vvEPA
United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(5305W)
EPA530-R-96-053
November 1996
Hazardous Waste Characteristics
Scoping Study
Recycled/Recyclable Printed with Vegetable Based Inks on Recycled Paper (20% Postconsumer)
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TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY ES-1
CHAPTER 1. INTRODUCTION .. .. 1-1
1.1 Purpose and Requirements of the Hazardous Waste Characteristics
Scoping Study 1-1
1.2 Regulatory Background 1-2
1.3 Approach for Studying Potential Gaps in the Hazardous Waste
Characteristics 1-4
Step 1: Characterize Releases from Non-Hazardous Industrial Waste
Management 1-4
Step 2: Categorize Risks Associated with Non-Hazardous Industrial
Waste Management 1-4
Step 3: Review the Existing Characteristics 1-4
Step 4: Identify Gaps Associated with Non-TC Chemicals 1-6
Step 5: Identify Potential Gaps Associated with Certain Natural
Resource Damages and Large-Scale Environmental Problems 1-6
Step 6: Review State Expansions of TC and State Listings 1-7
Step 7: Evaluate the Industries and Waste Management Practices
Associated with Potential Gaps 1-7
Step 8: Assess Regulatory Programs' Coverage of Potential Gaps 1-8
Step 9: Present Integrated Evaluation of Nature and Extent of
Potential Gaps 1-8
1.4 Report Outline 1-8
CHAPTER 2. RELEASES FROM NON-HAZARDOUS INDUSTRIAL WASTE
MANAGEMENT UNITS 2-1
2.1 Methodology 2-1
2.1.1 Criteria For Selecting Releases 2-1
2.1.2 Approach For Identifying Releases 2-3
2.1.2.1 State Industrial D Programs 2-3
2.1.2.2 State Superfund Programs 2-5
2.1.2.3 Federal Superfund Program 2-6
2.1.2.4 Construction and Demolition (C&D) Landfill Report 2-6
2.1.3 Release Profile Preparation 2-7
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TABLE OF CONTENTS (Continued)
2.2 Results 2-8
2.2.1 Number of Cases By State 2-8
2.2.2 Number of Cases By Industry 2-10
2.2.3 Number of Cases By Type of Waste Management Unit 2-11
2.2.4 Type of Media Affected 2-12
2.2.5 Types of Contaminants Released 2-13
2.3 Major Limitations 2-17
CHAPTER 3. POTENTIAL GAPS ASSOCIATED WITH HAZARDOUS WASTE
CHARACTERISTICS DEFINITIONS 3-1
3.1 Types of Risks Addressed by RCRA Hazardous Waste
Characteristics 3-1
3.1.1 Statutory and Regulatory Framework 3-1
3.1.2 Risks Associated with Physical Hazards 3-3
3.1.3 Acute Toxic Hazards to Humans 3-4
3.1.4 Chronic Toxicity Risks to Humans . 3-4
3.1.5 Risks to Non-Human Receptors 3-5
3.1.6 Other Risks Associated with Non-Hazardous Industrial
Waste Management 3-6
3.2 Ignitability Characteristic 3-8
3.2.1 Definition of Ignitability 3-8
3.2.2 Potential Gaps Related to Definition of Ignitability 3-9
3.2.3 Potential Gaps Related to Ignitability Test Methods 3-12
3.3 Corrosivity 3-12
3.3.1 Definition of Corrosivity 3-12
3.3.2 Potential Gaps Related to Definition of Corrosivity 3-13
3.3.3 Potential Gaps Related to Corrosivity Test Methods 3-16
3.4 Reactivity 3-16
3.4.1 Definition of Reactivity 3-16
3.4.2 Potential Gaps Related to Definition of Reactivity 3-17
3.4.3 Potential Gaps Related to Reactivity Test Methods 3-19
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TABLE OF CONTENTS (Continued)
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3.5 Potential Gaps Associated with the Toxicity Characteristic - 3-19
3.5.1 Definition of Toxicity Characteristic 3-19
3.5.2 Changes in Groundwater Pathway Analysis 3-21
3.5.3 Potential Inhalation Pathway Risks Associated with TC
Analytes 3-27
3.5.4 Potential Risks from Surface Water Exposures 3-33
3.5.5 Potential Indirect Pathway Risks from TC Analytes *. 3-35
3.5.6 Potential for Acute Adverse Effects of Exposures to TC
Analytes 3-38
3.5.7 Potential Risks to Ecological Receptors from TC Analytes 3-38
3.6 Potential Gaps Associated with TCLP 3-39
3.6.1 TCLP Background 3-39
3.6.2 Limitations of the TCLP 3-42
CHAPTER 4. POTENTIAL GAPS ASSOCIATED WITH NON-TC CHEMICALS 4-1
4.1 Overview of Methodology 4-1
Step 1: Identify and Classify Known Non-Hazardous Industrial
Waste Constituents 4-1
Step 2: Identify and Screen Possible Non-Hazardous Industrial
Waste Constituents 4-1
Step 3: Apply Hazard-Based Screening Criteria 4-3
Step 4: Review Relevant Multipathway Risk Modeling Results 4-3
Step 5: Identify Potential Acute Hazards 4-3
Step 6: Summarize Findings 4-3
4.2 Identify and Classify Known Constituents of Non-Hazardous
Industrial Wastes , 4-3
4.3 Identify Possible Non-Hazardous Industrial Waste Constituents of
Potential Concern 4-7
4.3.1 Approach to Identifying Potentially Hazardous Chemicals 4-7
4.3.2 Screening Approach 4-9
4.3.3 Toxicity, Fate, and Transport Screening for Possible Non-
Hazardous Industrial Waste Constituents 4-12
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TABLE OF CONTENTS (Continued)
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4.3.4 Release Volume Screening of Possible Non-Hazardous
Industrial Waste Constituents 4-15
4.3.5 Summary of Possible Non-Hazardous Industrial Waste
Constituents 4-20
4.4 Combine and Screen Known and Possible Non-Hazardous Industrial
Waste Constituents 4-20
4.4.1 Combine the Lists 4-20
4.4.2 Screen Combined List Against Single Criteria 4-25
4.4.3 Screen Combined List Against Multiple Parameters 4-33
4.5 Driving Risk Pathways for the Known and Possible Non-Hazardous
Industrial Waste Constituents 4-34
4.6 Potential Acute Hazards Associated With Known and Possible Non-
Hazardous Industrial Waste Constituents 4-35
4.7 Identify Individual Chemicals and Classes of Chemicals Constituting
Potential Gaps 4-40
CHAPTER 5. POTENTIAL GAPS ASSOCIATED WITH NATURAL RESOURCE
DAMAGES AND LARGE-SCALE ENVIRONMENTAL PROBLEMS 5-1
5.1 Damage to Groundwater Resources 5-1
5.2 Damage to Local Air Quality from Odors 5-2
5.3 Large-Scale Environmental Problems 5-4
5.3.1 Air Deposition to the Great Waters 5-4
5.3.2 Airborne Particulates 5-6
5.3.3 Global Climate Change 5-7
5.3.4 Potential Damages from Endocrine Disrupters 5-9
5.3.5 Red Tides 5-13
5.3.6 Stratospheric Ozone Depletion 5-14
5.3.7 Tropospheric Ozone and Photochemical Air Pollution 5-15
5.3.8 Water Pollution 5-15
CHAPTER 6. STATE EXPANSIONS OF THE TOXICITY CHARACTERISTIC AND
LISTINGS 6-1
6.1 State Expanded Toxicity Characteristics 6-1
6.2 State Only Listings 6-2
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TABLE OF CONTENTS (Continued)
6.3 State Restrictions on Exemptions 6-5
6.4 Summary 6"6
CHAPTER 7. SUMMARY OF POTENTIAL GAPS 7-1
7.1 Organization of the Analysis of Potential Gaps 7-1
7.2 Summary of Potential Gaps 7-2
CHAPTER 8. POTENTIAL GAPS AS FUNCTION OF INDUSTRY AND WASTE
MANAGEMENT METHODS 8-1
8.1 Data Sources and Major Limitations 8-1
8.2 Potential Gaps as a Function of Industry/Waste Source 8-3
8.2.1 Non-Hazardous Industrial Waste Generation by Industry 8-3
8.2.2 Industries Responsible for Documented Non-Hazardous
Industrial Waste Releases 8-5
8.2.3 Occurrence of High-Hazard Industrial Waste Constituents by
Industry 8-8
8.2.4 Industries Reporting Releases of TC Analytes or Known or
Possible Non-Hazardous Industrial Waste Constituents 8-18
8.3 Potential Gaps as a Function of Management Practices 8-21
8.3.1 Waste Management Practices by Waste Type and Industry 8-21
8.3.2 Management Practices Seen in the Release Descriptions 8-24
8.3.3 Potential Hazards Associated with Use Constituting Disposal 8-29
8.3.4 Potential Hazards Associated with Other Management
Practices 8-31
CHAPTER 9. POTENTIAL FOR GAPS TO BE ADDRESSED BY EXISTING
REGULATIONS 9-1
9.1 RCRA Programs 9-1
9.1.1 Hazardous Waste Programs 9-1
9.1.2 Subtitle D 9-3
9.2 Medium-Specific Regulations 9-3
9.2.1 Clean Water Act 9-4
9.2.2 Safe Drinking Water Act 9-7
9.2.3 Clean Air Act Amendments 9-10
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TABLE OF CONTENTS (Continued)
9.3 Federal Insecticide, Fungicide, and Rodenticide Act 9-13
9.4 Toxic Substance Control Act 9-15
9.5 Pollution Prevention 9-15
9.6 Occupational Safety and Health Act 9-16
9.7 Hazardous Materials Transportation Act 9-16
9.8 Summary . 9-19
CHAPTER 10. SUMMARY EVALUATION OF NATURE AND EXTENT OF
POTENTIAL GAPS 10-1
10.1 Overview of the Evaluation of Potential Gaps 10-1
10.1.1 Objectives of the Gaps Analysis 10-1
10.1.2 Criteria Used for Evaluating Gaps 10-1
10.2 Findings of the Evaluation 10-3
10.2.1 Potential Gaps Associated with the ICR Characteristics 10-3
10.2.2 Potential Gaps Associated with TC Analytes 10-8
10.2.3 Potential Gaps Associated with Non-TC Waste Constituents 10-14
10.2.4 Potential Gaps Associated With Resource Damage and
Large-Scale Environmental Problems 10-22
10.2.5 Gaps Associated with State TC Expansions and Listings 10-25
10.2.6 Major Data Gaps and Uncertainties 10-26
10.3 Framework for Determining an Appropriate Course of Action 10-27
10.3.1 Step 1: Identify Critical Research Needs and Next
Steps Necessary to Analyze Key Issues and Fill
Major Data Deficiencies , 10-27
10.3.2 Step 2: Identify and Evaluate Options to Address Any
Clearly Identified Gaps 10-27
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LIST OF EXHIBITS
Page
Exhibit 1-1 Scoping Study Approach ............................................ !-5
Exhibit 2-1 Number of Release Descriptions By State ................................ 2-9
Exhibit 2-2 Number of Management Units & Volume of Waste Managed On-Site, by
State (1985) [[[ 2-9
Exhibit 2-3 Number of Case Studies by Industry (SIC) ................................ 2-10
Exhibit 2-4 Number of Case Studies By Waste Management Unit ........................ 2-12
Exhibit 2-5 TC Contaminants Detected in Case Studies ...... . ........................ 2-14
Exhibit 2-6 Contaminants with SMCLs Detected in Case Studies ......................... 2-15
Exhibit 2-7 Other Contaminants Detected in At Least Three Case Studies ................... 2-16
Exhibit 2-8 Most Common Constituents By Industry ................................. 2-18
Exhibit 3-1 Risks Potentially Associated with Non-Hazardous Industrial Waste
Management [[[ 3-7
Exhibit 3-2 Materials Formerly Classified by DOT as Combustible Liquids (which
generally are not RCRA ignitable) ...................................... 3-11
Exhibit 3-3 Other Definitions of Reactivity ........................................ 3-18
Exhibit 3-4 TC Constituents and Regulatory Levels (mg/1) ............................. 3-20
Exhibit 3-5 Comparison of TC Regulatory Concentrations and HWIR-Waste Proposed
Exit/Leech Levels ................................................. 3-25
Exhibit 3-6 Summary of Inhalation Pathway Screening Methods, Input Data, and Models
Used for Bounding Risk Analysis ...................................... 3-29
Exhibit 3-7 Emission Fraction for Air Releases of Volatile TC Analytes .................... 3-30
Exhibit 3-8 Inhalation Pathway Risks for TC Analytes and Their Dependence on Fate and
Transport Properties ....... . ........................................ 3-32
Exhibit 3-9 Major Fate and Transport Parameters for TC Analytes ....... ................. 3-36
Exhibit 3-10 Ratios of TC Leachate Regulatory Levels to Ambient Water Quality Criteria
for Aquatic Life .................................................. 3-40
Exhibit 4-1 "Flow Chart of Procedures Used to Identify Non-TC Chemicals Posing
Potential Gaps in the TC Characteristics ................................. 4-2
Exhibit 4-2 Known Non-Hazardous Industrial Waste Constituents Found in Case Studies,
ISDB, Listings Documents, and Effluent Guidelines by Chemical Class ............ 4-6
Exhibit 4-3 Lists Used to Identify Possible Non-Hazardous Industrial Waste Constituents ........ 4-8
Exhibit 4-4 Criteria Considered for Screening Non-Hazardous Industrial Waste
Constituents [[[ 4-10
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LIST OF EXHIBITS (Continued)
Exhibit 4-6 Persistence and Bioconcentration/Bioaccumulation Screening Results for
Possible Non-Hazardous Industrial Waste Constituents 4-16
Exhibit 4-7 Screening of High-Toxicity, Persistent, Bioaccumulative/Bioconcentrating
Possible Non-Hazardous Industrial Waste Constituents Against TRI Release
Volumes 4-17
Exhibit 4-8 Possible Non-Hazardous Industrial Waste
Constituents by Chemical Class 4-21
Exhibit 4-9 Screening of Known Non-Hazardous Industrial Waste Constituents Against
TRI Release Volumes 4-22
Exhibit 4-10 Toxicity Summary of Known and Possible Non-Hazardous Industrial Waste
Constituents 4-26
Exhibit 4-11 Potential Endocrine Disrupters 4-27
Exhibit 4-12 TRI Releases and Non-Confidential TSCA Production Volume Data for the Known
and Possible Non-Hazardous Industrial Waste Constituents 4-28
Exhibit 4-13 Volatility, Persistence, and Bioaccumulation/Bioconcentration Summary Potential of
Known and Possible Non-Hazardous Industrial Waste Constituents 4-29
Exhibit 4-14 LNAPL/DNAPL Formation Potential of Known and Possible Non-Hazardous
Industrial Waste Constituents 4-32
Exhibit 4-15 Multiple Screening Criteria Applied to Known and Possible Non-Hazardous
Industrial Waste Constituents 4-34
Exhibit 4-16 Lowest Proposed HWIR-Waste Exit Levels for Known and Possible Non-
Hazardous Industrial Waste Constituents 4-36
Exhibit 4-17 Potential Acute Hazards Associated with Known and Possible Non-Hazardous
Industrial Waste Constituents 4-39
Exhibit 4-18 Potential Gaps in the Hazardous Waste Characteristics Identified Based on the
Hazardous Properties of Known and Possible Non-Hazardous Industrial Waste
Constituents 4-41
Exhibit 5-1 Constituents/Properties with SMCLs Found in Release Descriptions 5-2
Exhibit 5-2 Chemicals from Release Descriptions with Low Odor Thresholds 5-3
Exhibit 5-3 Initial List of, Large-Scale Environmental Problems 5-4
Exhibit 5-4 U.S. Sources of Air Pollutants of Concern for Great Waters 5-5
Exhibit 6-1 State Toxicity Characteristics: Additional Constituents and More Stringent
Regulatory Levels 6-3
Exhibit 6-2 State Toxicity Criteria Applied to Whole Waste (Representative Sample) 6-4
Exhibit 7-1 Summary of Potential Gaps in the Hazardous Waste Characteristics 7-2
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LIST OF EXHIBITS (Continued)
Page
Exhibit 8-1 Estimated Generation of Non-Hazardous Industrial Waste by Major Industry
Group . ; 8-4
Exhibit 8-2 Chemicals Exceeding Health-Based and Non-Health-Based Regulatory Levels
in the Release Descriptions for Non-Hazardous Waste Management 8-6
Exhibit 8-3 Numbers of Chemical Detections and Frequencies of Regulatory Exceedences
in Release Descriptions 8-7
Exhibit 8-4 Most Frequently Occurring Constituents in the Release Descriptions 8-9
Exhibit 8-5 Occurrence of Waste Constituents by Industry Group 8-11
Exhibit 8-6 Non-Hazardous Industrial Waste Constituents Reported Released by Industry 8-19
Exhibit 8-7 Volume of Non-Hazardous Industrial Waste Managed in Land-Based Facilities
in 1985 8-22
Exhibit 8-8 Active Non-Hazardous Industrial Waste Management Units in 1985 by Major
Industry Group 8-23
Exhibit 8-9 Non-Hazardous Industrial Waste Management by Industry and Waste Type
from TSDR and ISDB 8-25
Exhibit 8-10 Waste Management Unit Types in the Release Descriptions 8-30
Exhibit 9-1 TC Constituents with Effluent Limits Established under CWA 9-5
Exhibit 9-2 CWA Effluent Limitations Relevant to Certain Known Non-Hazardous
Industrial Waste Constituents 9-6
Exhibit 9-3 CWA Coverage of Industries Represented in Release Descriptions 9-7
Exhibit 9-4 TC Constituents with SDWA MCL Levels 9-8
Exhibit 9-5 MCLs for Known Non-Hazardous Industrial Waste Constituents of Concern in
Groundwater Pathways 9-9.
Exhibit 9-6 TC Constituents Designated as HAPs under CAA 9-11
Exhibit 9-7 CAA Hazardous Air Pollutants (HAPs) Specified for Potential Gap
Constituents 9-12
Exhibit 9-8 CAA Coverage of Industries Represented in Release Descriptions 9-13
Exhibit 9-9 "Status of Pesticides That are TC Analytes or Known Non-Hazardous
Industrial Waste Constituents 9-14
Exhibit 9-10 TC Constituents with Established OSHA PELs 9-17
Exhibit 9-11 OSHA PELs Specified for Known Non-Hazardous Industrial Waste
Constituents 9-18
Exhibit 9-12 Potential Gaps and Potential Non-RCRA Regulatory Control 9-19
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LIST OF EXHIBITS (Continued)
Exhibit 10-1 Evaluation of Potential Gaps Associated With the Ignitability, Coirosivity, and
Reactivity (ICR) Characteristics 10-4
Exhibit 10-2 Evaluation of Potential Gaps Associated with Toxicity Characteristic Analytes
and TCLP 10-9
Exhibit 10-3 Evaluation of Potential Gaps Associated with Non-TC Chemicals 10-15
Exhibit 10-4 Evaluation of Potential Gaps Associated With Certain Large-Scale
Environmental Problems 10-24
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EXECUTIVE SUMMARY
The U.S. Environmental Protection Agency (EPA), Office of Solid Waste has
investigated potential gaps in the current hazardous waste characteristics promulgated under
the federal Resource Conservation and Recovery Act (RCRA). This report, the Hazardous
Waste Characteristics Scoping Study, presents the findings of that investigation.
THE SCOPING STUDY: AN EARLY STEP
This study is a first step for the Agency in fulfilling a long-standing goal to review the
adequacy and appropriateness of the hazardous characteristics. The study also fulfills an
obligation in a consent decree with the Environmental Defense Fund (EDF).
The study is by design a scoping study and, therefore, does not conclusively identify
particular chemical classes for regulation, or fundamental flaws in the overall regulatory
framework requiring immediate regulatory action. However, the study does identify several
key areas that merit further analysis due to the significant potential for improving hazardous
waste management practices and protection to health and the environment. Thus, the scoping
study provides a catalogue of potential gaps in the hazardous waste characteristics.
The Agency considers that this study is one very critical component of a broader array
of efforts underway to review and improve the RCRA program, to ensure that regulation is
appropriate to the degree of risk posed by hazardous wastes and waste management practices.
Efforts involve both regulatory and de-regulatory actions, as appropriate for specific wastes
and waste management practices.
STUDY PROCESS AND FINDINGS
Review of Current Characteristics
The review of the current characteristic regulations evaluated the protectiveness of the
characteristics against the risks they were intended to address and also risks they were not
specifically intended to address. For example, EPA evaluated risks that are now addressed by
the Toxicity Characteristic (TC), e.g., direct ingestion of groundwater, by considering new
groundwater modeling techniques that have been in use since the promulgation of the current
TC levels, as well as any changes to the toxicity values on which the original levels were
based. In addition, EPA evaluated risks from other exposure pathways and to ecological
receptors, which are both risks not intended to be protected by the original TC.
The review of the current TC regulatory levels suggests that: (1) further analysis
of the current TC regulatory levels should be conducted using new groundwater
modeling techniques, as well as considering changes to toxicity values for specific
constituents; and (2) non-groundwater pathways and ecological receptors-not currently
addressed by TC provisionsmay be of potential concern. The study included some
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screening analyses of potential air releases from surface impoundments and land application
units. The Agency found that inhalation risk levels for a significant number of current TC
constituents at the fenceline (under certain exposure conditions) exceeded the allowable risk
levels upon which the TC is based.
Waste piles and land application units may be of special concern for ecological
receptors due to surface runoff. .Thirteen TC constituents have regulatory levels that are
10,000 or more times higher than Ambient Water Quality Criteria concentrations, with four of
these being at least 100,000 times higher, suggesting that the level of protectiveness of the TC
may not be very high for ecological receptors.
The study also identifies the need to examine a broader array of leaching
procedures, in addition to the Toxicity Characteristic Leaching Procedure (TCLP), to
better predict environmental releases from various waste types and waste management
conditions. Notable examples are the inability of the TCLP to predict significant releases
under highly alkaline conditions or to media other than groundwater, or to serve as a leaching
procedure for oily wastes.
The most obvious potential gap identified for the ignitability and reactivity
characteristics is the reference to outdated DOT regulations. Other potential gaps
identified for these characteristics include the exclusion of combustible liquids and lack of
specific test methods.for non-liquids for ignitability; exclusion of corrosive solids, not
addressing corrosion of non-steel materials and solubilization of non-metals, and whether pH
limits are adequately protective for corrosivity; and, an overly-broad definition and lack of
specific test methods for reactivity.
Releases from Non-Hazardous Industrial Waste Facilities
The Agency identified actual releases of non-hazardous waste constituents as one
means of finding potential problem constituents and management activities. EPA reviewed
data on non-hazardous industrial waste management activities that was readily available from
state monitoring and compliance files. The Agency focused on wastes that are not currently
regulated as hazardous (by virtue of being listed or exhibiting a characteristic) to identify
releases potentially causing human health or environmental damages.
The Agency considered three major factors in judging whether a release was an
appropriate case study for this evaluation. A release had to meet all three of the following
criteria to be included: (1) The source of contamination had to be a waste management unit or
other intended final disposal area that received only non-hazardous industrial waste; (2) A
release from a waste management unit must have caused contamination at levels of potential
concern (constituent-specific concentrations that exceed federal standards or state guidelines
or regulations); and, (3) Documented evidence must be available to support the exceedences
referred to in (2).
EPA found 112 environmental release case studies in 12 states with readily available
(and not necessarily representative) data on non-hazardous waste management units. The
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releases were-found from facilities in 15 (2-digit) Standard Industry Classification (SIC)
industries. The top four categories were: SIC 49: Electric, Gas, and Sanitary Services
(refuse-side only); SIC 26: Paper & Allied Products; SIC 28: Chemical & Allied Products;
and, SIC 20: Food & Kindred Products.
Over 90 percent of the releases were from landfills or surface impoundments and
nearly all (98 percent) involved groundwater contamination. This is most likely because
groundwater monitoring is the most common method for detecting releases from waste
management units.
Many of the chemical constituents most commonly detected above a regulatory
level are already addressed in the current TC, even though the release occurred from
non-hazardous waste management The 20 constituents most commonly detected above a
regulatory level are inorganics. The constituents that exceeded state groundwater protection
standards or health-based federal drinking water standards most frequently were lead,
chromium, cadmium, benzene, arsenic and nitrates. All of these, with the exception of
nitrates, are current TC constituents. Organic constituents, both TC and non-TC, were also
identified hi the case studies, however, they were detected less frequently than the inorganic
toxicity characteristic constituents.
This collection of release descriptions is not statistically representative of problem
industries nor intended to identify particular problem facilities. The Agency believes that
the case studies are indicative of the type of releases associated with the management of non-
hazardous wastes in the types of facilities identified. The Agency also believes that
information on releases from past waste management practices is useful in demonstrating the
potential for human health or environmental damage.
Non-TC Chemical Constituents
In reviewing chemicals and chemical classes not currently regulated by the TC,
EPA found in excess of 100 constituents that potentially occur hi waste and may pose
significant risks. EPA reviewed 37 regulatory or advisory lists of chemicals to identify
possible constituents of non-hazardous wastes. EPA also compiled a list of chemicals which
are "known" to be constituents of non-hazardous wastes because they were identified hi the
environmental release case studies or other Agency data sources on non-hazardous industrial
wastes. EPA screened these chemicals and narrowed the list to possible constituents of non-
hazardous waste that, by virtue of their toxicity, fate and transport properties, or exposure
potential, could pose significant risks to human health and/or the environment.
These chemicals were both inorganics and organics, and include volatiles, non-
volatile organics, PAHs and pesticides. Because of the large number of constituents
identified as candidates and the limited time available for the scoping study, no risk analyses
were conducted. However, it may be a reasonable next step to assess the potential risks for a
subset of these constituents.
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Natural Resource Damages/Large-Scale Environmental Problems
The Agency examined the potential for broad environmental impacts from non-
hazardous waste management. These impacts may include damages to natural resources
which diminish the value and usability of a resource without threatening human health, as
well as possible contributions to regional and global environmental problems.
With respect to groundwater contamination, over 80 percent of the facilities
identified in the case studies discussed earlier had releases exceeding secondary drinking
water standards (non-health based standards). These releases were identified because
exceedence of secondary standards may reduce the useability and, therefore, the value of the
groundwater. Iron, chloride, sulfate and manganese were among the most frequently detected
constituents exceeding secondary standards.
In reviewing air deposition of toxic constituents to great waters, the Agency found a
number of TC constituents, as well as some other chemicals identified in the study. However,
it was not possible to assess the importance of waste to air deposition of toxics to the great
waters.
State-Only Hazardous Waste Regulations
Some states have adopted hazardous waste identification rules that are broader or
more stringent than federal RCRA Subtitle C regulations. These expansions reflect state
judgements about gaps hi the federal program. Data on hazardous waste regulations from
eight states, California, Michigan, New Hampshire, Oregon, Rhode Island, Texas,
Washington, and New Jersey were considered. Several states regulate additional constituents
beyond the TC list ( 25 for California, 9 for Michigan, and 1 for Washington). California
also applies a more aggressive leaching test, the waste extraction test (WET) to wastes.
California also has a test for combinations of hazardous constituents, in which a combined
concentration of the listed constituents cannot exceed 0.001 percent as a total in the waste.
Four states also .apply acute toxicity values (LD50 or LC50) for human or ecological toxicity
to the whole waste.
NEXT STEPS
The potential gaps and areas of health and environmental concern identified here will
require further, more detailed examination before regulatory action can be undertaken. For
example, the study highlights risks to ecological receptors and possible inhalation risks to
humans as potential gaps, as well as further evaluation of the adequacy of the TCLP. These
topics were found to be potential gaps hi more than one area of the study and will likely be
specific areas of further investigation.
Following release of this report, the Agency will engage in a variety of outreach
activities in identifying appropriate next steps. While the Agency considers this a final report,
comments from interested members of the public are solicited and will be used to help
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identity and structure follow-on activities. As noted above, revisions to the characteristics
program will likely, in the long run, involve both regulatory and de-regulatory activities.
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CHAPTER 1. INTRODUCTION
The U.S. Environmental Protection Agency (EPA), Office of Solid Waste has investigated
potential gaps in the current hazardous waste characteristics promulgated under the federal Resource
Conservation and Recovery Act (RCRA). This report, the Hazardous Waste Characteristics Scoping
Study, presents the findings of that investigation. Chapter 1 presents background information on the
Scoping Study as follows:
Section 1.1 describes the purpose and scope of the Scoping Study;
Section 1.2 discusses relevant aspects of the RCRA hazardous waste and non-
hazardous waste programs;
Section 1.3 summarizes the methodology used to prepare the Scoping Study,
and
Section 1.4 outlines the remaining chapters and appendices of the Study.
1.1 Purpose and Requirements of the Hazardous Waste Characteristics Scoping Study
As stipulated under an amended consent decree with the Environmental Defense Fund (EDF)
(presented in the text box below), the Agency has investigated potential gaps in the coverage of the
existing RCRA hazardous waste characteristics. The purpose of this Study is to identify potential gaps
in coverage and to investigate the nature and extent of such gaps. Based on the results of the Study,
EPA will seek input from interested parties and determine the appropriate course of action to further
address any significant potential gaps identified in the Study.
Agreement for Hazardous Waste Characteristics Scoping Study
The Administrator shall perform a study of potential gaps in the coverage of the existing
hazardous waste characteristics. The purpose of the study is to investigate if there are gaps in
coverage, and the nature and extent of the gaps identified. The potential gaps in coverage to be
addressed'in the study [shall] incorporate both waste management practices and possible impacts to
human health and the environment. With respect to waste management practices, the study shall, at
a minimum, address releases from non-hazardous waste surface impoundments; waste piles; land
treatment units; landfills; and various forms of use constituting disposal such as road application,
dust suppression or use in a product applied to the land. Human health and environmental impacts
to be addressed by the study shall include, but not be limited to: (a) impacts via non-groundwater
exposure pathways, both direct and indirect, to human and ecological receptors; (b) impacts via the
groundwater pathway to ecological receptors; (c) the potential for formation of non-aqueous phase
liquids in groundwater; and (d) impacts via the groundwater pathway to human receptors caused by
releases of toxic constituents not included in the current toxicity characteristic, such as EPA-
classified carcinogens, priority pollutants identified in the Clean Water Act, and solvents used for
purposes other than degreasing. The Administrator shall complete the study by November 15,
1996, and shall provide the plaintiff with two copies of the study immediately upon completion.
Environmental Defense Fund, Inc. v. Browner. Civ. No. 89-0598, order granting stipulated motion
of EDF and EPA for amendment of consent decree. May 17, 1996, pp. 18-19.
Page 1-1
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1.2 Regulatory Background
This report focuses on wastes that are not currently regulated as hazardous (by virtue of being
listed or exhibiting a characteristic). Industrial wastes are classified either as "hazardous waste" and
managed under Subtitle C of the Resource Conservation and Recovery Act (RCRA) or as "non-
hazardous waste" and managed under Subtitle D of RCRA, primarily under state programs. In the
context of this report, the term "non-hazardous industrial waste" broadly refers to waste that is neither
municipal solid waste, special waste, nor considered a hazardous waste under Subtitle C of RCRA. A
brief description of the Agency's hazardous and non-hazardous waste classification systems is provided
below.
Subtitle C of RCRA, as amended, establishes a federal program for the comprehensive
regulation of hazardous waste. Section 1004(7) of RCRA defines hazardous waste as
"a solid waste, or a combination of solid wastes, which because of its quantity,
concentration, or physical, chemical, or infectious characteristics may: (a) cause, or
significantly contribute to an increase in mortality or an increase in serious irreversible,
or incapacitating reversible, illness; or (b) pose a substantial present or potential hazard
to human health or the environment when improperly treated, stored, transported,
disposed of, or otherwise managed."
Under RCRA Section 3001, EPA is charged with defining which solid wastes are hazardous by
identifying the characteristics of hazardous waste and listing particular hazardous wastes.
Current hazardous waste characteristics are ignitability, corrosivity, reactivity, and toxicity.
The Agency's definitions of ignitability and reactivity have not changed materially since their adoption
in 1980.1 The Agency's definition for corrosivity was last revised in 1993.2 The Agency's current
definition of toxicity was promulgated in 1990,3 replacing the Extraction Procedure (EP) leach test
with the Toxicity Characteristic Leaching Procedure (TCLP) and adding 25 organic chemicals to the
list of toxic constituents of concern and establishing their regulatory levels. The Agency's definition
of toxicity was last revised in 1993;4 however, this revision did not alter the framework for defining
this characteristic.
A solid waste is classified as listed hazardous waste if it is named on one of the following four
lists developed by EPA:
Nonspecific source or F wastes (40 CFR 261.31). These are generic wastes,
commonly produced by manufacturing and industrial processes. Examples
-include spent halogenated solvents used in degreasing and wastewater
treatment sludge from electroplating processes as well as dioxin wastes, most
1 45 Federal Register 33084, May 19, 1980.
2 58 Federal Register 46049, August 31, 1993.
3 55 Federal Register 26987, June 29, 1990.
4 58 Federal Register 46049, August 31, 1993.
Page 1-2
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of which are "acutely hazardous" wastes due to the danger they present to
human health or the environment.
Specific source or K wastes (40 CFR 261.32). This list consists of wastes
from specifically identified industries such as wood preserving, petroleum
refining, and organic chemical manufacturing. These wastes typically include
sludges, still bottoms, wastewaters, spent catalysts, and residues.
Discarded commercial chemical products or P and U wastes (40 CFR
261.33(e) and (f)). The third and fourth lists consist of specific commercial
chemical products and manufacturing chemical intermediates. They include
chemicals such as chloroform and creosote, acids such as sulfuric acid and
hydrochloric acid, and pesticides such as DDT and kepone.
Disposal of non-hazardous solid waste is regulated under Subtitle D of RCRA, Subtitle D
wastes include municipal solid waste, special waste, and industrial waste.
Municipal solid waste includes household and commercial solid waste.
Household waste is defined as any solid waste (including garbage, trash, and
sanitary waste in septic tanks) derived from households (including single and
multiple residences, hotels and motels, bunkhouses, ranger stations, crew
quarters, campgrounds, picnic grounds, and day-use recreation areas) (40 CFR
258.2). Commercial waste refers to all types of solid waste generated by
stores, offices, restaurants, warehouses, and other non-manufacturing activities,
excluding residential and industrial wastes (40 CFR 258.2).
Special waste, as used in this document, refers to oil and gas exploration and
production waste, fossil fuel combustion wastes, cement kiln dust, and solid
waste from the extraction, beneficiation, and processing of ores and minerals
(40 CFR 261.4).
Non-hazardous industrial waste refers to solid waste generated by
manufacturing or industrial processes that is not a hazardous waste regulated
under Subtitle C of RCRA or a special waste (40 CFR 258.2).
Under Subtitle D, the management of non-hazardous industrial waste in land-based units must
comply with 40 CFR Part 257, which establishes minimum federal standards for the management and
siting of land-based units. Individual states are responsible for implementing 40 CFR Part 257 under
their own authority. They have adopted statutory and regulatory frameworks for management of non-
hazardous industrial wastes. These requirements vary widely from one state to another in terms of
their design and operating requirements, monitoring requirements, and other management requirements
such as recordkeeping, closure, post-closure care, and financial responsibility. Even within a given
state, the non-hazardous industrial waste requirements may vary from facility to facility depending on
the characteristics of the wastes managed and the environmental setting of the waste management unit.
The Agency is currently developing "voluntary guidelines" for non-hazardous industrial waste
management to better ensure that this waste is managed in a manner that is protective of human health
and the environment.
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13 Approach for Studying Potential Gaps in the Hazardous Waste Characteristics
As shown in Exhibit 1-1, the general approach EPA used to perform the Scoping Study has
nine steps. Each of these steps is discussed below.
Step 1: Characterize Releases from Non-Hazardous Industrial Waste Management
The Agency conducted detailed investigations to identify specific instances of environmental
contamination resulting from the management of non-hazardous industrial wastes. These case studies
provide real-world information on releases of these wastes into the environment, the chemicals
released and their concentrations, and the waste management practices and industries involved. The
preliminary findings of such research were presented in a draft report entitled "Hazardous Waste
Characteristics Scoping Study: Environmental Release Descriptions" (September 24, 1996). EPA held
a public meeting on October 10, 1996 to explain and obtain comments on the draft report. EPA has
considered and, where appropriate, incorporated these comments in preparing this Scoping Study.
Chapter 2 summarizes these investigations and Appendix A presents the individual environmental
release descriptions.
Step 2: Categorize Risks Associated with Non-Hazardous Industrial Waste Management
This step identifies categories of risks to human health and the environment mat may result
from non-hazardous industrial waste management. The underlying premise of diis step is that a gap in
the hazardous waste characteristics is any significant risk to human health or the environment
associated with non-hazardous industrial waste management that could be, but is not, addressed by the
current characteristics. Thus, this assessment deals with both:
Hazards that die current hazardous waste characteristics were intended to
address, namely physical hazards such as fire and explosion and toxic
groundwater contamination near waste management facilities; and
Hazards that the characteristics were not intended to address, such as non-
groundwater pathway exposures to toxins, damages to ecological receptors, and
natural resource damages.
EPA identified risks by types of receptors, types of toxic effects and physical hazards,
exposure pathways, and time and spatial scales, as described in Section 3.1. The search for potential
risks used broad definitions of risk and adverse effects and addressed all aspects of non-hazardous
industrial waste management, without any prejudgment as to the likelihood mat a risk was significant,
whether it could be best addressed by die characteristics, or whedier it was already addressed by other
regulations. The results of this risk classification step were used in identifying and evaluating
potential gaps, as described below.
Step 3: Review the Existing Characteristics
The identification of potential gaps continues with a review of the existing definitions of the
characteristics. This step is next for two reasons. First, limitations in the characteristics' effectiveness
in reducing the risks they were intended to address may constitute important potential gaps. When the
characteristics were promulgated, the Agency identified physical hazards and acute toxic hazards
during transport and disposal activities and chronic exposure to groundwater contaminated with waste
Page 1-4
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Exhibit 1-1
Scoping Study Approach
Stepl
Describe actual
releases from
non-hazardous industrial
waste management
Step 2
Categorize risks
from non-hazardous
industrial waste
management
Step 3
Identify potential
gaps inherent in
current
characteristics
i
Step 7
Identify industries and
waste management
practices associated
with potential-gaps
I
Step 4
Identify potential
gaps from
"known" and
"possible"
non-hazardous
industrial waste
constituents
StepS
Identify potential
gaps associated
with large-
scale environmental
problems and
natural
resource damages
i
1
Step 6
Identify potential
gaps addressed
by expanded
state hazardous
waste
characteristics
and listings
StepS
Analyze extent to
which regulatory
programs already
address potential gaps
Step 9
Present integrated evaluation
of nature and extent of
potential gaps
Page 1-5
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constituents as being among the most important waste management risks. Reducing these risks
remains an important goal of the characteristics. Second, this analysis lays the groundwork for
evaluating other potential gaps.
Step 3 begins by examining the definitions and test methods of the ignitability, corrosivity, and
reactivity (ICR) characteristics, which are essentially unchanged since they were promulgated in 1980.
EPA reviewed the assumptions and approaches used to develop these characteristics and compared the
characteristics to approaches taken to controlling similar hazards under other federal and state
regulatory schemes. Step 3 also examines the definition of the toxicity characteristic (TC), which was
designed to protect against human health risks from exposure to hazardous waste constituents released
to groundwater. EPA reviewed new information on the toxicity, fate, and transport of the TC
constituents and improvements in groundwater modeling since the TC was revised in 1990. The
Agency also examined the potential risks from TC constituents through inhalation, surface water, and
indirect pathways and to ecological receptors. Chapter 3 describes these analyses.
Step 4: Identify Gaps Associated with Non-TC Chemicals
Potential gaps in the hazardous characteristics from non-TC chemicals are identified by, first,
identifying two groups of constituents:
"Known" non-hazardous industrial waste constituents: constituents
"known" to be present in non-hazardous industrial wastes, based on the data
gathered in the environmental release descriptions in Step 2, EPA's 1987
Telephone Screening Survey of non-hazardous industrial waste management
facilities, EPA effluent guideline development documents, and recent
hazardous waste listing determinations.
"Possible" non-hazardous industrial waste constituents: constituents on
various regulatory or advisory lists, which were screened for their toxicity,
fate, and transport properties and for a proxy of their occurrence in non-
hazardous industrial waste, using available environmental release data from the
1994 Toxics Release Inventory.
Then, these two lists of constituents are evaluated and compared and chemicals are classified by
physical properties, chemical composition, use, and origin. Finally, potential gaps were identified by
applying multiple hazard-based screening criteria to specific chemicals and chemical classes.
Chapter 4 describes these analyses.
Step 5r Identify Potential Gaps Associated with Certain Natural Resource Damages and
Large-Scale Environmental Problems
As discussed above, steps 3 and 4 respectively examine potential gaps inherent in the current
hazardous waste characteristics and associated with adverse human health or localized ecological
effects from constituents not addressed by the toxicity characteristic. Step 5 addresses a third set of
risks associated with non-hazardous industrial waste management: damages to natural resources that
may not have direct human health or ecological effects, and large-scale environmental problems. The
specific risks addressed are:
Page 1-6
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Pollution of groundwater by constituents that diminish the value and usability of the
resource without threatening human health;
Air pollution through odors that harm the quality of life but may not have severe
health effects; and
Large-scale environmental problems, including air deposition to the Great Waters,
damages from endocrine disrupters and airborne particulates, global climate change,
red tides, stratospheric ozone depletion, tropospheric ozone and photochemical air
pollution and water pollution.
Chapter 5 presents these analyses.
Step 6: Review State Expansions of TC and State Listings
Several states have expanded their hazardous waste management programs to regulate as
hazardous certain wastes or waste constituents that are not hazardous under the federal program. Step
6 examines how states have expanded their toxicity characteristics and have listed as hazardous certain
wastes that are not listed under the federal program. (Step 3 examines how states have regulated
additional wastes by expanding their ICR characteristics.) These expansions beyond the federal
hazardous waste identification rules reflect state judgments about gaps in the federal hazardous waste
program and thereby constitute potential gaps that may merit further investigation. Chapter 6 presents
this analysis. (Chapter 7 summarizes the potential gaps identified in Chapters 3 through 6.)
Step 7: Evaluate the Industries and Waste Management Practices Associated with
Potential Gaps
The evaluation of potential gaps asks two basic questions: (1) What do the qualitative and
quantitative indicators of risk show about the potential gaps? and (2) To what extent are the risks
associated with the potential gaps addressed by other regulations? Steps 7, 8, and 9 address these
questions. Step 7 addresses aspects of the first question. Specifically, it assesses the following:
The amount of non-hazardous industrial wastes generated by various industries;
The frequency with which various chemicals were detected or reported in
releases from various industries;
The management methods associated with the major non-hazardous industrial
-waste generators; and
The management practices associated with documented environmental releases
of non-hazardous industrial wastes.
Because of data limitations, EPA could not evaluate all potential gaps against all of these criteria.
Instead, this step focuses principally on the potential gaps identified in Steps 3 and 4. Chapter 8
presents this analysis.
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Step 8: Assess Regulatory Programs' Coverage of Potential Gaps
The second major issue in evaluating potential gaps is the extent to which the risks are
controlled by existing regulatory or other environmental programs. As noted above, risk-related gaps
were identified solely in terms of their relationship to non-hazardous industrial waste management, and
not with regard to whether they might be controlled under regulatory or other programs. Chapter 9
discusses how major federal and state regulatory programs may address some of the risks represented
by the potential gaps. To the extent mat they are already addressed or could be addressed more
effectively by programs other than the hazardous waste regulations, the potential gaps may not merit
further attention by the RCRA Subtitle C program.
Step 9: Present Integrated Evaluation of Nature and Extent of Potential Gaps
In the final step of the methodology, which is presented in Chapter 10, EPA integrates and
summarizes all of the lines of evidence relating to particular potential gaps in the hazardous waste
characteristics. The summary is presented in the form of several tables. This section also reviews the
major data gaps and uncertainties of the analysis.
1.4 Report Outline
This Scoping Study is organized in the same order as the methodology outlined above.
Chapter 2 characterizes releases from non-hazardous industrial waste management;
Chapter 3 categorizes risks associated with potential gaps in the characteristics and
reviews the existing characteristics to identify potential gaps;
Chapter 4 identifies potential gaps associated with non-TC chemicals;
Chapter 5 identifies potential gaps associated with certain natural resource damages
and large-scale environmental problems;
Chapter 6 identifies potential gaps in the characteristics by reviewing how selected
states have expanded the TC and listed wastes that are not listed as
hazardous under the federal program;
Chapter 7 summarizes the potential gaps identified in Chapters 3 through 6;
Chapter 8 evaluates the extent of the risks presented by potential gaps;
Chapter 9 discusses how major federal and state regulatory programs address the
risks represented by the potential gaps; and
Chapter 10 presents an integrated summary evaluation of the nature and extent of
potential gaps and the associated major analytical limitations and describes
the framework that the Agency will apply in developing a plan for
addressing potential gaps in the hazardous waste characteristics identified
in this Study.
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The Study also includes several appendices. Appendix A describes the individual
environmental releases summarized in Chapter 2. Appendix B discusses several data sources used to
identify environmental releases that were not successful in finding releases meeting EPA's stringent
selection criteria. Appendix C provides a detailed comparison of the ICR characteristics to related
approaches under other federal and state programs. Finally, a separate background document contains
detailed information and analysis that supplements the screening-level risk analysis presented in
Chapter 3 and the identification of "possible" non-hazardous industrial waste constituents in Chapter 4.
Page 1-9
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CHAPTER 2. RELEASES FROM NON-HAZARDOUS
INDUSTRIAL WASTE MANAGEMENT UNITS
This chapter presents the methodology and results of the Agency's efforts to identify
contamination resulting from the management of non-hazardous industrial wastes. The Agency
prepared a draft report entitled "Hazardous Waste Characteristics Scoping Study: Environmental
Release Descriptions" which was released for public comment on September 25, 1996 (see 61 Federal
Register 50295). This chapter summarizes the revised report, incorporating relevant comments on the
draft report.
This chapter is composed of three sections:
Section 2.1 discusses the criteria, information sources, and methodology used
to select releases to include in the report;
Section 2.2 summarizes the release descriptions and presents findings of the
study; and
Section 2.3 presents the major limitations of the study.
The environmental release descriptions described in this chapter are presented in Appendix A
of this Scoping Study.
2.1 Methodology
Based on 1985 data, 7.6 billion tons of non-hazardous industrial waste are generated and
managed on-site annually by 17 major industries in the United States. Despite this large volume of
non-hazardous industrial waste, EPA has few data concerning the releases, human health impacts, or
environmental damages caused by such wastes. To identify such releases for purposes of the Scoping
Study, the Agency reviewed readily available information from a wide variety of data sources. The
purpose of this review was not to estimate risks posed, but rather to characterize releases due to non-
hazardous industrial waste management practices. This section discusses the criteria and methodology
used to select releases.
2.1.1 Criteria For Selecting Releases
The Agency considered three major factors in judging whether a release is an appropriate case
study for this report. To be included, a release had to meet all three of the criteria described below:
1. Source of Release. The source of contamination had to be a waste management unit
that received only non-hazardous industrial waste. Releases were excluded if:
a. Evidence suggested that the management unit also received municipal solid
waste, special waste, or RCRA hazardous waste. Many facilities manage
municipal, hazardous, and special wastes in the same waste management units
as non-hazardous industrial waste. Releases from such units were not included
in this report.
Page 2-1
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3.
c.
d.
The source of contamination could not be attributable solely to a non-
hazardous industrial waste management unit. Releases were excluded where
contamination (1) was detected at or near the facility, but the source of
contamination was unknown; (2) was not from a waste management unit (e.g.,
was a product spill); or (3) was from a combination of non-hazardous
industrial waste unit(s) and municipal, special, or hazardous waste unit(s).
The source of contamination was industrial wastewater discharges that are
point source discharges regulated under Section 402 of the Clean Water Act, as
amended.
The management method employed would be illegal in most states today.
(Facilities were included if management practices would be legal today, even if
no longer employed at a particular facility.)
Evidence of Damage. For purposes of the study, "damage" is considered to be a
release exceeding one of the levels described below. All exceedences were examined
for purposes of this scoping study. Exceedences may not actually represent significant
risks. To be included in the Study, a release from a waste management unit must have
caused contamination at levels of potential concern for that contaminated medium.
Levels of potential concern used for this criterion were often based on federal or state
drinking water standards for groundwater contamination and exceedences of
background concentrations for soil contamination. Federal drinking water standards
include maximum contaminant levels (MCLs) and secondary maximum contaminant
levels (SMCLs)1. State drinking water standards, which are often stricter than the
federal standards, also were considered. Releases were not included if contaminant
concentrations were above background concentrations but below levels of potential
concern. If at least one contaminant was detected at concentrations above a federal or
state standard, then data were collected and presented for all contaminants detected at
that site.
Test of Proof. Documented evidence must prove that a damage or danger from a
non-hazardous industrial waste management unit has occurred. Evidence was accepted
if it met one or more of the following three tests:
a.
b.
c.
Scientific investigation. Damages were found to exist as part of the findings
of a scientific study. Such studies include both extensive formal investigations
(e.g., in support of litigation or a state enforcement action) and the results of
technical tests (e.g., monitoring of wells);
Administrative ruling. Damages were 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 dangers; and/or
Court decision. Damages were found to exist through a ruling of a court of
law or through an out-of-court settlement.
SMCLs are based on aesthetic considerations (e.g., taste and odor) and are not federally enforceable.
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2.1.2 Approach For Identifying Releases
The Agency investigated eight major
data sources to identify potential releases:
State Industrial D programs;
State Superfund programs;
Federal Superfund program;
Draft EPA report on
construction and demolition
waste landfills;
Federal RCRA corrective action
program;
Other federal and state data
sources;
Newspapers; and
Other literature searches.
EPA identified 112 facilities with
environmental releases from 4 of the 8 data
sources. As a result, this section summarizes
the methodologies used to investigate only the
four sources that resulted in case studies.
Detailed descriptions of the other four
methodologies are presented in Appendix B.
Draft release descriptions were sent to facility
owners/managers for data verification before
inclusion in this final report.
2.1.2.1 State Industrial D Programs
Public Involvement
In the limited time available for preparing
this Scoping Study, the Agency implemented
a number of measures to involve the public
in this aspect of the data collection effort.
Specifically, the Agency contacted the States
and facilities identified in the release
descriptions to solicit comments on draft
versions of the release descriptions.
Concurrently, the Agency released a draft
version of its "Hazardous Waste
Characteristics Scoping Study:
Environmental Release Description" report to
the public for comment and review on
September 25, 1996 (see 61 Federal Register
50295). This report was made available
through the RCRA Information Center and
the internet via EPA's web page. Next, the
Agency conducted a public meeting on
October 10, 1996 in Arlington, Virginia to
solicit comments on the draft report. Finally,
the Agency released a draft version of the
individual release descriptions to the public
for comment and review on October 29, 1996
(see 61 Federal Register 55800).
As specified under RCRA Subtitle D, states are the primary regulators of non-hazardous solid
waste, also known as Subtitle D waste. EPA's role is largely limited to establishing guidelines for the
development and implementation of state plans, providing technical assistance, and approving plans
that comply with these requirements. States are responsible for developing and implementing their
own plans. EPA identified states with potential case studies, then reviewed the state files for those
potential case studies.
