). Total initial
capital costs are estimated at about $24.8 million, ranging from $3.0 to $7.9 million. Overall, the primary
differences in costs are due to decreased capital construction costs and relaxation of the sludge stabilization/
solidification requirements; the difference in capital costs is primarily related to the configuration of the
landfill liners, leachate collection/detection systems, and closure caps. Other waste management elements
having significant cost implications (e.g., non-liner related capital construction costs, operating costs, ground-
water monitoring) are identical under these two regulatory scenarios.
-------
Exhibit 13-6
Compliance Cost Analysis Results for Management of
Titanium Tetrachloride Process Waste Solids*")
Facility
duPont - New Johnsonville. TN
SCM Chemicals - Ashtabula. OH
Ker-McQee • Hamilton, MS
Tlmet - Henderson, NV
Total:
Average:
Baseline Waste
Management Cost
Annual Total
($000)
2.023
1,934
591
365
4.913
1,228
Incremental Coat* of Regulatory Compliance
Annual
Total
($000)
9.496
5.986
5,448
7,134
28,064
7.018
Subtitle C
Total
Capital
($000)
33.217
26.569
16,086
22,981
98,853
24,713
Annual
Capital
($000)
4,956
3.965
2.400
3.429
14,750
3,688
Subtitle C-Mlnus
Annual
Total
($000)
142
623
896
1,545
3,206
801
Total
Capital
($000)
7,914
7.206
3,018
6.645
24.783
6,196
Annual
Capital
($000)
1,181
1.075
450
992
3,698
924
Subtitle D-Plua
Annual
Total
($000)
142
623
896
1,540
3.201
800
Total
Capital
($000)
7,914
7.206
3,018
6.645
24,783
6.196
Annual
Capital
($000)
1,181
1,075
450
992
3.698
924
IO
at
o
U)
i
!
n
o"
a
O
(a) Values reported In this table are those computed by EPA's cost estimating model, and are Included for Illustrative purposes. The data, assumptions, and computational
methods underlying these values are such that EPA believes that the compliance cost estimates reported here are precise to two significant figures.
Facilities modeled as generating potentially hazardous waste include those for which no sampling data exists.
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Chapter 13: Titanium Tetrachloride Production 13-27
Costs under the Subtitle D-plus regulatory scenario are virtually identical to those under Subtitle C-
minus scenario, the only difference being slight difference in permit costs at one facility,
13.6.3 Financial and Economic Impact Assessment
To evaluate the ability of affected facilities to bear these regulatory compliance costs, EPA conducted
an impact assessment consisting of three steps. First, the Agency compared the estimated costs to several
measures of the financial strength of each facility and thereby generated financial impact ratios, to assess the
magnitude of the financial burden that would be imposed in the absence of changes in supply, demand, or
price. Next, in order to determine whether compliance costs could be distributed to (shared among) other
production input and product markets, EPA conducted a qualitative evaluation of the salient market factors
that affect the competitive position of domestic producers. Finally, the Agency combined the results of the
first two steps to arrive at predicted ultimate compliance-related economic impacts on the titanium
tetrachloride (dioxide) industry. The methods and assumptions used to conduct this analysis are described in
Chapter 2.
Financial Ratio Analysis
EPA believes that Subtitle C regulation would impose potentially significant financial impacts on all
four potentially facilities in the titanium tetrachloride industry. As shown in Exhibit 13-7, the annualized
capital costs associated with waste management under Subtitle C as a percentage of annual investment exceed
the five percent threshold at all four facilities, ranging from 18 to 49 percent. Annualized incremental costs
as a percentage of value of shipments and value added exceed the screening criteria for significant impacts in
all cases; these ratios range from just under 2.0 percent to 5.3 percent.
Financial impacts under the Subtitle C-Minus scenario are significantly lower than under full
Subtitle C. The annualized capital costs associated with waste management under Subtitle C-Minus as a
percentage of annual investment again exceed the five percent threshold for three of the four affected firms.
Annualized incremental costs as a percentage of value of shipments and value added continue to exceed the
threshold for potentially significant impacts only at the Timet facility where costs ratio results are just over
one percent.
Under the Subtitle D-Plus scenario, as discussed above, costs, and therefore impacts, are nearly
identical to those under the Subtitle C-Minus scenario.
Market Factor Analysis
General Competitive Position
The U.S. is very competitive in titanium dioxide production on a worldwide basis. Some of the
producers, such as duPont, are also partially integrated through the raw material stage. The fact that very few
producers worldwide are fully integrated (with the exception of Norway and some Australian producers) puts
manufacturers on a roughly equal basis in terms of raw material costs. Indeed, the feet that most producers
are largely dependent on Australian rutile, ilmenite, and titaniferrous slags has led to strong price increases
for these raw materials over the last ten years. The U.S. plants that previously produced titanium dioxide by
the higher cost sulfate route have largely been eliminated or updated.
In terms of conversion to the chloride process, the U.S. is considerably more advanced than other
countries and therefore will not undergo the capital expenditures for conversion that many other countries
will likely be required to make over the next decade in order to remain cost-competitive. The fact that the
U.S. is efficient (has comparatively low processing costs) and also a pioneer of chloride process technology
(most notably duPont) results in the U.S. being very competitive on a worldwide basis.
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13-28 Chapter 143: Titanium Tetrachloride Production
Exhibit 13-7
Significance of Regulatory Compliance Costs for Management of
Titanium Tetrachloride Chloride Process Waste Solids*8
Facility
Subtitle C
duPont - New Johnsonville, TN
SCM Chemicals - Ashtabula, OH
Kerr-McGee - Hamilton, MS
Timet - Henderson, NV
Subtitle C-Minus
duPont - New Johnsonville, TN
SCM Chemicals - Ashtabula, OH
Kerr-McGee - Hamilton, MS
Timet - Henderson, NV
Subtitle D-Plus
duPont - New Johnsonville, TN
SCM Chemicals - Ashtabula, OH
Kerr-McGee - Hamilton, MS
Timet - Henderson, NV
CC/VOS
1.7%
2.5%
3.2%
5.1%
0.0%
0.3%
0.5%
1.1%
0.0%
0.3%
0.5%
1.1%
CC/VA
1.9%
3.2
4.1%
5.3%
0.0%
0.3%
0.7%
1.2%
0.0%
0.3%
0.7%
1.1%
IR/K
18.0%
33.6%
28.2%
49.0%
4.3%
9.1%
5.3%
14.2%
4.3%
9.1%
5.3%
14.2%
CC/VOS = Compliance Costs as Percent of Sales
CC/VA = Compliance Costs as Percent of Value Added
IR/K = Annualized Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported in this table are based upon EPA's compliance cost estimates. The Agency believes that these
values are precise to two significant figures.
Potential for Compliance Cost Pass-Through
Labor Markets
There is a possibility for some reduction in wages, as past reductions in salary have not been
comparable to that of the general mineral processing industry. The need to keep highly-skilled professionals
(to maintain and expand the technological advantage of domestic producers), however, means that lower wages
may cause personnel losses to competitors in other chemical industry segments.
Supply Markets
The U.S. does utilize some ilmenite, even though most plants have converted to the chloride process,
which cannot use ilmenite directly as a feedstock (the sulfate process can use ilmenite directly). A large
portion of the ilmenite brought to the U.S. is as a feedstock for the Kerr-McGee synthetic rutile plant in
Hamilton, Mississippi, and is obtained under long-term contract
DuPont also utilizes some ilmenite in its process, even though it uses chloride route processing, but
these are largely altered ilmenites from domestic and imported (long-term contract) sources. Most U.S. plants
need slag, rutile, or synthetic rutile as a feedstock. Consequently, U.S. pigment producers may be able to
moderate titanium raw material price increases, but have little power to lower prices (pass compliance costs
backwards).
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Chapter 13: Titanium Tetrachloride Production 13-29
Higher Prices
As the U.S. is a principal world producer, and foreign capacity is limited, there has been leeway to
raise prices in past years. For this reason, the price of titanium dioxide pigment has already risen significantly
over the last several years. There is a limit to price elasticity, however, particularly in the paper industry,
where competitive materials replace (or limit) the use of titanium dioxide in some applications. The paper
industry is striving to reduce consumption of titanium dioxide because of the high price levels. This has been
done, particularly in plants using alkaline paper making, by increasing calcium carbonate use as a titanium
dioxide extender. Although more difficult to replace in paint applications, a reduction and rationalization is
a possibility if prices continue to rise.
Additional capacity worldwide will also tend to limit price increases beyond 1990. The U.S. itself
produces a limited amount of raw materials to supply internal titanium dioxide requirements, and these would
not be economic for export on the world market, as they simply are partial feedstocks for integrated producers.
Evaluation of Cost/Economic Impacts
EPA estimates that three and possibly a forth of the nine facilities domestically producing titanium
tetrachloride would face significant impacts under full Subtitle C regulation. Costs and impacts under the
nearly identical Subtitle C-Minus and D-Plus scenarios are not expected to significantly affect any facilities;
only one facility, Timet/Henderson, is expected to have costs higher than one percent of value of shipments
or value added.
In terms of distributing costs, it seems likely that some of the costs that would be incurred under these
scenarios might be passed on in the form of higher prices. If, however, only three or four facilities are affected
out of a total of nine (or a total of 11 or 12 facilities that may be operating during the next two years)
increasing prices will be less likely. Also, because prices have already increased during the past few years, and
because these higher prices are reducing demand for titanium dioxide (the primary product from processing
the titanium tetrachloride), the industry may not be able to raise prices enough to fully recover compliance
costs. In addition, within several years, additional domestic capacity is expected to become operational making
increases in prices in order to pass on compliance costs very difficult
Given the moderate nature of the prospective cost impacts of modified Subtitle C and Subtitle D
regulation, and the healthy and globally competitive position of domestic titanium tetrachloride producers,
EPA does not believe that potential regulatory compliance costs under the RCRA Subtitle C-Minus scenario
would impose significant economic impacts upon affected facilities. Although these costs would not be shared
among all domestic producers (affected facilities account for approximately 26 percent of domestic capacity),
and therefore, affected facilities might be put at a competitive disadvantage with respect to other domestic
producers, the Agency does not believe that the long-term profitability and continued operation of these plants
would be threatened by a decision to regulate chloride process waste solids under modified Subtitle C
standards. In addition, adequately protective standards and their costs under a modified Subtitle C program
are in many ways identical to the probable standards and costs that would result from Subtitle D regulation,
suggesting that generators of this waste may face costs from modifying their existing waste management
practices regardless of whether this waste remains within the Mining Waste Exclusion.
13.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For the
special waste generated by facilities in this commodity sector (chloride process waste solids), these categories
address the following three major topics: (1) the potential and documented danger to human health and the
environment; (2) the need for and desirability of additional regulation; and (3) the costs and impacts of
potential Subtitle C regulation.
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13-30 Chapter 13: Titanium Tetrachlorlde Production
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of the chloride process waste solids is relatively high (at some facilities) compared
to the other mineral processing wastes studied in this report. Based on EP leach test results, 3 out of 16
samples (from 3 of 7 facilities tested) contain chromium concentrations in excess of the EP toxicity regulatory
levels; lead was also measured in EP leachate in concentrations that exceed the regulatory level in 1 out of
16 samples (from 1 of 6 facilities tested). Chromium and lead concentrations measured in SPLP (EPA
Method 1312) leachate also exceed the EP toxicity regulatory levels at one facility for which comparable SPLP
test data are available. Moreover, the waste solids contain 12 constituents in concentrations that exceed the
risk screening criteria used in this by more than a factor of 10. Nine of these constituents are metals that are
expected to be relatively mobile if released to ground water, considering the acidic nature of the leachate. The
waste solids may also contain uranium-238, thorium-232, and their decay products in concentrations that could
pose an unacceptably high radiation risk if the solids were allowed to be used in an unrestricted manner. All
of these factors lead EPA to conclude that the waste solids could present a significant hazard if mismanaged.
Based on an examination of existing release/exposure conditions at the nine active .titanium
tetrachloride facilities, EPA further concludes that management of the waste solids could allow contaminants
to migrate into the environment, but that the potential for significant exposures to this contamination is
currently low. For example, half of the facilities have a moderate to high potential for contaminants to
migrate into ground water because they have large unlined surface impoundments and/or are underlain by
shallow ground water, most facilities are adjacent to creeks or rivers into which contaminants might migrate,
and the solids are susceptible to wind erosion when managed in uncovered piles or landfills. Based on
predictive modeling for the "most sensitive" sites, EPA estimates that the concentrations of arsenic in ground
water at the property boundary could pose a lifetime cancer risk as high as 3x10"*. In terms of current
exposures, however, nobody presently drinks the ground water at this location, and the predicted arsenic
concentration at the nearest existing residence that could have a drinking water well would pose a cancer risk
of less than 10'10. The Agency's predicted concentrations of contaminants in surface waters near the sites are
well below human health and environmental protection benchmarks. Similarly, EPAs predicted concentrations
of windblown contaminants at locations of existing residences would pose a cancer risk of no more than 2xlO"7.
Based on the lack of documented cases of damage caused by the waste solids, it appears that the
solids, as currently managed, have not caused significant human health or environmental impacts. State and
EPA Regional files were reviewed and regulatory staff were interviewed in an effort to document the
performance of waste management practices for chloride process waste solids at the nine active titanium
facilities as well as two inactive facilities. Through these case studies, EPA found no documented
environmental damages attributable to management of chloride process waste solids from titanium
tetrachloride production at any of these facilities. Some cases of documented damage attributable to other
wastes were identified at some titanium facilities, however, and it is possible, though not demonstrated, that
waste solids have contributed to these observed damages.
Likelihood That Existing Risks/Impacts Will Continue in the Absence of
Subtitle C Regulation
At several of the active facilities, the current waste management practices and environmental
conditions may allow contaminant releases and risks in the future in the absence of more stringent regulation.
For example, only 2 of the 15 impoundments and none of the landfills or waste piles used to manage the solids
are equipped with either a synthetic liner or leachate collection system, even though usable ground water at
many sites is relatively shallow (6 meters deep or less) and separated from the base of the units by relatively
permeable earth materials. Many of the facilities are also located in humid areas with moderate to high
rainfall and ground-water recharge rates, which can lead to contaminant migration. Similarly, none of the four
facilities that manage the solids in waste piles or landfills practice any dust suppression, even though the waste
solids are susceptible to wind erosion when managed in a dry form. Therefore, contaminant migration during
the operating life of most units appears possible, and these releases could persist after closure if the units are
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Chapter 13: Titanium Tetrachloride Production 13-31
not closed properly. Considering the intrinsic hazard of the waste, significant exposures to these releases could
occur if nearby ground water is used.
The titanium tetrachloride production industry is also expected to expand in the future. The Bureau
of Mines has reported that it expects an increase in titanium tetrachloride production capacity of
approximately 600,000 metric tons by 1992 (current national production capacity is estimated to be 1.8 million
metric tons per year). This increased production capacity likely will be made up by the addition of new
facilities, for which management practices (in the absence of regulation) and environmental settings cannot
be predicted at this time. Depending on the environmental characteristics of these sites, releases and risks
could result if the waste solids are not properly managed.
The existing state regulatory programs appear to provide only limited control over the management
of the waste solids, though they are growing more stringent in some states. With the possible exception of
California, the eight states where titanium tetrachloride facilities are currently located exclude the waste solids
from hazardous waste regulations. Based on a review of the regulatory programs in four states (Delaware,
Mississippi, Ohio, and Tennessee), only Delaware appears to be regulating the waste solids extensively. The
waste solids in Ohio and Mississippi are not subject to solid waste permit requirements, and Tennessee has
focused its regulatory efforts on municipal solid waste problems rather than mining and mineral processing
wastes. Delaware, Ohio, and Tennessee, however, have all recently adopted new regulations that could be used
to address titanium waste solids and other mineral processing wastes more directly and comprehensively.
Costs and Impacts of Subtitle C Regulation
EPA has evaluated the costs and associated impacts of regulating this waste as a hazardous waste
under RCRA Subtitle C. EPAs waste characterization data indicate that chloride process waste solids may
exhibit the hazardous waste characteristic of EP toxicity at as many as four of the nine active facilities.
Therefore, the Agency's cost and impact analysis is limited in scope to these four facilities, because the
remaining five plants would not be affected by a decision to remove ihis waste from the Mining Waste
Exclusion. These four plants in combination account for approximately 26 percent of domestic titanium
tetrachloride production.
Costs of regulatory compliance exceed S3 million annually, even under the least stringent
(Subtitle D-Plus) scenario. Full Subtitle C regulation implies potentially significant economic impact at all
four facilities, while application of the more flexible Subtitle C-Minus regulatory scenario would result in
compliance costs that are approximately 75 percent lower. Costs under the Subtitle C-Minus and Subtitle D-
Plus scenarios are almost identical, because adequately protective waste management unit design and operating
standards are essentially the same under both scenarios, given the nature of the waste and the environmental
settings in which it is currently managed. EPA's economic impact analysis suggests that the operators of
potentially affected titanium tetrachloride plants could pass through a portion of any regulatory compliance
costs that they might incur to product consumers. Demand for and prices of titanium dioxide, the principal
end-product of titanium tetrachloride manufacturing, have been strong in recent years, as evidenced by the fact
that four new domestic plants are projected to be on-line by 1992. Consequently, EPA believes that regulation
of chloride process waste solids from titanium tetrachloride production under Subtitle C of RCRA would not
threaten the long-term profitability or economic viability of any of the facilities that generate this waste.
Finally, EPA is not aware of any significant recycling or utilization initiatives that would be hampered
by a change in the regulatory status of this waste. Recycling has been attempted in the past, but has not been
operationally successful. There have also been attempts to recover tantalum, columbium, and other rare earth
metals from the chloride process waste solids, but the techniques employed are at an early (bench-scale) stage
of development.
-------
Chapter 14
Primary Zinc Processing
For purposes of this report, the primary zinc processing sector consists of one facility that, as of
September 1989, was the only active zinc facility using pyrometallurgical (smelting) techniques and reported
generating a special waste from mineral processing: slag from primary zinc processing. Three additional
facilities are also primary producers of zinc. These facilities, however, use electrolytic production techniques
that do not generate any special wastes, that is, the wastes from electrolytic productions are no longer Bevill
excluded wastes.1 Therefore, the primary electrolytic processors' operations are not discussed in this report.
The information included in this section is discussed in additional detail in a technical background document
in the supporting public docket for this report.
14.1 Industry Overview
Zinc metal is used in many applications, primarily in the construction, transportation, machinery,
electrical, and chemical industries. The predominant use is for galvanizing and electrogalvanizing; other
applications include manufacture of brass, bronze, zinc-based alloys, and rolled zinc. Zinc oxide is the most
widely used compound of zinc, and is used both for its light-sensitive characteristics and as a starting material
in the production of other zinc chemicals.2
The sole pyrometallurgical zinc production facility in the U.S. is located in Monaca, Pennsylvania.
The facility is operated by Zinc Corporation of America (ZCA); that company is in turn owned by Horsehead
Industries, headquartered in New York City. The facility initiated operations in 1936 and was modernized in
1980, at which time four electrothermic furnaces began operation. The facility's 1988 annual capacity, based
on a 366 day year, was 101300 metric tons of zinc. In 1988, the annual capacity utilization rate was 98.5
percent, based on total 1988 reported production of 99,800 metric tons of zinc.3
In 1989, zinc consumption increased in the Western World (i.e., the world market not including
Eastern European countries) for the seventh consecutive year. A major force in zinc's performance has been
the strong demand from the automobile industry for galvanized sheet metal. Galvanizing accounted for 45
percent of zinc consumption in 1989, followed by brass manufacturing at 20 percent and die casting at 15
percent. While zinc demand is likely to stabilize in 1990, due to a slowdown in North America, it is expected
to rise again in 1991.4
Because of the steadily increasing demand for galvanized sheet metal - the healthy growth trend for
zinc witnessed in the 1980's is likely to continue into the 1990's. In 1989, U.S. production of mined zinc rose
by 17 percent, to 300,000 metric tons; this marked the third straight year that production rose, owing to the
startup of six new and reopened mines.5 By 1991, U.S. mine production of zinc could double that of 1989
due, primarily, to the huge Red Dog, Alaska mine, which opened in November 1989.6 However, increased
1 In addition to the primary facilities, as many as ten secondary facilities may be operating; the operations conducted at these facilities,
however, fall outside the definition of primary mineral processing and, accordingly, do not generate special mineral processing wastes.
2 Bureau of Mines, 1985. Mineral Facts and Problems. 1985 Ed., p. 929.
3 Zinc Corporation of America, 1989(a). Response to "National Survey of Solid Wastes from Mineral Processing Facilities", 1989.
4 Edward M. Yates, "Zinc Prices Top Out in 1989," EAMJ. March 1990, p. 20-22.
5 Ibid.
* James H. Jolly, U.S. Bureau of Mines, Mineral Commodity Summaries. 1990 Ed., p. 191.
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14-2 Chapter 14: Primary Zinc Processing
domestic zinc mining is not expected to raise U.S. metal production, because most new mine output is
scheduled for export because of a lack of zinc smelting capacity in the United States.7
While primary zinc slab production has remained relatively flat in the late 1980's (up only 1.5 percent
since 1985, from 261,000 metric tons to 265,000 metric tons), secondary zinc slab production has shown a
strong increase, up 51 percent since 1985 from 73,000 metric tons to 110,000 metric tons. Another trend
evident in the late 1980's and likely to continue in the near future is the use of electrolytic zinc smelting
techniques. During the 1980's the zinc industry has moved steadily away from pyrometallurgical smelting
operations to the more energy efficient, cost effective electrolytic smelting operations. Only one primary
pyrometallurgical zinc smelting facility - the Monaca, Pennsylvania that is described in this chapter -- is
currently operating in the United States. Any new zinc slab primary processing capacity, developed to meet
increased demand for zinc, will likely come from electrolytic facilities rather than pyroraetallurgical facilities.
However, because of its ability to process secondary materials, the Monaca facility is likely to be able to
maintain its market position for the forseeable future.
In the smelting process, zinc is vaporized from sintered calcine in retort furnaces and then condensed
and recovered (see Exhibit 14-1).8 At the Monaca facility, medium to high grade sulfide concentrates are
roasted and sintered in preparation for retorting. Significant quantities of high-grade calcine extracted from
electric air furnace (EAF) dust and other secondary materials (e.g., skimmings and drosses) that are not as
readily recoverable in electrolytic zinc plants are used to supplement the ore concentrate feed.9'10 The ore
concentrate and secondary feed values are charged along with an equal volume of coke into the top of one
of four vertical shaft electrothermic furnaces.11 Electric current, supplied from a company owned coal-fired
power plant, flows through the charge, supplying the energy required for the reduction reaction through
resistance heating. Zinc vapor from the retorts passes into distillation columns in the refinery where the
purified zinc vapor is collected as a liquid metal and cast into metal or processed into various products. A
solid residue remains behind in the retort furnace; this is the zinc slag that is the special waste.
14.2 Waste Characteristics, Generation, and Current Management Practices12
The zinc slag that is removed from the furnaces is a rock-like solid material (pieces range in size from
three inches to a foot in diameter) composed primarily of iron, silicon, and unreacted coke. Non-confidential
waste generation rate data were reported for this material by the ZCA. The generation of furnace slag was
approximately 157,000 metric tons in 1988, thus, the 1988 waste-to-product ratio was 1.6 metric tons of slag
to each metric ton of zinc product.
At the Monaca facility, the slag from the furnace goes directly to one of two crushers while it is still
red hot. A series of crushing/separation operations are employed to separate the slag into the four material
streams shown in Exhibit 14-2,
The fines and coke are recycled to beneficiation and processing operations at the facility. On the
other hand, the processed slag is stored in slag waste piles, disposed in a flyash landfill, or sold for such uses
as road gravel or construction aggregate, while the ferrosilicon is accumulated in a stockpile until it can be
sold. The processed slag is (ranging in size from approximately 13 cm to 6.4 cm (0.5 to 2.5 inches)
accumulated in the storage piles (some of which is subsequently used as road gravel or in the flyash landfill),
7 Ibid.
8 Marks, 1978. Encyclopedia of Chemical Technology. Marks, el al., editors; Wiley Intentience, New York, NY, 1978; p. 827.
9 James H. Jolly, 1990. Personal communication, June 27, 1990.
10 Weiss, 1985. SME Mineral Processine Handbook. Weiss, N.L, editor; Society of Mining Engineers, NY, NY, 1985; pp. 15:11-12.
11 Zinc Corporation of America, 1989(b). Public comments from Zinc Corporation of America addressing the 1989 proposed
Reinterpretation of the Mining Waste Exclusion (Docket No. - MWRP00073); May 30,1989; Appendix A.
12 All responses, unless noted are from the response of Zinc Corporation of America to EPA's "National Survey of Solid Wastes from
Mineral Processing Facilities", conducted in 1989.
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Chapter 14: Primary Zinc Processing 14-3
Exhibit 14-1
Pyrometallurgical Primary Zinc Processing
PROCESS
-> Zinc Metol
Ore
Concentrater
k
Dryer
.
'
Zinc Oxide
SPECIAL WASTE
MANAGEMENT
Zinc Fines
Zinc Slag
Reclaimed Coke
Ferrosilicon
Slag Treatment
Legend
Production Operation
C -- J
Special Waste
\— /
Processed
Slag
Waste Management Unit
while the ferrosilicon pile contains particles that are typically about 0.64 cm in size.
Of the 157,000 metric tons of total raw zinc slag generated at the zinc processing facility in 1988,
28,000 metric tons and 17,000 metric tons were separated out as processed slag and ferrosilicon, respectively.
The ferrosilicon is accumulated in a pile that is approximately 7 meters high and has a basal area of 8,000
square meters (2 acres). The processed slag pile (in several adjacent piles) covers an area of about 1.2 hectares
and is roughly 7 meters in height. In addition, slag has been placed in a layer at the bottom of the facility's
flyash landfill that is approximately 0.3 meters (1 foot) deep and covers an area of about 8 hectares. Slag has
also been used as gravel on parking lots and other areas of the plant site. As of 1988, the quantities of waste
accumulated in the ferrosilicon pile, processed slag pile, and the landfill were roughly 48,000, 63,500, and
45,400 metric tons, respectively.
Using available data on the composition of zinc slag, processed slag, and ferrosilicon, EPA evaluated
whether any of these materials exhibit any of the four hazardous waste characteristics: corrosivity, reactivity,
ignitability, and extraction procedure (EP) toxicity. Based on available information and professional judgment,
EPA does not believe that any of the three materials are corrosive, reactive, or ignitable; however, samples
of all three frequently exhibit the characteristic of EP toxicity based on the lead content, as shown below.
• Generated Slag. EP leach test concentrations of all eight inorganic constituents with
EP toxicity regulatory levels are available for one sample of zinc slag from the Monaca
facility. Of these constituents, only lead was found to exceed the EP toxicity regulatory
level, by a factor of 12. The zinc slag sample that failed the EP toxic level was also
analyzed using the SPLP leach test; this test indicates that the lead concentration was
three orders of magnitude below the EP toxic level.
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14-4 Chapter 14: Primary Zinc Processing
Exhibit 14-2
Primary Management of Zinc Slag
Residual Stream
Zinc fines
Reclaimed Coke
Processed Slag
Ferro*ilicon
Quantity (mt/yr)
79,000
33,000
28,000
17,000
Residual Management
Returned to Sinter Plant
Recycled to Retort Furnace
Disposed
Stockpiled
Processed Slag. EP leach test concentrations of all eight inorganic constituents with EP
toxicity regulatory levels are available for 36 samples of processed slag from the Monaca
facility. Of these constituents, only lead was found to exhibit the characteristic of EP
toxicity for lead in 25 samples by as much as a factor of 12.8. One of the processed zinc
slag samples that exhibited the characteristic of EP toxicity was also analyzed using the
SPLP leach test; these data indicate that the concentration of lead measure exhibited
the characteristic of using the SPLP leach test was roughly three orders of magnitude
below the EP toxic regulatory level.
Ferrosilicon. EP leach test concentrations of all eight inorganic constituents with EP
toxicity regulatory levels are available for one sample of ferrosilicon from the Monaca
facility. The only constituent detected in the ferrosilicon in a concentration that exceeds
the EP level was lead (it exceeded the EP level by a factor of almost 10). The
ferrosilicon sample that failed the EP toxic level was also analyzed using the SPLP leach
test; the resulting concentration of lead was three orders of magnitude below the EP
toxic levels.
14.3 Potential and Documented Danger to Human Health and the Environment
This section addresses two of the study factors required by §8002(p) of RCRA: (1) potential danger
(i.e., risk) to human health and the environment; and (2) documented cases in which danger to human health
or the environment has been proven. Overall conclusions about the hazards associated with zinc slag are
provided after these two study factors are discussed.
14.3.1 Risks Associated With Processed Zinc Slag and Ferrosilicon
Because two of the four material streams arising from zinc slag processing are recycled directly to the
production process without any potential contact with the environment, EPAs risk analysis of primary zinc
slag is limited to an examination of the processed slag and the ferrosilicon. Any potential danger to human
health and the environment from these two wastes is a function primarily of the composition of these
materials, the management practices that are applied to them, and the environmental setting of the facility
where the processed zinc slag and ferrosilicon are generated and managed. These factors are discussed
separately below for each material, followed by EPAs risk modeling results.
-------
Chapter 14: Primary Zinc Processing 14-5
Constituents of Potential Concern in Processed Zinc Slag
EPA identified chemical constituents in the processed zinc slag (as managed) that may pose a risk
by collecting data on the composition of slag from the Zinc Corporation of America facility in Monaca, and
evaluating the intrinsic hazard of the chemical constituents present in the slag.
Data on Processed Zinc Slag Composition
EPAs characterization of processed zinc slag and its leachate is based on data from two sources: (1)
a 1989 sampling and analysis effort by EPAs Office of Solid Waste (OSW); and (2) industry responses to a
RCRA §3007 request in 1989. (The §3007 data provided only results of EP leach test analyses.) These data
provide information on the concentrations of 19 metals and chloride in total solids and leach test analyses.
Concentrations of most constituents from leach test analyses of the processed zinc slag generally are consistent
across the data sources and types of leach tests (i.e., EP and SPLP). EP leach test concentrations of zinc,
however, were approximately four orders of magnitude higher than zinc concentrations in SPLP leach test
analyses.
Process for Identifying Constituents of Potential Concern
As discussed in detail in Section 2.2.2, the Agency evaluated the zinc slag data to determine if the slag
or slag leachate contain any chemical constituents that could pose an intrinsic hazard, and to narrow the focus
of the risk assessment. The Agency performed this evaluation by first comparing constituent concentrations
to conservative screening criteria and then by evaluating the environmental persistence and mobility of any
constituents present in concentrations above the criteria. These screening criteria are conservative because
they were developed using assumed scenarios that are likely to overestimate the extent to which the zinc slag
constituents are released to the environment and migrate to possible exposure points. As a result, this process
identifies and eliminates from further consideration those constituents that clearly do not pose a risk.
The Agency used three categories of screening criteria that reflect the potential for hazards to human
health, aquatic ecosystems, and water resources (see Exhibit 2-3). Given the conservative nature (i.e., overly
protective) nature of these screening criteria, contaminant concentrations in excess of the criteria should not,
in isolation, be interpreted as proof of hazard. Instead, exceedances of the criteria indicate the need to
evaluate the potential hazards of the slag in greater detail.
Identified Constituents of Potential Concern
Exhibits 14-3 and 14-4 present the results of the comparisons for zinc slag solid and leach test
analyses, respectively, to the screening criteria described above. These exhibits list all constituents for which
sample concentrations exceed a screening criterion.
Of the 20 constituents analyzed in the zinc slag solids, only chromium, lead, nickel, and selenium are
present at concentrations exceeding the screening criteria (see Exhibit 14-3). These four metals were detected
in all samples analyzed, but based on the frequency and magnitude of their concentrations exceeding the
screening criteria, chromium and lead are of greater potential concern. Chromium exceeded the inhalation
criterion by as much as a factor of 13 and lead exceeded the ingestion criterion by a factor of 6; nickel and
selenium exceeded the criteria by a factor of roughly 1.2, All of these constituents are persistent in the
environment (i.e., they do not degrade).
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14-6 Chapter 14: Primary Zinc Processing
Exhibit 14-3
Potential Constituents of Concern in Zinc Slag Solids(a)
Potential
Constituent*
of Concern
Chromium
Lead
Nickel
Selenium
Number of Times
Constituent Dectected/
Number of Analyses for
Constituent
2/2
2/2
2/2
2/2
Human Health
Screening Criteria0**
Inhalation*
Ingestion
Inhalation*
Inhalation
Number of Analyses
Exceeding Criteria/
Number of Analyses for
Constituent
2/2
1 12
1/2
1 12
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10"* lifetime cancer
risk; others are based on noncancer effects.
These exceedances of the screening criteria indicate the potential for two types of adverse effects, as
follows:
• Lead concentrations in processed zinc slag may cause adverse health effects if a small
quantity of zinc slag or soil contaminated with the slag is inadvertently ingested on a
routine basis (e.g., if children playing on abandoned waste piles or driveways made from
slag were to inadvertently ingest the slag).
• Chromium, and to a lesser extent, nickel and selenium concentrations exceed the health-
based screening criteria for inhalation. Thus, chromium and nickel could pose a cancer
risk (i.e., greater than IxlO'5) while selenium could cause adverse noncancer effects if
slag dust is blown into the air and is inhaled in a concentration that equals or exceeds
the National Ambient Air Quality Standard for paniculate matter. However, as
discussed in a following section, the Agency does not expect such large releases and
exposures because the vast majority of the waste slag exists as particles too large to be
suspended, transported, or respired. It is likely that only a very small fraction of the
slag will be weathered and aged (or crushed) into smaller panicles that can be
suspended in air and cause airborne releases and related impacts.
Based on a comparison of leach test concentrations of 20 constituents to surface and ground-water
pathway screening criteria (see Exhibit 14-4), nine constituents (lead, manganese, zinc, copper, cadmium,
nickel, arsenic, selenium, and iron) are present in concentrations that occasionally exceed the criteria. Of these
constituents, lead, manganese, zinc, and copper appear to present the greater potential hazard because their
concentrations in all samples analyzed exceed at least one screening criterion. Only lead, manganese, zinc, and
arsenic exceeded the screening criteria by a factor of 10 or more, and only lead was detected in concentrations
above the EP toxicity regulatory level. All of these constituents are inorganics that do not degrade in the
environment.
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Chapter 14: Primary Zinc Processing 14-7
Exhibit 14-4
Potential Constituents of Concern in Zinc Slag Leachate^
Potential
Constituent*
of Concern
Lead
Manganese
Zinc
Copper
Cadmium
Nickel
Arsenic
Selenium
Iron
Number of Times
Constituent Dectected/
Number of Analyses for
Constituent
35/35
2/2
2/2
2/2
29/34
2/2
2/26
1 /24
2/2
Screening Criteria"4
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Human Health
Resource Damage
Aquatic Ecological
Aquatic Ecological
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Human Health*
Resource Damage
Resource Damage
Number of Analyses
Exceeding Criteria/
Number of Analyses for
Constituent
34/35
35/35
34/35
2/2
2/2
2/2
2/2
2/2
1/34
4/34
4/34
1 12
2/2
2/26
1 /24
1/2
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. The constituent
concentrations used for this analysis are based on EP leach test results.
(b) Human health screening criteria are based on exposure via incidental ingestion and inhalation. Human health effects
include cancer risk and noncancer health effects. Screening criteria noted with an '*' are based on a 1x10"5 lifetime cancer
risk; others are based on noncancer effects.
These exceedances of the screening criteria indicate the potential for the following types of impacts
under the following conditions:
• If the slag leachate is released and diluted by only a factor of 10 during migration to a
drinking water supply, concentrations of lead, zinc, cadmium, and arsenic in zinc could
cause adverse health effects from the long-term chronic ingestion of untreated drinking
water. The diluted concentration of arsenic could pose a cancer risk of greater than
IxlO"5 from drinking water exposures.
• Concentrations of lead, zinc, copper, cadmium, and nickel in zinc slag leachate could
threaten aquatic organisms if the leachate enters surface water and is diluted by a factor
of 100.
• If released to ground water or surface water and diluted by a factor of 10 or less during
migration, lead, manganese, zinc, cadmium, nickel, selenium, and iron concentrations
in zinc slag leachate potentially could exceed drinking water maximum contaminant
levels or irrigation guidelines.
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14-8 Chapter 14: Primary Zinc Processing
These exceedances of the screening criteria, by themselves, do not demonstrate that zinc slag poses
a significant risk, but rather indicate that the slag could pose a risk under a very conservative, hypothetical set
of release, transport, and exposure conditions. To determine the potential for the slag to cause significant
impacts, EPA analyzed the actual conditions that exist at the facility that generates and manages the waste (see
the following section on release, transport, and exposure potential).
Constituents of Potential Concern in Ferrosilicon
Using the same process summarized for processed slag, EPA identified chemical constituents in the
ferrosilicon that may pose a risk by collecting data on the composition of this material from the Monaca
facility, and evaluating the intrinsic hazard of the chemical constituents present in the ferrosilicon.
Data on Ferrosilicon Composition
EPAs characterization of ferrosilicon and its leachate is based on data from OSW's 1989 sampling
and analysis effort. These data provide the concentrations of 18 metals in total solids and leach test (both EP
and SPLP) analyses, and represent samples of the ferrosilicon as it is managed at the Monaca plant.
Concentrations of most constituents from leach test analyses of the ferrosilicon generally are
consistent across the two types of leach tests. EP leach test concentrations of zinc and lead, however, were
almost three orders of magnitude higher than the concentrations of these metals in SPLP leach test analyses.
Identified Constituents of Potential Concern
As in the zinc slag, only chromium, lead, nickel, and selenium are present in the ferrosilicon at
concentrations exceeding the screening criteria. Although the concentrations of all four of these constituents
exceed screening criteria in all samples analyzed, lead and chromium exceed the criteria by the widest margin
(lead exceeds by a factor of 20 and chromium exceeds by a factor of 9; nickel and selenium exceed by a factor
of 4 or less). Just like the slag, lead concentrations in ferrosilicon exceed the screening criterion for ingestion,
while chromium, and to a lesser extent, nickel and selenium concentrations exceed the health-based screening
criteria for inhalation.
Based on a comparison of leach test concentrations for the 18 constituents to the surface and
ground-water pathways screening criteria (see Exhibit 14-5), seven metals (lead, manganese, copper, nickel,
zinc, selenium, and iron) were detected at levels above the screening criteria. Concentrations of these metals
in all samples analyzed exceed at least one screening criterion. However, lead, manganese, and copper exceed
the screening criteria by the widest margins. Lead exceeds by as much as a factor of 970, and copper and
manganese exceed by factors of 24 and 30, respectively. The concentrations of the other constituents exceed
the screening criteria by less than a factor of 10. Only lead was detected in a concentration that exceeds the
EP toxicity regulatory level.
These exceedances indicate the potential for three types of impacts, as follows:
• Concentrations of lead and nickel in ferrosilicon leachate could cause adverse health
effects from the long-term chronic ingestion of untreated drinking water if the leachate
migrates to drinking water supplies with only a tenfold dilution. The diluted
concentration of arsenic in slag leachate could pose a cancer risk of greater than IxlO'5
from drinking water exposures.
• Concentrations of lead, copper, nickel, and zinc in leachate from the ferrosilicon could
present a threat to aquatic organisms if the leachate enters a surface water and is
diluted by a factor of 100.
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Chapter 14: Primary Zinc Processing 14-9
Exhibit 14-5
Potential Constituents of Concern in Ferrosilicon Leachate^
Potential
Constituent*
of Concern
Lead
Manganese
Copper
Nickel
Zinc
Selenium
Iron
Number of Times
Constituent Dectected/
Number of Analyses for
Constituent
1/1
1 /1
1/1
1/1
1/t
1 /1
1/1
Screening Criteria
Human Health
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Human Hearth
Resource Damage
Aquatic Ecological
Resource Damage
Aquatic Ecological
Resource Damage
Resource Damage
Number of Analyses
Exceeding Criteria/
Number of Analyses for
Constituent
1 /1
1 /t
1 M
1 M
1/t
1 /1
1 / 1
1 /1
1/1
1/1
1/1
1/1
(a) Constituents listed in this table are present in at least one sample from at least one facility at a concentration that exceeds
a relevant screening criterion. The conservative screening criteria used in this analysis are listed in Exhibit 2-3.
Constituents that were not detected in a given sample were assumed not to be present in the sample. The constituent
concentrations used for this analysis are based on EP leach test results.
• Lead, manganese, nickel, zinc, selenium, and iron may be present in ferrosilicon leachate
at concentrations that, if released to ground or surface water and diluted by a factor of
10 or less, potentially could exceed drinking water maximum contaminant levels and
irrigation guidelines.
As explained for zinc slag, these exceedances do not demonstrate that ferrosilicon poses human health
or environmental risks, but rather indicate that the waste could pose risks under a very conservative,
hypothetical set of exposure conditions. Ib examine the potential hazards of ferrosilicon in greater detail,
EPA proceeded to the next step of the risk assessment to evaluate the actual release, transport, and exposure
conditions at the Monaca facility.
Release, Transport, and Exposure Potential
This analysis considers the baseline hazards of processed slag and ferrosilicon as they were managed
at the Monaca plant in 1988:
• Processed zinc slag is stored in a waste pile and is used as drainage material in a flyash
landfill. The slag pile covers an area of 1.2 hectares (3 acres) and is roughly 7 meters
(23 feet) in height. The processed slag in the flyash landfill is approximately 0.3 meters
deep and covers an area of 8 hectares.
• Ferrosilicon is accumulated in a pile that is approximately 7 meters (23 feet) high and
has a basal area of 0.8 hectares (2 acres).
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14-10 Chapter 1.4: Primary Zinc Processing
For this analysis, the Agency did not assess the hazards of off-site disposal or use of the wastes
because neither waste is disposed off-site. Although a portion of the slag is sold for off-site use as road gravel
or construction aggregate and there are plans to sell the ferrosilicon for use off-site as a source of iron,
insufficient information is available to support a detailed analysis of the risks posed by these off-site
operations. Existing and potential off-site management practices of these wastes, however, are discussed
generally in Section 14.5. In addition, the following analysis does not consider the hazards associated with
variations in waste management practices or potentially exposed populations in the future because of a lack
of adequate information on which to base projections of future conditions.
Ground-Water Release, Transport, and Exposure Potential
The EPA and industry test data discussed above show that several constituents are capable of leaching
from the processed zinc slag and ferrosilicon in concentrations that exceed the screening criteria. However,
considering the existing waste management practices and neutral pH of the leachate, the only slag
contaminants that are expected to be mobile in ground water if released are cadmium, arsenic, and selenium.
The single ferrosilicon contaminant that is expected to be mobile in ground water is selenium.
The potential for these contaminants to be released to a useable aquifer and transported to exposure
points is determined by a number of site-specific factors, such as the presence of engineered ground-water
protection controls, depth to ground water, precipitation and net recharge, presence of intervening confining
layers/aquifers, and the distance to down-gradient drinking water wells.
Because there are no liquids associated with the processed zinc slag as it exists in the waste pile or
the landfill, there is no hydraulic head to drive the flow of contaminants from these management units.
Similarly, no liquids are associated with ferrosilicon in its waste pile. Therefore, the potential for contaminants
from these two wastes to leach into ground water is entirely dependent on the extent to which precipitation
can infiltrate through the slag and into the ground. The annual precipitation at the location of this facility
is relatively high (91 cm/year). Much of this precipitation is expected to infiltrate into ground water because
the subsurface is generally quite permeable (i.e., net recharge at this location is a relatively high 25 cm/year).
Thus, in the absence of engineered ground-water protection controls, leachate originating from the waste
management units could seep into the ground. Useable ground water at the site, however, is relatively deep,
approximately 24 meters beneath the units, and therefore somewhat protected from contamination.
The processed zinc slag pile and the ferrosilicon pile are not equipped with any engineered controls
such as liners or leachate-collection systems to limit releases to ground water. However, the landfill in which
zinc slag is used as a drainage material is underlain by in-situ clay and is equipped with a leachate collection
system. Given these management controls and the hydrogeological characteristics of the area, the potential
for processed zinc slag and ferrosilicon leachate to migrate from the waste piles to ground water is moderate
to high. Slag leachate could also migrate from the landfill to ground water if the in-situ clay layer beneath
the unit is discontinuous or the leachate collection system were to fail. However, monitoring at the facility
indicates that drinking water standards have not been exceeded in the ground water. In addition, the
concentration of some contaminants, most notably lead and zinc, in actual leachate is likely to be less than
in the EP leachate because current disposal practices do not expose the wastes to sources of organic acids.
The aquifer beneath the facility currently supplies both drinking and commercial/industrial water. A
drinking water well serving the Beaver County Home and Hospital is located very close to the facility
(approximately 120 meters); however, this well appears to withdraw water from the deep useable aquifer and
is unlikely to be significantly affected by the waste leachate. Thus, the potential for exposure is likely to be
minimal. The Agency has no data on the presence of shallower ground water at this site, but considering the
close proximity of the facility to the Ohio River, shallow ground water probably does exist. Any shallow
ground water, however, is likely to discharge directly into the river and does not appear "useable."
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Chapter 14: Primary Zinc Processing 14-11
Surface Water Release, Transport, and Exposure Potential
In theory, constituents of potential concern from processed zinc slag in the landfill and waste pile,
as well as from the ferrosilicon in the waste pile, could enter surface waters by migration of leachate from the
waste management units through ground water that discharges to surface water, or direct overland
(stormwater) run-off of dissolved or suspended materials. As discussed above, the following constituents leach
from the processed zinc slag and ferrosilicon under the conditions of the EP-toxicity test at levels above the
screening criteria and are mobile in ground water: cadmium, arsenic, and selenium. Other constituents in the
processed zinc slag and the ferrosilicon theoretically could pose a threat if they migrated into surface waters
in the form of suspended particles.
The physical form of the processed zinc slag and the ferrosilicon should help limit the overland
erosion of solids from the waste piles. The slag accumulated in the pile consists of particles of four sizes,
typically ranging in size from approximately 0.2 to 7.5 cm while ferrosilicon accumulated in the waste pile
consists of particles that are approximately 0.64 cm in size. Because only particles that are 0.1 mm or less in
size tend to be appreciably credible,13 only a very small fraction of the zinc slag or ferrosilicon solids are
likely to erode to any significant extent. The potential for stormwater run-off to carry both the erodible
fraction of zinc slag and ferrosilicon and dissolved constituents from these wastes is high because the
precipitation in this area is high (91 cm/year), the slope of the land is relatively steep (6 to 12 percent), and
the waste pile lacks stormwater run-on/run-off controls to prevent surface erosion. Such routine releases are
of less concern at the landfill because it is equipped with stormwater run-on/run-off controls (and because the
slag is located in the subsurface drainage layer of this unit). Overland run-off could migrate to the Ohio River
located a short distance away (60 meters) from the facility. Episodic overland releases to the river could also
occur in a flood event because the facility is located in the 100-year floodplain. The moderate to high
potential for release to ground water (as discussed above) could also release constituents of the two wastes
to the river via discharge of contaminated ground water.
Although migration from the two waste piles and the landfill to the Ohio River are likely, any
contaminants reaching the river would be diluted rapidly due to its very large flow (approximately 23,000 mgd).
Therefore, migration of contaminants to the river could pose a moderate, but not high, risk to aquatic
organisms and could moderately restrict possible future uses of the river (e.g., for drinking water supply). It
should be noted that as far as the Agency knows, there are currently no intakes for drinking water or other
consumptive uses of this river for at least 24 km (15 miles) downstream of the facility.
Air Release, Transport, and Exposure Potential
Because all of the constituents of potential concern are nonvolatile, zinc slag and ferrosilicon
contaminants can only be released to air in the form of dust particles. The particles can be either blown into
the air by wind or suspended in air by waste dumping and crushing operations. Factors that affect the
potential for such airborne releases include the particle size of the slag and ferrosilicon, the height and
exposed surface area of the waste piles, the number of days with precipitation that can suppress dust, the use
of dust suppression controls, wind speeds, and the proximity of receptors to the Monaca facility. If airborne
releases were to occur, chromium, nickel, and selenium in the zinc slag and ferrosilicon dust could pose a risk
through the inhalation pathway.
In general, particles that are <. 100 micrometers (/tm) in diameter are wind suspendable and
transportable. Within this range, however, only particles that are <. 30 /an in diameter can be transported
for considerable distances downwind, and only particles that are <. 10 pm in diameter are respirable. As
mentioned previously, the smallest zinc slag particles are approximately 2 nun in diameter. The ferrosilicon
particles are mostly approximately 6.4 cm in size, and furthermore, they are relatively heavy due to their high
iron content. Therefore, the vast majority of the processed slag and ferrosilicon should not be suspendable,
13 As indicated by the soil credibility factor of the USDA's universal soil loss equation.
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14-12 Chapter 14: Primary Zinc Processing
transportable, or respirable. It is likely that only a very small fraction of the slag and the ferrosilicon will be
weathered and aged (or crushed) into smaller particles that can be suspended in air and cause airborne
exposure and related impacts.
At Monaca, airborne releases from processed zinc slag in the landfill are not of concern because it
is used as drainage material at the bottom of the unit. The processed zinc slag pile at this facility is relatively
small (7 meters high and covers 1.2 hectares), as is the ferrosilicon pile (7 meters high and covers 0.3 hectares).
Neither pile is covered with either vegetation or a synthetic material. Although the facility does not use any
dust suppression controls, such as sprinkling water on the piles, the number of days with rain that may
suppress dust is relatively large (119 days/yr). As a result, the surface of the two waste piles may be moist for
almost a third of the time. While the Agency assumes that there are short term gusts of stronger winds,
average wind speeds at Monaca range from 2.7 to 4.6 m/s, which are strong enough to produce wind erosion
of any fine particles that may exist on the surface of the waste piles. Based on these factors, the potential for
dusting is low at both waste piles. However, if particles are released from these waste management units, the
potential for exposure is high because of the short distance to the nearest residence (90 meters), the relatively
short distances to residences (180 meters to 670 meters) in directions with maximum wind frequency and wind
speed, and the relatively large population within 1.6 km (958 people) and 8 km (approximately 52,000 people).
Proximity to Sensitive Environments
The Zinc Corporation of America facility is located in a 100-year floodplain, which indicates that
large, episodic releases of contaminants in zinc slag and/or ferrosilicon could occur during large flood events.
The dilution capacity of the Ohio River would be very high during these events, but a large washout could
introduce a heavy load of zinc slag and ferrosilicon which could act as a source of contaminants for years to
come.
Risk Modeling
Based on the preceding analysis of the intrinsic hazard of zinc slag wastes and the potential for the
waste contaminants to be released into the environment, EPA ranked processed zinc slag and ferrosilicon as
having a relatively high potential to pose a hazard to human health and the environment (compared to the
other mineral processing wastes studied in this report). Therefore, the Agency used the model "Multimedia
Soils" (MMSOILS) to estimate the ground-water, surface water, and air risks caused by the management of
slag and ferrosilicon at the facility in Monaca, PA
Ground-Water Risks
Using site-specific data with respect to contaminant concentrations, waste quantities, existing
management practices, and hydrogeologic characteristics, EPA modeled potential releases to ground water
from the processed slag and ferrosilicon piles at the Monaca facility. EPA considered in this analysis the
potential releases of arsenic, cadmium, and selenium through the ground-water pathway based on the
preceding analysis of processed slag and ferrosilicon leachate. In addition, the Agency modeled the risks
caused by potential releases of lead to ground water, because lead concentrations measured in EP leach tests
of both the slag and ferrosilicon exceeded the EP toxicity criterion.
The Agency's ground-water modeling results indicate that all four of these contaminants are likely
to remain bound up in the unsaturated zone well beyond the modeling time frame considered (200 years).
Once released from the base of the piles, EPA predicted that it would take arsenic, cadmium, and selenium
340 to 440 years to migrate through the unsaturated zone to the water table. EPA estimated that it would
take over 10,000 years for any lead released from the piles to migrate to the water table. Therefore, the
predicted risks associated with the release of these contaminants to the subsurface are effectively zero within
the 200-year modeling horizon.
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Chapter 14: Primary Zinc Processing 14-13
Surface Water Risks
Tb evaluate surface water risks, EPA estimated the concentrations of processed slag and ferrosilicon
contaminants in the nearby Ohio River (located about 60 meters from the facility) after the contaminants have
been fully mixed in the river's flow. EPA considered in this analysis the annual loading of contaminants to
the river via ground-water seepage and erosion of small particles from the slag and ferrosilicon piles. The
Agency predicted the surface water concentrations of the following constituents: arsenic, cadmium, copper,
iron, lead, manganese, nickel, selenium, and zinc. For each constituent, the Agency compared the predicted
concentrations to EPA-approved benchmarks for human health protection, drinking water maximum
contaminant levels (MCLs), freshwater ambient water quality criteria (AWQC) for chronic exposures, and
National Academy of Sciences recommended guidelines for irrigation and livestock waters.
Based on the Agency's modeling results, it appears that the very large average flow of the Ohio River
near the Monaca site (23,000 mgd) is able to effectively assimilate chronic releases of contaminants from the
processed zinc slag and ferrosilicon piles. ERA'S predicted concentrations of each contaminant caused by
releases from the slag and ferrosilicon were at least two orders of magnitude below the various criteria. This
is true for predicted concentrations caused by releases from each waste independently, as well as total
contaminant concentrations in the river resulting from aggregate releases from the two wastes. The predicted
concentrations of arsenic, the only carcinogen modeled would pose a lifetime cancer risk of less than 2xlO'9
(i.e., the chance of getting cancer would be less than two in one billion if the water was ingested over a 70-year
lifetime). In every case, the contaminants were predicted to migrate to the Ohio River by run-off alone, not
by seepage through ground water that discharges to the river.
Of the constituents that were modeled, only selenium is recognized as having the potential to
biomagnify (concentrate in the tissues of organisms higher in the food chain). Even though the Agency
predicted selenium concentrations that are well below the AWQC, there is a potential for selenium to
biomagnify and cause adverse effects to wildlife at higher trophic levels. Cadmium, selenium, zinc, lead, and,
to a lesser extent, arsenic can bioaccumulate in the tissue of freshwater fish that may be ingested by humans.
However, even if an individual ingested 6.5 grams of fish14 from the contaminated water every day of the
year for 70 years, EPA estimates that cancer risks would be less than IxlO"9 and the doses of noncarcinogens
would be below adverse effect thresholds.
Air Risks
EPA predicted the release of windblown dust from the processed slag and ferrosilicon piles, and the
associated inhalation risks of the existing maximum exposed individual (located at a residence roughly 90
meters away in a south-southwest direction). EPA estimated the risks caused by windblown chromium, nickel,
and selenium, through the inhalation pathway based on the preceding analysis of the wastes' composition. In
general, the Agency's modeling approach was very conservative (i.e., tending to overpredict inhalation risks)
because it was based on the assumption that there is an unlimited reservoir of fine panicles that can be blown
into the air from the zinc slag and ferrosilicon piles. As discussed previously, processed slag and ferrosilicon
actually have limited wind erosion potential because the vast majority of the materials consists of large
particles that are not suspendable or transportable in typical winds.
Even with this conservative approach, risks caused by the inhalation of dust from processed slag and
ferrosilicon piles were predicted to be low. Specifically, at the residence of the maximum exposed individual,
EPA predicted a total lifetime cancer risk of roughly 2xlO*7 caused by the combined release of chromium and
nickel from both wastes (the estimated inhalation risks caused by each waste individually were approximately
the same, SxlO"8). Similarly, the predicted concentrations of selenium in air at the residence of the maximum
exposed individual, caused by each waste individually and the two wastes together, were more than two orders
14 This is a typical daily fish intake averaged over a year (EPA, Risk Assessment Guidance for Superfund. Volume I, Human Health
Evaluation Manual (Pan A), EPA/540A-89/002, December 1989).
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14-14 Chapter 14: Primary Zinc Processing
of magnitude below the threshold concentration that could be associated with noncancer effects (dermatitis
and gastrointestinal disturbances).
14.3.2 Damage Cases
State and EPA Regional files were reviewed in an effort to document the environmental performance
of zinc slag waste management practices at the active Monaca, PA smelter and four inactive zinc smelters.15
The inactive primary zinc smelters included facilities in Columbus, Ohio and El Paso, Texas, last operated by
ASARCO and facilities in DePue, Illinois and Palmerton, Pennsylvania operated by Zinc Corporation of
America (ZCA). The file reviews were combined with interviews with State and EPA regional regulatory staff.
Through these case studies, EPA found that documented environmental damages associated with slag
management had occurred at all three inactive smelters but not at the active facility.
ASARCO, Columbus, Ohio
The zinc smelter at Columbus, Ohio was owned by American Zinc Oxide from 1918 to 1970, at which
time ASARCO purchased the property and operated it until ceasing production in 1986.16'17 The facility
produced zinc oxide from sphalerite ore by oxidation, reduction, and back oxidation.18 Until recently, when
ASARCO began selling its slag for further zinc recovery to Horsehead Resources,19 it appears that all zinc
slag was disposed and/or stored on-site. As of 1986, about 38,000 tons of zinc slag had been stored on the site
in two primary slag piles: the northern pile, covering about 5 hectares (13 acres); and the southern pile,
covering about 15 hectares (37 acres).20'21
Run-off from the facility drains to an open ditch near Joyce and 12th Avenues, referred to as the
Joyce Ave. outfall. The receiving ditch, referred to as the American Ditch, flows about one mile through an
industrial and residential area.22-23 Until June 1989, when the American ditch was diverted to discharge
directly to Alum Creek, flow from the American ditch entered the combined sewer of the city of Columbus.24
Alum Creek, the present receiving stream, is classified as a primary contact, warm fishery, public, industrial,
and agricultural water supply.25
In 1972, the City of Columbus found that its wastewater treatment facility was receiving excessive zinc
and cadmium loadings from water originating at the ASARCO smelter site. Investigations eventually led to
15 Facilities are considered inactive for purposes of this report if they are not currently engaged in primary mineral processing.
16 City of Columbus. 1986. ASARCO Meeting. Representatives from Columbus Division of Sewerage and Drainage, Ohio EPA and
ASARCO. October 30.
17 Ohio Environmental Protection Agency. 1987. Inter-office communication from L. Korecko and C Chao through W. McCarthy,
CDO-DWPC, to R. Mehlhop, CDO-DWQMA, Re: Use Evaluation, Tories Evaluation, Heavy Metals Allocation, etc. for ASARCO in
Columbus. August 24.
18 Ohio Department of Health. 1972. Untitled document concerning the history of the site and identification and solution of pollution
problems. July 20.
19 ASARCO. 1987. Letter from R. Marcus, Senior Environmental Scientist, to W. Schneider, Ohio EPA. January 30.
M City of Columbus, O£. cit.
21 ASARCO, 0£. cit.
22 City of Columbus. 1981. Memorandum to R. C Parkinson, Director of Public Service, through D.D. Robbins, Superintendent, from
G. W. Newell, Manager of Surveillance, Re American Ditch, ASARCO Pollution Problems. October 15.
23 Ohio Environmental Protection Agency. 1981. Inter-Office Communication from K_A. Schultz, Chief, Emergency Response, to W.S.
Nichols, Director, Re: "Acid Ditch' Complaint." October 20.
24 Ohio Environmental Protection Agency. 1989. Letter from D. R. Parkinson, Division of Water Pollution Control, Ohio EPA, to
R. Marcus, Senior Environmental Scientist, ASARCO. September 22.
25 Ohio Environmental Protection Agency. 1974. Briefing memo. April 2.
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Chapter 14: Primary Zinc Processing 14-15
the conclusion that run-off and leachate from the on-site zinc slag were responsible for the excessive
loading.26 Water samples taken by the City of Columbus from the American Ditch, which bisects the facility,
showed cadmium and zinc concentrations above limits established by the City. Dissolved cadmium measured
0.56 mg/L while dissolved zinc measures 92.0 mg/L; the recorded pH was 2.6.27
A 1981 analysis performed by the City of Columbus on ASARCO's discharge to the American Ditch
showed that the discharge exceeded by several times the 3.0 mg/L City limit for zinc and that cadmium
concentrations were also above the 0.5 mg/L City limit.28 ASARCO was cited by the City for violations of
discharge limits for cadmium and zinc into the sewer system.29
Slag area run-off sampling data for September and October, 1986 revealed zinc concentrations of 26
mg/L and 46 mg/L, respectively. At that time, ASARCO agreed to begin removing the zinc slag from the
facility.30 In August 1987, the Ohio EPA described the situation at this facility by stating that, "[d]ue to past
practices over many years of dumping waste slag or clinker all over the site, there is still a problem with
contaminated run-off. There are documented problems with high concentrations of zinc and cadmium in the
run-off."31 In November 1987, ASARCO notified the City of its shipment off-site of 35,000 tons of zinc
slag.32
Recent testing has shown that the release of contaminants into surface waters has continued. An
Ohio EPA inter-office communication from June 1988 included a report which stated that "overall analysis
of cadmium and zinc concentrations from the Joyce Avenue outfall [ASARCO's discharge to the American
Ditch] suggests acutely toxic conditions exist on a frequent basis." For zinc, twenty percent of water samples
(5 percent for cadmium) taken from the ASARCO treatment center outfall were reported to have exceeded
the Final Acute Value limits (188 /ng/L for cadmium and 1,298 ptg/L for zinc) established for American Ditch
to protect against rapidly lethal conditions within a water body.
ASARCO, El Paso, Texas
This facility contains combined deposits of lead, copper, and zinc slag. Heavy metal contamination
of surface water and sediment in the Rio Grande River has been linked to these slag deposits. This situation
is more fully described in Section 6.3.4, Damage Cases, for the copper sector.
Zinc Corporation of America, DePue, Illinois
Zinc Corporation of America's (ZCA) Illinois zinc plant is located just east of the Illinois River and
Lake DePue, in Bureau County. The facility was originally owned by New Jersey Zinc Company, Inc. which
later changed its name to Zinc Corporation of America. Its parent company is Horsehead Resources. From
1905 until 1966, New Jersey Zinc operated a zinc smelter, sulfuric acid plant, phosphoric acid plant and
diammonium phosphate plant at this facility. In 1966, Mobil Chemical Company purchased all plants except
26 Ohio Environmental Protection Agency. 1974. Briefing memo. April 2.
27 Ohio Department of Health. 1972. Note from J. Shea (sic) to F. Klengalhafed (sic), Re: Water Samples taken by City of Columbus
from the ASARCO stream on the company's property. August 3.
28 City of Columbus, 1961, og. at.
29 City of Columbus. 1981. Letter from R. C. Parkinson, Director, Department of Public Service, to N. S. Geist, Superintendent
ASARCO. November 23.
30 City of Columbus. 1986. ASARCO Meeting. Representatives from Columbus Division of Sewerage and Drainage, Ohio EPA and
ASARCO. October 30.
31 Ohio Environmental Protection Agency. August 24,1987. Inter-office communication from L. Korecko and C Chao through W.
McCarthy, CDO-DWPC, to R. Mehlnop, CDO-DWQMA, Re: Use Evaluation, Toxics Evaluation, Heavy Metals Allocation, etc. for
ASARCO in Columbus.
32 The facility indicated that some slag (about 3,000 tons) had not been removed from the site due to possible PCB contamination
resulting from a spill at an adjacent facility.
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14-16 Chapter 14: Primary Zinc Processing
the zinc smelter, which ZCA operated until 1971. Currently, there are approximately 26 employees producing
zinc dust from zinc
Zinc smelting wastes were deposited in one pile at the southern end of the site that covers
approximately 10 acres and ranges in height up to 50 feet. In addition, there are also a number of smaller
piles on the site which measure approximately 100 feet in length and 10 to 12 feet in height. These smaller
piles may contain zinc slag in addition to other materials. Mobil Chemical Company did not purchase the land
on which the slag piles are located and this property is still owned and controlled by Zinc Corporation of
America.36'37
As early as 1967, the predecessor agency to the Illinois Environmental Protection Agency (EPA), the
Illinois Sanitary Water Board, suspected rainfall run-off contamination from zinc slag piles located on
New Jersey Zinc's property.38 The Illinois EPA monitored the surface run-off and leachate from the zinc
slag pile from 1973 to 1986. These analyses consistently showed levels of zinc, cadmium, copper, manganese,
and lead in excess of the maximum contaminant levels for drinking water. For example, from March 5, 1973
to March 26, 1986, run-off samples which exceeded the established MCLs for drinking water from the slag
pile ranged from 39 - 4000 mg/L for zinc (MCL = 5.0 mg/L); 0.5 - 3.6 mg/L for lead (MCL = .05 mg/L);
2.32 - 780 mg/L for manganese (MCL = 0.05 mg/L); 1.38 - 137.5 for copper (MCL = 1.3); and, 0.58 - 19.3
mg/L for cadmium (MCL = 0.01 mg/L). Run-off control measures (i.e., capping) have helped to reduce the
levels of contaminant discharge. Surface water samples taken during April, May, and June of 1989 (after
remedial controls were implemented at the facility) show the following range of concentration levels: zinc,
44.0 - 75.2 mg/L; lead, 0.05 - 0.06 mg/L; manganese, 1.8 - 3.83 mg/L; copper, 3.2 - 4.4 mg/L; and cadmium,
0.18 - .79 mg/L.39,40,41,42,43,44
Due to repeated problems in meeting effluent standards from this site, Zinc Corporation of America
received a five-month discharge variance in April 1988, and a five-year extension to this variance in January
1989. Discharge monitoring reports submitted by the facility for the fourth quarter 1989 indicate that few
33 Illinois Environmental Protection Agency. December 11,1975. Letter from B J. Revak to D.R. Baker, NJZ, Re: The New Jersey
Zinc Company (Bureau Country), Illinois Environmental Protection Agency File #2794.