The Agency is currently preparing voluntary guidelines on management standards for non-
hazardous industrial wastes. As part of this effort, in 1995, the Agency contacted representatives from
every state in the continental United States and asked them to identify known or potential
environmental damages caused by non-hazardous industrial waste management units. The Agency
visited and reviewed state files at four of the five states that reported the largest number of potential
case studies, California, Texas, North Carolina, New Mexico, and Wisconsin, and prepared a report
2 "Issue Paper: Potential Damage Cases From On-Site Disposal of Non-Hazardous Industrial Waste," August
1995.
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summarizing the results of the visits.3 The Agency did not visit California because, at the time,
California was preparing a comprehensive report on its Solid Waste Assessment Test (SWAT)
program, which included detailed information on environmental releases at non-hazardous industrial
waste disposal sites.
For the Scoping Study, the Agency chose to
investigate seven additional states based on the
reported numbers of potential case studies for these
States. Overall, the Agency focused its review of
non-hazardous industrial waste data on 12 of the 16
states that indicated having at least 10 potential case
studies. The Agency limited its review to these 12
states due to significant time constraints associated
with the Scoping Study.
12 States Included in Analysis
California
Florida
Louisiana
Michigan
New Mexico
New York
North Carolina
Pennsylvania
Tennessee
Texas
Virginia
Wisconsin
As the first step in identifying relevant
releases or case studies, the Agency contacted the states by telephone to discuss the requirements and
purpose of the release descriptions. For states that housed their files regionally, the Agency contacted
each regional office with potential case studies. After scheduling appointments to review the state
files, the Agency visited states to review and collect information about the specific releases of non-
hazardous industrial wastes into the environment at concentrations of concern. The Agency did not
visit California. During these trips, the Agency reviewed readily available documentation on each
potential case study and collected documentation for only those releases that appeared to meet all three
of the criteria described in Section 3.1.1. Over 80 percent of the facilities identified as potential case
studies were excluded from further review, primarily because the facilities co-disposed non-hazardous
industrial waste with municipal, hazardous, or special waste, or because the environmental damages
discovered at the facility could not be directly linked to a non-hazardous industrial waste management
unit. On an as-needed basis, EPA also made follow-up contact with state personnel most
knowledgeable about particular sites to obtain additional relevant information.
To ensure that facility-specific information was accurately compiled and presented, the Agency
contacted the states and facilities by telephone to ask them to review the draft release descriptions
prepared for this report. The Agency sent each state and facility their release descriptions, asked for
their written comments on the descriptions, and incorporated relevant comments.
Review of California's Industrial D Data. In 1984, the California State legislature passed a
law that required testing of water and air media at all solid waste disposal sites.4 The law also
required California's State Water Resource Control Board to rank all solid waste disposal sites in
groups of ISO each, according to the threat these facilities or sites may pose to water quality.
California's legislation requires site operators to submit a water quality "solid waste assessment test"
(SWAT) report presenting the following information:
An analysis of the surface and groundwater on, under, and within one mile of
the solid waste disposal site to provide a reliable indication of whether there is
any leakage of hazardous waste constituents; and
3 "Damage Cases: On-Site Disposal of Non-Hazardous Industrial Waste," September 1995.
4 California Code of Regulations, Title 23, Section 13273.
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A chemical characterization of the soil-pore liquid in those areas that are likely
to be affected if the solid waste disposal site is leaking, as compared to
geologically similar areas near the solid waste disposal site that are known to
not have been affected by leakage or waste discharge.
To expedite the review of California's Industrial D data, the Agency obtained a copy of
California's Solid Waste Assessment Test database. The Agency reviewed the database to identify
those facilities believed to manage only non-hazardous industrial waste and found to have leaked waste
constituents outside the limits of the waste management unit at levels above California or federal
regulatory standards. California's waste classification system was used to identify facilities believed to
manage only non-hazardous industrial waste.
The review of Industrial D data from 12
states identified a total of 104 releases that met the
Agency's selection criteria. Hundreds of potential
cases were reviewed to identify these releases.
2.1.2.2 State Superfund Programs
Abandoned or uncontrolled hazardous
substance sites not addressed by the federal
Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA)
program may be subject to remediation under the
state Superfund programs. EPA believes that some of these sites may be contaminated with industrial
wastes that would not be hazardous under the current RCRA Subtitle C requirements.
To expedite the process of identifying
relevant sites and to cover the largest possible
percentage of state Superfund sites, the Agency
focused on the states with the largest programs.
These states were identified according to the
Environmental Law Institute's 1993 Analysis of
State Superfund Programs.5 In July 1996, the
Agency identified and contacted 13 states listed as
having at least 1,000 state Superfund sites.
Personnel from each of the 13 states were asked
whether they produce publicly available summaries
of their state Superfund programs. The Agency
obtained the most recent annual state Superfund
reports for Missouri, New Jersey, New York, and
Texas and obtained a printout of California's
database for review. Due to the significant time
constraints associated with its analysis, the Agency
did not pursue information from other states, which lacked detailed, readily available information on
their Superfund program.
Industrial D
Case
Criteria for Inclusion
California
Wisconsin
Tennessee
Louisiana
New Mexico
Texas
29
20
9
7
7
6
Studies Satisfying
in the Scoping Study
Florida 6
New York 6
North Carolina 6
Michigan 4
Virginia 3
Pennsylvania 1
State Superfund Programs
with > 1,000 Sites
California
Illinois
Indiana
Massachusetts
Michigan
Missouri
New Jersey
New York
Ohio
Pennsylvania
Tennessee
Texas
Wisconsin
= State had readily available information.
5 Environmental Law Institute, "An Analysis of State Superfund Programs: 50-State Study, 1993 Update,"
prepared for U.S. Environmental Protection Agency's Office of Emergency and Remedial Response, December 1993.
Page 2-5
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Short published site descriptions for nearly 1,000 state Superfund sites from 5 states,
California, Missouri, New Jersey, New York, and Texas, were reviewed to identify potential case
studies that meet the Agency's selection criteria. A total of 60 sites were identified as potential case
studies. The Agency contacted the five states by telephone to discuss the availability of existing
information on those 60 sites. Two states (New York and Texas) indicated that they had additional
information readily available for review. The Agency visited these states' Superfund offices to review
and the additional information. The Agency identified one case study from New York as meeting all
of the selection criteria.
2.123 Federal Superfund Program
The Agency investigated several CERCLA data sources to identify releases relevant to the
Scoping Study. The vast majority of the CERCLA sites were not expected to meet the Agency's
selection criteria for two reasons. First, the majority of the sites are contaminated with RCRA
hazardous wastes or with releases or spills from products. These sites will not meet the Agency's
selection criteria for source of release. Second, most of the CERCLA sites contaminated with non-
hazardous industrial wastes are also expected to be contaminated with hazardous wastes. Therefore, it
is unlikely that a non-hazardous industrial waste management unit will be identified as the source of
the release at a CERCLA site.
Due in part to the large number (over 1,300) of CERCLA National Priority List (NPL) sites
and the relatively small number of sites likely to meet the Agency's three release selection criteria, the
Agency attempted to identify potential case study sites through telephone discussions with Regional
EPA Superfund personnel and Regional members of the National Association of Remedial Project
Managers and the National On-Scene Coordinator Association. Although the Regional Contacts
agreed that the Agency should be able to identify at least a few case studies from the CERCLA
program, they often were unable to identify specific sites. EPA Superfund staff in Region 4, however,
identified two sites apparently meeting the Agency's selection criteria. The Agency visited Region 4's
Superfund office and reviewed and copied the relevant files for these two sites. One of the two sites
met the Agency's selection criteria.
The following federal Superfund data sources were also reviewed; however no releases
meeting the Agency's selection criteria were identified:
Record of Decision (ROD) database;
CERCLA Natural Resource Damage Claims;
CERCLA Characterization Database; and
Exposure assessments performed by the Agency for Toxic Substances and
-Disease Registry (ATSDR).
2.1.2.4 Construction and Demolition (C&D) Landfill Report
On May 18, 1995, EPA's Office of Solid Waste published a draft report entitled Damage
Cases: Construction and Demolition Waste Landfills. The report, prepared in support of EPA's
rulemaking (60 Federal Register 30963, June 12, 1995) on conditionally exempt small quantity
generators (CESQG),6 presents information on environmental releases from construction and
6 Conditionally exempt small quantity generators (CESQGs) are defined as generators of less than 100 kilograms
per month of hazardous waste. See 40 CFR 261.5.
Page 2-6
-------
demolition (C&D) waste landfills, which receive materials generated from the construction or
destruction of structures such as buildings, roads, and bridges. One purpose of the report was to
determine whether the disposal of C&D waste in landfills has threatened or damaged human health or
the environment.
The May 1995 report used three criteria to select potential C&D waste landfill damage cases.
The landfill received predominantly C&D waste, with or without CESQG
waste mixed in. C&D landfills known to have received significant quantities
of municipal, industrial, or hazardous wastes were excluded.
The use of the site as a C&D landfill had to be the only potential source of the
observed contamination. Sites located near other potential sources of the
contamination such as underground storage tanks were excluded.
There was documented evidence of groundwater contamination, surface water
contamination, or ecological damage at the site. "Contamination" was defined
as an increase in chemical constituent concentrations above background or an
exceedence of an applicable regulatory standard or criterion attributable to
releases from the site.
In preparing the May 1995 report, the Agency searched for C&D landfills meeting these
criteria using four information sources: existing studies of C&D landfills, materials available through
the federal Superfund program, representatives of EPA Regions, and representatives of state and
county environmental agencies.
The Agency identified 11 environmental releases in the May 1995 report. Although one of the
Agency's criteria, as listed above, was to eliminate C&D landfills that received significant quantities of
municipal or hazardous wastes, 5 of the 11 landfills received municipal, special, or hazardous wastes.
Therefore, for purposes of this report, the Agency eliminated these five C&D landfill cases.
Eliminating the landfills that managed even small quantities of municipal, special, or hazardous waste,
ensures that the reported damages were caused by the non-hazardous industrial wastes, thereby
meeting the Agency's selection criteria for the source of the release.
2.1.3 Release Profile Preparation
The release profiles presented in Appendix A to the Scoping Study were prepared using a
standard format. This format is discussed below. Because the release profiles were prepared under
significant time-constraints using readily available data, detailed descriptions of the facility, wastes,
and waste management practices could not be developed. The data often provided only a brief
description of the facility and focused primarily on the results of the environmental sampling
conducted at the facility.
"Facility Overview" discusses the facility's operations, how long the facility was or has been
in operation, the location of the facility, surrounding land uses, the geologic and hydrogeologic
conditions at the facility, and other environmental characteristics, provided this information was
available.
Page 2-7
-------
"Media Affected" identifies whether the damages are associated with groundwater, surface
water, soil, and/or ecological receptors.
"Wastes and Waste Management Practices" discusses the type(s) of wastes generated at the
facility and the practices employed to manage the wastes including descriptions of the individual waste
management units and groundwater monitoring practices, provided this information was available.
"Extent of Contamination" discusses the groundwater contamination, surface water
contamination, and/or soil contamination at the site. Constituents detected in groundwater or surface
water above background levels are identified and compared to applicable state and federal standards.
The maximum detected concentration for all tested constituents are given. In reporting exceedences of
state or federal standards, EPA attempted to exclude constituents whose upgradient or background
concentrations were as high as those in downgradient wells.
"Corrective Actions/Regulatory Actions" discusses any corrective or regulatory actions that
have been recommended, planned, or taken at the site.
"Source" simply identifies the information source(s) used to prepare the release profiles. The
main source of information was the facility-specific files located in state offices.
2.2 Results
This section discusses the findings of the review of release data. It begins by summarizing the
112 documented release descriptions using the following five categories:
Number of cases by state;
Number of cases by industry;
Number of cases by type of waste management method;
Type of media affected; and
Type and level of contaminants.
Later chapters of this report also present these and additional release description data.
2.2.1 Number of Cases By State
The 112 releases described in this chapter were found in 12 states. Because this report is a
Scoping Study, these case studies were not intended to be geographically or statistically representative
of the number of known or potential releases of non-hazardous industrial wastes identified by the
Agency. Although these case studies are not statistically or geographically representative, they do
illustrate the type of releases that have occurred from non-hazardous industrial waste management
units in various parts of the country, as shown hi Exhibit 2-1. The case studies were selected based on
the availability of data. Due to the limited time available to collect data, the Agency largely focused
its efforts on the states with the most available data on releases from non-hazardous industrial waste
management units. This process identified releases in most areas of the nation, except the northwest,
northern mountain states, and midwest. The states in these regions either were unable to identify any
or identified few potential case studies in the Agency's 1995 efforts to estimate the number of
potential releases from non-hazardous industrial waste management units by state.
Page 2-8
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Exhibit 2-1
Number of Release Descriptions By State
cgn014-1.cdr
The available data on facilities that manage non-hazardous industrial waste indicate that the
states addressed in this report manage some of the largest volumes of non-hazardous industrial waste.
Also, seven of the 12 states represented in this report are among the 10 states with the largest number
of on-site non-hazardous industrial waste management units in 1985. Exhibit 2-2 identifies the number
Exhibit 2-2
Number of Management Units & Volume of Waste Managed On-Site, by State (1985)
Rank by
Number
of Units
1
2
3
4
5
6
7
8
9
State
California
Texas
Wisconsin
Pennsylvania
Georgia
Illinois
Ohio
Vermont
Louisiana
Number of
Management
Units in 1985a
2,150
1,900
1,720
1,475
1,080
1,005
960
940
890
1985 Volume
Waste Managed
(Million tons/yr.)a
570
590
60
940
220
265
155
5
170
Number of Release
Descriptions
29
6
22
1
None
None
None
None
7
Page 2-9
-------
Exhibit 2-2 (continued)
Number of Management Units & Volume of Waste Managed On-Site, by State (1985)
Rank by
Number
of Units
10
12
13
14
15
21
41
State
North Carolina
Virginia
Michigan
New York
Florida
Tennessee
New Mexico
Number of
Management
Units in 1985a
855
800
785
740
740
510
140
1985 Volume
Waste Managed
(Million tons/yr.)a
240
150
210
30
310
245
10
Number of Release
Descriptions
6
6
4
8
7
9
7
aSource: "Telephone Screening Survey," U.S. Environmental Protection Agency, 1987.
of on-site management units and the volume of waste managed on-site in states. (See Chapter 8 for
further discussion of waste generation by industry.)
2.2.2 Number of Cases By Industry
The releases documented in this report were from facilities in 15 2-digit Standard Industry
Classification (SIC) codes. (Industry data are presented at the two-digit level because more specific
classification were not readily available for many facilities.) Over 31 percent of the cases involve
Electric, Gas, and Sanitary Services facilities (SIC 49). All of these facilities are in the refuse system
sector (SIC 4953). The top four SIC codes are SIC 49: Electric, Gas, and Sanitary Services, SIC 26:
Paper & Allied Products, SIC 28: Chemical & Allied Products, and SIC 20: Food & Kindred
Products. These four industry groups represent nearly 75 percent of the releases studied or evaluated
in this report. Exhibit 2-3 identifies the number of cases by industry.
Exhibit 2-3
Number of Case Studies by Industry (SIC)
Electric, Gas, & Sanitary Services (49)
Paper & Allied Products (26)
Chemical & Allied Products (28)
Food & Kindred Products (20)
Primary Metal Industries (33)
Nonmetallic Minerals, Except Fuels (14)
Petroleum & Coal Products (29)
Fabricated Metal Products (34)
35 (31%)
27 (24%)
11 (10%)
10 (9%)
6 (5%)
4 (4%)
4 (4%)
3(3%)
Page 2-10
-------
Exhibit 2-3 (continued)
Number of Case Studies by Industry (SIC)
Transportation Equipment (37)
Agricultural Production - Livestock (02)
Electronic & Other Electric Equipment (36)
Stone, Clay, & Glass Products (32)
Apparel & Other Textile Products (23)
Instruments & Related Products (38)
Industrial Machinery & Equipment (35)
3 (3%)
2 (2%)
2 (2%)
2(2%)
1 (1%)
1 (1%)
1 (1%)
These findings are generally consistent with the Agency's previous finding that four industries, Paper
and Allied Products (SIC 26), Chemicals and Allied Products (SIC 28), Petroleum Refining & Related
Industries (SIC 29), and Primary Metal Industries (SIC 33), generated more than 68 percent of the 7.6
billion tons of Industrial D waste managed on-site in 1985.7 Although these case studies were
identified based on available data and other selection criteria, the number of cases identified per
industry and the volume of waste generated per industry appear to be positively correlated.
2.2.3 Number of Cases By Type of Waste Management Unit
Four major types of land-based treatment and storage units were identified in the case studies:
landfills, surface impoundments, land application units, and waste piles. Exhibit 2-4 presents the
number of case studies by waste management unit. Several cases studies discuss more than one unit,
therefore, the total number of units is higher than the total number of case studies. Approximately.93
percent of the case studies involved landfills and/or surface impoundments. This finding may partly
reflect the greater regulatory attention these units receive from the states, rather than necessarily imply
that these units have more frequent releases than other types of waste management units. Over 90
percent of the landfills and 80 percent of the surface impoundments included in the case studies are
unlined and over 70 percent of the units are no longer being used to manage non-hazardous industrial
wastes.
All 50 states have developed regulations for surface impoundments. Approximately 90, 46,
and 18 percent of the states have developed regulations specifically for landfills, land application units,
and waste piles; respectively.8 The large number of surface impoundments identified in this report is
consistent with a finding of EPA's 1987 Telephone Screening Survey that slightly more than half of
the facilities that generate and manage on-site non-hazardous industrial waste managed their wastes in
7 U.S. Environmental Protection Agency, Office of Solid Waste, "Non-Hazardous Waste Management: Priority
Industries," draft, July 1993.
8 U.S. Environmental Protection Agency, Office of Solid Waste, "State Requirements for Non-Hazardous
Industrial Waste Management Facilities, September 1995.
Page 2-11
-------
Exhibit 2-4
Number of Case Studies By Waste Management Unit
Landfill
Surface Impoundment
Land Application Unit
Waste Pile
73
31
12
4
on-site surface impoundments. The 1987 survey also indicated that 35 percent of the facilities
managed their wastes on-site in waste piles, 19 percent in landfills, and 18 percent in land application
units.
Many states apply their non-hazardous industrial waste regulations on a site-by-site basis and,
therefore, not all facilities in a state are subject to the same data collection and recordkeeping
requirements. One recent report indicates that even states with waste pile regulations do not appear to
be actively enforcing control, monitoring, and closure requirements, which may partly explain the
small number of release descriptions for waste piles.9
The large number of landfills and surface impoundments in the release descriptions appears
consistent with the type of management units used by the primary industries included in this report.
Reportedly, the food processing industry has the largest number of non-hazardous industrial waste
surface impoundments and land application units.10**1 Other major industries identified in this
report with a large number of surface impoundments and landfills include the paper, electric power,
chemical, mining, and metal finishing industries.
2.2.4 Type of Media Affected
Nearly 98 percent of the case studies involved groundwater contamination. Approximately 31
percent of the case studies involved contamination of surface water or soil. No case studies had
documented damages from releases to the air and nearly 30 percent of the case studies affected
multiple media.
The predominance of groundwater contamination is consistent with the use of groundwater
monitoring as the most common method of detecting releases from waste management units. Surface
water is not as routinely monitored as groundwater. Surface water sampling is seldom conducted at a
9 "State Regulation of Waste Piles, El Digest Industrial and Hazardous Waste Management," April 1996, cages
16 to 21.
10
"Nonhazardous Industrial Surface Impoundments: State Regulations and the Environmental Marketplace,"
Environmental Information, Ltd., 1996, pages 3 to 7.
11 "State Requirements for Nonhazardous Waste Land Application Units, El Digest Industrial and Hazardous
Waste Management," May 1996.
Page 2-12
-------
facility until a release is identified. Soil sampling is conducted much less frequently than groundwater
monitoring, and like surface water sampling, is seldom conducted until a release has been identified.
Few states regulate air emissions from non-hazardous industrial waste management units. Thus, it is
not surprising that no cases of damage from releases to the air were documented in the case studies
collected for this report.
2.2.5 Types of Contaminants Released
The number of and types of contaminants routinely analyzed for in groundwater and other
types of samples varies among states and facilities. Although most facilities included in the case
studies were monitored for a wide range of constituents, the 20 constituents most commonly detected
to exceed regulatory levels were inorganics. Approximately 50 constituents were detected three or
more tunes, and 70 constituents were detected fewer than three times. Exhibit 2-5 identifies all of the
TC constituents that were detected in the case studies, Exhibit 2-6 presents all of the constituents with
SMCLs that were identified in the case studies, and Exhibit 2-7 identifies the other constituents that
were detected in at least three case studies. The exhibits also identify the number of cases where each
constituent was detected, the number of times the constituent was detected above at least one
regulatory level, the regulatory levels, the average maximum and the highest maximum detected
concentration identified in the case studies, and the range of the ratio -of the highest detected
constituent concentrations to regulatory standards. Note, only constituents with regulatory standards
are included hi Exhibits 2-5, 2-6, and 2-7.
Many inorganic constituents were elevated in groundwater monitoring wells. Constituents that
exceeded state groundwater protection standards or federal drinking water standards most frequently
were:
Iron (49 detections)
Chloride (32 detections)
Manganese (34 detections)
Sulfate (29 detections)
Lead (22 detections)
Chromium (21 detections)
Cadmium (17 detections)
Benzene (16 detections)
Arsenic (15 detections)
Zinc (13 detections)
Aluminum (12 detections)
Nitrate (12 detections)
Six of the constituents identified above (iron, chloride, manganese, sulfate, zinc, and aluminum) have
drinking water standards that are based only on SMCLs.
A total of 25 TC constituents have been detected in the release descriptions. Exhibit 2-5
identifies 20 of the 25 TC constituents detected. Five TC constituents (2,4,6-trichlorophenol, 2,4-
dinitrotoluene, o-cresol, p-cresol, and methyl ethyl ketone) were not included hi Exhibit 2-5 because
there were no federal or state standards established for them. All but 2 of the 20 TC constituents
identified in Exhibit 2-5 (carbon tetrachloride, 1,4-dichlorobenzene) were detected above a federal or
state standard. The majority (85 percent) of the TC constituents detected above a federal or state
standard exceeded the standards by at least 1 time, 60 percent exceeded by 10 times, 50 percent
exceeded by 100 times, 20 percent exceeded by 1,000 times, 10 percent exceeded by 10,000 tunes,
and none exceeded by at least 100,000 times. The average maximum detected concentrations for five
of the TC constituents (arsenic, benzene, selenium, vinyl chloride, and lindane) exceeded the TC
Page 2-13
-------
Exhibit 2-5
TC Contaminants Detected in Case Studies
*
Constituent
Lead
Chromium
Arsenic
Cadmium
Barium
Benzene
Mercury
Selenium
Trichloroethylene
Vinyl chloride
Silver
Chlorobenzene
Chloroform
Tetrachloroethylene
1,4-
Dichlorobenzene
Carbon
tetrachloride
Pentachlorophenol
Lindane
1 ,2-Dichloroethane
Heptachlor
TC Level
(mg/1)
5
5
5
1
100
0.5
0.2
1
0.5
0.2
5
100
6
0.7
7.5
0.5
100
0.4
0.5
0.008
Case Studies
With
Detected
' Constituents
37
36
. 29
28
28
23
19
18
15
13
12
9
8
7
5
4
2
2
2
1
Case Studies with
Detected
Concentrations
Above Federal/
State Standards
22
. 21
15
17
11
16
6
6
7
6
3
2
2
3
0
0
2
2
2
1
Range of
Federal/State
Standards
(mg/1)
0.0015 - 0.05
0.01 - 0.1
0.005 - 0.05
0.0004 - 0.005
0.2-2
0.0005 - 0.001
0.0002 - 0.002
0.01 - 0.05
0.0005 - 0.005
0.0002 - 0.002
0.01 - 0.1
0.05
0.0006 - 0.08
0.005
0.015 - 0.075
0.005
0.001
0.0002
0.005
0.0004
Average
Maximum
Detected
Concentration
(mg/1)
1.3
2.3
28.4
0.2
31.1
1.4
0.002
2.2
0.03
2.9
0.006
0.025
0.11
0.0085
0.017
0.0017
0.036
0.66
0.016
0.002
Highest
Maximum
Detected
Concentration
(mg/1)
28
58
595
3 .
630
15
0.007
27
0.14
8.6
0.01
0.05
0.4
0.026
0.035
0.004
0.063
1.2
0.02
0.002
Ratio of Highest
Detected
Concentration
to Federal/State
Standards
560- 18,667
580 - 5,800
11,900- 119,000
600 - 7,500
315 - 3,150
15,000 - 30,000
3.5 - 35
540 - 2,700
28 - 280
4,300 - 43,000
0.1 - 1
1
105 - 667
5
0.5 - 2.3
0.8
63
6,000
4
5
Page 2-14
-------
Exhibit 2-6
Contaminants with SMCLs Detected in Case Studies
Constituent/
Property
pH
Iron
Chloride
Sulfate
Total dissolved
solids
Manganese
Zinc
Copper
Aluminum
Fluorides
Case Studies
With Detected
Constituents
66
54
52
50
48
39
33
17
12
12
Case Studies with
Detected
Concentrations
Above
Federal/State
Standards
24
49
32
29
30
34
13
2
12
4
Range of
Federal/State
Standards
(mg/1)
6.5 - 8.5
(unitless)
0.15 - 0.3
125 - 250
125 - 500
500 - 1,000
0.0025 - 0.3
0.05 - 5
0.13- 1.3
0.05 - 0.2
0.44 - 4
Average
Maximum
Detected
Concentration
(mg/1)
5.4
(unitless)
244
1,825
2,273
7,033
10
20
0.15
235
12
Highest
Maximum
Detected
Concentration
(mg/1)
12.4
(unitless)
4,400
37,200
26,000
98,164
97
262
0.9
1,933
98
Ratio of the
Highest Detected
Concentration to
Federal/State
Standards
1.5 - 1.9
14,667 - 29,333
149 - 297
52 - 208
98 - 196
323 - 3,880
52 - 5,240
0.7-7
9,665 - 38,660
25 - 223
Page 2-15
-------
Exhibit 2-7
Other Contaminants Detected in At Least Three Case Studies
Constituent
Sodium
Nitrate
Magnesium
Toluene
Phenol
Ammonia
Nickel
Nitrite
Xylenes
1 , 1 -Dichloroethane
Nitrogen
Dichloromethane
Ethylbenzene
Vanadium
Dichloroethylene
~5 IF~
Beryllium
Cyanide
f, i ..
Cobalt
Naphthalene
Antimony
trans- 1,2-
Dichioroethyiene
Thallium
Case Studies
With Detected
Constituents
40
33
32
20
18
16
14
11
10
10
8
7
7
1 7
7
7
6
6
5
5
5
.
.
Case Studies with
Detected
Concentrations
Above
Federal/State
Standards
8
12
3
7
10
2
4
9
1
0
1
0
4
3
0
3
6
£*
1
0
1
4
2
Range of
Federal/State
Standards
(mg/1)
20 -160
2- 10
35 - 420
0.07 - 1
0.001 - 1.2
2
0.08 - 0.1
1
0.124 - 10
0.7
0.7
2- 10
0.005 - 0.015
0.14 - 0.7
0.014
0.07
0.004- 1.1
0.04 - 0.2
2.9
0.005
0.008
0.006
0.01
0.002
Average
Maximum
Detected
Concentration
(mg/1)
1,292
46
140
0.62
6.3
55.3
0.1
18.9
2
0.18
1.4
8.1
0.6
0.3
0.1
0.081
0.25
0.09
40.4
0.083
3.3
0.67
0.0016
0.0048
Highest
Maximum
Detected
Concentration
(mg/1)
15,600
560
1,495
6.7
60
410
0.5
64
4.8
1
10.6
57.6
4
0.9
0.4
0.24
1.7
0.4
82
0.16
14.2
3
0.052
0.01
Ratio of the
Highest Detected
Concentration to
Federal/State
Standards
98 - 780
56 - 280
4-43
7-96
50 - 60,000
205
5 - 6.3
64
0.5 - 39
1
15
6-29
267 - 800
1.3 - 6.4
31
3
2-425
2- 10
28
32
1,775
500
5
5
Page 2-16
-------
regulatory levels established for these constituents and the highest maximum detected concentrations
for over half of the identified TC constituents exceed TC regulatory levels.
All SMCLs or similar state standards, except those for foaming agents, color, odor, and
corrosivity, were violated by one or more release descriptions. As shown in Exhibit 2-6, the majority
(90 percent) of the SMCL constituents exceeded the standards by at least 1 time, 80 percent exceeded
by 10 times, 40 percent exceeded by 100 times, 20 percent exceeded by 1,000 times, 10 percent
exceeded by 10,000 times, and none exceeded by at least 100,000 times. (Because silver has both a
TC level and an SMCL, it is included in Exhibit 2-5 with the other TC constituents.) SMCLs are
based on aesthetic considerations (e.g., taste and odor) and are not federally enforceable. Therefore,
exceedences of the SMCLs do not necessarily indicate a potential danger to human health or the
environment. Sixteen of the case studies (14 percent) were identified based only on an exceedence of
an SMCL. This type of contamination is discussed further in Chapter 5.
Exhibit 2-7 identifies 24 other constituents that were detected in the release descriptions. All
but four of the constituents in Exhibit 2-7 (1,1-dichloroethane, nitrogen, vanadium, and cobalt) were
detected above a federal or state regulatory level. Half (50 percent) of these other constituents
exceeded one of the standards by at least 10 times, 13 percent exceeded by 100 times, 4 percent
exceeded by 1,000 times, and none exceeded by at least 10,000 times.
Constituents managed in landfills were detected in samples nearly three times more frequently
than constituents managed in surface impoundments. All of the constituents presented in Exhibits 2-5,
2-6, and 2-7 are associated with wastes managed in landfills. Approximately 81 percent of the
constituents are associated with both landfills and surface impoundments, 33 percent are associated
with landfills, surface impoundments, and land application units, 33 percent are associated with
landfills, surface impoundments, and waste piles, and 12 percent are associated with all 4 waste
management units. The constituents that are associated only with landfills are antimony, beryllium,
boron, cobalt, cyanides, silver, and thallium.
Exhibit 2-8 identifies the 10 constituents for each of the 6 industries that were identified most
frequently in the case studies. As the exhibit illustrates, inorganics are the most commonly detected
chemicals. The commonly detected constituents are chloride, pH, iron, lead, total dissolved solids,
manganese, sulfate, magnesium, zinc, and arsenic.
2.3 Major Limitations
The findings presented in this chapter must be interpreted with care for several reasons,
including the limited time available to collect data, potentially unrepresentative data, and the Agency's
stringent release selection criteria. Each of these major limitations is discussed in detail below.
Data were collected under significant time constraints. The significant amount of data
included in this chapter were collected and analyzed over a four-month period. During this time the
Agency reviewed previously collected data, readily available databases, and reports; identified and
contacted appropriate state and federal personnel; visited state and EPA Regional offices; reviewed
facility files; prepared case study summaries; developed a database to analyze the data; performed
QA/QC on the data; sent draft case studies to states and facilities for review; prepared a draft report
for public review; and incorporated comments into the report, as appropriate. Due to the time
constraints of the consent decree, the Agency had to carefully prioritize its efforts and, in doing so,
Page 2-17
-------
Exhibit 2-8
Most Common Constituents By Industry
Industrial Classification
Code (SIC)
Refuse Systems (495)
Paper & Allied Products
(26)
Chemical & Allied Products
(28)
Constituent
PH*
Iron*
Manganese
Sulfate*
Lead
Chloride*
Magnesium
Nitrate
Total dissolved solids*
Trichloroethylene
PH*
Chloride
Iron*
Sulfate*
Sodium
Calcium carbonate
Calcium
Magnesium
Zinc
Total dissolved solids*
Benzene
Chromium
Iron*
Lead
Manganese*
Sulfate*
Number of Case Studies in Which
the Constituent Was Detected
19
14
13
13
12
11
10
10
10
10
22
21
21
20
15
12
11
11
11
10
7
7
7
6
6
6
Page 2-18
-------
Exhibit 2-8 (continued)
Most Common Constituents By Industry
Industrial Classification
Code (SIC)
Chemical & Allied Products
(28) (Cont.)
Food & Kindred Products
(20)
Non-Metallic Minerals,
Except Fuels (14)
Constituent
Total. dissolved solids*
Zinc
Arsenic
Chloride
Nitrite
Nitrate
Nitrogen
PH*
Total dissolved solids*
Total filterable residue
Calcium
Chloride*
Magnesium
Sodium
Arsenic
Iron*
Lead
Manganese
PH*
Cadmium
Chloride*
Copper
Nickel
Potassium
Number of Case Studies in Which
the Constituent Was Detected
6
6
5
5
6
5
5
4
4
4
3"
3
3
3
4
4
4
4
4
3
3
3
3
3
Page 2-19
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Exhibit 2-8 (continued)
Most Common Constituents By Industry
Industrial Classification
Code (SIC)
Primary Metal Industries
(33)
Constituent
Lead.
Chromium
Aluminum
Arsenic
Barium
Cadmium
Chloride
Mercury
Nickel
Zinc
Number of Case Studies in Which
the Constituent Was Detected
4
3
2
2
2
2
2
2
2
2
Constituents with Secondary Maximum Contaminants.
may have eliminated or missed a number of potential case studies that could have been included in the
report if additional data were available and/or additional time was spent collecting and reviewing data.
Data may be unrepresentative and/or out-of-date. In this report, the Agency did not attempt to
estimate the proportion of non-hazardous management facilities currently experiencing constituent
releases. Due primarily to the limited time available for data collection and analysis, the Agency
relied upon readily available data. The Agency did not perform any new sampling or collect new data
from facilities managing non-hazardous industrial wastes. Nor did the Agency perform a
comprehensive review of previously collected state and federal data for all non-hazardous industrial
waste management facilities. State file reviews were conducted in one to three days per state and were
limited to those states that indicated having files of release incidents that met the Agency's selection
criteria. Although the collection of release descriptions is not statistically representative in any way,
these cases are indicative of the type of releases associated with the management of non-hazardous
industrial waste.
Because only readily available data were analyzed, the data may not reflect current waste
generation and management practices at the particular facility. Environmental contamination resulting
from waste disposal practices may take many years to become evident; some releases described in this
report occurred over 20 years ago. The documented releases may have resulted from particular waste
generation and disposal practices or other conditions that no longer exist. Specifically, process
feedstocks, processing operations, waste characteristics, and/or waste management practices may have
changed. Facilities may no longer manage their wastes in unlined units or in environmentally sensitive
Page 2-20
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areas. Therefore, releases associated with a waste do not necessarily demonstrate that current waste
management practices or regulations need to change. Conversely, the 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, however, believes that information on dangers posed by past waste
management practices is useful in demonstrating the potential for human health or environmental
damages.
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 also severely
limited by variations in recordkeeping, monitoring, and other state requirements. Recordkeeping and
monitoring procedures vary significantly among the states. Several states have complete and up-to-
date central enforcement or monitoring records on facilities that generate and manage non-hazardous
industrial wastes. Where states have such records, information on releases may be readily available.
Thus, states with the most complete and accessible monitoring information on non-hazardous industrial
wastes may appear to have more releases than states with less centralized information management
programs.
Stringent selection criteria. The Agency developed stringent selection criteria to help focus its
data collection efforts and to avoid any misrepresentation of release incidents. By focusing solely on
releases clearly associated with non-hazardous industrial waste management units, the Agency
excluded numerous release incidents caused by accidental releases and spills of products. Although
these incidents may have been caused by hazardous constituents similar to those managed hi non-
hazardous industrial waste management units, and may pose similar hazards, the Agency did not
analyze these cases, largely because of the inability of RCRA to prevent product releases.
The Agency also excluded release incidents that could not be linked to specific facilities.
Thus, cases of groundwater and surface water contamination caused by multiple facilities were
excluded because the source of the releases could not be associated with specific facilities or waste
management units.
The Agency also excluded numerous release incidents associated with facilities that manage
hazardous, municipal, or special wastes in addition to non-hazardous industrial waste. Facilities that
manage hazardous, municipal, or special wastes frequently co-dispose of their non-hazardous industrial
wastes in the same or adjacent waste management units. Due to the close proximity of these different
units, sampling results generally cannot identify the specific unit associated with the release. Thus, the
Agency excluded cases where non-hazardous industrial waste was managed in the same or adjacent
waste management units as hazardous, municipal, or special wastes, because the source of the release
could not clearly be associated with the non-hazardous industrial waste.
Page 2-21
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CHAPTERS. POTENTIAL GAPS ASSOCIATED WITH
HAZARDOUS WASTE CHARACTERISTICS DEFINITIONS
This chapter examines how well the existing hazardous waste characteristics address the types
of risk they were intended to address, that is, their target risks. It also addresses certain other or non-
target risks that are closely associated with the definitions of the hazardous characteristics. This
evaluation of potential gaps begins by examining the characteristics' definitions and test methods.
This approach is used for two reasons. First, limitations in the characteristics' effectiveness in
reducing their target risks may themselves constitute important potential gaps. When the
characteristics were promulgated, the Agency identified physical hazards and acute toxic hazards
during transport and disposal activities, along with chronic exposure to groundwater contaminated with
specific waste constituents, as being among the most important waste management risks. Reducing
these risks remains an important goal of the characteristics. Second, this analysis lays the groundwork
for evaluating other potential gaps. Specifically, risk-based screening methods are used to evaluate
non-target risks from non-ground-water pathways associated with the toxicity characteristic (TC)
analytes. The findings of that analyses are used to identify potential gaps associated with a wider
universe of known and possible non-hazardous industrial waste constituents, as discussed in Chapter 4.
This chapter revisits many of the assumptions and approaches used to develop the existing
hazardous waste characteristics. The ignitability, corrosivity, and reactivity (ICR) characteristics are
essentially unchanged since their initial promulgation in 1980. The TC characteristic was revised in
1990, but has not changed materially since then. Potential gaps in these characteristics may be
identified if the state of knowledge about risks addressed by the characteristics has improved since the
characteristics were promulgated; risks that were not specifically addressed may now be identified as
more important, such as risks from releases to surface water, inhalation, and indirect pathways and
ecological risks. In addition, the tests used to identify wastes with hazardous characteristics do not
reliably identify all of the risks the characteristics were intended to address.
The following sections address these issues. Section 3.1 reviews the statutory and regulatory
language related to the types of risks the hazardous waste characteristics were intended to address and
discusses the major categories of waste management risks addressed and not addressed by the current
characteristics. Sections 3.2 through 3.4 discuss potential gaps associated with the ignitability,
corrosivity, and reactivity characteristics, respectively. In addition, a detailed comparison of the ICR
characteristics can be found in Appendix C. Section 3.5 discusses the potential gaps associated with
the toxicity characteristic, including updated risk information on the TC analytes. Section 3.6
evaluates the toxicity characteristic leaching procedure (TCLP) as a predictor of constituent releases
and potential risk.
3.1 Types of Risks Addressed by RCRA Hazardous Waste Characteristics
3.1.1 Statutory and Regulatory Framework
The RCRA hazardous waste characteristics are a vital part of the comprehensive program of
hazardous waste management established by Subtitle C of RCRA, as amended. Three provisions of
the RCRA statute are particularly relevant to identifying and expanding the hazardous waste
characteristics (and listing hazardous wastes).
Page 3-1
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First, Section 1004(7) defines hazardous waste as "a solid waste, or
combination of solid wastes, which because of its quantity, concentration, or
physical, chemical, or infectious characteristics may (A) cause, or significantly
contribute to an increase in mortality or an increase in serious irreversible, or
incapacitating reversible, illness; or (B) pose a substantial present or potential
hazard to human health or the environment when improperly treated, stored,
transported, or disposed of, or otherwise managed." This definition indicates
the general types of risks that the hazardous waste management regulations are
meant to address.
Second, Section 3001 (a) requires EPA to "develop and promulgate criteria for
identifying the characteristics of hazardous waste, and for listing hazardous
wastes,... taking into account toxicity, persistence, and degradability in
nature, potential for accumulation in tissue, and other related factors such as
flammability, corrosiveness, and other hazardous characteristics. Such criteria
shall be revised from time to time as may be appropriate."
Third, Section 3001 (b) requires EPA to "promulgate regulations identifying the
characteristics of hazardous waste, and listing particular hazardous wastes,...
which shall be based on the criteria promulgated under [Section 3001 (a)] and
shall be revised from time to time thereafter as may be appropriate." The
Section also requires EPA to "identify or list those hazardous wastes which
shall be subject to the [hazardous waste regulations] solely because of the
presence in such wastes of certain constituents (such as identified carcinogens,
mutagens, or teratogens) at levels in excess of levels which endanger human
health."
In response to the mandate of Section 3001 (a), EPA promulgated two sets of criteria for
identifying the characteristics of hazardous waste in 40 CFR 26L10(a). The first set of criteria reflects
the statutory definition of hazardous waste and the types of risks that the characteristics are intended to
address:
"(1) The solid waste may
(i) cause, or significantly contribute to, an increase in mortality or an increase
in serious irreversible, or incapacitating reversible, illness; or
(ii) pose a substantial present or potential hazard to human health or the
-environment when it is improperly treated, stored, transported, disposed, or
otherwise managed."
The second set of criteria considers implementation factors:
"(2) The characteristic can be
(i) measured by an available standardized test method which is reasonably
within the capability of generators of solid waste or private sector laboratories
that are available to serve generators of solid waste; or
Page 3-2
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(ii) reasonably detected by generators of solid waste through their knowledge
of their waste."
As stated in the May 19, 1980, final rule, EPA adopted the second set of criteria because the primary
responsibility for determining whether wastes exhibit a characteristic rests with generators, for whom
standard and available testing protocols are essential.1 This Scoping Study addresses these criteria for
the current characteristics in only a general way. The Agency, however, will carefully consider these
factors when deciding the appropriate course of action for addressing any potential gaps in coverage
that are identified in this Study.
The following sections review the nature of the risks to human health and environment
potentially posed by non-hazardous industrial waste management. These risks are associated with
physical hazards, acute toxic hazards to humans, chronic toxic hazards to humans, risk to non-human
receptors, and other hazards. In the discussion below, risks addressed by the hazardous waste
characteristics are distinguished from those risks not directly or adequately addressed. The purpose of
this section is to develop a preliminary list of possible gaps in the characteristics. At this stage, few
judgments are made as to the nature and severity of any potential gaps. Instead, the remainder of this
Report investigates these potential gaps.
3.1.2 Risks Associated with Physical Hazards
Physical hazards include agents that cause direct physical harm such as thermal burns, wounds,
contusions, or eye injuries, in contrast to agents causing harm through chemical bums or toxic effects.
These hazards are controlled primarily through the ignitability, corrosivity, and reactivity (ICR)
characteristics. EPA patterned these characteristics after similar regulations promulgated by the U.S.
Department of Transportation, the National Fire Protection Association, and other organizations.
The ICR characteristics are intended primarily to protect waste management and transportation
workers against hazards often associated with hazardous materials. These hazards include
fiammability, explosivity, and the propensity to react violently with other wastes, corrode containers,
and directly injure skin and eyes during transport or management activities. In addition, these
characteristics are intended to prevent the facilitated release and transport of hazardous waste
constituents. For example, the corrosivity test is designed, in part, to identify wastes that, because of
their acidity or basicity, may facilitate the solubilization of metals from wastes. This solubilization
increases the potential impact of metals in groundwater, thereby increasing the likelihood of risks to
human health via contaminated groundwater.
For the purposes of this Scoping Study, the question is: What physical risks may arise from
the management of non-hazardous industrial wastes that are currently not covered by the
characteristics? Several potentially significant physical risks are not effectively addressed by the
hazardous characteristics. Some of the potential gaps arise from specific definitions of the ICR
characteristics. These potential gaps, which are discussed in more detail in Sections 3.2 through 3.4,
include:
The lack of coverage of corrosive solids;
The decision not to address liquids with moderate flash points;
1 45 Federal Register 33108-33110, May 19, 1980.
Page 3-3
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Limitations in the test procedures prescribed for reactivity; and
Potential limitations of pH as an adequate indicator of corrosivity.
These issues relate to protecting waste management and transportation workers from physical injuries,
except where explosions or fire might release toxic particulates that could harm nearby residents.
Physical hazards to residents near management facilities are not considered, based on the assumption
that the general public has limited access to non-hazardous industrial waste management facilities.
Other physical concerns relate to facilitated pollutant transport. For example, the corrosivity
characteristic was not intended to address corrosion to liners or any materials other than steel or to
prevent facilitated transport of organic chemicals through solubilization in discarded solvents. EPA
considered, and decided to omit, a "solvent override" provision in the 1990 TC rule that would have
classified as hazardous wastes with more than a specified concentration of hazardous organic solvents.
The Agency, however, left open the possibility that such a provision could be reconsidered if
additional data warrant it.2 A related issue is the potential formation of dense and light non-aqueous
phase liquids (DNAPLs and LNAPLs). They are a potential concern both because they may facilitate
pollutant transport and they have the potential for damaging groundwater resources and generating
high remediation costs. Section 4.4 discusses the issue of DNAPL and LNAPL formation.
3.1.3 Acute Toxic Hazards to Humans
The hazardous waste characteristics address some potential health risks from acute exposures
to toxic chemicals. They limit the potential for release of toxic chemicals during transportation,
storage, treatment, and disposal and resulting from fires, explosions, or violent reactions. There are no
specific quantitative benchmarks that define acceptable acute exposure limits, however. The main
focus of the ICR characteristics is on protecting workers, although the general public is implicitly
protected under the assumption that protecting on-site workers would protect more distant resident
populations as well. Sections 3.2 through 3.4 discuss potential gaps in the ICR characteristics.
The characteristics were not intended to protect against other acute systemic toxicity hazards.
Direct contact with a waste, in theory, could result in the absorption of an acutely toxic dose of a
waste constituent from a non-corrosive waste. The Agency, however, considered this scenario to be
highly improbable for non-hazardous industrial waste mismanagement. Similarly, acute exposures via
contaminated surface or groundwater are possible, but were considered much less likely to be
important than chronic toxicity under most circumstances. Because the TC focuses on the
groundwater pathway, with the attendant long-term transport and dilution of pollutants, EPA assumed
that chronic exposures would be dominant in determining the potential for adverse health effects.
Section 3.5.6 discusses the potential for acute adverse effects of exposure to the TC analytes and
Section 4.6 addresses acute risks from non-TC constituents.
3.1.4 Chronic Toxicity Risks to Humans
As noted above, EPA intended the TC to be the major vehicle for controlling chronic health
risks, although the reactivity and corrosivity characteristics also were intended to prevent releases that
facilitate exposure to waste constituents. Although RCRA Section 3001 identifies a range of types of
toxic effects of concern (toxicity, carcinogenicity, mutagenicity, and teratogenicity), the
implementation of the TC is limited to 40 chemicals for which toxicity and groundwater fate and
55 Federal Register 11809, March 29, 1990.
Page 3-4
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transport data were available when the Agency revised the characteristic in 1990. In addition, the
levels of protectiveness achieved by the TC leachate concentration standards were determined using
fate and transport models and assumptions that were current at the time. To the extent that the
toxicity data and groundwater fate and transport models have changed or improved in the six years
since the TC was promulgated, its expected level of protectiveness may also have changed. Section
3.5 discusses in detail potential gaps associated with the level of protectiveness of the TC in light of
recent advances in toxicology and groundwater modeling.
The TC was not intended to address several potentially important risks. These risks have been
identified as significant contributors to risks from some hazardous waste constituents and management
technologies, and might apply to non-hazardous industrial waste management as well. Probably the
most important risks potentially not directly addressed by the TC are associated with exposure
pathways other than groundwater. The TC did not attempt to address these risks because groundwater
was thought to be the dominant risk pathway for waste management. Upon re-examining potential
non-hazardous industrial waste management and mismanagement scenarios, however, EPA recognizes
that other pathways also may be important.
One pathway not directly addressed by the TC is the direct inhalation of volatile or particulate-
bound waste constituents to air from waste management units during normal operation or after closure.
Such exposures to on-site workers and off-site receptors through direct inhalation may be significant
for some constituents. Other potentially important pathways include the surface water pathway and
"indirect" pathways arising from air releases (e.g., air deposition to crops), runoff, and the discharge of
contaminated groundwater to surface water. Also, bioaccumulation of certain contaminants in aquatic
and/or terrestrial food chains could result in human exposures through the consumption of
contaminated fish, shellfish, livestock, and game animals. In Section 3.5, a screening-level risk
assessment and other information clarify the significance of these pathways for the TC analytes.
Chapter 4 extends the screening-level analysis to non-TC constituents.
3.1.5 Risks to Non-Human Receptors
Neither the TC nor the ICR characteristics were established specifically to reduce risks to non-
human receptors. Such risk reduction, to the extent that it occurs, is a byproduct of the control of
human health risks. For example, by preventing pollutant releases from fires and explosions or
reducing pollutant transport, the characteristics protect the environment as well as human health. The
quantitatively-defined levels of protection incorporated into the TC leachate concentration limits were
based on human toxicity considerations; they do not consider toxicity to non-human receptors. While
the exposure levels accepted as protective of human health may be generally protective of wildlife
populations, notable exceptions arise both from the ecotoxicological properties of some chemicals and
from differences between human and non-human receptor exposure patterns.
The question therefore can be asked: To what extent is the TC protective of ecological
receptors? As in the case of human health risks, the TC does not directly protect against risks from
chemicals not on the TC list. Similarly, it is not clear how protective the existing TC levels are for
the various exposure pathways that are most important for aquatic and terrestrial receptors. In the case
of ecological receptors, as is the case for human health, both direct and indirect exposure pathways
may be significant. These issues are addressed in more detail in Section 3.5 and Chapter 4 of this
report.
Page 3-5
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3.1.6 Other Risks Associated with Non-Hazardous Industrial Waste Management
In establishing the existing hazardous waste characteristics, the Agency focused exclusively on
human health risks directly associated with local effects of accidents and on chemical contamination of
the environment in the near vicinity of the management units. In Chapter 5 of this study, EPA has
taken a broader view, and has expanded the scope of the risk identification to include risks other than
those originally considered, even indirectly, in establishing the hazardous waste characteristics. These
additional categories of risks include damages to natural resources and contributions to large-scale
environmental problems.
Non-hazardous industrial waste management has the potential to adversely affect the value or
utility of natural resources, such as wetlands, groundwater, and air, without posing human health risks.
For example, releases from non-hazardous industrial waste management units have polluted previously
usable groundwater with constituents generally not considered toxic, such as iron, manganese, chloride,
and total dissolved solids. The regulatory criteria violated by these releases, such as Secondary
Maximum Concentration Levels (SMCLs) developed under the Safe Drinking Water Act, are not
directly health-related, but relate instead to the aesthetic properties or usability of the water.
Therefore, even though no health risk is predicted, the water is rendered unusable and the environment
is thereby damaged. Similarly, odor from non-hazardous industrial waste management may be seen as
an air resource damage, reducing the quality of life for affected individuals, even in the absence of
direct health effects.
The last category of risks are associated with the possible contribution of non-hazardous
industrial waste management to large-scale environmental problems, including:
Air deposition to the Great Waters;
Damages from airborne particulates;
Global climate change;
Potential damages from endocrine disrupters;
Red tides;
Stratospheric ozone depletion;
Tropospheric ozone and photochemical air pollution; and
Water pollution.
The possible relationship between non-hazardous industrial waste management and these risks is less
clear than for the previously identified risks.
As summarized in Exhibit 3-1, Section 3.1 has presented an intentionally broad inventory of
potential risks to human health and the environment associated with the management of non-hazardous
industrial wastes not currently identified as hazardous. This list provides a catalogue of risks for
evaluation against the existing characteristics in the rest of this chapter and the following chapters.
Page 3-6
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Exhibit 3-1. Risks Potentially Associated with Non-Hazardous Industrial Waste Management
Types of
Risks
Risks Intended to be
Addressed By
Characteristics
Risks Not Intended to be Addressed by Characteristics
Physical
Hazards
Burns and injuries to
waste management and
transportation workers
from fire, explosions,
and violent reactions
Skin, eye injury from
direct contact with
corrosive substances
(workers)
Facilitated transport of
chemicals (primarily
inorganics) in
groundwater
Physical injuries to the general public
Facilitated transport of organics from solubilization
DNAPL/LNAPL generation
Acute
Toxicity Risks
to Humans
Adverse effects from
inhalation of toxic
gases and particulates
(workers)
Inhalation of toxic gases and particulates by public
Acute health risks from other exposure pathways (direct
contact, ingestion of contaminated water or food)
Chronic
Toxicity Risks
to Humans
Risks of cancer and
non-cancer effects from
consumption of
groundwater
contaminated by TC
constituents (public)
Chronic health risks to workers
Chronic risks from exposures to non-TC chemicals (public
and workers)
Chronic risks associated with non-groundwater pathways:
inhalation of volatilized materials and particulates other
than those released from fire or explosion
ingestion of surface water contaminated by runoff or
groundwater discharge
risks to public from direct contact with waste,
contaminated soil, and in direct pathways (ingestion of
contaminated crops, fish, game)
Risks from specific types of toxins:
reproductive toxins
endocrine disrupters
Toxic Risks
to Nonhuman
Receptors
Aquatic toxicity
Toxicity to terrestrial organisms .
Sediment toxicity
Bioaccumulation/biomagnification
Groundwater exposure
Page 3-7
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Exhibit 3-1 (continued)
Types of
Risks
Risks Intended to be
Addressed By
Characteristics
Risks Not Intended to be Addressed by Characteristics
Other Risks
Damages to groundwater, surface water, and air affecting
their usability or quality
Non-hazardous industrial waste management contribution to
large-scale environmental problems, such as air deposition
to the Great Waters, damages from airborne particulates,
global climate change, potential damages from endocrine
disrupters, red tides, stratospheric ozone depletion,
tropospheric ozone and photochemical air pollution, and
water pollution.
3.2 Ignitability Characteristic
This section describes potential gaps related to the definition of the RCRA ignitability
characteristic and its test methods. The basic approach taken in identifying potential gaps for
ignitability as well as for corrosivity and reactivity was to review the original 1980 rulemaking record
and to compare the characteristic to approaches taken to controlling similar hazards under other
regulatory schemes, including the U.S. Department of Transportation's (DOT's) hazardous materials
regulations, the U.S. Occupational Safety and Health Administration's (OSHA's) worker health
hazards standards, and state hazardous waste management standards.
3.2.1 Definition of Ignitability
The ignitability characteristic is intended to "identify wastes capable of causing fires during
routine transportation, storage and disposal, and wastes capable of exacerbating a fire once started."
These risks include generally recognized fire hazards to waste management and transportation workers,
such as burns and inhalation smoke or fumes, and the potential generation and facilitated transport in
air of toxic particulates and fumes that could harm the general public. According to 40 CFR 261.21, a
solid waste exhibits the characteristic of ignitability if a representative sample of the waste has any of
the following properties:
Is a liquid, other than an aqueous solution containing less than 24 percent
alcohol by volume and has flash point less than 60°C (140°F), as determined
by:
- A Pensky-Martens Closed Cup Tester, using the test method specified
in ASTM Standard D-93-79 or D-93-80 (incorporated by reference, see
§ 260.11),
Page 3-8
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A Setaflash Closed Cup Tester, using the test method specified in
ASTM standard D-3278-78 (incorporated by reference, see § 260.11),
or
An equivalent test method approved by the Administrator under
procedures set forth in §§ 260.20 and 260.21;
Is not a liquid and is capable, under standard temperature and pressure, of
causing fire through friction, absorption of moisture or spontaneous chemical
changes and, when ignited, bums so vigorously and persistently that it creates
a hazard;
Is an ignitable compressed gas as defined in 49 CFR 173.300 and as
determined by the test methods described in that regulation or equivalent test
methods approved by the Administrator under §§ 260.20 and 260.21; or
Is an oxidizer as defined in 49 CFR 173.151.
3.2.2 Potential Gaps Related to Definition of Ignitability
Potential Ignitability Gaps
Excludes DOT Combustible Liquids (liquids
with flash point above 140 but below 200
degrees Fahrenheit)
Excludes Aqueous Flammable Liquids (alcohol
solutions of concentrations < 24 percent) that
are capable of flashing, but not supporting
combustion
References outdated DOT Regulations
No test methods for non-liquids
Liquids with flash point at or above
140°F not covered. The RCRA ignitability
characteristic includes liquid wastes with flash
point less than 60°C (140°F). When
promulgating the original characteristic, EPA
acknowledged choosing a definition for
ignitable liquid wastes that excluded some
potential wastes that would meet the definition
of hazardous materials under DOT regulations.
The DOT definition of flammable liquid
includes liquids with flash point not more than
60.5°C (141 °F), or any material in liquid phase
with a flash point at or above 37.8°C (100°F)
that is intentionally heated and offered for transportation or transported at or above its flash point in a
bulk packaging. The DOT definition of combustible liquid includes liquids with flash point above
60.5°C (141 °F) and below 93°C (200°F). Thus, the RCRA ignitability characteristic covers wastes
that would be classified as DOT flammable liquids, but not DOT combustible liquids. Consistent with
DOT regulations, OSHA includes such "combustible" liquids in its definition of health hazard, and
Rhode Island regulates them as hazardous wastes.
In a background document supporting the promulgation of the original characteristics, EPA
stated that the RCRA ignitability flash point limit of 140°F reflects conditions likely to be encountered
during routine waste management. In support of this conclusion, the Agency referenced seven studies
documenting temperatures and conditions at waste management units. The information available to the
Agency at the time was limited, however. Furthermore, two of these studies reported temperatures of
3 U.S. Environmental Protection Agency, Office of Solid Waste, Background Document: Resource
Conservation and Recovery Act. Subtitle C - Identification and Listing of Hazardous Wastes. Section 261.21-
Characteristics of Ignitabilitv. May 2, 1980, p. 10-11.
Page 3-9
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greater than 140°F. One study reported temperatures of approximately 160°F near the surface of a
landfill, noting that aerobic conditions near the surface of landfills often result in relatively high
temperatures.
Data are still limited regarding whether temperatures greater than 140°F are encountered
during non-hazardous industrial waste management, in what situations and how frequently this occurs,
and what maximum temperatures are reached (particularly in hotter regions of the nation). One
relevant issue is whether temperatures exceeding 140°F may be encountered during mismanagement
(as opposed to routine waste management). Examples of possible mismanagement scenarios for
ignitable wastes include:
Wastes stored in closed, heat-containing facilities (e.g., metal sheds, upper
floor warehouse spaces, or metal trucks) in hot climates and/or sunlight; and
Wastes mixed in waste management units in a manner that might generate heat
through chemical reactions, especially in the presence of hot climate or
sunlight.
No information is readily available regarding the universe of "combustible" industrial wastes
currently being managed as non-hazardous. Nevertheless, some liquid materials with flash points
generally in this range can be identified, as shown in Exhibit 3-2. Examples include certain alcohols,
low molecular weight esters, ethylene glycol ethers, kerosene, jet fuels, certain petroleum byproducts,
many "tints and paints," and individual chemicals including benzaldehyde, benzonitrile, and
bromobenzene. If these materials are disposed of or are present in wastes, the wastes may be
combustible, in spite of not being hazardous by the ignitability characteristic. In addition, mixtures of
materials of differing flash points may fall into this category.
Exclusion for aqueous liquids containing less than 24 percent alcohol may warrant
reexamination. At the time of the original rulemaking, some commenters argued that liquid wastes
such as wine and some latex paints that exhibit low flash points because of their alcohol content do
not sustain combustion because of the high percentage of water and therefore should not be designated
as characteristically hazardous waste. EPA agreed and excluded from the ignitability characteristic
aqueous solutions containing less than 24 percent of alcohol by volume. A similar exclusion is found
in DOT regulations. EPA stated that it hoped "to undertake further study to determine whether
another exclusion limit is more appropriate and to evaluate tests which might be capable of identifying
wastes which exhibit this phenomenon."4 EPA also intended to evaluate possible supplemental test
methods to evaluate flanunability hazards for these types of wastes.
The exclusion for aqueous liquids containing alcohol has caused confusion during
implementation and enforcement concerning whether it applies only to ethanol or more broadly to all
alcohols. The exclusion also focuses on aqueous alcohol solutions, rather than on the underlying
target of liquids with low flash points that do not sustain combustion. (Tests for sustained combustion
are now available: ASTM has methods D-4206 and D-4207.) In addition, the rationale that certain
liquids should not be considered ignitable if they do not sustain combustion may not be valid where an
excluded aqueous solution could flash and ignite a co-managed non-hazardous waste that would
sustain combustion.
' 45 Federal Register 33108.
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Exhibit 3-2
Materials Formerly Classified by DOT as Combustible Liquids
(which generally are not RCRA ignitable)
"Adhesive"
Alcoholic beverage
"Alcohol, n.o.s."
"Asphalt, cut back"
Benzaldehyde
Benzonitrile
Bromobenzene
Camphor oil
CEMENT (liquid)
"Chlordane, liquid"
Coal tar distillates
"Compound, cleaning, liquid"
"Compounds, tree or weed killing, liquid"
"Cosmetics, n.o.s."
"Crude oil, petroleum"
Decahydronaphthalene
Diacetone alcohol
Diesel fuel
Diisobutyl ketone
"Disinfectant, liquid, n.o.s."
"Driers, paint or varnish, liquid, n.o.s."
"Drugs, n.o.s."
Ethyl butyl acetate
Ethyl chloroacetate
Ethylene glycol monoethyl ether
("Cellosolve")
Ethylene glycol monoethyl ether acetate
("Cellosolve acetate")
Ethylene glycol monomethyl ether
("methyl Cellosolve")
Ethylene glycol monomethyl ether acetate
("methyl Cellosolve acetate")
Ethylhexaldehyde
Ethyl lactate
Ethyl silicate (tetraethyl orthosilicate)
Formaldehyde solution (flash point <= 141°F
in containers > 110 gal.)
Formaldehyde solution (flash point > 141°F
in containers > 110 gal.)
"Fuel, aviation, turbine engine"
Fuel oil
"Fuel oil (No. 1, 2, 4, 5, or 6)"
Furfural
"Gas drips, hydrocarbon"
Ink
"Insecticide, liquid, n.o.s."
Kerosene
"Mercaptan mixture, aliphatic (in containers
> 110 gal.)"
Methyl amyl ketone
Naphtha
"Oil, described as oil, Oil, n.o.s., Petroleum
oil"
Paint
Paint related material
Petroleum distillate
Petroleum naphtha
"Petroleum oil, n.o.s., See oil"
Pine oil
"Sodium methylate, alcohol mixture"
Turpentine
Source: Suspect Chemicals Handbook, 1988.
n.o.s. = not otherwise specified.
Note: Current DOT Hazardous Materials Table in 49 CFR 172.101 does not distinguish combustible liquids
from flammable liquids. The above list was taken from a 1987 version of DOT regulations that classified some
materials as combustible liquids. This list is intended to provide examples of materials "that may be combustible
(i.e., liquids with 141°F < flash point < 200°F)."
Page 3-11
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References to DOT regulations are outdated. The ignitability characteristic refers to a DOT
v definition of ignitable compressed gas (49 CFR 173.300) that has been withdrawn. Current DOT
regulations at 49 CFR 173.115 define flammable gas, which is any material that is a gas at 20°C
(68°F) or less and 101.3 kPa (kilopascals equal to 14.7 pounds per square inch) of pressure. The
complete definition includes any material that has a boiling point of 20°C (68°F) or less at 101.3 kPa
(14.7 psi)) that (1) is ignitable at 101.3 kPa (14.7 psi) when in a mixture of 13 percent or less by
volume with air; or (2) has a flammable range at 101.3 kPa (14.7 psi) with air of at least 12 percent
regardless of the lower limit. Likewise, the term oxidizer is no longer defined at 49 CFR 173.151. It
is now found at 49 CFR 173.127. These out-of-date citations constitute a potential gap because they
may cause regulatory confusion and misinterpretation and thereby may impede efficient and effective
compliance and enforcement.
3.23 Potential Gaps Related to Ignitability Test Methods
No test method is specified for non-liquids. The ignitability characteristic does not specify a
test method for non-liquid wastes. In a background document supporting the original rulemaking,
EPA stated that non-liquid wastes may present a hazard by virtue of their capacity to ignite and burn
as a result of friction, moisture absorption, or spontaneous reaction under the normal temperatures and
pressures encountered in waste management.5 The Agency noted that such wastes are akin to
reactive wastes and can directly injure workers or others as a result of fire, induced explosions, or
induced generation of toxic gases at almost any point in the waste management process'. Examples of
potential ignitable non-liquid wastes include soils highly contaminated with gasoline or other ignitable
substances and sorbents used to cleanup spills of ignitable substances.
In explaining the final rulemaking, the Agency stated that, although "EPA would have
preferred providing a test method for identifying ignitable solids, it has determined . . . that there are
no test methods capable of accurately identifying the small class of ignitable solids to which its
regulation is directed. EPA is presently working with the Department of Transportation and other
organizations to correct this deficiency."6 Since then, EPA has identified a test method that may be
suitable for identifying ignitable solids. Method 1030 ("Ignitability of Solids") has been proposed for
inclusion in the Third Edition of the EPA test methods manual "Test Methods for Evaluating Solid
Waste, Physical/Chemical Methods," EPA Publication SW-846.7 The method is appropriate for
pastes, granular materials, solids that can be cut into strips, and powdery substances.
33 Corrosivity
33.1 Definition of Corrosivity
According to 40 CFR 261.22, a solid waste exhibits the characteristic of corrosivity if a
representative sample of the waste has either of the following properties:
Is aqueous and has a pH less than or equal to 2 or greater than or equal to
. 12.5, as determined by a pH meter using Method 9040 in "Test Methods for
Background Document, supra footnote 2, p. 14.
6 45 Federal Register 33108.
7 60 Federal Register 37974, July 25,1995.
Page 3-12
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the Evaluation of Solid Waste, Physical/Chemical Methods," incorporated by
reference in § 260.11; or
Is a liquid and corrodes steel (SAE 1020) at a rate greater than 6.35 mm
(0.250 inch) per year at a test temperature of 55°C (130°F) as determined by
the test method specified in NACE (National Association of Corrosion
Engineers) Standard TM-01-69 as standardized in "Test Methods for the
Evaluation of Solid Waste, Physical/Chemical Methods," EPA Publication SW-
846, as incorporated by reference in § 260.11.
The first part of this definition encompasses wastes exhibiting low or high pH, which "can
cause harm to human tissue, promote the migration of toxic contaminants from other wastes, react
dangerously with other wastes, and harm aquatic life." Specifically, the Agency identified skin and
eye damage to transporters who are directly exposed to the waste as a primary focus of this
characteristic. The pH limits also were intended to address the potential solubilization of heavy metals
allowing migration to groundwater, reactions with incompatible wastes resulting in fires, explosions,
generation of flammable or toxic gases, generation of pressure inside vessels, and the dispersal of toxic
vapors, mists, and particulates.
The other part of the corrosivity characteristic relates to the corrosivity of waste to steel
containers. The Agency identified this aspect of corrosivity as a hazard because "wastes capable of
corroding metal can escape from the containers in which they are segregated and liberate other
wastes." The consequences of liberating wastes from containers during transportation or storage
include harm from direct contact, violent reactions, and the release of waste components to the
environment.
33.2 Potential Gaps Related to Definition of Corrosivity
Non-liquids are not,covered. The
current RCRA corrosivity characteristic is
limited to liquids. Other regulatory programs,
however, also cover corrosive non-liquids. For
example:
DOT regulates corrosive liquids
and solids as hazardous
materials;
-The OSHA definition of health
hazard includes all corrosives
regardless of physical form;
Potential Corrosivity Gaps
Excludes corrosive non-liquids
pH limits may not effectively protect against
some types of injury
Corrosion to materials other than steel is not
directly addressed
Solubilization of non-metals (e.g., by organic
solvents) is not addressed
Excludes irritants and sensitizers
pH test methods may not accurately predict
hazards
.The Basel Convention definitions of hazardous materials are not limited to
liquids; and
At least four states (California, New Hampshire, Rhode Island, and
Washington) include non-aqueous wastes in their definitions of corrosivity.
New Hampshire and Rhode Island specifically include corrosive gases as well
as corrosive solids.
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The states that include non-liquids in their corrosivity characteristics specify mixing the non-
aqueous waste with water and then testing for pH. The rationale for this approach is that the waste is
likely to come into contact with water during land-based management. In addition, EPA has
developed Method 9045 (Soil and Waste pH), which can be used to test some corrosive solid wastes.
Finally, Method 1120 (Dermal Corrosion) may be applied to solids, liquids, and emulsions (see
additional discussion below under "potential gaps related to corrosivity test methods").
pH limits may not cover some hazards. EPA originally proposed pH limits of 12.0 or greater
and 3.0 or less, and a majority of commenters argued that these limits were too stringent. The
commenters argued that the limit of 12.0 or greater would regulate as hazardous many lime-stabilized
wastes and sludges, thereby discouraging use of a valuable treatment technique, and that the pH limit
of 3.0 or less would regulate a number of substances generally thought to be innocuous (e.g., cola
drinks) and many industrial wastewaters prior to neutralization. EPA agreed with these commenters
and promulgated pH limits of 12.5 or greater and 2.0 or less in the 1980 final rule.
The more stringent proposed pH limits were based on studies of eye tissue damage. These
studies indicated that pH extremes above 11.5 and below 2.5 generally are not tolerated by human
comeal tissue.8 EPA decided that basing pH limits on eye tissue damage was unnecessarily
conservative. Thus, eye damage is a hazard not fully addressed by the corrosivity characteristic.
The corrosivity characteristic also was intended to prevent harm to ecological receptors caused
by the release of hazardous wastes with high- or low-pH. In discussing aquatic life in the original
background document,9 EPA noted that the optimum pH range for freshwater fish is 6.5 to 9.0 and
that an increase or decrease of 2 pH units beyond the optimum range causes severe effects. Levels of
pH of 11.0 or greater and 3.5 or less are fatal to all species of fish. EPA also noted that altering
surface water pH can reduce the productivity of food organisms essential to fish and wildlife. The pH
limits of the corrosivity characteristic (2.0 and 12.5) are well beyond the safe range for aquatic life,
but wastes presumably would be significantly diluted before the point of exposure to aquatic life.
EPA did not conduct a risk assessment of such potential hazards (e.g., modeling the pathway of waste
released to surface water and exposure to aquatic life) and thus it is not known under what
circumstances high- or low-pH wastes could cause harm to aquatic receptors.
Corrosion of materials other than steel is not directly addressed. In the second part of the
corrosivity characteristic, EPA uses steel corrosion as an indicator of corrosivity. EPA adopted this
aspect of corrosivity because "wastes capable of corroding metal can escape from the containers in
which they are segregated and liberate other wastes."10 EPA adopted DOT's corrosion standard,
noting that the rate at which a waste corrodes a material commonly used in container construction (low
carbon steel) is a suitable measure of its hazardousness.
8 U.S. Environmental Protection Agency, Office of Solid Waste, Background Document: Resource
Conservation and Recovery Act. Subtitle C-Identification and Listing of Hazardous Wastes. Section 261.22-
Characteristic of Corrosivitv. May 2, 1980, p. 5.
9 Id., pp. 9-10.
10 45 Federal Register 33109.
Page 3-14
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The reliance on the steel corrosion rate may create a potential gap if there are plausible
mismanagement scenarios where wastes are stored, transported, or disposed in containers made from
materials more easily corroded than low carbon steel (e.g., plastic by organic solvents) or are disposed
in solid waste management units lined with materials such as clay or synthetics. Also, there may be a
potential gap in the characteristic if waste management scenarios result in conditions where wastes are
subject to higher temperatures than the 130°F test temperature.
Solubilization of hazardous constituents. The corrosivity characteristic also was intended to
address the potential for high- and low-pH materials to solubilize potentially toxic waste constituents.
EPA offers the example that a drop in pH from 4.0 to 2.0 increases the solubility of red mercury oxide
or chromium hydroxide in water approximately 100 times.11 The general concern is for inorganic
ions that may be converted to more soluble species. This characteristic does not address the potential
solubilization of organic constituents by organic liquids such as solvents, nor does it address the
formation of non-aqueous phase liquids (NAPLs) by such materials. EPA considered including a
solvents "override" in the TC characteristic,12 but did not do so. The solvents override would have
caused wastes with high concentrations of solvents to be classified as hazardous on the basis of
potential NAPL formation. The issue of NAPL formation is discussed in more detail in Chapter 5.
Lack of coverage of sensitizers and irritants. At least two types of materials that may pose
potential hazards to humans through direct contact are not included in the corrosivity characteristic or
any other characteristic: irritants and sensitizers. OSHA includes irritants in its definition of health
hazard and defines irritant as a material that is not corrosive, but which causes a reversible
inflammatory effect on living tissue by chemical action at the site of contact. A chemical is a skin
irritant if, when tested on the intact skin of albino rabbits by the methods of 16 CFR 1500.41 for four
hours exposure or by other appropriate techniques, it results in an empirical score of five or more. A
chemical is an eye irritant if so determined under the procedure listed in 16 CFR 1500.42 or other
appropriate techniques. (See 29 CFR 1910.1200.)
OSHA also includes sensitizers in its definition of health hazard. A sensitizer is defined as a
material that causes a substantial proportion of exposed people or animals to develop an allergic
reaction in normal tissue after repeated exposure to the chemical. (See 29 CFR 1910.1200.)
This analysis did not identify any specific non-hazardous industrial wastes that are irritants or
sensitizers. Irritants and sensitizers, however, are common categories of materials and these properties
are often identified in laboratory testing of materials. A major issue regarding this potential gap is
whether any irritants and/or sensitizers pose a hazard in wastes that reaches the statutory level of
hazard intended to be covered by RCRA Subtitle C.
11 Ibid, p. 6.
12 55 Federal Register 11809, March 29, 1990.
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3.3.3 Potential Gaps Related to Corrosivity Test Methods
Use ofpH as an indicator has limitations. EPA chose pH as a measure of corrosivity
because "wastes exhibiting low or high pH can cause harm to human tissue, promote the migration of
toxic contaminants from other wastes, react dangerously with other wastes, and harm aquatic life."
The ability of some substances to damage human tissue, however, may not be adequately indicated by
a pH measurement. Other regulatory and advisory bodies (e.g., DOT, OSHA, Basel Convention) use
criteria based on full thickness destruction of human skin.
Since the original rulemaking in 1980, Method 1120 (Dermal Corrosion) has been developed
commercially. The dermal corrosion assay system is an in vitro test method which determines the
corrosive potential of a substance toward human skin. It can be used to test liquids (aqueous or non-
aqueous), solids (water soluble or insoluble), and emulsions. Method 1120 is essentially the same
method that DOT uses. It replaced previous tests (e.g., Draize test) that used live animals with a test
that uses a proprietary synthetic pig collagen material.
3.4 Reactivity
3.4.1 Definition of Reactivity
The reactivity characteristic is "intended to identify wastes, which because of their extreme
instability and tendency to react violently or explode, pose a problem at all stages of the waste
management process." This characteristic was intended to reduce physical risks to transportation and
disposal workers and to avoid incidents that could result in the release of toxic constituents into the air
consequent to an explosion or violent reaction. 40 CFR 261.23 states that a solid waste exhibits the
characteristic of reactivity if a representative sample of the waste has any of the following properties:
Is normally unstable and readily undergoes violent change without detonating;
Reacts violently with water;
Forms potentially explosive mixtures with water;
When mixed with water, generates toxic gases, vapor, or fumes hi a quantity
sufficient to present a danger to human health or the environment;
Is a cyanide or sulfide bearing waste which, when exposed to pH conditions
between 2 and 12.5 can generate toxic gases, vapors or fumes in a quantity
'sufficient to present a danger to human health or the environment;
Is capable of detonation or explosive reaction if it is subjected to a strong
initiating source or if heated under confinement;
13 45 Federal Register 33109.
Page 3-16
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Is readily capable of detonation or explosive decomposition or reaction at
standard temperature and pressure; or
Is a forbidden explosive as defined in 49 CFR 173.51, or a Class A explosive
as defined in 49 CFR 173.53 or a Class B explosive as defined in 49 CFR
173.88.
3.4.2 Potential Gaps Related to Definition of Reactivity
Potential Reactivity Gaps
Broad, non-specific definitions
References outdated DOT regulations
No test methods specified
The Definition is broad and lacks
specificity. In discussing the reactivity
characteristic in the 1980 final rule, EPA stated
that "the definition was intended to identify
wastes which, because of their extreme
instability and tendency to react violently or
explode, pose a problem at all stages of the
waste management process."14 EPA noted
that the reactivity characteristic encompasses a diverse class of physical properties and effects and
overlaps somewhat with the ignitability characteristic.
Some commenters argued that the definition was vague. They advocated using a quantitative
definition accompanied by testing protocol(s). EPA responded that "the prose definition should
provide generators with sufficient guidance to enable them to determine whether their wastes are
reactive."15 EPA argued that most generators whose wastes are dangerous because they are reactive
are well aware of this property and such wastes usually are generated from reactive feedstocks and/or
processes producing reactive products or intermediates. EPA further stated that problems posed by
reactivity appeared to be confined to a fairly narrow category of wastes.
Theoretically, the reactivity characteristic could be clarified and made consistent with other
programs (especially DOT) by developing more specific definitions of general terms such as "normally
unstable," "violent change," "potentially explosive," "reacts violently with water," "readily capable of
detonation," and so forth. Other programs include more specific definitions. For example, as shown
in Exhibit 3-3, DOT has adopted definitions of spontaneously combustible material and dangerous
when -wet material, which could be used to clarify the RCRA characteristic. Specifically, DOT
identifies an ignition time and violent reaction rate. Likewise, OSHA defines pyrophoric, unstable
reactive, and water reactive, specifying reactive conditions such as shocks, pressure, and temperature
which define the characteristic. The Basel Convention also defines similar terms.
References to DOT regulations are outdated. Forbidden explosive are no longer defined in
49 CFR 173.51. The current DOT regulations define forbidden explosives at 49 CFR 173.54. Other
explosives are defined at 49 CFR 173.50. 49 CFR 173.88 no longer exists.
14 45 Federal Register 33109.
15 45 Federal Register 33110.
Page 3-17
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Exhibit 3-3
Other Definitions of Reactivity
DOT (49 CFR 173.124)
Spontaneously combustible material is a pyrophoric material, that is a liquid or solid that, even in
small quantities and without an external ignition source, can ignite within five minutes after coming
in contact with air.
A self-heating material is a material that, when in contact with air and without an energy supply, is
liable to self-heat.
A dangerous when wet material is a material that, by contact with water, is liable to become
spontaneously flammable or to give off flammable or toxic gas at a rate greater than 1 liter, per
kilogram of the material, per hour.
OSHA (29 CFR 1910.1200)
A pyrophoric chemical is a chemical that will ignite spontaneously in air at a temperature of 130°C
or below.
An unstable reactive chemical is a chemical that in the pure state, or as produced or transported,
will vigorously polymerize, decompose, condense, or will become self-reactive under conditions of
shocks, pressure or temperature.
A water reactive chemical is a chemical that reacts with water to release a gas that is either
flammable or presents a health hazard.
Basel Convention Characteristic
An explosive is a solid or liquid capable by chemical reaction of producing gas at such a
temperature and pressure and at such speed as to cause damage to the surroundings.
Substances or wastes liable to spontaneous combustion are liable to spontaneous heating under
normal conditions encountered in transport, or to heating upon contact with air, and being then
liable to catch on fire.
Substances or wastes which, in contact with water, emit flammable gases are substances or wastes,
which by interaction with water, are liable to become spontaneously flammable or to give off
flammable gases in dangerous quantities.
Substances or wastes that cause liberation of toxic gases in contact with air or water are
substances or wastes that, by interaction with air or water, are liable to give off toxic gases in
dangerous quantities.
Organic peroxides are organic substances or wastes which contain the bivalent O-O structure are
thermally unstable substances which may undergo exothermic self-accelerating decomposition.
Page 3-18
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3.4.3 Potential Gaps Related to Reactivity Test Methods
Reactivity characteristic lacks test method(s). When the Agency promulgated the reactivity
characteristic in 1980, no available tests were identified for use in defining the reactivity characteristic
because:
They were too restrictive and were confined to measuring how one specific
aspect of reactivity correlates with a specific initiating condition or stress.
Testing the reactivity of a sample does not necessarily reflect reactivity of the
waste, because reactivity varies with properties including mass and surface
area.
Most available tests required subjective interpretation of results.
Existing methods were not developed for testing wastes.
Although EPA has identified a test method (Method 9010) for reactive sulfide and/or cyanide
bearing wastes, the Agency has not identified suitable test methods to fully define the reactivity
characteristic.
3.5 Potential Gaps Associated with the Toxkity Characteristic
3.5.1 Definition of Toxicity Characteristic
The toxicity characteristic was designed by EPA to reduce risks to public health from chronic
exposures to groundwater contamination caused by releases of toxic waste constituents. The Agency
found "persuasive evidence that the contamination of groundwater through the leaching of waste
contaminants from land disposed wastes is one of the most prevalent pathways by which toxic waste
constituents migrate to the environment."16 The legislative history of RCRA and EPA's case studies
of damages from hazardous waste management were cited as support for focusing the toxicity
characteristic exclusively on groundwater pathway risks.
EPA originally listed 14 contaminants as part of the toxicity characteristic. Subsequently, EPA
added another 26 substances to the list, as shown in Exhibit 3-4. These 40 TC chemicals were
selected because:
The chemicals were included on the 40 CFR Part 261 Appendix Vm list of
"hazardous waste constituents that have been "shown to have toxic,
carcinogenic, mutagenic, or teratogenic effects," and
Appropriate chronic toxicity information had been developed and adequate fate
.and transport data were available to allow the modeling of groundwater fate
and transport for each constituent.
17
16 45 Federal Register 33110, May 19, 1980.
17 55 Federal Register 11801, March 29, 1990. In finalizing the revised toxicity characteristic, however, the
Agency used a generic DAF of 100 in a subsurface fate and transport model to set the regulatory levels.
Page 3-19
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Exhibit 3-4
TC Constituents and Regulatory Levels (mg/1)
Arsenic
Barium
Benzene
Cadmium
Carbon tetrachloride
Chlordane
Chlorobenzene
Chloroform
Chromium
o-Cresol
m-Cresol
p-Cresol
Cresol
2,4-D
1,4 Dichlorobenzene
1 ,2-Dichloroethane
1,1 Dichloroethylene
2,4-Dinitrotoluene
Endrin
Heptachlor (and its epoxide)
5.0
100.0
0.5
1.0
0.50
0.030
100.0
6.0
5.0
200.0
200.0
200.0
200.0
10.0
7.5
0.5
0.7
0.13
0.02
0.008
Hexachlorobenzene
Hexachloro- 1 ,3-butadiene
Hexachloroethane
Lead
Lindane
Mercury
Methoxychlor
Methyl ethyl ketone
Nitrobenzene
Pentachlorophenol
Pyridine
Selenium
Silver
Tetrachloroethylene
Toxaphene
Trichloroethylene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2,4,5-TP (Silvex)
Vinyl chloride
0.013
0.5
3.0
5.0
0.4
0.2
10.0
200.0
2.0
100.0
5.0
1.0
5.0
0.7
0.5
0.5
400.0
2.0
1.0
0.2
Source: 40 CFR 261.24.
Thus, EPA found these chemicals to be among those posing the greatest risk to humans from chronic
groundwater exposure.
The remainder of Section 3.5 evaluates the TC in five steps:
Section 3.5.2 examines whether new data on the toxicity and persistence of TC
analytes and updated groundwater transport modeling techniques would result
in allowable TC leachate concentrations different from those established in
1990.
"Section 3.5.3 presents screening-level exposure and risk modeling methods and
results that are used to evaluate whether the current TC chemicals could pose
risks to human health and environmental receptors through the inhalation
pathway.
Sections 3.5.4 and 3.5.5 evaluate potential risks from TC chemicals to human
health through surface water pathways and indirect pathways, respectively.
These risks are evaluated by comparing toxicity and fate and transport values
to defined risk-related criteria, both singly and in combination, and by
reviewing the results of the Agency's multipathway risk modeling for the
Page 3-20
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analytes that was performed as part of the proposed Hazardous Waste
Identification Rule (HWIR-Waste) development.
Sections 3.5.6 and 3.5.7 evaluate the potential for acute adverse health effects
of exposures to TC analytes and potential risks to ecological receptors from
TC analytes, respectively.
3.5.2 Changes in Groundwater Pathway Analysis .
This section of the Scoping Study explores two issues related to the current TC regulatory
levels: (1) whether new toxicity data indicate a potential need to revise the regulatory levels; and (2)
whether, in light of recent developments in groundwater modeling techniques, the current dilution and
attenuation factor (DAF) value of 100 still provides a reliable basis for assuring that human health is
protected against risks from groundwater exposures to TC chemicals.
Revisions to MCLs and Toxicity Criteria
The lexicological bases for the establishment of TC analyte regulatory levels were chronic
lexicological and health-based regulatory criteria that were current at the time of promulgation. These
included Safe Drinking Water Act Maximum Contaminant Levels (MCLs), Reference Doses (RfDs),
and Risk-Specific Doses (RSDs) based on ingestion pathway Cancer Slope Factors (CSFs). For almost
all of the TC analytes, these values have not changed since 1990. The few changes have included:
A reduction in the RfD for p-cresol by a factor of ten and the withdrawal of
the MCL of 50 ug/1 for lead and its replacement with an Action Level of 15
ug/1. For cresol and lead, the reductions in RfDs and promulgation of Action
Levels indicate that the lexicological evaluation of these chemicals has
changed such that the TC regulatory levels may be less protective than was
originally intended. The changes for both of these analytes were an order of
magnitude or less.
The withdrawal of the MCL for silver, with its replacement by an SMCL at
the same value. This change simply means that the critical toxic effect for
silver (argyria, which is the collection of dark pigment in the skin and mucous
membranes) has been downgraded from a health effect to a cosmetic effect.
In addition, the RfD for pentachlorophenol has been reduced from 2 mg/1 to
3xlO"2 mg/1. More importantly, since the TC was revised, the Agency has
-promulgated a cancer slope factor for this compound, which is a suspect
human carcinogen. Thus, the critical toxic endpoint has been changed from
non-cancer to cancer induction. The promulgation of the Cancer Slope Factor
implies that a much lower TC regulatory level (about 1000 times lower) would
.be needed to achieve the same level of protection against cancer risks as
originally intended when the TC was promulgated.
Page 3-21
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Advances in Groundwater Modeling
To develop the existing TC regulatory levels, the Agency used the EPAMCL model to
estimate the likely extent of dilution after the release of waste constituents from waste management
units during their transport to the nearest drinking water wells.18 These calculations were conducted
for municipal solid waste landfills and Subtitle D surface impoundments, taking into account the
geochemical properties of the constituents, the size and configuration of the units, the vadose zone and
groundwater regimes beneath the units, and the distribution of distances in the downgradient direction
to the nearest drinking water well. Groundwater regimes were defined using distributions of transport
parameter values typical of conditions throughout the United States. Receptor wells were assumed to
be in the groundwater plume at a distribution of distances derived from a Subtitle D facility survey.
Simulation methods were used to derive estimates of dilution-attenuation factors (DAFs) for each
constituent and each type of waste management unit. After reviewing the results, the Agency elected
to calculate acceptable leachate concentrations (regulatory levels) for each TC analyte using a single
DAF value of 100. In other words, the threshold leachate concentration of each analyte above
which wastes would be identified as TC hazardous was set equal to allowable drinking water
concentration or other benchmark (10~5 cancer risk or Hazard Quotient (HQ) = 1.0) for the analytes
multiplied by 100.
Since the TC was promulgated, the Agency has continued to use the same general approach to
evaluate the groundwater transport of pollutants in developing RCRA regulations. The exact
techniques used in this modeling, however, have changed significantly. In recent rulemakings, the
Agency has used an updated version of the EPAMCL model, known as EPACMTP, to derive
constituent-specific DAFs for a wide range of pollutant releases from hazardous and non-hazardous
waste management units. This model employs many of the same basic transport algorithms as the
EPAMCL, with several important differences, including the following:20
The EPACMTP model uses a detailed metals speciation model (MINTEQA) to
estimate leachate concentrations from wastes of defined ionic composition,
whereas the EPAMCL model did not employ such a model;
The EPACMTP, unlike EPAMCL, can model the adsorbtion to soil and
transformation of organic waste constituents by hydrolysis into more toxic (or
less toxic) transformation products;
The EPACMTP directly simulates the interface between the saturated and
vadose zones;
-The EPACMTP model can simulate groundwater mounding under management
units, whereas the EPAMCL could not; and
1C
A detailed discussion of the groundwater modeling approach used by EPA in support of the TC rule can
be found at 55 Federal Register 11816, March 29, 1990.
19 Ibid at 11827.
20 A detailed discussion of the EPACMTP model can be found in U.S. Environmental Protection Agency,
Office of Solid Waste, EPACMTP Background Document. 1995; and EPACMTP Background Document for
Metals. Volume 1; Methodology. 1995.
Page 3-22
-------
The EPACMTP model provides more flexibility in modeling finite, versus
infinite, source terms.
Recent applications of the model also used somewhat different assumptions regarding waste
and facility characteristics, hydrogeological regimes, climatology, and receptor locations than those
used in the development of the TC. Therefore, it is not possible, except in a very general way, to
simply compare the DAF value used in establishing the TC allowable leachate concentrations with the
constituent-specific DAF values for the same constituents derived in the subsequent analyses. In
addition, DAF values derived for metals using the EPACMTP vary with the initial concentration of the
constituent in the waste, because the model incorporates saturable binding and transport phenomena.
In contrast, the DAFs derived using the EPAMCL model are concentration-invariant under most
conditions.
efforts.
Recently, EPA has employed the EPACMTP model in two major regulatory development
EPA applied the model in its development of proposed risk-based exit levels
for the Proposed Hazardous Waste Identification Rule for Process Waste
(HWIR-Waste).21 In that analysis, EPACMTP was used to back-calculate
concentrations of constituents in wastes and in waste leachate corresponding to
specific risk levels through groundwater exposures. The Agency is currently
revising the proposed HWIR-Waste exit level groundwater risk modeling
methods in response to comments from the Science Advisory Board arid from
other technical reviewers. Thus, the results of this modeling presented in this
Scoping Study should be regarded as preliminary.
In the Phase IV LDR regulatory development effort for mineral processing
wastes, the model was used to derive constituent-specific DAFs for mineral
processing wastes disposed of in surface impoundments and waste piles.22
The DAFs were then used to derive groundwater pathway risk estimates for
exposure to waste constituents.
The results of these analyses have been used to evaluate the extent to which changes in
modeling techniques may have affected the assessment of groundwater fate and transport relative to
the assessment used to derive the TC regulatory concentrations. As noted previously, a simple
comparison of DAF values and/or calculated risk levels from the different modeling efforts is not
possible without further analysis since the more recent modeling employs different groundwater
transport models and different assumptions regarding facility characteristics, groundwater regimes, and
receptor locations. In the case of the mineral processing risk assessment, for example, DAF values
were derived specifically for facility sizes representative of the mineral processing industry, rather than
Subtitle D management units. In addition, groundwater modeling was performed using climatologic
data primarily from drier regions where many mineral processing facilities are located. While
21 U.S. Environmental Protection Agency, Office of Solid Waste, Technical Support Document for the
Hazardous Waste Identification Rule: Risk Assessment for Human and Ecoloeical Receptors. August 1995.
22 U.S. Environmental Protection Agency, Office of Solid Waste, Regulatory Impact Analysis of the
Supplemental Proposed Rule Applying to Phase IV Land Disposal Restrictions to Newlv Identified Mineral
Processing Wastes. December 1995.
Page 3-23
-------
Subtitle D facilities were used to calculate releases for the HWIR-Waste proposal, the receptor wells
were assumed to be distributed uniformly in the downgradient direction, instead of being confined to
the plume. More importantly > the proposed exit levels were derived using a carcinogenic risk target of
10" , rather than 10 , and the 90th peircentile, rather than the 85th percentile, estimates of risk were
used. Using the 90th instead of 85th percentile of the risk output results in estimating higher risks for
a given receptor for a given constituent concentration and in more stringent (lower) exit levels. Thus,
the proposed HWIR-Waste risk calculations, especially for carcinogens, are substantially more
conservative in several important respects than those used to derive the TC regulatory levels.
In the mineral processing risk assessment, DAF values were derived for eight of the TC
analyte metals. For waste piles, the DAF values for the majority of the TC metals were considerably
higher than 100, the highest value being IxlO30 for lead. Barium, with a DAF value of 54, was the
only metal for which the mineral processing waste pile DAF was less than the value of 100 used in
the derivation of the TC regulatory concentrations. These results imply that the DAF value of 100
used in the TC derivation remains conservative for most metals when compared to values derived for
this population of facilities.
The situation is different, however, if the DAF values derived for mineral processing surface
impoundments are used as a basis for comparison. In this case, the majority of the DAF values for the
TC metals were less than 100. This finding suggests that the DAF value of 100 used to derive the TC
regulatory levels may not provide adequate protection against groundwater risks from surface
impoundments, which are the most frequent management type employed for non-hazardous industrial
wastes.
The large difference in DAF values for the two types of management units can be explained
partly in terms of the comparative aridity of the locations for which DAFs were calculated. Where
little moisture was available to drive transport from the waste piles through the vadose zone, DAF
values tended to be high. In contrast, the surface impoundments provided a water supply that drove
transport through the vadose zone into groundwater. The extent to which this effect would be seen in
moister regions of the country is not clear.
The HWIR-Waste proposed groundwater exit level calculations for the TC analytes are
summarized in Exhibit 3-5, and compared to the TC regulatory levels. The majority of the exit levels
are considerably lower (more stringent) than the corresponding TC regulatory levels. In 4 cases, the
TC levels are comparable to or less than the exit level. For 9 analytes, the ratio of the TC
regulatory level to the exit level is between 1 and 10. For 12 analytes, this ratio is between 10 and
100; for 5 analytes, the ratio is between 100 and 1,000; and for 6 analytes, the ratio is greater than
1,000.
This distribution confirms that, generally, the assumptions and modeling approaches used to
derive the HWIR-Waste proposed exit levels lead to somewhat mote conservative or more protective
results than those used to derive the TC regulatory levels. This conclusion holds true, even taking into
account that the cancer risk target is 10-fold lower for setting some of the proposed exit levels than
was used for setting the TC levels. For all but a few of the carcinogens among the TC analytes, the
proposed exit levels are far more than 10 times lower than the corresponding TC regulatory levels.
Thus, some other factors account for a significant proportion of the conservatism in these calculations.
23 In one of these cases (for endrin), however, the limiting risk, is ecological, rather than human health.
Page 3-24
-------
Exhibit 3-5
Comparison of TC Regulatory Concentrations
and HWIR-Waste Proposed Exit/Leach Levels
Analyte
Arsenic
Barium
Benzene
Cadmium
Carbon tetrachloride
Chlordane
Chlorobenzene
Chloroform
Chromium
Cresol, m-
Cresol, o-
Cresol, p-
Dichlorobenzene, 1,4-
Dichloroethane, 1,2-
Dichloroethylene, 1,1-
2,4-D
Dinitrotoluene, 2,4-
Endrin
Heptachlor
Heptachlor epoxide
Hexachloro-l,3-butadiene
Hexachlorobenzene
Lindane
Hexachloroethane
Lead
Chronic
Toxicity
Reference
Level, mg/la
0.05
1
0.005
0.01
0.005
0.0003
1
0.06
0.05
2
2
2
0.075
0.005
0.007
0.1
0.0005
0.0002
0.00008
0.00008
0.005
0.0002
0.004
0.03
0.05
TC Regulatory
Level, mg/la
5
100
0.5
1
0.5
0.03
100
6
5
200
200
200
7.5
0.5
0.7
10
0.13
0.02
0.008
0.008
0.5
0.13
0.4
3
5
HWIR-Waste
Groundwater
Exit Level
(mg/l)b
0.000148
15.5
0.0054
0.11
0.00161
0.000163
1.33
0.017
0.476
3.2
3.2
0.32
0.0108
0.00006
0.00018
0.6
0.112
32
No value
0.45
0.00691
0.000113
0.693
0.033
11.6
Ratio of
Regulatory
Level to
Exit/Leach
Level
33784
6.5
92.6
9.1
311 '
184
75.2
353
10.5
62.5
62.5
625
694
8333
3889
16.7
1.2
0.000625
30
0.0178
72.4
1150
0.577
90.9
0.4
Page 3-25
-------
Exhibit 3-5 (continued)
Comparison of TC Regulatory Concentrations
and HWIR-Waste Proposed Exit/Leach Levels
Analyte
Mercury
Methoxychlor
Methyl ethyl ketone
Nitrobenzene
Pentachlorophenol
Pyridine
Selenium
Silver
Tetrachloroethylene
Toxaphene
Trichloroethylene
Trichlorophenol, 2,4,5-
Trichlorophenol, 2,4,6-
Silvex
Vinyl chloride
MCL or HBLa
0.002
0.1
2
0.02
1
0.04
0.01
0.05
0.007
0.005
0.005
4
0.02
0.01
0.002
TC Regulatory
Level, mg/la
0.2
10
200
2
100
5
1
5
0.7
0.5
0.5
400
2
1
0.2
HWIR-Waste
Lowest Exit
Level (mg/l)b
0.138
No value
30
0.032
0.00041
0.06
0.357
No value
0.68
0.11
0.0128
4.2
0.0152
0.48
0.00006
Ratio of
Regulatory
Level to
Exit/Leach
Level
1.4
-
6.7
62.5
243902
83.3
2.8
-
1.0
4.5
39
95.2
132
2.1
3333
Notes:
a 55 Federal Register 11804, March 29, 1990.
b 60 Federal Register 66424-66432, December 21, 1995.
Some of this conservatism may be due to differences in modeling assumptions, rather than
modifications in modeling techniques. For example:
The HWIR-Waste proposed exit levels were derived to be protective of 90th
percentile receptors, while the TC levels were set to be protective of 85th
percentile receptors.
As shown in Exhibit 3-5, some HWIR-Waste proposed exit levels were driven
by exposure pathways other than groundwater.
Page 3-26
-------
The proposed HWIR-Waste exit levels and the TC regulatory levels were
designed for different purposes. The TC levels are designed to provide a
method for identifying wastes that would otherwise be non-hazardous, while
the proposed HWIR-Waste exit levels would relieve wastes previously
identified as hazardous from stringent regulatory control.
These issues are discussed in more detail in Sections 3.5.3 and 3.5.4. Other differences in modeling
assumptions, such as the retention of constituents in waste management (loss terms) in TC modeling
only and the differences in the assumed location of wells relative to the contamination source,
influence the results in the other direction.
Summary. Based on the preceding analyses, only general conclusions can be drawn about
whether there are any significant gaps in the TC associated with the specific regulatory levels set for
individual constituents. The wide range in the mineral processing DAF values illustrates the high
degree of variability associated with specific groundwater modeling assumptions, and does not
necessarily indicate whether the DAFs should be considered less or more protective than when they
were originally derived. The HWIR-Waste proposed exit level calculations, on the other hand, suggest
that the application of more recent modeling techniques might result in more conservative transport
calculations. Some, but not all, of this greater level of protectiveness reflects a policy decision by the
Agency regarding what proportion of receptors should be protected to the target risk level. In
addition, advances in modeling techniques and differences in specific input assumptions also affect the
differences in the apparent levels of protectiveness.
3.5.3 Potential Inhalation Pathway Risks Associated with TC Analytes
This section investigates the general level of protectiveness of the allowable TC concentrations
against direct inhalation, a risk that the TC was not specifically intended to protect against. EPA
analyzed this issue by performing screening-level risk calculations for long-term air releases of the TC
constituents from Subtitle D facilities. EPA used the CHEMDAT8 model using facility characteristic
parameters for surface impoundments and land application units (LAUs). Release estimates for all of
the organic TC analytes were developed for two scenarios.
In the first scenario, releases were estimated from the same "high-end" surface
impoundments and LAUs that were modeled in the proposed HWIR-Waste exit
level modeling.
The second scenario modeled releases from the "central tendency"
impoundments and LAUs, which were considerable smaller and shallower than
-the high-end units.
In both release scenarios, the concentrations of the organic TC analytes were assumed to be at the TC
regulatory level for liquid wastes in surface impoundments and at 20 times the TC levels for
nonwastewaters in land application units. The latter assumption roughly estimates the maximum
concentration of the TC analyte that could be present without the waste being hazardous, assuming
efficient leaching using the TCLP. For analytes that do not leach well, this approach may
underestimate exposure concentrations and risks associated with air releases from non-hazardous
industrial wastes, since nonwastewaters with high concentrations of constituents would not be
identified as hazardous by the TCLP. Average releases to air were calculated for an assumed 40-year
Page 3-27
-------
facility life-span under both scenarios. The basic approach and input assumptions used in the
modeling are summarized in Exhibit 3-6.
The organic TC analytes for which releases were modeled vary widely in molecular weight,
vapor pressure, Henry's Law constant, and other physical properties that affect releases to air. Thus,
the extent of release of these chemicals to air from land disposal facilities might be expected to differ
widely. This is true to some extent; but, as can be seen in Exhibit 3-7, the estimated release of these
compounds from land application units and surface impoundments over the expected facility life-span
varies only moderately. In the case of the high-end land application units, between approximately 7
percent and 100 percent of the chemicals entering the units are released to the air over the facility life.
The average proportion of the analytes released from these units was 81.6 percent, and the calculated
releases were greater than 95 percent for two-thirds of the organic TC analytes.
The results were similar for the central tendency LAU. Releases ranged from 27 to 100
percent of the analytes, and the average proportion released was 96.3 percent. The explanation for the
predicted higher proportional releases from the central tendency LAU is not clear, but may be related
to the shallower tilling depth assumed for the central tendency unit (0.2 compared to 0.3 meters).
The proportions of the TC analytes released from surface impoundments are shown in the final
two columns of Exhibit 3-7. The releases ranged from 6 to 77 percent of the applied total per year for
the high-end impoundment, with an average release of 55.5 percent per year.24 Proportionate
releases were again higher from the central tendency unit, ranging from 15 percent to 88 percent, with
an average of 71.2 percent released annually. Similar to the situation for the LAUs, the higher
proportional releases from the central tendency unit may be due to its considerably shallower depth
(2 meters) compared to the high-end unit (7 meters).
The limited impact of a chemical's Henry's Law constant on air releases is somewhat
surprising in light of the broad spectrum of solubility and vapor pressure reflected in the chemicals
modeled. Perhaps it can best be understood as indicating that, in the long run (a year or more), a high
proportion of any of these organic chemicals placed in uncovered land management units will be
released to the air, provided other removal pathways are not important. In actual practice, some land
application units are covered to some extent, and other removal processes, such as leaching, biological
and chemical degradation, and binding to soil or sediment, compete to reduce air emissions
significantly.