34 Illinois Environmental Protection Agency. July 12,1982. NPDES Permit No. ILOOS2183 for the New Jersey Zinc Company, Inc.,
DePue, Illinois.
35 Illinois Pollution Control Board. April 7,1988. Order of the Borad regarding Petition for Variance of Consent Order.
36 Illinois Environmental Protection Agency. December 11,1975. Letter from BJ. Revak to D.R. Baker, NJZ, Re The New Jersey
Zinc Company (Bureau Country), Illinois Environmental Protection Agency File #2794.
37 Illinois Pollution Control Board. on. tit.
38 Illinois Environmental Protection Agency. May 12,1977. Memorandum from D.P. Duffy to DWPC/FOS and Records Unit, Re:
Mobil Chemical Company at DePue - Re: IL0032182 and New Jersey Zinc Company - EPA File #2794.
39 Illinois Environmental Protection Agency. March 5,1973. Memorandum from L.W. Eastep to Division of Water Pollution Control,
Surveillance Section, Re: New Jersey Zinc/Mobil Oil Company - Report of Operational Visit
40 Illinois Environmental Protection Agency. June 12,1975. Memorandum from CD. Miller to DQPC/FOS, Re: New Jersey Zinc -
Mobil Chemical Company (DePue).
41 Illinois Environmental Protection Agency. September 22,1975. Memorandum from CD. Miller to DWPC/FOS, Re: New Jersey
Zinc - Sampling.
42 Illinois Environmental Protection Agency. August 20,1984. Memorandum from D J. Connor to DWPC/FOS and Records Unit,
Re: New Jersey Zinc - Sampling Visits.
43 Illinois Environmental Protection Agency. June 9, 1986. Memorandum from DJ. Connor and HJ. Chien to DWPC/FOS and
Records Unit, Re: New Jersey Zinc - Summary of findings.
44 Horsehead Resources. July 21, 1989. Letter from D.P. Schoen to K. Rogers, Illinois Environmental Protection Agency, Re:
Quarterly reports.
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Chapter 14: Primary Zinc Processing 14-17
surface water contamination problems remained.45 Monitoring data on the quality of ground water beneath
the slag piles were not available.
14.3.3 Findings Concerning the Hazards of Zinc Slag and Ferrosilicon
Based on a review of available data on the composition of processed zinc slag and ferrosilicon, the
wastes have seven to ten constituents present in concentrations that exceed the risk screening criteria. The
contaminants that appear to present the greatest potential for concern in the two wastes are chromium, lead,
manganese, and copper. Zinc concentrations in the processed slag, but not the ferrosilicon, could also
conceivably pose risk under mismanagement scenarios. Based on available data and professional judgment,
EPA does not believe either of the wastes exhibit the hazardous waste characteristics of corrosivity, reactivity,
or ignitability. Lead concentrations measured in leachate from both wastes using the EP test frequently exceed
the EP toxicity regulatory level. Using the SPLP test, however, neither of the wastes exceeded the EP toxicity
regulatory levels.
Based on a review of existing waste management practices and predictive modeling results, EPA
believes that processed zinc slag and ferrosilicon, as currently managed at the sole active zinc facility in
Monaca, PA, pose an overall low risk to human health and the environment. The relatively high precipitation
and ground-water recharge rates in Monaca, the permeable substrate, and the absence of liners or leachate
collection systems combine to yield a high theoretical potential for contaminants to seep into the ground.
However, the Agency predicts that metals leached from zinc slag and ferrosilicon at the Monaca facility would
be largely bound to subsurface soil and would not reach ground water in the useable aquifer within 200 years.
Similarly, there is a relatively high potential for slag and ferrosilicon contaminants to migrate into surface
water because the facility is only 60 meters from the Ohio River, the annual precipitation is high, the slope
of the land is relatively steep, and the waste management units lack stormwater run-off controls. The Ohio
River, however, is very large and EPA predicts that it can readily assimilate the chronic loading of
contaminants that is expected on a routine basis (the Agency's predicted annual average concentrations of
contaminants in the river are at least two orders of magnitude below human health and environmental
protection criteria). EPAs predicted concentrations of toxic constituents in the air caused by windblown dust
from the waste management units also create very low risks at potential off-site exposure points.
The lack of documented cases of damage caused by the wastes at the Monaca facility supports the
Agency's conclusion that zinc slag wastes at this facility pose a low risk. The two damage cases at inactive
sites, however, demonstrate the potential for zinc slag to cause environmental problems when not managed
properly. In particular, the damage cases demonstrate that the migration of contaminants from slag piles,
especially contaminant migration via stormwater run-off, can cause surface water degradation when piles are
maintained near small water bodies and not equipped with run-off controls.
14.4 Existing Federal and State Waste Management Controls
14.4.1 Federal Regulation
EPA is unaware of any federal management control or pollutant release requirements that apply
specifically to zinc slag or ferrosilicon. EPA has promulgated effluent discharge limitations for the primary
zinc smelting industrial category under authority of the Clean Water Act, but these regulations address
wastewater discharges from wet air pollution control scrubbers and process sources, not slag storage or
disposal (40 CFR 421). Federal air regulations applicable to zinc smelters apply to processing operations
rather than waste management operations such as slag disposal.
45 Honehead Resources. October 27,1989. Letter from D.P. Schoen to K. Rogers, Illinois Environmental Protection Agency, Re:
Quarterly reports.
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14-18 Chapter 14: Primary Zinc Processing
14.4.2 State Regulation
The single zinc processing facility currently active in the United States that generates smelting slag
is located in Monaca, Pennsylvania. Rather than regulating zinc slag as either a hazardous or solid waste, the
state of Pennsylvania addresses zinc slag under its "residuals" regulations. Proposed revisions to the state's
residuals regulations would require a substantial expansion in the scope of the management controls for zinc
slag disposal. The proposed rule also would require that the owners/operators certify that they have attempted
to reuse and/or recycle the waste before disposal, but apparently would not specify environmental controls for
the reuse of the materials. The current residuals rule imposes only limited permitting requirements. For
instance, although waste piles for permanent disposal must be permitted under current state residuals
regulation, Pennsylvania effectively has not implemented this requirement for slag piles because of
disagreements with industry on the status (i.e., storage versus disposal) of the piles. The state has not required
that the Monaca plant obtain a permit for its slag piles. Similarly, the state applies surface water and air (i.e.,
fugitive dust control) requirements on a case-by-case basis and generally in response to complaints or evidence
of environmental damage only. In summary, although the proposed residuals rule would impose notably more
stringent environmental controls on the management of zinc slag than the state currently requires, the exact
nature and extent of such controls cannot be predicted pending adoption and implementation of a final rule.
14.5 Waste Management Alternatives and Potential Utilization
The ZCA Monaca facility processes all of the slag emerging from the furnace (see section 14.2) to
isolate those portions that can be returned to the production process or otherwise utilized. The slag is
separated into four materials: reclaimed coke and zinc-rich fines, which are both recycled; ferrosilicon, which
is stockpiled until it can be sold to cast iron manufacturers; and processed slag, which may be disposed in a
slag pile or used is the facility's flyash landfill or in construction applications.
14.5.1 Waste Management Alternatives
The amount of zinc slag that is recycled can vary, depending on the amount of zinc and coke
contained in the slag. The amount of zinc and coke in the slag is largely a function of how efficiently the
retort furnace utilizes the feed materials, and the nature and quality of the ore and secondary materials being
fed to the smelting process. Both the retort furnace efficiency and feed materials can vary considerably from
run to run, and the facility adjusts the amount of zinc slag being returned to the process to extract the
maximum amount of zinc from the inputs (96-97 percent).46 Consequently, there is little potential for
further reducing the amounts of waste slag being generated by increasing recycling efforts.
14.5.2 Utilization
In 1988,17,000 and 28,000 metric tons of ferrosilicon and processed slag, respectively, which were
separated from the slag removed from the furnace, were sent to on-site storage/disposal piles. During the
same period, however, 32^00 metric tons of processed slag were removed from the slag piles for utilization.
While none of the ferrosilicon was sold in 1988, sales before and after 1988 have been reported.47 This
information, along with the relatively small on-site accumulations of ferrosilicon (48,000 metric tons) and
processed slag (63,500 metric tons) suggest that much of the zinc slag that cannot be recycled is being utilized
in the ways discussed below.
46 Personal communication, James D. Reese, Director of Environmental Affairs, Zinc Corporation of America, April 20,1990.
<7 Ibid.
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Chapter 14: Primary Zinc Processing 14-19
Utilization of Ferrosilicon to Produce Cast Iron
The ferrosilicon, which is magnetically separated from the rest of the zinc slag, is occasionally sold
to cast iron foundries as a source of iron. The amount of ferrosilicon sold to produce cast iron is largely a
function of the technical requirements of the cast iron producers and the relative prices of ferrosilicon and
scrap steel (competing materials). The 1988 slump in sales of ferrosilicon are attributed to the ferrosilicon
being over-priced. ZCA has since lowered the price of ferrosilicon and sales have increased.48
Utilization of Processed Slag as Drainage Material in Landfills
The processed slag is currently being used as a drainage material in the flyash landfill at the Monaca
facility. The flyash is generated by two 60 megawatt power plants that are located on-site and produce power
for the facility. The processed slag has been placed in a layer on the bottom of the flyash landfill and covered
with fabric (to prevent clogging by the flyash) before any flyash is added. In 1988, the facility used 27,000
metric tons of its processed slag in this fashion. ZCA also uses the two medium-sized fractions of processed
slag as a cover material to reduce dust from the flyash landfill. This practice was only recently begun, however,
so it has not yet been determined how much slag will be used in this way.
The use of processed zinc slag as a drainage material in flyash landfills should be at least as protective
of human health and the environment as disposing it in a slag pile. If the water captured by the leachate
collection system is treated to remove any constituents of concern or the slag serves to remove contaminants
from any flyash leachate, this practice should prove to be more protective of human health and the
environment than disposal in one of the slag piles (which do not have leachate collection/treatment systems).
Processed Slag as Railroad Ballast and Road Rock
Zinc slag from the Monaca facility has also been utilized as railroad ballast and road rock
(gravel).49'50'51 Approximately 23,900 metric tons of zinc slag were sold as railroad ballast in 1982 and
5,500 metric tons of processed slag were sold as gravel for roads, driveways, and parking lots in 1988.52*53
No information has been found to indicate that future levels of use will greatly exceed the current 5,500 metric
tons per year. It should be noted that only the two medium-sized fractions of processed slag are of the
preferred size for these applications.
With one exception, EPA believes that the use of processed slag as railroad ballast or road rock poses
risks comparable to those stemming from its disposal in slag piles. The exception is that use as road rock will
increase the potential for airborne releases of slag dust. The basis for this belief is that when the slag is used
on roads or driveways, it will be in closer proximity to people, and will also be subjected to crushing and dust
entrainment by passing vehicles. EPA does not, however, have sufficient information to determine whether
this is a significant concern.
"ibid,
49 PEI Associates, Inc., 1984. Overview of Solid Waste Generation. Management, and Chemical Characteristics: Primary Zinc Smeltine
and Refining, prepared for U.S. Environmental Protection Agency, Office of Reaserch and Development, Cincinnati, Ohio, Contract No.
68-03-3197, Work Assignment No. 3.
50 Zinc Corporation of America, 1989(a), pj>. cit.
51 Reese, g£. cit.
52 PEI Associates, Inc., og. cit.
53 Zinc Corporation of America response to EPA, 1989(a), og. cit.
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14-20 Chapter 14: Primary Zinc Processing
Utilization as an Aggregate in Asphalt Manufacturing
Processed zinc slag has been used as an aggregate in asphalt and as an anti-skid material, though tests
performed at Oklahoma State University on four types of zinc smelter slag indicate that it is not suitable for
use as an aggregate in portland cement concrete because of alkali-aggregate activity.54 ZCA reported that
while none of its processed slag is currently being sold as aggregate for asphalt, the technical suitability of and
markets for the material are being investigated.55-
It is not expected that using processed zinc slag as an aggregate in asphalt will alter the chemical
composition of the slag, but the potential for any of the slag constituents to enter the environment via leachate
or dust is expected to be less than for use as road rock or disposal in a slag pile.
14.6 Cost and Economic Impacts
Section 8002(p) of RCRA directs EPA to examine the costs of alternative practices for the
management of the special wastes considered in this report. EPA has responded to this requirement by
evaluating the operational changes that would be implied by compliance with three different regulatory
scenarios, as described in Chapter 2. In reviewing and evaluating the Agency's estimates of the cost and
economic impacts associated with these changes, it is important to remember what the regulatory scenarios
imply, and what assumptions have been made in conducting the analysis.
The focus of the Subtitle C compliance scenario is on the costs of constructing and operating
hazardous waste land disposal units. Other important aspects of the Subtitle C system (e.g., corrective action,
prospective land disposal restrictions) have not been explicitly factored into the cost analysis. Therefore,
differences between the costs estimated for Subtitle C compliance and those under other scenarios (particularly
Subtitle C-Minus) are less than they might be under an alternative set of conditions (e.g., if land disposal
restrictions had been promulgated for "newly identified" hazardous wastes). The Subtitle C-Minus scenario
represents, as discussed above in Chapter 2, requirements that might apply to any of the special wastes that
are ultimately regulated as hazardous wastes; this scenario does not reflect any actual determinations or
preliminary judgments concerning the specific requirements that would apply to any such wastes. Further, the
Subtitle D-Plus scenario represents one of many possible approaches to a Subtitle D program for special
mineral processing wastes, and has been included in this report only for illustrative purposes. The cost
estimates provided below for the three scenarios considered in this report must be interpreted accordingly.
In accordance with the spirit of RCRA §8002(p), EPA has focused its analysis on impacts on the firms
and facilities generating the special wastes, rather than on net impacts to society in the aggregate. Therefore,
the cost analysis has been conducted on an after-tax basis, using a discount rate based on a previously
developed estimate of the weighted-average cost of capital to U.S. industrial firms (9.49 percent), as discussed
in Chapter 2. \Vfcste generation rate estimates (which are directly proportional to costs) for the -period of
analysis (the present through 1995) have been developed in consultation with the U.S. Bureau of Mines.
In this section, EPA first outlines the way in which it has identified and evaluated the waste
management practices that would be employed by the affected primary zinc producer under different regulatory
scenarios. Next, the Agency discussed the cost implications of requiring these changes to existing waste
management practices. The last part of this section predicts and discusses the ultimate impacts of the
increased waste management costs faced by the affected zinc facility.
M Collins, RJ. and R.H. Miller, Availability of Mining Wastes and Their Potential for Use as Highway Material - Volume I:
Classification and Technical and Environmental Analysis. FHWA-RD-76-106, prepared for Federal Highway Administration, May 1976,
pp. 168-170, 178, 196, and 210.
55 Reese, ojx cit.
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Chapter 14: Primary Zinc Processing 14-21
14.6.1 Regulatory Scenarios and Required Management Practices
Based upon the information presented earlier in this chapter, EPA believes that zinc slag poses an
overall low risk to human health and the environment. Nonetheless, the special waste exhibits the hazardous
waste characteristic of EP toxicity. Accordingly, the Agency has estimated the costs associated with regulation
under Subtitle C of RCRA, as well as with two somewhat less stringent regulatory scenarios, referred to here
as "Subtitle C-Minus" and "Subtitle D-Plus," as previously introduced in Chapter 2, and as described in specific
detail below. The Agency's cost and impact analysis is limited to the single pyrometallurgical primary zinc
processor, the ZCA facility in Monaca, Pennsylvania.
In the following paragraphs, EPA discusses the assumed management practices that would occur under
each regulatory alternative.
Subtitle C
Under Subtitle C standards, hazardous waste that is managed on-site must meet the standards codified
at 40 CFR Part 264 for hazardous waste treatment, storage, and disposal facilities. Because zinc slag and its
residues are solid, non-combustible materials, and because under full Subtitle C regulation, hazardous wastes
cannot be permanently disposed in waste piles, EPA has assumed in this analysis that the ultimate disposition
of processed zinc slag and ferrosilicon would be in Subtitle C landfills. Because, however, current practice at
the Monaca facility is storage and/or disposal of these materials in waste piles, the Agency has assumed that
the facility would also construct a temporary storage waste pile (with capacity of one week's waste generation)
that would enable the operators to send the processed slag and ferrosilicon to on-site disposal efficiently. EPA
has assumed that the Monaca plant could not continue to sell or utilize the ferrosilicon and processed slag
as it does currently, and would dispose the total quantities of these materials in a lined landfill. EPA believes
that, because of cost considerations, ZCA would construct one on-site landfill that meets the minimum
technology standards specified at 40 CFR 264, rather than ship the material off-site to a commercial hazardous
waste landfill or build multiple landfills.
Subtitle C-Minus
A primary difference between full Subtitle C and Subtitle C-minus is the facility-specific application
of requirements based on potential risk from the hazardous special waste. Under the C-minus scenario, as
well as the Subtitle D-Plus scenario described below, the degree of potential risk of contaminating groundwater
resources was used as a decision criterion in determining what level of protection (e.g., liner and closure cap
requirements) would be necessary to protect human health and the environment. The Monaca facility was
determined to have a low potential to contaminate groundwater resources. Therefore, under the
Subtitle C-Minus scenario, the facility would be allowed to continue to operate its present storage waste piles,
though run-on/run-off and wind dispersal/dust suppression controls are assumed to be required for the units.
In addition, the storage units must undergo formal closure; they are assumed to be "clean closed" with all
inventory removed.
While under baseline conditions the ultimate disposition of processed slag and ferrosilicon is periodic
sale for utilization (i.e., not recycling); under this regulatory scenario EPA has assumed that neither material
could be utilized in this way due to its intrinsic hazardous waste characteristics. Therefore, the facility is
assumed to be required to operate a disposal waste pile. Because the facility is located in a low risk area, the
unit would not require a liner and could be capped with a simple revegetated soil layer at closure. Run-
on/run-off controls and groundwater monitoring would be required; both practices would continue during the
30 year post-closure care period.
Subtitle D-Plus
As under both Subtitle C scenarios, the facility operator would, under the Subtitle D-plus scenario,
be required to ensure that hazardous contaminants do not escape into the environment. Like the Subtitle C-
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14-22 Chapter 14: Primary Zinc Processing
Minus scenario, facility-specific requirements are applied to allow the level of protection to increase as the
potential risk to ground water increases. As the Monaca facility has low potential to contaminate ground-
water resources, the facility is assumed to be allowed to continue operating its storage waste piles under the
Subtitle D-Plus scenario. The waste piles would be retrofitted with run-on/run-off and wind dispersal/dust
suppression controls which, as under Subtitle C-Minus, must be maintained through closure and the post-
closure care period. While under baseline the ultimate disposition of ferrosilicon was sale for off-site
utilization (i.e., not recycling), under the Subtitle D-Plus regulatory scenario the waste (with its intrinsic
hazard) could not be sold for off-site use. Therefore, the facility is assumed to be required to operate a waste
pile for disposal of the ferrosilicon. As the unit is located in a low risk area, this disposal waste pile would
not require a liner; ground-water monitoring and capping at closure is assumed to not be required for
management units under Subtitle D-Plus when the ground-water contamination potential is low, although wind
dispersal/dust suppression controls must be maintained.
14.6.2 Cost Impact Assessment Results
Results of the cost impact analysis for the Monaca zinc smelter are presented for each regulatory
scenario in Exhibit 14-6. Under the full Subtitle C scenario, ZCA's annualized regulatory compliance costs
are estimated to be just under $5 million more than the baseline waste management costs (about 195 times
greater). Two thirds ($3.2 million) of the increased compliance costs would be for new capital expenditures.
Under the facility specific risk-related requirements of the Subtitle C-Minus scenario, costs of
regulatory compliance are, for the sector, about 72 percent less than the full Subtitle C costs. ZCAs
annualized compliance costs would be Sl.4 million more than the baseline waste management costs (about 55
times greater). The primary savings over the full Subtitle C costs, due to the consideration of risk potential,
are the relaxation of technical requirements and the ability to use disposal wastepiles. New capital
expenditures, nearly 83 percent less than under full Subtitle C, would account for about $555,000 of the
incremental C-Minus compliance costs (about 40 percent of the annualized compliance cost).
Regulation under the Subtitle D-Plus program is assumed to require the same management controls
as under Subtitle C-minus, with the exception that, because of the low risk classification, no ground-water
monitoring or capping at closure is required under this scenario. ZCA's annualized regulatory compliance
costs wo-'!d be $1.1 million more than the baseline waste management costs. This represents an increase of
about 42 times over baseline, but a decrease of 78 percent from the Subtitle C compliance costs, and a
decrease of 23 percent from estimated Subtitle C-Minus compliance costs.
14.6.3 Financial and Economic Impact Assessment
To evaluate the ability of the affected facility to bear these regulatory compliance costs, EPA
conducted an impact assessment consisting of three steps. First, the Agency compared the estimated costs to
several measures of the financial strength of the facility (in the form of financial impact ratios) to assess the
magnitude of the financial burden that would be imposed in the absence of changes in supply, demand, or
price. Next, in order to determine whether compliance costs could be distributed to (shared among) other
production input and product markets, EPA conducted a qualitative evaluation of the salient market factors
that affect the competitive position of domestic primary producers of zinc. Finally, the Agency combined the
results of the first two steps to arrive at predicted ultimate compliance-related economic impacts which would
have to be absorbed by ZCA. The methods and assumptions used to conduct this analysis are described in
Chapter 2 and in Appendix E-4 to this document
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Exhibit 14-6
Compliance Cost Analysis Results for Management of
Zinc Slag from Primary Processing^
Facility
Zinc Corporation of America - Monaca, PA
Total:
Ba*elln« WMte
Management Cost
Annual Total
($000)
25
25
Incremental Co*t* of Regulatory Compliance
SubttttoC
Annual
Total
($000)
4,922
4,922
Total
Capital
($000)
/
21,978
21,978
Annual
Capital
($000)
3,279
3,279
Subtitle C-Mhuw
Annual
Total
($000)
1,377
1,377
Total
Capital
($000)
3.717
3,717
Annual
Capital
($000)
555
555
Subtitle D-Plus
Annual
Total
($000)
1.058
1.058
Total
Capital
($000)
3.467
3.467
Annual
Capital
($000)
517
517
O
1)
<"1
I
I
3
O
•o
(a) Values reported In this table are those computed by EPA's cost estimating model, and are Included for Illustrative purposes. The data, assumptions, and computational
method* underlying these value* are such that EPA believes that the compliance cost estimates reported here are precise to two significant figures.
3
(O
£
CO
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14-24 Chapter 14: Primary Zinc Processing
Financial Ratio Analysis
Screening analysis of the financial ratios indicates that regulation of zinc slag under full Subtitle C
would have a potentially significant financial impact on the ZCA facility. As shown in Exhibit 14-7, annualized
compliance costs exceed five percent of value of shipments and eleven percent of value added. Annualized
compliance capital represents a full 45 percent of the average sustaining capital needed annually.
Under the Subtitle C-Minus and D-Plus scenarios, impacts are substantially less and only marginally
significant. Annual compliance costs as a percent of value of shipments is less than 1.5 percent under either
scenario; the percent of those costs to value added are 2-3 percent under the two scenarios. Under both
scenarios the annualized compliance capital is between 7 and 8 percent of the annual sustaining capital
investments.
Market Factor Analysis
General Competitive Position
In 1987, a total of 342,663 metric tons of slab zinc was produced by the four domestic zinc-producing
facilities; three facilities (which do not produce a special waste) used the electrolytic technique, and one facility
(ZCA-Monaca, which produces a special waste) used the pyrometallurgical technique. Domestic metal
production in 1988 was near annual capacity (approximately 400,000 metric tons). Strong demand and high
prices are expected to result in growth rates throughout the 1990's of 0-2.5 percent in the U.S., and greater
than 2.5 percent globally. The opening of one zinc mine in Idaho and the anticipated opening of two more
in Alaska are an indication that domestic zinc mine output will remain high. Secondary production has
increased steadily over the past five years from a low of 63,000 metric tons to an estimated 110,000 metric tons
in 1989; this sub-sector is expected to continue to meet a large portion of the domestic demand for zinc.
Domestic zinc consumption in 1988 rose in virtually all use categories, led by increases in galvanizing
and electro-galvanizing, and resulted in record-high imports of both slab zinc and zinc oxide. Both domestic
and global consumption of zinc are expected grow more than 2.5 percent per year throughout the 1990's.
Exhibit 14-7
Significance of Regulatory Compliance Costs for Management of
Zinc Slag from Primary Processing^
Facility
Subtitle C
Zinc Corporation of America • Monaca, PA
Subtitle C-Mlnus
Zinc Corporation of America - Monaca, PA
Subtitle D-Plu*
Zinc Corporation of America - Monaca, PA
CC/VOS
5.1%
1.4%
1.1%
CC/VA
11.4%
32%
2.4%
IR/K
45.4%
7.7%
7.2%
CC/VOS = Compliance Costs as Percent of Sales
CC/VA = Compliance Costs as Percent of Value Added
IR/K = Annualized Capital Investment Requirements as Percent of Current Capital Outlays
(a) Values reported in this table are based on EPA's compliance cost estimates. The Agency believes that these values
are precise to two significant figures.
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Chapter 14: Primary Zinc Processing 14-25
Potential for Compliance Cost Pass-through
Labor Markets. Approximately 2,100 people are employed in the mining and milling of zinc, and
1,500 people are employed in primary zinc smelting. No other information is currently available.
Lower Prices to Suppliers. While it may be possible to pass along a portion of increased costs
to suppliers, the partial integration of the zinc producers and zinc ore mines make it unlikely that very much
of the cost could be passed backwards.
Higher Prices. U.S. "High Grade" zinc currently costs about 5 cents more than its "Prime Western"
equivalent, indicating that an increase in U.S. prices would be infeasible without an equivalent rise in the
world price of zinc. However, with the currently tight supply-demand situation, world reserves of zinc have
fallen, resulting in record-high prices during the last quarter of 1988. Therefore, it appears that any affected
U.S. companies might be able to pass on somewhat higher costs in the form of higher prices if current
consumption trends continue.
Evaluation of Cost/Economic Impacts
Given the severe cost impacts which would be experienced by ZCA under full Subtitle C, and the
limited potential for long-term compliance cost pass-through, EPA believes that regulation of zinc slag under
full Subtitle C regulations would pose a threat to the economic viability of the ZCA facility. The estimated
compliance costs represent significant portions of the value added by zinc processing operations at the Monaca
plant, would be expected to exceed ZCAs operating margins, and would likely force ZCA to discontinue
operating the Monaca facility, at least as a primary zinc smelter.
Prospective impacts under Subtitle C-Minus regulation and, to a greater extent, under D-Plus
regulation, would be marginally significant at worst, as demonstrated by the results of the financial ratio
screening analysis. In addition, ZCA occupies a unique market niche as the only primary zinc processor with
smelter operations that can utilize scrap and other secondary materials which are not readily recoverable in
electrolytic zinc plants, as feedstocks, and ZCA/Monaca's upgraded energy efficient electrothermic furnaces
(installed in 1980) have served to lower production costs in recent years. Therefore, EPA believes that the
facility would be able to incur the estimated costs and continue operating in the currently strong zinc market.
If current zinc prices remain strong, ZCA might be able to raise prices sufficiently to offset some or all of its
compliance costs, at least in the short term. As an alternative, ZCA might also further process its ferrosilicon
in order to reduce its potential toxicity, thereby allowing sale for reprocessing. As a final option, ZCA could
adopt the practices of other smelter operations and shift to secondary processing, thereby decreasing or
eliminating the fraction of ore comprising its feedstock, and, presumably, reducing the generation rate of its
slag. In any case, EPA expects that regulation under the Subtitle C-Minus or D-Plus regulatory scenarios
would not significantly affect the facility or threaten its continued economic viability.
14.7 Summary
As discussed in Chapter 2, EPA developed a step-wise process for considering the information
collected in response to the RCRA §8002(p) study factors. This process has enabled the Agency to condense
the information presented in the previous six sections of this chapter into three basic categories. For each
special waste, these categories address the following three major topics: (1) potential for and documented
danger to human health and the environment; (2) the need for and desirability of additional regulation; and
(3) the costs and impacts of potential Subtitle C regulation.
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14-26 Chapter 14: Primary Zinc Processing
Potential and Documented Danger to Human Health and the Environment
The intrinsic hazard of processed slag and ferrosilicon from zinc processing is relatively high compared
to other mineral processing wastes studied in this report. Based on EP leach test results, 25 out of 36 samples
of processed slag and 1 out of 1 sample of ferrosilicon from the Monaca facility contain lead concentrations
in excess of the EP toxicity regulatory levels. Lead concentrations measured in SPLP (EPA Method 1312)
leachate, however, were well below the EP regulatory levels. In addition, processed zinc slag contains five
constituents in concentrations that exceed the conservative screening criteria used in this analysis by more than
a factor of 10. Ferrosilicon contains four constituents in concentrations greater than 10 times the conservative
screening criteria.
Based on a review of existing waste management practices and predictive modeling results, EPA
believes that processed zinc slag and ferrosilicon, as currently managed at the active zinc facility in Monaca,
PA, pose an overall low risk to human health and the environment. The relatively high precipitation and
ground-water recharge rates in Monaca, the permeable substrate, and the absence of liners or leachate
collection systems combine to yield a high theoretical potential for contaminants to seep into the ground.
However, the Agency predicts that metals leached from zinc slag and ferrosilicon at the Monaca facility would
be largely bound to subsurface soil and would not reach ground water in the useable aquifer within 200 years.
Similarly, there is a relatively high potential for slag and ferrosilicon contaminants to migrate into surface
water because the facility is only 60 meters from the Ohio River, the annual precipitation is high, the slope
of the land is relatively steep, and the waste management units lack stormwater run-off controls. The Ohio
River, however, is very large and EPA predicts that it can readily assimilate the chronic loading of
contaminants that is expected on a routine basis (the Agency's predicted annual average concentrations of
contaminants in the river are at least two orders of magnitude below human health and environmental
protection criteria). EPA's predicted concentrations of toxic constituents in the air caused by windblown dust
from the waste management units also create very low risks at potential off-site exposure points.
The lack of documented cases of damage caused by the wastes at the Monaca facility supports the
Agency's conclusion that zinc slag wastes managed at this facility pose a low risk. The damage cases at inactive
sites, however, demonstrate the potential for zinc slag to cause environmental problems when not managed
properly. In particular, the damage cases demonstrate that the migration of contaminants from slag piles,
especially contaminant migration via stormwater run-off, may cause significant surface water degradation when
piles are maintained near small water bodies and not equipped with run-off controls. (Although some of the
management units at the Monaca Plant are not equipped with run-off controls, surface water impacts are
limited by the large flow of the Ohio River.)
Likelihood That Existing Risks/Impacts Will Continue in the
Absence of Subtitle C Regulation
Although zinc slag wastes are expected to maintain a relatively high intrinsic hazard in the future, the
waste management practices and environmental conditions that currently limit the potential for significant
threats to human health and the environment at the Monaca facility are expected to continue to limit risks
in the future in the absence of Subtitle C regulation. The characteristics of these wastes are unlikely to change
in the future, and no new zinc smelters that would produce these wastes are expected to commence operation
in the near future. A portion of the zinc slag is sold for use at off-site locations as road gravel or construction
aggregate, and ferrosilicon is stockpiled until it can be sold for off-site use as a source of iron. Because these
off-site locations could be conducive to releases and risks at present and in the future, this analysis of the
potential and documented dangers of these wastes at the Monaca facility may underestimate the risks
associated with these wastes at other locations. EPA is concerned that some types of slag and ferrosilicon
utilization may not be protective of human health and the environment and plans to investigate methods to
ensure that all slag uses are protective.
At this time, Pennsylvania does not regulate zinc slag wastes as either hazardous or solid wastes.
Rather, the state addresses zinc slag under its 'residuals' regulations. The current residuals rule imposes only
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Chapter 14: Primary Zinc Processing 14-27
limited permitting requirements, and the state has not required that the Monaca facility obtain a permit for
its slag piles. Moreover, the State applies surface water and fugitive dust control requirements on a case-by-
case basis and generally only in response to complaints or evidence of environmental damage. Proposed
revisions to the state's residuals rule, however, would require a substantial expansion in the scope of the
management controls for zinc slag disposal. The revised rule also would require that the owners/operators
certify that they have attempted to reuse and/or recycle the waste before disposal, but apparently would not
specify environmental controls for the reuse of the materials. It is not clear at this time how the rule may
address inactive or abandoned units.
Costs and Impacts of Subtitle C Regulation
Because EPA waste sampling data indicate that processed slag and ferrosiliicon from the Monaca
facility may exhibit the hazardous waste characteristic of EP toxicity, the Agency has evaluated the costs and
associated impacts of regulating these materials as hazardous wastes under RCRA Subtitle C. As with the
other aspects of this study, the Agency's cost and impact analysis is limited in scope to the facility at
Monaca, PA.
Costs of regulatory compliance approach $5 million annually under the full Subtitle C regulatory
scenario, while regulation under the more flexible standards.of the Subtitle C-Minus scenario imply compliance
costs of about $1.4 million annually, a reduction of 72 percent over full Subtitle C costs. Incremental costs
under the Subtitle D-Plus scenario are just over $1 million annually. Subtitle C costs represent a significant
fraction (more than eleven percent) of the value added by the Monaca operation, and would require capital
expenditures exceeding 45 percent of the annual capital currently required to sustain production at this facility.
Estimated Subtitle C-Minus and Subtitle D-Plus costs are estimated from one to three percent of the value
of shipments of and value added by the facility. EPA's economic impact analysis suggests that the operator
of the potentially affected facility (ZCA) would have only a limited ability to pass through a portion of any
regulatory compliance costs that it might incur to product consumers, because of competition from other,
unaffected zinc producers, both domestic and foreign. Because of these factors, EPA believes that a decision.
to regulate slag from primary zinc production under RCRA Subtitle C could adversely affect the ability of the
Monaca facility to continue to compete successfully over the long-term, while the estimated costs associated
with the Subtitle C-Minus and D-Plus scenarios are not likley to result in significant impacts.
Finally, EPA believes that incentives for recycling or utilization of zinc slag would be mixed if a
change in the regulatory status of this waste were to occur. In-process recycling is the current managment
practice that is applied to zinc slag. It is possible that tighter regulatory controls on the management of
primary zinc slag and its residues might serve to promote even greater recycling and on-site utilization than
has occurred in the recent past. Utilization of processed zinc slag in construction and other off-site
applications has been reported, but is not widely practiced at present, while utilization of ferrosilicon as a
feedstock for producing cast iron by foundries has been occurring for some time. It is likely that removing
zinc slag from the Mining Wute Exclusion and thereby subjecting it to regulation as a hazardous waste would,
in practical terms, eliminate the off-site use of processed slag in construction applications, and of ferrosilicon
as a source of iron in cast iron foundries.
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Glossary1
Acid Plant Slowdown: \teters that have been used in an acid plant and that have accumulated contaminants
to such an extent that they are removed from the system.
Acute Exposure: Exposure to a substance for a short period of time.
Adsorption Coefficient (Kd): A measure of the degree to which constituents bind to a material (e.g., the soil).
Aggregate: A rock material such as sand, gravel, or crushed rock with which cement or bitumen is mixed to
form a mortar or concrete.
Alkaline: A synonym for basic (i.e., pH greater than 7).
Alumina: Aluminum oxide, A12O3, an important constituent of all clays, determining their suitability for
firebrick and furnace linings; also, used in granular form for abrasive purposes.
Amalgamation: The process by which mercury is alloyed with some other metal to produce an amalgam.
Ambient: The area surrounding the facility or residual management unit. "Ambient" monitoring data refers
to pollutant measurement data from the medium (e.g., air, surface water) to which the pollutants are
discharged, not to measurements of the discharge itself.
Anhydrous: Minerals which do not contain water in chemical combination.
Anode: The positive electrode in an electrolytic cell.
Anode Coppen Special-shaped copper slabs, resulting from the refinement of blister copper in a furnace, used
as anodes in electrolytic refinement.
Anode Metals: Metals (e.g., copper) used for electroplating. They are as pure as commercially possible,
uniform in texture and composition, and have the skin removed by machining.
Aquifer A subsurface formation containing water in quantities sufficient to be withdrawn.
1 Many of the glossary definitions are taken from the Dictionary of Mining. Mineral, and Relating Terms, compiled and edited by P.W.
Thrush and Staff of the Bureau of Mines, U.S. Dept. of the Interior, Bureau of Mines, 1968.
-------
G-2 Glossary
Baghouse: Chamber in which exit gases (e.g., from roasting, smelting, and calcining) are filtered through
membranes (bags) which arrest solids.
Bauxite: A mineral composed of one or more aluminum hydroxides (e.g., boehmite, gibbsite, and diaspore)
and impurities such as silica, clay, silt, and iron hydroxide; essentially, A12O3 • 2H2O. A clay containing much
bauxite should be termed bauxite.
Beneficiation: The following activities: crushing, grinding, washing, dissolution, crystallization, filtration,
sorting, sizing, drying, sintering, pelletizing, briquetting, calcining to remove water and/or carbon dioxide,
roasting in preparation for leaching, gravity concentration, magnetic separation, electrostatic separation,
flotation, ion exchange, solvent extraction, electrowinning, precipitation, amalgamation, and heap, dump, vat,
tank, and in situ leaching.
Bleed Electrolyte: Electrolyte from electrolytic metal refining that has accumulated contaminants to such an
extent that it must be removed from the system.
Blister Copper: An impure (98.5 - 99.5 percent) intermediate product in the refining of copper, produced by
blowing copper matte in a converter, the name being derived from the large blisters on the cast surface that
result from the liberation of SO2 and other gases.
Brine: Water with a high (e.g., greater than sea water) salt concentration.
Briquetting: A process by which coke breeze, coal dust, iron ore, or other pulverized mineral commodities
is bound together into briquettes, under pressure, with or without a binding agent such as asphalt.
By-Product Manufacturing Unit: A management unit that receives a residual as a feedstock and produces a
saleable product or intermediate product.
Calcination: Heating an ore or mineral product or intermediate product in a furnace or kiln to decompose
carbonates, hydrates, or other compounds to produce a final product. The process is different from roasting
in that air is not supplied to the charge during heating.
Cancer Risk: The estimated probability of occurrence of cancer in an individual, over that individual's
lifetime.
Capacity: The maximal annual output of a particular processing operation, irrespective of market conditions.
This limit may be determined by either design constraints or permit limitations.
Carcinogen: A chemical for which there is sufficient evidence that it can cause cancer in humans.
Cathode: The negative electrode in an electrolytic cell.
-------
Glossary G-3
Cementitious: Having the property of or acting like cement (see Pozzolanic) (e.g., certain limestones and tuffs
when used in the surfacing of roads).
Chemical Conversion: A mineral processing operation in which an ore or mineral or beneficiated ore or
mineral is treated with one or more chemicals in order to initiate a reaction that liberates and/or changes the
chemical form of the ore value(s). Examples include sulfuric acid digestion of phosphate ore and of titanium
ore.
Chronic Exposure: Exposure to a substance over a long period of time.
Closure Plan: A written plan that identifies and describes the steps that will be carried out to close, dismantle,
decommission, and/or reclaim a residuals management unit at a mineral processing facility.
Constituent- A chemical or radiological agent (e.g., arsenic or radium-226) present in a waste.
Corrosivity: One of the four characteristics of hazardous waste as defined by EPA, based upon pH values of
less than 2.0 or greater than 12.5 (see 40 CFR §261.22).
Crushing: Reducing ore by stamps, crushers, or rolls.
Cryolite: A halide mineral, Na3Al • F^ used in the reduction of aluminum ore.
Crystallization: The process through which crystalline phases separate from a fluid.
Cutoff Grade: The lowest grade of mineralized rock that qualifies as ore in a given deposit.
Dewatering: The removal of water from a material by pumping, drainage, filtration, or evaporation.
Dissolution: The process of dissolving or breaking up into a liquid.
Dolomite: A carbonate of calcium and magnesium, CaMg(CO3)2.
Down Gradient: The direction of ground-water flow caused by difference in hydraulic head at two locations
(from the highest to the lowest hydraulic head).
Dross: The scum that forms on the surface of molten metals largely because of oxidation but sometimes
because of the rising of impurities to the surface.
Drying: The removal of water from ores, concentrates, fluxes, or other materials.
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G-4 Glossary
Dump Leaching: A beneficiation operation most often used to extract metal values from subore-grade
materials in the copper industry, in which dilute acid or water is percolated through piles of low grade ore or
tailings. The dilute metal solution generated is collected at the bottom of the pile (dump), and is subjected
to one or more downstream extraction operations to recover the metal values.
Effluent- A liquid, solid, or gaseous product, frequently waste, discharged or emerging from a process.
Electrogalvaniring: The electroplating of zinc upon iron or steel.
Electrolyte: A substance that when dissolved in a suitable solvent or when fused becomes an ionic conductor.
Electrolytic: Pertaining to the use of electrolysis; applied to the refining of metals by deposition from solution.
Electrostatic Separation: A method of separating materials by dropping feed material between two electrodes,
positive and negative, rotating in opposite directions. Nonrepelled materials drop in a vertical plan;
susceptible materials are deposited in a forward position somewhat removed from the vertical plane.
Electrowinning: The process of refining copper or other metals by the dissolution of the metal bearing ore
in an acidic solution, the introduction of the solution as an electrolyte in an electrolytic cell, and the
deposition of the metal from solution by application of electric current.
Endangered Species Habitat: The natural surroundings of any plant or animal that is considered endangered
or threatened by federal or state governments.
EP Toxicity (Extraction Procedure Toxidty): One of four characteristics of hazardous waste as defined by
EPA (see 40 CFR §261.24). Materials that are shown to leach one or more of 14 hazardous constituents at
concentrations exceeding 100 times primary drinking water standards are considered EP toxic. These
constituents include arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver, endrin, lindane,
methoxychlor, toxaphene, 2,4-D, and 2,4,5-TP Silvex.
Exposure Pathway: The way a chemical or physical agent comes into contact with humans or the environment.
Extraction: The process of mining and removing ores or minerals from the ground.
Facility: All mining, beneficiation, processing, fabrication/manufacturing, and residuals management units
within property boundaries controlled by one operating company.
Fault Area: A geographic region of any size that has been seismically active (i.e., has had displacement or
movement) during holocene time (approximately the last 11,000 years).
Ferrosilicon: An alloy of iron and silicon, used in steel and corrosion-resistant cast iron.
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Glossary G-5
Filtration: A process for separating solids from liquids by allowing the liquid to pass through a material which
retains the solids.
Floodplain: The portion of a river valley, adjacent to the river channel, that is built of sediments during the
present regimen of the stream and which is covered with water when the river overflows its banks at flood
stages.
Flotation: See Froth Flotation.
Fluorogypsum: See Gypsum.
Froth Flotation: A floatation process in which the minerals floated gather in and on the surface of bubbles
of air or gas driven into or generated in the liquid in some convenient manner.
Fuming: A process whereby fine particles are dispersed in a gaseous phase prior to recovery in condensers;
used in the recovery of zinc from the slag generated in lead smelting.
Gravity Concentration: Separating grains of minerals by a concentration method operating by virtue of the
differences in density of various mineral; the greater the difference in density between two minerals, the more
easily they can be separated.
Grinding: Size reduction into relatively fine particles.
Ground-Water. Water contained within a subsurface formation.
Gypsum: A common evaporite mineral, CaSO4, with a variety of uses in construction materials and
agriculture. Mined gypsum is generally referred to as natural gypsum, whereas gypsum produced by the
neutralization of sulfuric acid from phosphoric acid or hydrofluoric acid production is referred to as
phosphogypsum and fluorogypsum, respectively. Depending on temperature, pH, and the availability of water,
gypsum can exist in a variety of forms: anhydrite, CaSO4; hemihydrate, CaSO4 • V£H2O; and dihydrate,
CaSO4-2H2O.
Gypsum Stack: A residuals management unit that is used to store or dispose of the gypsum produced by
acidulation of phosphate rock or feldspar. Active stacks will generally be used for water management as well
as gypsum disposal.
Heap Leaching: A beneficiation process in which low grade ore containing valuable metals is piled on an
impervious surface (pad) then treated with water or a dilute solution (often containing cyanide). The solution
preferentially dissolves metals, such as gold and silver, which are recovered by collecting the solution and
extracting the metals.
Hydrolysis: The formation of an acid and a base from a salt by interaction with water.
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G-6 Glossary
Hydrometallurgy: Recovery of metals from ores by a liquid process such as leaching with acid, or solvent
extraction.
Ignitability: One of the four characteristics of a hazardous waste as defined by EPA (see 40 CFR §261.21),
based upon the ability to combust at or near 140 degrees, or to cause fire through friction, or if it is an
ignitable compressed gas, or is an oridizer.
Ilmenite: An iron black mineral, FeO • TiO2.
Intermediate: A material produced during the beneficiation or processing of materials, ores, and minerals and
which are further processed to recover a usable product or returned to the original process or processes and
reused in the production process.
Intrinsic Hazard: The ability of a chemical to harm humans or the environment, if of release and exposure
are assumed to occur.
Ion Exchange: The reversible exchange of ions contained in a crystal for different ions in solution without
destruction of crystal structure or disturbance of electrical neutrality.
Leachate: A solution formed by dissolving the soluble fraction of a waste or ore into a liquid.
Leaching: The dissolution of chemical constituents from an ore, mineral, beneficiated ore or mineral, or
processed ore or mineral by applying water or a solution to the material.
Lignite: A soft brownish-black coal in which the alteration of vegetal material has proceeded further than peat
but not so far as subbituminous coal.
Lime: Quicklime (CaO) obtained by calcining limestone or other forms of calcium carbonate.
Linen A material used in sealing the bottoms of residual management units so as to prevent leakage of
contaminants into the environment. Liner materials range from bedrock and in-situ clay to synthetic plastics.
Magnetic Separation: The separation of materials from nonmagnetic materials using a magnet
Matte: A metallic sulfide mixture made by the smelting of sulfide ores of copper, lead, and nickel.
Maximally Exposed Individual (MEI): An individual designated for each exposure pathway, to be at the
greatest risk to constituents released to the environment
Milling: The process of grinding or crushing ores into fine fractions for removal of valueless or harmful
constituents.
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Glossary G-7
Mining: The minerals industry which supplies the community with coal, minerals, or metal raw materials and
includes production of primary products, for example, copper from porphyry copper ore.
NESHAP (National Emission Standards for Hazardous Air Pollutants): Air pollutant emission standards for
specific contaminants that have been shown to be dangerous to human health.
OOlite: Limestone rock (calcium carbonate) of the Jurassic system consisting of small round grains, resembling
fish roe, cemented together.
Overburden: Overlying soil, gravel or rock that is removed in the process of mining.
Pelletizing: A method in which finely divided material is rolled in a drum or on an inclined disk, so that the
panicles cling together and roll up into small spherical pellets.
Permeability: The capacity of subsurface strata to transmit a fluid, expressed as the rate at which a fluid of
standard viscosity (e.g., water) can move a specified distance. Permeability is dependent on the size and shape
of pores in the stratum or strata, the size and shape of interconnections between pores, and the extent of these
interconnections.
Phosphogypsum: See gypsum.
Pilot Scale: A demonstration or test of a process which is not full-size, but it too large to be done in a
laboratory.
Pozzolanic Able to react with lime in the presence of water at ordinary temperature to produce a
cementitious compound.
Precipitation: In mineral processing, the process of separating mineral constituents from a solution by because
of lowered solubility, usually caused by lowering the temperature of the solution.
Process Wastewaten Waters used or generated in one or more production operations that have accumulated
contaminants to such an extent that they must be removed.
Pyrolysis: The transformation of a compound into another substance through the addition of heat.
Pyrometallurgy: Ore and mineral processing in which feedstocks are subjected to high temperatures in order
to separate and remove impurities from the mineral value(s). Examples of pyrometallurgical operations
include smelting and roasting.
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G-8 Glossary
RCRA (Resource Conservation and Recovery Act): The federal statute (P.L. 94-580, as amended) that
provides EPA with the authority to regulate the treatment, accumulation, storage, disposal, and reclamation
of solid and hazardous wastes.
Recycling: The return of a mineral processing residual back to the mineral processing operation that
generated the material.
Refining: Mineral processing that removes impurities from an ore or mineral, beneficiated ore or mineral,
or partially processed (e.g., smelted) ore or mineral.
Residuals: Materials that are generated as a consequence of processing an ore or mineral and that are not
the principal product(s) of the operation. Examples include but are not limited to co- and by-products, wastes,
feedstocks for further processing operations, and recycled materials. Responses to questions pertaining to
specific residuals should focus on the point in the process at which the residual is generated.
Retort: A vessel used for the distillation of volatile materials, as in the separation of some metals and the
destructive distillation of coal.
Reverberatory Furnace: A furnace in which heat is radiated from the roof onto the material under treatment;
commonly used in the smelting of metals.
Roasting: Heating an ore or mineral or beneficiated ore or mineral with access to air, in order to effect a
chemical change (e.g., expulsion of volatile material) without fusing or melting.
Secondary Material: As used in this report, a material, commonly referred to as "scrap material," which is bits
and pieces of metal parts (e.g., bars, turnings, rods, sheets, or wires), which when worn or superfluous is used
as feedstock in the processing of primary ores and minerals.
Sinter To heat a mass of fine particles for a prolonged time below the melting point, usually to cause
agglomeration.
Sizing: The process of separating mixed particles into groups of particles all of the same size, or into groups
in which all particles range between definite maximum and minimum sizes.
Sludge: A soft mud, slush, or mire; for example, the solid product of a filtration process before drying.
Slurry Walls: An type of a containment system that prevents leachate from migrating through ground water
systems. Typically, slurry walls are formed in place by excavating a trench outside the edge of a waste
management unit or ground-water contaminant plume, mixing the removed native materials with a grout (e.g.,
bentonite clay, cement, asphalt), and immediately redepositing the slurried mixture in the trench.
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Glossary G-9
Smelter Slag: The nonmetallic top layer consisting primarily of silicates and aluminosilicates of lime or other
bases, which separates from the metallic products in the smelting of ores.
Smelting: The chemical reduction of a metal from its ore by a process that usually involves fusion, so that
the impurities in the material, separating as lighter and more fusible slags, can be readily removed from the
reduced metal, or other thermal processing wherein chemical reactions take place to produce liquid metal from
a benefitiated ore.
Solvent Extraction: A method of separating one or more substances from a mixture, by treating a solution
of the mixture with a solvent that will dissolve the required substances, leaving the others.
Sorting: The process of selecting one or more portions of some material on the basis of a particular
characteristic (e.g., size or density).
Source Reduction: The diminution or elimination of solid and/or hazardous waste at the point of generation,
usually within a process.
Speiss: Metallic arsenides and antimonides smelted from cobalt and lead ores.
Tailing(s): The residual arising from the washing, concentration, and/or treatment of ground ores or minerals
(beneficiation).
Tailings Pond: A residuals management unit used for disposing tailings. Tailings ponds are typically bounded
by a raised earthen embankment.
Tltaniferrous: Carrying titanium, as titaniferrous iron ore (see ilmenite).
Treatment: An operation that induces a physical or chemical change in a mineral processing residual.
Vulnerable: A physical setting which facilitates the release and transport of contaminants (e.g., karst terrain),
and/or a setting which is especially sensitive to contaminants.
Washing: The process of cleaning, carrying away, or eroding by the buoyant action of flowing water.
Waste Management Unit: Any location at which residuals are treated, stored, accumulated, recovered for
reuse, or disposed.
Waste Pile: As used in this report, an above ground accumulation of material which may be temporary or
permanent.
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REPORT TO CONGRESS
ON
SPECIAL WASTES FROM MINERAL PROCESSING
Appendices
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Table of Contents
Page
Volume III: Appendices
APPENDIX A History of the Mining Waste Exclusion for
Mineral Processing "Wastes
APPENDIX B EPA Data Collection Activities
B-l Description of the 1989 National Survey
of Solid Wastes from Mineral Processing
Facilities (SWMPF Survey) B-l-1
B-2 Description of 1989 EPA Sampling and
Analysis Activities B-2-1
B-3 List of Facilities With Documented Cases of
Damage from Mineral Processing Waste B-3-1
B-4 Example of RCRA §3007 Data Request B-4-1
B-5 List of Published Reports, Papers,
Abstracts, and Data B-4-1
APPENDIX C Risk Assessment Criteria and Model
C-l Risk Assessment Screening Criteria C-l-1
C-2 Summary of MMSOILS Model C-2-1
APPENDIX D Existing Regulatory Controls
D-l Existing Federal Regulatory Controls
Addressing Mineral Processing Wastes D-l-1
D-2 Existing Regulatory Controls Addressing
Mineral Processing Wastes in Selected States D-2-1
APPENDIX E Cost and Economic Impact Assessment
Methodology, Assumptions, and Results
E-l RCRA Subtitle C Statutory and
Regulatory Provisions E-l-1
E-2 Subtitle D-Plus Regulatory Program Scenario E-2-1
E-3 Description of Cost Model and Assumptions E-3-1
E-4 Sources of Market and Financial Data E-4-1
E-5 Results of Financial Impact Analysis E-5-1
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Appendix A
History of the Mining Waste Exclusion
for Mineral Processing Wastes
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Appendix A
History of the Mining Waste Exclusion for
Mineral Processing Wastes
1. Introduction
Since the proposal of the first regulations under the Resource Conservation and Recovery Act
(RCRA) in 1978, mineral processing wastes have been subject to a different regulatory framework than most
other categories of potentially hazardous wastes. In the 1978 proposed rule implementing Subtitle C of
RCRA, EPA introduced the "special waste" concept, which was based on the belief that these "special wastes"
should, on a provisional basis, be regulated less stringently than other wastes because they were produced in
very large volumes, were thought to pose less of a hazard than other wastes, and were generally not amenable
to the management practices required by the technical standards being proposed for other hazardous wastes.
In 1980, Congress made this "special waste" concept a statutory requirement when it enacted the Bevill
Amendment as part of the 1980 amendments to RCRA. The Bevill Amendment temporarily exempted fossil
fuel combustion wastes, oil and gas field production wastes, mining and mineral processing wastes, and cement
kiln dust waste from potential regulation as hazardous wastes under Subtitle C of RCRA.
This Appendix provides a summary of the history of the Federal Mining Waste Exclusion, from the
initial enactment of RCRA through the present
2. The Resource Conservation and Recovery Act and Proposed
Subtitle C Regulations (1976 -1980)
On October 21, 1976, Congress enacted the Resource Conservation and Recovery Act (Pub. L. 94-
580). Section 3001 of RCRA mandated that the EPA Administrator "promulgate regulations identifying
characteristics of hazardous waste, and listing particular hazardous wastes which shall be subject to the
provisions of this subtitle." Section 3004 required the Administrator to promulgate standards applicable to
owners and operators of hazardous waste treatment, storage, and disposal facilities. Congress did not explicitly
address the regulation of mining and mineral processing wastes, but Section 8002(f) instructed the EPA
Administrator to conduct:
..a detailed and comprehensive study on the adverse effects of solid wastes from active and
abandoned surface and underground mines on the environment, including, but not limited
to, the effects of such wastes on humans, water, air, health, welfare, and natural resources..."
This study requirement was based upon the Congressional recognition that mining wastes were
generated in larger quantities than any other type of solid waste, and that historical and, perhaps,
contemporary mining wastes management practices, could pose danger to human health and the environment.
Mandated study factors included sources and volumes of wastes generated, present and alternative disposal
practices, potential danger posed by surface runoff and fugitive dust emissions, the cost of waste management
alternatives, and the potential for use of discarded materials as secondary sources having mineral value. The
House report (No. 94-1491) accompanying the RCRA bill indicates that the focus of EPA's inquiry was to be
the environmental and technical adequacy of current waste management practices, with economic practicality
being a secondary consideration.
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A-2 Appendix A: History of the Mining Waste Exclusion
On December 18,1978, EPA proposed its regulations for managing hazardous wastes under Subtitle C
of RCRA (43 FR 58946). These proposed regulations introduced the "special wastes" concept. "Special waste"
referred to wastes that were generated in large volumes, were thought to pose less risk to human health and
the environment than other hazardous wastes, and for which the proposed technical requirements
implementing Subtitle C might not be appropriate. EPA identified mining wastes as one of six such "special
wastes" under the proposed regulations.1 EPA proposed to defer most of the RCRA Subtitle C requirements
for these special wastes until information could be gathered and assessed that would enable EPA to regulate
them with special standards.
In the fall of 1979, EPA completed a draft background document that outlined the development of
EPAs methodology for determining which materials qualified as "special wastes" (Introduction and Criteria
for Special TOiste, November 2,1979, EPA Docket # A-D1-SS0062). The background document presents the
eight criteria that were used to develop the original list of "special wastes" for the December 18,1978 proposed
Subtitle C regulations:
1. Limited information on waste characteristics;
2. Limited information on the degree of human health and environmental hazard posed
by disposal;
3. Limited information on waste disposal practices and alternatives;
4. Very large volumes and/or large number of facilities;
5. Limited movement of wastes from the point of generation;
6. Few, if any, documented damage cases;
7. Apparent technological difficulty in applying current Subpart D2 regulations to the
waste because of volumes involved at typical facilities; and
8. Potential high economic impact if current Subpart D regulations are imposed.
The background document states further that criteria 1, 2, 3, 4, and 7 were the driving forces in the
decision-making process for the 1978 proposed Subtitle C regulations, while the other criteria were met to
some degree for individual wastes.
EPA received many public comments on the proposed Subtitle C regulations. The background
document indicates that the Agency incorporated many of these comments, as well as its own continuing
analysis, when it revised the criteria used to designate "special wastes." The concluding section discussed the
four criteria that EPA, at that point, intended to use to evaluate petitions to designate a waste as a "special
waste:"
1. The waste is or is anticipated to be generated and disposed in large volumes. This
determination would be based on the national volume generated per year; the projected
volume of waste generated over the next decade; the volume of waste disposed at a typical
disposal facility, and extraneous siting restrictions on the generator.
2. The waste should be uniform, i.e., the waste exhibits the same characteristics whenever
disposed, and is amenable to being predominantly managed without being mixed with other
wastes.
1 The other five "special wastes" were cement kiln dust waste; utility waste; phosphate rock mining, benefication, and processing waste;
uranium mining waste; and gas and oil drilling muds and oil production brines.
2 40 CFR Part 250, Subpart D contained the proposed RCRA Section 3004 management standards (43 FR 59008). These
requirements are now found in final form at 40 CFR Parts 264-266).
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Appendix A: History of the Mining Waste Exclusion A-3
3. The waste must pose only a low potential hazard to human health and the environment. This
determination would be based on the class of hazard of the waste; the chemical composition
and physical characteristics of the waste; results of the application of 40 CFR 250 Subpart A
[now 40 CFR Part 261] procedures for determining hazardous characteristics and other
available testing information (although ignitable, corrosive, or reactive wastes would be
acceptable as special wastes at the discretion of the Administrator); and information on
documented past damage cases.
4. Due to lack of information on current treatment, storage, and disposal practices and
alternatives, the Agency would be unable to propose standards for control of the waste.3
Using the revised list of four criteria, the Agency considered expanding the list of six "special wastes"
in the 1978 proposed Subtitle C regulations to a total of eleven:
1. Cement kiln dust waste;
2. Utility waste;
3. Phosphate mining, beneficiation, and processing waste;
4. Uranium mining waste;
5. Vfestes from the extraction, beneficiation, and processing of ores and minerals other than
phosphate rock and uranium ore;
6. Gas, oil, and geothermal drilling and production wastes;
7. Shale oil industry wastes;
8. Red muds [from bauxite refining];
9. Black muds [from bauxite refining];
10. Coal mining waste; and
11. Dredge spoils.
Though the special waste category was never promulgated, it is clear that EPA was responsible for
amplifying the original study requirement under RCRA 8002(f) into a'regulatory concept, that the Agency had
several specific criteria (principally low hazard, high volume, and infeasibility of Subtitle C technical
requirements) that it employed to evaluate potential special wastes, and that the group of wastes that might
have received the temporary exemption from full Subtitle C regulation was to be both finite and relatively
small.
3. Final Subtitle C Regulations and the Solid Waste Disposal Act Amendments
of 1980, including the Bevill Amendment (1980)
Throughout 1980, Congress was conducting hearings to substantially amend RCRA. On February 20,
1980, Rep. Thomas Bevill (AL) offered an amendment which, among other things, amended section 3001 to
temporarily exempt three categories of waste from Subtitle C regulation:
1. Fly ash waste, bottom ash waste, slag waste, and flue gas emission control waste generated
primarily from the combustion of coal or other fossil fuels;
2. Solid waste from the extraction, beneficiation, and processing of ores and minerals, including
phosphate rock and uranium ore; and
3. Cement kiln dust waste.
EPA also considered and rejected a number of criteria not included in the original list, including: adequacy of current waste
management practices, and resource recovery potential.
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A-4 Appendix A: History of the Mining Waste Exclusion
These wastes were to remain exempt from Subtitle C regulation until completion of the studies
required under Sections 8002(f) and 8002(n)(p), the latter of which was to be added to RCRA (these sections
are discussed below).
From his statements ;fore the Committee on Interstate and Foreign Commerce, it is apparent that
Rep. Bevill offered his amen. ent primarily to prevent regulatory disincentives for the development of the
nation's coal resources. Rep. Bevill stated that "the House [would] not allow EPA to take steps that will
discourage the use of coal." Rep. Bevill noted that EPA "has very little information on the composition,
characteristics, and degree of hazard posed by these [i.e., coal] wastes" and that the Agency believed that any
potential hazards presented by the materials are relatively low.
Rep. Bevill also claimed that existing Federal and State regulation would sufficiently regulate wastes
from the combustion of coal and other fossil fuels while EPA was undertaking the required studies. During
the hearing, several other representatives spoke in favor of the Bevill Amendment, specifically concerning
refuse-derived fuel (Rep. Horton-NY), fly ash and slag from coal (Rep. Findley-EL), oil and gas muds and
brines (Rep. Moffett-CT), and large volume coal wastes (Rep. Rahall-WV; Rep. Staggers-WV). Rep. Florio
(NJ) submitted for the record results of EPA studies that documented the known health risks associated with
radioactive uranium and phosphate wastes.
The discussion of mining wastes as a part of the Bevill Amendment was limited to brief comments
by Rep. Williams (MT), who stated that wastes from mineral production should not be subject to Subtitle C
regulation at that time. As an example of the limited potential hazard of these wastes, Rep. Williams
paraphrased a National Academy of Sciences study, stating that slag waste generated by the smelting of copper
...is basically inert and weathers slowly. The slag produced 2,500 years ago at King
Solomon's mines north of Eliat, Israel, has not changed perceptibly over time.
Rep. Williams then continued
Should wastes such as smelting slag be subject to stringent regulations at this time? I think not-not
until a thorough study is conducted by the responsible agency which clearly proves the need for
additional regulation. [Emphasis added.]
Based on Rep. Bevill's comments, it is apparent that the fundamental purpose of the amendment was
to limit the impact of Subtitle C regulation on the coal industry (the Senate version of this bill, however,
emphasized oil and gas field production wastes), at a time when the nation and the Congress were extremely
concerned about energy self-sufficiency. Although the Bevill Amendment, as read into the record during the
hearing, explicitly refers to mineral processing wastes, Rep. Bevill did not mention these wastes or respond
to Rep. Williams' statements.
Almost all of the major components of the Bevill Amendment were originally conceived by EPA.
The Bevill Amendment made the Agency's planned activities, as expressed in the 1978 proposed Subtitle C
regulations and the 1979 "Special Waste" background document, statutory requirements. In fact, with very few
exceptions, all of the specific provisions of the Bevill Amendment were lifted (often verbatim) from EPA
rulemakings and related documents.
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Appendix A: History of the Mining Waste Exclusion A-5
Furthermore, it is clear from the legislative history that the Bevill Amendment was designed to defer
regulation of those wastes which EPA had defined as special wastes. Congressman Bevill referred specifically
to EPA's 1978 special waste proposal in his explanation of the amendment, noting that EPA had asserted
it did not have data on the effectiveness of current or potential waste management technologies or
the technical or economic practicability of imposing its proposed regulations. In the same [12/18/78]
announcement, EPA also stated that it believed that any potential hazards presented by the materials
are relatively low.
126 Cong. Rec. 3361 (1980). Other Congressmen also referred to the Bevill wastes in terms of the EPA
"special waste" concept. Congressmen Santini, Staggers, and Findley all supported the amendment on the basis
that it would defer regulation of "special wastes" until EPA had completed the required study. Id. at 3348,
3349,3363,3365. Congressman Williams of Montana, in explaining why smelting slag should be studied (see
above), noted that the Bevill Amendment "would direct [EPA] to evaluate certain high volume, low toxicitv
wastes so as to assure a reasoned set of regulations by which to manage these wastes." Id. at 3364. Clearly,
the discussions on the floor of the House imply Congressional intent to incorporate the "special waste" concept
into the Bevill Amendment definitions of excluded wastes. (See also 852 F.2d at 1327).