EPA calculated chronic risks from inhalation pathway exposures for all organic TC. analytes.
To calculate exposure concentrations, EPA multiplied release estimates by the long-term fenceline
dispersion coefficients used in the proposed HWIR-Waste exit level calculations for the high-end.and
central tendency surface impoundments and LAU releases. The fenceline dispersion coefficients are
used to represent the nearest credible residential exposure locations, in keeping with the proposed
HWIR-Waste risk methodology. Exposure durations are assumed to be 30 years in the high-end
exposure release and exposure scenario, and 9 years in the central tendency scenario.
24'
' Release from surface impoundments were estimated on an annual basis, rather than on a facility life-time
basis because these units receive a constant and continuous flow of wastes throughout the facility life, with liquid
flowing out of the unit after an assumed dwell time. In contrast, once a waste is added to an LAU, it is
assumed to remain in the facility to volatilize throughout the facility life-span.
Page 3-28
-------
Exhibit 3-6
Summary of Inhalation Pathway Screening Methods,
Input Data, and Models Used for Bounding Risk Analysis
Modeling Procedures
Estimate release proportions at TC regulatory concentrations
Estimate exposure concentrations using fenceline dispersion coefficients from HWIR-Waste modela
Estimate risks using IRIS and HEAST toxicity values (RfCs and Unit Risk values)
Subtitle D Surface Impoundment from Proposed HWIR-Waste Risk Analysis
HIGH-END CENTRAL TENDENCY
40,000 square meters
40-year lifespan
Depth 7 meters
2,000 square meters
' 40-year lifespan
Depth 2 meters
'Generic" Land Application Unit from Proposed HWIR-Waste Risk Analysis
HIGH-END
900,000 square meters
40-year lifespan
Tilling depth 0.3 meters
Long-Term Release Values
CENTRAL TENDENCY
61,000 square meters
40-year lifespan
Tilling depth 0.2 meters
Estimated over facility life using CHEMDAT8 model
Modeled at TC concentrations for surface impoundments
Modeled at 20 times TC concentrations for land application units
Assumed persistence in management units (except vinyl chloride)
Chronic Exposure Durations
High-end exposure duration = 30 years
Central tendency exposure duration = 9 years
Chemicals Modeled
All organic TC analytes
Differ by seven orders of magnitude in Henry's Law constant
Have molecular weight from 30 to 410
Are rapidly degrading to very persistent
-* Technical Support document for the Hazardous Waste Identification Rule: Risk Assessment for Human and
Ecological Receptors. US. Environmental Protection Agency, Office of Solid Waste, August 1995.
Page 3-29
-------
Exhibit 3-7
Emission Fraction for Air Releases of Volatile TC Analytes
TC Analyte
Benzene
Carbon tetrachloride
Chlordane
Chlorobenzene
Chloroform
m-Cresol
o-Cresol
p-Cresol
Cresol
2,4-D
1,4 Dichlorobenzene
1,2 Dichloroethane
1,1 DicWoroethylene
2,4 Dinitrotoluene
Endrin
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Hexachloro-l,3-butadiene
Hexachloroethane
Lindane
Methoxychlor
Methyl ethyl ketone
Nitrobenzene
Pentachlorophenol
Pyridine "
Tetrachloroethylene
Toxaphene
Trichloroethylene
2,4,5 Trichlorophenol
2,4,6 Trichlorophenol
2,4,5-TP (Silvex)
Vinyl chloride
kH
5.5xlO'3
2.9xl(T2
6.7xlO'5
4.4xW3
4.0X10-3
8.8xlO'7
1.6xlO'b
8.2xlO'7
4.5xlO'b
2.8x10^
l.SxlO'3
2.5xlO'2
1.5xlO'7
1.2xlQ-b
5.9X1Q-4
8.3xlO'6
7.5X10-4
2.4xlO'2
3.6xlO'3
3.4xlO'b
6.3xlO'6
3.6xlO'5
2.1xlO'5
1.4X10'3
7.0xlO'3
1.7xl(T2
3.4xlO'b
l.lxlO'2
4.4xlO*
4.1x10*
1.3x10*
8.4xlO-2
Fraction Emitted From:
Land Application Unit
Central
Tendency
0.9984
0.9984
0.9984
0.9984
0.9984
0.8228
0.9749
0.8249
0.9678
0.9984
0.9984
0.9984
0.9984
0.9984
0.2696
0.9984
0.9983
0.9984
0.9984
0.9984
0.9984
0.9984
0.9984
0.9984
0.9984
0.9984
0.9984
0.9984
0.9984
0.9979
0.9984
0.9984
0.9984
High-End
0.9984
0.9984
0.6301
0.9984
0.9984
0.2225
0.3384
0.2233
0.3256
0.6866
0.9984
0.9984
0.9984
0.9417
0.0674
0.9984
0.5730
0.9984
0.9984
0.9984
0.9984
0.9979
0.9984
0.9689
0.9983
0.9822
0.9984
0.9984
0.9984
0.4889
0.7077
0.9984
0.9984
Surface Impoundment
Central
Tendency
0.8661
0.8578
0.6649
0.8564
0.8676
0.2093
0.3651
0.2105
0.3550
0.6970
0.8483
0.8659
0.8769
0.7280
0.1466
0.8160
0.6558
0.8211
0.8261
0.8335
0.8246
0.7759
0.8526
0.7851
0.8021
0.7827
0.8519
0.7891
0.8604
0.5733
0.6830
0.8203
0.8829
High-End
0.7451
0.7318
0.4413
0.7294
0.7475
0.0858
0.1713
0.0864
0.1648
0.4722
0.7163
0.7443
0.7631
0.5151
0.0575
0.6662
0.4287
0.6744
0.6824
0.6928
0.6793
0.6038
0.7174
0.5981
0.6379
0.5975
0.7224
0.6282
0.7359
0.3339
0.4571
0.6735
0.7733
Page 3-30
-------
Exhibit 3-8 summarizes the results of the screening-level risk estimation for the TC analytes
having inhalation pathway toxicity values in IRIS or HEAST (as discussed below). The first eight
columns of the results indicate whether the estimated lifetime cancer risk associated with managing the
analytes at the TC (or the TC multiplied by 20) concentrations in the various management units would
be greater than 10~5 or if the inhalation pathway hazard quotient (HQ) would exceed 1.0. These risk
threshold values are the same as those used in developing the TC analyte concentrations for
groundwater exposures. For the 16 TC analytes with IRIS Unit Risk values, inhalation pathway cancer
risks greater than 10"5 are not predicted for any of the TC analytes released from the central tendency
surface impoundment. In contrast, cancer risks above 10"5 are predicted for 12 of these analytes
released from the high-end impoundment.25 None of these analytes released from the central
tendency LAU would result in an inhalation pathway risk greater than 10"5. Releases of four analytes
(chloroform, 1,4-dichlorobenzene, 1,1-dichloroethylene, hexachlorobenzene, and toxaphene) from the
high-end LAU would result in risks above this level.
Of the four TC organics with inhalation RfCs, hazard quotients greater than 1.0 were
calculated for three analytes (chlorobenzene, methyl ethyl ketone, and nitrobenzene) released from the
central tendency surface impoundment. When releases are modeled from high-end impoundments, the
one additional chemical (1,4-dichlorobenzene) also has an HQ greater than 1.0. Exactly the same
pattern is seen for LAUs.
These results indicate that, under assumptions of no degradation or release to other pathways,
the cancer risks and non-cancer hazard indices associated with management of some of the organic TC
analytes may be above levels of concern previously used in amending the TC.
These risks may be overestimated if significant amounts of pollutants in waste are released
through other pathways or are degraded biologically or chemically. For this reason, EPA used the
proposed HWIR-Waste database to identify the TC analytes that are persistent in soil or water. As
shown in the last two columns of Exhibit 3-8, most of the organic analytes that exceed the air risk
targets under the assumption of no degradation are, in fact, not very persistent in either soil or water.
Using a cutoff value for degradation rate constants of 0.5 year"1, which corresponds to a half-life in
soil or water of about 17 months, only 3 of the organic TC analytes are expected to be very persistent.
The relatively short half-lives in water or soil may reduce the potential concern for inhalation pathway
risks associated with the other TC analytes to the same extent. These results illustrate the need for
more detailed, site-specific modeling of all of the transport and degradation processes.
Risks were calculated in this analysis for only those TC analytes having inhalation pathway
toxicity values (Reference Concentrations or Unit Risk values) in IRIS. If instead inhalation pathway
toxicity values were derived for the rest of the TC analytes from ingestion pathway values and used in
similar risk calculations, the number of chemicals for which cancer risks and particularly non-cancer
risks would exceed levels of regulatory concern would be much higher. These results have not been
included in Exhibit 3-8 because EPA considers the level of uncertainty associated with such
procedures to be unacceptably high.
The risks are greater from the high-end surface impoundment than from the central tendency surface
impoundment, despite the lower proportionate releases from the former units, because the total mass disposed in
the high-end unit and the total mass released are much greater. This result also occurs for the LAUs.
Page 3-31
-------
Exhibit 3-8. Inhalation Pathway Risks for TC Analytes and Their Dependence on Fate and Transport Properties
TC Analytc
Benzene
Carbon tetrachloricle
Chlordane
Chlorobenzene
Chloroform
1,4 Dichlorobenzene
1,2 Dichloroethane
1,1 Dichloroethylene
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Hexachloro-1 ,3-butadiene
Hexachloroethane
Methyl ethyl ketone
Nitrobenzene
Tetrachloroethylene
Toxaphene
Trichloroethylene
2,4,6 Trichlorophenol
Vinyl chloride
Cancer Risk Exceeds 10"s
Surface Impoundment
i
Central Tendency I High-End
~
1.50E-04
1.34E-04
ND ND
2.82E-03
ND ND
2.65E-04
7.31E-04
1.90E-04
2.44E-04
1.10E-03
2.06E-04
2.28E-04
ND ND
ND ND
--
2.75E-03
-
..
3.56E-04
Landfill
i
Central Tendency i High-End
1
I
|
I
ND i ND
i
! 5.69E-04
i
ND ! ND
i
i ND
i
! 1.44E-04.
i
1
1
! 2.47E-04
i
i
ND ! ND
ND ! ND
i
! 6.60E-04
i
I
* t ~-
HQ Exceeds 1.0
Surface Impoundment
i
Central Tendency i High-End
ND ND
ND ND
ND ND
2.55E+03 9.99E+04
ND ND
1.84E+02
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
I.02E+02 -.. 3.93E+03
4.67E+02 1.64E+04
ND ND
ND ND
ND ND
ND ND
ND ND
Landfill
i
Central Tendency i High-End
ND ND
ND ND
ND ND
5.74E+02 2.06E+04
ND ND
3.87E+01
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
2.30E+01 8.25E+02
1.15E+02 4.00E+03
ND ND
ND ND
ND ND
ND ND
ND ND
Persistent
in Water"
-
-
X*
--
-
-
--
--
X
X
-
-
-
--
--
ND
-
--
-
Persistent
in Soil
--
--
X*
--
--
--
-
--
--
X
X
-
--
-
-
-
ND
--
--
--
I
Notes:
a Degradation rate constant for soil or water less than O.S yr .
* For surface impoundments only; does not exceed at landfills.
X = Yes.
- = Risk or hazard is below threshold.
ND = No Data.
-------
Evaluation of the proposed HWIR-Waste exit level calculations for the TC analytes confirms
the potential concern for nongroundwater pathways. For some of the TC analytes, the HWIR-Waste
proposed exit level calculations indicated that non-groundwater pathways are significant. Findings
include the following:
For 9 of the TC analytes, pathways other than human groundwater exposure
drove the establishment of proposed exit levels.
For six of the analytes, ingestion of contaminated milk or vegetables was the
highest-risk exposure pathways.
For one of the pollutants, the driving non-groundwater exposure pathway was
direct inhalation.
' For two analytes, ecological risks rather than health risks drove the derivation
of proposed exit levels.
In all of these cases, the initial release was to air through volatilization. These indirect pathway risks
will be discussed in more detail in the following sections.
3.5.4 Potential Risks from Surface Water Exposures
This section investigates the general level of protectiveness of the TC regulatory levels against
surface water exposures, a risk that the TC was not specifically intended to address. Waste
constituents could be released to surface water from land management units through several
mechanisms:
Discharge of groundwater contaminated by leachate from waste management
units;
Transport of waste constituents to surface water bodies by runoff and overland
transport of wastes released from the management unit;
Direct releases through overland runoff of liquid wastes from surface
impoundments; and
Volatilization of constituents from land-based units, followed by deposition
onto surface water or onto soil that eventually finds its way into surface water
'bodies.
The surface water exposure pathways of potential significance for humans include direct
consumptive use (i.e., ingestion and dermal contact with domestic water) and dermal contact and
incidental ingestion of the surface water associated with recreational exposures. If the contaminants
are persistent in sediment, dermal contact and incidental ingestion of small amounts of sediment also
are possible exposure pathways.
26 Such releases are likely to be controlled by permit requirements for surface water discharges and through
facility design regulations.
Page 3-33
-------
All of these release and exposure pathways have been analyzed in the development of
hazardous waste management regulations and in other contexts. The experience gained in these
exercises has led the Agency to a number of general conclusions regarding the importance of surface
water exposures for human health risks:
For common waste management practices, surface water exposure cannot be
automatically ruled out as insignificant in comparison to groundwater,
inhalation, and other indirect pathways. >
The significance of surface water releases depends heavily on the management
practices employed by a facility and the specific interactions between surface
water and groundwater at the facility.
Generally, groundwater discharge significantly affects surface water quality
only where groundwater constitutes a significant proportion of the total surface
water in a water body. This pathway may be important for very large
management units that generate large amounts of leachate, but usually
significant surface water quality impacts are limited to relatively small streams
adjacent to management units and to on-site or adjacent ponds derived mainly
from leachate.
Exposure to volatile contaminants in surface water is generally limited because
these contaminants are depleted rapidly from surface water through
volatilization. Air releases from surface water may themselves be significant
from a health standpoint. Usually, however, volatilization from the
management unit itself dominates, unless the unit is covered.
Incidental ingestion and dermal contact with contaminated sediment tend not to
be significant exposure pathways for humans, because of their infrequency and
the relatively small amounts of contaminated sediment contacted (but see
below).
Indirect pathway exposures may be of concern, however. The contaminants
that persist in sediment and have a high capacity to bioaccumulate and
bioconcentrate are often the most significant contributors to human health
risks. This capacity may overcome the high dilution factors often associated
with releases to surface water. These persistent pollutants most often reach
human receptors through the consumption of contaminated fish or shellfish.
In evaluating the potential risks associated with proposed HWIR-Waste chemicals, EPA
identified contaminants for which surface water pathways were of potential concern. Whether or not
the surface water pathway was a concern depended on the waste treatment scenario. For wastewaters
managed in surface impoundments, surface water was not a human health risk for any of the TC
analytes. All of the proposed exit levels driving non-groundwater pathways for humans were
associated with volatilization followed by deposition on soil and did not involve surface water. For
nonwastewaters disposed in land application units and waste piles, however, more than 50 percent of
the proposed exit levels for the HWIR-Waste constituents are driven by pathways involving surface
Page 3-34
-------
water exposures.27 The driving (highest-risk) pathways were approximately equally divided among
the contaminants between overland runoff followed by fish uptake, and overland runoff followed by
surface water ingestion. These results must be interpreted cautiously. The analysis of the proposed
HWIR-Waste exit levels cited above gives only a comparative, not an absolute, indication of the
importance of the surface water exposure pathways for waste piles and land application units. The
proposed exit levels calculated for these types of units are generally higher than those associated with
surface impoundments, for example, indicating that the magnitude of the risks from wastes piles and
land application units are, in general, lower than those associated with surface impoundments.
Summary. The preceding analysis has explored the possibility that significant risks to health
or the environment may be associated with exposures through surface water pathways. While a
number of theoretical arguments suggest that such releases might be important under only a relatively
narrow range of conditions, the proposed HWIR-waste modeling results indicate that these pathways
may well be significant for some TC analytes disposed as non-hazardous industrial wastes. The
possibility that the surface water releases and exposures represent a potential gap in the TC, especially
for persistent and bioaccumulative chemicals, cannot be ruled out.
3.5.5 Potential Indirect Pathway Risks from TC Analytes
"Indirect" pathways are any pathways involving more than one environmental medium (e.g.,
groundwater, air, surface water, soil, sediment, and biota) between the release and the exposed
receptor. The initial release may be to any medium. Indirect exposure pathways often, but not
always, involve uptake of environmental contaminants by living organisms, which, in turn, are
consumed by human or other receptors. Some of the pathways discussed in the previous sections,
such as groundwater releases to surface water, are, strictly speaking, indirect. This section, however,
emphasizes pathways involving potential long-range transport of persistent pollutants and pathways
involving biota (crops, fish, or livestock) prior to human exposures.
Persistence, properties facilitating physical transport, and the potential to bioaccumulate in the
environment are critical in the indirect pathways, and the physical/chemical and environmental fate
properties of constituents significantly determine their movement through such pathways. Exhibit 3-9
summarizes some important physical, chemical, and environmental fate properties of the TC analytes
relating to persistence, partitioning behavior between environmental media, and bioaccufhulation. For
each parameter, the exhibit compares each constituent's value to a criterion or cutoff value that
roughly indicates whether the parameter will strongly influence the transport and partitioning of the
chemical in the environment in a multipathway analysis. The derivation of these criteria are discussed
in more detail in Section 4.3.2.
The first column identifies TC analytes with a high Koc (high Kd for metals),28 generally
indicating a propensity to bind to soils. A high value means that chemicals will leach only slowly to
soil, but would bind to particulates if they were released through runoff or into the air. Essentially all
of the chemicals with Koc values above 10,000 are pesticides. In addition, the majority of the TC
metals would be expected to bind to some extent to particulates.
27 Preliminary Report on Factors Important to Identifying Risk-Based Entry Characteristics: Analysis of
Hazardous Waste Idendfication Risk Models. Ogden Environmental and Engineering Services, August 1996.
28
The Koc is the organic carbon binding coefficient; the Kd is the soil-water dissociation constant.
Page 3-35
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Exhibit 3-9
Major Fate and Transport Parameters for TC Analytes
TC Analyte
1,1-Dichloroethene
1 ,2-Dichloroe thane
1 ,4-Dichlorobenzene
2,4.5-TP (Silvex)
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2,4-D
2,4-Dinitrotoluene
Arsenic
Barium
Benzene
Cadmium
Carbon tetrachloride
Chlordane
Chlorobenzene
Chloroform
Chromium
Cresol, m-
Cresol, o-
Cresol, p-
Endrin
Heptachlor
Heptachlor epoxide
Hexachloro-l,3-butadiene
Hexachlorobenzene
Hexachloroethane
Lead
Lmdane
Mercury
Methoxychlor
Methyl ethyl ketone
Nitrobenzene
Pentachlorophenol
Pyndine
Selenium
Silver
Tetrachloroethylene
Toxaphene
Trichloroethylene
Vinyl chloride
Koc/Kd>
10,000
ml/g
^
^
s
s
s
s
S
S
S
S
S
Henry's
Law
Constant
> Ws atm-
m3/mol
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
Half-life
in Air
> 0.15 yr.
/
/
S
s
Soil/Water
Degradation
Rate
Constant
< 0.5/yr.
S
s
s
s
s
s
s
s
s
s
s
s
Plant-Soil
BFC for
Forage Plants
>3.5
(ug/g)/(ug/g)
^
^
S
s
s
s
s
s
Beef
Biotransfer
Factor >
7.8XKT4
day/kg
i
S
s
s
s
s
s
s
s
s
s
s
s
s
Fish
BCF/BAF >
1000 I/kg
S
s
s
s
s
s
s
s
s
s
s
s
Page 3-36
-------
The next column on Exhibit 3-9 shows the Henry's Law constants (kH)29 for the TC
analytes, with values above 10"5 generally indicating a moderate to high capacity to volatilize from
soil-water systems, which may be the first step in an indirect exposure pathway. About half (19) of
the TC analytes have kH values above 10"5. As discussed in Section 3.5.3, variations in Henry's Law
constants did not strongly effect the predicted long-term release of the TC analytes from surface
impoundments and waste piles. Short-term releases, however, may be much more dependent on this
parameter.
The next two columns address the persistence of TC analytes in soils, water, and air. Data in
these two columns summarize information from the proposed HWIR-Waste database on the estimated
half-life of chemicals in air and the overall degradation rate constants in soils and surface water. Four
of the TC analytes are identified as having long half-lives in air and 12 are persistent (have low
degradation rate constants) in soil and/or surface water. The air half-life values must be interpreted
cautiously, as the proposed HWIR-Waste database contains this information on only about 20
chemicals. Metals and many high-Koc organics would also be expected to have long half-lives in air
if they were bound to particulates. As discussed earlier, the TC analytes with long half-lives in
soil/water systems include primarily the metals and chlorinated pesticides.
The final three columns of Exhibit 3-9 consider the propensity of TC analytes to
bioaccumulate hi aquatic and terrestrial ecosystems. The plant-soil bioconcentration factor (BCF) is an
estimate of the typical ratio of the concentration of a constituent in soil to the concentration in a
particular kind of plant (in this case, forage plants consumed by beef and dairy cattle). Similarly, the
beef biotransfer factor is an estimated typical ratio of the concentrations of pollutants in the diet of
beef cattle to the resultant concentrations in edible tissue. Finally, the BCF and bioaccumulation factor
(BAF) values for fish represent the typical ratios of pollutant concentrations in surface water to that in
fish tissue, considering only water exposures or considering all pathways, respectively. (These value
tend to be quite similar for most chemicals.) Although the exhibit indicates that several constituents
may bioaccumulate from soil to forage plants, in reality, only 2,4,5-trichloropropionic acid (Silvex) has
a very high bioconcentration potential. The value of the forage biotransfer factor for this pesticide is
five orders of magnitude greater than for any other chemical (greater than 106). Generally the same
chemicals have high beef biotransfer factors, fish BCFs, and BAFs, with barium, mercury, and lindane
bioconcentrating only in aquatic systems, and arsenic, chromium, selenium, and silver being significant
for the beef exposure pathways alone.
Summary. These single comparisons indicate the significant potential for many TC analytes to
be transported through multiple media to reach the ultimate receptors. The data in Exhibits 3-8 and
3-9 show that the chlorinated pesticides (i.e., chlordane, endrin, heptachlor, heptachlor epoxide,
hexachlorobenzene, methoxychlor, pentachlorophenol, and toxaphene), chloroform, and hexachloro-1,3-
butadiene have the potential to participate hi indirect exposure pathways and have non-groundwater
pathways as their driving pathways. In addition, several high-toxicity and persistent metals, such as
mercury, arsenic, and lead, also are of potential concern.
29 As noted previously, kH is the ratio of a chemical's vapor pressure to its water solubility.
Page 3-37
-------
3.5.6 Potential for Acute Adverse Effects of Exposures to TC Analytes
The TC was originally established based on the need to protect individuals from adverse health
effects due to chronic exposures to the TC constituents consumed in groundwater. This approach to
protecting against groundwater exposure risks is conservative because the relatively long time scale
involved in groundwater transport to receptors, under most reasonable assumptions, means that limiting
concentrations in any time period to the low chronic risk-based levels also will protect against short-
term adverse effects. Short transient exposures to high levels of groundwater contaminants are
extremely uncommon. Before the concentration of a pollutant reaches the relatively high level
required to cause acute effects, it generally will have exceeded the allowable chronic exposure level
for a long period of time.
This relationship may not apply to exposure through pathways not involving slow releases to
groundwater. For example, the rapid evaporation of volatile chemicals from a ruptured container, the
catastrophic release due to overtopping of a surface impoundment, or runoff erosion from an extreme
storm event have the potential to result in short-term acute exposures to humans and environmental
receptors. For this reason, EPA has evaluated the potential level of protectiveness of the TC against
acute exposures. EPA evaluated the potential for adverse effects associated with acute volatilization of
chemicals from land management units. The approach was analogous to the screening-level risk
modeling for chronic exposure, except that the short-term releases were calculated and exposure
concentrations were compared to short-term exposure standards. This analysis indicates that the short-
term concentrations of all of the volatile TC analytes calculated at the fenceline were far below
applicable short-term exposure standards (in this case, occupational exposure standards).
This simple modeling does not unconditionally eliminate the possibility of adverse effects from
acute exposures to the TC analytes. Unusual release events, such as fires, or explosions, could result
in higher exposures than calculated assuming simple volatilization. In addition, high winds or other
events could result in high concentrations of particle-bound metals and other non-volatile analytes.
The potential for these kinds of release events strongly depends on specific waste characteristics, site
conditions, and management practices.
3.5.7 Potential Risks to Ecological Receptors from TC Analytes
Risks to non-human receptors are the final category of risks evaluated by EPA. Like the
inhalation, surface water, and indirect pathway risks, they were not expressly factored into the
derivation of the regulatory levels for the TC analytes. While a substantial number of the TC
chemicals are toxic to ecological receptors, the protection of ecological receptors was not a specific
concern in the rulemaking. This section discusses potential gaps in the TC characteristic associated
with harm to ecological receptors.
Many of the same factors that contribute to potential risks for human receptors also contribute
to potential risks for ecological receptors. Generally, harm to environmental receptors requires release
of chemicals from containment and transport to sensitive receptors without extensive degradation or
extreme dilution, just as in the case of human health risks. Thus, the physical properties of chemicals
that contribute to persistence and transport in the environment, as shown in Exhibit 3-9, are indicators
of potentially significant risks for ecological receptors. The fact that most of the persistent chemicals
with high bioconcentration potentials are also pesticides, which are toxic to certain plants, insects, or
other animals, adds to the potential risks.
Page 3-38
-------
The degree of protection of ecological receptors afforded by the TC leachate concentrations
does not appear very high for many of the most toxic pesticides. Exhibit 3-10 compares the TC
regulatory levels to two basic measures of potential aquatic toxicity, the acute and chronic Ambient
Water Quality Criteria (AWQC) for the protection of aquatic life. It shows that, for many analytes,
the allowable leachate concentrations are many orders of magnitude above the corresponding AWQC.
The shaded boxes in the table identify TC analytes with regulatory levels greater than 1,000
times the AWQC. The chemicals falling into this category again include the chlorinated pesticides,
chlorobenzene, lead, mercury, silver, and 2,4,5-trichlorophenol. This ratio indicates that if the TC
analytes were released from wastes to groundwater and from there discharged to surface water, a
dilution of at least 1,000-fold would be required to reduce the concentration to levels not harmful to
aquatic biota. Such a scenario may be unlikely, however, because, as noted above, these chemicals
tend to bind strongly to soil and do not move readily in groundwater. (As is discussed in more detail
in Chapter 2, however, some of these chemicals were found in groundwater at concentrations above
health-based levels in the descriptions of environmental releases from non-hazardous industrial waste
management units.)
In a more likely scenario, the high ecotoxicity of these chemicals means that runoff transport
of particulate wastes at concentrations not considered hazardous under the TC could cause adverse
effects in water bodies near management units. As noted above, the concern for runoff exposures is
borne out to some extent by the proposed HWIR-Waste modeling, where proposed exit levels are
driven by this pathway for disposal in waste piles and land application units. In the case of silver and
endrin (two of the chemicals in shaded boxes in Exhibit 3-10), the proposed exit levels were driven by
runoff releases to surface water.
Summary. Based on these findings, it appears that the level of protectiveness of the TC is not
very high for some non-human receptors. At a minimum, the ecotoxicity parameters suggest a
potential concern associated with the aquatic toxicity of chlorinated pesticides, as well as a few other
chemicals. The severity of these potential gaps is addressed in more detail in later chapters.
3.6 Potential Gaps Associated with TCLP
This section reviews the technical basis for the Toxicity Characteristic Leaching Procedure
(TCLP) and discusses potential problems associated with its use based on a brief review of available
literature and data. Specifically, this section focuses on whether the TCLP fails to accurately predict
releases from identified classes of wastes into groundwater and non-groundwater pathways.
3.6.1 TCLP Background
In 1980, prior to development of the TCLP, the Agency adopted the Extraction Procedure (EP)
to identify wastes likely to leach hazardous concentrations of particular toxic constituents into the
groundwater under conditions of improper management.30 In 1986, the Agency proposed a modified
leaching procedure, the TCLP, to replace the EP.31 The Agency promulgated the final rule on the
30 45 Federal Register 33110, May 19, 1980.
31 51 Federal Register 21648, June 13, 1986.
Page 3-39
-------
Exhibit 3-10
Ratios of TC Leachate Regulatory Levels to
Ambient Water. Quality Criteria for Aquatic Life3
Chemical
Arsenic
Barium
Benzene
Cadmium
Carbon tetrachloride
Chlprdane
Chlorobehzene
1,4 Dichlorobenzene
Chloroform
Chromium
Chromium VI
o-Cresol
m-Cresol
p-Cresol
Cresol
2,4-D
1 ,2-Dichloroethane
1,1 Dichloroethylene
2,4-Dinitrotoluene
Endrin
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Freshwater AWQC
Concentration (ug/1)
Acute
850
-
5300
3.9
35200
2.4
250
250
28900
1700
16
-
-
-
118000
-
330
0.18
0.52
0.52
6
Chronic
190
-
1.1
- 0.0043 -
50 -'
50
1240
210
11
-
-
-
20000
-
230
0.0023
0.0038
0.0038
3.68
TC
Regulatory
Level
(mg/1)
5
100
0.5
1
0.5
0,03
-""'-100
7.5
6
5
200
200
200
200
10
0.5
0.7
0.13
0.02^
0.008 ' ,"
0.008
0.13
TC Leachate
Concentration
(ug/1)
5000
100000
500
1000
500
-- '. ?o
100000
7500
6000
5000
5000
200000
200000
200000
200000
10000
500
700
130
20
'?
~ - 8
130
Ratio of TC
Regulatory
Level
to AWQC
26
NA
0.09b
909
0.01
* 6.98E+04'' ,
, ^2.00E+04
- "«*,*'
150
4.8
24
455
NA
NA
NA r
NA
NA
0.025
NA
0.57
8.70E+04
2.1IE+04
2.11E+04
35
Page 3-40
-------
Exhibit 3-10 (continued)
Ratios of TC Leachate Regulatory Levels to
Ambient Water Quality Criteria for Aquatic Life
Chemical
Hexachloro- 1 ,3-butadiene
Hexachloroethane
Lead " " *\ ' " -.,,""
Lindane s «-" " 'f,
\ -
Mercury ~
'Methoxychlor ~
Methyl ethyl ketone
Nitrobenzene
Pentachlorophenol A
*"J"\ s , "
Pyridine
Selenium
'Silver , "£
2,4,5-TP (Silvex)
Tetrachloroethylene
>Toxaphene" " "A .
Trichloroethylene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Vinyl chloride
Freshwater AWQC
Concentration (ug/1)
Acute
90
980
'. n ""-
2 -'
/
, P.A
sr
27000
20!
20
S~ f > ^
-4.1 ^
5280
''0.7? ,'
45000
' 100 J
-
Chronic
9.3
540
3,2
^0.08
, 0.012'"
0.03
--
-
13'
5
0.12
840
- 0,0002
21900
- 63 /
970
-
TC
Regulatory
Level
(mg/1)
0.5
3
- 5^ '.
Oi4 "
0.2^
_ ""- 10 ^
200
2
, *'r 100 ,
5
1
- ' 5 r
1
0.7
0.5 "'"
0.5
400 ^
2
0.2
TC Leachate
Concentration
(ugfl)
500
3000
5000
400" . '
200
s -10000" ,
> /*
200000
2000
«, loom
5000
1000
- - 5000 ,-
1000
700
- JOO ~
500
400000
2000
200
Ratio of TC
Regulatory
Level
to AWQC
54
5.6
^ 1.56E+04
' 5.00B+04 ,
. 1.67E4-05, /
333E+06
NA
0.07a
' 7.69E-1-04
* f
NA
200
4,17E*05(
NA
0.83
2.50E+07- -
f* «
0.02
6.35E+04
2.1
NA
Notes:
a Shaded rows indicate that the ratio of the TC regulatory level to the AWQC for the analyte exceeds
1,000.
b Indicates ratio is to acute AWQC.
Page 3-41
-------
application of the TCLP in 1990.32 In finalizing the TCLP, the Agency intended to improve the
leachate test procedure and eliminate some of the analytical difficulties involved in the EP.
The TCLP is used to quantify the extractability of certain hazardous constituents from solid
waste under a defined set of laboratory conditions. This test is used to evaluate the leaching of TC
metals, volatile and semivolatile organic compounds, and pesticides from wastes. In principle, this
procedure simulates the leaching of constituents into gfoundwater under conditions found in a
municipal solid waste (MSW) landfill. The TCLP, however, does not simulate the release of
contaminants to non-groundwater pathways. The TCLP is most commonly used by EPA and state
agencies to evaluate the leaching potential of wastes, and for determining toxicity. The TCLP is
promulgated in Appendix n of 40 CFR Part 261.24(a) and has been designated as EPA Method 1311
in "Test Methods for Evaluating Solid Waste, Physical/Chemical Methods - SW-846."
In the TCLP, liquid wastes (those containing less than 0.5 percent dry solid material) are
"extracted" by filtering the wastes through a 0.6 to 0.8 \i glass fiber filter. Non-liquid samples (those
containing greater than or equal to 0.5 percent dry solid material) are:
Reduced to a particle size of less than 9.5 mm (liquid, if any, is separated
from the solid phase) and extracted with an acetate buffer solution with either
a pH of 5 or an acetic acid solution with a pH of 3, depending on the
alkalinity of the waste (wastes with a pH of 5 and above are extracted with the
acetic acid solution);
A liquid-to-solid ratio of 20:1 is used for an extraction period of 18 hours; and
The leachate is filtered and combined with the liquid portion of the wastes, if
necessary.
Contaminant analyses then are conducted on the extracts of the liquids and non-liquids.
3.6.2 Limitations of the TCLP
The Agency reviewed TC constituent and concentration data collected on releases from the
non-hazardous industrial waste management units discussed in Chapter 2 (see Exhibit 2-5). These data
show that, of the 15 TC constituents detected in at least three case studies, eight are present in
groundwater at levels much higher than their TC levels.33 If the wastes passed the TCLP before
being placed in the management units, this could indicate that the TCLP underestimated the long-term
releases for certain classes of wastes. One of the major limitations of these data, however, is that they
may not reflect current waste analysis or management practices. For example, some data represent
releases from waste disposal that occurred prior to implementation of the TCLP, and thus some of the
releases that exceed TC levels could be due to problems with other extraction procedures or to the lack
of any testing procedure. Nevertheless, some site data (not reported in Chapter 2) exists that may
represent problems with the TCLP. For example, the kiln residues from the treatment of spent
32
55 Federal Register 11827, March 29, 1990.
Note that the majority of these data were collected from on-site groundwater monitoring wells and not
from drinking water wells, and therefore actual risks likely are lower than would be indicated by these data.
Page 3-42
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aluminum potliners at one facility are disposed in a monofill as non-hazardous wastes. EPA
approved a delisting petition for the kiln residue waste based on TCLP data that showed the target
constituents in the TCLP extract to be below treatment standards (which, for the TC constituents, are
lower than the TC regulatory levels). When the leachate from the monofill was analyzed, however,
levels of arsenic were found to be higher than its TC level. Other hazardous constituents, including
cyanide and fluoride, were also found at levels higher than those predicted by the TCLP.
Several technical and practical issues have been raised by the regulated community and others
regarding the applicability of die TCLP for identifying hazardous waste. A number of comments were
submitted to the Agency in response to the June 13, 1986 proposal to replace the EP with the TCLP.
The Agency responded to the comments in the final rule, but also decided to continue to address
commenters concerns and further evaluate modifications to the TCLP. The Agency stated that further
improvements in the TCLP will be proposed as they are developed. Subsequent to that rulemaking,
additional concerns have been raised by commenters during later rulemakings (e.g., rules addressing
newly listed or identified wastes).
Some of the key issues regarding the TCLP identified from these comments on various
rulemakings and from other sources are outlined below.
TCLP underestimates leachate from some high alkaline wastes or environments. The high
alkalinity of some wastes may make the TCLP an inappropriate predictor of leachate composition. For
example, the addition of acid during the TCLP might not reduce the pH of high alkaline waste to the
same level as would occur over time in the environment. Thus, long-term leachate concentrations of
constituents that are insoluble at higher pH ranges may be underestimated in the TCLP leachate
compared to the actual leachate from the industrial landfills where a long-term acid environment (e.g.,
from acidic rain water) is present.
Some toxic metal constituents are more mobile at both the higher and the lower pH ranges.
For example, studies show that leaching of metals such as cadmium, chromium, and lead typically is
limited when the pH is in the range of about 8 or 9, but can increase significantly when the pH either
increases or decreases.36 Thus, if a waste is highly alkaline (e.g., pH >11) and the TCLP acidic
leaching medium lowers the pH to only about 8 or 9, then the concentrations of these metals in the
TCLP leachate could be significantly lower than would occur from either a highly alkaline or a highly
acidic environment (depending on a number of factors, such as characteristics of any co-disposed
wastes, type of treatment, and characteristics of the soil and rain water).
34 Lester Sotsky, Arnold & Porter, "Reynolds Metal Company's Gum Springs Facility." Memorandum to Steven
Silverman, U.S. EPA, September 26, 1996.
35 Note, however, that this list of issues is not meant to be comprehensive. Other issues, such as the potential
overestimation of the dilution simulated by the TCLP, may need further study.
36 van der Sloot, H.A., GJ. de Groot, and J. Wijkstra, "Leaching Characteristics of Construction Materials
and Stabilization Products Containing Waste Materials," in P.L. Cote and T.M. Gilliam, eds., Environmental
Aspects of Stabilization and Solidification of Hazardous and Radioactive Wastes. ASTM STP 1033, American
Society for Testing and Materials, Philadelphia, Pennsylvania, 1989; and Willis, et al., "When the TCLP Is Not
Enough: Leaching Tests for Solidification/Stabilization Technologies," Hazardous Materials Controls/Superfund
1991, Proceedings of the 12th National Conference, Hazardous Materials Control Research Institute, pp. 385-388,
December 3-5, 1991.
Page 3-43
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Several commenters to the June 13, 1986
TCLP proposal expressed concern regarding the
application of the TCLP to alkaline wastes. They
noted that no high alkaline wastes were included in
the development of the TCLP and, therefore, no
conclusions could be made concerning the actual
behavior of these wastes. The MEP, described in
the text box, is one test that the Agency and others
use that may better simulate the long-term leaching
behavior of such wastes.
TCLP underestimates the leachate
concentrations from oily wastes and some paint
wastes. Several reports indicate that oily and some
paint wastes tend to clog the filters used to separate
the extract from the solids prior to analysis, resulting
in under-reporting of the extractable constituent
concentrations.37 Several commenters on the June
13, 1986 TCLP proposal noted that, in the
development of the TCLP, the Agency tested only
11 wastes.38 These commenters argued that
increasing the variety of wastes (to include oily wastes, organic chemical wastes, and municipal
wastes) and the number of extractions performed could refine the TCLP and enhance its accuracy.
TCLP may not accurately mimic conditions commonly found in non-hazardous industrial
waste disposal. As discussed in the 1980 final EP rule, several commenters responding to the
proposed use of the EP for evaluating the leaching of hazardous constituents argued that the co-
disposal assumption is not applicable to wastes that are never co-disposed with municipal solid wastes
and thus do not leach at the aggressive rates characteristic of co-disposal situations. Thus, the
commenters stated, the leachate procedure does not simulate the conditions found in industrial waste
monofills. In response, the Agency stated that most wastes, even those that are unlikely to be
disposed in a municipal landfill, are likely to come into contact with some form of acidic leaching
medium during their management histories or could otherwise encounter environments that could cause
the wastes to leach comparable levels of toxic constituents.
This same debate occurred during development of the TCLP, and it continues today. For
example, the Lead Industries Association Inc., commenting on the Phase IV supplemental proposed
Multiple Extraction Procedure (MEP)
The MEP involves an initial extraction
with acetic acid and at least eight
subsequent extractions with a synthetic
acid rain solution (sulfuric/nitric acid
adjusted to pH 3). The MEP is intended
to simulate 1,000 years of freeze and
thaw cycles and prolonged exposure to a
leaching medium. One advantage of the
MEP over the TCLP is that the MEP
gradually removes excess alkalinity in the
waste. Thus, the leaching behavior of
metal contaminants can be evaluated as a
function of decreasing pH, where the
solubility of most metals increases.
Currently, the MEP is used in the
Agency's de-listing program.
.3$,
.,40
rule, cited an EPA study4" that stated that acetic acid leaching fluid could selectively solubilize
37 "Preliminary Proposal to Require the TCLP in Lieu of the Waste Extraction Test," Memorandum to James
Carlisle, Department of Toxics Substances Control, California EPA, from Jon Marshack, California Regional
Water Quality Control Board, December 18, 1995; and U.S. Environmental Protection Agency, Technical
Background Document and Response to Comments - Identification and Listing of Hazardous Waste - Method
1311-TCLP. F-90-TCF-S0004, April 1989.
38 Ibid.
39
61 Federal Register 2338, January 25,1996.
Page 3-44
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toxicants (specifically lead) and incorrectly classify
the material as hazardous when, in fact, no
mobilization (leaching) would be expected to occur
in the landfill environment. Kennecott Corporation
and National Mining Association, also in response to
the Phase IV supplemental proposed rule, stated
similar concerns. The SPLP (see text box at right)
is one test that has been considered for addressing
this issue.
TCLP may underestimate the chelation-
facilitated mobility of some waste constituents. A
recent analysis of the TCLP and Cal WET (see text
box at right) indicates that the low chelation41
activity of the acetate buffer used in the TCLP may
underestimate the ability of leachate containing
chelating agents to mobilize waste constituents.42
Cal WET uses a citrate buffer that approximates the
chelation ability of many other compounds of
landfill leachate and, thus, overcomes the constraints
of the TCLP test.
Synthetic Acid Precipitation Leach
Test (SPLP)
The SPLP is similar to the TCLP, but the
initial liquid-solid separation step has
been eliminated and the acetate buffer
extraction fluid has been replaced by a
dilute nitric acid/sulfuric acid mixture.
The TCLP addresses co-management of
industrial and non-industrial wastes in an
organic acid environment, a scenario that
does not match the disposal setting of
many treated wastes, while the SPLP
simulates disposal in an acid rain
environment. The SPLP is currently used
by several state agencies to evaluate the
leaching of TC hazardous constituents
from wastes.
TCLP does not account for the oxidation/reduction reactions occurring in landfills. A
recent study noted that the addition of iron filings to stabilize foundry sand wastes43 seems to mask
the potential leachability of lead by interfering with the TCLP.44 If metallic iron (iron filings) are
added to the waste, the lead concentration in the TCLP extract may be decreased by an oxidation/
reduction reaction to levels below the lead TC level. If, however, the waste is placed in a landfill or
surface impoundment, the iron oxidizes over time and loses its ability to further reduce the lead ions.
This results in the leaching of lead to the environment.
40
U.S. Environmental Protection Agency, "Performance Testing of Method 1312 QA Support for RCRA
Testing," p. m, June 1989.
41 The chelation property of a reagent (such as acetate and citrate) refers to the ability of the reagent to bind
with and solubilize metal contaminants. The low chelation ability of acetate buffer might result in fewer metal
constituents being leached into the extract.
42
"Preliminary Proposal to Require the TCLP in Lieu of the Waste Extraction Test," supra footnote 37.
Stabilized waste is a concern for the Scoping Study because some non-hazardous industrial waste either is
treated (e.g., using stabilization) to reduce the release of hazardous constituents or is derived from
characteristically hazardous waste that has been "decharacterized" via treatment
44
Douglas Kendall, "Impermanence of Iron Treatment of Lead-Contaminated Foundry Sand-NIBCO, Inc.
Nacogdoches, Texas," National Enforcement Investigations Center-Project PA9, April 18, 1996.
Page 3-45
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Another recent study reviewed the practice
of using iron as an additive in stabilizing paint
waste. The study notes that the iron reduces the
lead ions in paint waste to the less soluble metallic
lead, which is subsequently removed by filtration
from the leachate being analyzed. This use of iron
allows the lead-containing waste to pass the TCLP.
The study notes, however, that repeated leaching of
the same waste sample increases the leaching rate to
a point where lead is sufficiently solubilized to
exceed the TC regulatory level.
Finally, another study showed that
oxidation/reduction potential has a significant effect
on leaching of metals from stabilized waste
materials. This study showed that the leaching
of chromium increases significantly under highly
oxidizing conditions, and the leaching of arsenic,
vanadium, lead, and iron increase significantly under
reducing conditions.
TCLP may not predict long-term mobility
of organic contaminants in some treate
-------
Another study conducted on the long-term leaching performance of commercially stabilized
waste demonstrated a highly waste-dependent effect of time on the TCLP results.48 In this study,
TCLP extraction was performed on both the raw waste and the treated waste. The treated waste
consisted of samples at 28, 90, 200, 470, and 650 days after treatment. The results showed that
leachate values for some metallic wastes increased over time.
TCLP may not be appropriate for some contaminated soil. The Michigan Department of
Natural Resources (MDNR) believes that the TCLP is not appropriate for soils contaminated with
cyanides, sulfides, and hexavalent chromium.49 Furthermore, MDNR reports that the SPLP (see
previous text box) more accurately simulates the conditions of contaminated soil and therefore is an
appropriate alternative test for soil contaminated with cyanides, sulfides, and hexavalent chromium.
TCLP does not predict releases to non-groundwater pathways. As discussed in Section 3.4,
the TCLP was designed to simulate the leaching of waste constituents to groundwater and not for
releases to non-groundwater pathways. The TCLP does not simulate the release of volatile organic
contaminants into air either directly or through entrained dust, nor does it simulate releases through
surface runoff.50
48 Peny, KJ, Prange, N.E., and Garvey, W.F., "Long-Term Leaching Performance for Commercially
Stabilized Waste," Stabilization and Solidification of Hazardous. Radioacdve. and Mixed Wastes. Vol. 2, ASTM
STP 1123, T.M. Gilliam and C.C. Wiles, Eds, American Society for Testing and Materials, Philadelphia, pp.
242-251, 1992.
Alternate Soil Leaching Procedures. Interoffice Memorandum to the Environmental Response Division
Staff from Alan J. Howard, Environmental Response Division, Michigan Department of Natural Resources,
January 5, 1995.
The TCLP does account for the loss of volatile contaminants that occur during the liquid/solid separation
and extraction process; however, this is only for correcting the leachate concentration, not for simulating releases
to air.
Page 3-47
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-------
CHAPTER 4. POTENTIAL GAPS ASSOCIATED WITH
NON-TC CHEMICALS
This chapter identifies potential gaps in the hazardous waste characteristics associated with
chemicals not on the toxicity characteristic list. Chemicals and chemical classes are identified as
potential gaps based on their hazardous properties such as toxicity to humans and ecological receptors,
their fate and transport properties such as persistence and bioconcentration potential, and their potential
for occurrence in non-hazardous industrial wastes. This approach to identifying gaps is complemented
by the approach discussed in Chapter 5, which identifies gaps in terms of the important environmental
risks and their potential association with waste management, rather than focusing on specific
chemicals.
4.1 Overview of Methodology
EPA identified potential gaps in the characteristics associated with non-TC chemicals through
a six-step process, as shown in Exhibit 4-1. Each of these steps is described below.
Step 1: Identify and Classify Known Non-Hazardous Industrial Waste Constituents
An essential task in this analysis is identifying a universe of chemicals that are either known
or likely to be present in non-hazardous industrial wastes, excluding TC analytes (which are addressed
in Chapter 3). In the analysis that follows, these two classes of chemicals are referred to as known
non-hazardous industrial waste constituents and possible non-hazardous industrial waste
constituents, respectively. As described in Section 4.2, the identification of the "known" non-
hazardous constituents is relatively straightforward, although reliable data on the composition of non-
hazardous industrial waste are limited. The data sources used to identify these constituents are shown
in the top panels of Exhibit 4-1. They are the non-hazardous industrial waste release descriptions
(discussed in Chapter 2), the Industrial Studies Data Base (ISDB), Effluent Guidelines Development
Documents, and Listing Documents from recent rulemakings for dyes and pigments and solvent
wastes. As discussed in Section 4.2, the distinguishing characteristic that makes a chemical a "known"
non-hazardous industrial waste constituent is that it has been documented through direct chemical
analysis to occur either in non-hazardous industrial waste or hi environmental media contaminated by
releases from non-hazardous industrial waste management units.
Step 2: Identify and Screen Possible Non-Hazardous Industrial Waste Constituents
In addition to the chemicals that are known to be present in non-hazardous industrial wastes,
EPA identified other chemicals that have a high likelihood of being present in such wastes and could
pose significant risks to human health or the environment. Unlike the known non-hazardous industrial
waste constituents, however, the possible waste constituents have not been confirmed as non-hazardous
industrial waste constituents through direct chemical analysis in any of the data sources used by the
Agency. To identify non-hazardous industrial waste constituents that could pose risks to human health
or ecological receptors, the Agency reviewed 36 lists of chemicals created for regulatory and advisory
purposes by EPA, other federal agencies, states, other countries, and advisory and scientific bodies.
These lists were originally created based on criteria such as toxicity, fate and transport characteristics,
production volume, widespread use, and detection in environmental media.
Page 4-1
-------
Exhibit 4-1 Flow Chart of Procedures Used to Identify Non-TC Chemicals Posing
Potential Gaps in the TC Characteristics
Effluent
Guidelines
Development
Documents
Known Non-
Hazardous Industrial
Waste Constituents
Exhibits 4-2,4-9
Regulatory, Advisory Lists
Exhibit 4-3
Screen Against
Single Toxicity and Fate
and Transport Criteria
Exhibits 4-4,4-5,4-6
Step 1: Known Non-Hazardous
, -* ' , -'* -. ' ^ *- __/.,"" -. ' - -V '^>..4'-;:"'
Industrial Waste
Screen Against TRI
Release Data
Exhibit 4-7
Possible Non-
Hazardous Industrial
Waste Constituents
Exhibit 4-8
Step 3: Hazard BasM Screening Criteria
- .- ' .--^' .'.£ i" -!:. ^'..-i-.i^e*;' ',.'.*- irj. «S^-j« =='= 'W'.^t'S'.ivKA^ji-:;....^
Known and Possible
Non-Hazardous Industrial
Waste Constituents
. ..
Step 2: Possible Non-Hazardous
dustrial \^te Coiastituents '
'
Screen Against
Single and Multiple
Toxicity, Fate and
Transport, Persistence, and
Bioaccumulation
Criteria, TSCA
Production Volumes
Exhibits 4-10,4-12,4-13,4-15
Identify Potential
Endocrine Disrupters
Exhibit 4-11
Identity Potential
LNAPL, DNAPL
Formers
Exhibit 4-14
Identify Acutely Hazardous,
Ignitable, Corrosive,
and Reactive Constituents
Exhibit 4-17
Identify HWIR-
Waste Risk Driving
Exposure Pathways
Exhibit 4-16
Identify Individual Chemicals
and Classes of Chemicals
Constituting Potential Gaps
Page 4-2
-------
Rather than include all the chemicals on these lists as possible non-hazardous industrial waste
constituents, EPA narrowed the list of chemicals to those most likely to pose significant risks to
human health and the environment. The screening was performed in two steps, as shown in the upper
right-hand panels of Exhibit 4-1. First, chemicals were screened with regard to individual toxicity and
fate and transport properties. Then, the resulting high-hazard chemicals were screened against 1994
national Toxic Release Inventory (TRI) release data, serving as a proxy for potential occurrence in
waste. Section 4.3 describes the process of compiling and screening possible non-hazardous industrial
waste constituents.