On May 19, 1980, EPA promulgated final regulations under Subtitle C of RCRA which addressed,
among other things, "solid waste from the extraction, beneficiation, and processing of ores and minerals" (45
FR 33066). In promulgating these regulations, EPA decided to withdraw rather than finalize the "special
waste" category. The Agency's stated basis for this decision was twofold:
1. The thresholds for the (EP) extraction procedure toxicity and corrosivity characteris-
tics tests (which are used to identify hazardous wastes subject to Subtitle C regulation)
had been significantly relaxed. As a result, the number of wastes in general, and
"special wastes" in particular, that would be potentially subject to Subtitle C regulation
was greatly reduced.
2. The Agency had incorporated more flexibility, through phasing and standard-setting,
in Parts 264 and 265 (which contain the regulations for permitted and interim status
owners/operators of hazardous waste facilities). Thus, a RCRA permit writer had the
ability to take into account site-specific environmental characteristics and management
practices (i.e., "special waste" study factors) in establishing permit requirements.
As a result, the Agency concluded that these changes "accomplish the objectives of, and eliminate the need
for, a special solid waste category." When EPA eliminated the "special waste" concept, it was aware of
Congress' intention to exempt mining and mineral processing and other proposed "special" wastes from
Subtitle C regulation because passage of the Solid Waste Disposal Act Amendments of 1980 (including the
Bevill Amendment) was expected (Senate and House versions had been passed on June 4, 1979 and
February 20, 1980, respectively).
On October 12,1980, Congress enacted the Solid Waste Disposal Act Amendments of 1980 (Pub. L.
96-482), which added section 3001(b)(3)(A)(ii) (the Bevill Amendment) to RCRA. This section temporarily
prohibits EPA from regulating, among other wastes, "solid waste from the extraction, beneficiation, and
processing of ores and minerals, including phosphate rock and overburden from the mining of uranium ore"
as hazardous waste under Subtitle C of RCRA until at least six months after EPA completes and submits to
Congress the studies required by Section 8002(f), and by Section 8002(p), which was also added to RCRA by
the 1980 amendments. Section 8002(p) required the Administrator to study the adverse effects on human
health and the environment, if any, of the waste from the disposal and utilization of "solid waste from the
extraction, beneficiation, and processing of ores and minerals, including phosphate rock and overburden from
the mining of uranium ores," and submit a Report to Congress on its findings by October, 1983. The 1980
amendments also added section 3001(b)(3)(C), which requires the Administrator to make a regulatory
determination, within six months of the completion of the section 8002 studies, whether to regulate the studied
wastes under Subtitle C of RCRA
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A-6 Appendix A: History of the Mining Waste Exclusion
On November 19,1980, EPA published an interim final amendment to its hazardous waste regulations
to reflect this mining waste exclusion (45 FR 76618). The regulatory language incorporating the exclusion was
identical to the statutory language, except EPA added the phrase "including coal." In the preamble to the
amended regulation, however, EPA tentatively interpreted the exclusion to include "solid waste from the
exploration, mining, milling, smelting, and refining of ores and minerals." The preamble made it clear that
the Agency was interpreting the scope of the exclusions very broadly within the context of the mining industry,
and that, over the next 90 days, EPA intended to review the legislative history of the Bevill Amendment and
the public comments received in response to the interpretation. The preamble indicated that based on this
review, EPA would probably narrow the scope of the exclusion.
4. Litigation, the Hazardous and Solid Waste Amendments of 1984, and
Bevill Exclusion Reinterpretations (1981 -1988)
As noted above, the Solid >toste Disposal Act Amendments of 1980 amended section 3001 to require
the EPA Administrator to make a regulatory determination regarding the wastes temporarily excluded from
Subtitle C regulation within six months of submitting the required Report to Congress. EPA was required
to submit the Report to Congress by October, 1983. In 1984, the Concerned Citizens of Adamstown and the
Environmental Defense Fund sued EPA for failing to complete the section 8002 studies and the regulatory
determination by the statutory deadlines (Concerned Citizens of Adamstown v. EPA, No. 84-3041, D.D.C,
August 21,1985). EPA explained to the District Court for the District of Columbia that the Agency planned
to propose to "reinterpret" the scope of the mining waste exclusion so that it would encompass fewer wastes.
Therefore, EPA suggested two schedules to the court: one for completing the section 8002 studies and
submitting the Report to Congress, and one for proposing and taking final action on the reinterpretation. On
August 21, 1985, the court ordered EPA to meet these two schedules; first, the Agency was to complete the
section 8002 studies and Report to Congress by December 31, 1985, and to publish the regulatory
determination by June 30, 1986; and second, EPA was to propose to reinterpret the Bevill exclusion and
subsequently, to take final action on the proposed reinterpretation by September 30,1986.
EPA submitted the Report to Congress on December 31,1985. The Report to Congress provided
information on sources and volumes of waste, disposal and utilization practices, potential danger to human
health and the environment from mining practices, and evidence of damages. EPA focused on the mining
industry segments that produced and/or concentrated metallic ores, phosphate rock, or asbestos.
On July 3,1986, EPA issued its regulatory determination for the mining wastes covered by the Report
to Congress (51 FR 244%). The regulatory determination concluded that Subtitle C regulation of the wastes
studied in the Report to Congress (i.e., extraction and beneficiation wastes) was not warranted at that time.
This conclusion was based on EPAs belief that aspects of the Subtitle C standards were likely to be
environmentally unnecessary, technically infeasible, or economically impractical when applied to mining waste.
EPA announced its intention to develop a program for mining waste under Subtitle D of RCRA.
The Jury 3, 1986 regulatory determination was subsequently challenged in court (Environmental
Defense Fund v. EPA, 852 F.2d 1309 (D.C Cir. 1988)). The Court of Appeals upheld EPAs regulatory
determination for extraction and beneficiation wastes.
In the interim, Congress enacted the Hazardous and Solid V&ste Amendments to RCRA in 1984.
These amendments added new requirements applicable to owners and operators of facilities that treat, store,
or dispose hazardous waste, and included minimum technical standards for the design, construction, and
operation of waste management units, land disposal restrictions, and corrective action requirements for
continuing releases. In developing these new requirements, Congress considered their feasibility with respect
to and potential impact on the management of certain categories of wastes. This concern was embodied in
what was to become Section 3004(x) of RCRA, the so-called "Simpson Amendment," which allowed the EPA
Administrator to modify the Subtitle C technical standards for managing mining wastes, utility waste, and
cement kiln dust waste, as long as protection of human health and the environment was assured.
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Appendix A: History of the Mining Waste Exclusion A-7
In the floor debate on the Simpson Amendment, the Senate considered remarks concerning the types
of wastes that would be eligible for the special status conferred by the amendment. Sen. Jennings Randolph
(WV) read into the record the description of mining wastes that was contained in the committee report on
the HSWA amendments. In this report, "solid wastes from mining and mineral beneficiation and processing"
are described as "primarily waste rock from the extraction process, and crushed rock, commonly called
tailings..." The report continues by stating
[t]he 1980 amendments covered wastes from the initial stages of mineral processing, where
concentrations of minerals of value are greatly increased through physical means, before
applying secondary processes such as pvrometallurgical or electrolytic methods. Smelter slag
might also be included... These wastes were considered "special wastes' under the 1978
proposed regulations as being of large volume and relatively low hazard. [Emphasis added.]
The remaining discussion in the excerpt from the committee report focuses on the potential difficulties of
managing the huge volumes of waste rock and tailings associated with mineral exploitation under the new
minimum technology standards under debate.
Thus, although the Congress explicitly considered the special study wastes in crafting the provisions
of HSWA, there is nothing in either the amendments themselves or in the legislative record supporting them
to suggest that Congress construed the term "mineral processing" broadly, Le., to include wastes that are not
"special wastes."
In keeping with its agreement in theAdamstown case, on October 2,1985, EPA proposed to narrow
the scope of the Bevill exclusion (50 FR 40292). In preparing the proposed mining waste exclusion, EPA
implicitly applied the "high volume, low hazard, special waste" concept from EPAs 1978 proposed hazardous
waste regulations. The proposed rulemaking would have eliminated from the mining waste exclusion most
wastes from the processing of ores and minerals; EPA proposed to retain bauxite refining muds,
phosphogypsum from phosphoric acid plants, and slag from primary metal smelters and phosphorus reduction
facilities within the Bevill exclusion. In the preamble, EPA stated that Congressional intent supported the
Agency's special waste concept The proposed rule did not, however, outline the criteria that EPA used to
determine high volume or low hazard.
In response to the proposed reinterpretation, many commenters "nominated" additional wastes that
they believed fit the "special waste" criteria, and therefore should also be excluded from Subtitle C regulation
as "processing wastes." Because EPA had not explicitly defined the terms "high volume" or low hazard" in the
October 2, 1985 proposal, the Agency was unable to determine the regulatory status of these nominated
wastes. EPA could not infer definitions for these terms based upon the four wastes listed in the proposal as
meeting the "special waste" criteria. The public comments on the proposal and the Agency's analysis indicated
that the proposed reinterpretation could not be finalized because it did not set out "practically applicable"
criteria for distinguishing "processing" (Le., high volume, low hazard ore and mineral processing residuals) from
non-processing wastes (i.e., non-excluded) wastes. Moreover, the Agency was unsure whether such criteria
could be developed. Therefore, faced with the court-ordered deadline for final Agency action inAdamstawn,
EPA withdrew the proposal on October 9,1986 (51 FR 36233). As a consequence, the interpretation of the
mining waste exclusion established in the November 19,1980 rulemaking notice remained in effect.
The Agency's decision to withdraw its proposed reinterpretation of the mining waste exclusion was
subsequently challenged in court (Environmental Defense Rind v. EPA, 852 F.2d 1316 (D. C. Cir. 1988), cert.
denied 109 S. Ct. 1120 (1989) (EDF v. EPA)). In this case, the petitioners contended, and the Court of
Appeals agreed, that EPA's withdrawal of its proposed reinterpretation of the Bevill Amendment was arbitrary
and capricious because it reaffirmed an "impermissibty over-broad interpretation" of the Bevill Amendment
EDF v. EPA, 852 F.2d at 1326.
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A-8 Appendix A: History of the Mining Waste Exclusion
In reaching this decision, the Court found that the words "waste from ... processing of ores and
minerals" do not convey a self-evident, accepted meaning. Id. at 1327. Therefore, the Court reviewed the
structure and the legislative history of the Bevill Amendment to ascertain the intent of Congress. The Court
found that "[t]he structure of the Bevill Amendment suggests that the term 'solid waste from the . . .
processing of ores and minerals' should be interpreted in a manner consistent with the concept of large volume
wastes." Id. The Court also decided that "[t]he legislative history of the Bevill Amendment establishes that
the key to understanding Congress's intent is the concept of 'special waste' articulated in the regulations
proposed by EPA on December 18, 1978 following the enactment of RCRA." Id. See 43 FR 58911 (1978)
and 50 FR 40293 (1985).
In explaining this decision, the Court cited statements made by members of Congress during the
legislative consideration of the exclusion and the description of the provision in the Conference Report
accompanying the legislation. Based on these indications of Congressional intent, the court concluded that
it is clear that Congress did not intend the mining waste exclusion to encompass all wastes
from primary smelting and refining. On the contrary, Congress intended the term
"processing" in the Bevill Amendment to include only those wastes from processing ores or
minerals that meet the "special waste" criteria, that is, "high volume, low hazard" wastes. 852
F.2d at 1328-29.
Thus, when the Agency withdrew its October 2,1985, proposed reinterpretation of the mining waste exclusion,
which was based on implicit "special waste* criteria, EPA by default reverted to its November 19, 1980,
interpretation of the exclusion, which did not distinguish between high volume, low hazard processing wastes
and other processing wastes. As a consequence, the number of temporarily excluded processing wastes
remained very large. The Court ruled that this result was inconsistent with Congressional intent Therefore,
the Court ordered EPA to propose, by October 15,1988, a specific list of mineral processing wastes that meet
the criteria of high volume and low hazard, and thus remain temporarily excluded from Subtitle C regulation.
852 F.2d at 1331.
5. Final Reinterpretation of the Mining Waste Exclusion (1988-1990)
In compliance with this Court decision, on October 20,1988 EPA published a proposal to further
define the scope of Section 3001(b)(3)(A)(ii) of RCRA. (See 53 FR 41288.) In the October 20, 1988
proposal, EPA presented a criterion for defining mineral processing wastes and a two-part criterion for
identifying which mineral processing wastes are high volume; however, the Agency proposed to defer judgment
on the hazard posed by high volume mineral processing wastes until preparation of a required Report to
Congress. The Agency also applied the processing and volume criteria to its available data on mineral
processing wastes, and identified 15 wastes which it believed met the criteria, and which the Agency therefore
proposed to retain within the exclusion and study for the Report to Congress:
1. Slag from primary copper smelting
2. Process wastewater from primary copper smelting/refining
3. Slowdown from acid plants at primary copper smelters
4. Bleed electrolyte from primary copper refining
5. Slag from primary lead smelting
6. Slowdown from acid plants at primary zinc smelters
7. Process wastewater from primary zinc smelting/refining
8. Red and brown muds from bauxite refining
9. Phosphogypsum from phosphoric acid production
10. Slag from elemental phosphorus production
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Appendix A: History of the Mining Waste Exclusion A-9
11. Iron blast furnace slag
12. Air pollution control dust/sludge from iron blast furnaces
13. Waste acids from titanium dioxide production
14. Air pollution control dust from lime kilns
15. Slag from roasting/leaching of chromite ore.
Based on comments received on the October 20,1988 NPRM and further analysis, EPA decided that
significant changes in the proposal were necessary before a final rule establishing the boundaries of the Bevill
exclusion for mineral processing wastes could be promulgated. Accordingly, on April 17, 1989, the Agency
published a revised proposed rule that contained a modified high volume criterion, clarifications to the
definition of mineral processing, and for the first time, an explicit low hazard criterion. As stated in the April
notice, EPA believed that such a criterion is required in order to identify those mineral processing wastes that
are clearly not low hazard and, therefore, not "special wastes" even if they are high volume.
In the April NPRM, the Agency also proposed to remove from the Bevill exclusion all but 39 mineral
processing wastes, many of which were "nominated" in public comment on the October NPRM. Of these 39,
six wastes were believed at that time to satisfy all of the "special waste" criteria described in the proposal:
1. Slag from primary copper smelting
2. Slag from primary lead smelting
3. Red and brown muds from bauxite refining
4. Phosphogypsum from phosphoric acid production
5. Slag from elemental phosphorus production
6. Furnace scrubber blowdown from elemental phosphorus production.
The other 33 wastes were proposed to be conditionally retained within the exclusion, because they
are mineral processing wastes that the Agency believed satisfied the volume criterion articulated in the
proposal but for which the Agency did not have adequate data to evaluate compliance with the proposal's new
hazard criterion. Thus, the following 33 wastes were judged, based in many cases upon information submitted
in public comment, to have generation rates that might exceed 50,000 metric tons per year per facility, and
therefore, be potentially eligible for continued exclusion under Bevill:
1. Barren filtrate from primary beryllium processing
2. Raffinate from primary beryllium processing
3. Bertrandite thickener sludge from primary beryllium processing
4. Process wastewater from primary cerium processing
5. Ammonium nitrate process solution from primary lanthanide processing
6. Roast/leach ore residue from primary chrome ore processing
7. Gasifier ash from coal gasification
8. Cooling tower blowdown from coal gasification
9. Process wastewater from coal gasification
10. Bleed electrolyte from primary copper refining
11. Process wastewater from primary copper smelting/refining
12. Slag tailings from primary copper smelting
13. Calcium sulfate wastewater treatment plant sludge from primary copper smelting/refining
14. Furnace off-gas solids from elemental phosphorus production
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A-10 Appendix A: History of the Mining Waste Exclusion
15. Process wastewater from elemental phosphorus production
16. Fluorogypsum from hydrofluoric acid production
17. Air pollution control dust/sludge from iron blast furnaces
18. Iron blast furnace slag
19. Process wastewater from primary lead smelting/rr "ning
20. Air pollution control scrubber wastewater from lightweight aggregate production
21. V&stewater treatment sludge/solids from lightweight aggregate production
22. Process wastewater from primary magnesium processing by the anhydrous process
23. Process wastewater from primary selenium processing
24. Process wastewater from phosphoric acid production
25. Wistes from trona ore processing
26. Basic oxygen furnace slag from carbon steel production
27. Leach liquor from primary titanium processing
28. Sulfate processing waste acids from titanium dioxide production
29. Sulfate processing waste solids from titanium dioxide production
30. Chloride processing waste acids from titanium and titanium dioxide production
31. Chloride processing waste solids from titanium and titanium dioxide production
32. Slowdown from acid plants at primary zinc smelters
33. Process wastewater from primary zinc smelting/refining.
All other waste streams from mineral processing were proposed to be removed from the exclusion. Most of
the remaining streams were low volume; three high volume wastes were proposed for removal on the basis
of hazard: acid plant/scrubber blowdown from the primary copper, lead, and tin sectors.
On September 1, 1989 (see 54 FR 36592), EPA provided the final Bevill exclusion criteria. The
September 1 rulemaking also finalized the Bevill status of five mineral processing waste streams. EPA
temporarily retained these wastes within the Bevill exclusion for study in the July 1990 Report to Congress:
1. Slag from primary copper processing
2. Slag from primary lead processing
3. Red and brown muds from bauxite processing
4. Phosphogypsum from phosphoric acid production
5. Slag from elemental phosphorus production.
In addition, the Agency modified the list of mineral processing wastes proposed for conditional
retention in April 1989. In the September 1 rulemaking, the Agency conditionally retained 20 mineral
processing wastes within the Bevill exclusion:
1. Roast/leach ore residue from primary chromite production
2. Gasifier ash from coal gasification
3. Process wastewater from coal gasification
4. Calcium sulfate wastewater treatment plant sludge from primary copper processing
5. Slag tailings from primary copper processing
6. Furnace off-gas solids from elemental phosphorus production
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Appendix A: History of the Mining Waste Exclusion A-11
7. Fluorogypsum from hydrofluoric acid production
8. Process wastewater from hydrofluoric acid production
9. Air pollution control dust/sludge from iron blast furnaces
10. Iron blast furnace slag
11. Process wastewater from primary lead production
12. Air pollution control dust/sludge from lightweight aggregate production
13. Process wastewater from primary magnesium processing by the anhydrous process
14. Process wastewater from phosphoric acid production
15. Basic oxygen furnace and open hearth furnace air pollution control dust/sludge from carbon
steel production
16. Basic oxygen furnace and open hearth furnace slag from carbon steel production
17. Sulfate process waste acids from titanium dioxide production
18. Sulfate process waste solids from titanium dioxide production
19. Chloride process waste solids from titanium tetrachloride production
20. Slag from primary zinc processing.
All other mineral processing wastes that were not conditionally retained were permanently removed
from the Bevill exclusion as of the effective date of the September 1, 1989 rule (March 1, 1990 in non-
authorized states), subjecting these wastes to RCRA Subtitle C regulation if they are solid wastes and exhibit
one or more of the characteristics of hazardous waste as defined in 40 CFR Part 261.
On September 25,1989 (54 FR 39298), EPA reevaluated the status of the 20 conditionally retained
wastes. Applying the high volume and low hazard criteria contained in the September 1,1989 final rule, the
Agency proposed to permanently remove seven mineral processing wastes from the Bevill exclusion and retain
13 other mineral processing wastes within the exclusion for study in the Report to Congress.
On January 23,1990, a final rule established the status of the 20 mineral processing wastes which were
proposed either for removal from or retention in the Bevill exclusion in the September 25, 1989 notice of
proposed rulemaking (NPRM); fifteen of these wastes were retained in and five wastes were removed from
the exclusion by this notice. In addition, the rule contained technical corrections to the September 1, 1989
final rule. Furthermore, the January final rule promulgated a clarification to the definition of "designated
facility" that the Agency proposed on September 25,1989.
The January final rule completed EPAs rulemaking process regarding the RCRA status of mineral
processing wastes until the completion of the required Report to Congress and Regulatory Determination.
In establishing the final Bevill status for these 20 mineral processing wastes, the Agency considered
information presented in public comment on the September 25 proposal together with additional analysis of
previously collected EPA industry survey and field data and, where appropriate, modified the decisions made
in the September 25 proposal.
As in the September 25 proposal, the Agency evaluated the 20 mineral processing wastes by applying
the high volume and low hazard criteria contained in the September 1, 1989 final rule, using a three-step
process. First, the Agency applied the high volume criterion to the available waste generation data. For each
waste, the Agency obtained facility-specific annual waste generation rates for the period 1983-1988 and used
the highest average annual facility-level generation rate in calculating the sector-wide average. Mineral
processing wastes generated above the volume criterion thresholds (an average rate of 45,000 metric tons per
facility for non-liquid wastes, and 1,000,000 metric tons for liquid wastes) passed the high volume criterion.
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A-12 Appendix A: History of the Mining Waste Exclusion
In the second step, the Agency evaluated each of the 20 wastes with respect to the low hazard
criterion using the relevant waste characteristics. EPA considered a waste to pose a low hazard only if the
waste passed both a toxicity test (Method 1312) and a pH test.
The third step involved consolidating the results from the first two steps to determine the appropriate
Bevill status of the 20 conditionally retained mineral processing wastes. Applying these criteria, the Agency
removed the Bevill exclusion for the following five mineral processing wastes:
1. Furnace off-gas solids from elemental phosphorus production
2. Process wastewater from primary lead processing
3. Air pollution control dust/sludge from lightweight aggregate production
4. Sulfate process waste acids from titanium dioxide production
5. Sulfate process waste solids from titanium dioxide production.
The following 15 mineral processing wastes were retained within the exclusion (in addition to the five
already retained in the September 1 rule), pending preparation of this Report to Congress and the subsequent
Regulatory Determination:
1. Treated residue from roasting/leaching of chrome ore
2. Gasifier ash from coal gasification
3. Process wastewater from coal gasification
4. Calcium sulfate wastewater treatment plant sludge from primary copper processing
5. Slag tailings from primary copper processing
6. Fluorogypsum from hydrofluoric acid production
7. Process wastewater from hydrofluoric acid production
8. Air pollution control dust/sludge from iron blast furnaces
9. Iron blast furnace slag
10. Process wastewater from primary magnesium production by the anhydrous process
11. Process wastewater from phosphoric acid production
12. Basic oxygen furnace and open hearth furnace air pollution control dust/sludge from carbon
steel production
13. Basic oxygen furnace and open hearth furnace slag from carbon steel production
14. Chloride process waste solids from titanium tetrachloride production
15. Slag from primary zinc processing.
The January rale also contained technical corrections to the September 1, 1989 final rale. The
Agency's review of the final rule, as well as public comments, revealed slight differences between portions of
the regulatory language and the corresponding discussion in the preamble. As a result, the January rule
included minor editorial changes to the language of the September 1 final rule.
The January rule established the boundaries of the temporary exclusion from hazardous waste
regulations for mineral processing wastes provided by RCRA Section 3001(b)(3)(A)(ii). All 20 mineral
processing wastes for which the Bevill exclusion has been retained have been subject to detailed study in this
Report to Congress.
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Appendix B
EPA Data Collection Activities
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Appendix B-1
Description of the 1989 National Survey of
Solid Wastes from Mineral Processing
Facilities (SWMPF Survey)
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Appendix B-1
Description of the 1989 National Survey
of Solid Wastes from Mineral Processing Facilities
(SWMPF Survey)
In order to be fully responsive to the individual study factors provided in Section 8002(p) of RCRA,
EPA needed to obtain information that specificallv pertained to the facilities, processes, and management
practices that are associated with the ore and mineral processing wastes that are covered by the Mining Waste
Exclusion. Accordingly, in February of 1989, EPA administered a written questionnaire to the operators of
all facilities that, to the Agency's knowledge, generated one or more of the ore and mineral processing waste
streams that the Agency was, at that time, considering retaining within the Exclusion. The survey consisted
of approximately 300 questions, and was distributed to the operators of about 200 mineral processing facilities.
EPA requested that a person who was knowledgeable about the waste management practices utilized
at the particular facility provide written answers to the questions in the survey, and submit these responses
to the Agency. EPA then analyzed these data, and has used them to respond to the requirements of RCRA
Section 8002(p) in preparing this report. In particular, the data collected allowed the Agency to address the
sources and volumes of the excluded wastes (study factor 1), current and alternative waste management
practices (study factors 2 and 5), costs of alternative waste management practices (study factor 6), and potential
danger to human health and the environment (study factor 3).
Data necessary to evaluate documented cases of danger (study factor 4), current and potential
utilization of ore and mineral products (study factor 8), and potential impacts of waste management
alternatives on the use of mineral resources (study factor 7) were developed through other sources (primarily
intensive literature reviews, state contacts, and the U.S. Bureau of Mines).
The questionnaire was divided into nine sections. A description of each section, the types of
information that it was designed to elicit, and the uses of the information obtained thereby is presented below:
• Section 1 - General facility information. This section requested information on the
owner, operator, location, and operating status of the facility. In addition, this section
contained questions that addressed the proximity of the facility to sensitive environ-
ments. Responses to these questions allowed EPA to verify important background data,
and enabled the Agency to perform screening-level analyses of potential risk to human
health and the environment, as well as to collect financial data needed for economic
impact assessment
• Section 2 - Processing units that generate a special waste. The questions in this section
pertained to the specific points in the production process at which the special wastes
were and are generated. The emphasis of the section was on gaining knowledge of how,
where, and why these materials are generated. Respondents were asked to describe all
on-site processes that generate each waste of concern. One duplicate set of questions
was provided in an appendix to the questionnaire.
• Section 3 - Processing units that receive a special waste Cor its residue"). This section
sought information on on-site operating units that utilized one or more special wastes
as feedstocks, and produced final or intermediate products (i.e., materials of value).
This information was also used to characterize current and alternative waste manage-
ment practices. In particular, this section enabled EPA to evaluate the extent to which
some of the special wastes are indeed handled as in-process feedstocks rather than
wastes, as a number of facility operators and industry trade associations have claimed.
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B-1-2 Appendix B-1: SWMPF Survey
Section 4 - Wastewater treatment plants that receive a special waste (or its residual.
The questions in this section pertained to the specific practices that were employed in
on-site wastewater treatment plants to manage special wastes. (These operations are
sufficiently different than other types of waste management units to justify addressing
them separately.) Questions pertained to capacity, treatment technologies employed,
residues generated, and the fate of each of these treatment residues. This information
was utilized to evaluate current, and especially, alternative waste management practices.
Section 5 - Surface impoundments that receive a special waste Cor its residue1). The
content and format of this section mirrored that of section 4, except that the questions
were specifically oriented toward the characteristics of surface impoundments, a major
waste management technology employed in the mineral processing industry. Once
again, the nature of surface impoundments differs significantly from other waste
management unit types; hence, for clarity, these units were addressed in their own
section.
Section 6 • Other waste management units that receive a special waste (or its residue').
This section contained a series of questions that pertained to all other specific
management practices that are applied to the special wastes and their treatment
residues. This information is vital to EPA's understanding of the extent to which
current industry practice is adequate to prevent releases of contaminants to the
environment In addition, EPA estimated the costs of these contemporary management
practices to provide a baseline against which the costs of regulatory alternatives are
compared. Again, an additional copy of some questions was provided in an appendix,
so that the respondents could clearly and unambiguously describe all waste management
units that handle a special waste and its residues.
Section 7 - Environmental monitoring near waste management units. This section
contained questions that addressed important environmental variables and any
environmental monitoring that facility operators are conducting. Responses were used
to assess actual and potential environmental contamination arising from the current
practices used to manage special wastes.
Section 8 - Wfrste management units not covered in sections 5 and 6. The questions in
this section were in some instances similar in content to those in sections 5 and 6, but
focused on any additional waste management units that do not receive or generate any
special wastes or residues of special wastes. This information is required to assess the
likelihood that documented or potential environmental contamination episodes are due
to the improper management of wastes that are outside of the scope of the Report to
Congress and to assess the potential need to conduct corrective action.
Section 9 - Follow-up information. This final section simply requested the name, title,
address, and telephone number of a person whom EPA could contact if clarification of
the information provided to the Agency by the respondent was required.
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Appendix B-2
Description of 1989 EPA Sampling and
Analysis Activities
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Appendix B-2
Description of 1989 EPA Sampling and
Analysis Activities
This appendix provides a summary of the EPA mineral processing waste sampling and analysis
activities conducted during 1989 in support of rulemaking activities and preparation of this report. It includes
brief descriptions of the background, objectives, and scope of the sampling effort, the methodology used to
select candidate facilities, and the facilities that EPA sampled. The results of the sampling effort as they relate
to the wastes covered by this report are presented in the supporting public docket (F-90-RMPA-FFFFF).
Background
Section 8002(p) of the Resource Conservation and Recovery Act (RCRA) requires EPA to study the
adverse effects on human health and the environment, if any, from the disposal and utilization of "solid waste
from the extraction, beneficiation, and processing of ores and minerals, including phosphate rock and
overburden from the mining of uranium ore," and submit a Report to Congress on its findings. Section 3001
of RCRA excludes these wastes from regulation under Subtitle C of RCRA, pending completion of the study
called for in section 8002(p). These provisions are collectively often referred to as "the Mining Waste
Exclusion." Since 1980, EPA has interpreted the language of Section 8002(p) to include "solid waste from the
exploration, mining, milling, smelting, and refining of ores and minerals" (45 FR 76618),
In response to the decision of the Court of Appeals in Environmental Defense Fund v. EPA. 852 F.2d
1316, D. C. Cir., 1988 (EDF v. EPA). EPA proposed (53 FR 41288, October 20, 1988) to narrow the scope
of the Mining Waste Exclusion such that only 15 specific mineral processing wastes would be addressed in the
study required by RCRA §8002(p); other mineral processing wastes were proposed to become subject to
RCRA Subtitle C regulations if they exhibit one or more characteristics of hazardous waste. The 15 wastes
proposed for study were distinguished from other mineral processing wastes based on the fact that they are
generated in large volumes.
Based on public comments on the proposal and additional analysis, EPA subsequently proposed that
mineral processing wastes to be studied be "low hazard" as well as "large volume." (See 54 FR 15316, April 17,
1989.) In the April proposal, EPA proposed to include six wastes within the scope of the §8002(p) study and
indicated that the Agency needed more data to determine whether 33 additional wastes that met the proposed
"high volume" criterion were also "low hazard" and, thus, would also be included in the study.
Objectives
The primary objective of collecting and analyzing mineral processing waste samples was to obtain the
knowledge of the physical and chemical characteristics of the wastes that was needed to aid in determining
which large volume wastes are "low hazard." The secondary objective was to provide information for use in
evaluating the Section 8002(p) study factors for the required Report to Congress.
Scope
The types of wastes covered by the sampling and analysis effort were determined based on the
Agency's April 17,1989 proposal noted above. Specifically, the types of wastes covered by the sampling effort
included: (1) the 33 types of waste proposed for conditional exclusion from RCRA Subtitle C requirements
pending collection of information needed to determine if they are "low hazard"; (2) the three large volume
wastes that the Agency proposed to remove from the exclusion because they were believed not to be "low
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B-2-2 Appendix B-2: EPA Sampling and Analysis Activities
hazard"; and (3) additional large volume wastes identified in public comments on the proposed rule. The 33
wastes proposed for conditional exclusion on April 17, 1989 were as follows:
• barren filtrate from primary beryllium processing;
• raffinate from primary beryllium processing;
• benrandite thickener sludge from primary beryllium processing;
• process wastewater from primary cerium processing;
• ammonium nitrate process solution from primary lanthanide processing;
• roastAeach ore residue from primary chrome ore processing;
• gasifier ash from coal gasification;
• cooling tower blowdown from coal gasification;
• process wastewater from coal gasification;
• bleed electrolyte from primary copper refining;
• process wastewater from primary copper smelting/refining;
• slag tailings from primary copper smelting;
• calcium sulfate wastewater treatment plant sludge from primary copper smelting/refining;
• furnace off-gas solids from elemental phosphorus production;
• process wastewater from elemental phosphorus production;
• fluorogypsum from hydrofluoric acid production;
• air pollution control dust/sludge from iron blast furnaces;
• iron blast furnace slag;
• process wastewater from primary lead smelting/refining;
• air pollution control scrubber wastewater from lightweight aggregate production;
• wastewater treatment sludge/solids from lightweight aggregate production;
• process wastewater from primary magnesium processing by the anhydrous process;
• process wastewater from primary selenium processing;
• process wastewater from phosphoric acid production;
• wastes from trona ore processing;
• basic oxygen furnace slag from carbon steel production;
• leach liquor from primary titanium processing;
• suifate processing waste acids from titanium dioxide production;
• sulfate processing waste solids from titanium dioxide production;
• chloride processing waste acids from titanium and titanium dioxide production;
• chloride processing waste solids from titanium and titanium dioxide production;
• blowdown from acid plants at primary zinc smelters; and
• process wastewater from primary zinc smelting/refining.
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Appendix B-2: EPA Sampling and Analysis Activities B-2-3
The 3 large volume wastes that EPA proposed to remove from the mining waste exclusion because
they are not low hazard" were:
• acid plant and scrubber blowdown from primary copper processing;
• acid plant blowdown from primary lead processing; and
• air pollution control scrubber blowdown from primary tin processing.
Additional large volume wastes identified in comments on the proposed rule and included in the
sampling effort were:
• basic oxygen furnace and open hearth furnace air pollution control dust/sludge from carbon
steel production;
• open hearth furnace slag from carbon steel production;
• process wastewater from hydrofluoric acid production, and
• sulfate leach residue from primary copper processing.
Samples of each of these 38 types of waste1 were collected at the point of waste generation from at
least two facilities (except for waste types that are only generated by a single facility) because this was the
minimum amount of data needed to implement the proposed "low hazard" criterion. In addition, EPA
sampled the following five wastes, for which the Agency proposed on April 17, 1989 to retain the exclusion,
where these wastes were generated at facilities that were visited for sampling of the 38 wastes listed above:
• slag from primary copper smelting;
• slag from primary lead smelting;
• phosphogypsum from phosphoric acid production;
• slag from elemental phosphorus production; and
• furnace scrubber blowdown from elemental phosphorus production.
One additional waste for which the Agency proposed to retain the mining waste exclusion, red and brown
muds from bauxite refining, was not sampled because sampling visits to the facilities that generate this waste
were not otherwise required.
In general, the wastes were also sampled "as managed" (e.g., after treatment or disposal) to provide
information that could be used in the assessment of potential danger to human health and the environment
for the Report to Congress.
Selection of Facilities for Sampling
Based on information provided by the U.S. Bureau of Mines, state agencies, and public comments
received on the October 20,1988 and April 17,1989 proposed rules, EPA developed a list of the facilities in
the United States that were thought to generate one or more of the 38 large volume mineral processing wastes
identified for sampling. This list of facilities defined the universe of facilities from which individual facilities
were selected for sampling.
1 No primary tin processing facilities were in operation at the time the sampling was conducted, so air pollution control scrubber
blowdown from primary tin processing was not sampled. In addition, basic oxygen furnace slag and open hearth furnace slag from carbon
steel production were subsequently combined and considered to be a single waste type, though both were sampled separately. As a result,
the number of mineral processing wastes discussed here as identified for sampling is 38 rather than 40.
-------
B-2-4 Appendix B-2: EPA Sampling and Analysis Activities
EPA selected facilities for sampling from this list using the following procedure:
Step 1. Select facilities for sampling that generate any of the 38 wastes that are generated by
only one or two facilities. This step resulted in the selection of 15 facilities in eight
commodity sectors2 that generate 18 types of waste that are generated by two or fewer
facilities. Three of the 15 selected facilities (in the copper sector) also provide for
collection of at least two samples of each of three additional waste types.3 Thus, this
step provides for sampling of 21 of the 38 wastes.
Step 2. Select facilities randomly from the ten commodity sectors4 that have three or more
facilities that generate one or more of the other 17 wastes, such that each of the 17
wastes can be sampled at two or more facilities. For each commodity sector, EPA
generated three random numbers (between 0 and 1) using a Lotus 1-2-3 random number
generator and multiplied each of the three numbers by the number of facilities- in the
commodity sector. The product of the first random number and the number of facilities
in the sector, rounded off to the next highest whole number, was the number of the first
facility chosen for sampling.5 The second number was the number of the second
facility chosen for sampling. If the first two facilities selected both generated all of the
wastes generated by the sector that needed to be sampled (exclusive of wastes covered
in step 1 above), then selection of facilities for sampling in the sector was complete.
If not, then a third (or additional) facility was selected in the same way until each waste
could be sampled at at least two facilities. This step resulted in the selection of 22
facilities for sampling.
Following completion of this site selection procedure, data from the "National Survey of \tostes from
Mineral Processing Facilities" became available that indicated that several facilities on the initial list of
facilities selected for sampling did not generate one or more of the wastes that EPA planned to sample at the
facility. In these cases, the next random number for the sector was used to select an alternate facility for
sampling. Similarly, telephone calls to selected facilities that EPA made to collect information needed to plan
the sampling visits sometimes led to the conclusion that a facility needed to be deleted from the sampling
frame. In these cases, the next random number for the sector also was used to select an alternate facility for
sampling.
Facilities Selected for Sampling
The 37 facilities that were selected for sampling based on the procedures described above are listed
in Exhibit B-2-1. Of these 37 facilities, only 27 facilities generate one or more wastes that are covered by this
report. These 27 facilities are identified with asterisks in Exhibit B-2-1.
2 Beryllium, cerium/laiuhanide, chrome ore, coal gasification, copper, magnesium, molybdenum, and titanium.
3' It is also the case that the two facilities selected for sampling of sulfate process wastes from titanium ore processing generate the
chloride process wastes that also needed to be sampled. However, these facilities do not use the predominant chloride process or
feedstocks, so additional facilities were selected for sampling.
4 Elemental phosphorus, hydrofluoric acid, iron/tteel, lead, copper, lightweight aggregate, phosphoric acid, soda ash, titanium, and zinc.
$ For example, if 0.44*7 is the first random number generated and there are 4 facilities in the commodity sector, the second facility
was the first facility selected for sampling [0.4467 x 4 » 1.7868, rounded up to the neareM whole number is 2].
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Appendix B-2: EPA Sampling and Analysis Activities B-2-5
Exhibit B-2-1
Mineral Processing Facilities Sampled By EPA
For The Report To Congress
Commodity Sector
Beryllium
Cerium/Lanthanides
Sodium Dichromate
Coal Gasification
Copper
Elemental Phosphorus
Hydrofluoric Acid
Iron/Steel
Lead
Lightweight Aggregate
Magnesium
Molybdenum
Phosphoric Acfd
Soda Ash
Titanium Tetrachtoride
Zinc
Facility
Brush Wellman Co., Delta, UT
Molycorp, Inc., Louviers, CO
Molycorp, Inc., York, PA
Occidental Chemical Corp., Castle Hayne, NC*
American Chrome and Chemical, Corpus Christi, TX*
Dakota Gasification, Beulah, ND*
ASARCO Inc., Hay den, AZ*
Kennecott Utah Copper, Bfngham Canyon, UT*
Magma Copper Co., San Manuel, AZ*
Cypress, Casa Grande, Casa Grande, AZ
FMC Corp, Pocatello, ID*
Stauffer Chemical, Mt. Pleasant, TN*
Allied-Signaf Corp, Geismar, LA*
Pennwalt Corp., Catvert City, KY*
Sharon Steel Corp., Sharon, PA*
USX, Lorain, OH*
USA, Fairless, PA*
USX, Braddock, PA*
Bethlehem Steel, Sparrows Point, MD*
ASARCO, East Hetena, MT*
ASAflCO, Glover, MO'
Doe Run Company, Hereu)an*um, MO
Northeast Solite Corp., Mount Marion, NY
Arkansas Lightweight Aggregate, W. Memphis, AR
Magnesium Corp. of America, Salt Lake City, UT"
Climax Molybdenum, Fort Madison, IA
IMC, Mulberry, FL*
CF Industries, Plant City, FL*
Stauffer Chemicals, Green River, WY
Tenneco, Green River, WY
du Pont, Pas« Chrtotian^MS*
du Pont, Edgemoor, DE*
Kemira, Savannah, GA*
SCM, Baltimore, MD*
Timet, Henderson, NV*
Zinc Corp. of America, Monaca, PA*
Zinc Corp. of America, Bartlesvill, OK
Indicates facilities included within the scope of the Report to Congress.
-------
Appendix B-3
List of Facilities With Documented Cases
of Damage from Mineral Processing Waste
-------
Appendix B-3
List of Facilities With Documented
Cases of Damage from Mineral Processing Waste
Alumina
Ormet, Burnside, LA
Coal Gasification
Dakota Gasification, Beulah, ND
Copper
ASARCO, El Paso, TX
ASARCO, Commencement Bay, Tacoma,
WA
Anaconda, MT
Valley Materials Corporation
(Midvale Slag), Midvale, UT
Ferrous Metals
LTV Steel, Aliquippa, PA
Hydrofluoric Acid
Allied-Signal, Geismar, LA
Lead
Doe Run, Boss, MO
ASARCO, Glover, MO
ASARCO, E. Helena, MT
ASARCO, El Paso, TX
Valley Materials Corporation
(Midvale Slag), Midvale, UT
Phosphoric Acid
Gardinier, East Tampa, FL
Seminole, Bartow, FL
Central Phosphates, Plant City, FL
Texasgulf, Aurora, NC
Arcadian, Geismar, LA
Agrico, Donaldsonville, LA
Nu-West, Caribou, ID
Zinc
Zinc Corporation of America
(Palmerton Zinc), Palmerton, PA
Zinc Corporation of America, DePue, IL
ASARCO, Columbus, OH
ASARCO, El Paso, TX
1 Facilities are listed under each sector for which there is a documented case of danger.
-------
Appendix B-4
Example of RCRA §3007 Data Request
-------
Office of
Solid Waste and Emergency Response
OMB # 2050-0092
Expires: 12/89
Name
Address
Dear Sir:
The U.S. Environmental Protection Agency (EPA) is gathering
data on selected mineral processing wastes. Currently, solid
wastes from mineral processing operations are excluded from
regulation under Subtitle C of the Resource Conservation and
Recovery Act (RCRA), as amended, [see 40 CFR 261.4(b)(7)]. On
July 29, 1988, the U.S. Court of Appeals for the District of
Columbia Circuit directed EPA to narrow the scope of this
exclusion and complete the Report to Congress required by Section
8002(p) of RCRA for the wastes that remain excluded under the
narrower scope. [Environmental Defense Fund v. EPA. 852 F. 2d
1316 (D.C. Cir. 1988)]. The data that EPA is gathering are
needed by the Agency to help determine which processing wastes
will remain within the exclusion and be studied in the Report to
Congress. In addition, the data will be used in preparation of
the Report to Congress.
As part of this data gathering effort, EPA recently mailed
your firm the "National Survey of Solid Wastes from Mineral
Processing Facilities" (OMB # 2050-0098). The survey is designed
primarily to collect information on the generation and management
of selected wastes at your processing facility. This
letter is intended to gather additional information — data on
waste characteristics.
EPA is requesting that you submit all existing data
collected since January 1, 1984 on the physical (e.g., solids
content or percent moisture, particle size) and chemical
composition (i.e., presence and concentration of elements and
compounds included in 40 CFR Part 264, Appendix IX),
radioactivity, and pH (if applicable) of any of the following
wastes generated at your processing facility:
• [slag, process wastewater, air pollution control dust/
sludge, etc.]
-------
- 2 -
Existing data from extraction-type tests is also requested. In
particular, the Agency is interested in the results of any
synthetic precipitation leach tests (met.-od 1312) and Extraction
Procedure (EP) toxicity tests (method 1310) that have been
performed (see "Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods," third edition, SW-846). However, the
Agency also requests data from any other extraction-type tests
that have been performed.
You are requested to submit hard copies of the appropriate
data within two weeks of receiving this letter. All data
submitted should clearly indicate the type of waste to which they
apply, the date the sample was collected, and the analytical
method(s) used.
In the event that you have few or none of the existing data
being requested, or you have reason to believe that the existing
data are not representative of the waste that you currently
generate, you may wish to voluntarily collect new data through
sampling and analysis. If you choose to collect new data, you
must notify the Agency of your intention to do so within two
weeks of receiving this letter. These new data must be developed
using the methods found in the third edition of "Test Methods for
Evaluating Solid Waste, Physical/Chemical Methods," SW-846. In
addition, the data must be received by the Agency no later than
60 calendar days after receipt of this letter.
We are requesting this information under authority of
Section 3007 of RCRA. Failure to respond to this information
request within the specified amount of time may lead to penalties
under Section 3008(a). In addition, information obtained under
RCRA Section 3007 must be made available to the public unless you
demonstrate to EPA that it is confidential. The treatment of
confidential business information is provided for by Section
3007(b) of RCRA and regulations contained in 40 CFR Part 2.
If you have any questions in response to this inquiry,
please contact Bob Hall at (202) 475-8814. We look forward to
your response.
Sincerely,
David Bussard
Acting Director
Waste Management Division
-------
Appendix B-5
List of Published Reports, Papers,
Abstracts, and Data
-------
Appendix B-5
List of Published Reports, Papers,
Abstracts, and Data
This bibliography contains many of the documents (e.g., journal articles, reports, surveys, trip reports,
and miscellaneous correspondence) which contributed to the Agency's understanding of the waste streams
under consideration. This is not a complete inventory of the documents cited in the report, and some of the
documents reported in this bibliography are not cited in the report. Documents which only contain
information on a single sector are organized by sector, in the same order as the chapters of the report.
Documents with information on more than one sector are located at the end of the bibliography under the
heading "Multisector Documents".
Alumina
1. Shiao, S J. and K. Akashi, "Phosphate Removal From Aqueous Solution From Activated Red Mud,"
Journal WPCF. Vol. 49, No. 2, February 1977, pp. 280-285.
2. Baseden, S. and D. Grey, "Environmental Study of the Disposal of Red Mud \\feste," Marine Pollution
Bulletin. Vol. 7, No. 1, January 1976, pp. 4-7.
3. Fuller, Robert D., Emily D.P. Nelson, and Curtis J. Richardson, "Reclamation of Red Mud (Bauxite
Residues) Using Alkaline-Tolerant Grasses with Organic Amendments,1' Journal of Environmental
Quality. Vol. 11, No. 3,1982, pp. 533-539.
4. Couillare, D., "Use of Red Mud, A Residue of Alumina Production by the Bayer Process, in Water
Treatment," The Science of the Total Environment. Vol. 25,1982, pp. 181-191.
5. "Kaiser Develops Red Mud Disposal System," Engineering and Mining Journal. June 1975, p. 140.
6. R.L.W. (only initials given), "Alcoa of Australia Has New Alumina Operations Ready for Market
Recovery," Engineering and Mining Journal. November 1983, pp. 77-81.
7. Parekh, B.K. and W.M. Goldberger, "Utilization of Bayer Process Muds: Problems and Possibilities,"
Proceedings of the Sixth Mineral Wfrste Utilization Symposium. Chicago, IL, May 2-3,1978, pp. 122-
132.
8. Fursman, Oliver C, James E. Mauser, M.O. Butler, and W.A. Stickney, Utilization of Red Mud
Residues From Alumina Production. RI 7454, Bureau of Mines, U.S. Department of the Interior,
1970.
9. V&gh, Arun S. and Willard R. Pinnock, "Occurrence of Scandium and Rare Earth Elements in
Jamaican Bauxite Waste," Economic Geology. 1987, pp. 757-761.
10. Thakur, R. and B.R. Sant, "Utilization of Red Mud," Journal of Scientific Industrial Research. August
1974, pp. 408-416.
11. Knight, J.C, Arun S. Vtegh, and W.A. Reid, The Mechanical Properties of Ceramics from Bauxite
Wwte," (Journal Unknown"). 1986, pp. 2179-2184.
12. Wfcrd, S.C, "Growth and Fertilizer Requirements of Annual Legumes on a Sandy Soil Amended With
Fine Residue From Bauxite Refining," Reclamation and Revegetation Research. Vol. 2, 1983,
pp. 177-190.
-------
B-5-2 Appendix B-5: List of Published Reports
13. Parekh, B.K. and W.M. Goldberger, Battelle, An Assessment of Technology for Possible Utilization
of Bayer Process Muds. EPA 600/2-76-301; Environmental Protection Technology Series, prepared
for Industrial Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency,
December 1976.
14. Thakur, R.S. and B.R. Sant, "Utilization of Red Mud: Pan II - Recovery of Alkali, Iron, Aluminum,
Titanium, and Other Constituents and Pollution Problems," Journal of Scientific and Industrial
Research. 1983, pp. 456-469.
15. Blank, H.R., "Red Mud from Alumina Plants as a Possible Source of Synthetic Aggregate," Journal
of Testing and Evaluation. September 1976, pp. 355-358.
16. Pincus, Aleads G., "Wastes from Processing of Aluminum Ores," Proceedings of the First Mineral
Waste Utilization Symposium. Chicago, IL, March 27-28,1968, pp. 40-49.
17. Shultz, Forrest G. and John S. Berber, "Hydrogen Sulfide Removal from Hot Producer Gas with
Sintered Absorbents," Journal of Air Pollution Control Association. 1970, pp. 93-96.
18. Friedrich, Vilem, "Production of Vanadium Slag from Bauxite Red Mud," Technical Digest. 1967, pp.
443-444.
19. Thakur, R.S. and B.R. Sant, "Utilization of Red Mud: Part I - Analysis and Utilization as Raw
Material for Absorbents, Building Materials, Catalysts, Fillers, Paints and Pigments," Journal of
Scientific and Industrial Research. Vol. 42, February 1983, pp. 87-108.
20. "Bauxite Waste Tests OK as Flocculant," Canadian Chemical Processing. March 1976, p. 26.
21. Whittaker, Colin W, W.H. Armiger, P.P. Chichflo, and W.M. Hoffman, "Brown Mud' from the
Aluminum Industry as a Soil Liming Material,* Soil Science Society Proceedings. 1955, pp. 288-292.
22. Guccione, Ugene, "'Red Mud,' A Solid Waste, Can Now be Converted to High-quality Steel,"
Engineering and Mining Journal. September 1971, pp. 136-138.
23. Parsons, Terry, Industrial Process Profiles for Environmental Use. Chapter 25: Primary Aluminum
Industry. EPA-600/2-T7-023y, Environmental Protection Technology Series, Industrial Environmental
Research Laboratory, ORD, U.S. Environmental Protection1 Agency, February 1977.
Coal Gasification
24. Chin, Kai C, John A. Cha, and Phool K. Lira, "A Novel Coupling-Dephenolization Scheme for Full-
Strength Coal-Conversion Wistewaters: Results of Wastewater Study and a Cost Analysis," Ind. Eng.
Chem. Process Des. Div.. VoL 24, No. 2,1985, pp. 339-343.
25. Strayer, Richard F. and Edward C Davis, "Reduced Sulfur in Ashes and Slags from the Gasification
of Coals: Availability for Chemical and Microbial Oxidation," Applied and Environmental
Microbiology. March 1983, pp. 743-747.
26. Portnoy, Kristine, "Who Wants a Coal Gasification Plant?" Chemical Engineering. April 11, 1988,
pp. 23-28.
27. Boegly, William J., Jr., Henry W. Wilson, Jr., Chester W. Francis, and E.C Davis, "Land Disposal of
Coal Gasification Residue," Journal of the Energy Division. Proceedings of the American Society of
Civil Engineers. Vol. 106, No. EY2, October 1980, pp. 179-187.
28. "Basin Electric Seeks Great Plains Profits Through Byproduct Sales," Electric Utility Week.
December 12,1988, p. 14.
29. "Great Plains Gasification Plant Profitable for Basin Electric," Electric Utility Week. July 10, 1989,
p. 10.
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Appendix B-5: List of Published Reports B-5-3
30. Bombaugh, Karl J. and William J. Rhodes, "Discharges from Coal Gasification Plants," Environmental
Science and Technology. Vol. 22, No. 12, 1988, pp. 1389-13%.
31. "Great Plains Seeks to Capitalize on Gasification Process By-products," Clean-Coal Svnfuels Letter.
November 18, 1988.
32. Fischer, Dennis D., Radian Corporation, Estimated Groundwater Restoration Costs Associated with
Commecial Underground Coal Gasification Operations. Tbpical Report. GRI 85/0256, prepared for
Gas Research Institute, December 17, 1985.
33. Castaldi, F.J. and S.L. Winton, Radian Corporation, Treatment System Design for Process
Wastewaters From Non-Tar Producing Coal Gasification Technology. Final Report (March 1983 -
June 19851. GRI-85/0124, prepared for Gas Research Institute and Department of Energy, June 30,
1985.
34. Spaite, Paul W., Dennis A. Dalrymple, and Gordon C Page, Radian Corporation, Characterization
and Disposal of Coal Gasification Waste Products. Phase II. Topical Report. GRI 81/0098, prepared
for Gas Research Institute, April 1987.
35. Faber, J.H., "Power Plant Ash Utilization and Energy Conservation Effects," Proceedings of the Sixth
Mineral Waste Utilization Symposium. Chicago, EL, May 2-3,1978, pp. 44-51.
36. Luecke, Richard H., Assessment of Solvent Extraction for Treatment of Coal-Gasifier Wastewater.
Final Report. DOE/EV/04034-T1, 1981.
37. Bombaugh, Karl J. and William J. Rhodes, "Discharges from Coal Gasification Plants," Environmental
Science and Technology. Vol. 22, No. 12, 1988, pp.1389-1396.
38. Bombaugh, Karl J., Milan Milosavljevic, and T. Kelly James, "Comparison of Leachable Trace
Element Levels in Coal Gasifier Ash with Levels in Power Plant Ash," Fuel. Vol. 63, April 1984, pp.
505-509.
39. Bern, Joseph, Ronald D. Neufeld, and Maurice A. Shapiro, University of Pittsburgh, Solid Waste
Management of Coal Conversion Residuals From a Commercial-Size Facility: Environmental
Engineering Aspects. DOE/ET/20023-5, prepared for U.S. Department of Energy: Pittsburgh Energy
Technology Center, November 30,1980.
40. Gold, Harris and David J. Goldstein, Water Purification Associates, Water-related Environmental
Effects in Fuel Conversion: Volume I. Summary. EPA-600/7-78-197a, Interagency
Energy/Environment R&D Program Report, prepared for Industrial Environmental Research
Laboratory, ORD, U.S. Environmental Protection Agency, October 1978.
41. "Texaco Coal Gasifier a Candidate for Waste Disposal With or Without Coal Firing," Clean-Coal
Svnfuels Letter. June 10,1988, p. 2.
42. Singh, S.P.N., J.F. Fisher, and G.R. Peterson, Evaluation of Eight Environmental Control Systems
for Low-BTU Coal Gasification Plants. ORNL-5481, Oak Ridge National Laboratory, U.S.
Department of Energy, March 1980.
43. Castaldi, F.J., W. Harrison, and D.L. Ford, Wastewater and Sludge Control - Technology Options for
Svnfuels Industries. Volume 1: Slagging. Fixed-Bed Lignite Gasification. ANL/ES-115, Vol. 1,
prepared for Argonne National Laboratory, U.S. Department of Energy, February 1981.
44. Cowan, Brent W., James A. Thompson, and Enos L. Stover, "Petroleum Processing and Synthetic
Fuels," Journal of the Water Pollution Control Federation. June 1987, pp. 461*464.
45. Cowan, Brent W. and Enos L. Stover, "Petroleum Processing and Synthetic Fuels," Journal of the
Water Pollution Control Federation. June 1986, pp. 571-574.
46. Cowan, Brent W, James A. Thompson, and Enos L. Stover, "Petroleum Processing and Synthetic
Fuels," Journal of the Water Pollution Control Federation. June 1988, pp. 890-893.
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B-5-4 Appendix B-5: List of Published Reports
47. Kostial, Krista, Ivan Rabar, Maja Blanusa, Dinko Kello, Tea Maljkovic, Marcia Landeka, Anka
Bunarevic, and Jerry F. Stara, "Chronic and Reproduction Studies in Rats Exposed to Gasifier . h
Leachates," The Science of the " tal Environment. 1982, pp. 133-147.
48. Rabar, I., T Maljkovic, M. Blanusa, K. Kostial, D. Kello, A. Bunarevic, and J.F. Stara, Tbxicologic
Studies of Emissions From a Coal Gasification Process - A Chronic Feeding Study," Arh. Hie. Rada
Tbksikol. Vol. 35, 1984, pp. 255-262.
49. Wiltsee, George A and \Vfcrrack G. Willson, Gasification of Low-Rank Coals: Technology Status
and Recent Research. DOE/FE/60181-165, prepared for Office of Fossil Energy, U.S. Department of
Energy, September 1985.
50. Eklund, A. Gwen, Radian Corp., Coal Gasification Environmental Data Summary: Solid Wastes and
Bv-Product Tars. EPA/600/7-86/015C, prepared for Air and Energy Engineering Research Laboratory,
ORD, U.S. Environmental Protection Agency, April 1986.
51. Boegly, WJ. Jr., H.W. Wilson, Jr., CW. Francis and EC Davis, Experimental Studies on the Land
Disposal of Coal Gasification Residues. Environmental Sciences Division, Oak Ridge National
Laboratory.
52. Gaines, L.L., W.H. Klausmeier, EP. Lynch, and A.D. Tevebaugh, Opportunities for By-product
Recovery in Svnfuel Plants. ANL/CNSV-48, Argonne National Laboratory, U.S. Department of
Energy, February 1984.
Copper
53. Wozniak, K., "Cutting Property Assessment of Copper Slag," Metal Finishing. November 1988, pp.
37-40.
54. Jordan, C.E, G.V. Sullivan, and ED. Scott, Recovery of Copper From Granulated Blast Furnace
Slag. RI 8279, Bureau of Mines, U.S. Dept of the Interior, FY 1977.
55. Robinson, K.E and H.M Eivemark, Floodplain Landfill with Mill Tkiiinos. OFR 200-83, Bureau of
Mines, U.S. Department of the Interior, July 1983.
56. Charlie, W.A, D.O. Doehring, D.S. Dumford, and J.P. Martin, "Dewatering Tailings Impoundments:
Interior Drains," Seventh Panamerican Conference, (no date), pp. 807-817.
57. Bair, Karen, "Asarco Reduces Costs at Two Copper Mines," American Metal Market. Vol. 95, April
24, 1987.
58. Bonn, Russel R. and Jeffrey D. Johnson, Environmental Services & Technology, Dust Control On
Active Tailings Ponds. OFR 112-83, Bureau of Mines, U.S. Dept. of the Interior, February 1983.
59. Nelson, J.D., S.R. Abt, R.L. Volpe, D. van Zyle, N.E Hinkle, and W.P. Staub, Colorado State
University and Oak Ridge National Laboratory, Methodologies for Evaluating Long-Term
Stabilization Designs of Uranium Mill Tailings Impoundments. NUREG/CR-4620, ORNL/TM-1006,
prepared for U.S. Nuclear Regualatory Commission, June 1986.
60. Lapakko, Kim A, James D. Strudell, and A Paul Eger, Minnesota Department of Natural Resources,
Low-Cost Removal of Trace Metals From Copper-Nickel Mine Stockpile Drainage. Volume II. Trace
Metal Sequestration By Peat. Other Organics. Tailings and Soils: A Literature Review. OFR 20B-87,
prepared for Bureau of Mines, U.S. Department of the Interior, August 1986.
61. Perry, Robert D. and Frank C. Kresse, Harding-Lawson Associates, Development of Methods for
Reclaiming Abandoned Tailings Ponds and Dams: ^jlume I. OFR 40(l)-82, prepared for Bureau
of Mines, U.S. Department of the Interior, June 1981.
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Appendix B-5: List of Published Reports B-5-5
62. Lapakko, Kim A,, A. Paul Eger, and James D. Strudell, Minnesota Department of Natural Resources,
Low-Cost Removal of Trace Metals From Copper-Nickel Mine Stockpile Drainage. Volume I.
Laboratory and Field Investigations. OFR 20A-87, prepared for Bureau of Mines, U.S. Department
of the Interior, August 1986.
63. White, Lane, "Copper Recovery from Flash Smelter Slags: Outokumpu Upgrades Sorting of Slags and
Flotation of Copper," Engineering and Mining Journal. January 1986, pp. 36-39.
64. Das, R.P., S. Anand, K. Sarveswara Rao, and P.K. Jena, "Leaching Behavior of Copper Converter Slag
Obtained Under Different Cooling Conditions," Trans. Institution of Mining and Metallurgy (Section
C: Mineral Process. Extr. Metallurgy"). Vol. 96, September 1987, pp. C156-C162.
65. Clarkson, J.F., R.H. Johnson, E. Siegal, and W.M. Vlasak, "Utilization of Smelter Slags at White Pine
Copper Division," Proceedings of the Sixth Mineral Waste Utilization Symposium. Chicago, IL, May
2-3, 1978, pp. 93-101.
66. Chung, C.H., T. Mizuno, and J.D. Mackenzie, "Iron Recovery and Glass Fiber Production From
Copper Slag," Proceedings of the Sixth Mineral Waste Utilisation Symposium. Chicago, DL, May 2-3,
1978, pp. 144-148.
67. Douglas, Esther and Paul R. Mainwaring, "Hydration and Pozzolanic Activity of Nonferrous Slags,"
American Ceramic Society Bulletin. Vol. 64, No. 5,1985, pp. 700-706.
68. McKern, Robert B., The Industrial Economics of Copper Processing," Natural Resources Forum.
Vol. 5, 1981, pp. 227-248.
69. Meyers, R.A., J.W. Hamersma, and M.L. Kraft, "Sulfur Dioxide Pressure Leaching: New Pollution-
Free Method to Process Copper Ore," Environmental Science & Technology. Vol. 9, No. 1, January
1975, pp. 70-71.
70. Jacobi, J.S., "Recent Developments in the Recovery of Copper and Associated Metals from Secondary
Sources," Journal of Metals. February 1980, pp. 10-14.
71. Lockhart, N.C, "Electroosmotic Dewatering of Clays. I. Influence of Voltage," Colloids and Surfaces.
Vol. 6, 1983, pp. 229-238.
72. Lockhart, N.C, 'Electroosmotic Dewatering of days. II. Influence of Salt, Acid, and Flocculants,"
Colloids and Surfaces. VoL 6,1983, pp. 239-251.
73. Day, A.D. and K.L. Ludeke, "Stabilization of Copper Mine Wastes in a Semi-Arid Environment With
Perennial Grasses," Journal of Arid Environments. VoL 5,1982, pp. 285-290.
74. Ritcey, G.M., "Some Economic Considerations in the Recovery of Metals By Solvent Extraction
Processing," CIM Bulletin. June 1975, pp. 85-94.
75. Rampacek, Carl and James T Dunham, "Copper Ore Processing - U.S. Practices and Trends," Mining
Congress Journal. February 1976, pp. 43-50.
76. Bingham, Edward R., "Waste Utilization in the Copper Industry," Proceedings of the First Mineral
Waste Utilization Symposium. Chicago, IL, March 27-28,1968, pp. 73-77.
77. Chafet, A., Guidelines for the Design. Construction, and Operation of Tailings Ponds and Dams.
NITS PB-256 489, Arthur B. Chafet & Associates, January 1974.
78. Grotowski, A.T. and KJ. Zmudzinski, "Treatment of Sulphide-Oxide Copper Ore by Segregation,"
International Journal of Mineral Processing. VoL 21, March 25,1987, pp. 293-305.
79. "Smelter Waste Builds Highway Embankments,11 Roads & Streets. Jury 1975, pp. 50-51.
80. Narain, Kartik A., "Recovery of Elemental Sulfur and Metal Values from Tailings from Copper
Recovery Processes," U.S. Patent No. 4,236,918, December 2,1980.
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B-5-6 Appendix B-5: List of Published Reports
81. Narain, Kartik A., "Recovery of Elemental Sulfur and Metal Values from Tailings from Copper
Recovery Processes," U.S. Patent No. 4,138,248, February 6, 1979.
82. Floyd, J.M. and PJ. Mackey, "Developments in the Pyrometallurgical Treatment of Slag: A Review
of Current Technology and Physical Chemistry," Extraction Metallurgy '81 - Papers Presented at the
Symposium. London, September 21-23, 1981.
83. PEDCo Environmental, Inc., Industrial Process Profiles for Environmental Use. Chapter 29: Primary
Copper Industry. EPA-600/2-80-170, Environmental Protection Technology Series, Industrial
Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency, July 1980.
Elemental Phosphorus
84. "OxyChem Process Hikes Phosphorus Production,* The Journal of Commerce. June 2, 1988.
85. Stula, R.T., R.E. Belanger, C.L. Clary, R.E May, M.E Spaeth, and J.B. Swenson, Airborne Emission
Control Technology for the Elemental Phosphorus Industry - Final Report to the Environmental
Protection Agency. Prepared for ORP, U.S. Environmental Protection Agency, January 26, 1984.
86. Andrews, Vernon E. and Tom Bibb, Emissions of Naturally Occurring Radioactivity: Stauffer
Elemental Phosphorus Plant. EPA-520/6-82-019, ORP, U.S. Environmental Protection Agency,
November 1982.
87. Andrews, Vernon E. and Tom Bibb, Emissions of Naturally Occurring Radioactivity. Monsanto
Elemental Phosphorus Plant. EPA-520/6-82-021, ORP, U.S. Environmental Protection Agency,
November 1982.
88. Radian Corporation, Emission Testing of Calciner Off-Gases at Stauffer Chemical Elemental
Phosphorus Plant. Silver Bow. Montana - Emission Test Final Report. Volume I, DCN #84-231-060-
57-04, Prepared for ORP, U.S. Environmental Protection Agency, August 1984.
89. Radian Corporation, Emission Testing of Calciner Off-Gases at Monsanto Elemental Phosphorus
Plant. Soda Springs. Idaho - Emission Test Final Report Volume I, DCN #84-231-060-58-07,
Prepared for ORP, U.S. Environmental Protection Agency, August 1984.
90. Science Applications, Inc., Task 1 - Status of Compliance. Technical Support: Control Technology
Alternatives and Costs for Compliance - Elemental Phosphorus Plants. Prepared for ORP, U.S.
Environmental Protection Agency, August 19,1983.
91. U.S. Environmental Protection Agency, ORP, Radiological Surveys of Idaho Phosphate Ore
Processing - The Thermal Process Plant. Technical Note: ORP/LV-77-3, November 1977.
Ferrous Metals
92. Mathias, William M. and Adnan Goksel, "Reuse of Steel Mill Solid Wastes," Iron and Steel Engineer.
December 1975, pp. 49-51.
93. Gnaedinger, John P, "Open Hearth Slag - A Problem Waiting to Happen," Journal of Performance
of Constructed Facilities. ASCE, VoL 1, No. 2, May 1987, pp. 78-83.
94. Chementator, "Graphite Flake Could Be Produced at a Fraction of the Current Cost," Chemical
Engineering. June 1989, pp. 17-19.
95. Chementator, "A Collective Method Cleans Up Steelmaking Slurries," Chemical Engineering.
September 1989, pp. 17-19.
96. Meermans, Marcia J., "The Cost of dean Air & Waiter in the Metals and Plastics Industries," Metals
Engineer. July 1982, pp. 36-41.
97. "EAF-Based Company Becomes Sixth Largest Steel Producer," I & SM. January 1989, p. 6.
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Appendix B-5: Ust of Published Reports B-5-7
98. "Sludge Conversion Process Helps USS Cut Coke Plant >taste," Iron Age. August 1989, p. 15.
99. Ostroff, Jim, "Will EPA's Dust Rules Choke Steel?" Iron Age. June 1988, pp. 21-27.
100. Lu, W-K, "Recycling Steel Plants and New Process Development," Recycling in the Steel Industry.
Proceedings of the First Process Technology Conference. Washington, D.C., Vol. 1, March 25-26,
1980, pp. 23-31.
101. Shinoda, Sakuei, Akira Ohta, and Jun Okamoto, "Total Raw Materials and Energy Recycling System
of Newly Built Keihin Works," Recycling in the Steel Industry. Proceedings of the First Process
Technology Conference. Washington, D.C., Vol. 1, March 25-26, 1980, pp. 32-47.
102. Pasztor, Laszlo, "Generation and Recycling of Pollution Control Residues in the Steel Industry,"
Recycling in the Steel Industry. Proceedings of the First Process Technology Conference. Washington,
D.C., Vol. 1, March 25-26, 1980, pp. 48-54.
103. Harris, Morley M., "The Use of Steel-Mill Waste Solids in Iron and Steelmaking," Recycling in the
Steel Industry. Proceedings of the First Process Technology Conference. Washington, D.C, Vol. 1,
March 25-26, 1980, pp. 62-71.
104. Jones, D.E. and SJ. Murrie, "Utilization of Steelplant Slag Products in Australia," Recycling in the
Steel Industry. Proceedings of the First Process Technology Conference. Washington, D.C, Vol. 1,
March 25-26, 1980, pp. 146-157.
105. Piret, Jaques J., Andre P. Lesgardeur, and Andre M. Delmarcelle, "Experimental Road Built with
BOF Slag at Cockerill-Seraing," Recycling in the Steel Industry. Proceedings of the First Process
Technology Conference. Washington, D.C, Vol. 1, March 25-26,1980, pp. 158-166.
106. Salgusa, Makoto, Sumio Yamada, and Kiyotosh Oda, "Recycling of Converter Slag in Ohiba Works,"
Recycling in the Steel Industry. Proceedings of the First Process Technology Conference. Washington,
D.C, Vol. 1, March 25-26, 1980, pp. 168-171.
107. Pargeter, John K. and Harry Joseph Weil, "The INMETCO Process for Recovery of Metals from
Steelmaking Wastes," Recycling in the Steel Industry. Proceedings of the First Process Technology
Conference. Washington, D.C, Vol. 1, March 25-26,1980, pp. 172-177.
108. Hissel, J., J. Frenay and J. Herman, "Pilot Study of a Caustic Soda Treatment Process for Reducing
the Zinc and Lead Content of Waste Products from Iron- and Steel-Making Processes," Recycling in
the Steel Industry. Proceedings of the First Process Technology Conference. Washington, D.C, Vol. 1,
March 25-26, 1980, pp. 178-183.
109. Rausch, H. and H. Serbent, "Beneficiation of Steel Plant Waste Oxides By Rotary Kiln Processes,"
Proceedings of the Sixth Mineral Waste Utilization Symposium. Chicago, IL, May 2-3,1978, pp. 345-
351.
110. Mueller B. and G. von Struve, "Design of Pelletizing Plants for Blast Furnaces and Direct Reduction
Processes Incorporating In-plant Fines," Agglomeration 77: Proceedings of the 2nd International
Symposium on Agglomeration. Volume 1. Atlanta, GA, March 6-10,1977, pp. 25-45.
111. Lofgren, Olof, Claes-Goran Nilsson, and Rolf Odman, "Operational Experiences on Balling Circuits
With Drums, Discs and Roller Seed Screens." Agglomeration 77: Proceedings of the 2nd International
Symposium on Agglomeration. Volume 1. Atlanta, GA, March 6-10,1977, pp. 425-435.
112. Greenwalt, Richard B. and James G. Stephenson, The Role of Agglomeration in Direct Reduction
Processes," Agglomeration 77: Proceedings of the 2nd International Symposium on Agglomeration.
Volume 2. Atlanta, GA, March 6-10,1977, pp. 765-783.
113. Goksel, M. Adnan, "Fundamentals of Cold Bond Agglomeration Processes,* Agglomeration 77:
Proceedings of the 2nd International Symposium on Agglomeration. Volume 2. Atlanta, GA, March
6-10, 1977, pp. 877-900.
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B-5-8 Appendix B-5: List of Published Reports
114. Imperato, L. George, "Production and Performance of Carbonate-Bonded Pellets," 27th Ironmaking
Conference Proceedings. (AIME), Vol. 27, 1968, pp. 41-45.
115. Kanda, Yoshio, Hiroki Tbyozawa, Yasuteru Yamada, and Masaru Nakamura, "Direct Reduction
Process for Iron Industries Waste Fines," 36th Ironmaking Conference Proceedings. (AIME), Vol. 36,
1977, pp. 398-410.
116. Moore, John J., "Recent Developments in Ferrous Production Metallurgy," Journal of Metals. April
1983, pp. 53-62.
117. ACI Committee 226, "Ground Granulated Blast-Furnace Slag as a Cementitio'is Constituent in
Concrete," American Concrete Institute Material Journal. July-August 1987, pp. 327-342.
118. Emery, J.J., CS. Kim, and R.P. Cotsworth, "Base Stabilization Using Palletized Blast Furnace Slag,"
Journal of Testing and Evaluation. January 1976, pp. 94-100.
119. Emery, John J., "New Uses of Mettalurgical Slags," CIM Bulletin. December 1975, pp. 60-68.
120. Smith, D.W., "Steel Industry Wastes," Journal of Water Pollution Control Federation. June 1976, pp.
1287-1293.
121. Cotsworth, R.P., "Use of Pelletized Slag in Concrete Masonry Units," Journal of Testing and
Evaluation. March 1978, pp. 148-152.
122. Wachsmuth, Frank, Jurgen Geiseler, Wolfdietrich Fix, Klaus Koch, Klaus Schwerdtfeger,
•Contribution to the Structure of BOR-Slags and Its Influence on Their Volume Stability," Canadian
Metallurgical Quarterly, pp. 279-284.
123. Scott, P.W., S.R. Critchley, F.C.F. Wilkinson, "The Chemistry and Mineralogy of Some Granulated
and Pelletized Blast Furnace Slags," Mineraloeical Magazine. March 1986, pp. 141-147.
124. Lindberg, Nils G. and Thomas S. Falk, The COBO Process Applied to Chromite Agglomeration,"
CIM Bulletin. September 1976, pp. 117-126.
125. Eacott, J.G., McRobinson, E. Busse, J.E. Burgener, and RE. Burgener, Techno-Economic Feasibility
of Zinc and Lead Recovery from Electric Arc Furnace Baghouse Dust," CIM Bulletin. September
1984, pp. 75-81.
126. Fine, M.M. and L.F. Heising, "Iron Ore Waste - Occurrence, Beneficiation and Utilization,"
Proceedings of the First Mineral Waste Utilization Symposium. Chicago, IL, March 27-28,1968, pp.
67-72.
127. George, Harry D., The Handling, Processing and Marketing of Steel-Making Slag," Proceedings of
the First Mineral Waste Utilization Symposium. Chicago, EL, March 27-28,1968, pp. 80-83.
128. Gouvens, Paul R., "Utilization of Foundry Waste By-Products," Proceedings of the First Mineral
Wfrste Utilisation Symposium. Chicago, IL, March 27-28,1968, pp. 84-98.
129. Weidner, Thomas H. and John W. Kreiger, "Development and Application of the Green Pelletizing
Process to Produce Agglomerates for BOF and Open Hearth Use," Recycling in the Steel Industry.
Proceedings of the First Process Technology Conference. Washington, D.C, March 25-26,1980, pp.
72-76.
130. Kaiser, F.T and L.L. French, "Supplementary Hot Metal From Waste Oxides," Recycling in the Steel
Industry. Proceedings of the First Process Technology Conference. Washington, D.C., March 25-26,
1980, pp. 77-84.
131. Pazdej, R. and J.M. Steiler, "New Treatment Possibilities of BF/BOF Zinc (and Lead) Bearing Dusts,"
Recycling in the Steel Industry. Proceedings of the First Process Technology Conference. Washington,
D.C, March 25-26, 1980, pp. 85-103.
-------
Appendix B-5: List of Published Reports B-5-9
132. Watson, J. and Y. Wang, "Multi-stage, Multi-force Dewatering of Steelmaking Sludges," Powder
Technology. 1989, pp. 49-53.
133. Watson, J. and B. Gantam, "Synergistic Dewatering Process for Mineral Slurries," University of
Missouri-Rolla.
134. Furukawa, Tsukasa, "Steel Firms Eye Dust-to-Pellet System," Energy User News. August 8, 1977, p.
10.
135. Volin, M.E., et al, "Agglomerated Mineral Products and Method of Making Same," U.S. Patent No.
3,235,371, February 15, 1968.
136. Berry, William A., "Cementitious Binder for Consolidated Fill," U.S. Patent No. 4,715,896, December
29, 1987.
137. Larpondeur, Bernard J. and Joseph W. Pasquali, "Method of Recovering Iron Oxide From Fume
Containing Zinc and/or Lead and Sulfur and Iron Oxide Panicles," U.S. Patent No. 3,547,623,
December 15, 1970.
138. Gocksel, Mehmet A., "Method for Agglomerating Steel Plant Waste Dusts," U.S. Patent No.
3,895,088, July 15, 1975.
139. Kreiger, John W. and Charles E. Jablonski, "Method for Preparing Dry-Collected Fume for Use in
Metallurgical Furnaces," U.S. Patent No. 4,003,736, January 18, 1977.
140. Miyoshi, H., et al., "Process for Strengthening Soft Soil," U.S. Patent No. 4,465,518, August 14,1984.
141. Emery, John J., "New Uses of Metallurgical Slags," CIM Bulletin. December 1975, pp. 60-68.
142. George, Harry D. and Elliot B. Boardman, "IMS-Grangcold Pelletizing System for Steel Mill Waste
Material," Iron and Steel Engineer. November 1973, pp. 60-64.
143. Goksel, Mehmet Adnan, "Treatment of Zinc Rich Steel Mill Dusts for Reuse in Steel Making
Processes," U.S. Patent No. 3,770,416, November 6,1973.
144. Kreiger, John W, "Method for Agglomerating Wet-Collected Fume for Use in Metallurgical Furnaces
and Agglomerates Produced Thereby," U.S. Patent No. 4,004,916, January 25,1977.
145. Goskel, M.A. and W.M. Mathias, "Recycling Steel Plant Fine Materials By Using the MTU Cold
Bond Process," Proceedings. Institute for Briquetting and Agglomeration. Volume 14.1975, pp. 105-
118.
146. Adams, CJ., Recycling of Steel Plant Waste Oxides - A Review. CANMET Report 79-34, March
1979.
147. Kenahan, C.B., R.S. Kaplan, J.T. Dunham, and D.G. Linnehan, Bureau of Mines Research Programs
on Recycling and Disposal of Mineral-. Metal-, and Energy-Based Wastes. Information Circular 8595,
Bureau of Mines, U.S. Department of Interior, 1973.
148. Katari, VS., R.W. Gerstle, and Terry Parsons, Industrial Process Profiles for Environmental Use.
Chapter 24: The Iron and Steel Industry. EPA-600/2-77-023x, Environmental Protection Technology
Series, Industrial Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency,
February 1977.
-------
B-5-10 Appendix B-5: List of Published Reports
Hydrofluoric Acid
149. Tfewari, R.P. and P.K. Mehta, "Fluorogypsum as a Mineralizer in Portland Cement Clinker
Manufacture, American Ceramic Society Bulletin. 1972. op. 461-463.
150. Dow Chemical U.S.A., Industrial Process Profiles fc Environmental Use. Chapter 16: "he
Fluorocarbon-Hvdroeen Fluoride Industry. EPA-600/2-77-023p. Environmental Protection Tfechn ; gy
Series, Industrial Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency,
February 1977.
Primary Lead
151. Kumar, Rakesh and A.K. Biswas, "Zinc Recovery from Zawar Ancient Siliceous Slag,"
Hvdrometallurgy. 1986, pp. 267-280.
152. PEDCo Environmental, Inc., Industrial Process Profiles for Environmental Use. Chapter 27: Primary
Lead Industry. EPA-600/2-80-168, Environmental Protection Technology Series, Industrial
Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency, July 1980.
Phosphoric Acid
153. Saylak, D., A.M. Gadalla, and C.C. Yung, "Strength Development in Waste Industrial Gypsum from
the Dihydrate Wet Process," Industrial &. Engineering Oiemistrv Research. VoL 27, No. 4, April 1988,
pp. 707-712.
154. Smith, Adrian, "Disposal of Acid-bearing and Acid-generating Sludges in the Fertilizer Manufacturing
Industry," Canadian Journal of Civil Engineering. VoL 14, No. 1, February 1987, pp. 1-6.
155. "Phosphogypsum Wastes Take to the Road," Chemical Week. April 25,1984, pp. 52-54.
156. McGinty, Robert and Joseph F. Dunphy, "A New Process for Phosphogypsum," Chemical Week.
October 9, 1985, p. 32.
157. "Well Field is Radioactive," Engineering News - Record. VoL 219, No. 3, July 16,1987, pp. 23-24.
158. "Road Mix Has Mixed Reviews," Engineering News • Record. VoL 218, No. 25, June 18,1987, pp. 33-
34.
159. Short, Herb, "Future Fertilizer Plants: What Will They be Like?" Chemical Engineering. April 1,
1985, pp. 21-25.
160. Chementator, "A Way to Make Phosphoric Acid by a New Dihydrate Route," Chemical Engineering.
April 28, 1986, p. 9.
161. Ho, Robert K.H., and W.H. Zimpfer, Comments on the Investigation of Phosphogypsum for
Embankment Construction. FL/DOT/BMR-84-276, State of Honda Dept of Transportation, Bureau
of Materials and Research, June 1985.
162. May, Alexander and John W. Sweeney, Evaluation of Radium and Toxic Element Leaching
Characteristics of Florida Phosphogvpsum Stockpiles. RI 8776, Bureau of Mines, U.S. Department
of the Interior, June 1983.
163. Pena, N., Utilization of the Phosphogvpsum Produced in the Fertilizer Industry. UNIDO/IS.533,
United Nations Industrial Development Organization (UNIDO), May 1985.
164. Hartley, J.N. and H.D. Freeman, Radon Flux Measurements on Gardinier and Rovster
Phosphogvpsum Piles Near Tamoa and Mulberry. Florida. EPA 520/5-85-029, prepared for U.S.
Environmental Protection Agency, Eastern Environmental Radiation Facility, January 1986.
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Appendix B-5: List of Published Reports B-5-11
165. Horton, T.R., R.L. Blanchard, and S.T. Windham, A Study of Radon and Airborne Paniculates at
Phosphogypsum Stacks in Central Florida. EPA 520/5-88-021, prepared for U.S. Environmental
Protection Agency, Eastern Environmental Radiation Facility, October 1988.
166. "Officials Talk of Closing Gardinier After 40,000 Gallon Phosphoric Acid Spill," Green Markets. Vol.
12, No. 19, May 16, 1988.
167. Moussa, D., J.J. Crispel, CL. Legrand and B. Thenoz, "Laboratory Study of the Structure and
Compactibility of Tunisian Phosphogypsum (SFAX) for Use in Embankment Construction,"
Resources and Conservation. Vol. 11, 1984, pp. 95-116.
168. Muthukumar, G. and P.V.R. Subrahmanyam, "Phosphatic Fertilizer Waste Water Treatment
Employing Lime and Byproduct Phosphogypsum," Indian Journal of Environmental Health. Vol. 29,
1987, pp. 117-127.
169. Aleshin, Eugene, "Comments on Utilization of Mining and Mineral Wastes," Proceedings of the Sixth
Mineral Waste Utilization Symposium. Chicago, EL, May 2-3, 1978, pp. 77-78.
170. "Gypsum Substitute Could Ease U.S. Supply Situation," American Paint & Coatings Journal. May 19,
1986, p. 18.
171. Kouloheris, A.P., Zellars-Williams, Inc., Evaluation of Potential Commercial Processes for the
Production of Sulfuric Acid from Phosphogypsum. 01-002-001, Florida Institute of Phosphate
Research, October 1981.
172. Chang, Wen F., David A. Chin, and Robert Ho, Phosphogvpsum for Secondary Road Construction.
Prepared for Florida Institute of Phosphate Research, 1989.
173. "IMC Fertilizer Plans New Gypsum Stack, Will Install Plastic Liner to Protect Ground," Green
Markets. Vol. 13, No. 34, August 29,1989, p. 9.
174. "Freeport Funds Gypsum Recycling Research," Green Markets, Vol. 13, No. 10, March 13,1989, p.
8.
175. "Agrico," Green Markets. Vol. 13, No. 3, January 23, 1989, p. 4.
176. "Gardinier Building New Gypsum Stack But Environmentalists Still Complain," Green Markets. Vol.
12, No. 14, April 11, 1988, p. 8.
177. Cox, James L., "Phosphate Wastes," Proceedings of the First Mineral Waste Utilization Symposium.
Chicago, EL, March 27-28, 1968, pp. 50-61.
178. "Soviet Union Plans Major Fertilizer Capacity Expansion," European Chemical News. February 7,
1983, p. 26.
179. Nyers, J.M., G.D. Rawlings, E~A Mullen, CM. Moscowitz, and R.B. Reznik, Monsanto Research
Corp., Source Assessment: Phosphate Fertilizer Industry. EPA-600/2-79-019C, Environmental
Protection Technology Series, prepared for Industrial Environmental Research Laboratory, ORD,
U.S. Environmental Protection Agency, May 1979.
180. Lloyd, G. Michael, Jr., Phosphogvpsum: A Review of the Florida Institute of Phosphate Research
Programs to Develop Uses for Phosphogvpsum. Publication No. 01-000-035, Florida Institute of
Phosphate Research, December 1985.
181. Rice, David A., Olice C Carter, Jr., Alexander May, Margaret M. Ragin, and Robert G. Swanton,
Recovery of Sulfur From Phosphogvpsum: Conversion of Calcium Sulfide to Sulfur. Report of
Investigations 9297, Bureau of Mines, U.S. Department of the Interior, 1990.
182. May, Alexander and John W. Sweeney, Assessment of Environmental Impacts Associated With
Phosphogvpsum in Florida. Report of Investigations 8639, Bureau of Mines, U.S. Department of the
Interior, 1982.
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B-5-12 Appendix B-5: List of Published Reports
183. Zellars-Williams Company, Jim G. Tavrides, Assessment of Present Phosphate Mining and
Beneficiation Practice and the Evaluation of Alternative Technology. Publication No. 04-031-068,
Florida Institute of Phosphate Research, October 1988.
184. Bureau of Mines, U.S. Department of the Interior, Use of Florida Phosphogypsum in Synthetic
Construction Aggregate. Publication No. 01-008-026, Honda Institute of Phosphate Research,
September 1983.
185. Zellars-Williams, Inc., A.P. Kouloheris, Evaluation of Potential Commercial Processes for the
Production of Sulfuric Acid From Phosphogypsum. Publication No. 01-002-001, Florida Institute of
Phosphate Research, October 1981.
186. Lundgren, Dale A. and Cumbum N. Rangaraj, Fugitive Dust Control for Phosphate Fertilizer.
Publication No. 01-015-069, Florida Institute of Phosphate Research, December 1988.
187. Post, Buckley, Schuh & Jernigan, Inc., Radioactivity in Foods Grown on Florida Phosphate Lands.
Publication No. 05-015-038, Florida Institute of Phosphate Research, March 1986.
188. Osmond, J.K., J.B. Cowan, GL. Humphreys, and B.E Wagner, Radioelement Migration in Natural
and Mined Phosphate Terrains. Publication No. 05-002-027, Florida Institute of Phosphate Research,
February 1985.
189. Chang, Wen F. and Murray I. Mantell, Engineering Properties and Construction Applications of
Phosphogypsum. Phosphate Research Institute, University of Miami, University of Miami Press, 1990.
190. Palmer, Jay W. and A.P. Kouloheris, Slimes Waste Solidification with Hvdratable Calcium Sulfate.
paper to be presented at the University of Miami Civil Engineering Department Seminar on
Phosphogypsum on April 25-27,1984.
191. Chang, Wen E, A Demonstration Project: Roller Compacted Concrete Utilizing Phosphogypsum.
Publication No. 01-068-072, Florida Institute of Phosphate Research, December 1988.
192. Florida Institute of Phosphate Research (sponsor), Proceedings of the Second International
Symposium on Phosphogypsum. Volume I. Publication No. 01-037-055, Organized by the University
of Miami, January 1988.
193. Florida Institute of Phosphate Research (sponsor), Proceedings of the Second International
Symposium on Phosphogypsum. Volume II. Publication No. 01-037-055, Organized by the University
of Miami, January 1988.
194. University of Miami and Florida Institute of Phosphate Research (sponsors), Proceedings of the
Second Workshop on By-Products of Phosphate Industries. Publication No. 01-028-028, Honda
Institute of Phosphate Research, May 1985.
195. Florida Institute of Phosphate Research (sponsor), Proceedings of the Third Workshop on Bv-
Products of Phosphate Industries. Publication No. 01-031-046, Organized by the University of Miami,
November 1986.
196. Muehlberg, P.E, B.P. Shepherd, and Terry Parsons, Industrial Process Profiles for Environmental
Use. Chapter 17: The Gypsum and Wallboard Industry. EPA-600/2-77-023q, Environmental
Protection Technology Series, Industrial Environmental Research Laboratory, ORD, U.S.
Environmental Protection Agency, February 1977.
197. Parikh, S.B., M.H. Mehta, and VA. Sanghani, "R & D, Manufacturing and Application Aspects of
Phosphogypsum,1' Presented at the Second International Symposium on Phospho-gypsum, sponsored
by the Florida Institute of Phosphate Research, December 10-12,1986.
198. Shainberg, I., M.E Sumner, W.P. Miller, M.P.W. Rrina, M-A. Pavan, and M.V Fey, "Use of Gypsum
on Soils: A Review," in B.A. Stewart, (ed.), Advances in Soil Science, \folume 9. New York:
Springer-Verlag New York Inc., 1989, pp. 1-111.
-------
Appendix B-5: List of Published Reports B-5-13
199. Baird, J.V and E.J. Kamprath, "Agricultural Use of Phosphogypsum on North Carolina Crops,"
Proceedings of The International Symposium on Phosphogypsum. sponsored by the Florida Institute
of Phosphate Research, November 5-7, 1980, pp. 157-169.
200. Lindeken, C.L., "Radiological Considerations of Phosphogypsum Utilization in Agriculture,"
Proceedings of The International Symposium on Phosphogypsum. sponsored by the Florida Institute
of Phosphate Research, November 5-7, 1980, pp. 459-472.
201. Guimond, Richard J. and James M. Hardin, "Radioactivity Released from Phosphate-Containing
Fertilizers and from Gypsum," Radiation Physical Chemistry. Vol. 34, No. 2, pp. 309-315, 1989.
202. Burau, R.G., Agricultural Impact of 226RA in Gypsum Derived from Phosphate Fertilizer
Manufacture, (draft), October 8, 1976.
203. Smith, Adrian and Brian Wrench, "Aspects of Environmental Control of Phosphogypsum Waste
Disposal," Proceedings of the Eighth Regional Conference for Africa on Soil Mechanics and
Foundation Engineering. Harare, 1984, pp. 487-490.
204. Fitzgerald, Joseph E. and Edward L. Sensintaffar, "Radiation Exposure From Construction Materials
Utilizing Byproduct Gypsum From Phosphate Mining," (source unknown), pp. 351-367.
205. Lindeken, C.L. and D.G. Coles, "The Radium-226 Content of Agricultural Gypsums," (source
unknown), pp. 369-375.
206. Consolidated Minerals, Inc., Petition for Reconsideration and Request for Stay -- National Emission
Standard for Hazardous Air Pollutants: Radionuclides - Phosphogypsum Stacks: Docket No. A-79-11.
December 21, 1989.
207. United States Gypsum Company, Petition for Partial Reconsideration and Clarification, and Its
Opposition to The Fertilizer Institute's Petition for Partial Reconsideration and Request for a Stay -
- National Emission Standard for Hazardous Air Pollutants: Radionuclides -- Phosphogvpsum Stacks:
Docket No. A-79-11. February 9, 1990.
208. Palmer et al., "Process for Reducing Radioactive Contamination in Phosphogypsum," U.S. Patent No.
4,388,292, June 14, 1983.
209. Palmer et al., "Phosphohemihydrate Process for Purification of Gypsum," U.S. Patent No. 4,424,1%,
January 3,1984.
210. Palmer et al., "Phosphoanhydrite Process," U.S. Patent No. 4,452,770, June 5,1984.
211. Palmer, J.W. and J.C. Gaynor, "Phosphogvpsum Purification," Presented at the Clearwater, Florida
joint meeting of the Central Florida and Peninsular Florida sections of the American Institute of
Chemical Engineers, May 25, 1985.
212. Humphreys, Cynthia L., "Factors Controlling Uranium and Radium Isotopic Distributions in
Groundwaters of the West-Central Florida Phosphate District," Radon in Ground Water. NWWA,
pp. 171-189.
213. Block, Gladys, Genevieve M. Matanoski, Raymond Seltser, and Thomas Mitchell, "Cancer Morbidity
and Mortality in Phosphate Workers," Cancer Research. December 15,1988, pp. 7298-7303.
214. United States Gypsum Company, The High Purity. Readily Available Source of Calcium and Sulfur
for Peanuts. Source of Calcium and Sulfur for Cranberries.
215. Witkamp, GJ. and G.M. van Rosmalen, "Recrystallization of Calcium Sulfate Modifications in
Phosphoric Acid," pp. 377-405 (no date or title of publication).
216. van der Sluis, S., J.M.P. Omens, Y. Meszaros, J.A Wesselingh, and G.M. van Rosmalen, "Mass and
Heat Balances of a Clean Technology Phosphoric Acid Process," pp. 319-357 (no date or title of
publication).
-------
B-5-14 Appendix B-5: List of Published Reports
217. Moisset, J., "Location of Radium in Phosphogypsum and Improved Process for Removal of Radium
form Phosphogypsum," pp. 303-317 (no date or title of publication).
218. Roessler, C.E., "Radiological Assessment of the Application of Phosphogypsum to Agricultural Land,"
pp. 5-23 (no date or title of publication).
219. Malan, J.J., "Utilization of Phosphogypsum: Structure and Achievements of a Cooperative Research
Programme," pp. 131-139 (no date or title of publication).
220. Miller, W.P., D.E. Radcliffe, and M.E. Sumner, "The Effect of Soil Amendment with Phosphogypsum
on Clay Dispersion, Soil Conservation, and Environmental Quality," pp. 231-256 (no date or
publication).
221. U.S. Environmental Protection Agency, ORP, Radiological Surveys of Idaho Phosphate Ore
Processing - The Wet Process Plant. Technical Note: ORP/LV-78-1, April 1978.
222. EG&G Idaho, Inc., Evaluation of Relative Hazards of Phosphate and Wastes. DOE/LLW-24T,
Prepared for U.S. Department of Energy, March 1984.
Titanium Tetrachloride
223. Johnson, Eric, "Booming West German CPI Cope With Environmental Issues," Chemical Engineering.
October 24, 1988, pp. 35-41.
224. Lazorko, Lisa, Herbert Short, and Eric Johnson, TiO2's Future is Keyed to New Technologies,"
Chemical Engineering. January 1989, p. 37, 39, 41. (includes Editor's Page, "A Good Credo to Live
By," p. 5.)
225. Smith, Iain, Gordon M. Cameron, and Howard C Peterson, "Acid Recovery Cuts Waste Output,"
Chemical Engineering. February 3,1986, pp. 44-45.
226. Ryser, Jeffrey, Richard J. Zanetti, Herb Short, and Tuevo Tikkanen, "New Feed, New Technique
Enliven the T1O2 Scenario," Chemical Engineering. November 25,1985, pp. 18-20.
227. Ishizuka, Hiroshi, "Method and an Apparatus for Producing Titanium Metal from Titanium
Tetrachloride," U.S. Patent No. 4,441,925, April 10,1984.
228. Merrill, C.C, M.M. Wong, and D.D. Blue, Beneficiation of Titanium Chlorination Residues:
Preliminary Study. Report of Investigations 7221, Bureau of Mines, U.S. Department of Interior, 1969.
229. Merrill, C.C. and D.E. Couch, Separation of Columbium. Tantalum. Titanium, and Zirconium from
Titanium Chlorination Residues. Report of Investigations 7671, Bureau of Mines, U.S. Department
of Interior, (no date).
230. Heikel, Henrik R., "Process for Preparing a Pigmentary Titanium Dioxide," U.S. Patent No. 4,759,916,
July 26,1988.
231. Bunch, J.W., "Hydrochloric Acid From Industrial Waste Streams - The PORI Process," CIM Bulletin.
January 1975, pp. 96-100.
232. "Waste Acid Recovery Ends Industrial Emissions," Process Industries Canada. September 1987, pp.
5,9.
233. Tioxide's Ten-year Environmental Programme," Industrial Minerals. August 1988, p. 3.
234. Krispar Technologies, Inc., Study on Titanium Chlorination Solid Wastes. Minerals & Materials
Research Division, Bureau of Mines, U.S. Department of Interior, October 30,1987.
235. Katari, Vishnu S., and Timothy W. Devitt, Industrial Process Profiles for Environmental Use. Chapter
26: Titanium Industry. EPA-600/2-77-023Z, Environmental Protection Technology Series, Industrial
Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency, February 1977.
236. "Treating Wastes from Titanium Dioxide Plants," Sulphur 194. January-February 1988, pp. 24-31.
-------
Appendix B-5: List of Published Reports B-5-15
237. Titanium Dioxide in West Europe," Sulphur 144. September/October 1979, pp. 21-28.
238. Titova, L.V., N.V Gul'ko, I.P. Lyubliner, and I.N. Ermolenko, "Influence of the Components of
Chloride Wastes from TiCl4 Production on Formation of the Porous Structure of Fibrous Carbon
Adsorbents and of Ion-Exchangers Based on Them," Zhurnal Prikladnoi Khimii. Vol. 60, No. 7, July
1987, pp. 1495-1500.
239. Sinha, Hari N., "Effects of Oxidation and Reduction Temperatures, and the Addition of Ferrous
Chloride to Hydrochloric Acid, on the Leaching of Ilmenite," Titanium '80 Science and Technology:
Proceedings of the Fourth International Conference on Titanium, ed. H. Kimura and O. Izumi, Kyoto,
Japan, May 19-22, 1980, pp. 1919-1926.
240. Kulkarni, A.P., H.S. Ahluwalia, R.B. Subramanyam, N.K. Rao, TK. Mukherjee, R.S. Babu, and C.
Sridhar Rao, "Studies on Titanium Metal Extraction in India," Titanium '80 Science and Technology:
Proceedings of the Fourth International Conference on Titanium, ed. H. Kimura and O. Izumi, Kyoto,
Japan, May 19-22, 1980, pp. 1927-1936.
241. Ogawa, Minoru, Masato Aso, Hiroshi Matsunami, Shigenori Okudaira, Michiaki Iwagami, Takefumi
Irie, and Keizo Goda, "A Study of Titanium Resources and its Chlorination Process," Titanium '80
Science and Technology: Proceedings of the Fourth International Conference on Titanium, ed. H.
Kimura and O. Izumi, Kyoto, Japan, May 19-22,1980, pp. 1937-1945.
242. Setoguchi, Masahiko, "Pollution Prevention for Titanium Tetrachloride Plant," Titanium '80 Science
and Technology: Proceedings of the Fourth International Conference on Titanium, ed. H. Kimura
and O. Izumi, Kyoto, Japan, May 19-22,1980, pp. 1947-1949. .
243. Ghosh, Arindam and Ashok M. Deshkar, "Vaccum Filtration of Waste Sludge Produced in a Titanium
Dioxide Plant," LAWPC Tech. Annual X. 1983, pp. 45-53.
Primary Zinc
244. Bhandari, L.M., "Characteristics of Zinc Smelting Industrial Waste and Simultaneous Removal of
Toxic Elements and Phosphates From It," Indian Journal of Environmental Health. Vol. 15, No. 3,
1973, pp. 236-242.
245. Welch, Gary E., "Disposal of Slag From the Electrothermic Zinc Smelter of St. Joe Minerals
Corporation," Solid Wastes: Origin. Collection. Processing, and Disposal. CL. Mantell (ed.), 1975,
pp. 1085-1090.
246. PEDCo Environmental, Inc., Industrial Process Profiles for Environmental Use. Chapter 28: Primary
Zinc Industry. EPA-600/2-80-169, Environmental Protection Technology Series, Industrial
Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency, July 1980.
Multisector Documents
247. Chamberlin, P.D., D J. Dinneberg, and R.M. Nadkarni, "Steps Outlined to Ensure Precious Metals
Miners Have Good Relationships With Their Refiners," Mining Engineering. VoL 38, No. 10, October
1986, pp. 959-962.
248. Chementator, "A New Process Could Clean Up Chlorinated Wastes at 1/3 to 1/2 the Cost," Chemical
Engineering. February 1989, p. 17.
249. Chementator, "Separating Oil-Water Emulsions by Electrocoagulation May Be Far Cheaper,"
Chemical Engineering. January 1989, p. 19.
250. Cushey, Mark A. and Edward S. Rubin, "Simplified Models of U.S. Acid Rain Control Costs,"
JAPCA. Vol. 38, No. 12, December 1988, pp. 1523-1527.
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B-5-16 Appendix B-5: List of Published Reports
251. Chementator, "Sewage Sludge + Kiln Dust = Agricultural Fertilizer," Chemical Engineering. October
10, 1988, p. 21.
252. Jones, Julian W, Thomas E. Emmel, and Bernard A. Laseke, "Performance/Cost Estimates for
Retrofitting Control Technologies at 12 Coal-Fired Power Plants," JAPCA. Vol. 38, No. 6, June 1988,
pp. 852-856.
253. Shaw, George B., John W. Norton, and Burton S. Middlebrooks, "Feasibility of Constructing a Waste-
to-energy Incinerator to Generate Electricity for a Colocated Wastewater Treatment Plant," Journal
WPCF. Vol. 58, No. 4, April 1986, pp. 267-271.
254. Tarquin, Anthony, and Sara Goodwin, "Conventional Water Process Costs Studied,"
WATER/Engineering & Management July 1984, pp. 24-27.
255. Chementator, "EPA Assesses This Decade's Pollution Control Cost at More than $700 Billion,"
Chemical Engineering. August 20, 1984, p. 20.
256. "Cheap Treatment for Paper-mill Effluent," Chemical Week. November 11, 1981, p. 41.
257. Vatavuk, William M., and Robert B. Neveril, "Estimating Costs of Air-pollution Control Systems, Part
XIV: Costs of Carbon Adsorbers," Chemical Engineering. January 24,1983, pp. 131-132.
258. Mininni, G., R. Passino, M. Santori, and L. Spinosa, "Sludge Dewatering in a Conventional Plant
With Phosphorus Removal -1: Analysis of Additional Costs," Water Research. Vol. 19, No. 2,1985,
pp. 143-149.
259. Newsfront, "A Casebook of Successful Waste-reduction Projects," Chemical Engineering. August 15,
1988, p. 37.
260. Huiatt, Jerry L., James E. Kerrigan, Perron A. Olson, and Gary L. Potter, Proceedings of a
Workshop. Cyanide From Mineral Processing. Salt Lake City, IJT, February 2-3, 1982.
261. Smith, Robert, Computer Assisted Preliminary Design for Drinking Water Treatment Process
Systems. EPA/600/2-86-007a, Water Engineering Research Laboratory, ORD, U.S. Environmental
Protection Agency, January 1986.
262. Baker, E.G., H.D. Freeman, and J.N. Hartley, Pacific Northwest Laboratory, Idaho Radionuclide
Exposure Study - Literature Review. PNL-6358, prepared for Office of Radiation Programs, U.S.
Environmental Protection Agency, October 1987.
263. "US Fails to Gain Ground In Water Pollution Effort," Chemical Marketing Reporter. February 20,
1989, pp. 7,16.
264. "Standards for Onshore Drilling Stipulated in new BLM Regulation," Inside Energy with Federal
Lands. November 21,1988, pp. 11-12.
265. Balcerek, Tom, "Pending Amendments to Clean Air Act Costly," American Metal Market. Vol. 96,
March 11,1988.
266. Barnes, R.A., G.S. Parkinson, and A.E. Smith, "The Costs and Benefits of Sulphur Oxide Control,"
Journal of the Air Pollution Control Association. \6l 33, No. 8, August 1983, pp. 737-741.
267. Hickey, John J. and William E. Wilson, Results of Deep-Well Injection Testing at Mulberry. Florida.
U.S. Geological Survey, Water-Resources Investigations, February 1982.
268. Owen, Thomas and Michael J. Humenick, "Cost Analysis of Water Pollution Control During In Situ
Production of Bitumen from Tar Sand," In Situ. 1986, pp. 145-174.
269. Mara, Duncan, "Waste Stabilization Ponds: Problems and Controversies," (no date), pp. 21-22.
270. Shamsuddin, M., "Metal Recovery from Scrap and Waste," Journal of Metals. February 1986, pp.
24-31.
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Appendix B-5: List of Published Reports B-5-17
271. Pollution Control Group, Department of Chemical Engineering, University of Natal, "Cost Factors
Involved in the Design of a Sizing/Desizing Treatment Plant," American Dvestuff Reporter. January
1989, pp. 37-42.
272. Gates, Kenneth M. and A.CK Caldwell, "Use of Byproduct Gypsum to Alleviate Soil Acidity," Soil
Science Society of America Journal. 1985, pp. 915-918.
273. Emery, J.J., "Utilization of Waste By-Products in Canadian Construction," Proceedings of the Sixth
Mineral Waste Utilization Symposium. Chicago, IL, May 2-3, 1978, pp. 36-43.
274. Collins, Robert J., "Construction Industry Efforts to Utilize Mining and Metallurgical Wastes,"
Proceedings of the Sixth Mineral Waste Utilization Symposium. Chicago, IL, May 2-3,1978, pp. 133-
143.
275. Higgins, Leo M. Ill, William H. Bauer, and Dodd S. Carr, "Utilization of Lead and Zinc Slags in
Ceramic Construction Products," Conservation & Recycling. Vol. 3, 1980, pp. 375-382.
276. "Wasteless Technology for Pollution Control," Chemical Weekly. Vol. 33, March 1, 1988, p. 63.
277. Young, D. Ray and Gerald Armstrong, "Cost Reduction in Sludge Processing with Innovative Sludge
Thickening Technology," Texas Civil Engineer. January 1989, pp. 13-19.
278. Opitz, Brian E., Michael E. Dodson, and R. Jeffrey Serne, Pacific Norhtwest Laboratory, Uranium
Mill Tailings Neutralization: Contaminant Complexation and Tailings Leaching Studies.
NUREG/CR-3906, PNL-5179, prepared for U.S. Nuclear Regulatory Commission, May 1985.
279. Panpanu, J.S., R J. Adler, M.B. Gorensek, and M.M. Menon, "Separation of Fine Particle Dispersions
Using Periodic Flows in a Spinning Coiled Tube," American Institute of Chemical Engineers Journal.
Vol. 32, 1986, pp. 798-808.
280. Gidley, James S. and William A. Sack, "Environmental Aspects of Waste Utilization in Construction,"
Journal of Environmental Engineering. December 1984, pp. 1117-1133.
281. Emery, JJ. and D.B. Matchett, "A Waste Management Strategy for Major Industries," Conservation
and Recycling. 1980, pp. 439-446.
282. Ettinger, William S., "Impacts of a Chemical Dust Suppressant/Soil Stabilizer on the Physical and
Biological Characteristics of a Stream," Journal of Soil and Water Conservation. March-April 1987,
pp. 111-114.
283. Wong, M.H., "Reclamation of Wastes Contaminated by Copper, Lead, and Zinc," Environmental
Management. 1986, pp. 707-713.
284. Ceilings, Ronald K., "Current and Potential Uses for Mining and Mineral Processing Wastes in
Canada: Standards," Journal of Testing and Evaluation. January 1984, pp. 46-50.
285. Clifton, James Roger, Paul W. Brown, and Geoffrey Frohnsdorff, "Uses of Waste Materials and By-
Products in Construction: Part I," Resource Recovery and Conservation. 1980, pp. 139-160.
286. Emery, JJ., "Utilization of Wastes and By-Products as Construction Materials in Canada,"
Conservation and Recycling. 1978, pp. 31-41.
287. Shamsuddin, M., "Metal Recovery from Scrap and Waste," Journal of Metals. February 1986, pp. 24-
31.
288. Ban, Thomas E., "Staged-electric Ironmaking Utilizing Solid Wastes of the Aluminum and Steel
Industries," Resources and Conservation. 1982, pp. 199-208.
289. Reddy, Ramana G., "Mineral Waste Treatment and Secondary Recovery," Journal of Metals. April
1986, pp. 49-55.
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B-5-18 Appendix B-5: List of Published Reports
290. Clifton, James Roger, Paul Wencil Brown, and Geoffrey Frohnsdorff, "Uses of Waste Materials and
By-Products in Construction: Part II," Resource Recovery and Conservation. Vol. 5, 1980, pp. 217-
228.
291. Miller, Jeffrey G., "Deep-Well Disposal: Theory, Practice, and Regulation," Hazardous Substances.
January 1986, pp. 14-19.
292. Klumpar, I.V, "Updated Capital Cost Estimation Factors," Process Economics International. Vol. VI,
Nos. 3 & 4, 1986, pp. 40-53.
293. Crisafulli, Tricia, "Operating Costs Running 50% Less at Inco Mine," American Metal Market. Vol.
94, June 12, 1986.
294. Weber, A. Scott, Jo Ann Silverstein, Joseph H Sherrard, Richard O. Mines, and Mark S. Kennedy,
"Activated Sludge," Journal of the Water Pollution Control Federation. June 1988, pp. 816-824.
295. Heinrich, Gerhard, "On the Utilization of Nickel Smelter Slags," CIM Bulletin. January 1989, pp. 87-
91.
296. Smith, R.A.H. and A.D. Bradshaw, "The Use of Metal Tolerant Plant Population for the Reclamation
of Metalliferous Wastes," Journal of Applied Ecology. 1979, pp. 595-612.
297. Semler, Charles E., "A Quick-Setting Wollastonite Phosphate Cement," American Ceramic Society
Bulletin. 1976, pp. 983-985.
298. Woods, Donald R., Susan J. Anderson, and Suzanne L. Norman, "Evaluation of Capital Cost Data:
Heat Exchangers," The Canadian Journal of Chemical Engineering. December 1976, pp. 469-488.
299. Reddy, Ramana G., "Metal, Mineral Waste Processing and Secondary Recovery," Journal of Metals.
April 1988, pp. 46-51.
300. Rampacek, Carl, "An Overview of Mining and Mineral Processing Waste as a Resource," Resources
and Conservation. 1982, pp. 75-86.
301. Vogely, William A., "The Economic Factors of Mineral Waste Utilization," Proceedings of the First
Mineral Waste Utilization Symposium. Chicago, IL, March 27-28,1968, pp. 7-19.
302. Lauer, Gerald J., "Some Effects of Metals on Aquatic Life," Proceedings of the First Mineral Waste
Utilization Symposium. Chicago, IL, March 27-28,1968, pp. 20-27.
303. Narin, Francis, "A Systems Approach to Mineral Waste Utilization," Proceedings of the First Mineral
Waste Utilization Symposium. Chicago, IL, March 27-28, 1968, pp. 28-37.
304. Kean, Karl C, "Utilization of Mine, Mill, and Smelter Wastes," Proceedings of the First Mineral
Waste Utilization Symposium. Chicago, IL, March 27-28,1968, pp. 138-141.
305. Rubchevskii, V.N., Yu. A. Chernyshov, and A.G. Belichenko, "Economic Efficiency of Construction
of Biochemical Waste Water Treatment Facilities," Control and Economics. 1987, pp. 46-47.
306. Miller, Richard H. and Robert J. Collins, Waste Materials as Potential Replacements for Highway
Aggregates. National Cooperative Highway Research Program Report 166, Transportation Research
Board, 1976.
307. Dayton, Stan and Daniel Jackson, Jr., 'Mining Program Aims at Growth Opportunities," Engineering
and Mining Journal. August 1974, pp. 63-74.
308. Mantle, E.C., "Advances in the Recovery of Waste Non-Ferrous Metals," Chemistry and Industry.
September 4,1976, pp. 716-720.
309. Ratter, E.G., "Waste Management in the Lead-Zinc Industry,' Proceedings of the Australian Waste
Management and Control Conference: Waste Management. Control. Recovery, and Reuse. 1974, pp.
167-170.
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Appendix B-5: List of Published Reports B-5-19
310. Linton, W.L., "The Control of Solid Waste, Dust Emission and Effluent in the Production of Non-
Ferrous Metals," Effluent Treatment in the-Process Industries (EFCE Publication Series No. 31) &
Institution of Chemical Engineers Symposium Series No. 77). 1983, pp. 13-24.
311. Leonard, Richard P., "Hazardous Solid Waste From Metallurgical Industries," Environmental Health
Perspectives. Vol. 27, 1978, pp. 251-260.
312. Collins, RJ. and R.H. Miller, Availability of Mining Wastes and Their Potential for Use as Highway
Material - Executive Summary. FHWA-RD-78-28, prepared for Federal Highway Administration,
September 1977.
313. Collins, RJ. and R.H. Miller, Availability of Mining Wastes and Their Potential for Use as Highway
Material - Volume I: Classification and Technical and Environmental Analysis. FHWA-RD-76-106,
prepared for Federal Highway Administration, May 1976.
314. Collins, RJ. and R.H. Miller, Availability of Mining Wastes and Their Potential for Use as Highway
Material - Volume II: Location of Mining and Metallurgical Wastes and Mining Industry Trends.
FHWA-RD-76-107, prepared for Federal Highway Administration, May 1976.
315. Collins, RJ. and R.H. Miller, Availability of Mining Wastes and Their Potential for Use as Highway
Material - Volume III: Annotated Bibliography. FHWA-RD-76-1Q8, prepared for Federal Highway
Administration, May 1976.
316. Muehlberg, P.E., J.T. Reding, B.P. Shepherd, Terry Parsons and Glynda E. Wilkins, Industrial Process
Profiles for Environmental Use: Chapter 22. The Phosphate Rock and Basic Fertilizer Materials
Industry. EPA-600/2-77-023v, Environmental Protection Technology Series, prepared for Industrial
Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency, February 1977.
317. Richards, AW., "Practical Implications of the Physical Chemistry of Zinc-Lead Blast Furnace Slags,"
Canadian Metallurgical Quarterly. Vol. 20, No. 2, 1981, pp. 145-151.
318. Spendlove, Max J., Bureau of Mines Research on Resource Recovery: Reclamation. Utilization.
Disposal, and Stabilization. Information Circular 8750, Bureau of Mines, U.S. Department of Interior,
1977.
319. Environmental Systems Department, Calspan Corporation, Heavy Metal Pollution from Spillage at
Ore Smelters and Mills. EPA-600/2-77-171, Environmental Protection Technology Series, Industrial
Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency; August 1977.
320. PEI Associates, Inc., Overview of Solid Waste Generation. Management, and Chemical
Characteristics: Primary Antimony. Magnesium. Tin, and Titanium Smelting and Refining Industries.
Industrial Environmental Research Laboratory, ORD, U.S. Environmental Protection Agency,
December 1984.
321. Taylor, John C and Alan D. Zunkel, "Environmental Challenges for the Lead-Zinc Industry," Journal
of Metals. August 1988, pp. 27-30.
322. Williams, R., R. Shamel, K. Hallock, B. Stangle, and S. Blair, Economic Assessment of Potential'
Hazardous Waste Control Guidelines for the Inorganic Chemicals Industry. EPA/530/SW-134C, U.S.
Environmental Protection Agency, October 1976.
323. Ayer, Franklin A. (compiler) Research Triangle Institute, Proceedings: Symposium on Flue Gas
Desulfurization - Houston. October 1980 - Volume 2. EPA-600/9-811-019b, Industrial Environmental
Research Laboratory, ORD, U.S. Environmental Protection Agency, April 1981. (selected parts)
324. Watson, A.P., E.L. Etnier, and L.M. McDowell-Boyer, Radium-226 in Drinking Water and Terrestrial
Food Chains: A Review of Parameters and an Estimate of Potential Exposure and Dose. ORNL/TM-
8597, prepared by Oak Ridge National Laboratory for the Florida Institute of Phosphate Research,
April 1983.
325. Harley, John H., "Radioactivity in Building Materials," (source unknown), pp. 332-343.
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B-5-20 Appendix B-5: List of Published Reports
326. Kolb, W. and H. Schmier, "Building Material Induced Radiation Exposure of the Population," (source
unknown), pp. 344-350.
327. Michel, Jacqueline and Mark J. Jordana, "Nationwide Distribution of Ra-228, Ra-226, Rn-222, and.
U in Groundwater," Radon in Ground Water. NWWA, pp. 227-240.
328. Teknekron Research, Inc., Primary Pyrometallurgical Extraction Process fib Which ESHAP's Mav
Apply) Draft. Partial, and Supplemental Background Information Document - Information Base
(Including Sources and Emission Ratest for the Evaluation and Control of Radioaaive Materials to
Ambient Air. Interim Report, Volume I, Submitted to ORP, U.S. Environmental Protection Agency,
Docket Number A-79-11, May 1981.
329. Nathwani, Jatin S. and Colin R. Phillips, "Adsorption of 226Ra By Soils," Chemosphere No. 5. pp.
285-291.
330. "Radiation Exposures Due to the Exploitation of Phosphate Rock," (source unknown), pp. 113-140.
331. Guimond, Richard J. and Samuel T. Windham, The Radiological Evaluation of Structures
constructed on Phosphate-Related Land," ORP, U.S. Environmental Protection Agency, (no date).
332. Horton, TR., A Preliminary Assessment of Radiation Doses Due to Consumption of Food Associated
with Phosphate Reclaimed Land and Ore Byproduct Usage. (Draft), September 1978.
333. Utah Division of Environmental Health, Bureau of Water Pollution Control, 1989. Statement of
Basis for Utah Pollutant Discharge Elimination System Permit No. UT0000779.
334. CDM Federal Programs Corporation, State Regulation of Solid Wastes from the Extraction.
Beneficiation. and Processing of Non-Fuel Ores and Mineral, done for U.S. EPA Office of Solid
Waste, Document Control No. T1142-ROO-DR-DELC-1, June 2, 1989.
335. State of North Carolina, Permit No. WQ0001492, Department of Environment, Health, and Natural
Resources, January 4,1990.
336. State of North Carolina, Permit No. WQ0001487, Department of Environment, Health, and Natural
Resources, January 4,1990.
337. Company responses to EPA's National Survey of Solid Wastes from Mineral Processing Facilities.
conducted in 1989.
338. Industry submittals from 228 facilities in response to EPA's request under authority of RCRA Section
3007 for data on mineral processing waste composition.
339. ICF Incorporated, 1989, Reports of visits to 28 mineral processing facilities in June and July of 1989.
340. EPA, 1990, "Waste Characterization Data for 20 Mineral Processing Wastes," January 11,1990.
341. EPA, 1989, "Waste Characterization Data for Selected Mineral Processing Wastes,* Memorandum
from Bob Hall, OSW to the Files.
342. Versar, 1989, "Organic and General Chemistry Data for the Mineral Mining Project," Memorandum
from Justine Alchowiak to Bob Hall, EPA, August 30,1989.
343. Versar, 1990, "Analytical Results for Mineral Mining," Memorandum from Justine Alchowiak to Bob
Hall, EPA, January 8,1990.
344. PEI Associates, Inc., 1986, "Evaluation of Waste Management for Phosphate Processing," Prepared
for the Office of Research and Development, EPA, August 1986.
345. PEDCo Environmental Inc., 1984, "Overview of Solid Waste Generation, Management, and Chemical
Characteristics in the Primary Copper Smelting and Refining Industry," Prepared for the Office of
Research and Development, EPA, October 1984.
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Appendix B-5: List of Published Reports B-5-21
346. PEI Associates, Inc., 1984, "Overview of Solid Waste Generation, Management, and Chemical
Characteristics in the Primary Zinc Smelting and Refining Industry," Prepared for the Office of
Research and Development, EPA, December 1984.
347. PEI Associates, Inc., 1984, "Overview of Solid Waste Generation, Management, and Chemical
Characteristics in the Primary Lead Smelting and Refining Industry," Prepared for the Office of
Research and Development, EPA, November 1984.
348. PEI Associates, Inc., 1984, "Overview of Solid Waste Generation, Management, and Chemical
Characteristics in the Primary Antimony, Magnesium, Tin, and Titanium Smelting and Refining
Industries," Prepared for the Office of Research and Development, EPA, December 1984.
~ 49. EPA, 1990, "Idaho Radionuclide Study," Office of Radiation Programs, April 1990, EPA/520/6-90/008.
350. EPA, 1989, "NESHAPS for Radionuclides, Environmental Impact Statement, Background Information
Document -- Volume 2, Risk Assessments," Office of Radiation Programs, September 1989,
EPA/520/1-89-006-1.
351. EPA, 1979, "Environmental and Resource Conservation Considerations of Steel Industry Solid
Wastes," Office of Research and Development, EPA-600/2-79-074.
352. EPA, 1989, "Interim Final Guidance for Soil Ingestion Rates," Memorandum from J. Winston Porter,
Assistant Administrator of the Office of Solid Waste and Emergency Response, to Regional
Administrators, January 27, 1989.
353. ICF, Incorporated, 1986, Development of Soil: Water Distribution Coefficients for LLM Inorganic
Chemicals - Draft," June 12, 1986.
354. Harris, L.W., 1989, Public Comment on the National Priority Listing of Monsanto Chemical
Company's Soda Spring facility (with photographs), June 26, 1989.
-------
Appendix C
Risk Assessment Criteria and Model
-------
Appendix C-1
Risk Assessment Screening Criteria
-------
Appendix C-1
Risk Assessment Screening Criteria
As described in Section 2.2.2 of Volume II of this report, EPA began its risk assessment of mineral
processing wastes by assessing the intrinsic hazard of each waste stream. The Agency assessed intrinsic hazard
by comparing the concentrations of chemical and radioactive contaminants in each waste and waste leachate
to a series of conservative screening criteria. Concentrations above the screening criteria were interpreted as
an indication that the wastes conceivably could pose risk to human health or the environment under a set of
very conservative, hypothetical release and exposure conditions -- exceedances of the criteria should not, in
isolation, be interpreted as proof of hazard. If any sample of a waste from any facility contained a contaminant
concentration in excess of a screening criterion, EPA used that as a basis for proceeding to the next step of
the assessment to evaluate the site-specific factors that influence the waste's risk in more detail. Contaminants
that never exceeded a screening criterion were dropped from further analysis.
Section 2.2.2 describes the rationale and process for developing the different categories of screening
criteria. This appendix lists the specific numerical values that were used as criteria, as well as the regulatory
or lexicological benchmarks upon which the criteria were based. In particular, the appendix provides the
following four exhibits:
1. Exhibit C-l-1, Human Health Screening Criteria for Comparison to Liquid/Leachate Samples;
2. Exhibit C-l-2, Resource Damage Screening Criteria for Comparison to Liquid/Leachate
Samples;
3. Exhibit C-1-3, Aquatic Ecological Screening Criteria for Comparison to Liquid/Leachate
Samples; and
4. Exhibit C-l-4, Screening Criteria for Comparison to Solid Samples.
-------
C-1 -2 Appendix C-1: Risk Assessment Screening Criteria
Exhibit C-1-1
Human Health Screening Criteria
for Comparison to LJquid/Leachate Samples
Constituent
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
CaoitUtjrn
Chloride
Chromium (VI)
Cobalt
Copper
Fluoride
Gross alpha
Gross beta
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Nitrite
Nitrate
PH
Phosphate (Total)
Phosphorus
Radlum-226
Selenium
Silver
Sulfate
Suspended solids
Thallium
Thorium-232
Uranium-238
Vanadium
Zinc
Drinking Water Benchmark*
Cancer
Benchmark*"
(AQ/L)
O2
-
1.6pO/L
9.1 pCtf-
1.5pCi/L
Noncancer
Benchmark0"*
(AO/L)
14
35
1,800
tao
3,200
ia
tao
1.300
2,100
21
7,000
1O
700
3,500
35,000
110
«O
2.5
250
7.000
Associated
Noncancer Effect
Cardiac effects
Dermal effect*
High blood pressure
Decreased growth
Adv. effect to repro. organs
Renal effects
Kidney, itvar damage*4
Gl Irrigation
Dental fluorosis
Neurotoxicfty
CMS effects
CNS effects
Methemoglobenemia
Methemoglobenemia
Dermal, neuro. effects
Skin dJscotoration
CNS effects'*
Uver, bone marrow damage*9
Hematological effects
Human Hearth
Screening Criterion
btg/L)
_(e>
140
2
18,000
1,800
32,000
180
-
1,800
-
13,000
21,000
-
-
-
210
: -
70,000
100
-
7,000
35,000
350,000
-
-
-
16pCi/L
1,100
1,100
-
-
25
sipcvi.
15pCI/L
2,500
70,000
(a) Concentrations represent a lifetime cancer risk of 1x10 . The arsenic concentration was derived from the cancer slope
factor presented in the Integrated Risk Information System (IRIS). The radionuclide concentrations were estimated based
on cancer slope factors developed by EPA's Office of Radiation Programs for inclusion in the Health Effects Assessment
Summary Tables (HEAST).
(b) Derived from chronic reference doses (RfDs) presented in IRIS, with the exception of lead. For lead, an RfD of 0.0006
mg/kg-day was independently derived based on available toxicologies! data.
(c) No screening criterion used because of lack of toxicologies! benchmarks.
(d) Acute effects (no chronic effects at these coneentratiorw).
-------
Appendix C-1: Risk Assessment Screening Criteria C-1 -3
Exhibit C-1 -2
Resource Damage Screening Criteria for Comparison
to LJquid/Leachate Samples
Constituent
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Chloride
Chromium(V$
Cobalt
Copper
Fluoride
Grow alpha
Qross beta
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Nitrite
Nitrate
PH
PhosphatafTotal)
Phosphorus
Radiura-226
Selenium
Silver
Sulfate
Sufpftntted flottcte
Thallium
Thofiura-232
Uranium-238
Vanadium
Zinc
Benchmark
Oifl/L)
5,000
45,000
50
1,000
1.2
750
10
250,000
50
50
1,300
4,000
ISpCI/L
SOpCiA.
300
5
50
2
10
200
1,000
10,000
6.54.5
SpClfl.
10
50
250.000
46
100
5,000
Basis tor Benchmark
Continuous irrigation guidew
AWQC for fish ingestion""
Primary MCLW
Primary MCL
AWQC for fish {ngestion
Continuous irrigation guide
Primary MCL
Secondary MCL
Primary MCL
Continuous irrigation guide
Secondary MCL (proposed}
Primary MCL
Prtnwn/MCLw
Primary MCL(d)
Secondary MCX
Primary MCL (proposed)
Secondary MCL
Primary MCL {proposed}
Continuous irrigation guide
Continuous Irrigation guide
Primary MCL
Primary UCL
Secondary MCL
Primary MCL"
Primary MCL
Primary MCL
Secondary MCL
AWQC for fish ingestion
Continuous irrigation guide
Secondajy HCt : :
Resource Damage
Screening Criterion (ug/L)
50,000
4,500,000
500
10,000
120
7,500
100
2,500,000
500
500
13,000
40,000
150pCUL
500pCi/L
3>000
50
J&
500
20
100
2.000
10,000
100,000
6.54.5
-
-
SQpCVL
100
500
Z500.000
: —
4,600
-
-
1.000
50,000
(a) Maximum concentratJona recommended by the National Academy of Science* in Water Quality Criteria-1872.' Theeecon-
centratlons are generally set at levels lees than the concentrations that are toxic to sensitive plsrrts when grown in sandy soils.
(b) Ambient Water Quality Criteria (AWQC), as taken from EPA chemteai-epeciflc eource documento, designed to protect against
adverse human health effects caused by the ingestion of fish. For beryllium, the benchmark presented here is designed to
limit cancer risks to a level of 1x10*.
(c) Drinking water maximum contaminant level (MCL).
(d) The MCL for gross alpha radiation excludes radon and uranium. No MCL for gross beta radiation has been issued; however,
compliance with 40 CFR 141.16 may be assumed if gross beta concentrations are less than 50 pCi/L The MCL for radium
is 5 pCi/L for combined radium-226 and radium-228.
(e) No screening criterion used because of lack of relevant benchmarks.
-------
C-1 -4 Appendix C-1: Risk Assessment Screening Crtterla
Exhibit C-1 -3
Aquatic Ecological Screening Criteria
for Comparison to Liquid/Leachate Samples
Constituent
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Chloride
Chromium{V§
Cobalt
Copper
Fluoride
Grow sjph*
Qross beta
'. Iran
Lead
Magnesium^
Manganese
Mercury
Molybdenum
Nickel
Nitrite
Nitrate
pH
Phosphate (Total)
Phosphorus
Radium-226
Selenium
Silver
Sulfate**1
Suspended solids
Thallium
Thorium-232
IbteJ Dissolved Solids"
Uranium-238
Vanadium
Zinc
Benchmark
(WJ/L)
sr
1,600
13
50,000
5,3
5,000
1.1
230,000
t1
Z9
14X90
3.2
1.000
O.OT2
8.3
60
90,000
6.M
25-100
0.!
5
0.12
25,000
40
5,000,000
1,280
W
Basis for Benchmark
Freshwater chronic AWQCW
Freshwater chronic AWQC
Saltwater chronic AWQC**
Freshwater chronic guide14
Freshwater chronic AWQC
Saltwater chronic guide
Freshwater chronic AWQC
Freshwater chronic AWQC
Freshwater chronic AWQC
Saltwater cnronte AWQC
Freshwater chronic AWQC
Freshwater chronic AWQC
Freshwater chronic guide
_
Saltwater chronic AWQC
Freshwater chronic guide
Freshwater chronic guide
freshwater chronic AWQC
Freshwater chronic guide"
Saltwater chronic AWQC
Frefnyrater <$nronic AsnfQQ
Freshwater chronic AWQC
Freshwater chronic guide
Freshwater chronte AWQC
Freshwater chronic guide
Freshwater acute guide
Aquatic Ecological
Screening Criterion Otg/L)
8,700
160,000
1,300
5,000,000
930
500,000
110
23,000,000
1,100
_w>
290
-
-
-
100,000
320
-
100,000
12
-
830
6,000
9,000,000
6.5-8
2,500-10,000
10
-
500
12
.