Step 3: Apply Hazard-Based Screening Criteria
In this step, which is described in detail in Section 4.4, EPA compared the lists of known and
possible non-hazardous industrial waste constituents and screened them against single and multiple
hazard-based screening criteria. In Step 2, individual chemicals that are possible non-hazardous
industrial waste constituents were screened on the basis of single indicators of hazard (e.g., a low
reference dose or a high bioconcentration factor). This step refines this analysis by examining both
the known and possible non-hazardous industrial waste constituents against single and multiple
indicators of toxicity, fate, transport, and occurrence in waste, and by reviewing the implications of
this screening for classes of chemicals.
Step 4: Review Relevant Multipathway Risk Modeling Results
Section 4.5 reviews the results of the multipathway risk modeling conducted as part of the
proposed HWIR-Waste (Hazardous Waste Identification Rule for Process Wastes) determination of exit
levels, where available for chemicals on the combined list of known or possible non-hazardous
industrial waste constituents. The proposed exit levels and risk-driving pathways provide information
on the relative risks posed by the various constituents and on the most important exposure pathways.
Step 5: Identify Potential Acute Hazards
In the prior steps, the evaluation of potential hazards associated with the possible and known
non-hazardous industrial waste constituents has focused on chronic toxic effects. In Section 4.6, the
possible and known constituents are compared to acutely hazardous chemical lists developed by EPA
and other regulatory agencies. This analysis thus addresses risks from acute exposures and from
physical hazards associated with reactivity, flammability, and corrosivity.
Step 6: Summarize Findings
Chapter 4 concludes by identifying non-TC chemicals and groups of chemicals that constitute
potential gaps in the hazardous waste characteristics. Section 4.7 presents a table identifying these
potential gaps, the rationale for their identification, and the major issues and data gaps remaining to be
resolved to judge the severity of these potential gaps.
42 Identify and Classify Known Constituents of Non-Hazardous Industrial Wastes
Chemicals present in non-hazardous wastes that have been released from non-hazardous
industrial waste management units into the environment may constitute potential gaps in the hazardous
waste characteristics. This section reviews the available evidence concerning such chemicals. Reliable
data concerning the chemical composition of non-hazardous industrial wastes, however, are quite
Page 4-3
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limited for two major reasons. First, such wastes may be generated by virtually any industrial facility
or operation and are inherently heterogeneous. Second, state requirements to analyze non-hazardous
industrial wastes and to report analytical results are quite limited.
In the course of this Scoping Study, the Agency identified four sources of information
regarding the composition of non-hazardous industrial wastes:
The descriptions of environmental releases from non-hazardous industrial waste
management facilities, compiled as part of this Scoping Study, which were
summarized in Chapter 2;
The Industrial Studies Data Base (ISDB), which includes information on point of
generation constituent concentrations on various industries;
Chemicals identified as being present in liquid non-hazardous wastes by EPA
Effluent Guideline Development Documents, as summarized in the Capacity
Analysis for the Phase m Land Disposal Restrictions (LDR) Rule; and
Chemicals identified as being present in non-hazardous industrial waste that
were not listed as hazardous wastes in background documents for recent
Agency listing/no-listing proposals for pigments and dyes industries and for
solvents.
The first source provides information on chemicals detected in environmental media (primarily
groundwater) that were released from non-hazardous industrial waste management facilities, while the
other three sources provide information on the composition of non-hazardous industrial wastes.
Although not reflected hi this Study, hi future investigations the Agency will consider examining the
constituents present in remediation waste from non-hazardous industrial waste management units.
The descriptions of environmental releases in Chapter 2 identify the constituents found in
environmental media near non-hazardous industrial waste management units, their maximum detected
concentrations, the types of units from which the releases occurred, and the industries responsible for
the releases. The release descriptions provide direct evidence of potential environmental exposure to
non-hazardous industrial waste constituents and damage to human health and the environment. They,
however, do not encompass all instances where non-hazardous industrial waste management has
resulted in releases to the environment or other potential risks. As noted in Chapter 2, the release
descriptions come from only a small proportion of the states. However, they do represent a large
proportion of the readily identifiable releases from facilities regulated by state non-hazardous industrial
waste programs.
In addition, some types of occurrences (e.g., fires and explosions) and units (e.g., waste piles)
are generally not regulated by these state programs, and would not show up in the records EPA
examined. The quantitative data from these descriptions generally were limited to groundwater
monitoring results. Few releases to other media were identified. In addition, the chemicals identified
tend to be those whose monitoring is required under existing regulatory programs. The potential for
identifying chemicals not already recognized as hazardous is therefore limited. Finally, the data
sources evaluated did not provide useful information on various types of uses constituting disposal,
such as cement additives, soil amendments, or aggregate.
Page 4-4
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The ISDB was the second source of data used to identify known waste constituents. EPA has
maintained this data set since 1982. It contains information on point-of-generation constituent
concentrations for 16 industries. The sources of information include RCRA Section 3007
questionnaires, plant visit reports, sampling and analysis reports, and engineering analysis. Its major
limitations include data that are sometimes more than 15 years old and the coverage of only selected
industries.
The third data source was information gathered by EPA's Office of Water in preparing
Effluent Guidelines Development Documents. These data are summarized in OSW's Capacity
Analysis Background Document for the Phase HI LDR.1 The data describe the composition of non-
hazardous industrial wastewaters generated by major industry groups. These wastewater data are of
varying age, and therefore their continued representativeness is unclear. Also, the number of analytes
in the database is quite limited. As seen below, a very high proportion of the waste constituents
identified in this source also are identified in one or both of the two data sources described above.
Thus, the effluent guidelines data serve mainly to confirm data from the other sources.
The Agency also reviewed two recent proposed listing decisions for hazardous wastes, those
for solvent wastes and for wastes from the dyes and pigments industries. Several additional chemicals
were identified as being constituents of unlisted (non-hazardous) solvent waste streams that were not
found in any of the other data sources: 2-methoxyethanol, 2-ethoxyethanol acetate, cyclohexanol,
isophorone, and diethylamine.2 No non-hazardous industrial waste constituents from the dyes and
pigments industry were identified, because all of the data concerning the compositions and generation
rates of these wastes were held as confidential by the industries that submitted data.3
Excluding TC analytes, which are addressed in Chapter 3, a total of 146 chemicals were
identified in the release descriptions, 183 in the ISDB, and 19 in the effluent guidelines data. An
additional five unique constituents were found in the listings background document. Overall, a total of
250 unique chemicals were identified.
The chemicals and waste constituents identified in the three data sources are sorted into major
chemical classes and shown in Exhibit 4-2. These constituents span a wide range of chemical classes.
Even with a number of possibly redundant entries, the most common category of chemicals was metals
and inorganics, with 48 chemicals. Other prominent families of chemicals included volatile
chlorinated organics (38), other semivolatile organics (46), other volatile organics (45), and pesticides
and related compounds (29). Included among the chlorinated organics are several trihalomethanes and
two chlorofluorocarbons. The "other semivolatile" category contains a wide range of compounds,
many of which are found only in the ISDB data. The pesticides category contains mostly chlorinated
organic pesticides and intermediates, but also contains some nonchlorinated compounds.
1 U.S. Environmental Protection Agency, Office of Solid Waste, Background Document for Capacity
Analysis for Land Disposal Restrictions Phase III - Decharacterized Wastewaters. Carbamate Wastes, and Spent
Potliners (Final Rule). Volume 1, February, 1996.
2 U.S. Environmental Protection Agency, Office of Solid Waste, Assessment of Risks from the Management
of Used Solvents (Draft), May 3, 1996.
3 U.S. Environmental Protection Agency, Office of Solid Waste, Listing Background Document: Final
Hazardous Waste Listing Determination for the Dyes and Pigments Industries. November 30, 1994, non-
confidential business information version.
Page 4-5
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I
-------
Less prominent categories of chemicals include the PAHs (18 compounds), volatile
hydrocarbons (12), phenolic compounds (8), and phthalate esters (6). The PAHs range from low-
molecular weight, noncarcinogenic compounds (such as naphthalene) to the higher molecular weight
carcinogens and mutagens (such as benzo(a)pyrene). All but one of the volatile hydrocarbons
(styrene) are commonly found as constituents in kerosene, gasoline, and related fuels. Styrene is a
monomer used in plastics production. The phenolic compounds include creosote components (cresols)
and two nitrophenols. Most of the phthalate esters are found in all the first three data sources,
including the suspect carcinogen bis-(2-ethylhexyl)-phthalate. Polychlorinated biphenyls (PCBs) and
chlorinated dioxins (represented by 2,3,7,8-TCDD) were found in the ISDB.
The number of compounds in the various categories does not necessarily reflect the relative
potential importance of the chemicals or categories. As noted above, some chemicals occur only in
one database, while others occur in two, three, or all four. In addition, some chemicals occur in more
than one release description, that is, at more than one facility, or are identified as waste constituents
from more than one industry group. Except for the chemicals in the release descriptions, there is no
indication of the relative concentrations of the chemicals in wastes.
Given the wide range of chemical classes represented in the lists, and the relatively small total
number of non-TC chemicals in the four datasets (250), the Agency found no convincing reason to
eliminate any candidate chemicals from inclusion in the gaps analysis. Given that lexicological and
fate and transport data are available for most of these chemicals, all the chemicals were carried
forward for further analysis.
4.3 Identify Possible Non-Hazardous Industrial Waste Constituents of Potential Concern
This section describes the approach to identifying additional chemicals that might constitute
potential gaps in the hazardous waste characteristics. Unlike the previous analysis, which began with
four relatively narrow and specific data sources, this analysis begins with a wide range of data sources,
in order to avoid excluding chemicals of potential concern. Subsequently ? a substantial proportion of
the large universe of chemicals are screened out on the basis of toxicity, fate and transport
characteristics, and potential for occurrence in waste. A large portion also could not be evaluated
because of a lack of data. The result is a focused list of possible non-hazardous industrial waste
constituents that could pose significant risks to human health or the environment. The list of possible
non-hazardous industrial waste constituents supplements the list of known non-hazardous industrial
waste constituents developed in the previous section.
4.3.1 Approach to Identifying Potentially Hazardous Chemicals
Excluding TC analytes, EPA identified over 2,300 distinct chemicals from 36 regulatory and
advisory lists originally created by EPA, other federal agencies, state and national regulatory agencies,
and special environmental task forces and advisory bodies. Exhibit 4-3 identifies these lists. The
RCRA regulatory lists included are the 40 CFR 261 Appendix VII and VJQI lists of hazardous waste
constituents, the proposed HWIR-Waste Chemicals, and the HWIR-Media "Bright Line" chemicals.
Other major federal regulatory lists include the Clean Water Act Section 307 Toxic Pollutants and
Section 311(b)(2) Hazardous Substances, the CERCLA list of hazardous substances with reportable
quantities, the Emergency Planning and Community Right-to-Know (EPCRA) Toxic Chemicals and
Extremely Hazardous Substances lists, the Clean Air Act Amendments Section 112(b) Hazardous Air
Pollutants and Section 112(r) Regulated Toxic Substances, and chemicals for which OSHA has
published Permissible Exposure Limits (PELs). The U.S. Department of Transportation (DOT)
Page 4-7
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Exhibit 4-3. Lists Used to Identify Possible Non-Hazardous Industrial Waste Constituents
RCRA Section 3001 Hazardous Waste, 40 CFR Part 261, Appendix VII
RCRA Section 3001 Hazardous Waste, 40 CFR Part 261, Appendix Vffl
CWA Section 307 Toxic Pollutants
CWA Section 311(b)(2)(A) List of Hazardous Substances
CERCLA Hazardous Substances Reportable Quantity List
CAA Section 112(b) Hazardous Air Pollutants
CAA Section 112(r) Regulated Toxic Substances
HWIR-Media (Bright-Line) Chemicals
HWTR-Waste Chemicals
HWIR-Waste Ecotoxicity Chemicals
OSHA Permissible, Exposure Limits for Chemicals
EPCRA Section 302 Extremely Hazardous Substances
EPCRA Section 313 Toxic Chemicals List
Industrial Studies Data Base
Canada's Toxic Substances Management Policy
Canadian ARET Toxics Scoring Protocol (A1-A2 LISTS)
Canadian ARET Toxics Scoring Protocol (Bl LIST)
Canadian ARET Toxics Scoring Protocol (B2 LIST)
Canadian ARET Toxics Scoring Protocol (B3 LIST)
Chemicals on Five or More Lists for Short-Term Exposure
Criteria to Identify Chemicals for Sunsetting in Great Lakes Basin
Deferred Toxicity Characteristic Chemicals
Effluent Guidelines Chemicals
Potential Endocrine Disrupters
EPA Hazardous Substance Task Force (Levels 1 and 2)
FIFRA Active Ingredients
Focus Chemicals for the Great Waters Study (USEPA 1991)
Great Lakes Water Quality Agreement Standard Methods Chemicals
Highly Flammable Chemicals (Based on Several Lists)
Highly Reactive Chemicals (Based on Several Lists)
Michigan Critical Materials Register
Persistent Bioaccumulative Chemicals Screening
Proposed Water Quality Guidance, Great Lake Systems (1994)
UN ECE Task Force on Persistent Organic Pollutants (1993)
University of Tennessee Chemical Ranking System (1994)
DOT Hazardous Materials Transportation Act, Hazardous Materials Regulations3
Notes:
a Data base searched manually.
Page 4-8
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Hazardous Materials Transportation Act (HMTA) Hazardous Materials Registry (HMR) also was used
to identify potential gap chemicals, but could not be directly included in the database in time because
of format differences in the available machine-readable forms of the list.
Some of the advisory lists that were included are the 1992 EPA Hazardous Substance Task
Force's4 Level 1 and Level 2 hazardous chemicals that were identified as not being controlled under
RCRA or DOT regulations, the Focus Chemicals for the Great Waters Study,5 chemicals identified by
Environment Canada under the ARET Toxics Scoring Protocols, chemicals identified by the University
of Tennessee Chemical Ranking System, and the Michigan Critical Materials Register. Some lists
address specific types of hazards, such as potential endocrine disrupters, acutely toxic chemicals,
highly flammable chemicals, and highly reactive chemicals. Brief descriptions of the lists and the
selection criteria that were applied to derive them are provided in "Background Document:
Identification of Chemicals from Regulatory and Advisory Lists Representing Potential Gaps in the
Hazardous Waste Characteristics."6
Naturally, there is a high degree of overlap among the chemical lists. Some lists are subsets
of, combinations of, or otherwise derived from other lists. Nonetheless, the chemicals identified
represent a very broad spectrum of potential hazards. High-volume and highly toxic chemicals appear
on many lists, as do acutely toxic, flammable, and reactive chemicals. Several lists specifically seek to
include carcinogens, mutagens, and teratogens. Some lists are derived based on considerations of
ecotoxicity, persistence, and bioaccumulation potential, or based on specific environmental media or
geographical concerns. The overall goal in the Scoping Study was to identify the broadest possible set
of chemicals of potential concern, and then to screen them down to the chemicals with the highest
potential to pose risks to human health or the environment.
4.3.2 Screening Approach
EPA performed the hazard-based screening of potentially hazardous constituents in two steps.
First, the entire list of chemicals was screened against criteria related to toxicity to humans and aquatic
organisms and separately against various fate and transport criteria. Chemicals for which data were
not available for at least one of these criteria were not included in further analysis. In the second step,
EPA took all of the chemicals identified as either highly toxic, mobile, persistent, or bioaccumulative
and first screened them against the proxy for occurrence in waste, namely the TRI release data. Any
chemical passing this screen has a high potential for occurrence in waste and was identified as a
possible non-hazardous industrial waste constituent. Chemicals were also retained in the analysis if
they were not on the TRI list. Only the chemicals confirmed as having low releases through the TRI
data were eliminated from being possible constituents.
The criteria considered for use in screening (both the possible constituents described in this
section and the combined lists discussed in Section 4.4) are summarized in Exhibit 4-4. These criteria
were derived using professional judgment to provide a reasonable level of discrimination between
4 U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, Report of the
EPA Hazardous Substances Task Force. April 1992.
5 U.S. Environmental Protection Agency, Office of Air Quality, Planning and Standards, Deposition of Air
Pollutants to the Great Waters. First Report to Congress. Publication EPA-453/R-93-055, May 1994.
6 U.S. Environmental Protection Agency, Office of Solid Waste, November 15, 1996.
Page 4-9
-------
Exhibit 4-4
Criteria Considered for Screening Non-Hazardous Industrial Waste Constituents3
Parameter
Cutoff Value
Rationale
I. Toxkity Values
OralRfD
OralCSF
Inhalation RfC
Inhalation UR
Primary MCL
Acute AWQC
Chronic AWQC
<1.3xlO'2 -. mg/kg-day 50th percentile
Any Value
>2.9xlO-1 (mg/kg-day)-1
3.3xlO'4 (ug/m3)'1
<5xlO"2 mg/1
<130 mg/1
<5.2 mg/1
All Suspect Carcinogens
50th percentile
50th percentile
All Suspect Carcinogens
50th percentile
50th percentile
50th percentile
50th percentile
II. Fate and Transport Parameters
Fish BCF >1,000
Fish BAF >1,000
Kow >100,000
Beef Biotransfer >7.8xlO"3
Vegetable Root CF >15
Forage BCF >3.5
Henry's Law Constant (kH) >lx!0'5
Vapor Pressure >1.3xlO"2
Air-Leafy Plant Factor >5.3xlO'4
Air Half Life >0.15
Soil Deg. Constant <0.5
Water Deg. Constant <0.5
I/kg
I/kg
(unitless)
day/kg
(ug/gm)/(ug/gm)
(ug/gm)/(ug/gm)
atm-M3/mole
atm
(ug/gm)/(ug/gm)
years
year
.-1
year
.-i
About 85th percentile, lists range from 500-100,000
About 50th percentile, lists range from 500-15,000
About 75th percentile, lists range from 10,000-
1,000,000
75th percentile
75th percentile
75th percentile
50th percentile, moderately volatile
About 70th percentile = 1 mm Hg
75th percentile
75th percentile
About 75th percentile, DAF risk reduction = lOOx
About 75th percentile, DAF risk reduction = lOOx
. Indicators of Possible Occurrence in Waste
1994 TRI Release Data >106 Ibs.
[994 Production Data >106
(TSCA Inventory Update)
Ibs.
Includes 99 percent of all releases to air, water,
and land (including underground injection)
Indicates potential for widespread use, occurrence
in waste and release potential
All of these criteria were considered for use in the screening of both the possible non-hazardous industrial
waste constituents and the combined lists discussed in Section 4.4. As discussed in the text, only a subset of
these criteria ultimately were used.
Page 4-10
-------
chemicals with relatively high-hazard potential and those with lower potential. For most toxicity
parameters, which were available only for a relatively small number of more toxic chemicals, the
cutoff values were set at the 50th percentile of the entire range of values. For many fate and transport
parameters, the criteria were set at or around the 75th percentile (or 25th percentile, if a low value
implied high hazard potential) of the entire range of the parameter values for all of the chemicals for
which the parameter was available. In some cases, the screening criteria were set at levels generally
recognized as indicative of hazard potential.
In the course of the Scoping Study, many different criteria for and approaches to the screening
process were evaluated; the background document to this Study provides further detail.7 The criteria
and approach described in this section is a relatively simple one that evolved from those previous
efforts. One of the major lessons learned in that work was that screening is inherently imprecise, and
no single screen will catch or exclude all the chemicals desired. Another lesson learned is that
screening large lists against complex criteria can quickly become very complicated, and the return on
the complexity, in terms of useful information, can be quite low. Therefore, EPA has focused on a
relatively small number of criteria that are important in determining risk potential and has critically
interpreted the results of the screening.
In the case of carcinogens, two sets of criteria were used. The first set indicates whether a
cancer slope factor (CSF) had been promulgated for the chemical. The second indicates whether an
inhalation unit risk (UR) had been developed. These criteria identified the bulk of human carcinogens.
For noncarcinogenic effects, two sets of criteria again were used. The first indicates whether an
ingestion reference dose (RfD) had been developed at a sufficiently toxic level for the purposes of this
analysis (i.e., below the 50th percentile). The second indicates whether an inhalation Reference
Concentration (RfC) had been developed below the 50th percentile. For aquatic effects, the 50th
percentile of the Chronic Ambient Water Quality Criteria (AWQC) was used.
EPA used several criteria to screen fate and transport properties. The screening criteria for the
fish bioconcentration factor (BCF) and bioaccumulation factor (BAF) were both set at 1,000 I/kg, the
beef biotransfer factor was set at 7.8xlO"3 day/kg, and the octanol-water partition coefficient (Kow)
was set at 105. These four values indicate the potential for the chemicals to be taken up and/or
accumulated by organisms. The vapor pressure criterion, used as a proxy for volatilization release,
was set at 1 mm Hg. A Henry's Law constant (kH) value of 10"5 atm-m3/mole was also used to
identify chemicals with high volatilization potential. The criterion used to identify persistent chemicals
in soil or water (degradation rate constant less than 0.5/year) was selected based on an analysis of the
EPACMTP findings for organic pollutant transport in groundwater, which indicated that, at rate
constants above this value, the calculated DAF values begin to differ substantially from those for non-
degrading pollutants with similar properties.8
As noted in Section 3.5, the screening-level risk analysis also was used to identify screening
criteria and their importance. For example, Henry's Law constants were found not to be a good
indicator of the potential for long-term volatilization releases, so that the parameter is not used as a
primary screening factor (although it is examined briefly in the next section). Instead, vapor pressure
7 Background Document: Identification of Chemicals from Regulatory and Advisory Lists Representing
Potential Gaps in the Hazardous Waste Characteristics, supra footnote 6.
8 U.S. Environmental Protection Agency, Office of Solid Waste, EPACMTP Background Document for
Finite Source Methodology for Chemical with Transformation Products. Chapter 6, 1995.
Page 4-11
-------
is used to screen chemicals for volatilization release. Even this screen must be interpreted cautiously,
however, since chemicals with low vapor pressures can still volatilize from treatment units if no other
processes are occurring to limit the releases.
The primary data source that is used as a proxy for occurrence of hazardous chemicals in non-
hazardous industrial wastes is the release data, reported under the Emergency Planning and
Community Right-to-Know Act (EPCRA) Toxic Release Inventory (TRI) requirements. For purposes
of the screening conducted for this study, EPA considered those chemicals with releases to air, land,
water, and underground injection exceeding one million pounds in 1994. Under EPCRA Section 313,
facilities with more than 10 full-time employees that are classified in SIC codes 20 through 39 (i.e.,
manufacturing) must submit reports if they manufacture or process more than 25,000 pounds of a TRI
chemical or otherwise use more than 10,000 pounds of a TRI chemical in a given calendar year.
There were a total of 73 unique chemicals and 10 classes of chemicals in this category, out of the 345
individual chemicals for which reports are required. These chemicals account for greater than 99.8
percent of the total TRI releases of all chemicals. As discussed in Section 4.4.2, the combined list of
known and possible non-hazardous industrial waste constituents were also screened against non-CBI
1994 production data from the TSCA Inventory.
A major limitation of this screening approach is that quantitative toxicity and fate and transport
parameter values were available for only a fraction of the over 2,300 non-TC chemicals identified.
Human toxicity parameters were available for just over 430 chemicals, ambient water quality data for
105 chemicals, and complete fate and transport data for 194 chemicals. For this reason, the screening
approaches were supplemented by searching lists that identify chemicals presenting specific types of
hazards, even if no quantitative parameter value was available, and by applying professional judgment
to identify where potential risk findings for individual chemicals may be generalized to broader classes
of chemicals. The results of this screening are described in a background report (see footnote 6).
4.3.3 Toxicity, Fate, and Transport Screening for Possible Non-Hazardous Industrial
Waste Constituents
Exhibit 4-5 summarizes the results of the screening for possible non-hazardous industrial waste
chemicals against the toxicity criteria. The first two columns indicate the chemicals that are suspect or
known human carcinogens having ingestion CSFs or inhalation URs. The last three columns identify
the chemicals with oral RfDs, inhalation RfCs, and AWQCs below the 50th percentile of these
parameter values (a low value indicates high toxicity) for all chemicals for which these values have
been developed. Note that this table does not include TC analytes or chemicals previously identified
as known non-hazardous industrial waste constituents.
As noted previously, the number of chemicals identified on all 37 lists of chemicals is much
greater than the numbers of chemicals for which toxicity parameters have been developed.
Furthermore, the list of chemicals, which includes practically all of the known chemicals from Section
4.2 and all of the TC analytes, includes almost all chemicals for which these toxicity values have been
derived. Thus, the lexicological screen has the potential9 to screen out most of the possible non-
hazardous industrial waste constituents simply because most of the constituents do not have toxicity
values, and therefore the effectiveness of the individual toxicity screening criterion is substantially
9 Toxicological criteria only have a potential to screen out chemicals because, as discussed below, chemicals
may be considered high hazard (for the purposes of this analysis) because of fate and transport characteristics.
Page 4-12
-------
Exhibit 4-5. Toxicity Screening Results for Possible Non-Hazardous
Industrial Waste Constituents
Chemicals with CSFs
2,4,6-Trinitrotoluene
3,3'-Dichlorobenzidine
4,4'-Methylenebis(N,N-dimethyl)benzenamine
Acephate
Aramite
Azobenzene
Benzidine
Bis(2-ethylhexyl) adipate
Bis(chloromethyl) ether
Cyclotrimethylene trinitramine
Dichlorvos
Folpet
Fomesafen
Furmecydox
Hexachlorocyclohexane
Hexachlorodibenzo p dioxin, mixture (HxCDD)
N-Nitrosodi-n-butylamine
N-Nitrosodi-n-propylamine
N-Nitrosodiethanolamine
N-Nitrosodiethylamine
N-Nitrosomethylethylamine
N-Nitrosopyrrolidine
Prochloraz
Propylene oxide
Trifluralin
Chemicals with Unit Risks
1,3-Butadiene
Aramite
Asbestos (friable)
Azobenzene
Benzidine
Bis(chloromethyi) ether
Hexachlorocyclohexane
HxCDD
N-Nitrosodi-n-butylamine
N-Nitrosodiethylamine
N-Nitrosopyrrolidine
Nickel subsulfide
Propylene oxide
Chemicals with Low RfDs
(50th percentile)
1,1,2 Trichloropropane
1,2,4 Tribromobenzene
1,3,5-Trinitrobenzene
1,3 Phenylenediamine
1,4 Dibromobenzene
1,4 Dithiane
2-Chloropheno!
2-Cyclohexyl-4,6-dinitrophenoi
2,3 Dichloropropanol
2,4,5-T acid
2,4,6-Trinitrotoluene
2,4-DB
2,6-Dimethylphenol
3,4 Dimethylphenol
Acephate
AcetataJdehyde, trichloro-
Acifiuoren, sodium salt
Alachlor
Aldicarb sulfone
Aluminum phosphate
Ametryn
Amitraz
Avermectin B1
Bentazon
Benzidine
Bis(tributyltin) oxide
Captafal
Carbamottiioic acid, dipropyl-S-propyi ester
Carfaosulfan
Chlorpyrifos
Cyclotrimethylene trinitramine
Cyhalothrin
Decabromodiphenyl oxide
Demeton
Dichlorvos
Dicrotophos
Dinftrobutyl phenol
Diquat
Diuron
Dodine
EPN
Ethion
Ethylene thiourea
Fenamiphos
Flometuron
Fluvalinate
Fonofos
Glufosinate ammonium
Glycidylaldehyde
Haloxyfop methyl
Page 4-13
-------
Exhibit 4-5. Toxicity Screening Results for Possible Non-Hazardous
Industrial Waste Constituents (continued)
Low RfDs (continued)
(<50th percentile)
Hexabromobenzene
Hexachlorophene
Hydramethylnon
Imazalil
Lactofen
Linuron
Maneb
Mecoprop
Mercuric chloride
Merphos
Methacrylonitrile
Methamidophos
Methidathion
Methoxone
Methyl mercury
Mirex
N,N-Dimethylaniline
Naled
NuStar
Octabromodiphenyl ether
Oxydiazon
Oxyfluorfen
Parquat dichloride
Pentabromodiphenyl ether
Phenylmercuric acetate
Primiphos methyl
Prochloraz
Prometryn
Prop'achlor
Propanil
Propargyl alcohol
Propiconazole
Propoxur
Quinalphos
Quintozene
Quizalofop-ethyl
Rotenone, commercial
S,S,S-Tributyltrithiophosphate
Selenious acid
Simazine
Sodium azide
Sodium fiuoroacetate
Strychnine
Terbacil
Terbutryn
Tetraethyl lead
Thallium chloride TICI
Thallium(l) acetate
Thallium(l) carbonate
Thallium(l) nitrate
Thallium(l) sulfate
Thiobencarb
Triallate
Tribenuron methyl
Trifluralin
Warfarin
Zinc phosphide
Low RfCs
(50th Percentile)
2-Chloroacetophenone
Antimony trioxide
Arsine
Chlorine dioxide
Dichlorvos
Hexamethylene-1,6-diisocyanate
Methylenebis(phenylisocyanate)
Toluenediisocyanate (mixed
isomers)
Triethylamine
Vinyl bromide
Low AWQCs
(50th percentile)
Azinphos-methyl
Chlorpyrifos
Demeton
Malathion
Mirex
Page 4-14
-------
limited for a large proportion of the chemicals identified on the 37 lists. Nevertheless, because all
chemicals with cancer toxicity values are considered high hazard for this portion of the analysis, no
chemicals would be screened out on the basis of carcinogenicity.
The toxicity screening reduced the number of chemicals dramatically from the original
universe of over 2300. As noted above, this reduction is primarily a function of the relatively small
number of chemicals (about 400) for which human or ecotoxicity data are available. The screened list
contains about one-third (25/74) of the chemicals for which CSFs were available, and about one-
quarter (13/52) of those for which inhalation unit risks are available. The chemicals with low (<50th
percentile) RfDs comprise by far the largest (107) set of all the chemicals identified by the toxicity
screening, representing about one-third of the total number of chemicals for which RfDs have been
derived. A large proportion of these chemicals are pesticides. Relatively few chemicals were
identified having low inhalation RfCs and AWQCs for aquatic life.
Exhibit 4-6 summarizes the results of the screening of chemicals with regard to fate and
transport properties. The first two columns address the potential to volatilize for soil and water, as
indicated by the vapor pressure and Henry's Law constant. Since these parameters are directly related,
the chemicals in these two columns overlap substantially. The next column lists chemicals with soil or
water column degradation constants less than 0.5/year. Since the values for these two media are close
for most of the chemicals, separate columns are not provided for each medium. The final three
columns identify the chemicals with relatively high aquatic BCFs, beef biotransfer factors, or Kows.
Since all three of these values are related to partitioning between lipid and water phases, the chemicals
in these three columns also overlap substantially.
As was the case for the toxicity screens, consistently-derived fate and transport parameters are
not available to screen the majority of the chemicals. Thus, the menu of chemicals that are identified
by the screening criteria related to each individual parameter again is determined primarily by the
availability of data. In the case of the fate and transport screening, fewer chemicals are identified as
being potentially hazardous. In addition, the fate and transport screening identifies a smaller
proportion of the chemicals for which data are available. In all cases, the chemicals exceeding the
screening criteria represent less than 10 percent of the chemicals for which data are available.
4.3.4 Release Volume Screening of Possible Non-Hazardous Industrial Waste
Constituents
Chemicals not screened out by the toxicity or fate and transport criteria were screened against
the 1994 TRI data (used as a proxy for occurrence in wastes). The results of this final screening are
presented in Exhibit 4-7. Of the 151 unique chemicals or classes of chemicals that were identified in
the toxicity or fate and transport screening, TRI release data were available for 24 of them. Five of
these chemicals (Freon 113, 1,3-butadiene, chlorine dioxide, chloroprene, and propylene dioxide) had
TRI releases above one million pounds in 1994. Nineteen of the chemicals had TRI releases less than
a million pounds. This latter group of chemicals were eliminated from further analysis. As noted
previously, the remaining 132 chemicals for which no TRI data were available were retained in the
analysis.
Page 4-15
-------
Exhibit 4-6. Persistence and Bioconcentration/Bioaccumulation Screening Results
for Possible Non-Hazardous Industrial Waste Constituents
Vapor Pressure > 1.3xlO'3
atm
Henry's Law Constant > 10"5
atm-m3/mole
SoilAVater
Degradation Rate
Constant < 0.5
years
.-1
2-Chlorophenol
Chloroprene
cis-l,3-Dichloropropene
Ethyl methacrylate
Freon 113
Methacrylonitrile
N-Nitrosodi-n-propylamine
N-Nitrosodiethylamine
N-Nitrosomethylethylamine
2-Chlorophenol
Bis(2-chloroisopropyl) ether
Chloroprene
cis-1,3-Dichloropropene
Dinitrobutyl phenol
Ethyl methacrylate
Freon 113
Methacrylonitrile
N-Nitrosodi-n-butylamine
N-Nitrosodi-n-propylamine
Quintozene
Safrole
Tris(2,3-dibromopropyl) phosphate
3-Methylcholanthrene
Kepone
Quintozene
Fish BCF > 1,000 I/kg
3-Methylcholanthrene
Chlorobenzilate
Diallate
Diethylstilbestrol
Kepone
Beef Biotransfer Factor
> 7.8X10"4
3-Methylcholanthrene
Diethylstilbestrol
Hexachlorophene
Kepone
Quintozene
Kow > 10s
3-Methylcholanthrene
Diethylstilbestrol
Hexachlorophene
Kepone
Page 4-16
-------
EXHIBIT 4-7 SCREENING OF HIGH-TOXICITY, PERSISTENT, BIOACCUMULATIVE/BIOCONCENTRATING
POSSIBLE NON-HAZARDOUS WASTE CONSTITUENTS AGAINST TRI RELEASE VOLUMES
Chemical CAS
3000076-13-1
30001 06-99-0
5010049-04-4
30001 26-99-8
0000075-56-9
0000101-68-8
30001 03-23-1
0001163-19-5
)001 332-21 -4
30001 26-98-7
3026471-62-5
3000092-87-5
3000121-69-7
3001 582-09-8
3000593-60-2
3000082-68-8
0000062-73-7
0002164-17-2
0000096-45-7
3012427-38-2
3000542-88-1
3000091-94-1
0000114-26-1
0000070-30-4
0000133-07-3
0000126-72-7
0000122-34-9
0000121-82-4
0000140-57-8
0000141-66-2
0000143-50-0
0000131-89-5
0000576-26-1
0000709-98-8
0000621-64-7
0000616-23-9
0000615-54-3
0000330-55-2
0000598-77-6
0000150-50-5
0000563-68-8
0000563-12-2
0000532-27-4
0000510-15-6
0000505-29-3
0000330-54-1
0000300-76-5
0000608-73-1
0000078-00-2
0000088-85-7
Chemical Name
Freon 113
1.3-Butadiene
Chlorine dioxide
Chloroprene
Propylene oxide
Methylenebis(phenylisocyanate)
Bis(2-ethylhexyl) adipate
Decabromodiphenyl oxide
Asbestos (friable)
Methacrylonitrile
Toluenediisocyanate (mixed isomers)
Benzidine
N,N-Dimethylaniline
Trifluralin
Vinyl bromide
Quintozene
Dichlorvos
Fluometuron
Ethylene thiourea
Maneb
Bis(chloromethyl) ether
3,3'-Dichlorobenzidine
Propoxur
Hexachlorophene
Folpet
Tris(2,3-dibromopropy1) phosphate
Simazine
Cyclotrimethylene trinitramine
Aramite
Dicrotophos
Kepone
2-Cyclohexyl-4,6-dinitrophenol
2,6-Dimethylphenol
Propanil
N-Nitrosodi-n-propylamine
2,3 Dichloropropanol
1 ,2,4 Tribromdbenzene
LJnuron
1 ,1 ,2 Trichloropropane
Merphos
Thallium(l) acetate
Ethion
2-Chloroacetophenone
Chlorobenzilate
1,4Dithiane
Diuron
Naled
Hexachlorocydohexane
Tetraethyl lead
Dinitrobutyl phenol
Release
Volume
5,077,542
2,711,287
1,501,041
1,157,755
1,076,879
846,938
844,594
469,811
294,368
80,802
50,695
31,606
22,676
15,304
2,620
2,558
1,286
832
529
272
255
10
4
.
Oral CSF
Inhalation Unit Risk
| Oral RfD < 50th
| Rf C < 50th
I AWQC (Chronic) < 50th
| Degradation Rate for Water Column
I Fish BCF
| Henry's Law Constant
1
*
1 Soil Degradation Rate
1 Vapor Pressure > 1_3e-3
| Beef Biotransfer Factor >7_8e-4
Page 4-17
-------
EXHIBIT 4-7 (CONTINUED)
SCREENING OF HIGH-TOXICITY, PERSISTENT, BIOACCUMULATIVE/BIOCONCENTRATING
POSSIBLE NON-HAZARDOUS WASTE CONSTITUENTS AGAINST TRI RELEASE VOLUMES
3000108-45-2
3000086-50-0
3000085-00-7
3000083-79-4
3000121-75-5
3000078-48-8
0000093-65-2
3000075-87-6
3000062-74-8
3000062-38-4
3000057-24-9
3000056-53-1
3000056-49-5
0000056-35-9
3000081-81-2
3000101-61-1
3000121-44-8
3000118-96-7
0000765-34-4
3000107-19-7
3000924-16-3
3000087-82-1
3000103-33-3
3000093-76-5
3000099-35-4
3000097-63-2
0000095-65-8
0000095-57-8
3000094-82-6
3000094-74-6
0000094-59-7
0000106-37-6
0022967-92-6
0033089-61-1
0000822-06-0
0032534-81-9
0030560-19-1
0029232-93-7
0028249-77-6
0012035-72-2
0025057-89-0
0035554-44-0
0022224-92-6
0020859-73-8
0019666-30-9
0019408-74-3
0015972-60-8
0013593-03-8
0000834-12-8
0026628-22-8
Chemical Name
Walathion
S.S.S-TributyltrithioDhosphate
Acetaldehyde. trichloro-
'henylmercuric acetate
Diethvlstilbestrol
3-Methylcholanthrene
3is(tributyttin) oxide
Warfarin
4.4'-Methytenebis(N.N-dimethvl)benzenamine
Triethylamine
2.4.6-Trinitrotoluene
3lvcidvlaldehyde
Propargyl alcohol
N-Nitrosodi-n-butylamine
Hexabromobenzene
Azobenzene
2.4.5-Tacid
1 .3.5-Trinitrobenzene
Ethyl methacrvlate
3.4 Dimethyjphenol
2-Chlorophenol
2.4-DB
Methoxone
Safrole
1 .4 Dibromobenzene
Methyl mercury
Amftraz
Hexamethylene-1 ,6-diisocyanate
PentabromodiDhenvl ether
Acephate
Pirimiphos methyl
Thiobenoarb
Nickel subsulfide
Bentazon
Imazalil
Fenamiphos
Aluminum phosphide
Oxydiazon
Hexachlorodibenzo p dioxin, mixture (HxCDD)
Alachlor
Quinalphos
Ametiyn
Sodium azide (Na(N3))
Release
Volume
Oral CSF
| Inhalation Unit Risk
I Oral RfD < 50th
t/
«/
*
»/
I/
I/
I/
s/
«/
6/
!/
*
in
V
»/
| AWQC (Chronic) < 50th
i/
| Degradation Rate for Water Column
^
j Fish BCF
f
i/
| Henry's Law Constant
^
*
*
i
**
j Soil Degradation Rate
j Vapor Pressure > 1_3s-3
«/
/
j Beef Blotransfer Factor >7_8e-4
Page 4-18
-------
EXHIBIT 4-7 (CONTINUED)
SCREENING OF HIGH-TOXICrTY, PERSISTENT, BIOACCUMULATIVE/BIOCONCENTRATING
POSSIBLE NON-HAZARDOUS WASTE CONSTITUENTS AGAINST TRI RELEASE VOLUMES
Chemical CAS
)067747-09-5
3085509-19-9
3077501-63-4
0077182-82-2
3076578-14-8
0072178-02-0
0069806-40-2
3032536-52-0
3068085-85-8
0039638-32-9
3067485-29-4
3065195-55-3
3062476-59-9
3060568-05-0
3060207-90-1
0055285-14-8
3042874-03-3
0069409-94-5
3001314-84-7
0002385-85-5
3002303-16-4
3002104-64-5
3001929-77-7
0001918-16-7
0001646-88-4
3002425-06-1
3001309-64-4
3001116-54-7
0000950-37-8
0000944-22-9
0000930-55-2
0101200-48-0
0000886-50-0
0000055-18-5
0001910-42-5
0007791-12-0
0010595-95-6
0010265-92-6
0010102-45-1
0002303-17-5
0008065-48-3
0002439-10-3
0007784-42-1
0007783-00-8
0007487-94-7
0007446-18-6
0007287-19-6
0006533-73-9
0005902-51-2
0002921-88-2
0010061-01-5
Chemical Name
3rochloraz
MuStar
.actofen
3lufosinate ammonium
Duizalofop-ethyl
-omesafen
Haloxyfop methyl
Dctabromodiphenyl ether
Dyhalothrin
3is(2-chloroisopropyl) ether
Hydramethylnon
Avermectin B1
Acifluorfen, sodium salt
rurmecyclox
Propiconazoie
Darbosulfan
Dxyfluorfen
Fluvalinate
Zinc phosphide
Vlirex
Diallate
EPN
Carbamothioic acid, dipropyl-, S-propyl ester
Propachlor
Aldicarb sulfone
Captafol
Antimony trioxide
N-Nitrosodiethanolamine
Methidathion
Fonofos
N-NitrosoDvrrolidine
Tribenuron methyl
Terbutryn
N-Nitrosodiethvlamine
Paraquat dichloride
Thallium chloride T1CI
N-Nitrosomethylethylamine
Methamidophos
Thallium(l) nitrate
Triallate
Demeton
Dodine
Arsine
Selenious acid
Mercuric chloride
Thallium(l) sulfate
Prometryn
Thallium(l) carbonate
Terbacil
Chlorpyrifos
cis-1 ,3-Dichloropropene
Release
Volume
i
Oral CSF
t/
Inhalation Unit Risk
Oral RfD< 50th
**
1_3e-3
I Beef Biotransfer Factor >7_8e-4
Page 4-19
-------
4.3.5 Summary of Possible Non-Hazardous Industrial Waste Constituents
Exhibit 4-8 summarizes the results of the TRI screening process. It places the possible non-
hazardous waste constituents into the same chemical categories as were used to characterize the known
non-hazardous industrial waste constituents in Exhibit 4-2. The largest number of possible waste
constituents (74) are pesticides and related compounds. As discussed in Section 4.3.2, these chemicals
are identified as being potentially hazardous primarily by virtue of low RfDs, although there are also
some potent ecotoxins, as well as persistent and bioaccumulative chemicals, among this group.
The next most numerous category among the possible constituents are the other semivolatile
organic chemicals. This diverse group includes chemicals recognized both for their toxicity and their
fate and transport properties. Twelve metals/inorganic elements or groups are identified including five
different thallium salts. Similarly, the other volatile organics group includes 5 nitrosamines among a
total of 13 compounds. Also included in this group are two very toxic organometallic compounds,
methyl mercury and tetraethyllead. Among the seven chlorinated organics are two of the five
chemicals with TRI releases greater than one million pounds (Freon 113 and chloroprene). No other
chemical category is represented by more than five chemicals.
4.4 Combine and Screen Known and Possible Non-Hazardous Industrial Waste Constituents
In this section, the known (from Section 4.2) and possible (from Section 4.3) non-hazardous
industrial waste constituents are combined and screened against toxicity, fate, and transport criteria.
Unlike the prior section, screening is oriented more toward groups of chemicals rather than toward
individual chemicals, and toward comparing the properties of known versus possible non-hazardous
industrial waste constituents. There is, in addition, another screening step related to potential for
occurrence in wastes, namely, comparison to 1994 non-confidential TSCA production volume data.
4.4.1 Combine the Lists
The lists of known and possible non-hazardous industrial waste constituents are shown in
Exhibits 4-2 and 4-8. Exhibit 4-9 summarizes the screening of the known non-hazardous industrial
waste constituents hi the same way that Exhibit 4-7 provides these data for the possible constituents.
As seen in these exhibits, the distribution of chemicals within chemical classes is somewhat different
between the known and possible non-hazardous industrial waste constituents. These differences,
however, are exaggerated by the removal of the known constituents from consideration as possible
constituents. (Logically, a chemical cannot be both a "known" and "possible" waste constituent.) The
known non-hazardous industrial waste constituents are distinguished by a relatively high proponion of
metals and inorganics, chlorinated volatile organics, other volatile organics, and polycyclic aromatic
hydrocarbons, compared .to the possible non-hazardous waste constituents. In contrast, pesticides and
related compounds constitute a much higher proportion of the possible non-hazardous industrial waste
constituents than the known constituents.
The pattern of differences in chemical category can be partially explained by the differences in
the data sources. The relatively high prominence of volatile organics among the possible constituents
probably reflects the difficulties in controlling fugitive releases of these high-volume chemicals during
storage and processing. Such chemicals are somewhat less likely to turn up in groundwater samples
(in the release descriptions or in aqueous effluents) because of their high volatility. The prominence
of the less volatile organics in the known non-hazardous industrial waste constituents again reflects the
greater stability of these chemicals in solid and liquid wastes.
Page 4-20
-------
I
EXHIBIT 4-* POSSIBLE NON-HAZARDOUS INDUSTRIAL WASTE CONSTITUENTS BY CHEMICAL CLASS
IMMi/lrargtnlci
AnftnonylilouMi
knlnt
MoamqiuUa
Umgnot
Mtmirtccttortda
id
IMtonlDcaitoMl.
ThtfKimMnllraia
Haiinii(l)»uHil»
nnc
12'
VolitlrtCMorinllK!
i Ofgmlei
.l,2TitcHoiotifOMna
'.aOUHaaeaxaaa
Acalalifetiyds.tilcMMo-
UtB-cHwolMcnipvB «Uw
cte-l.a-DtcMMomopona
'i«ontl3
VdiUto
Hydroccritoti
.3 BuHdHna
1
OtlwVolilll«Orjinlc«
l.4Pmil«ne
Aiotuniena
ilycolElhOT
Methyl mercuiv
N-NilnMoJ-n-bulvtemlne
NNHrtBodnpfoovlaiiilne
N-NBngodtelhinolamlna
Prooigylitaihol
reltaemyllsatl
13
PtiilcldMAnurmvdIilrafltogfi
8.4-DB .
rilluortan. sodium tall
Auditor
Cailelct
CaitMmollilolc add, dlwocvl-, S-pmpyl oslor
ChtoTobenzHalo
Dltllile
Kqual
JocHne
PN
Ethton
f4exacMorocvdohex&ne
75
detlon Products
Lfmiion
MatatMoo
"fl'Phos
MethtdatNon .. 1
jNuSlar j
Paraquat dJchlorida
3ulnatphos
^uizalofop-ethyl
S.S.S-TttbuIvllritWoohosDhalQ
Strychnine
reftacf)
UVailarin
Zinc phoSpMde
Phenolic Compound*
2-Cvdohoxvt-4.G-diniHophenol
3.4 Dimethylphenol
Dinilrobutyl phenol
5
Polycyctlc Aromatic
Hydrocubons
1
Other Semtvolaille Organic*
,3.5-TiinitrobenzQno
2.4.6-Trinltrotohiene
.-J'-MelhvlooobisfN.N-dimelhvDbenzenamlne
AvetmectinBI
dethvlstilbeslrol
GlvcWvlaWehydo
'ropfconazofa
20
Notes:
1. All thallium sails are counted as one entiy.
-------
EXHIBIT 4-9 SCREENING OF KNOWN NON-HAZARDOUS WASTE CONSTITUENTS AGAINST TRI RELEASE VOLUMES
Chemical CAS
0000067-56-1
0000108-88-3
0001330-20-7
0000075-15-0
0000075-09-2
0000100-42-5
0000071-55-6
0000071-36-3
0000108-10-1
0000050-00-0
0000075-05-8
0000075-07-0
0000100-41-4
0000064-18-6
0007440-66-6
0007439-96-5
0000079-10-7
0000107-13-1
0000079-06-1
0000074-87-3
0000075-71-8
0000091-20-3
0000074-90-8
0000075-69-4
0000074-83-9
0000080-62-6
0007440-50-8
0000098-82-8
0000062-53-3
0007440-02-0
0000078-87-5
0000098-86-2
0000117-81-7
0000123-91-1
0000106-89-8
0000084-74-2
Chemical Name
Methanol
Toluene
Xylene (mixed isomers)
Carbon disulfide
Zinc compounds
Dichloromethane
Glycol Ethers
Copper compounds
Manganese compounds
Styrene
1 ,1 ,1 -Trichloroethane
n-Butyl alcohol
Methyl isobutyl ketone
Formaldehyde
Acetonitrile
Acetaldehyde
Ethylbenzene
Formic acid
Zinc
Manganese
Acrylic acid
Acrylonitrile
Acrylamide
Chloromethane
Dichlorodifluoromethane
Cyanide compounds
Naphthalene
Hydrogen cyanide
Trichlorofluoromethane
Bromomethane
Methyl methacrylate
Copper
Cumene
Aniline
slickel compounds
Antimony compounds
Nickel
,2-Oichloropropane
Acetophenone
Di(2-ethylhexyl) phthalate
,4-Dioxane
Epichlorohydrin
Dibutyl phthalate
Release
Volume
255,766,934
168,958,68'
108,936,037
83,384,729
81,764,72(
63,774,566
48,991,927
47,115,33!
41,504,786
40.156.84J
38.056,89-
30,081,146
25,501,571
19,755,895
18,264,05*
13,052,16£
12,802,135
11,267,572
10,155,445
9,354,55!:
6,915,166
6,379,861
5,217,625
5,174,937
4,872,594
4,382,505
3,230,142
3.143,252
2,994,474
2,669,788
2,583,587
2,204,032
2,057,269
1,976,326
1,665,815
1,445,522
988,468
713,383
699,062
560,325
538,929
490,967
353,193
Oral CSF
Inhalation Unit Risk
Oral RfD< 50th
RfC < 50th
Beef Blotransfer Factor >7_8e-4
AWQC (Chronic) < 50th
Degradation Rate for Water Column
Fish BAF
Fish BCF
Henry's Law Constant
(/
&
Soil Degradation Rate
Vapor Pressure > 1_3e-3
Page 4-22
-------
EXHIBIT 4-9 (CONTINUED)
SCREENING OF KNOWN NON-HAZARDOUS WASTE CONSTITUENTS AGAINST TRI RELEASE VOLUMES
Chemical CAS
0000079-00-5
0000095-50-1
0000110-80-5
0000107-18-6
0000107-05-1
0000120-82-1
0000107-02-8
0007440-36-0
0000099-65-0
0000074-95-3
0007723-14-0
0007440-62-2
0000079-46-9
0000051-28-5
0000542-75-6
0007440-41-7
0000075-34-3
0000100-44-7
0000106-93-4
0000302-01-2
0000120-83-2
0000079-34-5
0000630-20-6
0000077-47-4
0000111-44-4
0000137-26-8
0000098-07-7
0000056-38-2
0007440-28-0
0000075-27-4
0000086-30-6
0001336-36-3
0000096-18-4
0000095-94-3
0000096-12-8
0000156-60-5
0000122-66-7
0000058-90-2
0001746-01-6
0000057-97-6
0000083-32-9
0000067-64-1
0000116-06-3
0000309-00-2
0000959-98-8
0000319-84-6
Chemical Name
1 ,1 ,2-Trichloroethane.