2,500,000
4)000
-
500,000,000
-
128,000
8,600
(a) Ambient Water Quality Criteria (AWQC), as taken from EPA chemical-specific source documents, designed to protect
freshwater organisms against harmful chronic exposures.
(b) AWQC, as taken from EPA chemical-specific source documents, designed to protect saltwater organisms against harmful
chronic exposures.
(c) Not official AWQC, but independently developed based on the toxteotogical literature.
(d) No screening criterion used because of lack of toxicologies) benchmarks and data.
(e) Total dissolved solids figure for magnesium plus sulfats.
(f) Benchmarks for phosphate are 25 *g/L within a lake or reservoir, 50 cg/L In any stream at the point where it enters a lake
or reservoir, and 100 *g/L in streams or other flowing waters not discharging directly to lakes or impoundments.
-------
Exhibit C-1-4
Screening Criteria for Comparison to Solid Samples
Conatltuanta
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Chloride
ChromHim(VD
CobaK
Copper
Fluoride
Oroaa alpha
Qroaabata
Iron
Lead
Magnesium
Manganese
Marcury
Molybdenum
Nickel
Nitrite
Nitrate
pH
Phosphate (Total)
Phosphorus
Radium-226
Selenium
Silver
Soil mgaalton Screening Criteria.
• Cancer
Benchmark'**
(MO/O)
4
Noncancar
Benchmark*14
(MO/O)
280
7W
35.000
3,900
63,000
390
3,900
25,flOO
42,000
420
140,000
210
14.000
70,000
700,000
2.100
2,100
Aaaoclalad Noncancar Effect
Cardiac affects
Parma) anaoto
Ineraaaad blood pressure
Dacraaaad growth
RaneJ afwcui
Kidney, Ifvar damage**
Ql irritation
Dental fluoroste
Naurotoxlctty
CNSaffacto
CNSaffaota
Dacraaaad weight
Mathemoglobanamla
Mothamoglobenamla
Dermal, neurological effects
Skin discoloration
ParticuUrta Inhalation Screening Crttarla"*
Cancer
Benchmark'"1
0*0/0)
14
84
115
17
833
134 pCi/gw
Noncancar
Benchmark0''
(MO/0)
7,000
21,000
80
Associated Noncancar Effect
Fetotoxlcity
CNS effects
Dermatitis, Gl disturbance
a
ST
O
_*
5
•
>
I
O
I
o
-------
C-1-6 Appendix C-1: Risk Assessment Screening Criteria
(0
£
a
I
o
(0
?2
s §
o «
:i
(\ O
°0
ii
O
9
i
It
a 2 s i
-------
Appendix C-1: Risk Assessment Screening Criteria C-1 -7
-------
Appendix C-2
Summary of MMSOILS Model
-------
Appendix C-2
Summary of MMSOILS Model
Introduction
MMSOILS is a multimedia exposure and risk estimation model that was originally developed by
EPA's Office of Research and Development (ORD). The model is a screening tool designed to assist EPA
in setting priorities for hazardous waste management.
MMSOILS was designed to estimate exposures and health risks associated with the release and
subsequent fate and transport of chemicals from contaminated soils. The four basic functions of the
multimedia methodology are to:
(1) Estimate chemical release rates from the soil into various environmental media (air, ground water,
surface water, food sources), based on chemical properties and land use at the site;
(2) Estimate the chemical concentration at exposure points in each environmental media considered,
based on the chemical release rate and the proximity to exposed populations;
(3) Estimate human exposures through inhalation, ingestion, and absorption based on the chemical
concentration at exposure points and assumptions regarding human intake levels; and
(4) Estimate the potential health risk based on toxicity data for the specific chemical, based on toxicity
data for the chemical and the estimated human exposures at exposure points.
MMSOILS has been used for comparison with an EPA dioxin exposure assessment document (EPA
1988), with favorable results. It also has undergone extensive peer review by several offices of EPA and
members of the academic community. The model documentation (ICF Technology, Inc. 1989) provides more
detailed description of MMSOILS.
Adaptations for the Mineral Processing Waste Risk Assessment
The mineral processing waste risk assessment required modeling of multiple chemicals released from
a variety of waste containment units, not just contaminated soil. MMSOILS was identified as an appropriate
model for the task, but three major model modifications were required.
First, algorithms for predicting contaminant releases from waste management units such as waste piles,
landfills, surface impoundments, and injection wells, were added. As part of this change, the water balance
component, which accounts for precipitation, evapotranspiration, and recharge, was revised to accommodate
changes in the waste management units with time, such as the installation of a cap on a landfill, or the gradual
failure of a liner. MMSOILS now allows the user to specify a cover and liner design, and the magnitude and
timing of waste containment failure. Cover designs include vegetative, clay, and RCRA cap. Liner designs
include unlined, clay, single synthetic, composite (clay, membrane, and collection system), and a double liner
that meets minimum technology requirements of HSWA Section 3004(o). The user can specify up to five
independent failure events throughout the simulation period.
Second, a selection of leachate quality algorithms was added. While the liner/cover design and
failure/release components of the model estimate the quantity of leachate released each year from a waste
management unit, the leachate quality algorithms estimate the contaminant concentrations in the waste
leachate. These algorithms are dependent upon the waste management unit chosen. There are three
mathematical approaches available for waste piles, landfills, and surface impoundments. As a matter of
practice in the mineral processing waste risk assessment, however, leachate quality was modeled as steady-state
contaminant concentrations that equal the median concentrations measured in extraction procedure leach tests
(as discussed in Chapter 2 of this report).
-------
C-2-2 Appendix C-2: Summary of MMSOILS Model
Third, MMSOILS was expanded to process multiple chemicals. Concentrations and resulting risks
of individual contaminants can be calculated for each desired pathway, and an overall risk can be summed
across constituents.
Overview of Major Release and Transport Modules
MMSOILS is divided into five distinct transport pathways: atmospheric, surface water, ground water,
soil erosion, and food chain bio-accumulation.
The Atmospheric Pathway
The atmospheric pathway is simulated if the potential for airborne releases exists at the site. The
atmospheric pathway component of the model considers the release of contaminants from the site in the form
of vapors and fugitive dust emissions from wind erosion and mechanical disturbances (however, with the
exception of the coal gasification wastes, only dust releases were relevant for the mineral processing waste risk
assessment). Once the contaminant is in the atmosphere, it is transported by wind and dispersed due to
turbulence in the flow. MMSOILS represents the following processes: volatilization from soils, volatilization
from a water body, paniculate emissions due to wind erosion and mechanical disturbances, atmospheric
transport and dispersion, and atmospheric deposition.
The equation used in MMSOILS for estimating the release of windblown dust assumes that there is
an "unlimited reservoir" of credible particles. This equation (adapted from EPA 1985) is an empirical
relationship of field and climatic factors that was developed based on field measurements of dust releases from
sandy agricultural soils. Therefore, application of this release equation to many of the mineral processing
wastes studied in this report is very conservative (i.e., it tends to overpredict releases). Many of the mineral
processing wastes actually contain a "limited reservoir" of erodible material, consisting of a mixture of erodible
and non-erodible elements such as large particles or fragments on the surface. These non-erodible elements
consume pan of the shear stress of the wind that otherwise would be transferred to erodible particles.
The Surface Water Pathway
The surface water pathway needs to be simulated if there is a potential for contaminants to leave the
site via run-off into surface water or discharge of affected ground water. The surface water pathway
component of the model evaluates contaminants entering one of two types of receiving water bodies, a
stream/river or a small lake. For contaminants entering a small lake, the source term is the contaminated bed
sediments resulting from the erosion of contaminated particles (either waste material or soil) from an adjacent
waste site. The potential source terms incorporated in the model for contaminants entering a stream include
the erosion of contaminants adsorbed to the solid particles and the discharge of contaminated groundwater
into the stream. The potential source term of contaminant dissolved in surface run-off from the site entering
a stream or a lake is not addressed in the model. Once contaminants have reached the water body, a
concentration in the water is estimated by assuming that the contaminants are completely mixed in the water's
flow.
In the mineral processing waste risk assessment, EPAs surface water modeling considered only the
chronic (i.e., steady-state) loading of contaminants to surface waters. Monthly average precipitation rates and
annual average surface water flow rates were used as model inputs. The Agency did not model larger short-
term releases, such as those associated with large storms, that could result in higher contaminant
concentrations that last for shorter durations.
The Ground-Water Pathway
The ground-water pathway is simulated if there is a potential for contaminants to be transported
through the unsaturated and saturated ground-water systems. The ground-water pathway component of the
-------
Appendix C-2: Summary of MMSOILS Model C-2-3
model examines the net recharge, leaching of contaminants from the soil, transport through the partially
saturated zone, and contaminant transport/dispersion within an aquifer. Recharge is calculated using a yearly
water balance, which adds system inputs (such as precipitation and irrigation) and subtracts outputs (such as
run-off and evapo-transpiration). Landfills, waste piles, and surface impoundments each have three options
available for calculating contaminant leaching. Flow through the partially saturated zone is assumed to be
steady state, and one dimensional. The fate and transport of a contaminant in an aquifer is estimated based
on a quasi-analytical solution to the advection dispersion equation incorporating retardation and first order
decay.
The Soil Erosion Pathway
The soil erosion pathway is analyzed if there is a potential for contaminated soil to be eroded off-site
to potential exposure points. The soil erosion pathway component of the model is used to evaluate
contaminant movement to off-site soils though two mechanisms: soil erosion and atmospheric deposition.
Although atmospheric deposition is not related to soil erosion processes, the effect of atmospheric deposition
is included at this point in the model since it is a mechanism by which off-site soils may become contaminated.
MMSOILS represents soil erosion from a site, delivery fraction of eroded soil and mixing with off-site soils,
and soil contamination due to atmospheric deposition.
The Food Chain Pathway
The food chain bio-accumulation pathway needs to be simulated if there exists a potential for
contaminants to enter the food chain. The food chain bioaccumulation pathway component of the model uses
the transport of contaminants from the site via other environmental transport pathways as the source term(s).
Examples of environmental transport pathways that may serve as the source terms for the food chain pathway
include atmospheric transport and deposition, soil erosion, and migration within ground-water and subsequent
use for irrigation. Based on these source terms, the food chain pathway component examines the accumulation
of a chemical within fish, terrestrial plants, and cattle. Simple representations of bioaccumulation using
bioconcentration factors and transfer factors are used in MMSOILS. The bioconcentration factors are used
to represent the partitioning of a chemical between: (1) water and fish, (2) edible parts of terrestrial plants
and soil, and (3) root vegetables and soil moisture. The transfer factors are used to represent the uptake of
chemical by animals as a function of the mass of chemical ingested in feed and water.
References
ICF Technology, Inc. 1989. Methodology for Estimating Multimedia Exposures to Soil Contamination.
Prepared for U.S. EPA Exposure Assessment Group, Office of Health and Environmental
Assessment, Office of Research and Development, July, 1989.
U.S. EPA. 1988. Exposure Factors Handbook, Draft Report Office of Health and Environmental
Assessment, Exposure Assessment Group, U.S. Environmental Protection Agency, Washington, D.C,
EPA/600/6-88/005a.
U.S. EPA. 1985. Rapid Assessment of Exposure to Paniculate Emissions from Surface Contamination Sites.
Office of Health and Environmental Assessment, U.S. Environmental Protection Agency, Washington,
D.C, EPA/600/8-85/002.
-------
Appendix D
Existing Regulatory Controls
-------
Appendix D-1
Existing Federal Regulatory Controls
Addressing Mineral Processing Wastes
-------
Appendix D-1
Existing Federal Regulatory Controls
Addressing Mineral Processing Wastes
1. Applicable Federal Regulations
While temporarily excluding all "[sjolid waste from the extraction, beneficiation, and processing of
ores and minerals" from regulation as hazardous waste under RCRA Subtitle C provisions, the 1980 Bevill
amendment did not preclude their regulation under "other provisions of federal or state law...." This includes
their current regulation under Subtitle D of RCRA and a variety of other federal and state air quality, water
quality, and solid and hazardous waste management requirements. Pending development of a RCRA
Subtitle D program that addresses mining wastes, EPA has stated its intention to use Section 7003 of RCRA
and Sections 104 and 106 of CERCLA "to protect against substantial threats and imminent hazards" (51 FR
244%). These provisions are mentioned under the discussions of RCRA and CERCLA, below.
Legal requirements vary, depending on the waste(s) or waste constituent involved, and the ownership
- public or private -- of the land involved. This appendix provides an overview of potentially applicable
federal laws, and the provisions that relate to the disposition of ore processing wastes.
2. Summary of Federal Laws and Regulations
There are several federal statutes that directly and indirectly affect the disposition of mineral
processing wastes. The key laws and responsible agencies are listed in Exhibit D-l-1. The important
provisions of these federal laws and their associated regulations as they relate to the management and disposal
of special wastes from mineral processing are summarized below.
3. Hazardous Waste
RCRA Subtitle C
In 1976, Congress enacted the Resource Conservation and Recovery Act (RCRA), which established
comprehensive requirements for the management of solid and hazardous wastes. Specific requirements for
hazardous wastes are found in Subtitle C of RCRA. Subtitle C provides a statutory framework for tracking
all hazardous and toxic wastes from "cradle to grave," that is, from their generation to their final disposal,
destruction, or recycling.
Pursuant to regulations issued by EPA (40 CFR Part 261), solid wastes which meet EPA hazardous
waste criteria with respect to "toxicity, persistence, degradability in nature, potential for accumulation in tissue,
and other related factors such as flammability, corrosiveness..." [Section 3001(a)j are subject to the statute's
labeling, storage, transportation, and disposal requirements.
Generally, some mineral processing solid wastes would otherwise qualify as hazardous wastes under
RCRA. However, pursuant to the statute's provisions under Section 3001(b)(3)(A)(ii), "(sjolid waste from
the extraction, beneficiation, and processing of ores and minerals, including phosphate rock and overburden
from the mining of uranium ore" are conditionally exempt from regulation under Subtitle C. EPA may
respond to a waste management situation that presents "an imminent and substantial endangerment to health
or the environment" under the authority of Section 7003 of RCRA. Actions sanctioned by Section 7003
include filing suit on behalf of the United States to order the violator to stop the activity, as well as the
-------
D-1-2 Appendix D-1: Existing Federal Regulatory Controls
Exhibit D-1-1
Federal Laws Applicable to Mineral Extraction,
Beneficiation, and Processing Wastes
Number
642 USC 6901 -€991 1
42 USC 9601-9675
33 USC 1251-1376
42USC300WOOJ-11
42 USC 7401-7641
42 USC 4341
43 USC 1701
Statute
The Resource Conservation and Recovery Act of
1976
-------
Appendix D-1: Existing Federal Regulatory Controls D-1 -3
situations at mineral production sites if required (51 FR 244%). In such situations, EPA can proceed with
necessary containment or removal actions. Where, conditions allow, the Agency can also undertake more
detailed remedial investigation and feasibility studies of abandoned or inactive waste sites necessary for the
design and execution of long term remedial actions. Section 106 provides authority for orders necessary to
protect public health and welfare and the environment and provides enforcement authority as well.
In those situations where responsible panics that can respond "properly and promptly" can be
identified, EPA is authorized to establish what remedial actions are required and to oversee the responsible
parties' cleanup efforts. In all cases, the owners and/or other responsible parties are liable for the costs of
cleaning up the hazardous waste problem, and for correcting damages to affected natural resources
(Section 107).
Under the law, EPA is required to establish and periodically update a National Contingency Plan
(NCP, Section 105) which includes, among other things:
[Cjriteria for determining priorities among releases or threatened releases
throughout the United States for the purposes of taking remedial action and,
to the extent practicable taking into account the potential urgency of such
action, for the purpose of taking removal action. Criteria and priorities...shall
be based upon relative risk or danger to public health or welfare or the
environment...taking into account to the extent possible the population at risk,
the hazard potential of the hazardous substances at such facilities, the potential
for contamination of drinking water supplies, the potential for direct human
contact, the potential for destruction of sensitive ecosystems, the damage to
natural resources which may affect the human food chain...the contamination
or potential contamination of the ambient air...[Section 105 (a)(8)(A)].
These criteria have been incorporated into a hazard ranking system (MRS) which is used to evaluate
uncontrolled hazardous waste sites around the country, and to rank them according to degree of overall
hazard. Sites that receive HRS scores greater than 28.5 are listed on the National Priorities List (NPL) which
makes them eligible for federal funding of additional remedial response activities.
Pursuant to the amendments to CERCLA - the Superfund Amendments and Reauthorization Act
of 1986 (SARA) - EPA must further revise the NCP to "assure, to the maximum extent feasible, that the
hazard ranking system accurately assesses the relative degree of risk to human health and the environment
posed by sites and facilities subject to review" [Section 105(c)]. SARA also requires that, pending revision of
the HRS, the addition of any uncontrolled hazardous waste sites containing "significant quantities" of mining
wastes - i.e., special study wastes under RCRA Section 3001(b)(3)(A) (including wastes from materials
generated from the extraction, beneficiation, and processing of ores and minerals), or other special study
wastes -- to the NPL must take into account the following factors:
(1) The extent to which the hazard ranking system score for the facility is
affected by the presence of any special study waste at, or any release from, such
facility.
(2) Available information as to the quantity, toxicity, and concentration of
hazardous substances that are constituents of any special study waste at, or
released from such facility, the extent of or potential for release of such
hazardous constituents, the exposure or potential exposure to human
population and the environment, and the degree of hazard to human health or
the environment posed by the release of such hazardous constituents at such
facility. This subparagraph refers only to available or actual concentrations of
hazardous substances and not to the total quantity of special study waste at
such facility [Section 105(g)(2)].
-------
0-1 -4 Appendix D-1: Existing Federal Regulatory Controls
A proposed rule modifying the Hazard Ranking System was published in the Federal Register in
December, 1988, and is being finalized at this time.
The SARA legislation also requires that for facilities at which hazardous wastes are left on-site, the
remedial cleanup plan must ensure that all "legally applicable" federal and state standards that may exist for
the hazardous substances in question are achieved [Section 121(d)(2)(A)].
4. Solid Waste
RCRA Subtitle D
Non-hazardous solid waste is regulated under Subtitle D of RCRA. Ore and mineral extraction,
beneficiation, and processing operations generally involve the generation, transport, storage, treatment, and
disposal of a wide variety of solid wastes including; overburden, waste rock, tailings, lubricants, solvents,
chemical reagents, refuse, and sewage.
Wastes generated from the extraction, beneficiation, and processing of ores and minerals (i.e. hard-
rock, non-fuel mining operations) were temporarily excluded, pending further study, from regulation under
the RCRA Subtitle C hazardous waste program by Section 3001 of RCRA (Le., the Bevill exclusion) in 1980.
Following the release of a Report to Congress in 1985, EPA made a regulatory determination in 1986 (51 FR
244%) that all of the wastes addressed by the 1985 Report to Congress would be regulated under Subtitle D
of RCRA rather than Subtitle C because of the relatively large volume, low hazard nature of those wastes.
EPA determined further that it would develop a new program under Subtitle D that would be flexible, site-
specific, risk-based, and tailored otherwise to address these mining wastes specifically, rather than relying on
existing Subtitle D programs. EPA is in the early stages of developing such a regulatory program and has
included one possible form of a risk-based, tailored, regulatory program for mineral industry wastes in this
report for analytical purposes (see Appendix E-2).
While there is not yet a federal program in place to address mineral industry wastes under Subtitle D,
many states have developed Subtitle D programs for future EPA approval. While desirable, the adoption of
a state solid waste program which meets minimum requirements specified by the Act is not mandatory. If a
state refuses to adopt and enforce its own solid waste management program, EPA currently has no statutory
authority to adopt or enforce a federal program in lieu of the state's; it can only withhold funds and technical
expertise from the state. Eight states do not as yet have EPA approved Subtitle D plans, including: Idaho,
Missouri, Montana, New Mexico, Utah, Maryland, Nevada, and West Virginia. Seven of these states contain
one or more facilities that generate special wastes addressed by this report.
The definition of solid waste in the federal solid waste regulations is intended to include wastes
generated by the mineral processing industry. According to the federal statute, all wastes must be disposed in
compliance with EPAs criteria listed in 40 CFR Part 257.
Waste disposal facilities that meet the criteria in 40 CFR 257.2 are defined as sanitary landfills.
Facilities that do not comply with the regulations are defined as open dumps. Open dumping is prohibited
under Section 4005 of RCRA. A disposal site such as a tailings pond or waste pile at a mining or processing
facility is treated as a "sanitary landfill" or an "open dump." If a site is found to meet EPAs criteria, it could
be considered a sanitary landfill and allowed to continue operating. If a disposal site does not meet EPA's
criteria, the site could be treated as an "open dump" and must be closed or upgraded in accordance with a
compliance schedule outlined by the state.
-------
Appendix D-1: Existing Federal Regulatory Controls D-1 -5
5. Water Quality
The Clean Water Act
The primary statute for controlling water pollution from mineral processing facilities is the Federal
\Vfrter Pollution Control Act of 1972. amended in 1977 as the Clean Vfcter Act (CWA). The law establishes
the national goals of eliminating the discharge of pollutants into navigable waters and, "water quality which
provides for the protection and propagation of fish, shellfish, and wildlife and provides for recreation in and
on the water."
Under the Clean Wbter Act, "the discharge of any pollutant by any person" from a point source into
the surface waters of the nation, except as authorized by a permit, is illegal [Section 301(a)]. Accordingly, any
entity seeking to discharge a wastewater effluent to a surface water body must apply for a permit. Permits,
which can have terms of up to 5 years, are issued by EPA under the National Pollutant Discharge Elimination
System (NPDES) permit program. Title IV of the law establishes permit requirements. Generally, a permit
will set forth the specific "effluent limitations" that pertain to specific types of discharges. Permits also usually
contain compliance dates and any germane monitoring and reporting requirements.
EPA has approved state programs for implementing the NPDES requirements for all of the states
analyzed in this report except for: Arizona, Idaho, New Mexico, Texas, and Louisiana.
Under the law, EPA also has the responsibility for setting "effluent limitations," based on the
performance capability of treatment technologies. These "technology based limitations" ~ expressed in terms
of a pollutant concentration, and not the technology itself - must be established for various classes of
industrial discharges, which include a number of mineral processing categories. These limitations are the basis
for minimum requirements of NPDES permits. Permits for mineral processing facilities may require compli-
ance with effluent guidelines based on best practicable control technology currently available (BPT) or best
available technology economically achievable (BAT). Pursuant to Section 301(b) of the Act, dischargers were
required to achieve effluent limitations based on BPT or any more stringent limitation, including those
necessary to meet water quality standards, treatment standards, or schedules of compliance, established by state
or federal law, by July 1,1977. Facilities must have achieved effluent limitations based on BAT no later than
3 years after they were established or no later than March 31,1989.
Exhibit D-1-2 provides relevant citations for applicable effluent guidelines for the twelve commodity
sectors discussed in this report
The CWA also allows EPA to delegate Title IV authority for issuing NPDES permits to qualified
states. In such instances, only one state permit need be issued. In states where delegation has not occurred,
a federal permit must be obtained. In cases where the state does not have an approved NPDES program, such
as Texas, Louisiana, and Idaho, EPA applies the guidelines discussed above. EPA will also adopt any limits
necessary to achieve applicable state water quality standards.
The CWA also requires that states establish water quality standards for all surface waters. The
standards are subject to EPA approval, and must meet minimum federal criteria. However, states are allowed
to set more stringent requirements than those established by EPA. The law allows both EPA and the states
to impose "any more stringent [effluent] limitation, including those necessary to meet water quality standards"
[Section 301(b)(l)(C)]. The stringency of a particular set of water quality standards, established for stretches
or "reaches" of a water course, can significantly affect what will be required to comply with a discharge permit.
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D-1 -6 Appendix 0-1: Existing Federal Regulatory Controls
Exhibit D-1-2
Federal Regulations Establishing Applicable Effluent Guidelines
Commodity Sector
Alumina
Sodium Dichromate
CoaJ Gasification
Primary Copper
Elemental Phosphorus
Ferrous Metals
Hydrofluoric Acid
Primary Lead
Magnesium
Phosphoric Acid
Titanium TetrachJoride
Primary Zinc
Regulation
Existing Sources
40 CFR 421
40CFR415
None
40 CFR 421
None
40 CFR 420
40 CFR 415
40 CFR 421
40 CFR 436
40 CFR 41 8, 422
40 CFR 415
40 CFR 421
New Sources
40 CFR 421
40 CFR 41 5
None
40 CFR 421
None
40 CFR 420
40 CFR 415
40 CFR 421
None
40 CFR 41 8, 422
40 CFR 415
40 CFR 421
If primary processing facilities discharge to publicly-owned treatment works (POTWs), they are subject
to pretreatment standards for new and existing sources. Pretreatment standards for new sources from bauxite
(alumina), copper, lead, and zinc primary processing facilities are presented in 40 CFR Part 421. Pretreatment
standards for existing sources for lead and zinc are also included in 40 CFR Part 421; standards for existing
sources for bauxite (alumina) and copper have not been promulgated.
Nonpoint sources of pollution are addressed under the law's Section 208 areawide waste treatment
management planning program requirements, which require states to prepare detailed plans for waste
management and identification and mitigation of adverse environmental impacts of waste management
practices. Nonpoint sources are also specifically addressed by Section 319 of the Clean Vfeter Act
Amendments of 1987. Section 319 required states to submit to EPA a program for controlling nonpoint
pollution within 18 months of enactment of the amendments. The Act states that in each fiscal year, priority
may be given for receipt of federal grant monies to states which have included ground-water protection
activities as part of their nonpoint pollution control programs.
Other provisions of the CWA which may affect mineral processing sites are requirements for the
disposition of dredged fill materials and waste sludges under Section 404 and controls on the release of oil
or hazardous substances under Section 311.
The Safe Drinking Water Act
The Safe Drinking ^frter Act (SDWA), has several provisions that are significant to mineral
processing facilities, including the law's requirements for setting drinking water regulations and Maximum
Contaminant Levels (MCLs) for toxic water contaminants, and for regulating underground injection of wastes
and protecting sole source aquifers. MCLs are "the maximum permissible level of a contaminant in water
-------
Appendix D-1: Existing Federal Regulatory Controls D-1 -7
which is delivered to any user of a public water system" (Section 1401). EPA is responsible for establishing
MCLs for pollutants in drinking water. MCLs for many of the inorganic compounds found at mining waste
sites are set forth in 40 CFR 141.11(b). The MCLs for the waste streams analyzed in this report are:
Contaminant
Chromium
Lead
Level in mg/L
0.05
0.05
The MCLs constitute one of the primary classes of applicable and relevant or appropriate
requirements (ARARs) that can be used to determine the level of cleanup required at Superfund sites
containing mining wastes (see CERCLA Section 122(d)(2)(A)). The SDWA also requires the Agency to
establish secondary MCLs; that is, standards that reflect welfare factors such as odor, taste, and color. While
these may have little or no direct effect on human health, their violation can be used to justify the
abandonment of a water source, or treatment to remedy the problem. For the wastes analyzed in this report,
the secondary drinking water standards are:
Contaminant
Copper
Zinc
Iron
Surfate
Level in mg/L
1
5
0.3
250
Ground water is protected under Pan C of the SDWA, "Protection of Underground Sources of
Drinking Water," which sets forth requirements for regulating waste disposal through the use of underground
injection techniques. Generally, the provision sets criteria for protecting the quality of aquifers used for
drinking water from potential contamination from such techniques. EPA regulations pertaining to these
provisions of the law can be found at 40 CFR Parts 144-147.
These statutory provisions focus on the use of Underground Injection Control (UIC) techniques,
which entail injection of fluids for waste disposal or resource recovery. Well injection is the subsurface
emplacement of fluids into any bored, drilled, or driven shaft or dug hole, whose depth is greater than the
largest surface dimension (40 CFR 146.03). Five classes of underground injection wells are designated in 40
CFR 144.6:
• Class I - used to inject hazardous waste beneath the lowermost formation con-
taining, within one-quarter mile of the well bore, an underground source of
drinking water (USDW);
• Class II - used to inject fluids which are brought to the surface in connection
with oil or natural gas recovery or storage operations;
e Class III - used to inject fluids for extraction of minerals, including mining of
sulfur by the Frasch process, in situ production of uranium or other metals, or
solution mining of salts or potash (includes only solution mining from ore
bodies that have not been conventionally mined; solution mining of conven-
tional mines such as slopes leaching is included in Class V);
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D-1 -8 Appendix D-1: Existing Federal Regulatory Controls
• Class IV - used to inject hazardous or radioactive waste into or above a
formation which within one-quarter mile of the well contains a USDW or into
or above a formation which has been exempted pursuant to 40 CFR 146.04
(and therefore is unlikely to ever be used as a drinking water source); and
• Class V - wells not included in the above four classes.
All of these classes of wells must be authorized by permit or rule and no injection may be authorized
if it results in movement of fluid containing any contaminant into a USDW (40 CFR Part 146). Existing Class
IV wells that inject into a USDW have been phased out and new ones are prohibited (40 CFR 144.13).
Another significant provision of the SDWA's ground-water protection authorities is found in Section
1424, which establishes the process for designating "sole source aquifers." Areas in which an aquifer "is the
sole or principal drinking water source for the area and which, if contaminated, would create a significant
hazard to public health" may be designated a sole source aquifer area. Pursuant to the requirements of this
provision, once an aquifer is established as a sole source aquifer, the federal government may not make any
kind of financial assistance available for any project in the protection area of the aquifer, with the exception
of monies that would be used to "plan or design the project to assure that it will not so contaminate the
aquifer." Section 1427 of the Act also provides for a "Sole Source Aquifer Demonstration Program," under
which states receive financial assistance for establishing sole source aquifer protection areas, and for
developing plans to protect such areas. Regulations concerning one such program under this provision can
be found at 40 CFR 149.
Provisions for wellhead protection were also adopted as part of the SDWA reauthorization. This
legislation established a nation-wide program to encourage states to develop systematic and comprehensive
programs within their jurisdictions to protect public water supply wells and wellfields from contamination.
1b date, twenty-nine states have submitted Wellhead Protection programs for review. Nine states have enacted
enabling legislation.
6. Air Quality
The primary statute for preventing and controlling air pollution from mineral processing sites is the
Clean Air Act of 1970. as amended in 1977 (42 USC §§ 7401-7626). The major goal of the Clean Air Act is
to protect and enhance the quality of the nation's air resources so as to promote the public health and welfare
and the productive capacity of its population.
In order to achieve its goals, the Clean Air Act establishes a framework to foster programs to prevent
and control air pollution, provide technical and financial assistance to state and local governments in
connection with the development and execution of air pollution prevention and control programs, and
encourage and assist the development and operation of regional air pollution control programs.
Under the authority of the Clean Air Act, EPA has established primary and secondary national
ambient air quality standards (NAAQS). Primary standards are intended to protect public health; secondary
standards are intended to protect public welfare. NAAQS are established for particulates, sulfur oxides,
carbon monoxide, ozone, nitrogen dioxide, and lead. Particulates and sulfur oxides are of special concern to
the mineral processing industry.
States are required to prepare State Implementation Plans (SIPs) detailing a strategy for meeting
primary NAAQS. SIPs will include emission limits for existing sources necessary to maintain or bring the area
into attainment with the NAAQS. The SIPs must also include provisions for implementing the Prevention
and Significant Deterioration (PSD) program for attainment and unclassifiable areas, and visibility protection
for certain pristine areas. Once EPA approves and SIP, it becomes federally enforeable.
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Appendix D-1: Existing Federal Regulatory Controls D-1 -9
On July 1, 1987, EPA issued revisions to the national ambient air quality standards (NAAQS) for
paniculate matter (52 FR 24634). The revisions included the following four key changes:
• Replaced total suspended particulates (TSP) as the indicator for paniculate
matter for the ambient standards with a new indicator that includes only those
panicles with a nominal aerodynamic diameter less than or equal to 10
micrometers (PM10);
• Replaced the 24-hour primary TSP standard of 260 /j-g/m3 with a 24-hour PM10
standard of 150 /xg/m3 with no more than one expected exceedance per year;
• Replaced the annual primary TSP standard of 75 /ig/m3 with a PM10 standard
of 50 /xg/m3, expected annual arithmetic mean; and
• Replaced the secondary TSP standard of 150 /xg/m3 with 24-hour and annual
PM10 standards that are identical in all respects to the primary standards.
EPA recognizes the potentially large contribution of fugitive dust to total paniculate matter in an area
and created a fugitive dust policy in 1977 applicable to nonattainment areas for TSP. In this policy, EPA
concluded that fugitive dust caused greater environmental impact in urban areas than in rural areas. EPA's
lesser concern over TSP in rural areas is based on the following four factors: (1) the paniculate matter
consists of native soil which was believed to pose less of a health hazard than particles found in urban areas,
(2) the population affected was small, (3) the economic base to support control was small, and (4) the cost
of controlling miles of unpaved roads and acres of open land could be unreasonable. EPAs 1977 policy was
that urban areas should receive the highest priority for development of programs for control of fugitive dust
and programs in rural areas should focus on control of large existing manmade fugitive dust sources such as
tailings piles and mining operations. In a notice on July 1, 1987 (52 FR 24716), EPA requested comments
on three alternatives to the existing fugitive dust policy under consideration in response to the revised
NAAQS. Until a revised policy is issued, EPA will continue to operate under the existing fugitive dust policy.
Any source with the potential to emit 250 tons per year or more of any air pollutant is considered
a major emitting facility and is subject to the PSD program. Generally, one year of baseline air quality
monitoring data is required before a PSD permit application is submitted. The application must demonstrate
that emissions from the facility or modifications to a facility will not exceed the applicable increments or the
NAAQS. The applicable increments are allowable increases in concentration of pollutants over a baseline
concentration, but not to exceed the NAAQS.
Major stationary sources are required to apply the best available control technology (BACT) to
pollutants that will be emitted in significant amounts [40 CFR 52.21(j)]. BACT may not be less stringent than
new source performance standards (40 CFR Part 60) or National Emission Standards for Hazardous Air
Pollutants (NESHAPs)(40 CFR Part 61). Specific emissions standards are set forth under NESHAPs for
inorganic arsenic emissions from primary copper smelters (50 /ig/dscm) and for radionuclide emissions from
elemental phosphorus plants. The NESHAP controlling radionuclides from elemental phosphorus plants only
addresses stack emissions, not slag or other potential radionuclide sources.
New source performance standards (NSPS) are emission limits that have been set by EPA to apply
to new or modified sources which may contribute significantly to air pollution. NSPS requirements apply to
individual operations within a facility. NSPS are not permit requirements, but they do require that
performance tests be conducted (40 CFR 60.7-60.8).
-------
D-1 -10 Appendix 0-1: Existing Federal Regulatory Controls
7. Wetlands Protection
Section 404 of the Clean Water Act authorizes the Secretary of the Army, acting through the Chief
of Engineers, to issue permits, after notice and opportunity for public hearing, for the discharge of dredged
or fill material into the waters of the United States at specified disposal sites. The phrase "waters of the
United States" has broad meaning and is defined in 33 CFR 328.3 as follows:
• All waters used or that may be used "...in interstate and foreign commerce;"
• "All interstate waters and their tributaries, including interstate wetlands;"
• "All other waters such as intrastate lakes, rivers, streams including intermittent
streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows,
playa lakes, or natural ponds, the use, degradation or destruction of which
could affect interstate or foreign commerce..." including any such waters used
for recreational purposes, fishing, or industrial purposes by industries in
interstate commerce;" and
• "All impoundments of waters otherwise defined as waters of the United States,"
including tributaries of waters defined above, the territorial seas, and wetlands
adjacent to waters defined above.
Certain discharges of dredged and fill material into waters of the United States are permitted under
the "nationwide permit" system as defined in 33 CFR 330. Nationwide permits are designed to allow certain
activities to occur with little, if any, delay or paperwork and are valid only if the conditions applicable to the
nationwide permits are met. Authorized activities are typically those which have minimal direct or cumulative
environmental impacts (33 CFR 323.2(h)). Specific authorized activities are identified in 33 CFR 330.5 and
include, among others, seismic survey activity, structures for the exploration, production, and transportation
of oil, gas, and minerals on the outer continental shelf within leased areas; and bank stabilization activities.
According to 33 CFR 323.3, individual 404 permits are required for any discharges to waters of the United
States not covered by (1) the nationwide permit program, or (2) for discharges not requiring permits, such as
those which might occur as a result of fanning, silviculture, and ranching (33 CFR 323.4(a)). Mineral
processing activities that involve discharges of dredged or fill material to waters of the United States may
require individual 404 permits from the Corps if: (1) the activity is not covered by a nationwide permit and
(2) the activity is not exempt from regulation.
The Corps of Engineers must review applications for Section 404 permits in accordance with
guidelines promulgated by the EPA Administrator under authority of Section 404(b)(l) of the Clean Water
Act. The Section 404(b)(l) guidelines specify that "no discharge of dredged or fill material shall be permitted
which will cause or contribute to significant degradation of the waters of the United States" (40 CFR
230.10(c)).
8. Other Applicable Federal Laws
The laws discussed below are not all directly relevant to the mineral processing industry, but may be
important for certain operations or in the overall consideration of environmental impacts.
The National Environmental Policy Act
Enacted in 1969, the National Environmental Policy Act (NEPA), 42 USC 4341, requires that,
to the fullest extent possible, the policies, regulations, and public laws of the
United States shall be interpreted and administered in accordance with the
policies set forth in this Act, and (2) all agencies of the Federal Government
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Appendix D-1: Existing Federal Regulatory Controls D-1 -11
shall include in every recommendation or report on...major Federal actions
significantly affecting the quality of the human environment, a detailed state-
ment...on (i) the environmental impact of the proposed action....
This requirement for preparation of an Environmental Impact Statement (EIS) establishes the
framework and process by which EPA and the Council on Environmental Quality (CEQ) may impose the
environmental protection requirements contained in all other federal environmental regulatory statutes on a
wide variety of projects and activities. Environmental assessments must be prepared for any ore processing
activities on federal lands, and similar activities that involve the use of facilities constructed with federal funds.
EISs may be required for actions with significant impacts. CEQ regulations pertaining to the implementation
of this law are found at 40 CFR Parts 1500-1508. EPA's corresponding regulations are found at 40 CFR 6.
These requirements apply to Stauffer Chemical Company's elemental phosphorus facility in Silver Bow,
Montana, Cyprus Mining Corporation's copper smelter in Claypool, Arizona, and Magma's copper smelter in
San Manuel, Arizona, which are all located in National forests and Chevron Chemical Company's phosphoric
acid plant in Rock Springs, Wyoming, which is on land owned by Bureau of Land Management, U.S.
Department of Interior.
The Federal Land Policy and Management Act
The Federal Land Policy and Management Act of 1976 (FLPMA, 43 USC 1732, 1733, and 1782)
authorizes the Bureau of Land Management (BLM) to regulate mining activities on its lands with respect to
the environmental effects of such activities. Four of the facilities analyzed in this report are on lands owned
by the federal government. The Bureau's regulations implementing this law (43 CFR 3809) are intended to
prevent unnecessary or undue degradation of its lands, or lands that are under consideration for inclusion in
the national wilderness system.
The regulations provide for reclamation of lands disturbed by mining and define three levels of mining
operations. The first level, "casual use," applies to areas where mechanized earthmoving equipment and
explosives are not used; a second level applies to surface disturbances of less than five acres per year; and a
third level applies to disturbances of over five acres per year. For operations in the second level, operators
must submit a letter or notice of intent; for operations on the third level, operators must submit a plan of
operation that describes the proposed operation, including reclamation plans. Bonds are required when an
operator has a record of noncompliance. These regulations apply to Chevron Chemical Company's phosphoric
acid facility located in Rock Springs, Wyoming, which is situated on lands owned by BLM.
Forest Service Requirements
The Forest Service, U.S. Department of Agriculture, maintains regulations governing the use of the
surface of National Forest System lands in connection with operations authorized by the United States mining
laws. The regulations (36 CFR 228 Subpart A) are intended to "minimize adverse environmental impacts on
National Forest system surface resources."
The regulations require that a "notice of intent to operate" be submitted by operators proposing to
conduct prospecting or mining activities on Forest Service lands if the proposed activities might cause
disturbance of surface resources. A proposed plan of operations is required if, in the judgment of the
authorized Forest Service officer, operations would cause significant surface disturbance (e.g., if mechanized
earthmoving equipment or explosives are to be used). All operations must minimize adverse environmental
impacts to the extent feasible and must take into consideration federal, state, and local requirements
concerning solid waste disposal and air and water quality. Consideration must also be given to the reclamation
of disturbed lands. Reclamation bonds may be required by the authorized officer. These regulations also
apply to the Stauffer Chemical Company plant in Silver Bow, Montana, and the Cyprus Mining Corporation's
smelter in Claypool, Arizona, and Magma's copper smelter in San Manuel, Arizona.
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Appendix D-2
Existing Regulatory Controls
Addressing Mineral Processing Wastes
in Selected States
-------
Appendix D-2
Existing Regulatory Controls Addressing
Mineral Processing Wastes in Selected States
EPA's goal in the analysis of state regulatory programs was to determine the current state regulatory
status of the mineral processing wastes generated by the twelve commodity sectors addressed in the Report
to Congress. The "State Regulation" section of each chapter (X.4.2) summarizes the findings of this analysis.
This appendix presents the more detailed information upon which EPA based its review of and conclusions
regarding state waste regulatory programs.
The analysis of state regulatory programs consisted of three steps. The first step focused on reviewing
material in a report on state-level regulation of mining and mineral processing wastes ("COM report").1 The
second step was to perform a more detailed review of individual state statutes and regulations. This step
included the selection of a subset of states for further study. The final step in the analysis involved contacting
state officials in the eighteen study states to clarify state regulations and obtain facility-specific information
where possible. The three steps of the state regulatory analysis are summarized below.
First, EPA examined the material in the CDM report that pertains to all 29 states with one or more
facilities considered in the Report to Congress, and summarized portions of the hazardous waste, solid waste,
air quality, and water quality statutes and regulations that are relevant to the current disposition of the special
study wastes. Although the CDM report provides a general overview of state statutory and regulatory
requirements addressing wastes from the extraction, beneficiation, and processing of ores and minerals in all
50 states, it was not designed to provide the detailed analysis of the scope, and in particular, the
implementation of regulations that address mineral processing wastes, that EPA believes is necessary for the
Report to Congress.
The second step of EPA's analysis, therefore, was designed to provide more detailed information on
the scope and implementation of mineral processing wastes. Time and resource constraints made it impossible
to perform a detailed regulatory analysis on all of the states that contain facilities that generate a special
mineral processing waste. Consequently, this step in the analysis involved selecting a representative sample
of the 29 states for further analysis, in order to balance the need for comprehensive coverage of the mineral
commodity sectors with the need to work with a manageable number of states.
To select a subset of states, EPA employed the following criteria: (1) the percentage of facilities in
each state and in each sector covered by the regulatory analysis; and (2) the percentage of total waste volume
generated by each waste stream and sector covered by the regulatory analysis. Exhibit D-2-1 of this appendix
demonstrates the high percentage of facilities and total waste volume represented by the eighteen states chosen
for further study, while Exhibit D-2-2 illustrates the location of these 19 study states.
Although this second step resulted in a detailed analysis of the statutes, regulations, and other
information for each of the eighteen selected states, EPA found that the scope of state programs was not
always made clear by the states' statutory and regulatory language. The final step of the analysis, therefore,
consisted of calling state officials in order to learn how those statutes and regulations are interpreted in
practice, and to obtain facility-specific implementation information where possible. The information compiled
from these contacts was combined with the existing information on statutory and regulatory requirements to
produce a final implementation analysis, which reviews the existing regulatory structure applicable to the 20
mineral processing wastes generated by the twelve commodity sectors considered in this Report to Congress.
1 Camp, Dresser, and McKcc Federal Programs Corporation (CDM). State Regulation of Solid Wastes from the Extraction.
Beneficiation. and Processing of Non-Fuel Ores and Minerals. June 2,1989. Prepared for U.S. Environmental Protection Agency, Office
of Solid Waste; Document Control Number T1142-ROO-DR-DELC-1.
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D-2-2 Appendix D-2: Existing Regulatory Controls
Exhibit D-2-1
Summary of Results of Selection Criteria Evaluation
Sector
Alumina
Chromate
Coal Gasification
Copper
Elemental Phosphorus
Ferrous Metals
Hydrofluoric Acid
Lead
Magnesium
Phosphoric Acid
Titanium
Zinc
Total
Number of
Facilities
5
2
1
10
5
28
3
5
1
21
9
1
Number of
Facilities in
Study State*
4
2
1
9
5
19
3
4
1
20
S
1
Percent of
Facilities In
Study States
80
100
100
90
100
68
too
80
100
95
56
100
Percent Waste
Volume Generated
In Study States
93
NA""
100
90
NA
2 of 2 facilities CBI
3 of 10 facilities CBI
3 of 5 facilities CBI
2 of 28 facilities CBI
1 facility NR1"
3 of 5 facilities CBI
2 of 21 facilities CBI
8 of 9 facilities CBI
(a) CBI = Confidential Business Information
(b) MA = Insufficient data to calculate accurately due to Confidential Business Information (CBI) status
(c) A single hydrofluoric acid facility owned by duPorrt did not submit a survey response
The complete findings of this analysis have been included on a state-by-state basis in the remainder
of this appendix.
Arizona
There are three copper processing facilities in Arizona under study for this report. The facilities, their
locations, and the waste streams they generate are presented in Exhibit D-2-3. All three generate furnace slag,
while only the facility in Hayden generates calcium sulfate sludge, and only the facility in San Manuel
generates slag tailings.
Arizona adopts the Federal exemption from hazardous waste regulation for wastes from the extraction,
beneficiation, and processing of ores and minerals. Arizona's Solid Waste Management Law and Solid \Vfrste
Rules include coverage for industrial wastes. According to State officials, however, the State's emphasis in
implementing its regulations has been on municipal solid waste, especially with regard to the siting and
construction of solid waste landfills. The State has not imposed regulations specifically regulating wastes from
mining and mineral processing operations.
The implementation of Arizona's water quality control statutes and regulations affects mineral
processing wastes more directly. As part of the State's initial ground-water protection efforts, all existing
dischargers were required to submit notices of disposal. The State established priorities through the evaluation
of these notices and proceeded to address them in order through its new Aquifer Protection Program.
According to State officials, they are behind schedule in permitting the numerous facilities. Permit
requirements are based on the Best Available Demonstrated Control Technology (BADCT). Permit
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Exhibit D-2-2
Distribution of States Selected For Further Statutory and Regulatory Analysis
for the Mineral Processing Wastes Report to Congress
O
States In Which One or More RTC
Mineral Processing Facilities are Located-
Not Selected for Further Study
(11 States)
States In Which One or More RTC Mineral
Processing Facilities are Located-Selected for Further
Statutory and Regulatory Analysis (18 States)
* The number In each state Indicates the number of RTC mineral processing facilities located In the state.
•o
•o
n
o.
X
o
O
IO
00
I
S
o
^
O
o
o
(A
O
ro
CJ
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0-2-4 Appendix D-2: Existing Regulatory Controls
Exhibit D-2-3
Mineral Processing Facilities Located in Arizona
and the Waste Streams They Generate
Facility
ASARCO
Cyprus
Magma
Location
Hayden
Claypool
San Manuel
Sector
Copper
Copper
Copper
Waste Streams
1. Slag
2. Calcium Surfate Sludge
1. Slag
1. Slag
2. Slag Tailings
requirements include liners and prescribed procedures for liner installation, consideration of treatment before
discharge or disposal, and monitoring of all kinds, including ground-water monitoring and double liner leak
detection. Surface impoundments, including holding impoundments, storage settling impoundments, treatment
or disposal pits, ponds, lagoons, and mine tailings piles or ponds are specifically listed as discharging facilities
that must be permitted. The State has inspection and enforcement authority through the Aquifer Protection
Program and has utilized both of those authorities in the past.
The Arizona Rules and Regulations for Air Pollution Control adopt Federal new source and existing
source performance standards for primary copper smelting operations. In addition, the regulations include
fugitive dust limitation conditions for tailings piles and ponds.
The Hayden facility does not have an aquifer protection permit. The facility in Claypool received an
aquifer protection permit in October 1989 for a tailings reprocessing unit; however, other operations at the
facility, including hydraulic renaming of old waste piles, are not currently subject to permit requirements. The
facility in San Manuel has an aquifer protection permit for its heap leaching operation, but not for its tailings
pond. According to State officials, the lack of permits at these facilities is attributed to the emphasis put on
permitting new facilities, and to the long list of existing facilities that need to be permitted.
Delaware
There is only one mineral processing facility in Delaware that is under study for this report. The
single facility is a titanium tetrachloride processing facility that generates chloride process waste solids. That
facility, its location, and the waste stream it generates are presented in Exhibit D-2-4.
Exhibit D-2-4
Mineral Processing Facilities Located in Delaware
and the Waste Streams They Generate
Facility
duPont
Location
Edgemoor
Sector
Titanium
Tetrachloride
Waste Streams
1 . Chloride Process Waste Solids
-------
Appendix 0-2: Existing Regulatory Controls D-2-5
The Delaware Hazardous Waste Management Regulations specifically exclude wastes from the
extraction, beneficiation, and processing of ores and minerals from regulation as hazardous waste. Therefore,
chloride process waste solids from titanium dioxide production are not regulated as hazardous waste in
Delaware.
The Solid Waste Disposal Regulations include in their definition of industrial waste, any substance
resulting from the operation of or from any process of industry, manufacturing, trade, or business, or from the
development of any natural resource. The regulations list specific design standards for on-site industrial
landfills that include: analysis of the chemical and physical properties of the industrial waste; plans for
leachate collection, treatment, and disposal systems; hydrological reports, including test borings to determine
the soil and ground-water conditions; methods for venting and monitoring gases within the landfill; liners; and
setback areas. Sanitary landfills have separate design and operating standards, most of which mirror those that
apply to industrial landfills. One difference is the use of a toricity test that must be applied to any non-
municipal waste that is to be disposed in a municipal landfill. Industrial landfill permits specify which wastes
can be accepted. Sanitary landfills, in contrast, tend to receive many different types of wastes; the toxicity test
serves as a means of preventing hazardous wastes from being disposed of in these landfills. A new set of solid
waste regulations was enacted in December 1989, and all the existing industrial landfills are in the process of
coming under these requirements.
At present, all solid waste disposal facilities are required to submit either annual or quarterly reports
assessing their compliance with their landfill permits. They also are required to submit closure plans that must
include provisions for landfill capping, gas control, surface water run-off control, ground-water monitoring,
and 30-year post-closure care. Although the State can and does conduct on-site inspections, it can only revoke
a permit and deliver a cease action order. It cannot force remediation activities on the part of the facility.
Inactive or abandoned sites are sometimes passed over to the solid waste division from the State
Superfund division. There are no official regulations concerning how the solid waste division must deal with
these sites. The State is presently working under the authority of a policy paper that requires the present
owner of the property to totally remove all pollutants from the site. There have been some legal challenges
to this policy paper, but the State has been successful in the majority of the cases.
Delaware does have an approved NPDES program and continues to issue discharge permits for all
point source discharges in the State. Permits for industrial wastewater discharges must require treatment that
reflects, at a minimum, a practicable level of pollutant removal technology. Management practices required
in the permits include specifications for monitoring of effluent levels and operating practices for the permitted
facilities.
The titanium tetrachloride facility in Delaware under study for this report is the duPont facility in
Edgemoor, DE. It currently generates chloride process waste solids, which are treated and landfilled. There
is a surface impoundment on-site where the solids are co-managed with other wastes from the process.
Initially, the facility had a solid waste permit for the on-site surface impoundment and for the process of
allowing the chloride process waste solids to settle out to be eventually dredged and landfilled at another
location. This landfill is on Cherry Island and is permitted separately as an industrial landfill. It is not clear
from speaking with State officials whether the Cherry Island landfill is situated on land that is owned by the
duPont company. The solid waste permit for the on-site impoundment was transferred to the Delaware \toter
Resources Division in early 1990, as were all surface impoundment permits currently in existence in the State.
The Water Resources Division of the Delaware Department of Natural Resources and Environmental
Conservation has yet to address the existing permit situation and has instructed duPont to continue operating
under the terms of the solid waste permit until further notice. duPont also obtained a NPDES permit, which
expires in September 1994, to discharge from the on-site surface impoundment. Requirements of the permit,
in addition to the regimen of effluent monitoring from the four outfalls, include bio-monitoring procedures.
-------
D-2-6 Appendix D-2: Existing Regulatory Controls
Florida
As shown in Exhibit D-2-5, there are 12 phosohoric acid facilities in Florida that are under study for
this report. All 12 facilities produce both phosphogypsum and process wastewater.
Exhibit D-2-5
Mineral Processing Facilities Located in Florida
and the Waste Streams They Generate
Facility
Agrico
Central Phosphate
CF Chemicals
Conserv, Inc.
Farmland Ind.
Qardinier, Inc.
IMC Fertilizer
Royster
Royster
Seminole Fertilizer
US Agri-Chem
Occidental Chemical
Location
Mulberry
Plant City
Bartow
Nichols
Bartow
Riverview
Mulberry
Mulberry
Palmetto
Bartow
Ft. Meads
White Spring*
Sector
Phosphoric Acid
Phosphoric Acid
Phosphoric Acid
Phosphoric Acid
Phosphoric Acid
Phosphoric Acid
Phosphoric Acid
Phosphoric Acid
Phosphoric Aoid
Phosphoric Acid
Phosphoric Add
Phosphoric Acid
Waste Streams
1 . Process Wastewater
2. Phosphogypsum
1 . Process Wastewater
2. Phosphogypsum
1 . Process Wastewater
2. Phoephogypsum
1 . Process Wastewater
2. Phosphogypsum
1. Process Wastewater
2. Phosphogypsum
1 . Process Wastewater
2. Phosphogypsum
1, . Process Wastewater
2. Phosphogypsum
1 . Process Wastewater
2. Phosphogypsum
1. Process Wastewater
2. Phosphogypsum
1 . Process Wastewater
2. Phosphogypsum
1 . Process Wastewater
2. Phosphogypsum
1 . Process Wastewater
2. Phosphogypsum
The Florida Hazardous Waste Rules exclude "discarded material generated by the mining and chemical
or thermal processing of phosphate rock and precipitates resulting from neutralization of phosphate chemical
plant process and nonprocess waters" from regulation as hazardous waste. The rules incorporate by reference
the Federal identification of hazardous waste, including the exemption for wastes from extraction,
beneficiation, and processing of ores and minerals.
The Florida Solid Vfaste Disposal Facilities Regulations do not contain specific requirements
pertaining to phosphogypsum stacks, though the State is currently drafting regulations to address them. The
solid waste rules prohibit disposal except by sanitary landfill, incineration, recycling process, or "other approved
method" consistent with the requirements of the rules. In the absence of express guidelines for stacks, the
State has adopted modified landfill requirements, when appropriate, for regulation of phosphogypsum stacks.
After considering ground-water monitoring data from facilities without liners under the stacks and from one
-------
Appendix D-2: Existing Regulatory Controls D-2-7
facility with a stack liner, the Department of Environmental Regulation required liners for all new stacks and
expansions of old stacks.
According to State officials, phosphoric acid facilities may have two types of permits for their solid
waste disposal activities. Typically, old stacks have an Industrial Wastewater Discharge Permit. Under the
1988 Solid Waste Management Act, new facilities are required to obtain a solid waste disposal permit. Some
facilities may have both. Specific requirements for each facility are contained in the solid waste permit. The
rules delineate site restrictions for solid waste disposal facilities (e.g., no disposal in an area subject to frequent
and periodic flooding). Requirements in solid waste disposal permits may address location, performance
standards (e.g., liner requirements), and operations (e.g., ground-water monitoring). Florida is currently in
the process of developing operating and construction standards for stacks. There are no closure requirements
for any of the units.
Currently, the existing cooling ponds for wastewater are not required to be lined. According to State
officials, this will be addressed in the new regulations.
State officials have indicated that the Department has authority for on-site inspections and
enforcement authority to issue administrative and consent orders. They do not, however, have authority to
fine facilities for non-compliance. The Department must bring a facility operator to court to sue for damages.
The mechanism for ground water cleanup is a CAPRAP or "contamination assessment report and remedial
action plan."
Florida does not have an EPA-approved NPDES program. The Florida Wastewater Facilities
Regulations incorporate by reference Federal "Effluent Guidelines and Standards for Mineral Mining and
Processing" (40 CFR 436). The regulations contain standards (Title 17-6.310) that are more stringent than
the Federal Guidelines. According to the State official, however, these regulations apply to mining of
phosphate ore and not to processing. The cooling ponds associated with the phosphogypsum stacks are
required to adhere to the design and operating standards for earthen dams in Title 17-9.
Because of ongoing modification to the solid waste regulations with regard to design and operating
standards specific to phosphogypsum stacks and cooling ponds, the State official noted that the interim policy
is to require any new or expansion of existing stacks or ponds to be lined and undergo formal closure. Under
this policy, closure requirements include adequate cover to prevent infiltration, and run-off controls. The State
may require remedial action by the owner/operator, which could be in the form of slurry walls or a ground-
water recovery system.
According to the State official, all the ponds have run-on/run-off controls. The State has adopted the
Federal Guidelines, which require controls to manage the storm water from a 25 year, 24 hour storm.
Ground-water monitoring around the stacks also is required. According to the State official, the new stacks
and ponds rarely need to discharge because of their huge capacity. All the phosphogypsum stacks and ponds,
however, do have Federal NPDES permits in case there is a need to discharge to surface waters.
The State official related that the typical facility is comprised of a mine and an associated chemical
plant. The mine will have its own Industrial Waste Permit, and the chemical plant also will have an Industrial
Waste Permit. Therefore, a facility typically has 2 permits for disposal, each addressing its own discharge. An
entire facility, however, typically only has one NPDES permit.
Under the Florida Air Pollution Rules, emissions from the phosphate industry are regulated. Rules
exist for wet phosphoric acid production. According to a State official, phosphogypsum stacks and cooling
ponds are not expressly mentioned in air permits. The basic concerns from these systems are fugitive dust and
radon emissions. According to the State official, the stacks tend to "heal over," or crust Fugitive dust and
radon, therefore, have not historically been a concern for the air program. The State official related that the
stacks are part of a wet system, which also helps to control potential dust emissions. Nonetheless, the
operator of the Gardinier facility covered its old phosphogypsum stack with grass at closure in order to control
future paniculate emissions. This was, however, in response to a local rather than a State requirement
-------
D-2-8 Appendix 0-2: Existing Regulatory Controls
Idaho
There are two nhosphoric acid facilities and two elemental phosphorus facilities in Idaho that are
under study for this report. The facilities, their locations and the waste streams they generate are presented
in Exhibit D-2-6.
Exhibit D-2-6
Mineral Processing Facilities Located in Idaho
and the Waste Streams They Generate
Facility
Monsanto
PMC Corporation
J.R. SlmpJot
Nu-West Industries
Location
Soda Springs
Pocatello
Pocatello
Soda Springs
Sector
Elemental Phosphorus
Elemental Phosphorus
Phosphoric Acfd
Phosphoric Acid
Waste Streams
1. Slag
1. Slag
1 . Process Wastewater
2. Phosphogypsum
1 . Process Wastewater
2. Phosphogypsum
Under the Idaho Hazardous Waste Management Regulations, "solid waste from the extraction,
beneficiation, and processing of ores and minerals, including coal, phosphate rock, and overburden from the
mining or uranium ore" are exempt from regulation as hazardous waste.
According to State officials, phosphogypsum and process wastewater from phosphoric acid production
are subject to neither the Idaho Solid Waste Law, nor the Idaho Solid Waste Management Regulations. No
solid waste permits are required for disposal of mineral processing wastes. Idaho does ban the use of
elemental phosphorus slag as construction material in habitable structures.
Idaho does not have a Federally-approved NPDES program. The Idaho Water Quality Standards and
Wastewater Treatment Requirements regulate the State's waters based upon water use classifications. Non-
sewage discharges must be treated to the extent necessary to ensure compliance with Sections 301 and 304 of
the Federal Water Pollution Control Act.
Paniculate matter emission limitations applicable to any process are given in the Air Pollution
Control Regulations. According to State officials, the air permits do not contain specific requirements
regarding phosphogypsum stacks, cooling ponds, and slag piles. The Simplot and Nu-West facilities are
broadly responsible for "reasonable control of fugitives," but there is no express mention of stacks or ponds
in the air permit.
Indiana
Four facilities generate special wastes from mineral processing in Indiana. Each of these facilities is
a fully integrated ferrous facility generating iron and basic oxygen furnace steel slag and air pollution control
dust and sludge. Exhibit D-2-7 shows the names and locations of the four ferrous facilities in Indiana.
Ferrous wastes (iron and steel slag and iron and steel air pollution control dust and sludge) are the
only special wastes from the processing of ores and minerals generated in Indiana.
The Indiana Solid Waste Management Permit Regulations exempt from regulation:
(13) The legitimate use of iron and steelmaking slags including the use as a base for road
building, but not including land reclamation except as allowed under subdivision (15)...
-------
Appendix 0-2: Existing Regulatory Controls D-2-9
Exhibit D-2-7
Mineral Processing Facilities Located in Indiana
and the Waste Streams They Generate
Facility
Bethlehem Steel
Inland Steel
LTV Steel
US Steel
Location
Burns Harbor, IN
E. Chicago, IN
Indiana Harbor, IN
Gary, IN
Sector
Ferrous
Ferrous
Ferrous
Ferrous
Waste Stream*
t. Blast Furnace Slag
2. Blast Furnace APC Oust/Sludge
3. Basic Oxygen Slag
4. Basic Oxygen APC Oust/Sludge
1 . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Slag
4. Basic Oxygen APC Dust/Sludge
1. Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Slag
4. Basic Oxygen APC Oust/Sludge
1 . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Slag
4. Basic Oxygen APC Dust/Sludge
(15) Other uses of solid waste may be approved by the commissioner if the commissioner
determines them to be legitimate uses that do not pose a threat to public health and the
environment (329 1AC 2-3-1).
State officials noted that, although this means that iron and steel slag may not be subject to regulation in a
number of cases, this provision is interpreted cautiously and land reclamation or any use of slag would only
be allowed with proof that no contamination of the environment could result.
APC dust and sludge is considered a special waste by the State of Indiana and may be only disposed
off-site in one of twelve landfills designated to accept special waste, or in other landfills as determined on a
case-by-case basis. Requests for disposal of special waste are matched by the State with a landfill or disposal
site approved by the State. Generators generally indicate the landfills in which they would like approval to
dispose of special waste. The EP toxicity test and the neutral water leaching test are used to determine the
degree of hazard a waste may pose, and are part of an extensive application submitted to the State in order
to determine suitable sites for disposal. Sites previously approved for solid waste disposal will be reviewed
by the State under the authority of the proposed rule. Another provision of the proposed rule will require
the State to issue certifications of special waste status to industry. The certifications will provide generators
with a permit to dispose of waste at a landfill of their choice. Although the details of this provision are not
established, industry could have a greater opportunity to select the most competitively priced waste
management facility for disposal of special waste.
On-site disposal of APC dust and sludge, a practice used by both Inland and US Steel, was informally
exempt from these requirements until February 1989, when a new rule regulating residuals went into effect.
Although disposal of dust and sludge was informally monitored by State inspectors, facilities were not required
to meet the standards of special waste landfills.
The new rule gave facilities until September of 1989 to file a notification to the State including basic
information on the industrial process undertaken at the facility, what wastes were generated, including any
available waste characterization data, and how the waste was managed at that time. After reviewing this
material, State officials will conduct further waste characterization sampling and determine either 1) what types
of off-site landfills these wastes may be hauled to, or 2) what type of restricted waste landfill permit these
-------
D-2-10 Appendix D-2: Existing Regulatory Controls
facilities would have to apply for. Permits for these facilities will be called in on a schedule. By April 1990,
three of the four iron and steel facilities in Indiana.had filed the required notification.
Following determination of what type of site may accept the wastes as described in the facility
notifications, sites must either meet the new requirements or close. Restricted sites will range from sanitary
landfills, which must have ground-water monitoring wells, ten feet of clay barrier or a synthetic liner, and
extensive evaluation by State officials, to the least restrictive landfill that may not even be required to have
monitoring wells.
Existing sites that were required to close could, in the most stringent scenario, be required to be
covered with two feet of clay and six inches of topsoil and vegetation, grade to a minimum slope and meet
certain erosion control requirements through the placement of inert materials, in order to prevent pooling;
establish monitoring wells; and possibly undertake a post-closure period of ten years that would include
biannual ground-water monitoring, inspection and maintenance of cover, and financial assurance. Rule 9 of
the regulation includes requirements on determining the type of waste to be disposed of; Rule 10 includes
minimum design standards. State officials cautioned, however, that none of the waste management operations
at any of the facilities had been classified at this time, and it was not possible to estimate exactly what
requirements each facility would have to meet.
Waste management requirements under the new rule will be determined on a case-by-case basis, under
the assumption that each material is somewhat different. Although the State may take enforcement action
and exercise corrective action authority at any time when there is an imminent threat to human health and
the environment, State officials were not able to estimate when waste management requirements established
under the new rule would be established for each facility. Financial penalties of up to $25,000 a day per
violation are possible; the State is presently working on a penalty matrix.
In the case of inactive and abandoned sites, the State may require cover and leachate abatement
activities, depending upon a determination of the potential threat to human health and the environment.
Requirements for ground-water controls vary by facility and by facility NPDES permit. A substantial
amount of run-off from Bethlehem Steel may go to a lagoon system, although for the most part, slag piles are
unlikely to be required to have run-off controls, according to a State official. Bethlehem is apparently built
on a sandy base that prevents a substantial amount of run-off. The Inland and Armco facilities in Indiana,
however, are required to have run-off controls for their slag disposal or management sites through the
facilities' NPDES permits. Although most of the cooling water at US Steel is recirculated, some is blown-
down, and excess is discharged with rain run-off from the slag piles. State officials indicated that circulating
water at Inland dust and sludge impoundments is re-used and has been examined and demonstrated to pose
no threat of water contamination.
Although the four primary steel mills in Indiana are required to submit fugitive dust program plans
to the State, according to State officials, these plans have not been approved or disapproved. Steel mills must
in general employ fugitive dust controls. The State, however, lacks extensive authority to require controls.
The State has much more leverage when issuing construction permits to include air quality requirements, such
as fugitive dust controls, than when issuing and re-issuing operating permits. Tb a large extent, local agencies
have the primary responsibility for establishing requirements, extracting commitments to control emissions,
and issuing permits. Thus, commitments to use dust suppression measures may be somewhat informal which
makes any legal enforcement by the State difficult In addition, facilities are then not bound by any
enforceable requirement to continue air emission control measures under less than ideal conditions such as
inclement weather or problems with vendors of dust suppression equipment
Requirements for air quality control have been formally and informally arranged, with the Bethlehem
facility in Burns Harbor, and formally established through rulemaking for the US Steel facility in Gary. Most
requirements for control of paniculate matter emissions are established through rulemakings that specify
requirements for a facility by name.
-------
Appendix D-2: Existing Regulatory Controls D-2-11
The steel industry and the State differ on whether it is the responsibility of the steel mills or the slag
processors regarding dust suppression measures on.slag that is to be re-processed. Certain slag processors
have submitted dust suppression plans, though the State does not have the authority to require these plans,
to approve or disapprove plans, or to establish specific requirements. The State hopes to gain more significant
regulatory control over the numerous slag processors operating at the site of the four primary steel mills.
Kentucky
Two facilities generate special wastes from mineral processing in Kentucky. One facility is a fully
integrated ferrous facility generating iron and basic oxygen furnace steel slag and air pollution control dust.
The other facility generates process wastewater and fluorogypsum from hydrofluoric acid production.
Exhibit D-2-8 shows the names and locations of the two mineral processing facilities in Kentucky.
Exhibit D-2-8
Mineral Processing Facilities Located in Kentucky
and the Waste Streams They Generate
Facility
Armco, Inc.
Atochem (Pennwalt)
Location
Ashland
Calvert City
Sector
Ferrous
Hydrofluoric Acid
Waste Stream*
1 . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furnace APC
Dust/Sludge
1 . Fluorogypsum
2. Process Wastewater
Two facilities in Kentucky generate wastes from the processing of ores and minerals. Armco generates
ferrous wastes, and Atochem generates fluorogypsum and process wastewater from hydrofluoric acid
production.
Mineral processing wastes are not subject to hazardous waste regulation in Kentucky. Certain solid
waste management, water, and air regulations, as well as provisions in a proposed residuals rule, apply to
ferrous wastes and hydrofluoric acid wastes similarly. Tb a large extent, however, these wastes are regulated
on a site-specific basis.
Landfilling of solids is permitted under existing solid waste regulations. Kentucky officials have the
authority to conduct inspections and enforcement activities, and to impose penalties for violations. Solid waste
management facilities are required to have financial assurance for closure. Both ferrous wastes and
hydrofluoric acid wastes may be regulated more strialy after the implementation of a residuals rule, which may
be effective as early as the middle of July 1990. Landfills may be required to conduct additional ground-water
monitoring and undertake formal closure activities under the requirements of the proposed residuals rule.
In addition, the rule includes restrictions on the transportation of waste. Despite these general requirements,
ferrous wastes and hydrofluoric acid wastes are primarily regulated on a site-specific basis.
Iron and steel slag and iron and steel air pollution control dust are managed separately and thus
regulated differently in Kentucky. According to one State official and the Armco response to the SWMPF
Survey, 100 percent of BF slag generated by the Armco facility in Ashland is sold to a processor (Heckett Co.)
and 90 percent of steel slag is sold for processing, with the remaining ten percent returned to the sinter plant.
According to another State official, slag which is not re-processed or otherwise used is disposed of in one of
the two inert landfills Armco maintains on-site. These landfills are required to manage waste in an
environmentally protective manner by employing and maintaining a monthly cover, operating according to a
plan and permit, and using run-on and run-off controls and drainage ditches. Although State officials noted
-------
D-2-12 Appendix 0-2: Existing Regulatory Controls
that there have been problems in the past with leaching of contaminants from slag use, the use of slag is not
subject to regulation. If it is demonstrated that leaching has occurred because of the use of iron or steel slag,
the facility could be cited, and enforcement through the waste management or water divisions could follow.
Regulation of air pollution control dust and sludge is somewhat more strict. The Armco facility
disposes dust and sludge off-site at a residential landfill in Boyd County. Residential landfills are subject to
requirements for ground-water monitoring.
The Atochem, Calvert City facility operates the only permitted "hydraulic landfill" (i.e., the facility's
surface impoundment) in the State. The landfill is not designed to discharge to ground or surface water.
Ground-water monitoring wells are located around the landfill (fluorogypsum pond) in accordance with the
existing solid waste regulations. The fluorogypsum disposal site will be, after the promulgation of the
proposed rule, regulated as a residual landfill. When renewing its solid waste permit, the facility will be
required to obtain a permit for a residual landfill, continue to show that the waste is non-hazar" ?us, and
possibly upgrade the present ground-water monitoring operations. State officials noted that the - rial has
a low permeability and that there is little possibility for contaminant transport. Even if thtu vere no
attenuation of contaminants, however, leachate would still not exceed point-source discharge limits, according
to State officials.
State officials added that a CERCLA workforce is evaluating all closed landfills that were allowed to
operate without permits, and that this investigation includes two sites at the Calvert City facility.
Water protection requirements in Kentucky apply similarly to both Armco and Atochem, although
hydrofluoric acid process wastewater is the only waste stream subject to specific controls. At this time, the
Atochem facility has a NPDES permit for discharge of process wastewater (State officials believe, however,
that 100 percent of hydrofluoric acid process wastewater is recycled at the Atochem facility). Dikes located
around the fluorogypsum pond provide some run-off control.
In order to obtain a NPDES permit, the hydrofluoric acid process wastewater or any iron and steel
plant discharges must be characterized, and this information must be submitted to the State. The permit
application also must include the flow rate, how much effluent is discharged, the mixing zone of the effluent,
the size of the stream to which effluent will be discharged, the pH, and the concentration of suspended solids.
Permitted facilities operate under a self-monitoring system and must submit reports on effluent on
a periodic basis, ranging from several times daily to monthly. Each facility has an average and maximum value
it must achieve. Permits are in effect for five years unless a facility undergoes modification. Permits are
drafted by the Kentucky ground-water branch and then subject to a 30 day public comment period. After final
review and modification, permits are issued in final form.
The Atochem facility must meet standards for stormwater run-off from its operating and closed
fluorogypsum ponds. Similarly, it is likely that Armco must meet standards for stonnwater run-off from any
slag piles or APC dust and sludge waste piles or surface impoundments. Kentucky officials monitor surface
water discharges and impacts to ground water. The facility must divert stormwater to prevent contamination
of ground or surface water and monitor these discharges for hazardous characteristics using a chemical
measuring device. Some facilities, including the Atochem and Armco, may also do toxicity testing using
aquatic organisms; this test would apply mainly to process wastewaters. The Atochem facility recently renewed
its permit, which includes human health and aquatic life discharge limits.
The nature of the ferrous wastes results in stricter fugitive dust requirements for the Armco facility
than for management of the predominantly liquid hydrofluoric acid wastes at the Atochem facility. Facilities
such as Atochem must meet general requirements regarding fugitive dust. Requirements are based on visual
observation and rely on the discretion of the inspector, according to State officials. The Calvert City facility
has certain fluorospar kilns and waste piles that it may be required to revegetate, although State officials were
not aware of any fugitive dust problems at the facility. As stated above, the nature of fluorogypsum as
currently managed effectively precludes any fugitive dust problems.
-------
Appendix D-2: Existing Regulatory Controls D-2-13
Strict air pollution controls are employed at the Armco facility to prevent fugitive dust emissions.
At the time when slag is tapped from the blast furnaces, the molten slag is hit with "big sprays." The slag is
dumped into a two and one-half ton end loader, which then goes through a truck watering station where the
slag is "quenched." The trucks then travel along an oiled road surface (another dust suppression mechanism)
to the Heckett processing facility. A controlled precipitator captures dust from each of the basic oxygen
furnaces, which is then hauled in covered trucks to a private landfill. Blast furnace air pollution control waste
is eventually hauled to the same landfill, yet is apparently generated as a sludge which is hauled to ponds and
then loaded into trucks. Kentucky air officials have the authority to inspect the Armco facility and do so on
a regular basis.
Louisiana
In Louisiana, there are two alumina facilties, one hydrofluoric acid facility, and three phosphoric acid
facilities, as shown in Exhibit D-2-9.
Exhibit D-2-9
Mineral Processing Facilities Located in Louisiana
and the Waste Streams They Generate
Facility
Agrico
Agrico
Arcadian
Kaiser
ORMET
Allied-Signal
Location
Donaldson
Uncle Sam
Gefsmar
Gramercy
Burnside
Qeismar
Sector
Phosphoric Acid
Phosphoric Acid
Phosphoric Acid
Bauxite
Bauxite
Hydrofluoric Acid
Waste Stream*
1 . Process Wastewater
Z. Phosphogypsum
1. Process Wastewater
2. Phosphogypsum
1. Process Wastawater
2. Phosphogypeum
1. Red and Brown Muds
1 . Red and Brown Muds
1 . Process Wastewater
2. Phosphogypsum
The Louisiana Hazardous Wfrste Management Regulations exclude "solid waste from the extraction,
beneficiation, and processing of ores and minerals, including coal, phosphate rock, bauxite, and overburden
from the mining of uranium ore" from regulation as hazardous waste.
In Louisiana, phosphogypsum and process wastewater from phosphoric acid production, fluorogypsum
and process wastewater from hydrofluoric acid, and red muds from alumina production are considered
industrial wastes and are subject to the requirements of the Louisiana Solid Waste Management and Resource
Recovery Law and the Louisiana Solid Waste Regulations. The regulations outline general site requirements
for all solid waste disposal facilities, including provisions for soils (e.g., stability, low permeability), hydrological
characteristics, locational characteristics (e.g., proximity to critical environmental areas), security, safety, and
monitoring of incoming wastes.
According to a State official, there are no express requirements in the regulations for phosphogypsum
stacks or fluorogypsum stacks. Instead, they are subject to the majority of the industnal solid waste landfill
requirements of the solid waste regulations. The stacks are not required to adhere to the daily cover
requirements for landfills. Phosphogypsum stacks are required to have controls that contain run-off from
operating areas. According to a State official, liners are required for new impoundments and stacks; "new"
applies to facilities built after July, 1983. During closure, the owner or operator is required to emplace either
-------
D-2-14 Appendix 0-2: Existing Regulatory Controls
a final cover or alternative erosion control measures if installation of a final cover is infeasible. The
owners/operators must meet financial responsibility, requirements for closure and post-closure care.
The impoundments that receive the process wastewaters and red muds must adhere to specific
requirements for surface impoundments outlined in the regulations. Under these requirements, owners or
operators must ensure that each surface impoundment has the following: controls so that surface run-on will
be prevented from entering the facility; an artificial or natural liner on the bottom and sides of the
impoundment which is equivalent to three feet of clay with the coefficient of permeability of IxlO"7 cm/sec for
ground-water protection; design and operation standards that prevent overtopping by overfilling, wave action,
or storms; a perimeter levee to minimize wind and water erosion; and weekly inspections. Ground-water
monitoring around the impoundments is required. For surface impoundments, samples must be analyzed for
total dissolved solids, plus three other parameters intrinsic to the waste source. The liner requirement applies
to "new" surface impoundments (i.e., those built after July, 1983).
Closure and post-closure care requirements for surface impoundments also are addressed in the
regulations. The impoundments must be dewatered. If the remaining solids are removed, no other closure
or post-closure care requirements apply. If solids remain in the impoundment, owners/operators must adhere
to the closure and post-closure requirements for industrial solid waste landfills. Owners/operators must meet
financial responsibility requirements for closure and post-closure care of surface impoundments.
Permits are required in order to construct a new facility or make major modifications to an existing
facility. An interim permit may be issued to the operator of an existing facility (any facility collecting or
receiving solid waste and not closed prior to January 20, 1981) while an application is being processed, or
while a facility or site is being modified. According to the State official, the permit application, after review,
essentially becomes the permit. If the Department disagrees with something in the application, the
Department attaches conditions to the application that must be met. The Arcadian facility and the two Agrico
facilities that produce phosphoric acid, the Allied Signal hydrofluoric acid facility, and both the Kaiser and
ORMET alumina facilities have "standard permits," which means each facility has fulfilled all of its permitting
obligations and met all the requirements of the regulations. According to the State official, the ORMET
facility has a standard permit for its red mud lake and two redTnud impoundments are being closed. The State
official explained that when the Department of Environmental Quality considers bringing a facility into the
program, it has two options for a unit, including upgrade or closure. If the State determines that it is not
worthwhile to upgrade units, these units typically are closed.
The Department has on-site inspection authority. The authority for administrative and enforcement
activity is outlined in the Environmental Quality Act, Sections 212 and 225. The Department can issue
consent orders, administrative orders, and notices of violation, depending on the nature of the problem. As
an example, the State official noted that if the Department notices an activity it wants changed, even if that
activity does not necessarily constitute a violation, it may issue a consent order.
Because Louisiana does not have an EPA-approved NPDES program, Federal NPDES permits are
required for surface water discharges. All three phosphoric acid facilities in Louisiana have NPDES permits.
The Allied-Signal facility discharges to the Mississippi River through permitted NPDES outfalls. In addition,
under the Louisiana Water Pollution Control Regulations, a permit from the State is required in order to
discharge leachate or run-off to surface waters from facilities. Permits are administered through the Louisiana
^ater Discharge Permit System.
The Louisiana Air Pollution Control Regulations (LAPCR) regulate and control the discharge of
emissions into the air resources of the State and incorporate the Federal New Source Performance Standards.
Louisiana also has adopted the Federal primary and secondary ambient air quality requirements. All facilities
are required to obtain a Louisiana Air Emissions Permit, which contains site-specific requirements based on
the regulations and the New Source Performance Standards. According to a State official, a facility must be
operated in a manner to minimize fugitive dust. If any phosphoric acid, hydrofluoric acid, or alumina facility
were to have a potential problem with dust from either a stack or impoundment, the owner or operator would
-------
Appendix D-2: Existing Regulatory Controls D-2-15
be required to remedy that problem. Options for fugitive dust control are outlined in the regulations and
include, among other things, application of chemicals, asphalt, or water.
Mississippi
There are three mineral processing facilities in Mississippi that are under study for this report: two
titanium tetrachloride facilities that generate chloride process waste solids, and one phosphoric acid processing
facility that generates process wastewater and phosphogypsum. The facilities, their locations, and the waste
streams they generate are presented in Exhibit D-2-10.
Exhibit D-2-10
Mineral Processing Facilities Located in Mississippi
and the Waste Streams They Generate
Facility
duPont
Kerr-McGee
Nu-South Industries
Location
Pass Christian
Hamilton
Pascagoula
Sector
Titanium Tetrachloride
Titanium Tetrachloride
Phosphoric Acid
Waste Streams
1 . Chloride Process Waste Solids
1 . Chloride Process Waste Solids
1 . Process Wastewater
2. Phosphogypsum
The Mississippi Hazardous Waste Management Regulations adopt the Federal exemption for wastes
from the extraction, beneficiation, and processing of ores and minerals from hazardous waste regulation.
Therefore, chloride process waste solids are not regulated as hazardous waste in Mississippi.
The Mississippi Solid Waste Management Regulations contain a provision that exempts solid wastes
generated and processed on the generator's property, in a processing facility owned and operated by the
generator, from regulation as solid waste [MSWMR Sec. A(2)(f)]. The focus of solid waste regulation
implementation has been on municipal solid waste and hazardous waste. There are requirements for solid
waste landfills, including liners, ground-water monitoring, and erosion and ponding control. Apart from this
focus on municipal solid waste and hazardous waste, the State policy is to allow generators of non-hazardous
industrial waste to dispose of the waste on-site without a permit as long as the method of disposal does not
create an environmental or public health hazard. The State can and does conduct on-site inspections, and has
in some cases required industrial solid waste generators to obtain permits for the disposal of their wastes.
The State does have an approved NPDES program. In addition to NPDES permits for all point
source discharges in the State, the State also issues UIC permits, and State permits for discharges to
pretreatment works, treatment works where no discharge occurs, and generally where NPDES and UIC permits
do not apply. These regulations cover all discharges from industrial facilities, including mineral processing
facilities.
The two titanium tetrachloride facilities in Mississippi under study for this report are the duPont
facility in Pass Christian, MS and the Kerr-McGee facility in Hamilton, MS. The duPont facility, which uses
the chloride-ilmenite process, treats its chloride process waste solids in an on-site surface impoundment and
disposes of them in on-site waste pits. It has no solid waste permit for this process or for disposal. It does
have a NPDES permit for discharge to surface water from large storage ponds that collect contact cooling
water from the production process and surface run-off from all the disposal pits and surface impoundments
at the facility. In the past, there had been ground-water monitoring wells on-site, but they are not mandated
by the NPDES permit and may not currently be used. The facility is required to monitor the constituent
concentrations of its effluent on a regular basis. The Kerr-McGee facility uses the chloride process, and
generates process wastewater and chloride process waste solids. The facility has no solid waste permit
-------
D-2-16 Appendix D-2: Existing Regulatory Controls
addressing its co-management of these wastes on-site. Although this facility's NPDES permit closely resembles
that of the duPont facility, Kerr-McGee is permitted to discharge its process wastewater while duPont is not.
The duPont facility currently injects its process wastewater into the ground via three on-site deep wells.
The phosphoric acid production facility in Mississippi under study for this report is the Nu-South
Industries facility in Pascagoula, MS. This facility was recently purchased by Nu-South Industries from
Mississippi Chemical Company, which had operated the facility for over 30 years. Since the purchase, the
facility has not been in operation and Nu-South has, in fact, filed for bankruptcy. There were no solid waste
permits for the facility, but its NPDES permit was transferred to the new ownership. This permit is still in
effect, but the only management activities regarding the surface impoundment atop a large phosphogypsum
staa vhich remains at the site are carried on with money provided to the trustee of the facility by Mississippi
Chemical Company. According to State officials, inactive or abandoned industrial sites with non-hazardous
waste are regulated only in response to demonstrated public health or environmental hazards.
Missouri
Three facilities generate special wastes from mineral processing in Missouri. Each of these facilities
generates lead slag. Primary lead slag is the only special waste from the processing of ores and minerals
generated in Missouri. Exhibit D-2-11 shows the names and locations of the three lead facilities in Missouri.
Exhibit D-2-11
Mineral Processing Facilities Located in Missouri
and the Waste Streams They Generate
Facility
Asarco
Doe Run
Doe Run
Location
Glover
Herculaneum
Boss
Sector
Lead
Lead
Lead
Waste Streams
1 . Slag
1. Slag
1. Slag
Historically, lead slag has not been regulated under either hazardous waste or solid waste rules in
Missouri. The Metallic Minerals \Vfrste Management Act passed in 1989, (HB 321), requires generators of
lead slag to submit a permit application for management of a number of mining and mineral processing wastes,
including lead slag. Permits for existing operations, which were due by February 28, 1990, must include the
following: 1) operating information such as maps, proof of ownership, time tables, and location of monitoring
wells; 2) a detailed closure plan (and post-closure plan, if applicable), including information on recommended
future land uses and plans for revegetation to fit the local environment; 3) an inspection and maintenance
plan; and, 4) provisions for financial assurance. Closure plans must be reviewed every five years; plans must
include provisions for inspection by State officials. Only active sites are subject to the requirements of the
Act; old and abandoned sites are specifically excluded.
Until regulations are developed to implement the Act, owners are not required to meet specific
criteria or management requirements beyond the requirement to submit closure plans as described above. The
statute contains provisions for enforcement such as injunction and civil penalties. Because the first permitting
cycle has not yet been completed, these provisions have not been tested through the failure of a facility to
comply with the requirements, or expanded through development of regulations.
In Missouri, owners and operators must obtain a NPDES permit for storm water discharges from slag
piles. Therefore, all slag piles should be equipped with run-on/run-off controls. In addition, although lead
smelting facilities are required to obtain air quality permits, specific requirements are not included for slag
piles. Any dust suppression measures undertaken by facilities are optional.
-------
Appendix D-2: Existing Regulatory Controls D-2-17
Montana
Two facilities generate special wastes from mineral processing in Montana. One of these facilities
generates lead slag from primary lead production. The other facility generates elemental phosphorus slag.
Exhibit D-2-12 shows the names and locations of the two mineral processing facilities in Montana.
Exhibit D-2-12
Mineral Processing Facilities Located in Montana
and the Waste Streams They Generate
Facility
Asarco
Stauffer
Location
East Helena
Silver Bow
Sector
Lead
Elemental Phosphorus
Waste Streams
1 . Slag
1. Slag
Two special wastes from the processing of ores and minerals, lead slag and elemental phosphorus slag,
are generated by facilities located in Montana. Regulation of lead and elemental phosphorus slag is virtually
identical because both wastes are slags and mineral processing waste is not subject to extensive regulation in
the State.
Montana has adopted the Federal exclusion from hazardous waste regulation for wastes from the
extraction, beneficiation, and processing of ores and minerals.
According to State officials, the Montana solid waste regulations exempt from licensing wastes that
are managed on-site. Thus, although lead and elemental phosphorus slags are considered solid waste, as long
as slag is managed on-site, a slag pile would not be subject to regulation unless it causes a nuisance or
provokes a health hazard. If lead or elemental phosphorus slag were managed off-site, the off-site facility
would be subject to solid waste management requirements such as licensing.
Montana does not regulate storm water discharges from slag piles under water quality standards;
NPDES permits are not required and slag piles are apparently not required to have run-on/run-off controls.
In addition, no surface water or ground-water protection requirements appear to apply to lead slag disposal
units.
Although both lead and elemental phosphorus facilities in Montana are required to obtain air quality
permits, specific requirements are not included for slag piles. Any dust suppression measures undertaken by
facilities related to slag are optional.
New Mexico
There are two mineral processing facilities in New Mexico that are under study for this report. The
two facilities are copper processing facilities. Both of the facilities produce furnace slag from copper
processing, but neither produce slag tailings or calcium sulfate sludge. The facilities, their locations, and the
waste streams they generate are presented in Exhibit D-2-13.
-------
D-2-18 Appendix D-2: Existing Regulatory Controls
Exhibit D-2-13
Mineral Processing Facilities Located in New Mexico
and the Waste Streams They Generate
Facility
Phelps Dodge
Phelps Dodge
Location
Hurley
Play as
Sector
Copper
Copper
Waste Streams
1. Slag
1 . Slag
The New Mexico Hazardous Waste Management Regulations adopt the Federal exemption from
hazardous waste regulation for wastes from the extraction, beneficiation, and processing of ores and minerals.
Consequently, none of the three special wastes from primary copper processing are regulated as hazardous
wastes.
The New Mexico Solid Waste Management Regulations initially defined industrial waste as waste in the
nature of residential, commercial or institutional waste generated at an industrial establishment, but not waste
resulting from the industrial process. Subsequently, a new set of solid waste regulations was enacted in March
1990. The new regulations specifically exempt wastes from the extraction, beneficiation, and processing of ores
and minerals from solid waste regulation.
The New Mexico Environmental Improvement Division is empowered by the New Mexico >flfoter Quality
Standards and the New Mexico Water Quality Regulations to establish effluent limitations, to require the
highest and best degree of wastewater treatment available to protect the designated uses of State waters, and
to enforce both State and EPA discharge permit conditions. The State does not have an approved NPDES
program. All persons who may cause or allow effluent or leachate to discharge so that it may move directly
or indirectly into the ground water must have a discharge plan approved by the Division. The plans are
evaluated on the basis of their adequacy in meeting ground-water quality standards. There are several mining
and mineral processing-related exceptions from the universal discharge plan requirement including leachate
from the direct natural infiltration of precipitation through disturbed materials (unless the State determines
a public health hazard would result) and leachate that is otherwise regulated by the Solid Waste Management
Regulations. The State can and does conduct on-site inspections and enforcement actions, including
remediation activities. The New Mexico Air Quality Standards and Regulations require all sources of air
contaminants to have a permit in order to operate. Although emission limitations for a variety of mineral
processing operations are specified, copper processing is not mentioned specifically.
The slag generated at both the Hurley and Playas facilities is not covered under any provision of the
State's solid or hazardous waste regulations. Both facilities have discharge plans for protection of the ground
water, but the plans do not address slag disposal.
North Carolina
North Carolina has one sodium dichromate facility and one phosphoric acid facility, as shown in
Exhibit D-2-14.
In its Hazardous Waste Management Regulations. North Carolina adopts the Federal definition of
hazardous waste, and as a result, "solid waste from the extraction, beneficiation and processing of ores and
minerals (including coal), including phosphate rock and overburden from the mining of uranium ore" are
exempt from regulation as hazardous waste in North Carolina.
-------
Appendix 0-2: Existing Regulatory Controls D-2-19
Exhibit D-2-14
Mineral Processing Facilities Located in North Carolina
and the Waste Streams They Generate
Facility
Occidental Chemical
Texasgulf
Location
Castle Hayne
Aurora
Sector
Chromite
Phosphoric Acid
Waste Streams
1. Roast/Leach Ore
1 . Process Wastewater
2. Phosphogypsum
According to State officials, all residuals from facilities with NPDES permits are exempt from the
North Carolina Solid Waste Management Act and pursuant regulations.2 Instead, these wastes are regulated
under "non-discharge" permits under the North Carolina Water Pollution Regulations. Under these
regulations, a NPDES permit is required to discharge wastes from an outlet, point source, or disposal system
into State surface waters. North Carolina has an EPA-approved NPDES program.
North Carolina has issued non-discharge permits to Occidental's chrome facility that require zero
discharge from the impoundments used for disposal of the treated residue. In addition, the permit
requirements include weekly EP toricity testing, ground-water monitoring, a compliance boundary where water
quality standards must be met, and operation by personnel certified by the State.
For the Texas Gulf facility, much of the disposal activity is addressed under the mining regulations.
From 1963 until about two and one half years ago, Texas Gulf placed its phosphogypsum in permanent stacks.
According to the State official, they currently stack the phosphogypsum only temporarily. The phosphogypsum
is then transported and mixed with clay and sand tailings and put back into mined-out areas. This activity is
done under the facility's mining permit. According to the State official, it is Texas Gulfs position that
phosphogypsum is not a waste, but rather a by-product Therefore, the phosphogypsum stacks, both new and
old stacks, are not considered waste piles by the Solid Waste Section, and historically, have not been regulated
as such. According to the State official, if these stacks fell within the jurisdiction of the solid waste program,
the low pH that they exhibit might result in their regulation as hazardous wastes.
According to the State official, North Carolina has adopted Federal effluent limitations guidelines
which designate the phosphoric acid process as "closed loop," stipulating that it may not result in any
discharge. The Water Quality Section uses best professional technical judgments and best available technology
to achieve zero discharge. If zero discharge cannot be achieved, however, the phosphoric acid facilities must
abide by State standards for ground water and surface water, as outlined in the North Carolina Water Quality
Standards (15 NCAC 2B.02 and .01). These regulations do not allow degradation of the State's waters below
water quality levels necessary for existing and future uses.
In all instances, for phosphoric acid facilities, treatment or discharge of wastewater is handled by
discharge permits. As noted, North Carolina has an EPA-approved NPDES program. Under the North
Carolina Water Pollution Control Regulations, a NPDES permit is required to discharge wastes from an
outlet, point source, or disposal system into State surface waters.
The Water Quality Section of the Division of Environmental Management has the primary jurisdiction
for the disposal of phosphogypsum and process wastewater from phosphoric acid production and treated
roast/leach ore residue from sodium dichromate production. This office has the authority to perform on-site
North Carolina Solid Waste Management Regulations state that the term solid waste does not include "wastewater discharges
and the sludges incidental thereto and generated by the treatment thereof which are point sources subject to permits granted under Section
402 of the Federal Water Pollution Control Act, as amended (PJ_ 92-500) and permits granted under G.S. 143-215.1 by the Environmental
Management Commission; except that any sludges that meet the criteria for hazardous waste under the Federal Resource Conservation
and Recovery Act (P.L. 94-580) as amended, shall also be a solid waste" [NCAC, Title 10, Chapter 10G, Section .0101(36)(iii)J.
-------
D-2-20 Appendix D-2: Existing Regulatory Controls
inspections. North Carolina General Statute (143-215.2) addresses and authorizes different types of "special
orders," including Consent Orders.
A State official described a situation at Texas Gulf in which a Consent Order was issued.
Depressurizing water for the mine flowed through the stacks. As it passed through one of the ditches around
the phosphogypsum, the water became contaminated with fluorides and phosphorus. The Water Quality
Section issued a Consent Order. Texas Gulf subsequently "closed the loop" (except for the disposal of cooling
water in ponds) to ensure no mingling of waters. Texas Gulf also was required to line all their ditches. As
a result of ground-water problems from the ponds and the stacks, another Consent Order was issued. Texas
Gulf claims that their ponds are already lined. To address the problem, therefore, they are installing a slurry
wall of salted bentonite around these ponds to stop lateral movement to surface water.
A liner or impervious layer is required under all new phosphogypsum stacks in order to reduce
migration. At the Texas Gulf facility, according to the State official, no areal expansion of stacks is occurring;
instead, the old stacks are typically being drawn down.
Under the North Carolina Air Pollution Control Regulations, the State has adopted the Federal
standards for ambient air quality and new source performance standards. According to a State official, the
Texas Gulf facility has 21 air permits, none of which specifically mention or address the stacks or ponds.
Because the material in gypsum stacks forms a crust, State officials believe that the stacks have not posed a
major dust problem, and they have not been actively subject to requirements in the air program. Currently,
Occidental's surface impoundment used for disposal of the treated roast/leach residue is not subject to specific
requirements in the facility's air permit.
In the future, however, the State official mentioned a recently promulgated air regulation that may
affect the phosphogypsum stacks and ponds and chrome waste impoundments. When Texas Gulf or
Occidental modifies its facility and applies for a new permit, the stacks or impoundments may become subject
to more stringent air regulation under the Control of Toxic Air Pollutants (ISA NCAC 2D Section .1100) and
the permitting requirements for toxic air pollutants (IS NCAC 2H Section .0610). This regulation addresses
certain air toxics, including radionuclides and fluorides, which can be released as air contaminants from
phosphogypsum stacks and ponds.
North Dakota
As seen in Exhibit D-2-15, the Dakota Gasification facility in Beulah, North Dakota is the only facility
in the State under study for this report.
Exhibit D-2-15
Mineral Processing Facilities Located in North Dakota
and the Waste Streams They Generate
Facility
Dakota Gas
Location
Beulah
Sector
Coal Gasification
Wast* Stream*
1 . Process Wastewater
2. Gasifier Ash
Under the North Dakota Hazardous Waste Management Act, "solid waste from the extraction,
beneficiation, and processing of ores and minerals, including phosphate rock and overburden from the mining
of uranium ore" is exempt from regulation as hazardous waste. North Dakota has an EPA-approved RCRA
Subtitle C program.
The North Dakota Solid \\frste Management Regulations delineate standards for several disposal
operations, including sanitary landfills, incinerators, special use disposal (i,e., construction and demolition
-------
Appendix D-2: Existing Regulatory Controls D-2-21
wastes and incineration residue), and other methods of disposal. The North Dakota State Department of
Health and Consolidated Laboratories, in its comment on the September 25,1989 proposed mineral processing
rule (54 FR 39298), stated that wastes from the Dakota Gasification facility are regulated as "special wastes"
(i.e., special use) under the State's Solid Waste Management and Land Protection Act and the Solid Waste
Management Regulations.3 According to a State official, the Department is given broad authority under the
Act to implement the pursuant rules, so long as its actions are within the intent of the Act
Under authority of the Special Use Disposal Standards (33-20-05-02), the Department of Health
determines the appropriate requirements for each site and outlines them in a permit. Permits are required
in order to construct (33-20-06-08) and operate (33-20-07-01) a solid waste disposal facility. The State official
described three permitted disposal facilities, two landfills for gasifier ash, one of which is closed, and one for
construction debris. The ash landfills are required to have liners. The ash landfill currently in use has a
synthetically lined run-off system and a tiled drain system on the up-gradient side, outside of the pit.
One ash landfill has been closed, and the "permit is under post-closure." According to a State official,
at the time of closure the permit is amended and post-closure requirements are attached. Closure
requirements include eight feet of cover, where the lower three feet are of compacted clay. Post-closure
requirements include general maintenance and ground-water monitoring.
The facility's four ponds do not have permits, although proposed rules (see below) would require
them. At the time of the plant's construction, it was unclear whether the process waters would exhibit
hazardous characteristics, and subsequently which regulations would apply. The State official noted that a
conservative approach was taken and liners and other engineered controls were used.
The Department of Health has right-of-entry authority to conduct on-site inspections, issue
administrative orders (e.g., the Director may issue a Directive in emergency situations), enter into consent
agreements, and take civil or criminal action.
North Dakota is currently in the process of amending its solid waste regulations. The proposed
changes include specific requirements for surface impoundments, including permitting requirements, and
express post-closure care activities for all disposal facilities. Neither the current rules nor the amendments
have express financial responsibility requirements.
The North Dakota \\frter Pollution Control Act establishes the requirements for treatment of
industrial wastes. The North Dakota \Vater Quality Standards require that no untreated industrial wastes
which contain substances harmful to the public or which would degrade water quality can be discharged into
the State's waters. The North Dakota Pollution Discharge Elimination System Regulations establish
procedures for application, issuance, denial, modification, and revocation of permits for discharging pollutants
into the waters of the State. North Dakota participates in the National Pollutant Discharge Elimination
System (NPDES). NPDES permit holders are required to comply with Federal effluent limitations and other
applicable requirements of the \Vater Pollution Control Act.
The North Dakota Air Pollution Control Rules (NDAPCR) establish air quality standards and
emission requirements necessary to maintain air quality. NDAPCR outlines ambient air standards similar to
Federal standards, except for the sulfur oxides standard, which is more stringent. The rules include provisions
for restriction of paniculate matter from industrial processes. Permits are required in order to construct and
operate air contaminant sources. According to State officials, the air permit for the Dakota Gas facility does
not directly address the waste management units.
3 North Dakota State Department of Health and Consolidated Laboratories, MW2P-00002, Public Docket MW2P-FFFFF, U.S. EPA.
-------
D-2-22 Appendix 0-2: Existing Regulatory Controls
Ohio
Eight facilities generate special wastes from mineral processing in Ohio. Seven of these facilities are
fully integrated ferrous facilities generating iron and basic oxygen steel slag and air pollution control dust and
sludge (Wheeling-Pittsburgh, Steubenville did not generate steel wastes in 1988). The other facility generates
titanium tetrachloride process waste solids. Exhibit D-2-16 shows the names and locations of the mineral
processing facilities in Ohio.
Exhibit 0-2-16
Mineral Processing Facilities Located in Ohio
and the Waste Streams They Generate
Facility
Armco
LTV Steel
LTV Steel
US Steel
Warren Steel
Wheeling-Pittsburgh Steel
Wheeling-Pittsburgh Steel
SCM
Location
Middtetown
E. Cleveland
W. Cleveland
Lorain
Warren
Steubenville
Mingo Junction
Ashtabula
Sector
Ferrous
Ferrous
Ferrous
Ferrous
Ferrous
Ferrous
Ferrous
Titanium
Waste Stream*
t . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furance APC Dust/Sludge
1 . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furance APC Dust/Sludge
1. Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag*
4. Basic Oxygen Furance APC DusVStudge
1 . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furance APC Dust/Sludge
1. Blast Furnace Slag
2. Blast Furnace APC Oust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furance APC Dust/Stodge
1 . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
Steubenville did not generate steel wastes
in 1988
1. Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furance APC DusVStudgv
1 . Titanium Tetrachloride Process
Waste Solids
Seven lacilities in Ohio generate ferrous wastes; one facility generates titanium tetrachloride process
waste solids.
Ohio adopts the special exemption for wastes from the extraction, beneficiation, and processing of
ores and minerals. Therefore, neither the special ferrous wastes nor chloride process waste solids from the
production of titanium tetrachloride are regulated as hazardous wastes in Ohio.
-------
Appendix D-2: Existing Regulatory Controls D-2-23
According to the Ohio Solid 'Waste Disposal Regulations, slag is not a solid waste, and therefore slag
from iron and steel production is not regulated as a waste under Ohio waste management rules. The re-use
of slag, however, may be subject to specific statements or requirements.
Despite Ohio's adoption of the special waste exclusion, State officials indicated that iron and steel
APC dust or sludge as well as titanium chloride process waste solids could be regulated as a hazardous or solid
waste, depending on the results of EP toxicity tests. Assuming that in most instances hazardous waste
regulation is avoided through the special exemption, ferrous APC dust and sludge and titanium chloride
process waste solids would be regulated as solid waste. State officials explained that they use a strict
interpretation of solid waste, and that all wastes that are not hazardous or are not specifically excluded by the
solid waste regulations, such as slag, are regulated as solid waste. Thus, ferrous APC dust and sludge and
titanium tetrachloride process waste solids are regulated as solid, non-hazardous wastes according to State
officials.
Generators of solid waste are authorized to dispose of their waste in one of three ways: incineration,
landfill disposal, or composting. If wastes are incinerated on-site, then the facility does not need a permit.
\toter pollution control regulations apply to some aspects of the land application of sludges. Ohio has no
specific storage requirements for non-putrescible wastes; thus, the storage time for these wastes is open-ended,
according to State officials.
If APC dust and sludge or titanium tetrachloride waste solids were regulated as solid waste in
accordance with the interpretations of the State officials contacted, generators could only dispose of waste at
landfills meeting the revised requirements for solid waste management that became effective on March 1,1990.
All such wastes must meet the "paint filter test" to determine that there are no free liquids in the waste.
Furthermore, wastes must not display a characteristic of hazardous waste. The Ohio EPA has authorization
to inspect any licensed solid waste disposal facility. Inspections are carried out in cooperation with approved
local health departments. State officials noted that approved local health departments inspect industrial as
well as sanitary landfills. Violations of any aspect of the solid waste regulations are considered felonies and
are punishable by financial penalties of up to $25,000 and a three year jail term per day per violation.
As of March 1,1990 all licensed facilities must have met a variety of requirements, including ground-
water monitoring, placement of a final cap at closure, financial assurance, and a closure and thirty year post-
closure period (some exceptions were provided for financial assurance mechanisms). A call-in schedule has
been established for facilities to obtain new permits. Within two to three years all facilities will have reported
to the Ohio EPA for a revised permit.
Any site that has been in operation and closed over the last twenty years and is within 305 meters
(1,000 feet) of an occupied structure, must establish an explosive gas monitoring plan and network. The new
requirements include provisions for leachate collection systems and sedimentation basins for ground water;
any discharge into waters of the State must be made in accordance with a NPDES permit
Increasingly, according to State officials, landfills are subject to fugitive dust controls and require
permits. Typically, however, no air monitoring is required. Air and water controls are not required for slag
piles unless they are established through general provisions in the appropriate permits on a case-by-case basis.
State officials noted that they have broad site-specific authority to establish controls as needed.
Any restrictions on the use of wastes, such as slag, are usually established by the water program
through a monitoring plan which provides for an approved mechanism for waste management on most sites.
Officials in Ohio were able to provide a significant amount of information regarding the regulation
of waste at specific ferrous facilities as well as at SCM.
-------
D-2-24 Appendix D-2: Existing Regulatory Controls
The following describes the permits that Ohio State officials report ferrous metals production facilities
have, and the disposal methods that the facilities reported for blast furnace APC dust and/or sludge in the
National Survey of Mineral Processors:
Armco: • Has its own permitted solid waste disposal facility on-site.
• Reports that it disposes on-site.
LTV: • One or both of the LTV facilities brings its wastes to an independent landfill, ac-
cording to State officials.
• Reports that it disposes on-site.
US Steel: • Has no licensed landfill, according to State officials.
• Reports stockpiling waste in a waste pile.
Warren: • Has no licensed landfill, according to State officials.
• Reports stockpiling some waste in a waste pile and returning some or all to the
blast furnace.
W-P Steel: • (Mingo Junction and Steubenville) have no licensed landfills, according to State
officials.
• (Mingo Junction) reports sending waste off-site for disposal. (Steubenville did
not report its management of blast furnace APC dust and sludge.)
Because these facilities do not have permits for on-site landfills, under the solid waste regulations they may:
1) transport waste to a permitted landfill off-site; 2) incinerate waste; or 3) compost waste. It is extremely
unlikely that ferrous metal APC dust and sludge is incinerated or composted. Thus, according to State
officials' interpretation of the solid waste regulations, ferrous metals facilities should be disposing of APC dust
and sludge off-site. According to the responses summarized above, however, one facility disposes waste off-
site, and one facility disposes waste on-site in a permitted landfill. It is possible that a certain percentage of
APC sludge is sent to wastewater treatment works (e.g., a regulated lagoon that would meet requirements
established for wastewater treatment and water quality).
Ohio State officials report that the SCM facility is required to have an Ohio EPA solid waste permit
for landfilling their solid waste, and an annual operating license. The SCM waste is considered a solid waste.
SCM has applied for a license for a new solid waste management facility.
SCM did not have a solid waste management license in 1989. If the facility had a landfill or other
solid waste management operation in 1989, it was closed, according to State officials in Ohio. Regulated
alternatives for disposal of chloride solids include disposing solids in a closed-out lagoon that would be
regulated by the Division of Water Pollution Control, or in a hazardous waste management unit regulated by
Ohio's RCRA unit SCM reported in its response to the National Survey of Mineral Processors that all
titanium chloride process waste solids were recycled and none were disposed. This may have alleviated the
need to dispose of the waste solids in the absence of a licensed waste management facility.
As outlined above, Ohio does not have specific storage requirements that would apply to ferrous APC
dust and sludge or titanium process chloride waste solids. Thus, either of these wastes may escape regulation
if stored for extended periods of time. For instance, as described above, a number of ferrous facilities may
stockpile APC dust and sludge in waste piles indefinitely.
Pennsylvania
Seven facilities generate special wastes from mineral processing in Pennsylvania. Six of these facilities
are fully integrated ferrous facilities generating iron and basic oxygen steel slag and air pollution control dust
and sludge. One facility (US Steel, Fairless Hills) generates steel open hearth furnace slag and dust as well.
-------
Appendix D-2: Existing Regulatory Controls 0-2-25
The last facility generates zinc slag from primary zinc production. Exhibit D-2-17 shows the names and
locations of the mineral processing facilities in Pennsylvania.
The similar nature of zinc slag and ferrous wastes, as well as their joint classification in Pennsylvania
as residuals waste, results in virtually identical regulation of the ferrous and zinc mineral processing wastes.
Exhibit D-2-17
Mineral Processing Facilities Located in Pennsylvania
and the Waste Streams They Generate
Facility
Allegheny Ludlum
Bethlehem Steel
Sharon Steal
Shenango
US Steel
US Steel
Zinc Corporation of America
Location
Brackenridge
Bethlehem
Parrel
Pittsburgh
FaJrie*8Hffi»
Braddock
Monaca
Sector
Ferrous
Ferrous
Ferrous
Ferrous
Ferrous
Ferrous
Zinc
Waste Streams
t. Blast Furnace Slag
2. Blast Furnace APC Oust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furnace APC OusVStudge
1. Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furnace APC Dust/Sludge
1. Blast Furnace Slag
2. Blast Furnace- APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furnace APC OusVStudge
1 . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furnace APC Dust/Sludge
1 . Blast Furnace Slag
2, Blast Furnace APC Dust/Sludge
3. Baste Oxygen Furnace Slag
4. Basic Oxygen Furnace APC OusVStudge
5. Open Hearth Furnace Slag
6. Open Hearth Furnace APC Dust/Sludge
1 . Blast Furnace Slag
2. Blast Furnace APC Dust/Sludge
3. Basic Oxygen Furnace Slag
4. Basic Oxygen Furnace APC Dust/Sludge
1. Stag
At this time, ferrous metal production wastes and zinc slag are not regulated as either hazardous or
solid waste in the State of Pennsylvania, although these wastes are subject to regulation as residual waste.
Pennsylvania has exempted waste from the extraction, beneficiation, and processing of ores and minerals from
hazardous waste regulation. The solid waste regulations establish requirements for municipal waste which
generally consists of waste from municipal, residential, commercial and institutional establishments and
community activities. A proposed rule published February 24,1990 defines residual waste as:
Garbage, refuse, other discarded material or other waste, including solid, liquid, seraisolid
or contained gaseous materials resulting from industrial, mining, and agricultural operations
and sludge from an industrial, mining or agricultural water supply treatment facility, waste
water treatment facility or air pollution control facility, if it is not hazardous (Pennsylvania
Bulletin. Vol. 20, No. 8, 2/24/90).
-------
D-2-26 Appendix 0-2: Existing Regulatory Controls
State officials noted, as an indication that ferrous and zinc slag (and presumably ferrous APC dust
and sludge) would be regulated as residual waste under the proposed rule, that the proposed rule specifically
refers to a zinc slag pile ("mountain") as an example of residual waste (Pennsylvania Bulletin Vol. 20, No. 8,
2/24/90).
Presently, residual wastes are subject to regulation only at the point of disposal. A slag pile used as
a disposal site must have a permit. For the most part, however, wastes that are stored (for less than one year)
for later use or re-processing do not require a permit. The issue of storage leads to a conflict between industry
and State officials over how long storage (particularly of iron and steel slag) should be allowed without a
permit. Under the current regulations, storage in excess of one year constitutes illegal disposal. State officials
and industry still disagree on the implementation of this requirement. For instance, Bethlehem Steel in
Bethlehem, PA has at least one permit for disposal of residuals resulting from the production of iron and steel.
The State and Bethlehem disagree, however, on exactly how the permit should be interpreted, and thus iron
and steel slag is managed (or stored long term) without a permit. PADER has not required permits for the
zinc slag piles at the Monaca facility.
Under the current residuals regulations (Industrial and Hazardous Waste Disposal Sites. §75.38), a
permit is not required for transportation of solid waste off-site. Landfills that are permitted to receive residual
waste usually must have a permit for municipal waste with an amendment to receive residuals. These landfills
must use a system of double liners. Facilities must submit a permit application with a map; a leach test of
the waste; and a ground-water study, including the test results of three borings (at least one up- and one down-
gradient of the landfill). Phase II of the present residual rule requires landfills without liners to be above the
high-water table, and to have "renovating" soil underneath. After closure the site must be re-vegetated with
at least two feet of soil.
The Proposed Residual Waste Regulations, which may be finalized before the end of 1990, will
establish requirements for management of residual waste, including zinc slag and ferrous wastes, similar to the
Pennsylvania requirements for municipal solid waste management. State officials suggested that some
industries may be granted exemptions from the rule. In particular, exemptions could be granted for materials
that are re-used or re-processed. This could mean that iron and steel slag that is sold for processing, and
perhaps APC dust/sludge that is re-processed, could be exempted from regulation under the final residuals
rule.
The structure of the proposed regulations closely follow the Pennsylvania Solid Waste Regulations.
Depending on the results of leach tests, ferrous wastes as well as zinc slag may be placed in three different
types of landfills with various liner and other requirements. Generators will be required to file a form stating
that they have attempted to reuse and/or recycle the waste before disposal. As with the solid waste
regulations, permits will be required that include provisions for liners, leachate collection systems, monitoring
wells, and disposal of leachate. The proposed rule is also similar to the municipal waste regulations with
regard to prohibitions on where facilities may be located (e.g., within the 100 year floodplain, over areas of
limestone). It is unclear at this time how the final regulation will address inactive or abandoned sites,
although the proposed rule indicates that facilities without permits must document closure procedures within
a certain time frame.
Water regulation of ferrous metal production wastes and zinc slag in Pennsylvania is primarily
determined on a case-by-case basis. Although the State has authority to regulate discharge from slag waste
piles, State personnel indicated that discharge limits would most likely be established only if there was
evidence of contamination. If facilities channel run-off to lagoons or storm water discharge basins, the effluent
would be sampled and the facility would be required to meet certain contaminant limits. State drinking water
standards could also be invoked. Legally, facilities are not required to report on the storage of waste. Thus,
particularly in the case of iron and steel slag that is stored speculatively, the State might not have the authority
to require controls for a slag pile that is considered a storage pile for an indefinite period. Run-off from
unlined zinc or ferrous slag piles or ferrous APC dust and sludge piles could be very difficult to collect. Thus,
contaminated run-off may not be subject to any State controls.
-------
Appendix D-2: Existing Regulatory Controls D-2-27
Air regulations in Pennsylvania apparently apply mainly to processes that generate air emissions. The
department does not regulate air emissions from waste disposal and management activities. According to one
State official, if a complaint was received regarding fugitive dust emissions from a mineral processing type
facility, the inquiry would be referred to the waste management division.
Tennessee
There are three mineral processing facilities in Tennessee that are under study for this report: two
elemental phosphorus processing facilities that generate slag and one titanium tetrachloride facility that
generates chloride process waste solids. The facilities, their locations, and the waste streams they generate are
presented in Exhibit D-2-18.
Exhibit D-2-18
Mineral Processing Facilities Located in Tennessee
and the Waste Streams They Generate
Facility
duPont
Rhone-Pulenc
Occidental
Location
New Johnsonville
Mt Pleasant
Columbia
Sector
Titanium Tetrachloride
Elemental Phosphorus
Elemental Phosphorus
Waste Streams
1 . Chloride Process Waste Solids
1 . Furnace Slag
1 . Furnace Slag
The Tennessee Hazardous Waste Management Reeulations exempt wastes from the extraction,
beneficiation, and processing of ores and minerals from regulation as hazardous waste. Therefore, neither
chloride process waste solids nor elemental phosphorus slag are regulated as hazardous waste in Tennessee.
The Tennessee Solid Waste Regulations include industrial waste in its definition of solid waste;
however, prior to 1981, if the industrial waste was disposed on-site, then it was not regulated at all under the
solid waste regulations provisions. In 1981 new regulations were enacted that developed classes and design
and operating standards for on-site and off-site solid waste landfills. These regulations focused almost
exclusively on municipal solid waste (Class I landfills) and, although industrial waste landfills were designated
and regulated as Class II landfills, enforcement of the standards was not vigorous. Another new set of
regulations, however, came into effect in March 1990. These regulations require various management practices
for both Class I and Class II landfills, including approval of design drawings, contouring plans, liners, leachate
collection systems or other vertical buffers, and conditional ground-water monitoring. Any new solid waste
disposal facility must meet these requirements, while existing facilities are granted a four year grace period to
comply. The regulations also include requirements for financial assurance for closure and 30 years of post-
closure care. The State can and does conduct on-site inspections and enforcement actions. Most of the
resources are still focused on municipal solid waste, and it will take time to bring all the old landfills into
compliance with the new regulations.
The Tennessee Water Quality Control Act requires a permit for various activities, including the
development of any natural resource. The State has an approved NPDES program, and both the Occidental
Chemical facility in Columbia and the Rhone-Pulenc facility in ML Pleasant have obtained an NPDES permit
for discharges from their elemental phosphorus processing activities. The effluent restrictions are based on
the Federal effluent guidelines and on the level of treatment necessary to protect the receiving waters. The
permits include requirements for bio-monitoring and allude to the necessity of compliance with solid waste
management requirements in the Tennessee Solid Waste Disposal Act and the Tennessee Hazardous Wtste
Management Act The Occidental facility has a permit for an onsite industrial landfill which receives any non-
hazardous process wastes. The Rhone-Pulenc facility had an on-site permit, reached a point where they
-------
D-2-28 Appendix D-2: Existing Regulatory Controls
reprocessed some of the material in the waste pile, and then finally removed all waste from the site. It is the
current practice of both facilities to attempt to sell all the furnace slag that is generated to a reuser. The
quantity that is not sold is stockpiled on-site or landfilled at a permitted municipal landfill.
The titanium tetrachloride facility in Tennessee that is under study for this report is the duPont
facility in New Johnsonville, TN. It currently produces chloride process waste solids which are treated and
landfilled. The duPont facility has received solid waste landfill permits in 1977, 1978, 1981, 1986, and 1987
for a number of landfills which the facility utilizes to dispose of different types of waste generated on-site.
The facility also has a NPDES permit to discharge from the on-site surface impoundment used to treat process
wastes. This permit includes requirements for effluent monitoring, bio-monitoring, and for compliance with
State solid and hazardous waste management regulations in the management of any sludge or solid material
generated in the wastewater treatment process.
Texas
Texas has one phosphoric acid facility, two hydrofluoric acid facilities, one chrome facility, one
alumina facility, and three copper facilities, as outlined in Exhibit D-2-19.
Exhibit D-2-19
Mineral Processing Facilities Located in Texas
and the Waste Streams They Generate
Facility
Alcoa
Reynolds
American Chrome
ASARCO
ASARCO
Phelps Dodge
duPont
Mobil Mining
Location
Point Comfort
Gregory
Corpus Christ!
Amarillo
BPe»0
El Paso
LaPortft
Pasadena
Sector
Bauxite :
Bauxite
Chiomite ~~
Copper
Copper
Copper
Hydrofluoric Acid
Phosphoric Acid
Waste Stream*
1. Red and Brown Mud»
1 . Red and Brown Muds
1. Roast/Leach Ore
1. Stag
1. Slag
1. Slag
1. Process Wastewater
2, Fhjorogypsmn
1 . Process Wastewater
2. Phoephogypsum
Texas administers an authorized Subtitle C program. According to State officials, the Texas
Hazardous wastes program closely models RCRA, incorporating the Federal exclusion for mineral processing
wastes.
The Texas Industrial Waste Management Regulations establish standards for all aspects of the
management and control of municipal hazardous waste and industrial solid waste. According to State officials,
the mineral processing facilities in this State discussed in this report are subject to only one express
requirement, the notification stipulation (TAG, Title 31, §335(a),(f),(g)) of the regulations, in order to dispose
of their respective special wastes. Owners or operators were and are required to notify the Texas Water
Commission 90 days prior to the onset of disposal activities and may be required to submit any of the
following information: waste composition, waste management methods, facility engineering plans, and the
geology where the facility is located. Ninety-day advance notice for expansion or closure is also required. The
owner or operator is required to submit details of closure activities if requested by the Texas Water
Commission. The TWC can initiate enforcement activity against a firm if the closure activities are deemed
-------
Appendix D-2: Existing Regulatory Controls D-2-29
inadequate. Under the General Prohibitions (§335.4), owners and operators are not allowed to discharge
industrial solid waste into the waters of the State without specific authorization from the TWC.
According to State officials, of the three Texas copper facilties, only Asarco's El Paso facility is subject
to the requirements of these regulations. The Asarco facility in Amarillo and Phelps Dodge's facility in El
Paso reuse their copper slag and are not subject to these regulations.
No solid waste disposal permit is required at the facilities for disposing phosphogypsum and process
wastewater from phosphoric acid production; fluorogypsum and process wastewater from hydrofluoric acid
production; red muds from alumina production; treated roast/leach ore residue from sodium dichromite
production; and slag, calcium sulfate sludge, and slag tailings from primary copper processing because these
wastes are disposed on properties that are: (1) located within 50 miles of the facilities where they are
generated; and (2) owned or controlled by the owner/operator of the facilities. These facilities do have
"registrations", which are essentially inventories of the wastes generated and the manner in which they are
managed.
According to a State official, the regulations do not outline specific requirements for waste piles or
surface impoundments that manage industrial solid waste. Owners or operators are not expressly required to
place liners under the impoundments or to monitor ground-water. No closure and post-closure care
requirements exist for industrial solid waste piles or impoundments. These facilities are not required to
maintain a surety bond for financial assurance. The Texas Water Commission does provide ten Technical
Guidelines to advise owners/operators on appropriate liner materials and thickness, closure and post-closure
care activities, and site selection criteria, among other things. According to a State official, these Guidelines
merely advise and recommend; they do not outline requirements.
Texas does not have an EPA-approved NPDES program. The Texas Water Quality Acts state that
no person may discharge "industrial waste into or adjacent to any water of the State" without a permit. As
a result, Texas has a "dual permitting system" in which both a Federal NPDES and a State Wastewater
Discharge Permit are required for wastewater discharges to surface waters. The Mobil phosphoric acid facility
and the duPont hyrdrofluoric acid facility have both. According to a State official, Reynolds does not have
a NPDES permit and does not discharge to surface water. State permit requirements are outlined in the Texas
Wastewater Treatment Regulations. The regulations set specific discharge limits and stipulate that process
water must be retained in a surface impoundment capable of retaining maximum process flow without allowing
any discharge of pollutants. If discharge of these waters can be prevented by retention, a permit is not
required. According to a State official, a State discharge permit may address discharge of process wastewater
and discharge of contaminated or non-contaminated storm water ponds.
According to a State official, of the three copper facilities in this State addressed by this report, the
Asarco facility in El Paso is the only one that is subject to the Texas Water Quality Acts (Title 2, Chapter 26
of the Texas Administrative Code) and the Water Quality Standards for its slag disposal activities. The facility
must ensure there will be no contamination of ground water or surface water from slag disposal activities.
Run-off controls may be required in order to ensure compliance with this requirement. The water quality
standards set site-specific limits to ensure no degradation of water bodies. According to a State official, the
Asarco plant is under an enforcement order as a result of run-off from slag piles into the Rio Grande River.
High levels of arsenic were found. Asarco has since built an impoundment to collect storm water run-off.
The Texas Clean Air Act generally prohibits any emission without a permit, which is issued by the
Texas Air Control Board. In general, these permits for these facilities mainly address emissions from the
respective production processes, and waste disposal units are subject only to general requirements within the
permit. According to State officials, no requirements of the Act apply to the copper slag generated at
Amarillo or the Phelps-Dodge/El Paso facilities because any slag produced is reused and not disposed.
According to a State official, copper slag produced and disposed at the Asarco facility in El Paso also is not
subject to air requirements, such as water spraying and chemical sealing for control of fugitive dust from slag
piles, because the material hardens as it cools. Historically, fugitive dust has not posed a problem.
-------
D-2-30 Appendix 0-2: Existing Regulatory Controls
The Alcoa and Reynolds facilities have permits from the Texas Air Control Board. According to a
State official, the permit mainly addresses emissions from the production process and, therefore, the surface
impoundments at these facilities are subject only to general requirements within the permit. The State official
mentioned that at both facilities, the surface impoundments used for the disposal of the muds have needed
modifications. In both instances, the impoundments were drying up, causing fugitive dust emissions problems.
At Reynolds, there was an enforcement action for violation of a permit requirement, and the Air Pollution
Board has had complaints about the Alcoa/Point Comfort plant. Reynolds now uses a flooding process to
keep the muds completely under water, employing water from the nearby (saltwater) bay. Alcoa puts a coarse
river sand over areas that become dry in order to control emissions.
According to the State official, the Texas Clean Air Act is the main piece of legislative authority for
the Texas Air Pollution Board. Air Regulation No. 6 requires that a permit be obtained for construction or
modification of a facility that would emit air contaminants. According to the State official, by requiring a
permit to modify a facility, this regulation picks up the "grandfathered" facilities that were constructed prior
to the cutoff date for "new" facilities. The permit system requires the use of Best Available Control
Technology.
Utah
There are three mineral processing facilities in Utah that are under study for this report: a
magnesium facility that generates process waste water, a copper processing facility that generates slag, slag
tailings and calcium sulfate sludge, and a ferrous metals facility that generates iron blast furnace and steel
open-hearth furnace slag and APC dust and sludge. The facilities, their locations, and the waste streams they
generate are presented in Exhibit D-2-20.
Exhibit D-2-20
Mineral Processing Facilities Located in Utah
and the Waste Streams They Generate
Facility
Nagcorp
Kennecott
Geneva
Location
Rowley
Garfield
Orem
Sector
Magnesium
Copper
Ferrous
Waste Streams
1 . Process Wastewater
1. Slag
2. Slag Tailings
3. Calcium Sulfate Sludge
1 . Open-hearth Slag
2. Oeprvhearth APC Dust/Sludge
3. Iron Blast Furnace Slag
4. Iron Blast Furnace APC Dust/Sludge
According to State officials, the language of the Utah Solid and Hazardous \Vfrste Act was developed
in an attempt to provide a flexible scope with respect to both solid and hazardous waste regulation. The Utah
Hazardous Waste Regulations exempt wastes from the extraction, beneficiation and processing of ores and
minerals from regulation as hazardous waste and Section 26-14-6 of the Solid and Hazardous Waste Act
exempts those wastes from the scope of rulemaking as solid wastes. As a result, none of the special wastes
from primary copper processing, magnesium processing or ferrous mineral processing are specifically addressed
by the State solid or hazardous waste regulations.
Section 26-14-6, however, also provides for the regulation of extraction, beneficiation, and processing
wastes as hazardous wastes under certain conditions. More specifically, if a waste is either listed by EPA as
hazardous waste or is determined to be hazardous through the evaluation of the waste against hazardous waste
criteria, it will fall under the State's hazardous waste regulatory program. Once EPA makes a determination
-------
Appendix D-2: Existing Regulatory Controls D-2-31
on the status of the currently exempt special mineral processing wastes, those wastes will be addressed by the
State's regulatory program in accordance with that decision, i.e., Utah's position with respect to the 20 special
mineral processing wastes will parallel that of EPA.
The State has an approved NPDES program and the State Water Pollution Control Committee is
empowered by the Utah Water Pollution Control Act to promulgate water quality standards, classify State
waters, promulgate and enforce effluent limitations, and issue discharge permits. The State can and does
conduct on-site inspections, as well as enforcement actions if the facility is found to be in violation of a permit.
As of January 1990, new ground-water protection legislation was enacted and the new ground-water office is
in the process of designing ground-water discharge permits. No such permits have been issued as yet.
The tailings impoundment that is used for disposal of slag tailings at the one primary copper
processing facility in Utah also receives tailings from ore beneficiation, run-off, and discharges from all of the
facility's various operations. Discharge from the impoundment to a Class VI surface water is controlled under
the conditions of a NPDES permit. The designated use for a Class VI water in Utah is defined as "special,"
and waters with this classification are generally not suitable for any of the other beneficial uses designated by
the State. Discharge standards for Class VI receiving waters are determined on a case-by-case basis. The State
is in the process of negotiating a new NPDES permit that will include bio-monitoring provisions in addition
to existing BMP requirements. EPA Region VIII is taking a special interest in the terms of this permit
because of the designation of the receiving waters, under the Clean Wfcter Act, as a special impaired area.
The Utah Air Conservation Regulations specifically regulate sulfur dioxide air emissions and visible
compounds from the primary copper processing operations at the Kennecott facility. Fugitive dust emissions
from tailings piles and ponds at the facility are not specifically regulated but are covered by the general fugitive
dust control requirements for tailings ponds and piles in Utah. Management practices that may be required
for dust control include watering and/or chemical stabilization, synthetic or vegetative covers, wind breaks, and
restrictions on the speed of vehicles in and around tailings operations.
Under the provisions of Title 26, Chapter 11 of the Act, a Utah Pollutant Discharge Elimination
System Permit has been issued to the Magcorp magnesium facility that requires the facility to have no
discharge to surface waters. The permit also requires the facility to monitor pH on a quarterly basis in a test
well adjacent to the impoundment and in standing water between the impoundment dikes and the Great Salt
Lake. Monitoring results that indicate pH values outside of the range of 6.5 to 9.0 must be reported to the
State and EPA within seven days. Based on review of the monitoring data, Magcorp may be required to
develop and implement a plan to eliminate seepage from the impoundment. Any plans developed require
approval prior to implementation.
The ferrous metal facility in Utah under study for this report is the Geneva facility in Orem, Utah.
It generates iron blast furnace slag and APC dust and sludge and steel open-hearth furnace slag and APC dust
and sludge. The facility recycles its slag by selling it to a recycler that is located on or near the Geneva facility
itself. According to State officials, none of these wastes are regulated under the State's solid waste authority,
and the only permits that exist for the facility are air and water quality permits. The facility is currently
involved in negotiating a new NPDES permit with EPA and has just reached a tentative settlement agreement
with EPA in response to a permit violation. According to the State official, the new permit will include new
bio-monitoring requirements and more stringent ammonia effluent limitations. The permitted discharge is
from a retention basin that collects all run-off from the site. Although State air quality regulations require
general fugitive dust control measures, there was no confirmation by State officials that those measures were
in place at the Geneva facility.