1 ,2-Dichlorobenzene
2-Ethoxyethanol
Ally! alcohol
Ally! chloride
1 ,2,4-Trichlorobenzene
Acrolein
Antimony
m-Dinitrobenzene
Methylene bromide
Phosphorus
Vanadium (fume or dust)
2-Nitropropane
2,4-Dinitrophenol
1 ,3-Dichloropropylene
Beryllium
Ethylidene Dichloride
Benzyl chloride
1 ,2-Dibromoethane
Hydrazine
2,4-Dichlorophenol
1 ,1 ,2,2-Tetrachloroethane
1,1,1 ,2-Tetrachloroethane
Hexachlorocydopentadiene
Bis(2-chloroethyl) ether
Thiram
Benzoic trichloride
Parathion
Thallium
Dichlorobromomethane
N-Nitrosodiphenylamine
Polychlorinated biphenyls
1 ,2,3-Trichloropropane
1,2,4,5-Tetrachlorobenzene
1 ,2-Dibromo-3-chloropropane
1 ,2-Dichloroethylene, trans
1 ,2-Diphenylhydrazine
2,3,4,6-Tetrachlorophenol
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)
7,12-Dimethylbenz[a]anthracene
Acenaphthene
Acetone
Aldicarb
Aldrin
alpha - Endosulfan
alpha-Hexachlorocyclohexane
Release
Volume
311,036
275,148
227,691
211,963
201,493
184,280
170,087
128,663
100,719
77,545
50,768
41,023
40,523
39,344
24,756
23,795
23,492
23,331
18,537
16,956
14,760
14,027
11,746
9,174
3,237
3,184
2,868
1,147
1,010
0
0
0
it.
CO
O
1
O
Inhalation Unit Risk
Oral RfD< 50th
RfC<50th
Beef Biotransfer Factor >7_8e-4
AWQC (Chronic) < 50th
Degradation Rate for Water Column
Fish BAF
Fish BCF
Henry's Law Constant
i
Soil Degradation Rate
Vapor Pressure > 1_3e-3
Page 4-23
-------
EXHIBIT 4-9 (CONTINUED)
SCREENING OF KNOWN NON-HAZARDOUS WASTE CONSTITUENTS AGAINST TRI RELEASE VOLUMES
Chemical CAS
3000056-55-3
0000218-01-9
0000050-32-8
3000205-99-2
0033213-65-9
0000319-85-7
0000075-25-2
0000085-68-7
0001563-66-2
3000124-48-1
3018540-29-9
3000156-59-2
0008007-45-2
0000544-92-3
0000057-12-5
0000072-54-8
0000072-55-9
0000050-29-3
0000053-70-3
0000060-57-1
0000060-51-5
0000298-04-4
0000115-29-7
0000060-29-7
0000141-78-6
0000206-44-0
0000086-73-7
0000110-00-9
0000098-01-1
0007783-06-4
0000193-39-5
0000078-83-1
0000078-59-1
0000298-00-0
0002212-67-1
0007439-98-7
0000117-84-0
0000062-75-9
0000106-47-8
0000608-93-5
0000298-02-2
0007803-51-2
0000129-00-0
0003689-24-5
0010061-02-6
0001314-62-1
Chemical Name
Benz[a]anthracene
Benzo(a)phenanthrene
Benzo[ajpyrene
Benzo[b]fluoranthene
beta - Endosulfan
beta-BHC
Bromoform
Butyl benzyl phthalate
Carbofuran
Chlorodibromomethane
Chrom!um(VI)
cis-1 ,2-Dichloroethylene
Coal tars
Copper cyanide
Cyanides (soluble salts and complexes)
ODD
DDE
DDT
Dibenz[a,h]anthracene
Dieldrin
Dimethoate
Disulfoton
Endosulfan
Ethane, 1 ,1 '-oxybis-
Ethyl acetate
Fluoranthene
Fluorene
Furan
Furfural
Hydrogen suffide
lndeno(1 ,2,3-cd)pyrene
Isobutyl alcohol
Isophorone
Methyl parathion
Molinate
Molybdenum
n-Dioctyiphttialate
N-Nitrosodimethylamine
p-Chloroaniline
Pentachlorobenzene
Phorate
Phosphine
Pyrene
Sulfotep
trans-1 ,3-Dichloropropene
Vanadium pentoxide
Release
Volume
Oral CSF
X
CO
z
s:
s
c
_o
"5
JS
c
Oral RfD < 50th
RfC<50th
Beef Blotransfer Factor >7_8e-4
V
| AWQC (Chronic) < 50th
| Degradation Rate for Water Column
V*
i/
| Fish BAF
| Fish BCF
Henry's Law Constant
&
§
X
V
^
v>
i/
| Soil Degradation Rate
I Vapor Pressure > 1_3e-3
Page 4-24
-------
Exhibit 4-9 also shows that the known waste constituents include a much higher number of
chemicals with TRI release values greater than one million pounds (45)10 than is found among the
possible constituents (5). This is primarily due to the fact that the known waste constituents were
identified first. Many of the high TRI release chemicals also would have been identified as possible
non-hazardous industrial waste constituents if they had not been identified as known constituents. The
implications of these findings for the potential severity of gaps in the hazardous characteristics are
discussed in more detail in Chapter 10.
In the analysis that follows, the known and possible non-hazardous industrial waste constituent
lists are combined, and screened against single and multiple parameters related to toxicity, fate and
transport, and release potential.
4.4.2 Screen Combined List Against Single Criteria
Quantitative Human Toxicitv Indicators. Exhibit 4-10 summarizes the lexicological properties
of the combined known and possible non-hazardous industrial waste constituents. The chemicals are
screened using the same criteria as described for the possible constituents alone in Section 4.3, with
the exception that additional criteria related to carcinogenic potency are added (oral CSF and
inhalation UR > 50th percentile). The list of suspect carcinogens (i.e., the first and third columns in
Exhibit 4-10) contains a large proportion of all chemicals for which EPA has developed CSFs and
URs. The proportion of the chemicals with high CSFs or URs (i.e., the second and fourth columns) is
likewise very near to one-half of the total suspect carcinogens. This finding indicates that, as
expected, the large universe of chemicals initially screened contains almost all of the chemicals that
EPA has evaluated as potential human carcinogens. Many classes of chemicals (inorganics, volatile
chlorinated organics, pesticides, other volatile chemicals) are represented among the suspect
carcinogens.
Ecotoxicity. As shown in the last column of Exhibit 4-10, 18 of the combined known and
possible constituents have low AWQCs (below 50th percentile), indicating the potential for adverse
effects on aquatic organisms. Many of these chemicals are pesticides, and most of the pesticides are
persistent chlorinated pesticides. Although most of these chemicals are no longer produced, their
presence among the known non-hazardous industrial waste constituents may give rise for some
concern. Also included in this group are selenium, silver, and hydrogen sulfide.
Potential Endocrine Disniptors. Because of the rapidly-evolving state of knowledge regarding
chemicals that may act as endocrine disrupters, estrogen inhibitors, or have other hormone-like effects,
it is difficult to estimate precisely how many of the combined known and possible non-hazardous
industrial waste constituents fall into this category. Based on the rather broad list of potential
endocrine disrupters,11 23 of the combined constituents are implicated as being potential endocrine
disrupters (Exhibit 4-11). (Nine of the TC analytes are also potential endocrine disrupters.) Because
of the lack of knowledge concerning dose-response relationships for exposures to single and multiple
10 This number includes both unique compounds (e.g., ethylbenzene) and categories of compounds (e.g.,
antimony compounds).
11 The list of endocrine disrupting chemicals was developed based on information from Colborn, T.,
F.S. Saal, and A.M. Soto, 1993, "Developmental Effects of Endocrine-Disrupting Chemicals in Wildlife and
Humans," Environmental Health Perspecdves. 101:378-384, October 1993; and Warhurst, M., 1996, Introduction
to Hormone Disrupting Chemicals, on the. World Wide Web at http://www.ed.ac.uk/~amw/oestrogenic.html.
Page 4-25
-------
I
tnh*tatlQfiUnttftfiJi(AJfy
1. 1 .2.2>T«UachIor o*thvxi
1.1.2-TikWcx«ito*na
t,2-EWxomc*m»n«
I .Z'Dohonyfhvdf ufno
1.3'Buttdieiw
Ac«l*Wfflhydo
AcrytamWe
Afckln
o4p}»'Hoxactilorocyclohoxan«
beia-BHC
8:$(2*chlofoe(hyl) Qlhw
Bis(chtoromethvt) alher
CoaUats
DDT
Dtthtaomethane
OieWrin
Eptchlorohydiln
Hffixachforodibonzopdk>x*n mixture (HxCDO)
KytfraziiTO
N-Nrtrosopyitolkfino
Nickel subsullido
EXH
5Wh PwcwiUt*
Acrytwnide
AWrirt
iJph*-H«XiCttofocytWitxano
StnzWioa
Bwjifium
txHl-BHC
Qis[2-chtoroelhy1)emof
Coal lw a *
Drald/in
HtaachlofocyctohoKantt
HxCDO. mixture
Hydrtitoe
M-NHrosodi-n-butyfamkio
N-Nitrosodtalhyljmino
^NtlioswJtmeihytamino
H-Nrttosopyrrolidkio
Niche) sub3UI1.de
err 4-10 Toxtcrrv suuMAny OF KNOWN A
OrilCSF(AI)
l.1.2.2-Tolf»chto(OflHiano
1.1.2-TrichkHMtrmno
K2-D*Momo&lhano
l^-Diphftnylhydrazino
1.4>Dioxtn«
2.3.7.D-Tetrachtoiod*Gnio-p-*0)(in (FCOD)
2.4,6SWhPtrcinll!i
1.2 Ch6/omoQiIian«
1 .2-OphonyHiydf arr»o
2.3.7.8°1CDD
Acrylarnvto
Aciytomltile
Aldrm
a'pha-Hox3chtofOCyck)Jioxano
BenzoIalpyrGne
BonzoicltichtoTida
Beryllium
bola-BHC
QistZ-cMoroelhyl) ethor
DDE
DOT
Diolddn
Hexachlorocyclofiexano
HxCDD. mixluro
Hydrazine
^Nilfosodi-n-bulylamino
N-Nilfosodi-n-propylamine
NJ-Nitrosodmlhanolamine
F4-NitrosodielhyIamifio
J-Nittosod/nelhylainino
N-Nilrosomelhytelhylamtne
M-Nttrosopyrrolidine
Polychlorinaled bfphenyls
Vinylidene chloride
US INDUSTRIAL WASTE CONSTITUEHTS
Oral RID < SOIh Ptrctnlllt
1.1.2 IncWoropiopano
1.1.2- Fhchtoroolhana
1.2.3'TrJchtoiopropanQ
1.2.4 Tribfomobenzono
1 ,2.4.5*T0!rachIoi obenzcne
1 .2.4 -Titchtor obenzeno
1 .3.5-Iitnitroben iona
1 ,3'DichloropiopytQ no
1.3-Phonylenedtamine
1.4 Dibfooiobenzeno
1.4Dflhjano
2.3 Dichtoropiopanol
2.4.5-T acid
2.4.6*T(Ini!roIoltione
2.4-DB
2.4'Dichtorophenol
2.4'DiniUophenol
2.G-DimethyIpheno!
2-Chtoiophono!
2-CydohexyM.6-dintUophenol
3.4 Oimelhylphonot
Acephale
Acolatdehyde. Irichloro-
AcQlonilfile
AcIIIuoifen. sodium sail
Acrylamide
Alachlor
Aldicaib
Wdicaib suHone
Aldrin
Allyl alcohol
Aluminum phosphide
Ametryn
Amitraz
Antimony
Avoimoclin B1
Benlazon
Beryllium
3is(lhbulyltki) oxide
Bromomelhans
Captatol
Carbamolhioic acid, dtpropyN. S-propyl ester
Carbofuran
Carbosullan
Chlorpyiitoc
Copper cyanide
CyctotrimQthylene Irtnilramine
Cyhatolhrin
DDT
Demeton
Dtcrotophos
Dioldnn
Dimelhoale
Dinilrobulyl phenol
Diqual
Disulloton
Dturon
Dodine
Endosul'an
EPN
Elhion
Fcnamiphos
"urfutal
Oral RID < 50th PtrcanUl*
jlyctdytoidetiyda
lexabr omoboniene
iQxachloroQthano
lydiamcthylnon
-fydiogen sullidQ
Lactoten
^ocoprop
Uercuiic chloride
Uerphos
Wolhamidophos
Methtdalhion
Methyl mercury
Methyl paralhion
Mtrex
Motinate
Molybdenum
Mated
MuSlar
Octabfomodiphenyl ether
Oxydiazon
Dxylluoiten
p-Chloroanittne
Paraquat dichloride
Penlabromodiphenyl ether
Penlachlorobenzena
Phosphine
Phosphorus
Pirtmiphos methyl
Prochloraz
Propachlor
Propanit
S.S.S'Tfibutyltrithtophosphate
'-:>niousactd
1 . -.me
;»,-,iumazideJNa(N3))
Slrychnine
Sutrotop
Taibacil
Terbultyn
Tetraelhyt lead
Thallium chloride TICI
Thallium(l) carbonate
rhallium(l) nitrate
Thallium(l) sullate
Thtobencarb
Fhiram
Hiatlate
Warfarin
AWQC (Chronic FrtthwKir) <
2.3.7.8-ICUD
\nlvnony
\iinpnos-moihy1
>cla * Endosullan
^hlorpyrilos
Copper
3DT
^alalhkui
^ftex
-------
Exhibit 4-11
Potential Endocrine Disrupters
Known and Possible Constituents
2,3,7,8-tetrachlorodibenzodioxin (2378-TCDD)
2,4,5-trichlorophenoxyacetic acid (2,4,5-T)
alachlor
aldicarb
b-hexachlorocyclohexane (b-BHC)
butylbenzylphthalate (BBP)
DDD
DDE
DDT
dibromochloropropane (DBCP)
dibutyl phthalate (DBF)
dieldrin
diethylhexyl phthalate (DEHP)
dimethyl phthalate (DMP)
dioctyl phthalate (DOP)
endosulfan
mirex
parathion
polychlorinated biphenyls (PCBs)
polychlorinated dibenzodioxins (PCDDs)
styrene
TC Analvtes
cadmium
heptachlor and heptachlor expoxide
lead
lindane
mercury
methoxychlor
pentachlorophenol (PCP)
toxaphene
endocrine disraptors, it is difficult to predict if these chemicals would present risk to humans and non-
human receptors. Nevertheless, the fact that so many of these chemicals are present among the
constituents may cause concern.
Potential for Frequent Occurrence in Wastes. The combined list of known and possible non-
hazardous industrial waste constituents were also searched to identify those chemicals with high
potential for occurrence in wastes, as indicated by TRI releases and/or non-confidential TSCA
Inventory production data. The results of this analysis are summarized in Exhibit 4-12. Constituents
are included in the table only if either TRI release data or non-CBI TSCA inventory data are available
for them.
Volatility and Persistence. As discussed in Section 3.5, volatility and persistence appear to be
key indicators of potential risks for the TC analytes. In the first four columns of Exhibit 4-13, the
known and possible non-hazardous industrial waste constituents are screened against these properties.
Vapor pressure of 1.3xlO~3 atmosphere (which is approximately equivalent to 1 mm Hg) is used to
identify volatile chemicals. This measure approximates the potential to volatilize; many chemicals
with lower vapor pressure could volatilize readily under certain waste management conditions. Even
so, 70 known of possible non-hazardous industrial waste constituents fall into this category. This
Page 4-27
-------
EXHIBIT 4-12 TRI RELEASES AND NON-CONFIDENTIAL TSCA PRODUCTION VOLUME DATA FOR
THE KNOWN AND POSSIBLE NON-HAZARDOUS INDUSTRIAL WASTE CONSTITUENTS
Chemical CAS
0000071-55-6
0000079-00-5
0000095-63-6
0000107-06-2
0000542-75-6
0000075-07-0
0000075-05-8
0000079-06-1
0000079-10-7
0000107-13-1
0007429-90-5
0007664-41-7
0000062-53-3
0000071-43-2
0000074-83-9
0000075-15-0
0000056-23-5
0007782-50-5
0000108-90-7
0000075-00-3
0000067-66-3
0000074-87-3
0007440-47-3
0007440-50-8
0008001-58-9
0001319-77-3
0000098-82-8
0000075-71-8
0000075-09-2
0000100-41-4
0000107-21-1
0000050-00-0
0000064-18-6
0000067-72-1
0000074-90-8
0007664-39-3
0007439-96-5
0000067-56-1
0000078-93-3
0000108-10-1
0000080-62-6
0000071-36-3
0000091-20-3
0000095-47-6
0000106-42-3
0000108-95-2
0000127-18-4
000007941-6
000007549-4
0000108-05-4
0000075-01-4
0001330-20-7
0007440-66-6
0000106-99-0
0000576-26-1
0001332-21-4
0010049-04-4
0000126-99-8
0000121-82-4
0000076-13-1
0000075-56-9
Chemical Name
1 .1 ,1-Tnchloroethane
1.1,2-Trichloroethane
1 .2.4-Trimethylbenzene
1 .2-Dichloroethane
1 ,3-Dichloropropylene
Acetaldehyde
Acetonitnle
Acrylamide
Acrylic acid
Acrylonitrile
Aluminum (fume or dust)
Ammonia
Aniline
Antimony compounds
Benzene
Bromomethane
Carbon disulfide
Carbon tetrachloride
Chlorine
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chromium
Copper
Creosote
Cresol (mixed isomers)
Cumene
Cyanide compounds
Dichlorodifluoromethane
Dichloromethane
Ethylbenzene
Ethylene glycol
Formaldehyde
Formic acid
Glycol Ethers
Hexachloroethane
Hydrogen cyanide
Hydrogen fluoride
Hydrogen sulfide
Manganese
tfetnanol
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
n-Butyl alcohol
Naphthalene
Nickel compounds
>-Xylen»
Phenol
richloroethylene
Trichlorofluorometnane
Vinyl acetate
Vinyl chloride
Xylene (mixed isomers)
Zinc
1.3-Butadiene
2,6-Dim ethyl phenol
Asbestos (friable)
Chlorine dioxide
Zhloroprene
Cydotrimethylene trinitramine
=reon113
1 994 THI Release
Volume > 1 million Ibs.
Known Chemicals
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
>OMibl« Chemical*
X
X
X
X
X
1994 Non-Confidential TSCA
Production Volume > 1 million Ibs.
X
X
X
X
CBI
X
X
X
X
X
X
X
X
X
x
Page 4-28
-------
EXHIBIT 4-13 VOLATIL
Vapor Pretiura>
1.3«-3alm.
1 . 1 . 1 ,2-Tetrachlofoe thane
1.1,1-Tfichloroelhane
1.1,2,2-Tetrachloroethano
1.1.2-TrfchtofoeUiaro
1 ,2,3-Trlchloropropane
1 .2-Dibromoethane
1.2-Dlchkxobenzena
1,2-Dlchloroethylene. trans
1 ,2-DfchkHOpropan8
1,3-Dldiloropropytone
1.4-Dioxane
2-Chlorophenol
2-Elhoxyathanol
2-Nilropropana
Acetone
Acetofiilrile
Acroteln
Acrykmttrile
Ally! chloride
Benzyl chloride
Bls(2-cWoroethyl) ether
Bromotorm
Bromornelhane
Carbon dlsutlido
Chtorodibromomelhane
Chloromelhane
Chloroprene
cls-1 .2-Dichloroettiyl8ne
cls-1,3-Dlchk>ropropene
Cumene
DIchkHobromomelhane
Dichtorodifiuorome thane
Dichlorofnethane
Eptehlorohydrin
Ethane. 1,1'-oxybls-
Ethyl acetate
Ethyl methacrylate
Ethylbenzene
Ethylktene DlchlorkJe
Formaldehyde
Formic acid
Freon 113
Furan
Isobutyl alcohol
Melhanol
Methyl Isobutyl ketone
Methyl methacrylate
Melhytene bromide
n-Butyt alcohol
N-N!lrosodi-n-propylamlne
N-Nilrosodlethylamine
N-Nilrosodlmelhylamlne
N-Nitrosomethylelhylamine
j-Chkxoanlllno
Styrene
Toluene
trans-1 .3-Dtchloropropene
rrichtorofluoiomethana
Vinylidene chloride
Xylene (mixed isomers)
.*««««».
Air Halt-Life >
75th Percenllle
Dtehtofomethane
Polychlorlnated biphenyls
BIOACCUMULATION/BIOCONC
Low Soil/Water Degradation
Constant (< 0.5)
1,2-Dlchloropropane
2.3.7.8-TCDD
3-Melhylcholanlhrene
Atdrin
Antimony
Benz[a)anthracene
Benzo10*
2,3,7,8-TCDD
3-Methylcholanthrene
7.12-Dimelhytbenz|a]anthracene
Aldrin
Benz[a)anlhracene
Benzo(a)phenanlhrene
Benzo[a]pyrene
Benzo[b]lluoranlhene
ODD
DDE
DDT
Di(2-elhylhexyl) phthalale
Dibenz[a,h]anlhracene
Dieldrin
Dielhylstilbeslrol
Fluoranlhene
Hexachlorocyclopentadiene
lndeno(t,2,3-cd)pyreno
Kepone
n-Dioctylphlhalale
Penlachlorobenzene
Polychlorinaled biphenyls
Pyrena
IAL OF KNOWN AND POSSIBL
High Fish BAF (>1000)
1 ,2,4,5-Tetrachlorobenzene
alpha-Hexachlorocyclohexane
bola-BHC
DDE
DDT
E NON-HAZARDOUS INDUS
High Fish BCF (>1000)
2.3,4,6-Telrachlorophenol
3-Melhylcholanlhrene
Aldrin
Bulyl benzyl phlhalate
CHorobenzilale
DDD
Diallale
Dibulyl phlhalate
Dieldrin
Dielhylstilbeslrol
Hexachlorocyclopenladiene
Kepone
Penlachlorobenzene
TRIAL WASTE CONSTITUENTS
Beef Blotransler Factor > 7.8e-4
1 ,2.4,5-Tetrachlorobenzene
2.3.7,8-TCDD
3-Melhylcholanlhrene
7, 1 2-Dimelhy!ben2(a|anthraceiie
Aldrin
Antimony
Benzjalanthracene
Benzo(a)phenanlhrene
Benzo|a)pyrene
Benzo[b|lluoranlhene
Beryllium
Bulyl benzyl phlhalate
Copper
DDD
DDE
DDT
Dl(2-ethylhexyl) phlhalate
Dibenz[a,h]anlhracene
Dibutyl phlhalate
Dieldrin
Dielhylslilbeslrol
Fluoranlhene
Hexachlorocyclopentadiene
Indenof 1 ,2.3-cd)pyrene
Kepone
Molybdenum
n-Dioctylphlhalale
Nickel
Pentachlorobenzene
Polychlorinated biphenyls
Pyrene
Thallium
Vanadium (fume or dust)
Page 4-29
-------
finding suggests that, as for the volatile TC analytes, volatilization releases and inhalation exposures
(and possibly indirect exposures) may be a concern for some of these chemicals.
Two chemicals, both chlorinated organics, are identified as having long half-lives (greater than
0.15 year) in air. This finding does not mean that all of the other constituents are too short-lived to be
of concern through air exposures. Half-lives on the order of a few hours or days also may be of
concern in terms of direct inhalation exposures. This criterion is more indicative of the potential for
long-range (e.g., regional or global-scale) transport of these chemicals in the vapor phase. Also, as
noted in Section 3.5, the air half-lives of many of the inorganic waste constituents (especially the
metals) bound to particulates would also be limited only by how long the particles remained suspended
in the atmosphere.
The third column of Exhibit 4-13 identifies the non-hazardous industrial waste constituents that
are relatively persistent either in soils or in the water column. The metals all fall into this category,
along with the PAHs, many chlorinated pesticides, and 2,3,7,8-TCDD. The only volatile organic
chemical in this category is 1,2-dichloropropane. Appearance in this category arouses concern for
potential inhalation and indirect pathway exposure risks, as discussed in Section 3.5.
A high Kow, as indicated in the fourth column, indicates a high potential to bind to soil
organic matter. It is highly correlated with the tendency to bioaccumulate. Thirty-one of the known
and possible waste constituents including many persistent pesticides and PAHs, are in this category.
Bioaccumulation Potential. The last three columns of Exhibit 4-13 indicate the potential for
bioaccumulation by the known -and possible non-hazardous industrial waste constituents in aquatic and
terrestrial food chains. The constituents with aquatic BCFs or BAFs greater than 1,000 are limited to
the chlorinated pesticides, several phthalate esters, and diethylstilbestial (DBS). This finding does not
imply that no other constituents present significant risks through indirect pathways; nevertheless, the
identified chemicals are all clearly recognized as being problematic from the point of view of
bioconcentration. If these chemicals were released in significant amounts from non-hazardous waste
industrial management activities, they could present substantial risks through food-chain exposures.
The last column of the table lists chemicals that are taken up from feed by beef cattle with
above-average (greater than 75th percentile) efficiency. This list includes most chemicals that also are
of potential concern for aquatic ecosystems. Also, several additional classes of chemicals are
identified, including the metals and PAHs. Although the beef biotransfer factor is only one of many
parameters determining the potential for risks to humans from beef consumption, it is a reasonable
indicator of potential concern for this pathway and is a useful indicator of exposure potential in other
terrestrial food chains.
LNAPL and DNAPL Formation. The potential to form nonaqueous phase liquids (NAPLs) is
of great concern from the point of view of waste management risks. Historically, NAPLs have been
serious problems in the remediation of hazardous waste, because of their high potential risks and high
remediation costs. Any chemical that is relatively insoluble in water and is a liquid at ambient
temperature can be the principal component of a NAPL. If the chemical or chemical mixture is denser
than water, then a dense nonaqueous phase liquid (DNAPL) is formed. If the liquid is less dense than
water, a light nonaqueous phase liquid (LNAPL) may be formed.
Page 4-30
-------
DNAPLs are of particular concern because, when they escape to groundwater, they will sink
through the unsaturated zone or aquifer until they encounter bedrock or another barrier. They can
remain at the bottom of the aquifer (for example, in bedrock fractures) where they are hard, or in some
cases nearly impossible, to remediate. Most DNAPLs undergo only limited degradation in the
subsurface, and persist for long periods while slowly releasing soluble organic constituents to
groundwater. Even with a moderate DNAPL release, dissolution may continue for hundreds of years
or longer under natural conditions before all the DNAPLs are dissipated and concentrations of soluble
organics in groundwater return to background levels. When released into surface water, DNAPLs tend
to sink to the bottom and contaminate sediments. LNAPLs, in contrast, will tend to float on the
surface of an aquifer, where they are easier to remedy; yet, they also can contaminate large volumes of
groundwater through slow dissolution. Both LNAPLs and DNAPLs also can facilitate the transport of
toxic waste constituents by solubilizing chemicals that would otherwise be immobile in waste or soil
matrices.
It is difficult to predict the circumstances under which LNAPL and DNAPL formation will
occur and pose a risk to human health or the environment. Whether significant amounts of NAPLs
will form depends on the composition of the wastes and the management practices employed. Reports
of nonaqueous phase liquids were not found among the release descriptions for non-hazardous
industrial waste management summarized in Chapter 2, possibly due to limitations in monitoring
requirements. EPA has recently conducted a study of the potential for DNAPL formation at hazardous
waste (NPL) sites, and identified several industries where NAPL formation is particularly likely to
occur.12 These industries include wood treating sites, general manufacturing, organic chemical
production, and "industrial waste landfills". A wide variety of chemicals have been found in NAPLs,
and it appears that if a chemical is to be the major constituent of a NAPL, the most important
requirements are relative insolubility in water and liquidity at ambient temperatures.
Exhibit 4-14 identifies a number of the known and possible non-hazardous industrial waste
constituents with the requisite physical properties. Since there is no clear dividing line between
chemicals likely and not likely to form NAPLs, this list was developed using a combination of
professional judgment and information about the physical properties of the waste constituents. All of
the chemicals listed are organics, have relatively low water solubilities, and are liquid at room
temperature (melting points greater than 7°C, boiling point greater than 30°C). Those indicated as
being potential DNAPL formers have bulk liquid densities greater than 1 gm/cc, while those with
densities less than water are indicated as potential LNAPL formers. The distinction is not clear-cut
however, as a mixture of light and heavy constituents at different relative concentrations might have
widely varying densities.
Exhibit 4-14 identifies more potential DNAPL formers than LNAPL formers found among the
known and possible waste constituents. Based on density considerations, the LNAPL formers tend to
be primarily the non-halogenated hydrocarbons, including "BTEX"13 and compounds with similar
properties, whereas the DNAPL formers tend to be primarily chlorinated and brominated chemicals.
Not included in the NAPL list are pesticides that also fulfill the physical criteria, but which are no
longer produced (see Chapter 9) and thus are less likely to be present in significant amounts in pure
form in non-hazardous industrial wastes. These findings suggest that, on physical bases alone, many
12
U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, Evaluation of the
Likelihood of DNAPL Presence at NPL Sites. EPA 540-R-93-073, September 1993.
13 BTEX refers to benzene, toluene, ethylbenzene, and xylene, which are common constituents of gasoline.
Page 4-31
-------
Exhibit 4-14
LNAPL/DNAPL Formation Potential of Known
and Possible Non-Hazardous Industrial Waste Constituents
Chemical Name
1,1,1 ,2-Tetrachloroethane
1,1,1 -Trichloroethane
1 , 1 ,2-Trichloropropane
1 , 1 ,2,2-Tetrachloroethane
1,1 ,2-Trichloroethane
1 ,2,3-Trichloropropane
1 ,2-Dibromo-3-chloropropane
1 ,2-Dibromoethane
1 ,2-Dichlorobenzene
1,2-Dichloroethylene, trans
1 ,2-Dichloropropane
1 ,3-Dichloropropylene
2,3-Dichloropropanol
2,3,4,6-Tetrachlorophenol
2,4-Dichlorophenol
2-Chloroacetophenone
Acetophenone
Allyl chloride
Benzyl chloride
Bromoform
Butyl benzyl phthalate
Carbon disulfide
Chlorodibromomethane
NAPL Type3
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
L
L
L
D
D
D
D
D
Chemical Name
Chloropropene
cis- 1 ,2-Dichloroethy lene
cis- 1 ,3-Dichloropropene
Cumene
Di(2-ethylhexyl) phthalate
Dibutyl phthalate
Dichlorobromomethane
Diethyl phthalate
Dimethyl phthalate
Ethylbenzene
Ethylidene Bichloride
Freon 113
Hexachlorocyclopentadiene
n-Dioctylphthalate
N-Nitrosodi-n-propylarnine
p-Chloroaniline
Propylene oxide
Safrole
Styrene
Toluene
trans- 1 ,3-Dichloropropene
Trichlorofluorpmethane
Xylene (mixed isomers)
NAPL Type3
D
D
D
L
L
D
D
D
D
L
D
D
D
L
L
D
L
L
L
L
D
D
L
Notes:
a D = DNAPL (density of pure compound > 1.0 gm/cc)
L = LNAPL (density of pure compound < 1.0 gm/cc)
of the known and possible non-hazardous industrial waste constituents could form LNAPLs or
DNAPLs. As noted above, however, when this actually occurs depends to a large degree on the
specific characteristics of the wastes and waste management practices.
EPA's analysis of DNAPL formation at NPL sites found that the contaminants most directly
associated with DNAPL presence include creosote compounds, coal tar compounds, polychlorinated
biphenyls (PCBs), chlorinated solvents, and mixed solvents.14
14 U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, Evaluation of the
Likelihood of DNAPL Presence at NPL Sites. EPA 540-R-93-073.
Page 4-32
-------
4.4.3 Screen Combined List Against Multiple Parameters
This section discusses the results of one last round of screening conducted on the entire
combined list of known and possible non-hazardous industrial waste constituents. This analysis
combines toxicity, persistence, volatility, and bioaccumulation screens in various combinations in order
to identify the chemicals most likely to pose risks by various exposure pathways. Only constituents in
the intersections of the screens remain (e.g., only constituents that are persistent and highly toxic). For
human toxicity, the criteria have been "applied in the following order:
Persistent and Highly Toxic to Humans. This combination is intended to
identify highly toxic chemicals that could pose risks through any pathways
involving long-term release and transport of contaminants, such as groundwater
and indirect pathways involving air, surface water, or groundwater releases.
Persistent. Highly Toxic to Humans and Bioaccumulative. This screen narrows
the above waste constituents to those with potential for adverse effects through
indirect food chain exposure.
Persistent. Highly Toxic to Humans. Bioaccumulative, and Volatile. This
combination further narrows the above chemicals to those with potential to
cause indirect pathway risks through air releases.
A fourth screen applied persistent, ecotoxic, and bioaccumulative criteria to the combined list of
constituents. This combination of screening criteria is intended to identify chemicals for which
potential harm to ecological receptors is a potential concern.
The individual criteria used in combination are described in Section 4.3. The persistence
screen consisted of a determination of whether the chemicals had soil or water column degradation rate
constants of less than 0.5/year. "Highly toxic" indicates any chemical having a CSF or Unit Risk
above the 50th percentile of all chemicals, or a chronic RfD below the 50th percentile.; Volatility was
screened against Henry's Law constant of 10"5 atm-m3/mole, and bioaccumulation potential determined
by an aquatic BCF or BAF value of greater than 1,000 L/Kg.
The-results of the combined screening of known and possible non-hazardous industrial waste
constituents are summarized in Exhibit 4-15. To a substantial degree, these results parallel the
screening-level modeling results for the TC analytes discussed in Section 3.5. Four of the nine
persistent and highly toxic chemicals are chlorinated pesticides or degradation products, along with
three metals (antimony, beryllium, and molybdenum), benzo(a)pyrene, and 2,3,7,8-TCDD. The
appearance of benzo(a)pyrene suggests that other high molecular weight PAHs (some of which are
also carcinogens) might also pass this screen if CSF values were available for these compounds. In
addition, several other chlorinated pesticides have properties that just miss the toxicity or persistence
cutoff values.
When bioaccumulation potential is added to the screening conditions (second column of
Exhibit 4-15), no chemicals drop out. This finding shows the high correlation between persistence and
bioaccumulative potential: if a chemical was not persistent, it would lack the opportunity to
accumulate in environmental media or tissue.
Page 4-33
-------
Exhibit 4-15
Multiple Screening Criteria Applied to Known
and Possible Non-Hazardous Industrial Waste Constituents
Persistent and Highly Toxic
2,3,7,8-Tetrachlorodibenzo-p-dioxin
(TCDD)
Aldrina
Antimony
Benzo[a]pyrene
Beryllium
DDE
DDT3
Dieldrin
Molybdenum
Persistent, Highly
Toxic, and
Bioaccumulative
2,3,7,8-TCDD
Aldrin3
Antimony
Benzo[a]pyrene
Beryllium
DDE
DDT3
Dieldrin
Molybdenum
Volatile,
Persistent, Highly
Toxic, and
Bioaccumulative
Aldrin3
DDE
DDT3
Persistent,
Ecotoxic, and
Bioaccumulative
2,3,7,8-TCDD
DDT3
Dieldrin
Notes:
a Use has been cancelled under FIFRA.
When the criterion of volatility is added to the preceding screens, three chemicals, all
persistent pesticides remain. This result again parallels the results seen for the TC analytes in Section
3.5. If vapor pressure cutoff (1 mm Hg), rather than Henry's Law constant (10"5 atm.-M3/mole) is
used to characterize the potential to volatilize, none of the chemicals qualify in this category.
The last column of Exhibit 4-15 identifies persistent, bioaccumulative, and ecotoxic chemicals.
As might be expected from the previous screening results, these chemicals include chlorinated
pesticides and 2,3,7,8-TCDD. Because the AWQC screen is based only on harmful concentrations, it
does not include any screening for the concentrations normally encountered in the environment. Thus,
if a much less toxic chemical (for example zinc or copper) were released into the environment in much
larger amounts than the pesticides, the exposure concentrations might be much greater and adverse
effects on ecological receptors might occur.
45 Driving Risk Pathways for the Known and Possible Non-Hazardous Industrial Waste
Constituents
EPA has previously evaluated the potential risks associated with the management of many
known and possible non-hazardous industrial waste constituents in the context of deriving proposed
risk-based exit levels for the proposed HWER-Waste rulemaking. As discussed in Section 3.5, these
proposed exit levels were derived by back-calculating concentrations in wastewaters and
nonwastewaters corresponding to acceptable risk levels. The magnitude of the modeled exit levels is
inversely proportional to the magnitude of risk posed by the chemical when placed in the specified
management units. Proposed exit levels are calculated for groundwater exposures and other pathways.
Page 4-34
-------
Thus, the proposed exit levels also indicate the relative importance of the exposure pathways for each
chemical.
Exhibit 4-16 tabulates the exit levels for 128 of the known or possible non-hazardous
industrial waste constituents (i.e., the entire combined list prior to any screens that were also addressed
in the HWIR-waste proposed rulemaking), and the exposure pathways that were risk drivers for setting
the exit levels. As in the case of the similar analysis for the TC analytes in Section 3.5, many of the
known or possible non-hazardous industrial waste constituents have proposed exit levels that are quite
low (68 are below 0.1 mg/1). Therefore, the Agency has determined that the presence of these
constituents in wastes at even relatively low concentrations may pose significant risks to human health.
Again it should be noted that the target cancer risk level used to derive the exit levels was 10~6, rather
than the 10"5 level used in the derivation of TC regulatory levels. Even so, these levels indicate
potential cause for concern for many of these chemicals at even low concentrations in wastes.
As was also the case for the TC analytes, non-groundwater pathway risks drive the
establishment of exit levels for about one-quarter of the known or possible non-hazardous industrial
waste constituents. The driving pathways include direct inhalation and vegetable and milk ingestion.
Pesticides make up a large proportion of the chemicals for which non-groundwater pathways drive the
risks, but many volatile chlorinated and nonchlorinated organics also fall into this category.
Ecological, rather than human health risks, drive the setting of proposed exit levels for two chemicals
(copper and parathion). These findings confirm the indications from the toxicity and fate and transport
screening presented in the previous sections that inhalation and indirect pathways could be of concern
for many of the known or possible non-hazardous industrial waste constituents.
4.6 Potential Acute Hazards Associated With Known and Possible Non-Hazardous Industrial
Waste Constituents
To this point, the evaluation of the potential hazards associated with the possible and known
non-hazardous industrial waste constituents has focused on chronic toxic effects. As discussed in
Chapter 3, waste constituents may also pose risks from acute exposures, as well as from physical
hazards associated with reactivity, flammability, or corrosivity. To investigate the possibility of acute
adverse effects, the Agency has compared list of the known and possible waste constituents to lists
developed by the EPA and other regulatory agencies that identify such hazardous properties. The
results of this comparison are summarized in Exhibit 4-17.
As shown in the exhibit, 38 of the known and possible non-hazardous industrial waste
constituents have been identified in one or more regulatory contexts as being acutely toxic.
Although most of these chemicals are volatile organics, several acid gases and other inorganic
compounds also are included. Appearance on these lists does not automatically indicate that acute
15 The Agency is currently revising the proposed HWIR-Waste exit level risk modeling methods in response
to comments from the Science Advisory Board and other reviewers. Thus, the proposed exit levels shown in
Exhibit 4-15 should be regarded as preliminary.
16 Edelstein, Maravene, "Memorandum to Paul Tobin on the Subject of a Database of Chemicals of Interest
for Short Term Inhalation Exposure," September 1993. Sources of data for the database include the Emergency
Planning and Community Right-to-Know Act (EPCRA) (40 CFR Part 355), Section 112(r) of the Clean Air Act
(CAA) (40 CFR Part 68), and the Occupational Safety and Health Administration (OSHA) Process Safety
Management (PSM) Standard (29 CFR Part 1910).
Page 4-35
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Exhibit 4-16
Lowest Proposed HWIR-Waste Exit Levels for
Known and Possible Non-Hazardous Industrial Waste Constituents
Constituent
1,1,1 ,2-Tetrachloroethane
1 ,1 ,1 -Trichloroethane
1 ,1 ,2,2-Tetrachloroethane
1 ,1 ,2-Trichloroethane
1 ,2,3-Trichloropropane
1 ,2.4,5-Tetrachlorobenzene
1 ,2,4-Trichlorobenzene
1 ,2-Dibromo-3-chloropropane
1 ,2-Dichlorobenzene
1 ,2-Dichloropropane
1 ,3,5-Trinitrobenzene
1 ,3-Dich!oropropyIene (1 ,3-Dichloropropene)
1 ,3-Phenylenediamine
1,4-Dioxane
2,3,4,6-Tetrachlorophenol
2,3.7,8-TCDD
2,4,5-T acid
2,4-Dichlorophenol
2,4-Dimethylphenol
2,4-Dinitrophenol
2,6-DinitrotoIuene
2-Chlorophenol
2-Ethoxyethanol
2-Nitropropane
3,3'-Dimethoxybenzidine
3-Methylcholanthrene
7,12-Dimethylbenz[a]anthracene
Acenaphthene
Acetone
Acetonitrile
Acetophenone
Acrolein
Acrylamide
Acrylonitrile
Aldrin
Allyl chloride
alpha-Hexachlorocyclohexane
Aniline
Antimony
Benz[a]anthracene
Benzidine
Benzo(a)pyrene
Benzo[b]fluoranthene
Benzyl alcohol
Benzyl chloride
Beryllium
Lowest Exit Level for
chemicals from HWIR
waste models (mg/L)
0.0078
0.0539
0.0037
0.0018
0.34
0.0317
0.685
0.000114
6.1
0.0023
0.003
0.00085
0.3
0.0136
0.58
1.78E-10
0.64
0.18
1.19
0.105
0.064
0.32
14.7
0.00019
0.0102
1.41E-06
2.76E-06
4.9
6
0.3
6.4
0.00248
0.000038
0.00034
5.64E-07
0.0742
0.000142
0.017
0.053
4.30E-06
6.80E-07
7.04E-06
0.0000661
15
1.13
0.00032
Model
Groundwater
Groundwater
Direct inhalation
Groundwater
Groundwater
Groundwater
Direct inhalation
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Direct inhalation
Direct inhalation-worker
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Direct inhalation-worker
Groundwater
Groundwater
Beef/milk ingestion
Direct inhalation
Vegetable/root ingestion
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Vegetable/root ingestion
Groundwater
Page 4-36
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Exhibit 4-16 (continued)
Lowest Proposed HWIR-Waste Exit Levels for
Known and Possible Non-Hazardous Industrial Waste Constituents
Constituent
beta-BHC
Bis(2-chloroethyl) ether
Bis(2-chloroisopropyl) ether
Bromoform
Bromomethane (Methyl bromide)
Butyl benzyl phthalate
Carbon disulfide
Chlorobenzilate
Chlorodibromomethane
Chloromethane (Methyl chloride)
Chloroprene (Chloro-1,3-butadiene, 2-)
cis-1 ,2-Dichloroethylene
cis-1 ,3-Dichloropropene
Copper
ODD
DDE
DDT
Di(2-ethylhexyl) phthalate (BEHP)
Diallate
Dibenz[a,h]anthracene
Dibutyl Phthalate (Di-n-butyl phthalate)
Dichloroditluoromethane
Dieldrin
Diethyl Phthalate
Diethylstilbestrol
Dimethoate
Dimethyl Phthalate
Diphenylamine
Disulfoton
Endosulfan
Epichlorohydrin
Ethyl acetate
Ethyl methacrylate
Ethylbenzene
Ruoranthene
Fluorene
Formaldehyde
Formic acid
Glycidylaldehyde
Hexachlorocyclopentadiene
Hexachlorophene
Indenod ,2,3-cd)pyrene
Isobutyl alcohol
Isophorone
Kepone
Lowest Exit Level for
chemicals from HWIR
waste models (mg/L)
0.00021
0.00036
0.0019
0.018
0.37
64
0.738
0.0057
0.0018
0.0959
0.515
0.64
0.00485
5.91
0.000126
9.11E-06
0.0000181
0.00044
0.26
6.34E-07
25.2
11.9
0.000059
54
2.47E-11
0.77
3
2.6
0.0131
0.94
0.335
114
6.6
8.1
1.74
3.4
0.0158
105
6.2
0.00521
5.15E-06
0.0000241
15
0.162
0.0000264
Model
Groundwater
Groundwater
Groundwater
Groundwater
Direct inhalation
Groundwater
Direct inhalation
Groundwater
Groundwater
Direct inhalation
Direct inhalation
Groundwater
Direct inhalation
Ecological (aquatic plants)
Beef/milk ingestion
Beef/milk ingestion
Beef/milk ingestion
Beef/milk ingestion
Vegetable/root ingestion
Groundwater
Groundwater
Groundwater
Beef/milk ingestion
Groundwater
Beef/milk ingestion
Groundwater
Multimedia model
Groundwater
Groundwater
Groundwater
Direct inhalation-worker
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Direct inhalation-worker
Groundwater
Groundwater
Direct inhalation
Beef/milk ingestion
Groundwater
Groundwater
Groundwater
Beef/milk ingestion
Page 4-37
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Exhibit 4-16 (continued)
Lowest Proposed HWIR-Waste Exit Levels for
Known and Possible Non-Hazardous Industrial Waste Constituents
Constituent
m-Dinitrobenzene (1 ,3-Dinitrobenzene)
Methanol
Methyl isobutyl ketone
Methyl methacrylate
Methyl parathion
Methylene bromide
Molybdenum
n-Dioctyl phthalate
N-Nitroso-dimethyl amine
N-Nitrosodi-n-butylamine
N-Nitrosodi-n-propylamine
N-Nitrosodiethylamine
N-Nitrosodiphenyl amine
N-Nitrosomethylethylamine
N-Nitrosopyrrolidine
Naphthalene
Nickel
p-Chloroaniline
Parathion
Pentachlorobenzene
Phenol
Phenylmercuric acetate
Phorate
Polychlorinated biphenyls
Pyrene
Safrole
Strychnine
Styrene
Thallium
Toluene
trans-1 ,2-Dichloroethylene
trans-1 ,3-Dichloropropene
Trichlorofluoromethane
Tris(2,3-dibromopropyl) phosphate
Vanadium (fume or dust)
Xylenes
Zinc
Lowest Exit Level for
chemicals from HWIR
waste models (mg/L)
0.0064
30
3
8.1
0.662
0.19
1.83
0.002
3.40E-06
0.000036
0.000017
3.18E-06
0.046
6.80E-06
0.000068
2.7
4.89
0.16
0.128
0.0543
32
0.0045
0.106
4.81 E-06
1.69
0.00095
0.0041
15.4
0.0192
12.6
1.12
0.0049
16
0.000099
3.71
22.4
38.4
Model
Groundwater
Groundwater
Groundwater
Groundwater
Vegetable/root ingestion
Groundwater
Groundwater
Beef/milk ingestion
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Groundwater
Ecological (fish/aquatic organisms)
Groundwater
Groundwater
Groundwater
Vegetable/root ingestion
Groundwater
Groundwater
Groundwater
Vegetable/root ingestion
Groundwater
Groundwater
Groundwater
Groundwater
Direct inhalation
Groundwater
Groundwater
Groundwater
Direct inhalation
Groundwater
Notes:
Bolded chemicals have the lowest exit level in a non-groundwater pathway
Page 4-38
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Exhibit 4-17
Potential Acute Hazards Associated with Known
and Possible Non-Hazardous Industrial Waste Constituents
Acutely Toxic Chemicals
Highly Flammable
Chemicals
Highly Reactive
Chemicals
1,1,1 -Trichloroethane
1,3-Butadiene
Acetaldehyde
Acrolein
Acrylonitrile
Allyl alcohol
Allyl chloride
Ammonia
Arsine
Bis(chloromethyl) ether
Bromomethane
Carbon disulfide
Chlorine
Chlorine dioxide
Chloromethane
Epichlorohydrin
Ethylene oxide
Fluorine
Formaldehyde
Furan
Hydrazine
Hydrogen cyanide
Hydrogen fluoride
Hydrogen sulfide
Methacrylonitrile
Methanol
Methyl iodide
Methyl isocyanate
Methyl mercaptan
Nickel carbonyl
Nitric oxide
Nitrogen dioxide
Phosgene
Phosphine
Propylene oxide
Toluene
Vinyl acetate
Xylene (mixed isomers)
1,3-Butadiene
Acetaldehyde
Chloroethane
Chloromethane
Dimethylamine
Ethane, l,l'-oxybis-
Ethylene oxide
Formaldehyde
Furan
Hydrogen cyanide
Hydrogen sulfide
Methyl mercaptan
Phosphine
Propylene oxide
Vinylidene chloride
1,3,5-Trinitrobenzene
2,4,6-Trinitrotoluene
Notes:
a See text for categorization criteria.
adverse effects will occur, only that such effects could potentially be associated with management of
wastes containing these chemicals.
Fifteen of the waste constituents are also identified as being highly flammable.17 These are
mostly volatile -organics, along with a few inorganic gases and liquids. They substantially overlap
with the previous list. Only two of the known or possible non-hazardous industrial waste constituents
are identified as being highly reactive.
17 ICF Incorporated, Draft Physical/Chemical Properties Criteria Database. October 1987. Sources of data
for the database include the Department of Transportation (DOT) Hazardous Materials Table (49 CFR 172.101)
and the National Fire Protection Association (NFPA) publication 325M, Fire Hazard Properties of Flammable
Liquids. Gases, and Volatile Solids.
Page 4-39
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4.7 Identify Individual Chemicals and Classes of Chemicals Constituting Potential Gaps
The analyses in the previous sections help to clarify the nature of potential gaps in the
hazardous waste characteristics associated with specific chemicals and chemical classes related to
chronic human health risks and ecological risks. The analyses identified groups of chemicals most
likely to be present in non-hazardous industrial waste, and screened them in terms of their toxicity,
fate, and transport properties. The results of the proposed HWIR-waste modeling were reviewed,
where available, to confirm and expand the findings of the screening results. Finally, the known and
possible non-hazardous industrial waste constituents were reviewed with regard to their potential to
cause acute adverse effects. As a result of these efforts, a number of potential gaps have been
identified, as summarized in Exhibit 4-18.
This listing of potential gaps for non-TC analytes should not be taken as being either
exhaustive or definitive. These gaps are potential, not actual gaps. They have been identified for
purposes of targeting further analysis, not for purposes of choosing what constituent or wastes to
regulate. Other potential gaps related to natural resource damages and regional or global
environmental problems are discussed in Chapter 5. Also, Chapter 6 describes how several states have
expanded the TC, implicitly identifying gaps in the TC. In Chapter 10, some of the unresolved issues
identified in Exhibit 4-18 are discussed and the available information about the potential significance
of these impacts is reviewed in detail.
EPA recognizes the limitations of this analysis. As noted previously, the data concerning the
composition of non-hazardous industrial wastes are quite limited and generally quite old. This lack of
data in large part explains the need for the elaborate screening procedures employed in this chapter.