-------
Appendix E
Cost and Economic Impact Assessment
Methodology, Assumptions, and Results
-------
Appendix E-1
RCRA Subtitle C Statutory and
Regulatory Provisions
-------
Appendix E-1
RCRA Subtitle C Statutory and Regulatory Provisions
1. Definition of a RCRA Hazardous Waste CFR § 261.3:
1) The waste is or contains a hazardous waste listed in Subpart D of Pan 261; or
2) The waste exhibits any of the characteristics in Subpart C of Part 261: ignitability, corrosivity,
reactivity, or EP toxicity.
a) May be exempted under 261.4(b) - solid wastes that are not hazardous wastes include:
mining overburden returned to mine site;
fly ash waste, bottom ash waste, and flue gas emission control waste generated
primarily from the combustion of coal or other fossil fuels;
solid wastes from the extraction, benefication and processing of ores and minerals
(including coal), including phosphate rock and overburden from the mining of
uranium ore; and
wastes that fail the test for the characteristic of EP toxicity because chromium is
present or are listed in Subpart D because chromium is present, wastes that do
not fail the test for the characteristic of EP toxicity for any other constituent or
are not listed due to the presence of any other constituent, and wastes that do
not fail the test for any other characteristic if shown by a generator that:
the chromium in the waste is exclusively or nearly exclusively trivalent chromium;
the waste is generated from an industrial process that uses trivalent chromium
exclusively or nearly exclusively and the process does not generate hexavalent
chromium; and
the waste is typically and frequently managed in non-oxidizing environments.
b) May be exempted under § 260.22 - Petition to amend Part 261 to exclude a waste from
a particular facility. A person seeking to exclude a particular waste from the list of
wastes in Subpart D must show that the waste does not exhibit any of the criteria under
which the waste was listed as hazardous. The Administrator can look at constituents
in the waste other than those that the waste was listed for. Even though the waste may
be de-listed, it may still exhibit hazardous characteristics and, thus, be regulated under
Subpart C
2. Hazardous Waste Regulations Generally
If generated by a conditionally exempt small quantity generator (SQG), waste is subject
to provisions under § 261.5. A conditionally exempt SQG is a generator that generates
100 kilograms or less of hazardous waste a month.
If intended to be legitimately and beneficially used, re-used, recycled, or reclaimed and
is a sludge or is a listed hazardous waste (Part 261, Subpart D) or is a mixture
containing a listed waste, it is subject to the following regulations with respect to
transportation and storage:
Notification under RCRA § 3010. All persons generating, transporting, treating,
storing, or disposing hazardous waste must notify EPA.
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E-1 -2 RCRA Subtitle C Regulations
Parts 262 and 263. Part 262 concerns requirements for generators of hazardous
waste. Part 263 concerns standards applicable to transporters of hazardous waste.
Pan 264, Subparts A through E. Part 264 sets forth standards that apply to
owners and operators of treatment, storage, and disposal facilities.
Part 265, Subparts A through E, G through J, and L. Sets forth requirements
that apply to facilities that have not received a permit.
Parts 270 and 124. Parts 270 and 124 set forth permit requirements.
If not intended to be legitimately and beneficially used, re-used, recycled, or reclaimed
then is intended to be discarded and subject to subtitle C regulations:
Part 262 - Generators
Part 263 - Transporters
Parts 264 and 262.34 - Owners/operators of TSD facilities - on-site generators
storing waste less than 90 days for subsequent shipment off-site.
Part 265 - Owners/operators of TSD facilities who qualify for interim status must
apply for a permit.
Part 270 - Owners/operators of TSD facilities who do not qualify for interim
status must apply for a permit.
3. Permit Requirements
A RCRA permit must be obtained by persons who treat, store, or dispose of wastes that:
1) have been removed from the Mining \Vaste Exclusion, and
2) are characteristically hazardous or are listed hazardous wastes.
Notification
Persons who treat, store, or dispose of hazardous waste must file a notification with the
Administrator within 90 days of the final rule that removed the wastes from the Bevill
exemption (by April 23,1990). The notification must state the location and description of the
facility and the identified hazardous wastes handled.
If the person is in a State that has an authorized hazardous waste permitting program,
notification will be required after the State receives authorization or amends its program to
regulate these wastes.
Permit Application Made in Two Parts
a) Part A Permit Application
Timely submission of notification and a Part A application qualifies an existing
facility for interim status. The requirements for interim status facilities are
described in section 4 below.
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Appendix E-1: RCRA Subtitle C Regulations E-1-3
b) Part B Permit Application
The Regional Administrator or the State Director will request a Part B
application; facilities will be notified 6 months before the Part B application is
due. Owners and operators of land disposal facilities must submit Pan B
applications within 12 months of the effective date of the regulations. The
requirements for fully permitted facilities are set out in sections 5 through 15
below.
4. Interim Status
Applicability
The Federal standards for interim status facilities apply to owners and operators (O/Os)
of existing treatment, storage, and disposal facilities:
who have fully complied with the notification requirements and the Part A
permit application requirements until either a permit is issued or until closure
and post-closure responsibilities have been met; or
who have failed to obtain interim status.
The standards do not apply to:
persons disposing of hazardous waste by means of ocean disposal under a permit
issued under the Marine Protection, Research, and Sanctuaries Act;
O/Os of a POTW that treats, stores, and disposes of hazardous waste;
persons who treat, store, and dispose of waste regulated by a RCRA authorized
State;
O/Os of a facility managing recyclable materials (261.6 (a) (2) and (3)) (see list
in Part 264 standards, section 5 below);
a generator accumulating hazardous waste on-site for less than 90 days;
O/Os of a totally enclosed treatment facility,
O/Os of an elementary neutralization unit or a wastewater treatment unit (see
definition in Part 264 standards, section 5 below);
a person engaged in treatment or containment activities during immediate
response to a discharge; and
a transporter storing materials in containers meeting applicable requirements.
Permit Application Requirements for Existing Facilities
270.10(e) - O/Os of existing facilities must submit a Part A permit application.
Facilities that submit notification and Pan A of the application are qualified for interim
status.
Part A applications must be submitted within 6 months of the final rule that removed
the wastes from the Bevill exemption (by July 23, 1990).
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E-1-4 RCRA Subtitle C Regulations
Operating Requirements
Requirements for interim status facilities are the same as for fully permitted
facilities under Part 264 (see section 5) except in the following instances:
For tank systems, O/Os must conduct a waste analysis whenever the waste treated
in the tank is substantially different from the waste that was treated in the tank
before. O/Os must perform trial treatment or show that existing treatment meets
applicable requirements;
For surface impoundments, O/Os must conduct a waste analysis whenever the
waste treated in the surface impoundment is substantially different than was
treated before or is being treated by a different process. O/Os must perform trial
tests;
For waste piles, O/Os must analyze a representative sample of incoming waste
unless the wastes are compatible with wastes already being treated; and
For land treatment, O/Os must:
determine the concentrations of substances that exceed the maximum
concentrations contained in Table 1 of Part 261 that cause a waste to
exhibit the EP toxicity characteristic;
if the waste is a listed hazardous waste, determine the concentrations of
substances that caused the waste to be listed; and
if food chain crops are grown, determine the concentrations of arsenic,
cadmium, lead, and mercury, unless the O/O can show that the constit-
uents are not present
5. Fully Permitted Facilities
Applicability
Part 264 standards apply to all O/Os of facilities that treat, store, or dispose of
hazardous waste except as specifically provided.
Standards apply to persons who dispose of hazardous waste through ocean disposal
subject to a permit under the Marine Protection, Research, and Sanctuaries Act only
to the extent that they are included in a RCRA permit by rule.
Standards apply to persons disposing of waste by underground injection subject to a
permit issued under the Underground Injection Control program approved or
promulgated under the Safe Drinking Water Act only to the extent that they are
required by §144.14 of this chapter. (The Pan 264 requirements do not apply to above-
ground treatment or storage of hazardous waste before it is injected underground.)
Standards do not apply to:
persons who treat, store, or dispose of wastes regulated by a State with a State
authorized RCRA hazardous waste program;
O/Os of a facility permitted or licensed by a State to manage municipal or
industrial solid waste if the only hazardous waste generated is exempted under
the small quantity generator provision;
O/Os of a facility managing recyclable materials (261.6 (a) (2) and (3));
Recyclable materials include the following:
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Appendix E-1: RCRA Subtitle C Regulations E-1-5
recyclable materials used in a manner constituting disposal;
recyclable materials from which precious metals are reclaimed;
scrap metal; and
coke and coal tar from the iron and steel industry that contains EPA
hazardous waste K087.
a generator accumulating hazardous waste for less than 90 days;
O/Os of a totally enclosed treatment facility;
O/Os of an elementary neutralization unit (a tank, tank system, container,
transport vehicle, or vessel that is used for neutralizing wastes that are hazardous
only because they exhibit the corrosivity characteristic or they are listed in Part
261, Subpart D only because they exhibit the corrosivity characteristic) or is a
wastewater treatment unit (a tank or tank system device that is pan of a
wastewater treatment facility subject to regulation under the Clean Water Act
and receives, treats, or stores an influent hazardous wastewater; generates and
accumulates a wastewater treatment sludge that is a hazardous waste; or treats
or stores a wastewater treatment sludge that is a hazardous waste);
a person engaged in treatment or containment activities during immediate
response to a discharge; and
a transporter storing materials in containers meeting applicable requirements.
All O/Os that treat, store, or dispose of hazardous waste at a surface impoundment or a
landfill that submit a Pan B permit application after August 8,1985, must provide information
on the potential for the public to be exposed to hazardous waste/constituents through release
from the facility.
O/Os who have already submitted a Pan B application must submit exposure information by
August 8, 1985.
General Information Requirements for Part B Applications
- The following information is required for all hazardous waste management facilities:
264.13(a)(l) - Before an O/O treats, stores, or disposes of a waste he must obtain a
detailed chemical and physical analysis of a sample of the waste. Analysis must contain
all information necessary to treat, store, or dispose of the waste.
264.13(a)(3) - The analysis must be repeated as necessary to assure it is accurate and
up to date.
264.13(b) - O/Os must develop a written waste analysis plan. The plan must contain:
the parameters for each hazardous waste to be analyzed and a rationale for choosing the
parameters; test methods used to test for the parameters; sampling methods used; the
frequency of the review and repetition of the initial waste analysis; for off-site facilities,
the analysis that the generators supply, any additional analysis required for ignitable,
reactive, or incompatible wastes, bulk or containerized liquids, or wastes subject to the
land disposal restrictions; and procedures and schedules for surface impoundments
exempted from land disposal restrictions.
264.14(a) - the O/O must secure his facility to prevent unauthorized entry unless he can
demonstrate physical contact with any of the equipment, waste, etc will not cause injury
and will not cause a violation of this subsection.
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E-1 -6 RCRA Subtitle C Regulations
264.14(b) - If the O/O is required to have security pursuant to § 264.14(a) above, he
must have:
a 24-hour surveillance system or a barrier that will keep people out; and
a means to control entry at all times.
264.15 (a) - O/Os must inspect the facility for malfunctions and deteriorations, operator
error, and discharges. Inspection must be often enough to correct any problems before
they harm human health or the environment.
264.18(a) - New facilities can not be located within 61 meters (200 feet) of a fault that
has had movement of any two sides in Holocene time ("holocene" means the most
recent epoch of the Quarternary period, extending from the end of the Pleistocene to
the present).
264.18(b) - A facility located in a 100-year floodplain must be designed to prevent
washout of any hazardous waste by a 100-year flood. The O/O can avoid the design
requirements if he can demonstrate to the Administrator that: 1) the facility has
procedures that will remove hazardous wastes to a location where the wastes will not
be touched by flood waters; or 2) for existing surface impoundments, waste piles, land
treatment units, landfills, and miscellaneous units, no adverse effects on human health
or the environment will result if washout occurs. Several factors must be considered,
such as the volume and chemical characteristics of waste in the facility, the concentra-
tion of the hazardous constituents that may affect surface water, the impact of the
constituents on users of the water and on water quality standards, and the impact of the
constituents on soil.
264.l8(c) - No non-containerized or bulk liquid hazardous waste can be placed in any
salt dome formation, salt bed formation, underground mine or cave, with the exception
of the Department of Energy \Vaste Isolation Pilot Project in New Mexico.
264.112 - O/Os of hazardous waste management facilities must have a written closure
plan. The closure plan must:
describe how each management facility will be closed;
give an estimate of the types of wastes at the facility, the methods for removing,
transporting, treating, storing, or disposing wastes; and an identification of the
off-site facilities to which the wastes will go;
describe steps to remove and decontaminate all hazardous waste residues,
equipment, containment system components, and soils;
describe all ground-water monitoring, leachate collection, and run-on and run-off
control; and
include a schedule for closure.
264.118 - A copy of the post-closure plan. The plan required for hazardous waste
management facilities must include:
a description of the monitoring and maintenance activities that will be performed
to ensure the integrity of the cap and final cover or other containment system,
and the functioning of the remaining monitoring equipment
264.178 - At closure, all hazardous waste and hazardous waste residue must be removed
from all containment systems. Remaining containers, liners, bases, and soil containing
hazardous constituents must be decontaminated or removed.
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Appendix E-1: RCRA Subtitle C Regulations E-1-7
264.197 - Closure and post-closure care requirements for tank systems: remove or
decontaminate all waste residues, equipment, and tanks. If the O/O can demonstrate
that it is not practicable to remove or decontaminate all contaminated soils, the O/O
must close and perform post-closure care in accordance with the requirements that
apply to a landfill (see §264.310 below).
264.228 - Closure and post-closure care requirements for surface impoundments. The
O/O must:
a) remove or decontaminate all waste residues, contaminated containers, soils, and
equipment; or
b) eliminate free liquids; stabilize remaining wastes to a capacity to support final
cover; and cover the surface impoundment with a final cover that will minimize
long-term liquids migration, require minimal maintenance, promote drainage and
minimize erosion of the cover, accommodate settling or subsidence so that the
cover's integrity is maintained, and have a permeability less than or equal to the
permeability of any bottom liner system or natural soils present.
264.258 - Closure and post-closure care for waste piles. O/Os must:
remove or decontaminate all waste residues, contaminated containers, soils, and
equipment;
if there are hazardous constituents that can not be practicably removed or
treated, the O/O must close the facility as if it were a landfill (see § 264.310
below); and
if a waste pile that does not have a liner designed to minimize migration of
wastes, the O/O must prepare a contingent closure plan in case not all of the
hazardous constituents can be removed.
264.280 - Closure and post-closure care for land treatment facilities. O/Os must:
continue operations that degrade, transform, or immobilize hazardous waste
constituents within the treatment zone;
continue operations to minimize run-off of hazardous constituents;
maintain run-on control system;
maintain run-off management system;
control wind dispersal of hazardous constituents;
continue unsaturated zone monitoring; and
plant vegetative cover on the area being closed.
264.310 - Closure and post-closure care requirements for landfills. O/Os must cover the
landfill with a cover that:
provides long-term minimization of liquid migration through the closed landfill;
requires little maintenance;
accommodates settling and subsidence so that the cover's integrity is maintained;
and
has a permeability of less than or equal to the permeability of any bottom liner
system or natural subsoils present
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E-1 -8 RCRA Subtitle C Regulations
During the post-closure care period the O/O must:
maintain the final cover;
continue leachate collection and removal;
maintain ground-water monitoring; and
prevent run-on and run-off from eroding or damaging the final cover.
264.142 - O/Os must have a detailed written estimate, in current dollars, of the cost of
closing the facility.
264.143 - All O/Os, except those exempted under §264.1, must establish financial
assurance for closure for each facility.
264.144 - O/Os of a disposal surface impoundment, disposal miscellaneous unit, land
treatment unit, landfill unit, or a surface impoundment or waste pile required to prepare
a contingent closure and post-closure plan, must have a detailed written estimate of the
annual cost of closure and post-closure care.
264.145 - All O/Os that must submit a contingent closure and post-closure plan must
establish financial assurance for the post-closure care.
264.147(a) - O/Os of a TSD facility, or a group of facilities, must demonstrate financial
responsibility for bodily injury and property damage to third parties caused by sudden
accidental occurrences arising from the operation of the facility in the amount of at
least SI million per occurrence with an annual aggregate of at least $2 million.
264.147(b) - O/Os of a surface impoundment, landfill, or land treatment facility that is
used to manage hazardous waste, or a group of facilities, must demonstrate financial
responsibility for bodily injury and property damage to third parties caused by non-
sudden accidental occurrences arising from the operation of the facility in the amount
of at least S3 million per occurrence with an annual aggregate of at least $6 million.
O/Os may combine the per-occurrence coverage levels for sudden and non-sudden
occurrences into a single per-occurrence level, and may combine the annual aggregate
coverage levels for sudden and non-sudden occurrences into a single annual aggregate
level
270.14(b)(19) - O/Os must prepare a topographic map showing the distance of 1000 feet
around the facility at a scale of 2.5 centimeters (1 inch) equal to not more than 61.0
meters (200 feet).
270.l4(c) - Additional ground-water protection information. O/Os must:
provide a summary of the ground-water monitoring data obtained during the
interim status period;
identify the uppermost aquifer and aquifers hydraulically interconnected beneath
the facility property. Must include ground-water flow direction and rate, and the
basis for this information;
provide, on the topographic map required under § 270.14(b)(19), a delineation
of the waste management area, the property boundary, the proposed point of
compliance, the proposed location of the ground-water monitoring wells, and the
aquifer information required under § 270.14(c)(2);
provide a description of any plume of contamination that has entered ground
water; and
prepare plans and engineering reports of the proposed ground-water monitoring
system and detection monitoring program.
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Appendix E-1: RCRA Subtitle C Regulations E-1 -9
if hazardous constituents have not been detected in the ground water at the time
of permit application, the O/O must submit information, data, and analyses to
establish a detection monitoring system.
if hazardous constituents have been detected in the ground water at the point of
compliance, the O/O must submit information, data, and analyses to establish a
compliance monitoring system.
if hazardous constituents have been measured in the ground water that exceed
the maximum concentration limits, or if ground-water monitoring at the waste
boundary indicates that hazardous constituents from the facility are present over
background levels, the O/O must submit information, data, and analyses to
establish a corrective action program.
6. SUBPART C - Specific Requirements for Preparedness and Prevention
264.31 - Facilities must be designed to minimize fire, explosion, or release of wastes.
26432 - Facilities must be equipped with:
an internal communications or alarm system;
a device to summon emergency assistance;
portable fire extinguishers; and
water to supply hoses or an automatic sprinkler system.
264.33 - All equipment listed above must be maintained and tested.
7. SUBPART F - Particular Standards for Releases From Solid
Waste Management Units
264.90(b) - An O/O's regulated units are not subject to the requirements under this
section if:
exempt under 264.1; or
the Regional Administrator finds that he operates a unit that:
is an engineered structure that does not receive or contain liquid waste or
waste containing free liquid;
is designed and operated to exclude liquid, precipitation, and other run-on
and run-off;
has both inner and outer layers of containment enclosing the waste;
has a leak detection system built into each containment layer,
the leak detection system will be continually operated and maintained
during the active life of the facility and during closure and post-closure
care; and
the system will not, to a reasonable degree of certainty, allow hazardous
constituents to migrate beyond the outer containment area.
the Regional Administrator finds that the treatment zone of a land treatment
unit does not contain levels of hazardous constituents that are above background
levels by an amount that is statistically significant, and if an unsaturated zone
monitoring program (see § 264.278) has not shown a statistically significant
increase in hazardous constituents below the treatment zone during the operating
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E-1 -10 RCRA Subtitle C Regulations
life of the unit. An exemption under this paragraph can only exempt an O/O
from the requirements of this Subpart during the post-closure care period;
the Regional Administrator determines that there is no potential for migration
of liquid to the uppermost aquifer during the active life of the regulated unit
including the closure period and during the post-closure care period. A certified
geologist or geotechnical engineer must certify this; or
the O/O operates a waste pile that is inside or under a protective cover that
provides protection from precipitation.
264.91 (a) - O/Os must conduct a monitoring and response program (the Regional
Administrator specifies the elements of each applicable program in the facility permit)
as follows:
whenever a hazardous constituent is detected at a statistically significant level at
a compliance point the O/O must institute a compliance monitoring system
pursuant to § 264.99;
whenever the ground-water standard is exceeded by a statistically significant
amount the O/O must complete a corrective action program pursuant to §
264.100;
whenever hazardous constituents from a regulated unit exceed the concentration
limits between the compliance point and the downgradient facility property the
O/O must complete a corrective action program; and
in all other cases, O/Os must institute a detection monitoring program that
monitors waste constituents pursuant to § 264.98.
All ground-water monitoring systems must comply with the requirements in § 264.97 including:
264.97(a) - A ground-water monitoring system must have a sufficient number of wells
at appropriate locations and depths to yield samples from the uppermost aquifer that
represent: 1) the quality of background water that has not been affected by leakage
from a regulated unit; and 2) the quality of ground water passing the point of
compliance.
264.97 (b) - If a facility contains more than one regulated unit, separate ground-water
monitoring systems are not needed for each unit so long as the systems ensure detection
and measurement at the compliance point of hazardous constituents from the regulated
units.
264.97(c) - All monitoring wells must be cased so as to maintain the integrity of the
monitoring bore hole.
Sections 264.98, 264.99, and 264.100 impose specific requirements for detection mojiitoring,
compliance monitoring, and corrective action monitoring systems in addition to the general
requirements specified in § 264.97. These requirements include:
264.98(c) - O/Os must establish and maintain an approved ground-water monitoring
detection system for each chemical parameter and each chemical constituent specified
in the facility permit
264.99(a)-(e) - O/Os who are required to establish a compliance monitoring program
must: monitor the ground water to determine whether the regulated units are in
compliance with the ground-water protection standard specified in § 264.92; install a
ground-water monitoring system at the compliance point; determine whether there is
statistically significant evidence of increased contamination for any chemical parameter
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Appendix E-1: RCRA Subtitle C Regulations E-1 -11
or hazardous constituent specified in the permit; and at least annually, determine the
ground-water flow rate and direction of the uppermost aquifer.
264.100(a) - O/Os must take corrective action to ensure that regulated units are in
compliance with the ground-water protection standard in the facility permit.
264.100(b) - O/Os must institute an approved corrective action program that prevents
hazardous constituents from exceeding their concentration limits by removing the
hazardous waste constituents or treating them in place.
264.100(d) - O/Os must implement an approved ground-water monitoring program to
demonstrate the effectiveness of the corrective action program.
264.101(a) - O/Os seeking a permit for a TSD facility must institute an approved
corrective action program as necessary to protect human health and the environment
for all releases of hazardous waste or constituents from any solid waste management
unit
8. SUBPART G - Closure and Post-Closure
264.111(a) - (c) - O/Os must close the facility in a manner that: 1) minimizes the need
for further maintenance; 2) controls and minimizes post-closure escape of hazardous
waste, run-off, or hazardous waste decomposition products to ground and surface water
and to the atmosphere; and 3) complies with all closure requirements.
264.114 - All contaminated equipment and soils from partial and final closure must be
properly disposed of or decontaminated.
264.117 - Post-closure care must begin after completion of closure and must continue
for 30 years.
9. SUBPART I • Specific Requirements for Use and Management of Containers
264.172 - O/Os must use a container made of or lined with material that will not react
with the hazardous waste to be stored in the container.
264.175(b) - A containment system must have the following:
a base underlying the container that is free of cracks and is impervious so as to
contain leaks and spills until collected;
a base that is sloped or a containment system designed so that liquids from leaks
can be drained and removed;
sufficient capacity to contain 10 percent of the volume of containers or the
volume of the largest container, whichever is greater. Containers that do not
contain free liquids do not have to follow this requirement; and
a method of preventing run-on into the containment system unless the system has
sufficient excess capacity to contain the run-on. Spilled or leaked waste must be
removed from the sump or collection area to prevent overflow.
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E-1 -12 RCRA Subtitle C Regulations
10. SUBPART J - Specific Requirements for Tank Systems
The requirements of this section do not apply to tank systems that do not contain free
liquids and are inside a building with an impermeable floor, a- tank systems, including
sumps, that are pan of a secondary containment system.
264.191 - For each existing tank system that does not have secondary containment, O/Os
must assess the tank system to determine whether it is adequately designed and is
structurally sufficient to store waste. Minimum requirements for assessment are
provided. Requirements include assessment of the design, assessment of the tank,
material used, and components of external shell.
264.192 - O/Os of new tank systems must submit to the Regional Administrator, with
the submittal of Pan B application information, a written assessment, reviewed and
certified by an independent, qualified registered professional engineer, attesting that the
tank system has sufficient structural integrity and is acceptable for storing waste.
264.193 - Secondary containment must be provided for:
all new tank systems and components prior to being put into service;
existing tank systems for which the age cannot be determined, within two years
of January 12, 1987 or when the tank system has reached IS years of age,
whichever comes later,
existing tank systems for which the age cannot be determined, within eight years
of January 12, 1987; if the age of the facility is greater than seven years,
secondary containment must be provided by the time the facility reaches 15 years
of age, or within two years of January 12, 1987, whichever comes later; and
tank systems that store or treat materials that become hazardous wastes after
January 12,1987, within the time intervals required by the preceding paragraphs,
except that the date that a material becomes a hazardous waste must be used in
place of January 12,1987.
264.193(c) - Specifies the following construction requirements for secondary contain-
ment systems that must be met:
constructed of or lined with material that is compatible with the waste that will
go inside the tank;
placed on a foundation or base capable of supporting the system, resistant to
pressure gradients above and below the system, and capable of preventing failure
due to settlement, compression, or uplift;
provided with a leak-detection system designed so that it will detect failures of
the system within 24 hours, or within the earliest practicable time if the O/O can
demonstrate that existing detection systems will not allow detection within 24
hours; and
sloped or otherwise designed or operated to drain and remove liquids that leak
or spill.
264.193(d) - Secondary containment for tanks must include one of more of the
following:
a liner external to the tank;
a vault;
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Appendix E-1: RCRA Subtitle C Regulations E-1 -13
a double-walled tank; or
an equivalent device approved by the Regional Administrator.
264.196 - Requirements for response to leaks: prevent flow or addition of wastes;
remove waste from tank; contain visible release; and provide secondary containment.
11. SUBPART K - Specific Requirements for Surface Impoundments
264.221 (a) - Existing surface impoundments must have a liner that is designed,
constructed, and installed to prevent any migration of wastes to the subsurface soil or
surface and ground water for the active life, including the closure period, of the
impoundment. The liner may allow wastes to migrate into the liner.
264.221(b) - An O/O can be exempted from design requirements if he can show that an
alternative design will prevent migration of wastes.
264.22 l(c) - Each new surface impoundment, each new surface impoundment at an
existing facility, and each replacement of an existing surface impoundment must have
two or more liners and a leachate collection system between the liners.
264.228 - Closure and post-closure care requirements. (See section 5 above.)
264.230 - Incompatible wastes must not be placed in the same surface impoundment
12. SUBPART L - Specific Requirements for Waste Piles
264.250(a) - Regulations apply to O/Os of facilities that treat, store, or dispose of wastes
in waste piles.
264.250(b) - The regulations do not apply to O/Os of waste piles that are closed with
wastes left in place; these waste piles are regulated as landfills. The regulations do not
apply to O/Os of waste piles that are inside or are protected from precipitation provided
that:
liquids or materials containing free liquids are not placed in the pile;
the pile is protected from surface water run-on;
the pile is designed and operated to control dispersal of the waste by wind or
means other than by water; and
the pile will not generate leachate through decomposition.
264.251(a) • A waste pile must have:
a liner that prevents migration of any wastes out of the pile into adjacent
subsurface soil and surface and ground water during the active life of the pile,
including the closure period. The liner may allow wastes to migrate into the
liner itself, and
a leachate collection and removal system above the liner.
264.251(b) • An O/O can be exempted from design requirements if he can show that an
alternative design will prevent migration of wastes.
264.251(c) - O/Os must design, construct, operate, and maintain a run-on control system
capable of preventing flow onto the active portion of the pile during peak discharge
from at least a 25-year storm.
264.251 (d) - O/Os must design, construct, operate, and maintain a run-off management
system to collect and control water volume resulting from a 24-hour, 25-year storm.
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E-1-14 RCRA Subtitle C Regulations
264.251(f) - Any paniculate matter subject to wind dispersal must be covered.
264.257 - Incompatible wastes must not be placed in the same waste pile.
264.258 - Closure and post-closure care requirements. (See section 5 above)
13. SUBPART M - Specific Requirements for Land Treatment
264.271(a) - O/Os who use land treatment must establish a program designed to ensure
that hazardous constituents placed in or on the treatment zone are degraded,
transformed, or immobilized within the treatment zone. The Regional Administrator
will specify in the permit the requirements of the program.
264.27 l(c) - The Regional Administrator will specify the vertical and horizontal
dimensions of the treatment zone. The maximum depth of the treatment zone must be
no more than 1.5 meters (5 feet) from the initial surface soil and more than 1 meter (3
feet) above the seasonal high water table.
264.272(a) - Before applying the waste to the treatment zone, the O/O must demon-
strate, for each waste, that the hazardous constituents in the waste will be completely
degraded, transformed, or immobilized in the treatment zone.
264.272(b) - In performing the demonstration, the O/O can use field tests (must obtain
a treatment and disposal permit), laboratory analysis, available data, or operating data
if an existing facility.
264.273(a) - O/Os must design and operate a facility in accordance with all of the
operating conditions that were used in the demonstration.
264.273(b) - O/Os must design, construct, operate, and maintain the treatment zone to
minimize run-off of hazardous constituents.
264.273(c) - O/Os must design, construct, operate, and maintain a run-on control system
capable of preventing flow onto the active portion of the pile during peak discharge
from at least a 25-year storm.
264.273(d) - O/Os must design, construct, operate, and maintain a run-off management
system to collect and control water volume resulting from a 24-hour, 25-year storm.
264.273(0 - Any paniculate matter subject to wind dispersal must be covered.
264.276(8) - Food-chain crops can be grown on land treatment zones if the O/O can
demonstrate that there is no substantial risk to human health caused by the growth of
the crops on the zone. The demonstration must show that the hazardous constituents
(other than cadmium) will not be transferred to the plants by plant uptake, or will not
occur in concentrations greater than those found in the same plants not grown in
treated soil.
264.276(a) (3) - This demonstration can be made through field tests, greenhouse studies,
available data, or operating data for existing facilities.
264.276(a) (4) - O/Os must obtain a permit for field and greenhouse testing.
264.276(b) - If cadmium is contained in the waste, the following conditions apply:
the pH of the waste and soil mixture must be 6.5 or greater at the time of each
waste application, except for waste containing cadmium at concentrations of 2
mg/kg (dry weight) or less;
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Appendix E-1: RCRA Subtitle C Regulations E-1 -15
the annual application of cadmium from waste must not exceed 0.5 kilograms per
hectare (kg/ha) on land used for tobacco, leafy vegetables, or root crops grown
for human consumption. For other food-chain crops the annual application rate
must not exceed 0.5 kg/ha beginning January 1, 1987;
the cumulative application of cadmium must not exceed 5 kg/ha if the waste and
soil mixture has a pH of less than 6.5; and
if the pH is 6.5 or greater or is maintained at a pH of 6.5 or greater during crop
growth, the cumulative application must not exceed 5 kg/ha if soil cation
exchange capacity (CEC) is less than 5 meq/lOOg; 10 kg/ha if CEC is 5-15
meq/lOOg; and 21 kg/ha if CEC is greater than 15 meq/lOOg.
264.276(b)(2) - If animal feed is the only crop produced, the pH must be 6.5 or greater
at the time of waste application or at the time the crop is planted, whichever is later.
This pH level must be maintained during crop growth.
264.276(b)(2)(iii) - A plan must be prepared showing how the crop will be distributed
to assure that the crop is not consumed by humans.
264.278(a) - O/Os must monitor the soil and soil-pore liquid to determine whether
hazardous constituents have migrated out of the treatment zone.
264.280 - Closure and post-closure care requirements. (See section 5 above)
14. SUBPART N - Specific Requirements for Landfills
264301 (a) - All existing landfills must have a liner system for all portions of the landfill.
The liner system must:
have a liner that prevents any migration of wastes to adjacent subsurface soil and
surface and ground water during the active life of the landfill, including the
closure period. The liner must prevent wastes from passing into the liner itself;
and
have a leachate collection system above the liner.
264.301 (b) - An O/O can be exempted from the design requirements if he can show that
an alternative design prevents migration of wastes.
264.301 (c) - O/Os of a new landfill, a new landfill unit at an existing facility, a
replacement of an existing landfill unit, or a lateral expansion of an existing landfill unit,
must install two or more liners and a leachate collection system above and between the
liners. An O/O can satisfy the requirements of this section by installing a top liner that
prevents migration of any constituent into the liner and a lower liner that prevents
migration of constituents through the liner.
264301 (d) - The double liner requirement will not apply if the O/O can demonstrate
that an alternative design will prevent the migration of any hazardous constituents into
the ground water.
264301 (f) - The landfill must have a run-on control system capable of preventing flow
from at least a 25-year storm onto the active portion of the pile during peak discharge.
264301 (g) - The landfill must have a run-off management system to collect and control
water volume resulting from a 24-hour, 25-year storm.
264301 (h) - Collection and holding facilities for run-on and run-off control systems
must be emptied after storms.
264301 (i) - Any paniculate matter subject to wind dispersal must be covered.
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E-1 -16 RCRA Subtitle C Regulations
264.310 - Closure and post-closure care requirements. (See section 5 above)
264.314(b) - Effective May 8, 1985, bulk or non-containerized liquid hazardous waste
cannot be placed in a landfill.
264 J14(c) - O/Os must perform a test to demonstrate the absence or presence of free
liquids in either bulk or containerized waste.
264.314(e) - Effective November 8,1985, no liquids can be placed in a landfill unless the
Regional Administrator determines that:
the only other alternative is placement in a landfill or an unlined surface
impoundment that contains hazardous waste; and
placement in the landfill will not contaminate ground water.
15. PART 268 - Land Disposal Restrictions
In the final rule for the Third Third land disposal restrictions (LDRs), EPA classified
mineral processing wastes that have been taken out of the Bevill exemption as "newly
identified" wastes. Consequently, BDAT for mineral processing wastes that exhibit
hazardous characteristics (e.g., corrosivity, EP toxicity) will not apply, even if these
wastes are removed from the Mining \Vfcste Exclusion until EPA, by separate
rulemaking, establishes standards for these wastes under §3004(g)(4). Nonetheless,
when newly identified wastes are mixed with other prohibited waste, the newly identified
wastes are subject to existing hazardous waste prohibitions.
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Appendix E-2
Subtitle D-Plus Regulatory
Program Scenario
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Appendix E-2
Subtitle D-Plus Regulatory Program Scenario
This regulatory scenario constitutes one possible approach to a RCRA Subtitle D program for some
or all special wastes from mineral processing that remain within the Mining Waste Exclusion. The approach
described here has been developed solely for analytical purposes by staff of EPA's Special Wastes Branch of
the Office of Solid Waste, and is tailored to address some of the special characteristics of mineral processing
wastes. The reason for inclusion of a Subtitle D scenario in this report is that the Agency is presently
developing a tailored program to address mineral extraction and beneficiation wastes under Subtitle D
(referred to herein as a "D-Plus" program), and would consider applying this program to any of the 20 mineral
processing wastes subject to this study that remain excluded from regulation under RCRA Subtitle C after the
regulatory determination that will follow, and be based upon, this report. The following presents a summary
discussion of the scope and various requirements of the RCRA Subtitle D-Plus program scenario crafted for
use in this Report to Congress.
Applicability and Permits
• Owners/operators of existing units must be in compliance with all applicable provisions of the
rule by the compliance date established by the regulatory authority (i.e., a state with an
approved program or EPA when implementing a state program), which may be no later than
five years following EPA approval of the state mining waste management plan or the federal
implementation of a state plan. Because states will have up to roughly three and one-half
years to develop a mining waste program, the compliance date could fall anywhere from
roughly six to nine years after the promulgation of the federal rule, with eight years following
federal promulgation being a reasonable average.
• New units (i.e., units that begin receiving waste after the compliance date) must be in
compliance upon the initiation of activity.
Compliance entails meeting all technical criteria, having completed all appropriate plans and
assessments (e.g., closure plans), and having all required permits in place. All requirements
are unit-specific.
Waste Characterization
• Owners/operators of all existing and new units must perform, for each unit, a characterization
of the regulated wastes currently or to be managed in the unit, and must update that
characterization at least once every five years. This characterization must include:
A total constituent analysis, using SW-846 or equivalent methods, for arsenic, barium,
cadmium, chromium, lead, mercury, selenium, silver (i.e., TC metals listed at 40 CFR
§ 261.24 Table 1);
A total constituent analysis for radionuclides;
A total constituent analysis for any other parameters identified by the state;
A measure of acid generation potential;
A quantitative assessment of the potential variability in the composition of the regulated
material being managed;
A minimum site characterization (e.g., environmental setting, climate, land/natural
resource setting); and
A description of the characterization protocols used by the owner/operator.
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E-2-2 Appendix E-2: Subtitle D-Plus Regulatory Program Scenario
• Based on these analyses, the owner/operator must identify any and all "parameters of concern"
present in the unit. ("Parameter of concern" is not clearly defined, but most likely will be
defined either explicitly or de facto to include any TC metal present in a measurable
concentra' ^ and any other parameter, such as pH, existing in a manner likely to pose an
environnv. il risk).
Performance Standards
• If one or more parameters of concern are identified for a given unit, the regulatory authority
must establish performance standards for those parameters. In order to establish performance
standards, owners/operators must assess the potential for releases of any of the parameters of
concern from the unit to the environment via ground water, surface water, air, or soils and
surficial materials. The regulatory authority may waive the requirement for establishing surface
water performance standards if the owner/operator demonstrates that the concentration of the
parameter of concern in the regulated unit could not result in a discharge exceeding the
potential performance standard. The regulatory authority may waive the requirement for
establishing air or soils/surficial materials performance standards if the owner/operator
demonstrates that the management practices being performed eliminate the potential for
release to these media.
• The rule establishes methodologies that the regulatory authority must follow in developing
ground water, surface water, air, and soils and surficial materials performance standards. These
methodologies give precedent to established state numeric standards (which must be at least
as stringent as corresponding federal standards), followed by federal numeric standards (i.e.,
MCLs), and finally site-specific risk-based standards. In all cases, if background concentrations
exceed the applicable numeric standard then background becomes the performance standard.
The point of compliance generally is no further than the actual or anticipated unit boundary.
Design and Operating Criteria
Owners/operators of all existing and new units containing one or more parameters of concern
for which performance standards were established must comply with both general and, if
relevant, site-specific design and operating criteria. Actual design and operating criteria
requirements are left largely to the discretion of the regulatory authority.
• The general criteria require that owners/operators ensure "the continued structural stability of
(the unit), and that releases from (the unit) that exceed performance standards and/or
catastrophic failure do not occur." Structural stability must be maintained throughout the
unit's entire active, closure, and post-closure care periods. Owners/operators also must control
human and wildlife access to, and contact with, regulated materials that might pose a human
health or environmental risk. Owners/operators are prohibited from disposing of RCRA
hazardous wastes in the regulated unit. In addition to these mandates and prohibitions, the
general criteria require that owners/operators institute a run-on/run-off control system such
that run-off from the unit will not cause a discharge of pollutants to waters of the U.S. This
run-on/run-off control system also must be placed in a configuration at closure that allows for
restoration of the natural drainage network to the extent practicable.
The general design and operating provisions of the rule also contain unit-specific criteria as
follows:
Existing surface impoundments must maintain sufficient freeboard to prevent
overtopping;
New surface impoundments must be designed to prevent overtopping;
Land application of regulated materials as soil amendments cannot begin until the
owner/operator assesses potential threats to human health and the environment from
potential releases and human contact (i.e., performance standard exceedances),
establishes a plan detailing application rates, and provides for periodic sampling of the
applied materials; and
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Appendix E-2: Subtitle 0-Plus Regulatory Program Scenario E-2-3
Land application of regulated materials as a treatment process can take place only after
the owner/operator completes a soil and surficial material protection plan that
incorporates, as necessary, vadose zone monitoring, periodic measures of the soil
treatment zone depth, a characterization of the uppermost aquifer, test plots to monitor
migration, measurements of soil loadings of pollutants, and periodic reports.
Finally, the general design and operating provisions require that owners/operators submit
information and take steps necessary to ensure the protection of biological resources, including
unit access control, as necessary, and compliance with the Endangered Species Act of 1973.
In addition to these general criteria, units located in certain sensitive areas (as defined by the
rule) must meet location-specific design and operating criteria that are intended to ensure that
releases do not occur in exceedance of performance standards. These criteria are as follows:
FLOODPLAINS (100 year) - Owners/operators must assess the effect of the unit on the
restriction of flow of surface waters, the reduction or temporary loss of water storage
and conductance capacity in the floodplain, and the potential for washout of regulated
materials and resulting contaminant releases. The regulatory authority may require
modifications to existing units, or design plans for new units, as necessary to protect
human health and the environment, based on the owner/operator's assessment.
WETLANDS - Units located in wetlands (as defined by the rule) must comply with all
applicable CWA § 404 provisions and provisions of the Marine Protection, Research
and Sanctuaries Act of 1972. The regulatory authority may require modifications to new
or existing units in order to ensure that performance standards are met.
SEISMIC IMPACT ZONE (i.e., any area where the probability is greater than or equal
to 10 percent that the maximum horizontal acceleration in lithified earth material will
equal or exceed 0.20 g in 50 years) - Owners/operators of existing units may be required
to modify the design and/or to implement operating requirements necessary to ensure
structural stability at the discretion of the regulatory authority. Owners/operators of
new units containing regulated materials with high moisture contents must design,
construct, and operate those units to withstand the maTimum horizontal acceleration
from seismic impacts during operation. Other new units must be designed, constructed,
and operated to ensure structural stability.
UNSTABLE AREAS (e.g., areas with landslide potential or in the path of potential
rock slides or avalanches) - Owners/operators of existing units may be required to
modify the design and/or to implement operating requirements necessary to ensure
structural stability at the discretion of the regulatory authority. Owners/operators of
new units must demonstrate that the proposed design of the unit is adequate to ensure
the stability of all structural components of the unit during operation, closure, and post-
closure care.
FAULT AREAS (i.e., within 61 meters of a fault having had displacement within
Holocene time) - Owners/operators of existing units may be required to modify the
design and/or to implement operating requirements necessary to ensure structural
stability at the discretion of the regulatory authority. Owners/operators of new units
must demonstrate that any movement along the fault and in the adjacent zone of
deformation will not disrupt the contents of the unit or damage the structural stability
of the unit such that applicable performance standards would be exceeded.
KARST TERRANE (i.e., areas where karst topography exists as the result of
dissolution of limestone, dolomite, or other soluble rock) - Owners/operators of new
and existing units must demonstrate that performance standards for ground and surface
water will be met during construction, operation, closure, and post-closure care. At the
discretion of the regulatory authority, owners/operators must undertake a study that:
1) demonstrates, based on hydrogeologic analyses, that the unit(s) is in fact within a
Karst lerrane; 2) characterizes the degree of stability and potential subsidence of the
unit(s) based on the historical changes in regional and local water levels and on the
history and presence of sinkhole development during Holocene time; and 3) demon-
strates, based on engineering analysis; that the unit will not lose its structural stability.
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E-2-4 Appendix E-2: Subtitle D-Plus Regulatory Program Scenario
authority may require the modification of existing units, or the modification of new unit
plans, at its discretion based on the owner/operator's analyses.
PERMAFROST (i.e., areas where water within surface and subsurface material persists
in a frozen or partially frozen state throughout the year) - Owners/operators of existing
units underlain by permafrost may be required to modify the design and/or to implement
operating requirements necessary to ensure structural stability at the discretion of the
regulatory authority. Owners/operators of new units underlain by permafrost must
design, construct, and operate those units to ensure structural stability.
WELLHEAD PROTECTION AREAS (i.e., areas surrounding public water supply
wells) - Owners/operators must conduct a study to determine whether the regulated unit
is in fact within a wellhead protection area, as defined by state or federal criteria. If the
regulated unit is within a wellhead protection area, the regulatory authority may require
the modification of existing units, or the plans for new units, to ensure that contami-
nants for which performance standards were established will not be released.
Monitoring
• Most of the monitoring requirements under this regulatory approach are media-specific,
addressing ground water, surface water, air, and soils and surficial materials. For each of these
media, the owner/operator must perform an assessment of the potential for releases of
parameters of concern from the regulated unit, other than surface water discharges permitted
under § 402 of the Clean Water Act or air emissions authorized under the Clean Air Act. The
regulatory authority may then exempt an owner/operator from monitoring a given medium for
a given parameter if, based on the owner/operator's assessment, the regulatory authority
determines that there will be no release from the unit exceeding that parameter's performance
standard for the medium. For any parameters of concern not exempted from monitoring, the
owner/operator must establish a monitoring system that is capable of characterizing the
background quality of the medium and the extent of contamination, if any, caused by a release.
The media-specific technical monitoring criteria are summarized below.
• GROUND WATER - For any parameters of concern not exempted by the regulatory authority
from ground-water monitoring, the owner/operator must establish a ground-water monitoring
system that is capable of characterizing any release of those parameters of concern from the
unit in violation of respective performance standards. This ground-water monitoring system
must comply with a ground-water monitoring plan that considers the hydrogeologic setting,
number and placement of wells, and the sampling protocol necessary to adequately characterize
background water quality and water quality at the point of compliance. The owner/operator
also must indicate what protocols and statistical methods will be used to determine that an
exceedance of a performance standard has occurred. If the exceedance of a performance
standard is detected and verified, the owner/operator must undertake a corrective action plan
(as described below).
• SURFACE WATER - The emphasis of this regulatory approach is to promote the adoption
of management practices allowing the waiver of monitoring of surface water in lieu of the
establishment of a surface-water monitoring system. Nonetheless, for any parameters of
concern not exempted by the regulatory authority from surface water monitoring, the
owner/operator must establish a surface water monitoring system that is capable of
characterizing any release of those parameters of concern from the unit in violation of the
respective performance standards. This surface water monitoring system must adopt protocols
necessary to ensure the accurate characterization of the receiving surface water quality (i.e.,
background) and the quality of discharges from the unit. Sampling must be undertaken at least
quarterly. If the exceedance of a performance standard is detected and verified, the
owner/operator must undertake a corrective action plan (as described below).
• AIR - The emphasis of this regulatory approach is to promote the adoption of management
practices allowing the waiver of monitoring of air in lieu of the establishment of an air
monitoring system. Nonetheless, for any parameters of concern not exempted by the regulatory
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Appendix E-2: Subtitle D-Plus Regulatory Program Scenario E-2-5
authority from air monitoring, the owner/operator must establish an air monitoring system that
is capable of characterizing any release of those parameters of concern from the unit in
violation of the respective performance standards. This air monitoring system must adopt
protocols necessary to ensure the accurate characterization of the background air quality (as
measured at an upwind point specified by the regulatory authority) and the concentration of
parameters of concern at the point of compliance. The point of compliance for air emissions
under this regulatory approach generally will be the facility boundary. Sampling must be
undertaken at least quarterly. If the exceedance of a performance standard is detected and
verified, the owner/operator must undertake a corrective action plan (as described below).
SOILS AND SURFICIAL MATERIALS - The emphasis of this regulatory approach is to
promote the adoption of management practices allowing the waiver of monitoring of soils and
surficial materials in lieu of the establishment of a soils/surficial materials monitoring system.
Nonetheless, for any parameters of concern not exempted by the regulatory authority from
soils/surficial materials monitoring, the owner/operator must establish a soils/surficial materials
monitoring system that is capable of characterizing any potential release of those parameters
of concern from the unit in violation of respective performance standards. This soils/surficial
materials monitoring program must adopt protocols necessary to ensure the accurate
characterization of the concentrations of parameters of concern in native soils samples and the
concentration of parameters of concern at the point of compliance. Sampling must be
undertaken at least quarterly. If the exceedance of a performance standard is detected and
verified, the owner/operator must undertake a corrective action plan (as described below).
• In addition to these media-specific monitoring criteria, owners/operators must comply with
provisions for the verification of design and operating criteria. The regulatory authority must
specify protocols for the inspection of units by qualified professionals in order to ensure
continued compliance with all applicable design and operating criteria during operational,
closure, and post-closure care periods. If the regulatory authority determines and verifies that
one or more of the applicable design and operating criteria have been violated, the
owner/operator must undertake a corrective action plan.
Corrective Action
• If, based on the results of the monitoring activities required above, the regulatory authority
determines that one or more performance standards have been exceeded at a regulated unit,
the owner/operator must undertake corrective action. The owner/operator's corrective action
activities must follow an approved corrective action plan that 1) is protective of human health
and the environment, 2) proposes a remedy that controls the source(s) of release and ensures
compliance with the performance standard(s), and 3) proposes a schedule for initiating and
completing corrective action. This corrective action plan must be completed within one year
of the determination of exceedance.
If, based on the results of the verification requirements for design and operating criteria
compliance as described above, any defects in a regulated unit are found, or if the unit is not
in compliance with the design and operating criteria for some other reason (e.g., structural
failure), then the owner/operator must submit a corrective action plan that 1) ensures
protection of human health and the environment, 2) provides a remedy that ensures
compliance with applicable design and operating criteria throughout operation, closure, and
post-closure care, and 3) specifies a schedule for initiating and completing corrective action.
In developing the plan, the owner/operator must consider the extent and potential impacts of
non-compliance; the capability of the selected remedy to achieve compliance; and other
relevant factors specified by the regulatory authority. Once the correction action plan is
1 Unlike the RCRA Subtitle C program, corrective action for solid waste management units other than regulated units would not
be required under this scenario.
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E-2-6 Appendix E-2: Subtitle D-Plus Regulatory Program Scenario
approved oy me regulatory authority, the owner/operator must complete corrective action
according to the plan.
Closure/Post-Closure Cere
• The purpose of closure and post-closure care is to ensure the continued structural stability of
the unit and integrity of systems designed to ensure compliance with all performance standards
and design and operating criteria. To this end, all units must continue to comply with all
applicable design and operating criteria, monitoring criteria, and corrective action requirements
throughout the closure and post-closure care periods.
• Closure must include a final regulated materials characterization and may entail further the
removal of all regulated materials from the unit, actions to neutralize or immobilize
parameters of concern, or other actions necessary to ensure permanent compliance with
applicable performance standards and design and operating criteria (e.g., structural stability).
If regulated materials remain in the unit, the owner/operator must add a notation to the
property deed indicating the presence of the material, what it consists of and what parameters
of concern are present, and the anticipated post-closure land use for the area.
• An owner/operator must conduct closure in accordance with the closure plan, which must be
completed and approved prior to the receipt or management of regulated materials, for the
unit(s) in question. The closure plan must include a description of the activities necessary to
ensure adequate closure at any point during the life of the unit, addressing continued
compliance with performance standards, continued structural stability, access control, and any
other relevant design and operating criteria. The closure plan also must be certified by a
qualified professional (as defined by the rule) and must be established as part of an enforceable
permit
• Closure is triggered by 24 months of inactivity and must be completed within five years of the
initiation of closure activities.
• Owners/operators must conduct post-closure care for all units in which regulated materials are
present, unless the owner/operator demonstrates that ongoing maintenance and monitoring is
not necessary to ensure continued compliance with all relevant performance standards and
other technical criteria.
• An owner/operator must conduct post-closure care in accordance with the post-closure care
plan, which must be completed and approved prior to the receipt or management of regulated
materials, for the unit(s) in question. The post-closure care plan must include a description
of the activities necessary to ensure continued compliance with all applicable performance
standards and technical criteria, including structural stability, access control, activities necessary
to maintain a final cover, control erosion, or to control fugitive dust. The post-closure care
plan also must be certified by a qualified professional (as defined by the rule) and must be
established as part of an enforceable permit.
• Post-closure care must be initiated immediately following the certification of closure and must
continue for 30 years, unless the regulatory authority modifies the length of the post-closure
care period.
Financial Responsibility
• Financial responsibility must be maintained by all owners/operators of existing and new units
for 1) closure and, if applicable, post-closure care; 2) corrective action for known releases of
parameters of concern in violation of performance standards or for design and operating
criteria violations; and 3) third-party bodily injury and property damage caused by releases of
parameters of concern.
• Financial responsibility for closure and post-closure care must be based on comprehensive cost
estimates, in current dollars, for all planned activities assuming that the work will be performed
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Appendix E-2: Subtitle D-Plus Regulatory Program Scenario E-2-7
by a third party. Costs must be adjusted annually for inflation until closure and post-closure
care is certified complete. These cost estimates must be included as a condition of an
enforceable permit.
Financial responsibility for corrective action must be based on a detailed cost estimate for
performing all necessary activities according to the approved corrective action plan. The
owner/operator must base the initial cost estimate on current dollars and the assumption that
the work will be performed by a third party. The approved corrective action cost estimate
must be included as a condition of an enforceable permit.
Financial responsibility for third-party bodily injury and property damage caused by a release
must be maintained by the owner/operator in an amount of at least $2 million per occurrence
with an annual aggregate of at least $4 million, exclusive of legal defense costs. The
owner/operator must demonstrate this financial responsibility coverage as part of an
enforceable permit prior to the operation of the unit. The regulatory authority may, at its
discretion, release the owner/operator from third-party liability financial responsibility for a
given unit upon receiving certification that, at a minimum, closure of the unit has been
completed.
Financial responsibility in all cases must be maintained continuously until the regulatory
authority formally releases the owner/operator following the completion of corrective action,
closure, or post-closure care, as appropriate. Allowable financial responsibility mechanisms
must ensure timely, adequate, and legally binding coverage and may not be cancelled without
approval of the regulatory authority. Allowable mechanisms may include insurance pools, state
funds, "or other such mechanisms" to demonstrate compliance with the financial responsibility
requirements of the rule.
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Appendix E-3
Description of
Cost Model and Assumptions
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Appendix E-3
Description of Cost Model and Assumptions
This appendix provides supplementary information on the methods, data, and assumptions that were
employed to estimate the costs and impacts of prospective regulatory alternatives for controlling releases from
special mineral processing wastes. The appendix is divided into two sections. The first outlines the legal and
operational requirements of each alternative, and the second describes the development and application of
EPA's cost estimating model.
»
1. Engineering/Operational Implications of Regulatory Scenarios
This section details the way in which prospective regulatory requirements translate into the "on the
ground" waste management strategies that would be employed by affected facility operators. EPA's approach
in performing this analysis was to delineate all of the applicable requirements comprising each regulatory
scenario, then develop plausible waste management sequences, or "trains" for each of the potentially affected
special mineral processing wastes. Plausible management practices or trains are influenced by the physical and
chemical characteristics of the wastes in question, and by waste generation rates (all of which are, by definition,
large), as well as by specific statutory and regulatory requirements.
Management costs associated with each pertinent regulatory scenario are estimated for each facility
by identifying the specific items (and their costs) that are currently employed (in the baseline case) and that
would be required under the regulatory alternatives. EPA utilized data contained in facility responses to the
1989 SWMPF survey to characterize current practices. The Agency then calculated the costs associated with
each practice employed (e.g., design, construction, and operation of an unlined surface impoundment, waste
stabilization, installation and operation of ground water, surface water, and/or air monitoring equipment); the
sum of these costs is the total management cost at a given facility.
This technology- and facility-specific approach has resulted in management cost estimates that vary
widely among facilities, even among those in the same commodity sectors. For example, EPAs cost estimate
for baseline practices accounts for the presence of waste management controls such as run-on and run-off
control systems and ground water monitoring. Facilities that currently employ these controls have higher
current (baseline) waste management costs (all else being equal) than facilities that do not. Consequently,
prospective Subtitle C or other regulation, and its attendant technical requirements (e.g., run-on and run-off
controls, ground water monitoring) have reduced compliance cost implications at such facilities. Because
EPAs cost analysis relies upon individual cost elements rather than unified cost functions, this variability in
current waste management cost and, therefore, the incremental waste management cost associated with
regulatory alternatives, can be accounted for in full.
Baseline Scenario
The baseline, or "No Action", regulatory scenario assumes that existing waste management practices
will remain unchanged. The waste management practices discussed in the sector-specific chapters of this
report comprise the waste management technologies employed under this scenario. In virtually all cases,
assumed current waste management practices are based upon information submitted to EPA in the form of
responses to the 1989 National Survey of Solid Wutes from Mineral Processing Facilities. In the few instances
in which management practice information was missing or incomplete, the Agency assigned one or more
management technologies based upon knowledge of the common practices used by other similar (e.g., same
commodity sector and size of operation) facilities.
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E-3-2 Appendix E-3: Description of Cost Model and Assumptions
The most common current waste management technologies for solid and some sludge materials
include placement in on-site, unlined landfills; waste piles without a cover or a base; gypsum stacks; and
recycling. Wastewaters tend to be managed in on-site, unlined surface impoundments (some in combination
with a gypsum stack); and in a few cases, synthetic- or clay-lined surface impoundments. Some portion of
these wastewater streams is recycled at nearly all facilities.
A few facilities already meet the technical requirements of RCRA Subtitle C and are in fact, fully
permitted Subtitle C Treatment, Storage, and Disposal Facilities (TSDFs). Such facilities are already subject
to many of the requirements that are evaluated in this report (e.g., Subtitle C financial assurance, corrective
action for continuing releases requirements), and hence, would not experience incremental compliance costs
associated with these specific regulatory requirements if the special waste(s) that they generate were to be
removed from the Mining 'Waste Exclusion. EPA has, accordingly, reflected this fact in conducting its cost
and economic impact analysis.
The baseline scenario for the industry sectors covered by this report would occur under a regulatory
determination by EPA that none of the solid wastes that are currently excluded from regulation under
Subtitle C of RCRA by the Bevill Amendment require regulation as hazardous wastes. Even with such a
regulatory determination, however, some changes in waste management practices may be required. The
mineral processing industry, which has historically been exempt from federal hazardous waste management
regulations under RCRA, has recently had this protection removed by a series of EPA rulemakings that were
concluded on January 23,1990 (55 FR 2322). As of the effective date of this notice (July 23,1990 in non-
authorized states), all mineral processing wastes except the 20 specific wastes considered in this report are
subject to regulation as hazardous wastes (i.e., under RCRA Subtitle C) if they exhibit one or more
characteristics of hazardous waste. EPA believes that many of the facilities considered in this report generate
wastes that are newly subject to these requirements. Consequently, existing "baseline" management practices
that are currently applied to special wastes at some of these facilities may change even if these materials are
not removed from the Mining \Vfcste Exclusion.
In addition, several states have imposed or are in the process of imposing new regulatory requirements
on the operators of mineral processing facilities. For example, the State of Florida has issued a policy
directive requiring that all new phosphogypsum stacks or lateral expansions of existing stacks have a clay liner,
the State Department of Environmental Regulation has also indicated that it plans to initiate a formal
rulemaking process for the development of phosphogypsum management regulations.
Full Subtitle C Scenario
The full Subtitle C ("Subtitle C) scenario examined here for the special study wastes is based on the
premise that any of the 20 wastes exhibiting risk in the risk assessment process described above, including any
that exhibit one or more RCRA hazardous characteristics (EP-toxicity, corrosivity, ignitability, or reactivity)
may be regulated under Subtitle C and would then be subject to the technical requirements of 40 CFR
Part 264.
EPA has examined the full array of Subtitle C regulatory requirements, and has identified those that
would be most relevant from the standpoint of managing mineral processing wastes. These regulatory
provisions are summarized in Appendix E-l to this document.1 The Agency then identified and categorized
all requirements having potential cost implications.
Permitting and Administrative Requirements
In this cost impact analysis, EPA has explicitly considered and developed the cost implications of
bringing a facility into the Subtitle C hazardous waste management system for the first time. Because of the
Appendix E-l is not designed to be an exhaustive list of all potentially applicable provisions of EPA's Subtitle C regulations.
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Appendix E-3: Description of Cost Model and Assumptions E-3-3
high volume nature of the wastes considered in this report, the Agency believes that on-site treatment and/or
disposal of these materials will continue to be the predominant means of management employed by facility
operators, irrespective of the regulatory environment that may be imposed. This suggests that if any of the
20 wastes are placed into the Subtitle C system, the facilities that generate them will endeavor to become fully
permitted Subtitle C Treament, Storage, and Disposal Facilities (TSDFs). Accordingly, EPA has, for this cost
analysis, included the costs of developing the relevant permit applications (Part A and B) as well as necessary
supporting studies, in estimating incremental Subtitle C compliance costs. Facilities that are already in the
system (either as permitted TSDFs or as generators of one or more low volume hazardous wastes removed
from the Mining Waste Exclusion in recent rulemakings) are assumed to experience a lesser (25 percent)
expense associated with obtaining a Subtitle C permit modification for a new waste management unit.
Design and Operating Criteria
For this analysis, EPA has developed cost functions that describe the relationship between waste
generation rate (hence, size/capacity of waste management units) and the cost of each component of a given
waste management technology. That is, each element and its associated cost is evaluated individually at each
site; these costs are then summed to yield the total cost of compliance with the relevant design and operating
criteria. In this way, variable economies of scale (e.g., liner costs and ground-water monitoring costs may have
different economies of scale) can be reflected in EPA's cost estimates.
Application of Assumed Waste Management Technologies
Under the Subtitle C scenario, the Agency assumes that facility operators will upgrade current waste
management technologies, rather than adopt a different waste management practice or technology, unless an
alternative practice would be prohibited or less costly. For example, if a waste is currently disposed in a clay-
lined landfill, the waste is assumed to be disposed in a landfill with a double-synthetic liner over a clay liner
to comply with Subtitle C requirements. Technologies not allowed under Subtitle C are replaced with similar
technologies that comply with RCRA minimum technology requirements (e.g., disposal waste piles are
replaced by RCRA landfills), \testes currently sent to off-site disposal are assumed to continue to be managed
off-site, at facilities in compliance with RCRA Subtitle C requirements unless construction and operation of
new units would be less costly. Materials that are identified at some plants as being hazardous wastes may
not, at other plants, be solid wastes due to alternative management practices (e.g., recycling). Internally
recycled "hazardous wastes" (actually secondary materials) are assumed, under the full Subtitle C scenario, to
continue to be recycled without process changes.
Some wastes currently managed using unique methods required special examination to determine the
expected Subtitle C alternative management practice. For example, phosphogypsum and fluorogypsum are
presently slurried with process wastewater (another special mineral processing waste) at their respective
facilities, then piped to gypsum stack complexes (at most, but not all plants). Gypsum stack complexes consist
of a pile containing the gypsum with an adjoining surface impoundment; these complexes serve the dual
purpose of waste disposal and heat transfer (process water cooling). Gypsum slurry is pumped to one of
several smaller impoundments located on top of the gypsum pile (stack), where the solids settle and eventually
dewater. The process water percolates through the stack and is collected in a drainage ditch surrounding the
stack complex. In some cases, the water in the ponds atop the stack is transported to the adjacent cooling
pond directly.
Under Subtitle C, this practice would have to change radically. Waste gypsum would have to be
disposed in a Subtitle C disposal surface impoundment. This would imply dramatic changes in the ways in
which affected facilities maintain their present water balance, and in other operational factors. Although EPA
is not in a position to develop sophisticated engineering analyses of such process changes that might be
induced by Subtitle C regulation, the Agency has attempted to predict the actual operational consequences
of imposing hazardous waste management requirements on these non-traditional waste management
technologies.
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E-3-4 Appendix E-3: Description of Cost Model and Assumptions
Where current practice involves co-management of both poten'ially hazardous and non-hazardous
wastes, EPA assumes that non-hazardous waste management will continue to occur in the existing waste
management unit while the hazardous waste(s) will be managed in accordance with Subtitle C. The same
assumption holds for situations where a potentially hazardous waste is co-managed with a mining waste. For
example, copper calcium sulfate sludge which is currently disposed with mill (beneficiation) tailings would be
segregated and sent to an appropriate Subtitle C management unit, but the mill tailings would continue to be
disposed in the existing tailings pond. Co-management of special mineral processing wastes, non-special
mineral processing wastes, and/or mineral extraction and beneficiation wastes occurs under current practice
in many of the industry sectors evaluated in this report
In general, the assumption that alternative management will involve an upgrade of existing facilities
is the most reasonable prediction of future alternative waste management, given the limited data available.
EPA is aware, however, that firms will make operational adjustments in response to changes in the regulatory
environment in which they operate. In response to minimum technology requirements, facility operators will
seek the lowest-cost waste management practice that complies with the law. In some cases, this will
undoubtedly involve using new and innovative technologies or adapting existing practices to manage wastes
rather than upgrading existing land disposal facilities to comply with Subtitle C. For example, many plants
that currently dispose of wastes will, under RCRA Subtitle C, be provided with financial incentives to reuse
or reclaim those wastes.
Unfortunately, EPA is unable to accurately identify the specific plants at which special waste
management would shift towards recycling or utilization of waste materials or non-traditional waste
management techniques, without highly detailed information concerning facility-specific business management
and development plans. The Agency has, however, indicated which wastes may be good candidates for waste
utilization, reduction, and/or recycling, and provides a limited identification and evaluation of the options
available to affected facilities.
Also, facilities currently treating and storing wastes in impoundments may shift to using tank storage
and treatment They may do so to avoid complying with the minimum technology requirements for hazardous
waste land disposal units, or to take advantage of the RCRA Subtitle C exemption for wastewater treatment
tanks. In general, EPA believes that facilities will employ tank treatment systems rather than or in conjunction
with constructing minimum technology treatment surface impoundments, and has conducted its compliance
cost analysis accordingly. The Agency has performed comparative cost analyses which indicate that tank
treatment in concrete impoundments is the least-cost management alternative for the waste types and within
the waste generation rate ranges that are relevant to this study.
Land Disposal Restrictions
In its evaluation of the likely response of facility operators to prospective Subtitle C regulation, EPA
has considered the likely impact of the Land Disposal Restrictions (LDRs). These regulations were
implemented in three parts, the last of which was promulgated on May 9,1990. LDRs establish treatment
standards (BOAT) for characteristic hazardous wastes, such that any wastes exhibiting a hazardous
characteristic must be treated to a defined level/with a specified technology prior to disposal on the land (e.g.,
in landfills or surface impoundments). In the final rule establishing BDAT for characteristically hazardous
wastes, EPA explicitly declined to establish BDAT for "newly identified* wastes, including those removed from
the Mining V&ste Exclusion in recent rulemakings (54 FR 36592, 55 FR 2322). By implication, any wastes
considered in this report that are removed from the Exclusion would also be newly identified, hence, not
subject to the "Third Third" Land Disposal Restrictions. Consequently, EPA has not factored the costs of
complying with the BDAT provisions contained in this rule into the present analysis, e.g., EP-toxic slags are
not assumed to be ground up and cement-stabilized prior to disposal
Nonetheless, the Agency has attempted to reflect the intent of the Land Disposal Restrictions
program in defining acceptable Subtitle C management practices for the wastes considered in this report. In
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Appendix E-3: Description of Cost Model and Assumptions E-3-5
some cases, EPA has employed best professional judgment to specify additional steps in the treatment trains
that have been applied to individual wastes; these additional steps often parallel or are identical to the BOAT
specified in the recent final rule. EPA believes that in this way, compliance cost estimates that more closely
parallel real-world permit conditions have resulted. For example, several of the wastewater streams considered
in this report are well known to exhibit pH values less than two. Consequently, they are currently (absent the
Mining Waste Exclusion) prohibited from disposal on the land (e.g., in surface impoundments) unless they
have been subjected to treatment using BOAT EPA has assumed in its cost analysis that these wastes will
undergo pH adjustment in tanks prior to extended storage in impoundments. Similarly, EP toxic wastewater
treatment sludges are assumed to be cement-stabilized prior to Subtitle C landfill disposal.
Corrective Action
Based upon the results of the risk assessment and damage case collection activities described in the
foregoing chapters, EPA believes that some of the wastes that have accumulated at mineral processing sites
may release contaminants to the environment, and therefore, require corrective action. Accurately estimating
the nature and extent of and the appropriate response to existing releases at the mineral processing facilities
considered in this study would, however, be an extremely difficult and complex undertaking. Consequently,
the Agency has not included an explicit analysis of potential corrective action costs in this report. EPA
recognizes that the prospective regulatory compliance costs provided in this document may, therefore, be
underestimates.
It is important to understand, however, that only facilities that are not already subject to corrective
action and generate a waste that exhibits one or more characteristics of hazardous waste that is removed from
the Exclusion would experience corrective action costs that are relevant to this report. The Agency has
determined which of the facilities considered in this document might enter the Subtitle C system for the first
time as a consequence of the upcoming Regulatory Determination, and hence, be newly subject to corrective
action requirements. These facilities are limited to those that (1) are not already Subtitle C TSDFs, and (2)
do not generate a low volume, hazardous waste that was removed from the Mining \Vfeste Exclusion by either
the 9/1/89 or 1/23/90 final rules. EPA has determined that the number of such facilities is small, and that most
are within one commodity sector (phosphoric acid). Therefore, the Agency does not believe that omitting a
quantitative analysis of corrective action costs materially affects the findings and recommendations presented
in this report
Closure and Post-Closure Care
Subtitle C regulations require facility operators to conduct prescribed closure and post-closure care
activities. Closure for land disposal units involves capping with clay and a synthetic membrane liner,
installation of a leachate collection and removal system, and a revegetated soil or rock cap. For this analysis,
EPA has calculated the cost of closing waste management units at the expected conclusion of their operating
life, and of the maintenance, monitoring, and contaminant release control systems required under current
Subtitle C regulations. Because these activities (and their costs) will not occur until well into the future,
closure and post-closure care costs have been discounted to present value, then added to the other cost
components (capital, operation and maintenance costs) to arrive at a total waste management cost for a given
unit. Additional detail on EPA's cost estimating methods is presented below.
Financial Responsibility
Facility operators in the Subtitle C system are required to provide evidence of their ability to bear
the costs associated with closure and post-closure care requirements, and with potential third-party liability.
Moreover, in actual practice, facility operators may be required to provide assurance of their ability to
respond to both sudden and non-sudden contaminant releases from their units (corrective action), though
EPAs final rule addressing financial assurance for corrective action has not yet been promulgated. For this
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E-3-6 Appendix E-3: Description of Cost Model and Assumptions
analysis, EPA has factored in a cost to account for financial responsibility concerns for all facilities potentially
subject to Subtitle C regulation. This cost varies among facilities, depending upon whether the firm owning
the facility (or corporate parent) is able to pass the "Financial Test." Firms with adequate financial resources
to pass this test experience a much lower effective cost for providing financial assurance than other firms.
Subtitle C-Minus Scenario
To assess the potential costs and impacts of less stringent regulation, EPA has evaluated an
intermediate Subtitle C scenario ("Subtitle C-Minus") that assumes that EPA exercises all of the regulatory
flexibility provided by Section 3004(x) of RCRA Section 3004(x) does not give EPA authority to waive
Subtitle C authority based on cost alone. Rather, this provision allows EPA to provide some regulatory
flexibility to mitigate the economic impacts of Subtitle C regulation on the minerals industry provided that
adequate protection of human health and the environment is ensured. This flexibility allows EPA to modify
the relevant provisions to take into account the special characteristics of mining and mineral processing wastes,
practical difficulties in implementing the specific RCRA Subtitle C requirements, and site-specific
characteristics.
As discussed in Chapter 2, this scenario uses the same assumptions as the full Subtitle C regulatory
scenario, with three notable exceptions:
• The prohibition on placing liquids in Subtitle C landfills does not apply;
• Land Disposal Restrictions do not apply, and
• On-site waste management practices, for special mineral processing wastes meet only
pre-HSWA Subtitle C technological requirements, rather than the minimum technology
required under 3004(o) and 3005(j) of the amended RCRA.
Under the Subtitle C-minus scenario, therefore, EPA assumes that facilities continue to replace or
expand disposal units without (generally) installing double liners and leachate collection systems, to dispose
materials in landfills in slurry form, and to continue to manage wastes without applying BDAT prior to land
disposal.
For purposes of estimating the costs of this regulatory alternative in this Report to Congress, EPA
has identified what it tentatively believes would be the absolute minimum allowable extent of regulation under
Subtitle C (i.e., the marimum allowable application of regulatory flexibility). As discussed in Chapters 1 and 2,
however, EPA is in no way suggesting or implying that the model used for costing purposes in preparing this
report represents what the Agency could legally or would determine is an appropriate application of RCRA
§3004(x). EPA has solicited comments on whether this model reasonably reflects allowable practices under
§3004(x). The Agency has applied regulatory flexibility under this scenario on a site-specific basis, taking into
consideration not only existing waste management practices, but also the environmental settings (risk
potential) of the individual facilities. Consequently, the requirements that apply to a facility in an
environmentally sensitive area are more stringent under this scenario than they are for a facility located in an
area with lower risk potential.
To establish the design and operating criteria that would apply to facilities under the Subtitle C-Minus
scenario, EPA evaluated each potentially affected plant in terms of the vulnerability of the environmental
media found at the site, focusing on ground water resources. Each facility was placed into a category (low,
moderate, or high risk potential) based upon an evaluation of intrinsic site characteristics (e.g., depth to
ground water, net recharge, soil composition), damage case findings, and risk analyses (quantitative modeling
results) that was conducted for this report The site-specific results of this effort are presented in
Exhibit E-3-1. These categories determined the specific design and operating standards that were required for
the facilities and, in fact, whether certain currently used management technologies (disposal waste piles) were
even allowed under the Subtitle C-Minus scenario. These design and operating criteria are presented by risk
potential category and management technology in Exhibit E-3-1
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Appendix E-3: Description of Cost Model and Assumptions E-3-7
Exhibit E-3-1
Ground-Water Contamination Potential of
Sites Modeled in the Cost/Economic Impact Analysis
Sector/Site
Ground-Water
Contamination Potential
Rational*
PB/ASARCO/E. Helena, MT
Moderate
PB/ASARCO/Glover, MO
PB/ASARCO/Omaha, NE
PB/Doe Run/Boee, MO
PB/Ooe Run/Here., MO
High
Low
Moderate
Low
Observed contamination potentially attributable to slag
pile, although there is also upgradient contamination
and contamination downgradient may be due to former
practice of sprinkling the pile for dust suppression;
modeling also predicts slight contamination
Observed contamination that is likely attributable to
slag pile; modeling also predicts contamination; karst
terrane may facilitate contaminant migration
No observed contamination; modeling predicts no
contamination in 200 years; very shallow ground water
(2 m), but low net recharge (5 cm/yr) and impermeable
uneaturated zone (primarily silt and clay)
Observed contamination, although may be due to on-
srte impoundments; modeling predicts no con-
tamination; low recharge (5 cm/yr) and large depth to
ground water (45 m), but potential for karst terrane may
facilitate contaminant migration
No observed contamination; modeling predicts no
contamination; ground water moderately shallow (8 m),
but very low recharge (2 cm/yr) and impermeable
unsaturated zone (silt and clay)
CU/ASARCO/Hayden, AZ
CU/Phelps/Playas, NM
CU/Kennecott/Garfield, UT
Low
Low
Low
Modeling predicts no contamination; ground water
moderately shallow (6 m), but very low net recharge (1
to 2.5 cm/yr)
Although ground water shallow (4 m), essentially zero
recharge
Ground water moderately shallow (8 m), but recharge
very low (<1 cm/yr) and impermeable unsaturated zone
(primarily silt and clay); modeling predicts no con-
tamination in 200 years
MG/Magcorp/Rowley, UT
Low
Impoundment designed to have wastewater infiltrate
into ground as a way to reduce volume; ground water
shallow (5 m); subsurface permeable (primarily sand);
State tracking seepage and indicates that it poses a low
risk; low potential for exposure because shallow ground
water is saline (connected with Great Salt Lake)
ZN/ZCA/Monaca. PA
Low
Although high recharge (25 cm/yr), ground water is
deep (24 m); on-efte monitoring has not identified any
contamination; modeling predicts no contamination in
200 years
HA/Allied/Geismar, LA
Moderate
Standing quantity of process wastewater provides a
hydraulic head to drive contaminants to shallow (3 m)
ground water, and contamination seeps observed
around the clearwell pond; however, shallow aquifer
appears to discharge into river without use, and upper-
most useable aquifer is deep (55 m)
FE/LTV7E. Cleveland. OH
Moderate/Low
Ground water deep (23 m); recharge moderate (15
cm/yr); unsaturated zone moderately permeable (loamy
sand)
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E-3-8 Appendix E-3: Description of Cost Model and Assumptions
Exhibit E-3-1 (cont'd)
Ground-Water Contamination Potential of
Sites Modeled in the Cost/Economic Impact Analysis
Sector/Site
Ground-Water
Contamination Potential
Rationale
FE/Bethlehem/Sparrows Pt, MD
Moderate
FE/Sharon/Farrell, PA
FE/USS/Fairless Hills, PA
FE/USS/Lorain, OH
Moderate
High
Moderate
Ground water very shallow (2.5 m), recharge high (28
cm/yr), and unsaturated zone moderately permeable
(loamy sand); however, low potential for exposure
because shallow ground water brackish (not drinkable)
and public water provided from distant supply
Ground water shallow (5 m); recharge moderate (15
cm/yr); permeable unsaturated zone (gravelly sandy
loam)
Ground water shallow (4 m); recharge high (23 cm/yr);
permeable unsaturated zone (sand and gravel)
Ground water moderately deep (15m); recharge low (8
cm/yr); very impermeable unsaturated zone (shale);
APC dust/sludge managed in impoundment, which has
standing liquids that provide a hydraulic head to drive
contaminants into the subsurface
TI/DuPonVNew John., TN
Tl/SCM #1 and *2/Aahtabula, OH
TI/Kerr-McGee/Hamilton, MS
Tl/TimeVHenderaon, NV
High
High
High
High
Waste solids managed in impoundments, which have
standing liquids that provide a hydraulic head to drive
contaminants into the subsurface; ground water
moderately deep (11 m); unsaturated zone imper-
meable (primarily silt and clay)
Waste solids -nanaged In impoundments, which have
standing liquids that provide a hydraulic head to drive
contaminants into the subsurface; ground water mod-
erately shallow (6 m); impermeable subsurface (pri-
marily silt and clay)
Waste solids managed in impoundments, which have
standing liquids that provide a hydraulic head to drive
contaminants into the subsurface; ground water mod-
erately shallow (6 m); permeable subsurface (primarily
sand); modeling predicts contamination
Waste solids managed in impoundments, which have
standing liquids that provide a hydraulic head to drive
contaminants into the subsurface; ground water mod-
erately deep (12 m); permeable subsurface (primarily
sand)
PA/Central/Plant City, FL
PA/CF Chemicals/Bartow, FL
PA/Mobil/Pasadena, TX
High
High
High
PA/Arcadian/Geiamar, LA
Moderate
Observed contamination in sunlcial and upper Floridan
aquifer* attributed to gypsum stack and ponds
Observed contamination in surficial aquifer attributed to
gypsum stack and ponds; State has initiated enfor-
cement action in response
No observed contamination or damage case; ground
water very shallow (2.5 m); impermeable subsurface
(primarily clay); standing quantity of process
wastewater provides a hydraulic head to drive con-
taminants into subsurface
Contamination in shallow (3 m) ground water attributed
to gypsum stack and clearwell areas, but contamination
likely to discharge directly into nearby river and usable
aquifer deeper (55 m) and more protected
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Appendix E-3: Description of Cost Model and Assumptions E-3-9
Exhibit E-3-1 (cont'd)
Ground-Water Contamination Potential of
Sites Modeled in the Cost/Economic Impact Analysis
Sector/Site
Ground-Water
Contamination Potential
Rationale
PA/Royster/Mulberry, FL
PA/Agrico/Donaldsonville, LA
PA/Conserv/Nichols, FL
PA/Agrico/Mulberry, FL
PA/U.S. Agrichem/Ft Meade, FL
PA/Nu-West/Soda Springs, ID
PA/Seminole/Bartow, FL
PA/Gardinier/Riverview, FL
PA/Nu-South/Pascagoula, MS
PA/Texasgurt/Aurora, NC
High
High
High
High
High
High
High
High
High
High
PA/Ch*vron/Rock Springs, WY
Low
PA/IMC FerUMulbeny, FL
PA/Roy«ter/Palmetto, FL
High
High
Observed contamination in surficial aquifer attributed to
gypsum stack and ponds; State has initiated enfor-
cement action in response
Observed contamination of shallow aquifer attributed to
gypsum stack and ponds
Observed contamination in surficial aquifer attributed to
gypsum stack and ponds; State has initiated enfor-
cement action in response
Observed contamination in surficial aquifer attributed to
gypsum stack and ponds; State has initiated enfor-
cement action in response
Observed contamination in surficial aquifer attributed to
gypsum stack and ponds; State has initiated enfor-
cement action in response
Observed ground-water contamination due to dike
failure and large spill; inconclusive data suggest that
some leakage may be occurring presently
Observed contamination of surficial and deeper usable
aquifers that is potentially attributable to gypsum stacks
and associated ponds
Observed contamination of surficial aquifer that is
potentially attri butable to the gypsum stack and process
wastewater ponds
Although no documented contamination or damage
case, process wastewater provide* a hydraulic head
that may drive contaminants to the subsurface; ground
water very shallow (1.5 m); subsurface permeable
(primarily sand)
Observed contamination in surficial and usable inter-
mediate aquifer attributed to process wastewater ponds;
although dike failure at gypsum stack has resulted in
large spills of wastewater, the gypsum stack is not
cleariy implicated as a source of continuing ground-
water contamination
No documented contamination or damage case;
ground water very deep (122 m); subsurface a fractured
shale that is generally impermeable, although con-
taminants could readily migrate In fractures; process
wastewater provides a hydraulic head that could drive
contaminants to the subsurface, but natural recharge
very low (<1 cm/yr) and teaching from dried gypsum
very unlikely
Observed contamination of surficial and usable Floridan
aquifers attributed in part to the gypsum stack and
Observed contamination in surficial aquifer potentially
attributed to gypsum stack and associated ponds; State
has initiated enforcement actions in response
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E-3-10 Appendix E-3: Description of Cost Model and Assumptions
Exhibit E-3-1 (cont'd)
Ground-Water Contamination Potential of
Sites Modeled in the Cost/Economic Impact Analysis
Sector/Site
Ground-Water
Contamination Potential
Rationale
PA/Agrico/Uncle Sam, LA
High
PA/Fe,rmland/Bartow, FL
PA/J.R. Simplot/Pocatello, ID
High
High
PA/Occidental/White Springs, FL
High
Documented site contamination that may be partly due
to phosphogypsum and process wastewater manage-
ment units; ground water shallow (3 m); subsurface
relatively impermeable (primarily clay and silt); process
wastewater provides a hydraulic head to drive con-
taminants into subsurface; natural recharge that seeps
through dried gypsum very low (2.5 cm/yr)
Observed contamination in surficial aquifer that may be
attributed to phosphogypsum and process wastewater
management units; State has initiated enforcement
action in response
Process waste water provides a hydraulic head that
may drive contaminants to the subsurface; ground
water moderately shallow (9 m); subsurface very
permeable (primarily sand and gravel); natural recharge
available to seep through dried gypsum very low (1
cm/yr)
Process waste water provides a hydraulic head that
may drive contaminants to the subsurface; ground
water moderately deep (14m); karat terrene may allow
contaminant transport in solution cavities; high natural
recharge (30 cm/yr) available to seep through any dried
gypsum
At present, some generators of special mineral processing wastes ship their waste(s) off-site for
disposal. Under the Subtitle C-Minus scenario, as for the other scenarios considered in this analysis, EPA has
assumed that this practice will continue if on-site management is more expensive than off-site disposal.
Candidate Subtitle C wastes managed off-site, however, are assumed to be sent to facilities that comply with
all provisions of Subtitle C, i.e., the facilities that receive such wastes do not receive the flexible management
standards that apply to on-site management under Subtitle C-Minus. All other assumptions made for the full
Subtitle C regulatory scenario with respect to the choice of waste management technologies apply to the
Subtitle C-Minus regulatory scenario as well
Subtitle D-Plus Program Scenario
The third and final regulatory alternative considered by the Agency for this analysis of regulatory costs
and impacts is regulation under one possible approach to a RCRA Subtitle D program tailored to address the
special characteristics of large volume mineral processing wastes. The Agency could consider applying such
a Subtitle D program to any of the 20 mineral processing wastes subject to this study that are permanently
excluded from regulation under RCRA Subtitle C
Substantivety, this approach would be a state-implemented program based on a minimum set of
federal technical criteria and provisions for state program primacy. The technical criteria contained within
the hypothetical Subtitle D-Plus program consist essentially of provisions for the state establishment of media-
specific performance standards for ground water, surface water, air, and soils/surficial materials. It would also
establish technical criteria for a variety of required owner/operator activities, including design and operating
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Appendix E-3: Description of Cost Model and Assumptions E-3-11
Exhibit E-3-2
Design and Operating Criteria, and Other Requirements
Under the Subtitle C- Scenario
Waste Management
Practice
Waste Pile Disposal
Surface Impoundment
Disposal
Surface Impoundment
Storage/Treatment
Landfill Disposal
Gypsum Stack
Disposal
Ground Water Exposure/Risk Potential
Low
Current Uner Configuration
Ground-Water Monitoring
Soa/Rock Cap, Regrade as
Necessary
Current Liner Configuration
Ground-Water Monitoring
Soil/Rock Cap
Current Liner Configuration
Ground-Water Monitoring
Current Liner Configuration
Ground-Water Monitoring
Soil/Rock Cap
Current Lfeier Configuration
QrountfWater Monitoring
Moderate
Not Allowed
Composite Liner (new unit)
Ground-Water Monitoring
Composite Cap/Run-off Collection
Composite Uner (new unit)
Ground-Water Monftoring
Clean Closure
3-fl Thick Clay Liner (new unit)
Ground-Water Monitoring
Composite Cap/Run-off Collection
Ck>mpoeite'Uner/Leacnato
Collection (new un$
GroumMtfator Monitoring
Composite Cap/Runoff Collection
High
Not Allowed
Composite Uner (new unit)
Ground-Water Monitoring
Composite Cap/Run-off
Collection
Composite Uner (new unrt)
Ground-Water Monftoring
Clean Closure
Composite Uner/Leachate
Collection (new unit)
Ground-Water Monitoring
Composite Cap/Run-off
Collection
Double Composite Uner/
leacnat* Dectectlon
{newurdt}
GrouncMryater Monitoring
Composite Cap/Run-off
f~t\ttm*lt*n
IXJIjnUUQfl
criteria, monitoring criteria, corrective action requirements, closure and post-closure care criteria, and financial
responsibility requirements.
In addition, the program would require the periodic characterization of regulated materials and a
number of general and location-specific analytic studies designed to ensure that regulated materials
management and closure activities are adequately protective of human health and the environment. Specific
operating and closure requirements (e.g., the use of liners, placement of caps), however, are left in large pan
to the discretion of the states. Because this would be a Subtitle D program that is similar in many respects
to current state Subtitle D solid and industrial waste regulatory provisions, and because the program would
give considerable flexibility to the states regarding the application of specific waste management and closure
requirements, EPA anticipates that the incremental requirements of the program above baseline conditions
would in many cases be minimal.
Design and Operating Criteria
For this analytical scenario, EPA established a variety of design and operating criteria, including
structural stability requirements, requirements applicable to land application activities and for the protection
of biological resources, and location-specific criteria for units located in Qoodplains, seismic impact zones and
unstable/fault areas, Karst Tenanc, and wellhead protection areas (as defined by states pursuant to Safe
Drinking Water Act requirements). The state also would have the flexibility to establish unit-specific
requirements by rule or guidance. Owner/operators would have to follow management practices specified by
the state for any unit for which media-specific performance standards are established by the state (based on
the regulated materials characterization) in order to ensure compliance with those performance standards.
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E-3-12 Appendix E-3: Description of Cost Model and Assumptions
EPA believes that, aside from analytic studies required as pan of the location-specific criteria and
periodic inspections by third parties for structural stability, many of the requirements that would apply under
the Subtitle D-Plus scenario are in fact currently required under existing state regulatory programs. In order
to estimate the incremental costs of this regulatory alternative's design and operating criteria, therefore, the
Agency used empirical data and best professional judgment to calculate the costs of such analytic studies.
The Agency has applied the Subtitle D-Plus scenario design and operating criteria in much the same
way as it has the analogous requirements of the Subtitle C-Minus scenario, i.e., on a risk-based, site-specific
basis. EPA has used the risk potential categories described above (see Exhibit E-3-1) to establish the
standards that apply to waste management units under the Subtitle D-Plus scenario for each potentially
affected facility. The specific requirements that apply for each category and waste management technology
are presented in Exhibit E-3-3. It is important to note that with the exception of sites in the low" risk
potential category, facilities would be required to manage the special wastes in lined waste management units;
in most instances, this implies construction of new units, rather than continued use of existing units.
Consequently, for many facilities, the difference between the Subtitle C-Minus and Subtitle D-Plus scenarios
is minimal, in terms of the activities (and associated costs) that would be mandated under these two regulatory
alternatives.
Monitoring
Under the Subtitle D-Plus scenario, owner/operators would have to establish ground-water, surface
water, and/or air monitoring systems for any units for which ground-water, surface water, and/or air
performance standards, respectively, are established by the state. Unlike Subtitle C, however, this approach
would provide for demonstrations by the owner/operator that management practices adequately isolate and
contain the waste(s) so that a release of hazardous constituents would not occur. The program would, in fact,
encourage the adoption of such management practices in lieu of the establishment of monitoring systems.
EPA believes that, if this management practices approach were not adopted, then the monitoring requirements
established by the state would essentially equate to monitoring requirements provided for under current
regulation. In order to estimate the incremental monitoring costs of the Subtitle D-Plus approach above
baseline, therefore, EPA calculated for each waste stream the cost of management practices that could be used
to isolate and contain the waste and/or the cost of demonstrating that such management practices would
warrant the waiver of monitoring requirements. The Agency believes, however, that only facilities having a
"low" risk potential would be able to demonstrate isolation/containment and therefore be eligible for a waiver
of the requirements; facilities in the "moderate' and "high" risk potential categories would be required to
conduct monitoring (including ground water monitoring) in all cases
Corrective Action
The corrective action provisions established under the Subtitle D-Plus scenario are essentially the
same requirements made under current Subtitle C regulation. The principal difference between the two
programs is that Subtitle D-Plus corrective action requirements would apply only, to releases from regulated
units and not to all other waste management units within the facility boundary. Therefore, in the event that
the Subtitle D-Plus program described here were to be promulgated, corrective action costs would be the same,
or quite possibly lower, than Subtitle C corrective action costs. In addition and as discussed above, the Agency
does not believe that acccurately estimating corrective action costs for this study is tractable, nor would it be
likely to significantly change the findings or implications of this report. As a result, EPA has not estimated
corrective action costs for the Subtitle D-Plus scenario.
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Appendix E-3: Description of Cost Model and Assumptions E-3-13
Exhibit E-3-3
Design and Operating Criteria, and Other Requirements
Under the Subtitle D-Plus Scenario
Waste Management
Practice
Waste Pite Disposal
Surface Impoundment
Disposal
Surface Impoundment
Storage/Treatment
Landfill Disposal
Gypsum Stack
Disposal
Ground Water Exposure/Risk Potential
Low
Current Liner Configuration
Current Liner Configuration
Current Unvr Configuration
Current Liner Configuration
Current Uner Configuration
Moderate
Concrete Uner (new unit)
Leachate/Run-off Treatment
Ground-Water MonMoring
Composite Liner (new unit)
Ground-Water Monitoring
Composite Cap/Run-off Collection
Ground-Water Monitoring
dean Closure
ML Thick day Uner (new unit)
Ground-Water Monitoring
Composite Cap/Run-off Collection
3-ft Thtek Clay Uner (new unity
Sand Layer/Qeot«xtae
GreuncWVatef Mentoring
High
Concrete Uner (new unit)
Leachate/Run-off Treatment
Ground-Water Monitoring
Composite Cap/Run-off
Coftectfcn
Composite Liner (new unit)
Ground-Water Monitoring
Composite Cap/Run-off
Collection
Composite Uner (new unit)
Ground-Water Monitoring
Clean Ctosure
Composite Uner/Leachate
Collection (new unit)
Ground-Water Monitoring
Composite Cap/Run-off
Collection
Composite Uner {new untfj
Leacnate/Rurxoff Collection
and Treatment
Qfound-Water Monitoring
Closure and Post-Closure Care
i
The closure and post-closure care provisions of EPAs Subtitle D-Plus approach, as with the rest of
the program, would allow considerable flexibility to the states in establishing the specific requirements
applicable to owner/operators. EPA believes that states would, in some cases, require closure and post-closure
care activities that are similar to those established under Subtitle C programs. Cases where this approach
would likely apply include the closure of surface impoundments and tank treatment systems. Such activities
might include the removal of wastes, decontamination of soils and equipment, and/or the installation of rock
caps or soil caps with revegetation. For waste piles and landfills, states would likely require actions designed
to stabilize, isolate, and contain wastes, such as chemical fixation to control wind dispersal, permanent
run-on/run-off controls, and neutralization to immobilize metals. EPA believes that the removal of materials
from large waste piles or landfills, or the retrofitting of liners, would not be required. Post-closure care would
apply to any unit containing special wastes after closure and consist of periodic inspections and the
maintenance of run-on/run-off controls, site-access controls, and other ongoing closure activities for a period
of 30 years.
Data gathered from the 1989 SWMPF Survey suggest that in general, owner/operators are not
currently facing state-imposed closure or post-closure care requirements. The application of the
Subtitle D-Plus program to mineral processing wastes, therefore, would impose incremental costs above the
baseline. EPA believes that these costs would resemble those incurred under the Subtitle C scenario, and
hence has computed them in the same manner, accounting fully for differences in final cover material,
monitoring requirements, etc. In addition, EPA estimated the present value cost of preparing closure and
post-closure care plans based on typical costs for such plans under Subtitle C requirements.
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E-3-14 Appendix E-3: Description of Cost Model and Assumptions
Financial Responsibility
The financial responsibility provisions established by the prospective Subtitle D-Plus program are the
same as the provisions established under Subtitle C including coverage for source control and remediation
of known releases (i.e., correc- e action), coverage for closure and post-closure care, and Environmental
Impairment Liability (EIL) cc age (i.e., for third-party damages;.
2. Cost Model Development
Conceptual Waste Management Practices
The three alternative regulatory scenarios considered in this report are based upon Subtitle C of
RCRA, a "Subtitle C-Minus" alternative based upon RCRA §3004(x), and a site-specific, risk-based
Subtitle D-Plus approach. For each alternative scenario, EPA has considered the appropriate legal
requirements (described in the preceding section), and the physical and chemical characteristics and generation
rates of each waste stream analyzed, as well as the technical feasibility of implementing particular waste
management technologies or treatment trains. The result is a well-defined, and quite limited, set of
management practices that are available to facility operators generating one or more of the special mineral
processing wastes. Not surprisingly, the options under the full Subtitle C scenario are more limited both in
number and in the manner in which they can by employed than the options available under the other
alternative regulatory scenarios. The management options that the Agency believes would be available and
feasible within each of the regulatory alternatives are described in the following paragraphs.
Subtitle C
Because of the physical/chemical nature of the special mineral processing wastes and the strict
technical standards of Subtitle C, EPA has identified only four primary ways of disposing of the special mineral
processing wastes: solids must go to landfill disposal, sludges/slurries generally report to surface impoundment
storage/stabilization/disposal system, slurried solids (e.g., phosphogypsum) go to a disposal impoundment, and
wastewaters are subjected to tank/surface impoundment treatment, then discharged or recycled. Because all
of the wastes of interest are inorganic, other types of technologies (e.g., incineration, solvent recovery) are
unavailable. Wastes can also be recycled or recovered, in addition to being disposed or treated. Under
Subtitle C, permanent disposal of material in waste piles is not permitted, though these units may be used for
storage. All land-based units, whether they are used for storage, treatment, or disposal, must contain
impermeable liners, have leachate collection systems, and meet other technical standards, such as closure
requirements. Hence, units such as gypsum stacks are not allowed under the Subtitle C scenario.
Subtitle C-M/nu*
Section 3004(x) of RCRA allows the EPA Administrator to relax certain Subtitle C requirements for
landfills and surface impoundments, i.e., other types of units are ineligible for modified requirements. Among
the HSWA requirements that may be relaxed are the prohibition on placing liquids in landfills, requirements
specific to interim status surface impoundments, corrective action requirements for continuing releases, the
Land Disposal Restrictions (LDRs), and the minimum technical standards that apply to new land disposal
units (e.g., landfills, surface impoundments).
In EPAs view, only the last two of these provisions have much conceptual significance to the Report
to Congress, because: 1) liquids in landfills is an unimportant issue because of the nature of the wastes in
question (sludges will report to surface impoundment or landfill disposal, depending upon moisture content);
2) the interim status provisions have expired (as of 1988); and 3) as discussed above, most of the facilities of
interest are already subject to Subtitle C corrective action provisions.
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Appendix E-3: Description of Cost Model and Assumptions E-3-15
Relaxation of the minimum technical standards, on the other hand, implies some important changes
to the ways in which special wastes may be managed. For example, units may be lined with clay rather than
two synthetic liners, and may be closed without installing a RCRA Subtitle C cap. As a consequence, waste
management costs would be reduced, though the types of waste management practices that are technically
feasible under this scenario generally parallel those that would be available under the full Subtitle C scenario.
One important exception to this is that gypsum stacks would be allowed under Subtitle C-Minus,
though in significantly altered form. Subtitle C-Minus gypsum stacks that would be located in "moderate" or
"high" risk potential areas would be required to have single and double synthetic liners, respectively, as well
as leachate collection and ground-water monitoring systems. In addition, these units would need to be capped
at unit closure with a composite (clay/synthetic) cap, run-off collection system and soil or rock cap. Tb
accomplish this, the shape of gypsum stacks would have to change dramatically. Rather than the steep sides
that characterize most existing stacks, side slopes on Subtitle C-Minus gypsum stacks could not exceed a slope
of three to one (approximately 18 degrees), so as to enable the operator to emplace and maintain the cap at
closure. As a result, new gypsum stacks that would be constructed under this scenario would require far more
land area for disposal of a given quantity of gypsum than conventional stacks. Because most of the major
capital and operating costs of land disposal are a function of area, this difference implies major impacts on
waste management costs at affected facilities.
As discussed above, the Land Disposal Restrictions program would not immediately apply to any of
the 20 special wastes if they were to be removed from the Mining Waste Exclusion. Nonetheless, EPA did
include an extra step in the full Subtitle C costing scenario to account for a plausible means of achieving the
objectives of the LDRs for sludge materials (cement stabilization). In the Subtitle C-Minus scenario, however,
the assumption that EP toxic sludges would need to be cement-stabilized prior to land disposal has been
relaxed, resulting in a significant decrease in the total cost of managing these wastes, as compared to full
Subtitle C.
Subtitle D-Plus
The conceptual Subtitle D-Plus program for mining and mineral processing wastes is a site-specific,
risk-based approach for controlling environmentally significant releases from waste management units. Under
this scenario, waste streams are evaluated on a facility-specific basis, in much the same way as they are under
the Subtitle C-Minus scenario:
• If the waste does contain constituents of concern for a particular pathway but the facility
is located in a setting with "low" risk potential, the operator may demonstrate that his
management practices (current or prospective) limit releases sufficiently to eliminate any
potential risk. In such cases, the operator may comply with program requirements by
"adding on" to existing waste management controls, rather than by constructing new
waste management units. For example, wastes that contain chromium in sufficient
concentrations to pose risk through entrainment of waste dust and downwind exposure
to humans may be controlled by use of dust suppression techniques without triggering
the full array of Subtitle D-Plus program requirements. Thus, under the Subtitle D-Plus
scenario, wastes that exhibit characteristics of hazardous waste may continue to be
managed as they are currently, though some additional control measures may be
required (e.g., run-on/run-off controls, dust suppression).
• In cases where the risk potential is "moderate" or "high," the other aspects of the
program are applicable. These include design and operating criteria, monitoring,
closure and post-closure care requirements, and financial responsibility provisions, as
described in the previous section. Because most facilities considered in this report are
not in compliance with these criteria, most facilities for which risk potential is moderate
or high would have to construct new units if this scenario were to be applied.
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E-3-16 Appendix E-3: Description of Cost Model and Assumptions
Components of the Cost Model
EPAs cost estimating model has two major components: design modeling and cost estimation. For
any tvpe of waste management practice, it is first necessary to calculate the capacity (physical volume for
disp sal units and throughput for treatment units) that will be required to manage the waste(s) of interest.
Then the model moves to the second component, which involves assembling the various cost elements that
in combination comprise a waste management practice, and estimating the cost associated with each element.
Because different elements are in reality a function of different input variables, and because the elements of
interest vary between facilities and among scenarios, the Agency's modeling approach yields a more realistic
view of both current and alternative waste management costs than simple, aggregated cost modeling functions.
Design Model
For wastes that are assumed to be managed in land-based units (e.g., landfills, surface impoundments),
the first step in evaluating waste management costs is to determine the capacity and dimensions of the waste
management unit. The size of the unit is dependent on four user-supplied (in this case, site-specific) variables:
waste generation rate, the percent of solids contained in the waste (for liquids and sludges), the settled density
of these solids (if applicable), and unit operating life. Based on these factors, the model will calculate the
dimensions of a unit large enough to accomodate the predicted accumulation of waste or treatment residue
over the operating life of the unit (15 years for disposal units). In the case of surge ponds (i.e. storage surface
impoundments, the necessary capacity (throughput) is calculated based upon a retention time of one day, i.e.,
the capacity is one-365th of the annual waste generation rate for a wastewater with low solids content. In the
case of storage waste piles, the necessary capacity (throughput) is calculated based upon a retention time of
one week.
Dimensions are based on the assumption that land-based units are square, and are constructed by
excavating the interior and using the material removed to construct benns along each edge. Benns are built
with a three-to-one slope both inside and outside, and have a flattened top that varies in width with the size
of the unit; small units have a berm wide enough to walk on and visually inspect (six feet), while larger units
have progressively wider benns (up to 40 feet) so as to enable vehicles to traverse the top (moderately large
units) or cranes to be placed on the top of the berm and excavate material from inside the unit (large units).
For this analysis, EPA has made the assumption that all new units are constructed on-site. i.e.,
facilities currently have enough land to construct new units of adequate size. This implies that wastes will not
have to be transported significant distances prior to disposal, and that facilities will not need to purchase
additional land at current market prices (though there is an opportunity cost). The Agency has captured the
opportunity cost by including a nominal land cost in calculating the cost of the unit; the number of acres
required exceeds the area of the unit by approximately 20 percent, to allow for a buffer zone. This approach
and its underlying assumptions are based on review of responses to the National Survey, and personal
observations made during EPA visits to numerous mineral processing facilities.
The design modeling process yields a number of unit dimensions and other data that serve as inputs
to the cost element equations. Some costs are a function of the total area of the unit, while others are directly
related to the interior surface area of the unit, unit perimeter, and/or other variables.
Costing Model
Once the dimensions of the unit have been specified, the cost of each required element is calculated,
based upon one or more of these dimensions. Individual element costs are summed to yield the total cost of
the management practice. The specific elements that are required for a given practice depend upon the type
of unit(s) employed and the requirements of the regulatory scenario being examined. Scenarios contain both
general and unit-specific components, which are discussed in the following paragraphs.
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Appendix E-3: Description of Cost Model and Assumptions E-3-17
General Components. For each regulatory scenario, EPA has made provisions for any cost that
would be required of the facility operator either at the facility level or that applies equally to any type of waste
management unit. Examples of these general cost components include (to a first approximation): permitting,
financial asssurance, and site security.
Unit-Specific Components.
• Landfills-The conceptual landfill that the Agency has developed is a large monofill that
is fully constructed in the first year, receives material continuously throughout its
operating life (does not have individual ceils), and is closed with a cap and cover that
encloses the entire unit upon closure. EPA selected this design because it has the
lowest cost (greatest capacity for a given area, lowest permitting cost, etc.), and because
there is no requirement (even under Subtitle C regulations) for individual cell
construction or annual cell closure.
• Surface Impoundments-Surface impoundment construction closely parallels that of
landfills. Disposal surface impoundments are assumed to fill up and require closure at
the end of the operating life; these units are closed in the same way as landfills (for a
given scenario).
• Waste Piles-These units do not require excavation, but do require liners or bases and
covers under some scenarios. Storage waste piles require at least annual turnover of
inventory and must be clean closed.
• Gypsum Stacks-Gypsum stacks are represented as a waste pile topped with an unlined
surface impoundment. The cost of constructing and operating the stack includes a
component for the gypsum slurry pipeline. Under the Subtitle D-Plus scenario, these
units are assumed to be lined with clay, while under the Subtitle C-Minus scenario,
stacks are lined with one or more synthetic liners, depending upon site-specific risk
potential (gypsum stacks are not allowed under the full Subtitle C scenario).
• lank Treatment-EPA has relied upon previous analytical work in developing costs for
tank treatment of hazardous wastewaters. The Agency believes that these existing
equations are valid within the entire range of waste generation rates considered in this
report, and hence, do not require modification for this analysis.
• Off-Site Disposal/Utilization-EPA has incorporated a simple per-ton cost for disposing
wastes and treatment residues off-site in either Subtitle C or D landfills into the cost
model. Unit costs for off-site disposal of wastes are based upon recent contacts with
commercial landfill operators. The Agency does not have adequate data to ascribe costs
or credits associated with manufacturing and selling waste-related products; conse-
quently, no such costs/credits have been built into the model
Application to Special Mineral Processing Wastes
In this section, EPA describes the way in which specific waste streams have been assigned to
management trainsAechnologies for each scenario of interest, some of the region- and site-specific flexibility
that the Agency has built into the costing model, and the analytical assumptions that have been used in
conducting the cost modeling runs.
Assignment of Waste Streams to Management Trains/Technologies
Waste streams are first identified as candidates for regulation under a particular scenario on the basis
of chemical characteristics and, for the Subtitle D-Plus scenario, on a site-specific evaluation of current waste
management practices. Wastes that exhibit one or more characteristics of hazardous waste are assumed to be
candidates for regulation, at the facilities at which EPA's data indicate that the waste may be hazardous.
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E-3-18 Appendix E-3: Description of Cost Model and Assumptions
Facilities for which waste constituent data are unavailable are generally assumed to pass the criteria that apply
to each scenario, with certain sector-specific exceptions.
Subtitle C
Under the Subtitle C scenario, solid materials (copper, lead, and zinc slags, iron/stee: \PC
dust/sludge) are managed in Subtitle C landfills. Slurried solids (phosphogypsum) are managed in Subtitle C
disposal surface impoundments (disposal surface impoundments must comply with landfill closure
requirements). Sludge and sludge solids (titanium tetrachloride waste solids, calcium sulfate WWT sludge)
are settled in storage/treatment impoundments, cement stabilized, then disposed in Subtitle C landfills.
Wastewaters containing small amounts of suspended/dissolved solids (phosphoric acid, hydrofluoric acid, and
magnesium process wastewaters) are collected in small surge ponds, managed in treatment tanks for pH
adjustment, and then routed to their current points of storage, reuse, or discharge. Sludges from this tank
treatment are assumed to be non-hazardous and are disposed in a Subtitle D monofill.
Subtitle C landfills and surface impoundments are constructed using two liners with leachate
collection systems above and between them, a geosynthetic membrane above the upper leachate collection
system, ground-water monitoring systems along the downgradient edge (half the perimeter) of each unit, and
run-on and run-off controls. EPA's run-on/run-off control equations account for whether a facility is located
in a floodplain, in which case surface water control is more difficult and expensive. At closure, these units
are capped with a composite liner and either a layer of clay covered with topsoil or a layer of sand with a
leachate collection system and a rock cap, depending upon the region in which the facility of interest is located
(as discussed more fully below).
Subtitle C-Minus
Under the Subtitle C-Minus scenario, wastes are generally managed using the same technologies as
under Subtitle C, but the design requirements that apply to the units themselves are far less stringent. Section
3004(x) of RCRA allows for the relaxation of the HSWA minimum technical standards for landfills and surface
impoundments, as discussed above. Accordingly, EPA has assumed that some of the more complex and
expensive requirements would be modified under this scenario. The primary differences involve use of single
clay/synthetic liners (except in the case of gypsum stacks located in high risk areas) rather than the double
synthetic liner/leachate collection system and synthetic/clayAopsoil cap configurations required under full
Subtitle C Most other Subtitle C requirements (e.g., permitting, financial assurance, ground-water
monitoring) apply in full in this scenario. As discussed above, modified gypsum stacks are allowed under the
Subtitle C-Minus scenario. Cement stabilization of sludges is not required; sludge, therefore, is disposed in
a disposal surface impoundment
Subtitle D-Plus
The Subtitle D-Plus scenario allows for more flexibility on the part of the operator than either of the
Subtitle C scenarios. Facility operators may use or adapt existing waste management technologies (e.g.,
disposal waste piles) in more situations than they can under the Subtitle C-Minus scenario. Under this
scenario, EPA has assumed that any facility that manages a waste that contains constituents of concern would
first attempt to institute a constituent control mechanism to reduce or prevent releases (e.g., run-on/run-off
controls, dust suppression). This strategy could be effective if the potential pathway(s) of concern involved
air or surface water, but would insufficient if there is a moderate or high potential threat via ground water at
a given site. In that case, requirements for a containment system (i.e., liner), ground water monitoring, and
the other aspects of the full Subtitle D-PIus program would be triggered.
The sectors and facilities that generate one or more wastes that may exhibit EP tenacity or corrosivity
or have resulted in documented damages are analyzed using the model Facilities generating wastes that do
not contain constituents of concern are subject only to periodic waste testing and waste management structural
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Appendix E-3: Description of Cost Model and Assumptions E-3-19
stability requirements; EPA has computed the more or less fixed, constant, and modest costs associated with
these requirements outside the cost model itself. Cost model input data files contain variables that indicate
the pathway(s) that may be of concern for a given facility; these data are based directly on the descriptive risk
analyses that the Agency developed for the risk assessment portion of this report. If these data indicate that
only air and/or surface water pathways are important (i.e., low ground water risk potential), then the model
calculates the cost of the necessary dust suppression measures nm-on/run-off controls, as well as the waste
testing and structural stability studies that apply to all facilities under this scenario. For facilities at which
potential ground-water contamination is an issue, the model computes the cost of constructing a new landfill,
surface impoundment, or gypsum stack containing a single clay or composite liner, or a treatment tank.
ground-water monitoring (if applicable), closure costs (composite and soil or rock cap for land disposal units),
and financial assurance costs (Note: as discussed above, corrective action costs have not been estimated).
Wastes are assumed to be managed in the same manner as they are currently.
One highly significant difference between this scenario and the other two is that under the
Subtitle O-Plus program, EPA has assumed that wastes can be sold and used off-site without further
processing, e.g., slags could be crushed and sized, then sold for use as road base or construction aggregate.
The Agency's data indicate that this constitutes current practice for some wastes at some facilities (i.e.,
baseline). In these cases, EPA has ascribed current management costs associated with storage, but not for
disposal, and has applied this same assumption for the Subtitle D-Plus scenario, i.e., incremental compliance
costs for facilities that sell all of their special waste(s) are assumed to be zero under the Subtitle D-Plus
program.
Regional/Site Variability
In evaluating the management strategies that would be applied to the special mineral processing
wastes under various regulatory scenarios, it is important to consider the substantial variability that exists from
site to site with respect to environmental conditions and to the availability of natural materials that may be
needed for waste management unit construction. These regional and state-level variations have been taken
into consideration in building and applying the cost model, and work in two basic ways: one is in determining
the requirements that apply to a given site and the other is in specifying the availability and cost of materials
needed to employ a given waste management technology (these two factors are in some cases related).
Waste management requirements are influenced by factors such as net precipitation (i.e., leachate
generation potential) and proximity to sensitive environments, such as wetlands. Under all three scenarios,
for example, land disposal unit cover requirements are different for facilities in arid areas than they are for
facilities located in other areas; landfills and surface impoundments located in the Southwest (e.g., Arizona)
are assumed to be capped with a synthetic liner/leachate collection and removal system/rock cap rather than
the synthetic liner/clay layer/drainage layer/soil cap required in other areas of the country.
In addition, the techniques and associated costs that are applied to a particular facility are affected
by existing regulatory requirements and activities. Facilities that are already permitted Subtitle C Treatment,
Storage, and Disposal Facilities (TSDFs) experience only a relatively modest (25 percent of new permit cost)
incremental cost associated with opening a new unit rather than the significant permitting costs associated with
entering the Subtitle C system for the first time.
Facility location affects material costs in a very direct way if a given scenario requires the installation
of a new waste management unit. New units, even under the Subtitle D-Plus scenario, require clay liners, and
under the more stringent scenarios, sand layers containing leachate collection systems between liners. In areas
where natural clay and/or sand is scarce, this may involve a significant differential cost EPA has identified
the areas (states) in which these materials are not naturally abundant and has factored the extra cost involved
in obtaining and transporting them to the site into the cost model. The Agency has assumed that there are
no regional cost differentials that apply to man-made materials (e.g., synthetic liner, geosynthetic filter fabric),
or to the cost or availability of off-site disposal capacity (for both hazardous and non-hazardous wastes).
-------
E-3-20 Appendix E-3: Description of Cost Model and Assumptions
Analytical Assumptions
The final step in developing the cost modeling approach is to specify the analytical assumptions that
will be applied. Many such assumptions are required, and may affect the outcome of the analysis in significant
ways. Wherever possible, EPA has attempted to make important assumptions an input to the cost modeling
process, rather than imbed them in the cost modeling computer code. The necessary assumptions and EPA's
selected values for numerical variables are presented in the following series of bullets.
• Operating Life. EPA has assumed that ail new waste management units will be
operated (receive wastes) for a period of 15 years, after which they will be closed/
dismantled. For the baseline scenario, the Agency has calculated the cost of current
waste management, considering specific controls that may be employed at a particular
site (e.g., run-on/run-off controls, ground water monitoring), as well as the expected life
of the unit (units projected to close in the near term are replaced in the baseline
scenario). For analytical purposes, EPA has assumed that facilities will operate for only
the next IS years. It is worthy of note that after one operational cycle, costs associated
with constructing new units will be negligible (in comparison with current costs) at the
significant and positive discount rates that have been used in this analysis.
• Tax Rate. In order to capture the true cost to the affected firms, EPA has conducted
this analysis on an after-tax basis, and has employed a uniform assumption of the
. maximum federal corporate income tax rate (34.5 percent).
• Discount Rate. EPA has used the results of previous work2 to develop weighted
average cost of capital estimates. For this analysis, the Agency has used the overall
estimate for all affected industries. In addition, EPA has employed the assumption that
affected firms would finance new waste management activities with a combination of
debt and equity such that their capital structure remains unchanged, and thus, have the
same weighted average cost of capital after compliance as they did prior to the
imposition of new regulatory requirements.
• Inflation Rate. EPA has conducted this analysis in real terms, i.e., using an inflation
rate of zero. This makes the analysis computationally simpler, provides less opportunity
for errors in calculation and interpretation, and eliminates the need to make an
assumption about a factor that cannot be predicted with any confidence.
• Sunk Capital. The Agency has employed the assumption that all of the costs of capital
construction of waste management units in the baseline case are unavailable to the firm
(i.e., are sunk) as it responds to new regulatory requirements, except if the firm expects
to replace its unit(s) during the time horizon of the analysis. In these cases, EPA has
incorporated the discounted costs of any new units that will be required in the near-
term (as indicated in the SWMPF Survey) into its estimates of current (baseline) waste
management costs.
2ICF Incorporated. 1990. Regulatory Impact Analysis for the Proposed Rulemaking on Corrective Action for Solid Waste
Management Units (Draftl. Prepared for Economic Analysis Staff, Office of Solid Waste, U.S. EPA. June 25.
-------
Appendix E-4
Sources of Market and Financial Data
-------
Appendix E-4
Sources of Market and Financial Data
EPA calculated ratios of estimated compliance costs to value of shipments and value added and the
ratio of annualized incremental capital costs to annual sustaining capital expenditures using available industry
data. As discussed above, the Agency developed separate compliance cost estimates for waste management
under the Subtitle C, C-Minus, and D-Minus scenarios. EPA then divided these facility-level costs by the
appropriate facility or company data to arrive at the three measures of economic impact
In cases where the affected facility produces an intermediate product (e.g., blister copper, pig iron)
EPA has used the market value (if available) or estimated transfer price in establishing the value of shipments,
and has similarly utilized an estimate of value added that reflects production of the intermediate product. This
situation occurs at only a few facilities in a small number of commodity sectors (e.g., the Asarco/Hayden and
Phelps Dodge/Playas copper smelters, Asarco's Omaha (refinery) and East Helena (smelter) lead facilities).
To calculate value of shipments (VOS) in all sectors, EPA derived annual long-term production
estimates for each facility from data supplied by the United States Bureau of Mines, EPA's 1989 SWMPF
Survey, and the SRI Chemical Manufacturers Yearbook.1 An EPA contractor, Charles River Associates
(CRA), supplied estimated long-term (1995) prices for each commodity. EPA converted the estimated price
per pound estimated by CRA to a price per metric ton by multiplying by 2205. Value of shipments is simply
the product of annual production and price.
CRA also provided estimates of value added for each sector in 1995. Value added is defined here
as the difference between the price of the final mineral commodity and the price (market or transfer) of the
mineral input commodity (e.g., ore concentrate, bullion). The Agency recognizes that a true measure of value
added would also include the costs of other purchased process inputs (e.g., fuel, reagents), but has relied upon
this more simple approach because of data limitations. The value added was estimated in terms of cents-per-
pound. EPA converted the cents-per-pound figure into a percentage of value added for each commodity and
applied it to each firm's value of shipments to derive a value added estimate. The Agency assumed that all
firms within a sector would have a similar cost structure and, therefore, the same percentage of value added.
Investment expenditures for each sector were developed by CRA and reflect estimated sustaining
capital costs for average facilities in each affected sector, expressed as annual investment per ton of product.
In the lead sector, investments for Doe Run's Boss, MO plant were assumed to be zero because the plant is
currently on stand-by status. In the titanium tetrachloride sector, EPA applied the percentage of capital
spending to VOS for titanium metals to the Timet plant, while the capital spending to VOS for titanium
dioxide was applied to all other plants in the sector.
1 1987 Minerals Yearbook. U.S. Bureau of Mines, 1988; Mineral Commodity Summaries 1989. U.S. Bureau of Mines, 1989; 1987
Directory of Chemical Producers. SRI International, 1987.
-------
Appendix E-5
Results of Financial Impact Analysis
-------
Appendix E-5: Results of Financial Impact Analysis E-5-1
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E-5-2 Appendix E-5: Results of Financial Impact Analysis
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Appendix E-5: Results of Financial Impact Analysis E-5-3
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E-5-4 Appendix E-5: Results of Financial Impact Analysis
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SUMMARY OF COMPLIANCE COST RATIOS
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E-5-6 Appendix E-5: Results of Financial Impact Analysis
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Appendix E-5: Results of Financial Impact Analysis E-5-7
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171.7*7. 100
IJ07.440.0M
llt.41l.OM
**"*
IO.04l.Mt
21141.611
It.llt.tlt
4I.M7.1M
OI.MO.M4
M.Ml.Mt
I44.M4.M*
7t.IM.MO
ai4.M7.*70
M.MO.M7
ttUTO.OM
KI.I70.MI
4M.4t7.MI
6.240*77
^"^
-iraplinni
"*"*"*
471. MO
704.100
MO.OM
1.0I4.IM
I.4U.4M
I.O24.6M
4.0M.IM
M.MO
t.llt.lM
Mt.MO
I.MO.MO
1.0II.OM
O.OM.OM
1.U1.IM
T^^
r™'nirrl
— .«
OM.OM
J 647.000
170.100
1.M7.M*
1.MI.MI
0.741.000
22.0I2.7M
Ut.MO
M.MO.MO
I.OM.MO
I.MI.OM
I0.404.0M
M.4II.400
1.046.000
AnnudutitW
1 llMllllHIl 1
— i(W^
144.700
Ml.OM
M.MO
4M.MD
Ml.OM
1. OM.OM
1.2*4.000
M.7W
4.12* JM
701.000
OM.OM
I.MI .MO
I.M4.700
464.400
Coup.
MeMcion
-(*^T
20
14
It
27
17
OO
10
00
1 1
00
00
tl
HI
ite
CO-.P,
••stoic tan
(«*IT)
1 1
It
• 2
72
NA
14*
•77
II
421
277
It 7
211
NA
01
Co-.,,
iTr,..»
^mr
OIK
.M
OIM
OIM
0 t«
06«
OMI
00*1
out
0 l«
02«
om
• Ml
,«
°tir
.(^0
06«
OMI
OM
om
OMI
I2«
24«
0 l«
IM
om
OM
OM
07«
1 4«
IT"*"1
""*"*"''*"'
iznr
4MI
II l«
2m
7m
• 4«
I Ml
it m
OM
• Ml
77H
47W
6 ID
7MI
«m
tmr
^"^T*riM<
"z^r
07«
1 7«
OM
1 IM
OMI
I«M
2M
OM
I4»l
1 in
era
OMI
12*
• 7*
m
61
a
T;
m
V1
-------
SUMUARV OF COMPLIANCE COST RATIOS
INCREMENTAL SUBTITLE O PLUS COSTS TO BASELINE
\Mt
EMM OK**
rumu (Unnmm tp»m^ w«»n .
AMM*-tMI>M»mMT
AWM-MOMIMO
AMfM-OwlMNE
OottAM-aoMMO
DM Ik- - HMMlMMMI MO
•BCTOfl TOTAL
MgnMHM
EMtotMM
ftimn ««n«»ytio, ap^iii WMH ...
iiij m-Ho^nUT
1 1 MM
AtrtctMM - Fort MMd* FL
Aptoo CkmlMl - Mutmnr R.
Ajiliio OMmteil - Und« «•• LA
CkM«- *><* *•*>•• WY
•*i«M*f-RMn»*»FL
UoMI MWng - PM^MM TX
Ma-ami* l»dmm«t - P»«»«oa*« MS
Hu-WM - Bad* Spring* O
fto^Mf ~ PfllflMMo FL
8U8-BECTOR TOTAL
»n>lltrf
>"*l*H
I
1
(Unml»|
{iwrdnx
(ltar
au
M7
•07
M7
H7
M7
3.m
•u
•H
002
*ot
MI
002
0*2
0*2
Mi
002
Ml
0*2
VohMol
«rifMM»«m«
23.IM.I70
M.700.000
17.011.000
U.IT7JM
IM.4M.tM
227.IU.37*
M.CM.OM
140.ltl.000
320.070.000
t4C.4M.OM
171.300.000
1M.Mt.OM
4M.4M.MO
210.7*4.000
104.130.000
iK.7M.OM
041.460000
170.002.000
3.122.3M.OM
V^iMaddad
W»«l
10.12*072
11.041.000
II.2M.«II
1. 113.014
M.IM.040
127.301044
M.17».000
11i.IM.200
2M.700.400
4*4.114.000
114.171.400
173.177.100
Mt.UI.2M
1M.Mt.MO
141.364.200
1*7.Mt.(00
5*0.006 000
IM.4U.WW
3.440.140200
«nn
3*11.1*0
1.111.5*1
4.M1.4M
I.M*.Mt
11.243.172
21.7*4,077
1.017.17*
14440274
13.721 in
22.172.M3
23.712.3*0
1.010.312
W.M0.474
*.l4*,tll
C.MI.M*
0.14*. Ill
2* Ml 131
7.330 3M
1M.1K.Mi
InatmtM*
r-i'Tlf HMIIII
olpraduct
<«M1)
44 1
202
IIS
2*1
1*
1*2
432
222
23 »
710
207
1 7
201
it 4
Ml
240
1*3
211
211
CoMlpo
(«MI)
27*
III
IM*
•22
2*
17*
01
4*
4*
133
41
04
4*
• 1
1»
1 1
43
SI
• 0
Co«.p.
••lux*
«Mr
M*M
•dteH
IfMCM)
2*711
• M
12041
• 2«
0«M
• 0*
1 2«
37«
40W
I2MI
1MI
03«
IM
3I«
10*
400
32«
4 111
41*
ToblupM
n l^i^. fc- .11^1 1
(P^OM)
3152*
13*2*
• 13*
1313*
11**
1023*
663*
4417*
411 1*
113*1*
4211*
100*
4147*
4371*
U17*
4417*
3733*
5MI*
177 1*
Annulc^iM
"^^"•r*n
(p.M«|
470*
20**
13**
2O M
13*
1*1*
12*
MI*
724*
22*1*
Ml*
1 •*
«!**
M3*
17m
•70*
U 7«
•41*
M 1*
m
t
o
>
i
X
m
Ul
|
!
-------
SUMMARY OF COMPLIANCE COST RATIOS
INCREMENTAL SUBTITLE D PIUS COSTS TO BASELINE
rmmniHH ttaai
tHmt* annum*. ap*d*i w«4t»
«i>nniM» r.«itii4ii n
A«.to. cmum n - Ou.yniuii.xi LA
A»liu Omit rt - 6»*» iiiy ft
A|i6ii Oi«4k«l - mid* «•¥• tA
*••«•> -a»*Mi LA
OMMM - Hock %Mtn»« WY
CMMMV - Nkfcoto Ft
"' " '•• ' HW.WW.W* FL
MC fMIMrti - Muttwrv Ft
M***4 u*^HH| - riif'Tni TK
fx.Tiu rijji.-.i.ri
m ***** - ftKianan *O
Ti--TiiiTf - AUHM* NC
SUB-fiCCTOA TOTAL
•EC r Oft TOTAL - HWW AND PHWHTf
ti
it
*""»
62400*
6M.M*
4M.M*
630 HI
21 1.0*0
IM.M*
2*I.*M
274.M6
I.7M.M*
**tMt
332.M*
MI.Mt
1M.MO
32».*0*
I3M.MO
12.2M.Mt
6774.M*
W—
*""»
7l.Mi.IM
Il4.7tt.77*
I27MI.C7*
1M.Ml.aM
4o.aa7.att
62.027074
61113602
2t.20l.724
aU.4M.IT*
M.M7.a*4
•0.6*7.3*4
177 Mt M*
72.*41.7M
M.*4*.4*2
IM4M 73*
M 602. 172
I40.64*.3M
2.270.72462*
2.2M.32I.I12
M2
Mi
Mt
Mi
Mi
Mt
Mi
Mt
Mi
M2
Mt
ttt
Mi
Mi
Mi
Mt
Mt
Mi
34C.6M.OOO
MM7*,Mt
a».«7*XM*
64*.4M.*M
l4f.ttt.OM
•71 IMMt
1M.Mt.Mt
1tt.Mi.Mt
KI.3M.OOO
I.IM.Mt.lMO
iW.7M.Mt
IMtMMt
2I*.7*4.MO
•4*4MMO
2KI.47(.OM
17t.0tt.000
444M4MO
2lt.tl2.OOO
Mt.MI.Mt
•.1M.Mt.OM
3.622 Mt.OOO
unt»
112 10* 200
IM 2*6.400
2M.7M400
4*4.614.000
I1I.C7I600
•6*02.600
173.377600
1*3.24*200
I.OMJM.400
I*7M6.*W
14* aft4 2M
1»7 606 MO
MOM* 000
217.12*400
166462.600
4M177MO
IM.2M.MO
tli.C7l.2M
7.2M.6M.OM
3.440.140.200
14.440.274
l*.47*.64*
I3.7».772
22.t72.Ma
• OM.2M
23 7*2 3M
4 674 Ml
• 010.312
7.660630
4* 41 1.0*0
•.IW.I6I
• Ml M*
• 14*161
10M7.M4
7310.3M
It 61t U6
I.M1.M6
37.666606
117.U2.742
IM.III.M2
tonnaaut
6434 4M
II.*7*SOO
1* MI.4M
I4.I7I.M*
6066600
21 OM IM
• 6074W
4401.600
2*46*00
26.6K.OOO
7.634 **0
73M200
6M0.600
12 163 IM
•.OM.400
100*4.000
12311 2M
4M0.200
I7.2M.MO
211 IM.M*
370364.600
"-"*-
«-.«
I1.7M.600
3C.7MMO
2*7*6400
47.IM.4M
16.021 (M
•2M7 MO
17.677.700
11041.100
7.110.300
7t.23l.HO
22.M7.MO
24 013 3M
14.tM.MO
33*11 MO
It. 161.400
13262200
34 366*00
11461*00
676*3.100
*2>.M*.700
1 64*3I*.WX>
Annul* c^tui
-«""
2.0U200
• 477.3M
4.44* Mt
7 041 MO
2.241 4M
• 2MMO
2*22 MO
1*47600
IOM.MO
II. 12*. 100
12*2600
3663.100
2.223. IM
IOM.MO
2.4I4.M6
4.M3.1M
6 IM.3M
2.M7. IM
6*36400
U 70*30O
230 710.000
Coupv
otfauducl
(tV6JO
104
1*6
21 2
17*
22*
24 4
3*2
16 1
10*
141
227
t»»
1*1
126
163
37*
164
161
127
174
667
0 1
01
0 1
0 1
0 1
0 1
0 1
0 1
0 1
• 1
01
• 2
01
0 1
0 1
02
0 1
0 1
0 1
01
02
CudlOM
~~~
t 641
2M4
1244
2741
3644
3 744
6MI
2344
1 Ml
2 141
3441
46W
24M
1 Ml
2341
6 741
2641
2341
1 t>M
2**
• •44
1 741
3344
3*44
3041
1*44
4 141
• M4
2444
1 641
2441
3641
6041
2741
2 I4|
2M4
• 441
1 141
2641
2 144
2MI
II 041
,-«*"-
—
222744
217 141
20(341
24*741
2M*4*
364244
117 74I|
»4244
162344
241 241
360044
1*2644
12(244
147(44
463644
166 S44
14*741
164041;
IM04I
•71 64|
«— >-
— —
11241
33244
32141
30 6«
3*644
67344
20641
14 144
22744
3*041
62244
24344
22044
67 7V
27 744
22144
23041
27 144
146041
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1
a
ST
m
en
2
c
M
P
11
2
—
d
I
u
3
•
«
m
-------
E-5-12 Appendix E-5: R««ulta of Financial Impact Analyst
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