Few data are available on the current patterns of non-hazardous industrial waste generation,
management, and disposal. In addition, the chemical-specific screening is further complicated by the
lack of toxicity and fate and transport parameter data for a large proportion of the universe of possible
waste constituents, which necessitated extensive use of professional judgment to supplement the
screening process.
Page 4-40
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Exhibit 4-18
Potential Gaps in the Hazardous Waste Characteristics Identified Based
on the Hazardous Properties of Known and Possible Non-Hazardous
Industrial Waste Constituents
Potential Gap
Basis for Identification
Important Unresolved Issues,
Data Gaps
Groundwater exposure to
toxic metals
Potential variability in groundwater
transport; finding of metals in
groundwater above HBLs in release
descriptions; proposed HWIR-waste risk
results
Amounts and concentrations
disposed; management practices;
leaching characteristics
Groundwater and inhalation
pathway exposures to volatile
chlorinated organic
compounds
Findings above HBLs in release
descriptions; large number of volatiles
among non-hazardous industrial waste
constituents; screening-level risk results;
proposed HWIR-waste risk results
Amounts and concentrations
disposed; management practices
Inhalation pathway exposure
to persistent organic pesticides
Screening level risk modeling; screening
based on toxicity, fate and transport
parameters
Whether these pesticides are still
being managed in substantial
amounts as non-hazardous
wastes
Exposure to persistent organic
pesticides and some metals
through aquatic indirect
pathways
Screening risk results; screening of waste
constituents for persistence,
bioaccumulation, toxicity, proposed
HWIR-Waste risk results indicating non-
groundwater pathways drive risks
Whether these pesticides are still
being managed in substantial
amounts as non-hazardous
wastes
Risks to aquatic ecosystems
from persistent pesticides
Ecotoxicity, persistence, bioaccumulation
screening; analogy to screening risk
modeling
Whether these pesticides are still
being managed in substantial
amounts as non-hazardous
wastes
Risks to humans, ecological
receptors from chlorinated
dioxins, PCBs
Toxicity, fate and transport screening;
analogy to screening risk results;
proposed HWIR-Waste risk results
Amounts and concentrations
managed (not high-volume
chemicals)
Endocrine disruption (humans.
and ecological receptors) from
exposure to chlorinated
pesticides, phthalate esters
Findings in release descriptions;
lexicological properties; fate and
transport screening
Dose-responses relationships for
individual and multiple agents;
combined exposures are largely
unknown
Adverse effects to humans
from exposure to "BTEX"
hydrocarbons'1
Occurrence in release descriptions above
HBLs; fate and transport screening
Amounts and concentrations
disposed
Groundwater exposures to
phenolic compounds
Occurrence in release descriptions above
HBLs
Relatively low toxicity
compounds; amounts and
concentrations in non-hazardous
wastes
Page 4-41
-------
Exhibit 4-18 (continued)
Potential Gaps in the Hazardous Waste Characteristics Identified Based
on the Hazardous Properties of Known and Possible Non-Hazardous
Industrial Waste Constituents
Potential Gap
Potential for LNAPL and
DNAPL formation, primarily
for halogenated solvents
Exposure to PAHs
Acute effects; toxicity and
other injuries
Basis for Identification
Large number of waste constituents have
physical properties consistent with
NAPL formation (mostly DNAPLs)
Occurrence in Subtitle D data;
persistence; toxicity screening
Many constituents are acutely toxic,
highly flammable, or highly reactive
Important Unresolved Issues,
Data Gaps
NAPL formation is highly
dependent on waste
characteristics and specific
management practices; few data
are available
Amounts and concentrations
disposed
Acute risks are highly dependent
upon nature and composition of
wastes and management
practices
Notes:
a Toluene, ethylbenzene, xylenes; these compounds are all commonly found in gasoline, kerosene, and
related petroleum products.
Page 4-42
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CHAPTER 5. POTENTIAL GAPS ASSOCIATED WITH
NATURAL RESOURCE DAMAGES AND LARGE-SCALE
ENVIRONMENTAL PROBLEMS
This chapter discusses risks associated with non-hazardous industrial waste management that
are not addressed in Chapters 3 or 4. Chapter 3 examined potential gaps inherent in the current
hazardous waste characteristics, thereby focusing on the adverse effects that the characteristics were
meant to address, namely risks arising primarily from acute events such as fires, explosions, and acute
exposures of waste management and transportation workers, and health risks caused by local
environmental contamination near waste management units. Chapter 4 examined potential gaps
associated with adverse human health or localized ecological effects from constituents not included in
the toxicity characteristic. This chapter addresses a third set of risks associated with non-hazardous
industrial waste management.
Section 5.1 addresses the pollution of groundwater by constituents that
diminish the value and usability of the resource without threatening human
health;
Section 5.2 addresses damage from non-hazardous industrial waste
management to air quality through odors that harm the quality of life but may
not have severe health effects; and
Section 5.3 examines possible contributions to regional and global
environmental problems from the management of non-hazardous industrial
waste, including: air deposition to the Great Waters, damages from airborne
particulates, global climate change, potential damage from endocrine
disrupters, red tides, stratospheric ozone depletion, tropospheric ozone and
photochemical air pollution, and water pollution.
These environmental problems may or may not meet the RCRA statutory or regulatory definitions of
the types of risks that the hazardous waste management program is meant to address.
5.1 Damage to Groundwater Resources
As noted in Chapter 2, the most common and well-documented impact of releases from non-
hazardous industrial waste management is groundwater contamination. If contamination is present at
high enough concentrations, the use of the groundwater as a water supply for human consumption or
other use may result in adverse effects on health. Human health risks associated with exposure to
toxic pollutants are not the only concern associated with groundwater contamination, hpwever. Non-
toxic pollutants such as iron, chloride, or total dissolved solids may be present in concentrations that
damage the aesthetic qualities and usability of the water without posing outright health hazards. In
areas where groundwater is used as a drinking water supply, such water pollution must be remediated,
limitations must be placed on its use, and/or alternative sources must be found. These actions may be
expensive and strain existing water supplies. Where alternative supplies are not economically
available, groundwater resources of marginal quality, which do not exceed health-based levels, may
continue to be used. Even where the polluted groundwater is not used for drinking water, the value of
Page 5-1
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the resource may decline because it is no longer available for future use as drinking water without
remediation.
This non-toxic pollution of groundwater from non-hazardous industrial waste management was
found relatively often in the environmental release descriptions summarized in Chapter 2. Seventy-
five (84 percent) of the 89 release descriptions with data on regulatory levels had constituents detected
at levels exceeding non-health-based or non-ecologically-based standards, principally on aesthetic or
usability criteria developed under the Safe Drinking Water Act as Secondary Maximum Contaminant
Levels (SMCLs). Releases at 70 of these 75 sites also exceeded health and/or ecological-based
standards. Of the 177 non-TC constituents identified in the release case studies, 9 constituents (plus
pH and total dissolved solids) have SMCLs. (Some of these constituents also have health-based or
ecologically-based levels.) Exhibit 5-1 lists all constituents with SMCLs and shows how frequently
they were found among the 89 case studies where concentration and regulatory standards data were
available. The most commonly detected constituents, iron, chloride, and manganese, all have SMCLs.
Also, all SMCLs, except those for foaming agents, color, and corrosivity, were violated by at least
several documented releases. (See Exhibit 2-6 for additional data on the concentrations at which these
constituents were detected.)
Exhibit 5-1
Constituents/Properties with SMCLs Found in Release Descriptions
Constituents/Properties
PH
Iron
Chloride
Sulfate
Total dissolved solids
Manganese
Zinc
Copper
Aluminum
Fluorides
Color
Corrosivity
Odor
Foaming agents
Number of Times Detected
66
54
52
50
48
39
33
17
12
12
0
0
0
0
Number of Times Detected
Above SMCL
24
49
32
29
29
34
13
2
12
4
0
0
0
0
5.2 Damage to Local Air Quality from Odors
Noxious odors historically have been reported in the vicinity of waste management facilities.
Odor problems have caused minor health problems, reduced the quality of life, and reduced property
values near such facilities. Information on the extent of such problems from non-hazardous industrial
waste management is very limited. Odor problems were reported in several of the release descriptions
initially identified by EPA, but these cases were excluded because they did not meet the Agency's
strict selection criteria. Only one release description included reports by residents of odor problems.
Page 5-2
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Nevertheless, the case study development methodology may have missed many cases of odor problems
from non-hazardous industrial waste management facilities because state regulatory programs largely
focus on groundwater concerns. Also, odor problems are often handled at the local level and thus the
states may not get involved.
The potential for odor problems clearly exists at non-hazardous industrial waste facilities that
manage certain types of wastes. For example, food processing facilities (e.g., slaughterhouses that
must dispose of offal and alimentary contents from slaughtered animals) may have odor problems if
their air releases are not carefully managed. In addition to food wastes, potential odor problems may
arise from chemical wastes. Exhibit 5-2 lists a number of the chemicals identified in the release
descriptions (although not necessarily for odor) that have extremely low odor thresholds in either air or
water. Ten of these chemicals have threshold odor concentrations in air (the lowest concentrations at
which odors can be detected or recognized) of 0.01 mg/m3 or less, and six of them can be detected by
odor in water solutions at concentrations of 0.006 mg/1 or less.
Exhibit 5-2
Chemicals from Release Descriptions with Low Odor Thresholds
Chemical Name
Threshold Odor
Concentrations in Ah*
(mg/m3)
Threshold Odor
Concentrations in Water
(mg/1)
1,2,4-Trichlorobenzene
2,4,6-Trichlorophenol
2,4-Dimethylphenol
Acetophenone
Benzenethiol
beta-BHC
Chlordane
Cresol (mixed isomers)
Diphenyl ether
Hexachloro-l,3-butadiene
Hexachlorocyclopentadiene
Hexachloroethane
Methyl mercaptan
Nitrobenzene
o-Cresol
p-Cresol -
0.005
0.001
0.001
0.01
0.0005
0.001
0.01
0.0002
0.01
0.0003
0.004
0.0003
0.0000025
0.006
0.0016
0.001
Source: Verscheuren, Karel, Handbook of Environmental Data on Organic Chemicals. Second Edition,
1983
Because odor problems typically are handled locally and these problems likely do not meet the
RCRA definition of risks meant to be addressed by the hazardous waste management program, EPA
does not plan to investigate this area further following the Scoping Study.
Page 5-3
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5.3 Large-Scale Environmental Problems
EPA considered whether any major large-scale environmental problems (e.g., global climate
change, potential damage from endocrine disrupters) might be caused, at least to some extent, by non-
hazardous industrial wastes. Depending on the types of wastes and on the relative contributions of
these wastes to the problem areas, changes in the hazardous waste characteristics might be one method
to help reduce further damages.
Exhibit 5-3. Initial List of
Large-Scale Environmental Problems
Air deposition to the Great Waters
Damages from airborne participates
Global climate change
Potential damages from endocrine disrupters
Red tides
Stratospheric ozone depletion
Tropospheric ozone and photochemical air
pollution
Water pollution
EPA began this phase of the Scoping
Study by developing an initial list of major
large-scale environmental problems (or possible
problems) that have potential links to non-
hazardous industrial wastes (see Exhibit 5-3).
Several of these problems overlap considerably
with each other and with exposure and other
damage pathways discussed previously.
Furthermore, EPA recognizes that other
environmental problems have potential links to
non-hazardous industrial waste; however, given
the limited resources available for this Scoping
Study, the Agency chose to limit this analysis to
some of the more likely areas of concern.
Following the development of this list, EPA conducted preliminary evaluations of the problem
areas to try to characterize the contributions to the problems from non-hazardous industrial wastes.
Because these problems are typically characterized by highly complex interactions of a large number
of factors, determining the exact contribution of non-hazardous industrial wastes to each problem is
difficult and beyond the scope of this study. Instead, EPA was able to conduct only initial evaluations
to identify areas that may have a significant contribution from non-hazardous industrial wastes and
thus may warrant further analysis following the Scoping Study.
For environmental problems with a possible link to non-hazardous industrial wastes, EPA
identified (where possible) the industries and waste streams that could be contributing to the problems
and the relevant statutes and programs that are addressing the areas. The environmental problems
evaluated for this Scoping Study are discussed below in the order (alphabetical) listed in Exhibit 5-3.
5.3.1 Air Deposition to the Great Waters
Pollutants emitted into the atmosphere are transported various distances and can be deposited
to aquatic ecosystems -far removed from their original sources.1 Studies show that significant
portionsoften greater than 50 percentof pollutant loadings to the Great Waters (i.e., Great Lakes,
Lake Champlain, Chesapeake Bay, and coastal waters) are from atmospheric deposition. Thus, this
pathway is an important factor in the degradation of water quality and the associated adverse health
and ecological effects. Because of the mounting concern that air pollution contributes to water
pollution, Congress included Section 112(m), Atmospheric Deposition to Great Lakes and Coastal
Waters, in the Clean Air Act Amendments of 1990.
1 U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Deposition of Air
Pollutants to the Great Waters, First Report to Congress, EPA-453/R-93-055, May 1994.
Page 5-4
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Both local and distant air emission sources contribute to a pollutant load at a given location.
The sources of concern for the Great Waters primarily include industrial activities and processes
involving combustion. At present, however, a complete and comprehensive inventory of the locations
of particular sources and the amount of individual toxic pollutants that each source emits to the air is
lacking. Nevertheless, EPA has identified several known air pollutants of concern for Great Waters.
Exhibit 5-4 lists these pollutants and selected U.S. sources. Most pollutants in this exhibit are TC
analytes, while a smaller set are chemicals (or chemical groups) of concern discussed in Chapter 4.
Thus, these pollutants are likely candidates for further analysis as potential gaps in the hazardous
waste characteristics.
Exhibit 5-4. U.S. Sources of Air Pollutants of Concern for Great Waters3
Pollutant
Cadmium and
compounds
Chlordane
DDT/DDE
Dieldrin
Hexachloro-
benzene
cc-HCH
Lindane
Lead and
compounds
Mercury and
compounds
PCBs
Polycyclic
organic
matter
Sources of Air Emissions
Fossil fuel combustion; aluminum production; cadmium, copper, lead, and zinc smelting; iron and steel
production; battery manufacturing; hazardous waste and sewage sludge incineration; municipal waste
combustion; petroleum refining; lime manufacturing; cement manufacturing; pulp and paper production;
combustion of waste oil; pigment manufacturing; soil-derived dust; volcanoes
Insecticide application;15 volatilization from soils, water, and treated building foundations due to past insecticide
application; suspension of eroded soil particles
Insecticide application;15 volatilization from soils and water due to past insecticide application
Insecticide application;19 volatilization from soils and water due to past insecticide application
Manufacturing of chlorine and related compounds; combustion of materials containing chlorine; pesticide
manufacturing; municipal waste combustion; fungicide application;11 volatilization from soils and water due to
past fungicide application
Insecticide application;6 volatilization from soils and water due to past insecticide application
Insecticide application;15 volatilization from soils and water due to past insecticide application
Fossil fuel combustion; aluminum production; lead smelting; ferroalloys production; iron and steel production; ,
battery manufacturing; hazardous waste and sewage sludge incineration; municipal waste combustion; petroleum
refining; lime manufacturing; cement manufacturing; asphalt and concrete manufacturing; pulp and paper
production; combustion of waste oil; paint application;1* motor vehicles;1* forest fires; suspension of eroded soil
particles; volcanoes
Fossil fuel combustion; copper and lead smelting; hazardous waste; municipal waste, medical waste, and sewage
sludge incineration; lime manufacturing; cement manufacturing; chlorine and caustic soda manufacturing; paint
application;1" suspension of eroded soil particles; erosion from soils and water; volcanoes
Incineration and improper disposal of PCB-contaminated waste; disposal of waste oil; malfunction of PCB-
containing transformers and capacitors; electrical equipment manufacturing; pulp and paper production;
volatilization from soils and water; municipal solid waste incineration and unregulated combustion
Combustion of plant and animal biomass and fossil fuels; municipal waste combustion; petroleum refining; steel
production; coke by-product recovery; aluminum production; plywood and particle board manufacturing; surface
coating of auto and light duty trucks; asphalt processing; dry cleaning (petroleum solvent); fabric printing,
coating, and dyeing; forest fires
Page 5-5
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Exhibit 5-4. U.S. Sources of Air Pollutants of Concern for Great Waters2
(continued)
Pollutant
2,3,7,8-TCDF
2,3,7,8-
TCDD
Toxaphene
Nitrogen
compounds
Sources of Air Emissions
Hazardous, industrial, municipal, and medical waste and sewage sludge incineration; combustion of fossil fuels
and organic materials containing chlorine; by-product of various metals recovery processes, such as copper
smelting; accidental fires of treated wood products and PCB-containing transformers and capacitors; improper
disposal of certain chlorinated wastes; pesticide production, application, and spills; pulp and paper production;
volatilization and erosion of dust from landfill sites; forest fires
Hazardous, industrial, and medical waste and sewage sludge incineration; municipal waste combustion;
combustion of fossil fuels and organic materials containing chlorine; by-product of various metals recovery
processes, such as copper smelting; accidental fires of treated wood products and PCB-containing transformers
and capacitors; improper disposal of certain chlorinated wastes; pesticide production, application, and spills; pulp
and paper production; volatilization and erosion of dust from landfill sites; forest fires
Insecticide application;11 volatilization from soils and water due to past insecticide application
Fossil fuel and other types of combustion; motor vehicles; fertilizer application; animal waste
* From Table 9 of U.S. EPA, Deposition of Air Pollutants to the Great Waters, supra footnote 1.
b Not currently a significant source in the U.S. due to manufacturing or use restrictions.
5.3.2 Airborne Particulates
Airborne paniculate matter (PM) is one of the six high-priority research topics identified for
the next few years by the EPA Office of Research and Development (ORD).2 PM includes dust, dirt,
soot, smoke, and liquid droplets directly emitted into the air by sources such as factories, power plants,
transportation sources, construction activity, fires, and windblown dust. Concern regarding PM from
non-hazardous industrial waste includes toxic constituents entrained on particulates. PM is also
formed in the atmosphere by condensation or transformation of emitted gases such as sulfur dioxide,
nitrogen oxides, and volatile organic compounds into small droplets.
Based on studies of human populations exposed to high concentrations of particles (often in
the presence of sulfur dioxide) and on laboratory studies of animals and humans, the major concerns
for human health include effects on breathing and respiratory symptoms, aggravation of existing
respiratory and cardiovascular disease, alterations in the body's defense systems against foreign
materials, damage to lung tissue, carcinogenesis, and premature death. The major subgroups of the
populations that appear likely to be most sensitive to the effects of paniculate matter include
individuals with chronic obstructive pulmonary cardiovascular disease, individuals with influenza,
asthmatics, the elderly, and children. Paniculate matter may injure crops, trees and shrubs, and may
damage metal surfaces, fabrics, and other materials. Fine particulates also impair visibility by
scattering light and reducing visibility. The haze caused by fine particles can diminish crop yields by
reducing sunlight.
2 U.S. Environmental Protection Agency, Office of Research and Development, Strategic Plan for the Office of
Research and Development, ORD, EPA/600/R-96/059, May 1996.
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PM is increasingly being identified as posing a high potential for health and environmental
risk and other potential damages. Nevertheless, EPA does not believe that PM is a significant waste
characterization issue but rather a waste management issue. Furthermore, other programs (e.g., CAA
National Ambient Air Quality Standards) are designed to address this area. Therefore, airborne
particulates are not planned for further study as a potential gap.
5.3.3 Global Climate Change
Evidence is mounting that the increasing concentrations of greenhouse gases (GHGs) will
ultimately raise (and some believe are currently raising) atmospheric and ocean temperatures
significantly, which may in turn alter global weather patterns.3 Global climate already has changed
over the past century, and the balance of evidence suggests a discernible human influence.4 Climate
is expected to continue to change in the future.
EPA conducted a brief review of the major anthropogenic sources of the two predominant
GHGs, carbon dioxide (CO2) and methane (CH4), to determine the relative contributions of
non-hazardous industrial wastes, including their co-disposal with municipal solid waste (MSW).
Before describing the results of this review, it is essential to understand some of the international
conventions used to evaluate GHG emissions, as these conventions have a strong bearing on the
results.
The United States and all other parties to the Framework Convention on Climate Change
agreed to develop inventories of GHGs for purposes of developing mitigation strategies and
monitoring the progress of those strategies. The Intergovernmental Panel on Climate Change (IPCC)
developed a set of inventory methods to be used as the international standard.5 The screening
methodology used in this section to evaluate emissions and sinks of GHGs attempts to be consistent
with IPCC's guidance.
One of the elements of the IPCC guidance that deserves special mention is the approach used
to address CO2 emissions from biogenic sources. For many countries, the treatment of CO2 releases
from biogenic sources is most important when addressing releases from energy derived from biomass
(e.g., burning wood), but this element is also important when evaluating waste management emissions
(for example, the decomposition or combustion of grass clippings or paper). The carbon in paper and
grass trimmings was originally removed from the atmosphere by photosynthesis, and under natural
conditions, it would eventually cycle back to the atmosphere as CO2 due to degradation processes.
The quantity of carbon that these natural processes cycle through the earth's atmosphere, waters, soils,
and biota is much greater than the quantity added by anthropogenic GHG sources. But the focus of
the Framework Convention on Climate Change is on anthropogenic emissions - emissions resulting
from human activities and subject to human control - because these emissions have the potential to
alter the climate by disrupting the natural balances in carbon's biogeochemical cycle.
3 U.S. Environmental Protection Agency, Office of Policy, Planning, and Evaluation, Environmental Goals for
America, with Milestones for 2005 (Draft for Federal Review), June 1996.
4 Intergovernmental Panel on Climate Change (IPCC), Climate Change 1995: The Science of Climate Change,
Second Assessment Report, Cambridge University Press, 1996.
5 IPCC, WGI Technical Support Unit, IPCC Guidelines for National Greenhouse Gas Inventories: Reporting
Instructions, Bracknell, U.K., 1995.
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Thus, for processes with CO2 emissions, if the emissions are from biogenic materials and the
materials are grown on a sustainable basis, then those emissions are considered to simply close the
loop in the natural carbon cycle; that is, they return CO2 to the atmosphere that was originally
removed by photosynthesis. In such cases, the CO2 emissions are not counted (and thus most CO2
emissions from landfills are not counted). On the other hand, CO2 emissions from burning fossil fuels
ore counted because these emissions would not enter the cycle were it not for human activity.
Likewise, CH4 emissions from landfills are counted, even though the source of carbon is primarily
biogenic. CH4 would not be emitted but for the human activity of landfilling the waste, which creates
anaerobic conditions conducive to CH4 formation.6 This approach does not distinguish between the
timing of CO2 emissions, provided that they occur in a reasonably short time scale relative to the
speed of the processes that affect global climate change. That is, as long as the biogenic carbon would
eventually be released as CO2, it does not matter whether it is released virtually instantaneously (e.g.,
from combustion) or over a period of a few decades (e.g., decomposition on the forest floor).
CO2 accounts for the largest share of U.S. GHG emissions, comprising 1,408 million metric
tons of carbon equivalent (MMTCE) out of total 1994 U.S. emissions of 1,666 MMTCE.7
Combustion of fossil fuels results in the vast majority of the CO2 emissions (1,390 MMTCE), with the
remainder from industrial processes such as cement production, lime production, limestone
consumption (e.g., iron and steel production), soda ash production and use, and CO2 manufacture.
CO2 emitted from landfills as a product of both aerobic and anaerobic decomposition of organic
wastes is not counted, as described above.
Methane is the second most important GHG; U.S. emissions in 1994 were 166 MMTCE.8 Of
the anthropogenic CH4 sources, the largest is landfills (which contribute 36 percent of the total U.S.
methane emissions), agricultural activities (32 percent), coal mining (15 percent), production and
processing of natural gas and oil (11 percent), fossil fuel combustion (3 percent), and wastewater
treatment (0.6 percent).9 As explained above, CH4 from landfills is counted as an anthropogenic
GHG.
The majority of landfill CH4 emissions result from MSW landfills (90 to 95 percent), with the
remaining methane emitted from the disposal of industrial wastes. Methane emissions from large
MSW landfills, however, are currently regulated under EPA's recent New Source Performance
Standards and Emissions Guidelines, which require collection and control of landfill gas. Small
MSW landfills and industrial waste monofills are not subject to these new regulations and thus may
warrant further investigation. This is particularly true for small landfills or monofills managing non-
6 Because CH4 has a higher global wanning potential than CO2, CH4's incremental global wanning potential
is counted.
7 U.S. Environmental Protection Agency, Office of Policy Planning and Evaluation, Inventory of U.S. Greenhouse
Gas Emissions and Sinks: 1990-1994, EPA 230-R-96-006, November 1995.
8 Ibid.
9 Ibid.
10 61 Federal Register 9905, March 12, 1996.
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hazardous industrial wastes that have a high biochemical oxygen demand (such as wastes from paper
mills and food processing), which have a high potential for generating CH4.
In conclusion, non-hazardous industrial wastes may contribute to GHG emissions to the extent
that they are highly degradable and either are disposed in small landfills (which are not subject to the
landfill gas rule) or are released directly to the atmosphere. The emissions attributable to these wastes
are small compared to other sources of GHGs. Nevertheless, the same highly putrescible wastes that
would be of concern when disposed in a landfill environment are likely to cause taste and odor
problems that adversely affect local air and water quality. To a large degree, the climate change risk
(and much of the potential groundwater resource damage) could be readily averted for highly
putrescible wastes by biological pretreatment prior to land disposal to reduce the potential for (a)
methane formation and (b) production of odiferous compounds generated in an anaerobic environment.
Further research could be conducted in this area to determine whether the potential contribution of
non-hazardous industrial wastes to GHG emissions could be significant. However, given the current
coverage of this problem area by other programs besides Subtitle C of RCRA, EPA does not plan to
pursue global climate change within the context of the hazardous characteristics at this time.
5.3.4 Potential Damages from Endocrine Disrupters
Over the past decade, increased attention has been given to a class of chemicals with high
persistence, bioaccummulation potential, and toxicity. These chemicals, often referred to as PBTs,11
include a wide range of substances, generally several metals and a variety of organic compounds.
EPA's involvement in PBT research and regulation has encompassed many programs. One of these
programs, waste minimization, developed the Waste Minimization National Plan.12 This plan
established a national goal to reduce the most persistent, bioaccumulative, and toxic chemicals in
hazardous wastes by 25 percent by the year 2000 and by 50 percent by the year 2005. Currently
many international organizations, including the North American Commission for Environmental
Cooperation and various United Nations groups, are debating PBT public policy and ultimately could
generate binding commitments (e.g., treaties) that could affect U.S. national policy on PBTs. For
example, an initial list of 12 PBTs is being considered for control under an international protocol.
Recently, interest in PBTs has escalated due to the growing attention on a subgroup of these
chemicals called "endocrine disrupters" (EDs). EDs are substances that have the potential to interfere
with hormonal systems in ecological and human receptors. The results of such interference might
include adverse reproductive or developmental effects, certain kinds of cancers, learning and
11 Several other terms are and have been used, such as persistent organic pollutants, which actually are a subset
of PBTs.
12 U.S. Environmental Protection Agency, Office of Solid Waste, "The Waste Minimization National Plan,"
EPA530-R-94-045, 1994.
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behavioral problems, and immune system deficiencies.13 Recent concern has focused on the
potential synergistic effects of EDs.
14
Significant scientific debate still exists regarding which chemicals are EDs and the degree to
which EDs have caused or have the potential to cause adverse human health and environmental
effects. This debate has prompted great interest in researching the scope of ED impacts. For example,
the study of EDs is one of the six high-priority research topics identified by EPA's Office of Research
and Development (ORD) for the next few years.15 It has also been made a high priority by the U.S.
chemical industry; the Chemical Industry Institute for Toxicology (GET) has reprogrammed much of
its research budget into this area. To the extent that the impact of EDs on the environment are largely
unknown, these chemicals may represent a substantial gap in the hazardous waste regulations.
Notwithstanding the current debate, recent review articles summarize convincing evidence that
a variety of chemical pollutants can act as endocrine disrupters in wildlife populations.16 Some
specific examples include the following:
Reptiles. Researchers found that the reproductive development of alligators
from Lake Apopka, Florida was severely impaired, apparently due to DDE, a
metabolite of DDT and dicofol.17 The lake is located adjacent to an EPA
Superfund site where a dicofol spill had occurred. The specific adverse effects
included decreased testosterone and abnormal testicular cells in males and
increased estrogen and altered ovaries (increased polyovular follicles and
polynuclear oocytes) in females.
13 Center for the Study of Environmental Endocrine Effects, Environmental Endocrine Effects: An Overview
of the State of Scientific Knowledge and Uncertainties, Discussion Draft (first released for public comment at the
Sept 22, 1995 public meeting of the Science Advisory Board of the U.S.-Canada International Joint Commission),
Washington, DC (also available on the World Wide Web at http://www.endocrine.org).
14 Arnold, SF, Klotz, DM, Collins, BM, Voider, PM, Guillette Jr., LJ, and McLachlan, JA, "Synergistic
Activation of Estrogen Receptor with Combinations of Environmental Chemicals," Science, 272 (5267): 1489, June
7,1996; and Suplee, C, '"Environmental Estrogens' May Pose Greater Risk, Study Shows," The Washington Post,
p. A4, June 7, 1996.
15 Strategic Plan for the Office of Research and Development, supra footnote 2.
16 Colborn, T., vom Saal, F.S., and Soto, A.M., "Developmental Effects of Endocrine-Disrupting Chemicals in
Wildlife and Humans," Environmental Health Perspectives. 101(5):378-384, 1993; Guillette, L.J., Grain, D.A.,
Rooney, A.A., and Pickfbrd, D.B., "Organization Versus Activation: The Role of Endocrine-Disrupting Contaminants
(EDCs) During Embryonic Development in Wildlife," Environmental Health Perspectives. 103(Supp 7): 157-164,
1995.
17 Guillette, LJ., Gross, T.S., Masson, G.R., Matter, J.M., Percival, H.F., and Woodward, A.R, "Developmental
Abnormalities of the Gonad and Abnormal Sex Hormone Concentrations in Juvenile Alligators From Contaminated
and Control Lakes in Florida," Environmental Health Perspectives. 102(8):680-688, 1994.
Page 5-10
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Birds. A number of researchers have documented severely impaired
reproductive success in herring gulls from the Great Lakes. Some specific
observations include large clutch sizes (attributed to nest sharing by two
females), female-female pair bonds, embryonic and chick mortality, and altered
nest defense and incubation behavior. These effects were associated with high
levels of organochlorines (e.g., DDT, dioxins, and mirex) in the 1960s and
early 1970s. Reproductive success increased as levels of these compounds
declined in the late 1970s and 1980s. Organochlorines that have been
identified as estrogenic to bird embryos in laboratory studies include DDT and
methoxychlor.
19
In these cases, some of the causative agents appear to be organochlorine pesticides that are no
longer produced (e.g., DDT) yet persist in the environment due to the nature of their chemical/physical
properties. Although these chemicals are not generally expected to be components of non-hazardous
industrial wastes, a number of similar chemicals currently used hi industry have demonstrated similar
endocrine disrupting properties in laboratory studies. These EDs are often present in treated sewage
effluent,20 and are likely to be components of non-hazardous industrial waste.
A recent field study found that effluent from sewage treatment works induced vitellogenin
synthesis in male fish, indicating that the effluent is estrogenic.21 The effects were pronounced and
occurred at all sites tested. The identity of the chemical or chemicals in the sewage effluent causing
the effects is not known, however. A number of chemicals known to be present in sewage effluent
were tested for estrogenic effects in fish. These chemicals included nonylphenol, octylphenol,
bisphenol-A, DDT, and PCBs. Furthermore, a mixture of different estrogenic chemicals was found to
be considerably more potent than each of the chemicals when tested individually, a finding that
recently was replicated.22
In addition to the effects described above, other documented endocrine disrupting effects in
wildlife populations from industrial effluents have unknown causative agents. For example, kraft mill
effluent caused a variety of effects in two fish species: white suckers and mosquitofish. Lake
Superior white suckers collected from a site receiving primary-treated bleached kraft mill effluent
18 Fox, G.A., "Epidemiological and Pathobiological Evidence of Contaminant-Induced Alterations in Sexual
Development in Free-Living Wildlife," in Colborn, T., and Clement, C. (eds.), Chemically-Induced Alterations in
Sexual and Functional Development: The Wildlife/Human Connection. Princeton Scientific Publishing, Princeton,
NJ, pp. 147-158, 1992.
19
Fry, D.M.-, "Reproductive Effects in Birds Exposed to Pesticides and Industrial Chemicals," Environmental
Health Perspectives. 103(Supp 7):165-171, 1995.
20
Sumpter, J.P., and Jobling, S., "Vitellogenesis as a Biomarker For Estrogenic Contamination of the Aquatic
Environment," Environmental Health Perspectives. 103(Supp 7):173-178, 1995.
21 Ibid.
22 Arnold, S.F., et al., supra footnote 14.
23 Munkittirck, K.R., Portt, C.B., Van Der Krakk, G.J., Smith, I.R., and Rokosh, D.A., "Impact of Bleached Kraft
Mill Effluent on Population Characteristics, Liver MFO Activity, and Serum Steroid Levels of A Lake Superior
White Sucker (Catostomus Commersoni) Population, Can. J. Fish. Aquat. Sci.. 48:1371-1380, 1991.
Page 5-11
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exhibited increased age to maturity, smaller gonads, lower fecundity with age, and an absence of
secondary sex characteristics. Masculinization of female mosquitofish was noted downstream from the
discharge of kraft mill effluent in Elevenmile Creek in Florida.24
Several of the chemicals identified in this section are also identified in Chapter 4 as known or
possible non-hazardous industrial waste constituents. Some of the relevant chemical groups are
described in more detail below.
Alkylphenol Compounds. Alkylphenol-polyethoxylates are non-ionic
surfactants commonly used in industrial and domestic detergents as well as
some shampoos and cosmetics. Alkylphenols are used as antioxidants in some
clear plastics. Alkylphenol-polyethoxylates are biodegraded to alkylphenols
during sewage treatment. These compounds persist in rivers and their
sediments and can migrate to groundwater. These compounds also have the
ability to bioconcentrate in animals.
BisphenoI-A. This compound is used to manufacture polycarbonate, a
component in a wide array of plastics and other polymer products. Bisphenol-
A also is used to manufacture epoxy resins, which are components of a variety
of lacquers and adhesives.
Phthalates. Phthalates are one of the most abundant man-made chemicals in
the environment. Phthalate esters are used in the production of various
plastics. Butylbenzyl phthalate (BBP) also is used in the production of vinyl
floor tiles, adhesives, and synthetic leather. Di-n-butylphthalate (DBF) is a
common plasticizer in food-packaging materials and polyvinyl chloride.
Thousands of tons of plastics are disposed of annually in landfills, thus
possibly enabling phthalate esters to migrate into soil and groundwater. These
compounds have the ability to bioconcentrate in animals.
As seen in Chapter 4, other categories of chemicals with ED characteristics (e.g., heavy metals) are
present in wastes generated by numerous industries.
In conclusion, the evidence that alkylphenols, bisphenol-A, and phthalates are endocrine
disrupters is based mainly on laboratory studies. The effects of these chemicals on wildlife
populations is not known. Based on the endocrine disrupting effects of organochlorines on populations
of fish, birds, reptiles, and mammals, however, it is possible that alkylphenols, bisphenol-A, phthalates,
and other chemicals also could have endocrine disrupting effects in wildlife. Furthermore, as seen in
Chapter 4, it is'likely that some of these chemicals (e.g., the phthalates) are also components of several
non-hazardous industrial wastes.
24 Davis, W.P., and Bortone, S.A., "Effects of Kraft Mill Effluent on the Sexuality of Fishes: An Environmental
Early Warning?" in Colborn, T., and Clement, C. (Eds.), Chemically-Induced Alterations in Sexual and Functional
Development: The Wildlife/Human Connection. Princeton Scientific Publishing, Princeton, N.J., pp. 113-127,1992.
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5.3.5 Red Tides
Red tides are rapid increases in growth (i.e., blooms) of freshwater and marine plants called
dinoflagellates, which typically are microscopic unicellular organisms that photosynthesize but also
have tails for movement. A red tide occurs when dinoflagellates multiply rapidly due to optimal
growth conditions such as abundant dissolved nutrients and sunlight. They produce toxins to defend
themselves from zooplankton and other aquatic grazers. The term red tides includes orange, brown,
red, and even green blooms.
Shellfish, such as clams, mussels, oysters, or scallops, consume dinoflagellates and can
accumulate the toxins in their flesh. Usually, the shellfish are not severely affected, but they can
contain enough toxins to sicken and even kill humans. The recently discovered Pfiesteria piscida is
one of many species of dinoflagellate that causes red tides. It produces potent toxins that cause
bleeding sores in fish and can adversely affect humans via air releases. It recently has caused massive
fish kills in the Neuse and Pamlico Rivers in North Carolina.25
Several case studies have shown the relationship between the levels of nutrients, such as
phosphorus, nitrogen, silicon, and iron, in coastal and fresh waters, and the proliferation of red
tides.26 Studies also have shown that the high levels of nutrients and eutrophication of the water
(which favors the development of red tides) are often caused by surrounding human development and
industrial and domestic wastewaters.27 Recent development of agribusiness and factory farms in
coastal areas releases wastes with high levels of nutrients into the water that may favor red tides.
Some researchers believe that the occurrence of red tides has been increasing over the years,
although improvements in the monitoring and reporting of red tides could account for this.29 Even
if such an increase were occurring, however, a commensurate increase in human poisoning from
25 Broad, W.J., "A Spate of Red Tides Menaces Coastal Seas," The New York Times, August 27, 1996; and
Lewitus, A.J., R.V. Jesien, T.M. Kana, J.M. Burkholder, H.B., Jr., Glasgow, E. May, "Discovery of the Phantom
Dinoflagellate in Chesapeake Bay," Estuaries 18(2):373-378, 1995.
26 Ikeda, T., T. Matsumoto, H. Kisa, Y. Ishida, A. Kawai, "Analysis of Growth Limiting Factors Causative of
Freshwater Red Tide by Dinoflagellate Peridinum Bipes F. Occultatum," Jap.-J.-Limnol.-Rikusuizatsu. 54(3): 179-
189, 1993; Jiang, G., "The Preliminary Study on The Eutrophication and the Red Tide in the South Coastal Area
of Zhejiang, Donghai-Mar.-Sci.-Donghai-Haivang. 11(2): 55-6, 1993; Okaichi, T., S. Montani, A. Hasui, "The Role
of Iron in the Outbreaks of Chattonella Red Tide," Red Tides: Biology, Environmental Science, and Toxicology,
Proceedings of the First International Symposium on Red Tides, held in November 10-14, 1987, in Takamatsu,
Kagawa-Prefecture, Japan, p. 353-356; and "Thousands of Gulf Fish Die; Red Tide Is Probable Cause," The New
York Times, September 1996.
27 Skojoldal, H.R., "Eutrophication and Algal Growth in the North Sea," Mar. Environ. Cent.. Mar. Res.. Bergen-
Nordnes, Norway, p. 445-478, undated.
28 Wu, R.S.S., "The Environmental Impact of Marine Fish Culture: Towards a Sustainable Future," International
Conference on Marine Pollution and Ecotoxicology, held in Hong Kong, Jan. 22-26,1995, Vol. 31, no. 4-12, p. 159-
166; and Broad, supra footnote 25.
29 Personal communications with Tony Amos, University of Texas Marine Science Institute, Port Aransas, Texas,
and Daniel Baden, School of Marine and Atmospheric Science, Miami, Florida, on October 22, 1996.
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ingestion of shellfish contaminated with dinoflagellate toxins has not been seen, likely because of the
improved monitoring and reporting of red tides.
Notwithstanding the potential link between red tides and constituents that are often found in
non-hazardous industrial waste, little if any evidence has been found during this review concerning the
degree to which these wastes may be contributing to the problem. Therefore, for the purposes of this
hazardous waste characteristic gaps study, EPA does not plan to conduct further research in this area at
this time.
5.3.6 Stratospheric Ozone Depletion
The stratospheric ozone layer protects living organisms from damaging solar ultraviolet
radiation (UV-B). Depletion of the ozone layer means a greater amount of UV-B radiation is reaching
the earth's surface, which increases human skin cancers and cataracts, impairs human immune systems,
reduces crop yields, and damages plant and animal life.31 Several industrial chemicals, including
chlorofluorcarbons (CFCs), halons, carbon tetrachloride, methyl chloroform, and methyl bromide, are
known to be stratospheric ozone-depleting substances (ODSs).
For many years, ODSs have been used in a variety of manufacturing and other activities.
With the ratification of the Montreal Protocol and its subsequent amendments and adjustments, the
United States agreed to eliminate the production of ODSs by January 1, 1996 (with a few exceptions).
In addition, the disposal of ODSs is tightly controlled in order to prevent further ozone depletion.
Thus, EPA believes that, for purposes of the hazardous waste characteristic gaps analysis, ozone-
depleting and non-ozone-depleting risks (e.g., via inhalation during combustion or from groundwater
during land disposal of residuals) do not need to be examined further at this time.
In a related area (though not necessarily a large-scale environmental problem), the ultimate
elimination of ODSs has spurred the development of a large number of alternative chemicals and
technologies to replace ODSs. In the United States, the Significant New Alternatives Policy (SNAP)
Program was put in place by EPA to ensure that alternatives implemented to replace ODSs are not
themselves environmentally harmful or unsafe for workers and others who might be exposed to the
new chemicals. As part of this program, EPA has developed a series of SNAP Technical Background
Documents to address the ODS substitutes.32 Before a new alternative is developed and introduced
into interstate commerce, EPA must review the alternative and categorize it as acceptable, acceptable
with limitations, or unacceptable, based on a risk screen of the alternative's characteristics. This risk
screen addresses global atmospheric effects of the alternative, as well as worker, consumer, and
general population exposure. Thus, groundwater damage and other more local adverse effects of the
alternative from solid waste generation and management are included in this screening process.
Therefore, EPA does not intend to conduct further investigations into the solid waste and hazardous
characteristics implications of the SNAP-approved alternatives at this time.
30
Personal communication with Scott Rippey, U.S. Food and Drug Administration, October 21, 1996.
31 Environmental Goals for America, with Milestones for 2005 (Draft for Federal Review), supra footnote 3.
32 The majority of these documents were developed to support the first key substitutes rulemaking (59 Federal
Register 13044, March 18, 1994).
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5.3.7 Tropospheric Ozone and Photochemical Air Pollution
Photochemical reactions between organic chemicals, nitrogen oxides, and other oxidizing
agents can produce ozone and photochemical oxidant pollution. Such pollution occurs in areas where
sunlight is intense, emissions of nitrogen oxides and volatile organic compounds (VOCs) are high, and
atmospheric conditions impede regional air circulation. Some chemicals emitted from non-hazardous
industrial waste management units could contribute to the total emissions of volatile organics in some
locations. As shown in Exhibit 4-2, many potentially reactive VOCs have been found as constituents
of non-hazardous industrial wastes. This contribution, however, appears to be quite small. Recent
emissions studies33 have shown that, in most municipal areas where photochemical pollution is a
problem, mobile and utility sources contribute the largest single portion of these emissions, with
emissions from other sources generally contributing a smaller amounts. Thus, the Agency did not
pursue this issue further as a potential gap in the hazardous waste characteristics.
5.3.8 Water Pollution
Based on information reported to EPA by States, Tribes, and other jurisdictions with water
quality responsibilities, about 40 percent of the Nation's surveyed rivers, lakes, and estuaries are not
clean enough for basic uses such as fishing or swimming. Polluted runoff from rainstorms and
snowmelt is the leading cause of this impairment. As seen below, the causes of this damage are
highly varied.
Rivers. Runoff from agricultural lands is the largest source of pollution for
rivers. Municipal sewage treatment plants, storm sewers/urban runoff, and
resource extraction also are among the leading sources. Bacteria, which can
cause illnesses in swimmers and others involved in water-contact sports, are
the most common pollutants impacting rivers. Siltation, nutrients (such as
phosphates and nitrates),35 oxygen-depleting substances, and metals are the
other leading causes of river pollution.
Lakes. As with rivers, runoff from agricultural lands is the largest source of
pollution. Municipal sewage treatment plants, storm sewers/urban runoff, and
unspecified nonpoint sources also lead the list. Leading causes of lake
pollution are nutrients, siltation, oxygen-depleting substances, metals, and
suspended solids.
Estuaries. Storm sewers and urban runoff are the leading sources of pollution
in estuaries. Municipal sewage treatment plants, agriculture, industrial point
"sources, and petroleum activities also lead the list. Nutrients, such as
phosphates and nitrates, are the most often reported pollutant in estuaries.
33 U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, National Air Quality
and Emission Trends Report 1991. EPA 454/R-95-014, October 1995.
34 U.S. Environmental Protection Agency, Office of Water, National Water Quality Inventory Report to
Congress, 1994.
35 In excess, nutrients can create a chain of impacts that include algal blooms, fish kills, foul odors, and weed
growth.
Page 5-15
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Other leading causes of pollution are bacteria, oxygen-depleting substances,
and oil and grease.
Although non-hazardous industrial wastes contribute to this pollution to some degree (e.g., via
sewage treatment and industrial point and non-point sources), it is unclear whether this contribution
constitutes an actual gap in the hazardous waste characteristics. For example, significant changes in
EPA's definition of solid waste would be needed before the hazardous waste characteristics could be
used to prevent some of these wastes from entering surface waters and resulting in risks or damage.
Industrial wastewaters that are point source discharges subject to regulation under the Clean Water Act
are exempt from the definition of solid waste.36 Many of the wastes from agriculture - one of the
largest contributors to water pollution from runoff - are exempt from the definition of hazardous waste
(although they are solid wastes).37 Alternatively, EPA could increase controls on point and non-
point sources of water pollution via other programs.38 Thus, for purposes of the hazardous
characteristic scoping study, EPA does not plan to research this area further at this time.
4£ ,^_
30 40 CFR 261.4(a)(2). This exemption applies only to the actual point source discharge. It does not exclude
industrial wastewater while they are being collected, stored, or treated before discharge; nor does it exclude sludges
generated by industrial wastewater treatment.
Q*7 __
31 40 CFR 261.4(b). This exemption applies to wastes that are returned to the soil as fertilizers, such as animal
manures and the unused portion of crops.
OQ
Some of these controls currently are being implemented. For example, a recent final National Pollutant
Discharge Elimination System (NPDES) storm water multi-sector general permit was published for industrial
activities (60 Federal Register 50803, September 29, 1995).
Page 5-16
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CHAPTER 6. STATE EXPANSIONS OF THE TOXICITY
CHARACTERISTIC AND LISTINGS
States may adopt hazardous waste regulations that are broader or more stringent than federal
RCRA Subtitle C regulations. A number of states have done so by regulating additional wastes as
hazardous. For example, states have:
Expanded the ignitability, corrosivity, or reactivity (ICR) characteristics;
Expanded the toxicity characteristic (TC);
Listed wastes as hazardous that are not hazardous under the federal rules; and
Restricted exemptions from the federal program.
These expansions beyond the federal hazardous waste identification rules reflect state judgments about
gaps in the federal program and thereby constitute potential gaps that may merit further investigation.
EPA has identified examples of such expansions by using readily available information on
state hazardous waste identification rules. In 1992, the EPA Office of Solid Waste examined state
hazardous and non-hazardous industrial waste programs in 32 states. The study identified "state
only" hazardous wastes, as well as high-risk designations for non-hazardous wastes. For the purposes
of this Scoping Study, EPA used data from this report and briefly reviewed current hazardous waste
regulations of eight states: California, Michigan, New Hampshire, Oregon, Rhode Island, Texas,
Washington, and New Jersey.
The first three sections of this chapter address state expansion of the TC, state only hazardous
waste listings, and state restrictions on exemptions from the federal regulations, respectively. (State
expansions of the ICR characteristics are addressed in Chapter 3.) In addition, Section 6.4 summarizes
the findings of the chapter.
6.1 State Expanded Toxicity Characteristics
States have expanded the federal toxicity characteristic by:
Adding constituents to the list of TC analytes;
Establishing regulatory levels for TC analytes that are more stringent than
federal levels;
Specifying alternative tests for identifying toxic hazardous waste; and
Using alternative approaches (other than listing constituents and regulatory
levels) to identify toxic hazardous wastes.
1 U.S. Environmental Protection Agency, Office of Solid Waste, Identifying Higher-Risk Wastestreams in the
Industrial D Universe: The State Experience, draft prepared by Science Applications International Corporation
and Kerr & Associates, Inc., July 30, 1993.
Page 6-1
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California, Michigan, and Washington have added constituents to the list of TC analytes, as
shown in Exhibit 6-1. Both California and Michigan have added zinc, and both California and
Washington have added PCBs.2 Other additional constituents include certain metals, pesticides,
dioxins, and potential carcinogens. An example of a state regulatory level that is lower that the federal
TC level is California's regulatory level of 1.7 mg/1 for pentachlorophenol (versus 100 mg/1 under the
federal TC).
As discussed in Section 3.6, California requires use of the Wet Extraction Test (WET) in
addition to the TCLP. Use of the WET test identifies several metal-containing wastes as hazardous
that are generally not identified as hazardous using the TCLP. These wastes include spent catalysts
from the petroleum refining and food industries and metal dusts, metal sludges, and baghouse wastes
from industries including fabricated metals, leather and apparel, electric and electronic products,
primary metals, motor vehicles, transportation equipment, chemicals and allied products, and others.3
Both California and Washington have established toxicity criteria for wastes based on acute
oral LD50, acute dermal LD50, acute inhalation LC50, and acute aquatic 96-hour LC50 (see
Exhibit 6-2). A waste is designated hazardous if a representative sample of the waste meets any of the
acute toxicity criteria. For example, Washington specifies rat and fish (for acute aquatic toxicity)
bioassay tests in a State test methods manual. Generators must either test a representative sample of
the waste or use their knowledge of waste constituents and the literature regarding toxicity of those
constituents to determine if the waste meets any of the acute toxicity criteria.
Finally, California's regulations state that a waste exhibits the characteristic of toxicity if the
waste, based on representative samples, "has shown through experience or testing to pose a hazard to
human health or environment because of its carcinogenicity, acute toxicity, chronic toxicity,
bioaccumulative properties or persistence in the environment" (22 CCR 66261.24(a)(8)). This broad
provision tends to shift the burden of identifying toxic wastes to the generator, because in the absence
of specific state criteria (e.g., constituents and regulatory levels) the generator is responsible for being
aware of experience or tests that show a waste poses a hazard.
63. State Only Listings
In addition to expanded characteristics, some states have listed state only hazardous wastes.
The most common state-only listed wastes are PCBs and waste oil. At least four states include
additional "F" Wastes; three include additional "K" wastes; five include additional "P" wastes; and six
include additional "U" wastes. Examples of state listed wastes include but are not limited to the
following:4
2 New Jersey had also added a TC regulatory level for PCBs, but the State recently adopted the federal
regulations by reference and will now use the same characteristics and listings as the federal program. A number
of states have added PCB wastes to their hazardous waste listings.
3 Identifying Higher-Risk Wastestreams in the Industrial D Universe: The State Experience, supra footnote 1
at pages 20A-B.
4 Ibid., pages 8-14.
Page 6-2
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Exhibit 6-1
State Toxicity Characteristics:
Additional Constituents and More Stringent Regulatory Levels
CALIFORNIA
Constituent
antimony
aldrin
asbestos
beryllium
chromium (VI)
chromium (HI)
cobalt
copper
DDT, DDE, DDD
2,4-dichlorophenoxyacetic acid
dieldrin
dioxin (2,3,7,8-TCDD)
fluoride salts
kepone
lead compounds, organic
mirex
molybdenum
nickel
pentachlorophenol
PCBs
thallium
2,4,5-trichlorophenoxypropionic
acid
vanadium
zinc
Regulatory Level (mg/1 in leachate unless
otherwise noted)
15
0.14
1 percent
0.75
5
560
80
25
0.1
10
0.8
0.001
180
2.1
13 mg/kg
2.1
350
20
1.7 (lower regulatory level than federal)
5
7
1
24
250
Any of the following substances at a single or combined concentration equal to or
exceeding 0.001 percent by weight:
2-acetyiaminofluorene (2-AAF)
acrylonitrile
4-aminodiphenyl
benzidine and its salts
bis(chloromethyl) ether (BCME)
methylchloromethyl ether
1,2-dibromo-3-chloropropane
(DBCP)
beta-propiolactone (BPL)
3,3,-dichlorobenzidine and its salts (DCB)
4-dimethylaminoazobenzene
ethyleneimine (EL)
alpha-naphthylamine (1-NA)
beta-naphthylamine (2-NA)
4-nitrobiphenyl
n-nitrosodimethylamine (DMN)
vinyl chloride (VCM)
Page 6-3
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Exhibit 6-1 (continued)
State Toxicity Characteristics:
Additional Constituents and More Stringent Regulatory Levels
MICHIGAN
Constituent
aflatoxin
copper
dioxin (1,2,3,4,7,8-HxCDD)
dioxin (1,2,3,6,7,8-HxCDD)
dioxin (1,2,3,7,8,9-HxCDD)
dioxin (1,2,3,7,8-PoCDD)
dioxin (2,3,7,8-TCDD)
furan (2,3,7,8-TCDF)
zinc
WASHINGTON
Constituent
PCBs
Regulatory Level (mg/1)
1
100
1
1
1
1
1
1
500
Regulatory Level (mg/1)
2
Exhibit 6-2
State Toxicity Criteria Applied to Whole Waste
(Representative Sample)
CALIFORNIA
acute oral LD50
acute dermal LD50
acute inhalation LC50
acute aquatic 96h LC50
WASHINGTON
acute oral LD50
acute dermal LD50
acute inhalation LC50
acute aquatic 96h LC50
RHODE ISLAND
acute oral LD50
OREGON
< 5,000 mg/kg
< 4,300 mg/kg
< 10,000 ppm
< 500 mg/1
< 5,000 mg/kg
< 20,000 mg/kg
< 200 mg/1
< 1,000 mg/1
< 5,000 mg/kg
acute aquatic 96h LC50 < 250 mg/1 (only includes certain pesticide residues)
Page 6-4
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In California, wastes containing any of almost 800 listed materials are
presumed hazardous, unless proven through testing not to exhibit any of
California's criteria for identifying hazardous waste.
Maine has listed certain wastes from the production of linuron and bromacil,
and has listed proposed additions to the federal list of hazardous wastes.
Maryland has listed 9 specific chemical warfare agents.
Michigan has added certain chemical production wastes to its "K" or specific
source list, and has listed many state-only "U" wastes including organics,
inorganics in particle form, Pharmaceuticals (e.g., phenobarbital), chemical
warfare agents, and herbicides.
New Hampshire has added a number of wastes to its "F" or non-specific
source list, including certain wastes from industrial painting operations and
from metals recovery operations.
Oregon has listed certain pesticide residues and certain blister agents and nerve
gas.
6.3 State Restrictions on Exemptions
Another way that states have expanded the universe of wastes they regulate as hazardous is by
choosing not to adopt exemptions in the federal regulations. Examples include but are not limited to
the following:5
Colorado does not recognize exemptions for certain injected groundwater that
exhibits the TC and is reinjected pursuant to free phase hydrocarbon recovery
operations at petroleum facilities (40 CFR 261.4(b)(ll)), certain used
chlorofluorocarbon (CFC) refrigerants that are reclaimed for further use (40
CFR 261.4(b)(12)), or non-terne plated used oil filters (40 CFR 261.4(b)(13)).
Connecticut, New Hampshire, Oregon, and Washington do not include
exemptions for certain chromium-bearing wastes from leather tanning and
finishing (40 CFR 261.4(b)(6)(ii)).
Maine does not recognize exemptions at 40 CFR 261.4(b)(6) through (13).
-These include: '
TC chromium wastes where chromium in the waste is nearly
exclusively trivalent chromium;
certain chromium-bearing wastes from leather tanning and finishing;
specified mining and mineral processing wastes;
cement kiln dust;
certain arsenical-treated wood wastes;
petroleum contaminated media and debris that fail the TC;
Ibid.
Page 6-5
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certain injected groundwater;
used CFC refrigerants; and
non-teme plated used oil filters.
Massachusetts, New York, and North Dakota do not recognize exemptions at
40 CFR 261.4(b)(10) through (13). (These wastes include the last four wastes
named directly above.)
6.4 Summary
Some states appear to be regulating a significant number of wastes as hazardous that are not
covered under federal RCRA regulations. Moreover, a few states have taken different approaches to
identifying characteristic hazardous wastes. In particular, California and Washington regulations go
beyond constituent-by-constituent definitions and apply acute toxicity criteria to the whole waste.
State expansions of hazardous waste identification regulations reflect state judgment about gaps in the
federal program. State expansions have filled these gaps, but only in the specific states with such
expansions. Such potential gaps apparently are not being filled in the remaining states that have not
expanded the federal hazardous waste definitions.
Page 6-6
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CHAPTER 7. SUMMARY OF POTENTIAL GAPS
This chapter reviews the broad categories of potential gaps identified in the previous three
chapters. Different ways of organizing the potential gaps are discussed, and a single comprehensive
list of the potential gaps is presented.. This review lays the groundwork for evaluating the significance
of the potential gaps in the following three chapters.
7.1 Organization of the Analysis of Potential Gaps
EPA has identified five categories of potential gaps in the hazardous waste characteristics
using different approaches in each area:
ICR Characteristics. EPA identified potential gaps associated with these
characteristics by reviewing the original 1980 rulemaking record and
comparing the ICR definitions and test methods to approaches taken to
controlling similar hazards under other federal and state regulatory schemes.
TC Characteristic. The Agency identified potential gaps associated with this
characteristic by examining the properties of the TC analytes to determine how
they could pose hazards to human health or the environment.
Non-TC Chemicals. In contrast with the prior step, EPA began with a set of
properties (including the potential to appear in non-hazardous industrial wastes)
and then identified individual chemicals and groups of chemicals that could
constitute potential gaps in the characteristics.
Natural Resource Damages and Large-scale Environmental Problems. The
Agency examined evidence of possible gaps using a hybrid approach that
considered potential gap chemicals on the basis of their hazardous properties
(e.g., endocrine disruption, stratospheric ozone depletion) and reviewed other
potential gaps starting from possible risks to the environment, which, in turn,
implied that certain waste constituents might be of concern.
State Expansion of TC and State Listings. EPA reviewed how states have
expanded their TC and listed as hazardous certain wastes that are not
hazardous under the federal rules. These expansions reflect state judgments
"about gaps in the federal rules and thereby constitute potential gaps for this
Scoping Study.
The potential gaps presented in the following section are organized primarily by the major
categories identified above. Where appropriate, these categories are subdivided into groups of
chemicals posing similar types of hazards, and occasionally are subdivided even further by specific
hazardous properties or exposure pathways of concern. Some of the potential gaps overlap. For
example, endocrine disrupters appear among the concerns associated with the non-TC analytes as well
as in a category by themselves under large-scale environmental risks. Although this overlap is
inevitable, the potential gaps have been organized so as to minimize it, without omitting any
potentially significant gaps.
Page 7-1
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EPA considered other methods of classifying the potential gaps for purposes of further
analysis. Gaps could be identified, for example, in terms of individual chemicals and their specific
properties and hazards. Alternatively, the gaps could be organized around groups of chemicals with
specific hazardous properties or types of risks. EPA rejected these approaches for purposes of this
Scoping Study as impractical because too many individual chemicals or groups of chemicals, risks,
and pathways are involved. In addition, defining potential gaps in categories that do not parallel the
approaches used to identify such gaps would make it more difficult to appreciate the evidence and
uncertainty associated with each potential gap.
7.2 Summary of Potential Gaps
Exhibit 7-1 lists the potential gaps in the hazardous waste characteristics identified by EPA in
the preceding chapters. The individual gaps are organized according to the section or chapter in which
they are discussed, with reference to specific chemical classes, exposure pathways, or types of risks, as
appropriate. Potential gaps are evaluated in the following chapters in order to assess their potential
significance in terms of potential risks to health and the environment. Because of data limitations,
most of this evaluation focuses on potential gaps associated with the TC analytes and other chemicals.
Chapter 8 examines the relationship between potential gaps, specific industries, and waste management
methods. Chapter 9 discusses the extent to which the various potential gaps may already be addressed
to some extent by existing regulatory systems. Finally, Chapter 11 presents a Summary evaluation of
the potential gaps against a number of risk and regulatory criteria.
Exhibit 7-1. Summary of Potential Gaps in the Hazardous Waste Characteristics
Category of Potential Gap
Potential Gaps in the ICR
Characteristics
(Sections 3.2 to 3.4)
Potential Gaps Associated
With the TC Analytes
(Sections 3.5 and 3.6)
Nature of Potential Gap
Ignitability
Exclusion of DOT combustible liquids
Exclusion of aqueous flammable liquids
References outdated DOT regulations
No test method for non-liquids
Corrosivity
Exclusion of corrosive non-liquids
pH limits are potentially not protective
pH test methods are not predictive of risk
Corrosion of non-steel materials is not addressed
Solubilization of non-metals is not addressed
Exclusion of irritants and sensitizers
Reactivity
Definition is broad, non-specific
References outdated DOT regulations
No test methods are specified
Groundwater Pathwav Risks
DAF values potentially not protective
Page 7-2
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Exhibit 7-1. Summary of Potential Gaps in the Hazardous Waste Characteristics (continued)
Category of Potential Gap
Nature of Potential Gap
Potential Gaps Associated
With the TC Analytes
(Sections 3.5 and 3.6)
(continued)
Ecological Risks Not Addressed
Potent ecological toxicants
Persistent/bioaccumulative pesticides
Non-Groundwater Pathways Not Addressed
Inhalation (volatile organics)
Surface water pathway
Indirect/food chain (volatile, persistent, and bioaccumulative
chemicals)
TCLP Limitations
May not accurately predict leachate concentration or risks for
certain wastes and units
Potential Gaps Associated
with Known and Possible
Constituents of
Non-hazardous Industrial
Waste odier than TC
Analytes (Chapter 4)
Major Constituents/Properties of Non-Hazardous Industrial Wastes
Not Addressed
Metals/inorganics
groundwater pathway
Volatile chlorinated organics
~ groundwater and inhalation pathway exposures
Volatile hydrocarbons
groundwater and inhalation pathways
Other volatile organics
groundwater and inhalation pathways
Pesticides and related compounds
- inhalation and indirect food chain pathways
Phthalate esters
indirect pathways
Phenolic compounds
groundwater and indirect pathways
Polycyclic aromatic hydrocarbons
indirect pathway exposures
Other semivolatile organic compounds
all pathways
Generation of LNAPLs and DNAPLs
Facilitated transport of organic chemicals
Long-lasting and difficult to remediate
Page 7-3
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Exhibit 7-1. Summary of Potential Gaps in the Hazardous Waste Characteristics (continued)
Category of Potential Gap
Nature of Potential Gap
Potential Gaps Associated
with Natural Resource
Damages and Large-Scale
Environmental Problems
(Chapter 5)
Natural Resource Damages
Groundwater resource damage without health risks
Odors
Large-scale Environmental Problems
Air deposition to the Great Waters
Airborne particulates
Global climate change
Potential damage from endocrine disrupters
Red tides
Stratospheric ozone depletion
Tropospheric ozone and photochemical pollution
Water pollution
Potential Gaps Associated
with State Expansion of TC
and Listings (Chapter 6)
State Expansion of TC
Additional TC constituents
More stringent regulatory levels
Alternative test methods
Use of acute oral, dermal,' inhalation, and aquatic LD50 or LC50
criteria applied to representative samples of waste
State Only Listings
State Restrictions on Federal Exemptions
Page 7-4
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CHAPTER 8. POTENTIAL GAPS AS FUNCTION OF
INDUSTRY AND WASTE MANAGEMENT METHODS
This Chapter evaluates the significance of potential gaps by linking the known and possible
non-hazardous industrial waste constituents to specific industries and management practices. It is
organized as follows:
Section 8.1 describes the primary data sources used in this chapter and their major
limitations;
Section 8.2 discusses the amount of non-hazardous industrial wastes generated by
various industries and the constituents found in their wastes; and
Section 8.3 reviews the methods of managing non-hazardous industrial wastes and the
associated risks to human health and the environment.
8.1 Data Sources and Major Limitations
Over the past 15 years, EPA has made several substantial efforts to gather information on the
types and amounts of non-hazardous industrial wastes generated by specific industries and the
management methods used for specific wastes. Despite these efforts, significant gaps, inconsistencies,
and other limitations remain in the available information. Considerably fewer data are available on
non-hazardous industrial wastes than on hazardous wastes, in part, because of the limited federal role
in regulating non-hazardous industrial wastes and the lack of widespread reporting requirements.
The major sources of data on non-hazardous industrial waste generation and management are .
as follows:
Industrial Studies Database (ISDB). EPA has maintained the ISDB since
1982. The database contains information on waste generation, management,
and point-of-generation constituent concentrations for 16 industries. The
sources of the information include RCRA Section 3007 questionnaires, plant
visit reports, sampling and analysis site visit reports, engineering analysis
reports, and data collected for hazardous waste listing decisions.
« The Industrial Subtitle D Telephone Screening Survey. This survey was
conducted between November 1986 and April 1987. Over 18,000 facilities in
17 industry sectors were questioned about the quantities and types of non-
hazardous industrial wastes generated and managed on-site in 1985, the
number and design of on-site management units, and the amounts of such
waste managed in on-site landfills, surface impoundments, waste piles, and
land application units.
National Survey of Treatment, Storage, Disposal, and Recycling Facilities
(TSDR Survey). The TSDR Survey was conducted in 1986 to gather
information on waste generation and management practices for 1986 and any
projected changes in waste management capacity prior to 1992. The Survey
questioned approximately 2,500 facilities that manage hazardous waste on-site,
Page 8-1
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including the 2,400 RCRA-permitted or interim status treatment, disposal, or
recycling facilities, and approximately 100 of the 700 storage facilities. The
Survey addressed both hazardous and non-hazardous waste management at
these hazardous waste management facilities. This data source provided
information related to non-hazardous industrial waste management practices
and waste generation by industry groups.
Background documents for recent Agency listings decisions. Reports prepared
for the Agency's proposed decision not to list certain dyes and pigments
wastestreams as hazardous and the proposed decision not to list certain solvent
wastestreams as hazardous. The document identifies the industries responsible
for these wastestreams.
In addition, this Chapter uses data from the 1992 Toxic Release Inventory (TRI) on the amount of
certain toxic substances released to land or injected underground by various industries. This data
source is discussed in Section 8.2.4. At the time this Study was prepared, facility-specific data from
the 1994 TRI were not available. Therefore, 1992 TRI data were used in this chapter. While the use
of 1992 instead of more recent TRI data will not significantly affect the analysis, it will limit the
results to a smaller set of chemicals and will not reflect recent pollution prevention progress.
The first three data sources have the disadvantage of being relatively old. They reflect non-
hazardous industrial waste generation and management practices prevalent a decade or more ago.
Since then, patterns of waste generation and management are likely to have changed in some
significant ways in response to the implementation of RCRA hazardous waste regulations and other
federal and state programs. In addition, the ISDB is rather limited in the number of facilities surveyed
in each industry sector, particularly with regard to organic analytes. The ISDB and Telephone
Screening Survey also address only certain industries.
The data sources are not entirely consistent. For example, the estimates of non-hazardous
industrial waste generation for similarly defined industry groups often differ substantially among the
sources. These inconsistencies arise, in part, from the use of different data collection and
summarization methods. In the analyses discussed below, the Agency has used what it considers to be
the most reliable and complete data concerning waste generation and management from these sources.
EPA has previously analyzed the data from the first three data sources to investigate various
aspects of non-hazardous industrial waste generation and management practices. Most of the data
presented below come from two of these studies, the "Industrial D Industry Profiles"1 and the 1988
"Report to Congress: Solid Waste Disposal in the United States."2 The former document summarizes
non-hazardous industrial waste generation and management practices in 25 industry sectors, while the
latter source focuses on the land disposal of all non-hazardous solid waste covered by the RCRA
Subtitle D criteria.
1 Systems Applications International Corporation, August 8, 1992, draft.
2 U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, October 1988.
Page 8-2
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8.2 Potential Gaps as a Function of Industry/Waste Source
This section discusses non-hazardous industrial waste generation by various industries as
follows:
Section 8.2.1 reviews available data on the volume of such waste generated by
specific industries or industry groups;
Section 8.2.2 compares these data with the industries responsible for the releases documented
in Chapter 2;
Section 8.2.3 identifies the industries responsible for generating non-hazardous industrial
wastes containing constituents with the highest risk of adverse human health
effects; and
Section 8.2.4 identifies the industries with facilities reporting TRI releases to land and
underground injection of known or possible non-hazardous industrial waste
constituents.
8.2.1 Non-Hazardous Industrial Waste Generation by Industry
In 1988, the Agency estimated that approximately 7.6 billion tons of non-hazardous industrial
waste was generated and managed on-site annually in the United States.3 Approximately 68 percent
of this waste came from four major industry groups:
Paper and allied products (SIC 26): 2.25 billion tons (29.6 percent);
Chemicals and allied products (SICs 2812-2819, 2821, 2824, 2851, 2891,
2865, 2869, and 287): 1.39 billion tons (18.2 percent);
Primary metals industries (SICs 3312-3321 and 3331-3399): 1.37 billion tons
(18.0 percent); and
Petroleum refining and related industries (SIC 29): 168 million tons (2.2
percent).
On the basis of the amounts of waste generated and risk-based screening of waste constituents,
the Office of Solid Waste identified these four industry groups as "priority industries" for possible
further regulation. Other industries that generate more non-hazardous industrial wastes than petroleum
refining were not identified as priority industries on the basis of risk-based screening of waste
constituents. Exhibit 8-1 summarizes the estimates of non-hazardous industrial waste generation for
the four priority industries and corresponding industry sectors and for other relatively high volume
industries and sectors.
Ibid., p.2. This volume may include some special wastes, such as in the primary metals or electrical power
generation industries.
Page 8-3
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Exhibit 8-1
Estimated Generation of Non-Hazardous Industrial Waste by Major Industry Group
Industry Group
Paper and Allied Products
Primary Metals Industry3
Primary Iron and Steel
Primary Non-ferrous Metals
Chemicals and Allied Products5
Industrial Inorganic Chemicals
Fertilizer and Agricultural Chemicals
Plastics and Resins Manufacturing
Industrial Organic Chemicals
Electric, Gas, and Sanitary Services0
Electric Power Generation
Water Treatment
Stone, Clay, Glass, and Concrete
Food and Kindred Products
Textile Manufacturing
Petroleum Refining
Rubber and Miscellaneous Products
Transportation Equipment
Leather and Leather Products
SIC
26
33
332
333
28
281
287
282
286
49
4911
4941
32
20
22
29
30
37
31
Total On-site
Generation (thousand
tons/yr.)
2,251,700
1,367,611
1,300,541
67,070
1,324,722
919,725
165,623
180,510
58,864
1,151,123
1,092,277
58,846
621,974
373,517
253,780
168,632
24,198
12,669
3,234
Source: U.S. Environmental Protection Agency, "Report to Congress: Solid Waste Disposal in the
United States," Volume n, Table 3-5, October 1988.
a The Primary Metals Industry includes only SICs 332 (Primary Iron and Steel) and 333 (Primary
Non-ferrous Metals).
b Chemicals and Allied Product Industry includes only SICs 281 (Industrial Inorganic Chemicals),
282 (Plastics and Resins Manufacturing), 286 (Industrial Organic Chemicals), and 287 (Fertilizer and
Agricultural Chemicals).
c Electric, Gas, and Sanitary Services Industry includes only SICs 4911 (Electric Power
Generation) and 4941 (Water Treatment).
Page 8-4
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The listing documents for solvent wastes and wastes from the dye and pigment industries are
another source of information on non-hazardous industrial waste. All of the information related to
waste volumes and constituents concentrations for the dye and pigment industries, however, was
claimed proprietary by the submitters and, therefore, could not be included in this Study. EPA
recently identified non-hazardous industrial solvents in developing a recent proposed rulemaking. The
amounts of solvent wastes have not been broken down by industry and, therefore, could not be
included in Exhibit 8-1.
8.2.2 Industries Responsible for Documented Non-Hazardous Industrial Waste Releases
The environmental release descriptions discussed in Chapter 2 provide additional evidence
about the industries (and waste management practices) associated with potential gaps in the
characteristics. Exhibit 8-2 tabulates, by industry, the frequency of documented releases and their
exceedence of health-based or ecologically-based regulatory standards. As shown in this exhibit, some
of the industries that show up frequently in the release descriptions are among the high-volume
industries identified above. The most frequently occurring industry group in the release descriptions is
electric, gas, and sanitary services (SIC 49) with all of those release descriptions originating in the
refuse systems sector (SIC 4953). This industry sector includes commercial waste management
facilities. As noted in Chapter 2, most of these commercial non-hazardous industrial waste
management units are located in California, where considerable monitoring data were available. From
these data, EPA could not determine the industries that generate the wastes managed by these
commercial facilities.
The next three industry groups with the most documented releases are the paper and allied
products (27 releases), chemicals and allied products (11 releases), and food and kindred products (10
releases). These industry groups also are among the largest generators of non-hazardous industrial
waste. The primary metals industry, another high-volume group, also has a moderate number of
documented releases; they account for 6 of the 112 total releases documented in Chapter 2.
Exhibit 8-2 also shows the numbers of documented releases at which the maximum detected
concentrations of constituents exceeded health-based or ecologically-based standards.4 All but six of
the 101 releases with data on the standards exceeded had exceedences of health- or ecologically-based
standards.5 These six releases exceeded secondary maximum contaminant levels (SMCLs) only.
Sixty-five of these releases also violated other standards.
Exhibit 8-3 shows the total numbers of times particular chemicals were found in the release
descriptions for various industry sectors. (The totals are the sums of the number of individual
chemicals detected at each site, counting all chemicals for each site, even if a chemical is detected at
more than one site. For example, the total detections at two sites having 10 chemicals each, 3 of
which are the same, is 20, not 17.) In addition, the exhibit shows the numbers of times such
4 Health-based or ecologically-based standards included Primary MCLs, MCLGs, and state standards established
to protect health or the environment. Non-health-based or non-ecologically-based standards are those set to preserve
groundwater usability or aesthetics, such as Secondary MCLs or standards for which any health or ecological bases
were not explained.
5 EPA lacks information on the regulatory standards that were exceeded for all releases from California and for
two releases from other states. All releases described in this Study, however, were documented to have exceeded
one or more applicable federal, state, or local regulatory standards.
Page8-5
-------
Exhibit 8-2
Chemicals Exceeding Health-Based and Non-Health-Based Regulatory Levels
in the Release Descriptions for Non-Hazardous Waste Management
Industry Group (SIC)
Electric, Gas, and Sanitary Services (49)
Paper and Allied Products (26)
Chemicals and Allied Products (28)
Food and Kindred Products (20)
Primary Metal Industries (33)
Nonmetallic Minerals, Except Fuels (14)
Petroleum Refining (29)
Fabricated Metal Products (34)
Transportation Equipment (37)
Agricultural Production Livestock (02)
Electronic and Other Electronic
Equipment (36)
Stone, Clay, and Glass Products (32)
Apparel and Other Textile Products (23)
Industrial Machinery and Equipment (35)
Instruments and Related Products (38)
Total
Number of Release Descriptions
Total3
35
27
11
10
6
4
4
3
3
2
2
2
1
1
1
112
With Both
Health/
Ecological and
Non-Health/
Non-Ecological
Exceedences
11
22
8
6
2
4
3
0
3
2
1
2
1
0
0
65
With Only
Health/
Ecological
Exceedences
' 11
4
3
3
4.
0
1
2
0
0
0
0
0
1
1
30
With Only
Non-Health/
Non-Ecological
Exceedences
4
1
0
0
0
0
0
1
0
0
0
0
0
0
0
6
a The total number of release descriptions in column 2 may not equal the sum of the release descriptions in
columns 3, 4, and 5. Column 2 includes all release descriptions for chemicals that were documented to have
exceeded at least one applicable federal, state, or local regulatory standard. Columns 3, 4, and 5 include only
those release descriptions in Column 2 for which supporting data indicate which regulatory standards were
exceeded. Information was not available on the regulatory standards that were exceeded for all releases from
California and for two releases from other states.
Page 8-6
-------
Exhibit 8-3
Numbers of Chemical Detections and Frequencies of Regulatory Exceedences in Release Descriptions
Industry Group (SIC)
Electric, Gas, and Sanitary Services (49)
Paper and Allied Products (26)
Chemicals and Allied Products (28)
Food and Kindred Products (20)
Primary Metal Industries (33)
Nonmetallic Minerals, Except Fuels (14)
Petroleum Refining (29)
Fabricated Metal Products (34)
Transportation Equipment (37)
Agricultural Production-Livestock (02)
Electronic and Other Electronic Equipment (36)
Stone, Clay, and Glass Products (32)
Apparel and Other Textile Products (23)
Industrial Machinery and Equipment (35)
Instruments and Related Products (38)
Total
Number of
Release
Descriptions
35
27
11
10
6
4
4
3
3
2
2
2
1
1
1
112
Chemical Detections
Total
350
340
250
72
58
91
40
12
48
18
16
33
3
7
2
1,340
Mean Per
Release
10
13
23
7
10
23
10
4
16
9
8
17
3
7
2
Regulatory
Exceedences
Total
91
148
97
22
27
49
16
7
19
8
4
14
3
3
1
509
Mean Per
Release
3
5
9
2
5
12
4
2
6
4
2
7
3
3
1
Health- or
Ecologically-Based
Exceedences
Total
58
85
73
13
24
34
8
5
14
5
1
10
2
3
1
336
Mean Per
Release
2
3
7
1
4
9
2
2
5
3
0
5
2
3 '
1
Page 8-7
-------
chemicals were detected above regulatory levels, and the proportions of chemicals found above health-
based or ecologically-based standards. The 3 industries with the most releases", electric, gas, and
sanitary services (35 releases), paper and allied products (27 releases), and chemicals and allied
products (11 releases), also had the highest numbers of chemical .detections (350, 340, and 250,
respectively). The average number of chemicals detected per facility varies substantially across
industries. For example, the 3 industries noted above had means of 10, 13, and 23 chemicals detected
per release, respectively. The average number of regulatory and health- or ecologically-based
exceedences per release also varies greatly across industries. For example, the electric, gas, and
sanitary services industry averages only 3 regulatory and 2 health- or ecologically-based exceedences
for every 10 chemical detections. In contrast, the chemical industry averages 9 regulatory and
7 health- or ecologically-based exceedences for every 23 chemical detections.
8.2.3 Occurrence of High-Hazard Industrial Waste Constituents by Industry
Another indicator of the potential severity of hazards associated with releases from non-
hazardous industrial waste management in various industries is the frequency of occurrence of waste
constituents with the highest risk to humans. Exhibit 8-4 identifies the chemicals that appeared most
frequently in the release descriptions, the number of total appearances, and the number of times the
chemical was present in groundwater above regulatory or other health-based levels based on 10"5
cancer risks or a hazard quotient greater than 1.0. As noted in Section 5.1, many of the most
frequently occurring chemicals do not have health-based or ecologically-based standards, but may have
SMCLs or other regulatory levels. Among these are the three most common constituents found in the
release descriptions: iron, chloride, and sodium, as well as manganese, zinc, calcium, magnesium,
potassium, copper, aluminum, and silver.
A substantial number of potentially toxic chemicals were detected in the release descriptions.
For example, 11 of the 52 most frequently detected chemicals are known or suspect carcinogens by
ingestion or inhalation.6 Only one of the most frequently detected chemicals (phosphorous) is
identified as having a low RfD, although several other chemicals on the list are generally considered
toxic, including lead, mercury, cadmium, arsenic, and chromium. Seven of the most frequently
detected chemicals are chlorinated volatile organics, with trichlorethylene, occurring most often
(17 times). While all of the inorganic analytes appearing on the list are persistent, none of the most
frequently occurring organic chemicals were identified as persistent in Chapter 4. In fact, none of the
persistent bioaccumulative chlorinated pesticides identified as posing potentially high risks are seen in
the release descriptions more than three times and most were seen in only one release description.
Exhibit 8-5 shows the number of occurrences and the number of regulatory, health-based, or
ecologically-based exceedences for the constituents detected most frequently in the release descriptions
for each industry group. -For each group, the 15 most frequently detected chemicals or all detected
chemicals are shown, whichever is smaller. In almost all industry groups, inorganic chemicals are
found more often than organics. This finding may be due, in part, to a lack of analytical data for
organic chemicals in some industries. Volatile organic chemicals are rarely found among the most
frequently detected chemicals, with a few exceptions. Iron, manganese, and sulfate were among the
most frequently found chemicals in the electric, gas, and sanitary services release descriptions, and
volatile organics represent the bulk of the most frequently detected chemicals for the electronic and
other electronic equipment industry and the petroleum refining industry. The relative scarcity of
' These are chemicals that were identified as having Cancer Slope Factors or Unit Risks in IRIS or HEAST.
Page 8-8
-------
Exhibit 8-4
Most Frequently Occurring Constituents in the Release Descriptions
Constituent
Number of Occurrences in
Release Descriptions
Number of Occurrences
Above Regulatory Levels or
HBLs3
TC Constituents
Lead
Chromium
Arsenic
Barium
Cadmium
Benzene
Mercury
Selenium
Trichloroethylene
Vinyl chloride
Silver
Chlorobenzene
Tetrachloroethylene
Chloroform
1 ,4-Dichlorobenzene
37
36
29
28
28
23
19
18
17
13
12
9
9
8
5
22
21
24
28
28
16
6
18
8
6
12
9
9
8
0
SMCL Constituents
Iron
Chloride
Manganese
Zinc
Copper
Aluminum (fume or dust)
Fluorides
54
52
39
33
17
12
12
49
32
39
33
17
12
4
Other Constituents
Sodium
Nitrates
Magnesium
Calcium
Potassium
40
33
32
30
21
8
30
3
0
0
Page 8-9
-------
Exhibit 8-4 (continued)
Most Frequently Occurring Constituents in the Release Descriptions
Constituent
Number of Occurrences hi
Release Descriptions
Number of Occurrences
Above Regulatory Levels or
HBLsa
Other Constituents (continued)
Toluene
Phenol
Ammonia
Calcium carbonate
Nickel
Dichloromethane
Nitrite
Ethylidene dichloride
Xylene (mixed isomers)
Acetone
Nitrogen
Beryllium
cis-1 ,2-Dichloroethylene
Ethylbenzene
Vanadium (fume or dust)
1 ,2-Dichloroethylene
Boron and compounds
Chloromethane
Cyanides
Phosphorus
1 ,2-Dichlorobenzene
Antimony
Carbon disulfide
Cobalt
Naphthalene
20
18
16
15
14
12
11
10
10
9
8
7
7
7
7
6
6
6
6
6
5
5
5
5
5
20
18
11
0
4
12
9
10
10
9
0
7
7
7
6
6
3
0
6
1
5
5
5
0
3
a Regulatory levels include MCLs, SMCLs, AWQCs, or other state Health- or ecologically-based standards.
HBLs are drinking water concentrations corresponding cancer risk of 10~5 or Hazard Quotient of 1.0 for an
adult, using IRIS or HEAST toxicity criteria.
Page 8-10
-------
Exhibit 8-5
Occurrence of Waste Constituents by Industry Group
Industry Group (SIC)
Paper and Allied Products (26)
Refuse Services (495)
Constituent
PH'
Chloride*
Iron*
Sulfate*
Sodium
Calcium carbonate
Calcium
Magnesium
Zinc*
TDS*
Chromium
Manganese*
Arsenic
Barium
Cadmium
pH*
Iron*
Manganese*
Sulfate*
Lead
Chloride*
Magnesium
Nitrate
TDS*
Trichloroethylene
Benzene
Calcium
Chromium
Sodium
Vinyl Chloride
Number of
Occurrences in
Release
Descriptions
22
21
21
20
15
12
11
11
11
10
9
9
8
7
7
19
14
13
13
12
11
10
10
10
10
9
9
9
9
9
Number of
Occurrences
Above
Regulatory,
Health- or
Ecologically-
based Levels
12
13
21
12
2
0
0
2
11
7
5
9
7
7
7 '
3
10
13
4
4
7
1
7
1
3
3
0
4
1
3
Page 8-11
-------
Exhibit 8-5 (continued)
Occurrence of Waste Constituents by Industry Group
Industry Group (SIC)
Chemicals and Allied Products (28)
Nonmetallic Minerals, Except Fuels (14)
Constituent
Benzene
Chromium
Iron*
Lead
Manganese*
Sulfate*
TDS*
Zinc*
Arsenic
Chloride*
Fluoride*
Total Organic Carbon
Acetone
Barium
Cadmium
Arsenic
Iron*
Lead
Manganese*
PH*
Cadmium
Chloride*
Copper*
Nickel
Potassium
Sodium
Sulfate*
Zinc*
Aluminum
Barium
Number of
Occurrences in
Release
Descriptions
7
7
7
6
6
6
6
6
5
5
5
5
4
4
4
4
4
4
4
4
3
. 3
3
3
3
3
3
3
3
2
2
Number of
Occurrences
Above
Regulatory,
Health- or
Ecologically-
based Levels
6
4
6
,4
6
4
4
6
5
1
1
1
4
4
4
2
4
4
4
2
3
3
3
1
0
0
3
3
2
2
Page 8-72
-------
Exhibit 8-5 (continued)
Occurrence of Waste Constituents by Industry Group
Industry Group (SIC)
Food and Kindred Products (20)
Primary Metal Industries (33)
Constituent
Nitrite
Nitrate
Nitrogen
pH*
TDS*
Total filterable residue
Calcium
Chloride*
Magnesium
Sodium
Sulfate*
Ammonia
Bicarbonate
Conductivity
Copper*
Lead
Chromium
Aluminum*
Arsenic
Barium
Cadmium
Chloride*
Conductivity
Mercury
Nickel
Zinc*
2,4,6-Trichlorophenol
2,4-Dichlorophenol
2,4-Dimethylphenol
2,4-Dinitrophenol
Number of
Occurrences in
Release
Descriptions
6
5
5
4
4
4
3
3
3
3
3
2
2
2
2
4
3
2
2
2
2
2
2
2
2
2
1
1
1
1
Number of
Occurrences
Above
Regulatory,
Health- or
Ecologically-
based Levels
4
5
0
0
3
0
0
2
0
2
2
1
0
0
2
4
3
2
2
2
2
2
0
0
2
2
0
1
1
1
Page 8-13
-------
Exhibit 8-5 (continued)
Occurrence of Waste Constituents by Industry Group
Industry Group (SIC)
Petroleum Refining (29)
Agricultural ProductionLivestock (02)
Constituent
Chloride*
Conductivity
Di-n-butylphthalate
Naphthalene
pH*
Sulfate*
TDS*
1 ,2-Dichloroethane
2-Methylnaphthalene
Acenaphthene
Acetone
Barium
Benzene
Carbon disulfide
Chlorobenzene
Ammonia
Nitrate
TDS*
Bicarbonate
Calcium
Chemical Oxygen Demand
Chlorine*
Iron*
Magnesium
Nitrite
Nitrogen
PH*
Phosphorus
Sodium
Toluene
Number of
Occurrences in
Release
Descriptions
3
2
2
2
2
2
2
1
1
1
1
1
1
1
1
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
Number of
Occurrences
Above
Regulatory,
Health- or
Ecologically-
based Levels
2
1
1
1
1
2
2
1
0
1
1
1
1
1
1
0
2
2
0
0
0
1
1
0
1
0
0
0
1
1
Page 8-14
-------
Exhibit 8-5 (continued)
Occurrence of Waste Constituents by Industry Group
Industry Group (SIC)
Transportation Equipment (37)
Electronic and Other Electronic Equipment (36)
Constituent
Phenol
Barium
Chromium
Total Organic Carbon
1 , 1 -Dichloroethane
2,4-Dimethylphenol
Aluminum*
Ammonia
Antimony
Arsenic
BEHP
Benzene
Beryllium
Cadmium
Calcium
1 , 1 -Dichloroethane
Carbon tetrachloride
Chloride*
Chloroform
Iron*
Manganese*
Methylene chloride
PH*
Phenolics
Sodium
Sulfate*
Tetrachloroethylene
Toluene
Total Organic Carbon
Total Organic Halogens
Number of
Occurrences in
Release
Descriptions
3
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Number of
Occurrences
Above
Regulatory,
Health- or
Ecologically-
based Levels
3
2
1
1
1
0
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
0
0
0
1
1
1
0
0
Page 8-15
-------
Exhibit 8-5 (continued)
Occurrence of Waste Constituents by Industry Group
Industry Group (SIC)
Stone, Clay, and Glass Products (32)
Fabricated Metal Products (34)
Constituent
Ammonia
Arsenic
Barium
Benzene
Beryllium
Cadmium
Calcium
Carbon disulfide
Chemical Oxygen Demand
Chloride*
Chromium
Cobalt
Conductivity
Copper*
Cyanide
Chemical Oxygen Demand
Chloride*
Chromium
cis-l,2-Dichloroethylene
Lead
Manganese*
Nitrate
PH*
Phenol
Total Dissolved Solids*
Trichloroethylene
Zinc*
Number of
Occurrences in
Release
Descriptions
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Number of
Occurrences
Above
Regulatory,
Health- or
Ecologically-
based Levels
1
1
1
1
1
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
1
1
1
1
0
1
1
Page 8-16
-------
Exhibit 8-5 (continued)
Occurrence of Waste Constituents by Industry Group
Industry Group (SIC)
Industrial Machinery and Equipment (35)
Apparel and Other Textile Products (23)
Instruments and Related Products (38)
'
Constituent
Arsenic
Cadmium
Chromium
Lead
PH'
Phenol
Zinc*
Cadmium
Nitrate
Total Organic Carbon
Grease and Oil
Phenol
Number of
Occurrences in
Release
Descriptions
1
1
1
1
1
1
1
1
1
1
1
1
Number of
Occurrences
Above
Regulatory,
Health- or
Ecologically-
based Levels
0
1
0
1
0
1
1
1
1
1
0
1
Constituents with Secondary Maximum Contaminant Levels.
organics for some of the industries could be slightly misleading. For example, a large number of
volatile organic chemicals were detected in the release descriptions from the chemicals and allied
products industry and petroleum refining, but each chemical was detected infrequently, so they do not
appear in Exhibit 8-5.
The persistent chlorinated pesticides were not among the most frequently detected chemicals,
except in two industries.. Pentachlorophenol was detected in a single release, description from the
primary metals industry. Semivolatile organics are likewise not among the most frequently detected
analytes in the release descriptions, but this may be a function of the poor mobility of many of these
chemicals in groundwater, rather than their lack of presence in the wastes. As was the case for the
volatile organics, a large number of pesticides and semivolatile organics were detected in the release
descriptions from the chemicals and allied products sector and each such chemical was found only one
or a few times.
The pattern of chemical detections and health-based or ecologically-based exceedences varied
widely among the industry groups, as discussed in Section 8.1.2. As noted previously, the frequency
of non-health-based and non-ecologically-based exceedences is relatively high among some industry
groups with the highest number of total chemicals detected. For example, SMCLs, which are based on
Page 8-17
-------
aesthetic considerations (e.g., water taste and odor), exist for 6 of the 15 most commonly detected
analytes for the refuse systems sector (SIC 4953) and the paper and allied products industry (SIC 26),
and 7 of the 15 analytes from the chemicals and allied products industry (SIC 28). Again, this finding
may be somewhat misleading because many of the less frequently detected analytes from these sectors
do have health-based or ecologically-based standards. Furthermore, some constituents with SMCLs
may also pose health and ecological risks. The same pattern applies to stone, clay, and gas products
(SIC 32), and food and kindred products (SIC 20). In the food and kindred products industry, the
only health-based exceedences were for nitrates, nitrites, or both. All of the other most frequent
exceedences for this industry group were non-health-based and non-ecologically-based.
8.2.4 Industries Reporting Releases of TC Analytes or Known or Possible Non-
Hazardous Industrial Waste Constituents
Another indication of the potential importance of the various industries with regard to non-
hazardous industrial waste management is provided by data concerning the amounts of chemicals these
industries release to the environment, as reported under the EPCRA TRI requirements. Exhibit 8-6
identifies, by industry, volumes of TC analytes or known or possible non-hazardous industrial waste
constituents that in 1992 were reported released to land or underground injection in an amount
exceeding 1 million pounds.7 Volumes of waste released to land or underground injection are
presented in this Study because they are thought to be the most indicative of the volume of non-
hazardous waste at the facilities. The listed volumes are the mass of individual constituents in waste
streams or other emissions rather than total waste volumes as presented in other exhibits in this
chapter. The volumes may include hazardous, special, and municipal solid waste as well as non-
hazardous industrial waste.
The largest volume of constituents reported released via underground injection in 1992 were
from the chemicals and allied products industry, which contributed 99.3 percent of total volume from
underground injection. A significant portion of these constituents may be in hazardous wastewaters.
The second and third largest volumes of TRI constituents come from the petroleum refining and
primary metals industries, which contributed 0.57 and 0.04 percent of total volume from underground
injection, respectively. The two constituents released in the largest volumes to underground injection
from the chemicals and allied products industry were methanol and acetonitrile, with 38 and 29
percent of total volume for that industry, respectively. Methanol was also released in the highest
volume from the petroleum refining industry, comprising 57 percent of the total constituent volume
reported for that industry.
The largest volume of constituents released to land originates from the primary metals
industry, which contributes 74.2 percent of the total volume. Most of that volume (99 percent) is
comprised of constituents, such as zinc, copper, and chromium, that may be present in large volume
special wastes. (Further investigation is needed to determine whether any of these releases involve
special or hazardous wastes.) The two chemicals comprising almost equal proportions released by this
industry are zinc and copper, with about 48 percent each. The second and third largest volumes of
constituents were from the petroleum refining and paper and allied products industries, respectively.
Petroleum refining contributed 10.1 percent of total volume and paper and allied products contributed
8.4 percent of total volume released to land. Naphthalene and xylene, with 43 and 32 percent of total
volume reported released to land, constituted the largest proportion of the constituents from the
7 Detailed 1994 TRI facility-specific data were not available when this Study was prepared, therefore, 1992 TRI
data were used.
Page 8-18
-------
EXHIBIT 8-6 THI REPORTED RELEASES TO LAND OR UNDERGROUND INJECTION BY CONSTITUENT AND INDUSTRY
ChemlcilNime*
1,1.1-THICHLOROETHANE
1,2-OICHLOROETHANE
1.3-BUTAOIENE
ACETALDEHYDE
ACETONITRILE
ACRYLAMIDE
ACRYLONITRILE
ANILINE
BENZENE
BROMOMETHANE
CARBON DISULFIDE
CHLOROBENZENE
CHLOROFORM
CHLOROMETHANE
CHLOROPRENE
CHROMIUM
COPPEH
CUMENE
DICHLORODIFLUOROMETHANE
DICHLOROMETHANE
ETHYLBENZENE
FORMALDEHYDE
FHEON113
METHANOL
METHYL ETHYL KETONE
METHYL ISOBUTYL KETONE
METHYL METHACRYLATE
N-BUTYL ALCOHOL
NAPHTHALENE
PROPYLENE OXIDE
STYRENE
TETRACHLOROETHYLENE
TOLUENE
TRICHLOROETHYLENE
TRICHLOROFLUOROMETHANE
VINYL CHLORIDE
XYLENE (MIXED ISOMERS)
ZINC (FUME OR DUST)
Total
Type of
Chemical
VCO
VCO
VO
OVO
OVO
OSO
OVO
OSO
VO
OVO
OVO
VCO
VCO
VCO
VCO
10
M/l
VH
VCO
VCO
VH
OVO
CFC
OVO
OVO
OVO
OVO
OVO
OSO
OVO
VH
VCO
VH
VCO
VCO
VCO
VH
M/l
SIC 20
Ul
5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
u
0
0
0
0
0
0
0
0
fa
L
25
1,000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2,100
0
200
0
20.250
0
0
0
0
0
0
0
0
0
0
0
0
0
250
23,625
SIC 21
Ul
0
0
0
0
0
0
0
0
0
0
0
0
.0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
0
0
0
6
SIC 22
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
12,482
0
0
0
0
0
0
0
0
0
0
0
0
0
5
12,487
SIC 24
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5
5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
11
L
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
250
0
0
0
0
10.139
0
17,495
250
0
0
0
1
0
0
0
434
0
0
0
0
5
28,574
SIC 25
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
5,800
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
250
0
0
80.327
27.931
139,400
0
8.856
0
0
0
0
65,114
0
0
0
44,914
0
372,592
SIC 26
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
0
0
0
0
0
0
30
0
0
0
0
0
11,582
0
0
0
0
0
0
251
0
4,336
0
2.957.167
6.873
0
11
0
8.445
0
5
0
798
0
0
0
250
1.100
2.990,848
SIC 27
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
975
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3.000
0
0
0
0
0
0
0
0
4,300
0
0
0
40
0
8.315
SIC 28
Ul
553
6.927
1.000
1,905.859
20,111.640
4.188.680
3.795.670
1.195,676
268,921
1,000
2.704
72.000
50,240
86,709
54.000
0
16.460
11.000
1.722
1,183.867
190.648
4.916.248
17
26.852,672
325.390
129.100
220.000
2.324,731
60.654
200
83.170
12.780
1.547.118
466
8
1
200,309
120.000
69,938,141
L
1.826
858
372
289
29
963
387
1.173
225,952
0
5
817
17.000
0
0
4.550
14,810
315
23
377
5,735
16.314
6
220.185
26.226
1,823
1.742
519
23,191
2,251
60,330
4.264
26.211
1
18.912
6
3,129
28.710
709,301
SIC 29
Ul
0
0
0
0
0
0
0
0
78.162
0
0
0
0
0
0
0
0
4.100
0
0
3.234
0
0
230,590
40.000
0
0
0
573
0
0
0
26,778
0
0
0
18.835
0
402.272
L
288
0
0
0
0
0
0
0
114,164
0
16
0
0
0
0
2,226
0
468
0
10
271,175
0
0
1,582
74£
35
0
C
1.539,299
C
C
0
546,483
0
0
0
1.142.430
C
3.618.924
SIC 30
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
C
0
0
0
G
C
(
(
t
0
0
0
0
t
(
0
0
0
0
(
C
t
5
L
17.403
0
0
0
0
0
7.654
0
0
0
0
0
0
0
1.811
2
0
0
0
46,620
0
0
0
0
10,770
0
2,250
0
0
0
141.15S
1.495
c
0
0
0
0
25C
229.412
SIC 31
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
e
0
0
0
0
0
C
0
0
0
0
0
0
(
(
L
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
7,707
C
C
0
0
0
0
0
0
0
0
0
0
0
0
(
0
0
0
0
3.100
0
(
10.807
Source: 1992 TRI data.
Ul = Underground Injection
L = Land
VCO » Volatile Chlorinated Organlcs
OVO * Other Volatile Organlcs
OSO = Other Semlvolatlle Organlcs
M/l = Metals/Inorganics
VH = Volatile Hydrocarbons
IO = Inorganics
VO Volatile Organlcs
CFC = Chtorolluorocarbons
Industry Groups (SIC)
20 = Food and Kindred Products
21 = Tobacco Products
22-Textile Mill Products
24 = Lumber and Wood Products
25 = Furniture and Fixtures
26 = Paper and Allied Products
27 = Printing and Publishing
281 = Chemicals and Allied Products
29 = Petroleum Refining
30 = Rubber and Miscellaneous Plastics Products
31 = Leather and Leather Products
32 = Stone, Clay and Glass Products
33 « Primary Metal Industries
34 = Fabricated Metal Products
35 = Industrial Machinery and Equipment
36 = Electronic and Other Electronic Equipment
37 = Transportation Equipment
38 = Instruments and Related Products
39 = Miscellaneous Manufacturing Products
Page 8-19
-------
EXHIBIT 8-6 TRI REPORTED RELEASES TO LAND OR UHDERQROUND INJECTION BY CONSTtTUEHT AND INDUSTRY (continued)
Ch*m!c«lN*mt'
1 ,1 ,1-TRlCHLOROETHANE
1,2-DICHLOROETHANE
1.3-BUTADIENE
ACETAtDEHYDE
ACETONITRILE
ACRYLAMIDE
ACRYLONITRILE
ANILINE
BENZENE
BROMOMETHANE
CARBON DISULFIDE
CHLOROBENZENE
CHLOROFORM
CHLOROMETHANE
CHLOROPRENE
CHROMIUM
COPPER
CUMENE
DICHLORODIFLUOROMETHANf
DICHLOROMETHANE
ETHYLBENZENE
FORMALDEHYDE
FREON113
METHANOL
METHYL ETHYL KETONE
METHYL ISOBUTYL KETONE
METHYL METHACRYLATE
M-BUTYL ALCOHOL
NAPHTHALENE
PROPYLENE OXIDE
STYRENE
TETHACHLOROETHYLENE
TOLUENE
TRICHLOROETHYLENE
TRICHLOROFLUOROMETHANE
VINYL CHLORIDE
XYLENE (MIXED ISOMERS)
ZINC (FUME OR DUST)
Total,
Typtol
Crwmtc*!
vco
vco
vo
ovo
ovo
oso
ovo
oso
vo
ovo
ovo
vco
vco
vco
vco
10
M/l
VH
vco
vco
VH
ovo
CFC
ovo
ovo
ovo
ovo
ovo
oso
ovo
VH
vco
VH
vco
vco
vco
VH
M/l
SIC 32
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
. 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
10.528
787
0
0
77
0
105.331
0
0
0
0
0
0
0
0
97,000
5
4.926
0
0
0
5
0
218.637
SIC 33
Ul
0
0
0
0
0
0
0
0
8.600
0
0
0
0
0
0
8
271
0
0
0
0
0
0
0
0
0
0
0
17.000
0
0
0
0
0
0
0
0
0
25.879
L
2.916
0
0
0
0
0
0
0
500
0
0
0
0
0
0
842.104
12,579,039
0
0
12,705
0
38.109
0
411
0
750
0
0
96,200
0
5
0
750
10.050
0
0
102,068
12,785.679
26,471,286
SIC 34
Ul
U
0
0
0
0
0
0
0
0
0
0
0
0
0
0
70
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
70
L
39,778
0
0
0
0
0
0
0
0
0
0
0
0
0
0
75,306
18,368
0
0
0
11,510
0
0
4.296
95.930
23.381
0
46,865
0
0
0
3.5B5
41.652
2.250
250
0
104,695
122,303
590,169
SIC 35
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
6,805
0
0
0
0
0
0
0
0
0
0
0
0
0
0
13,226
2,620
0
0
17,101
48
0
0
2.305
62,575
21,235
0
190
0
0
0
5
4.196
0
599
0
1.337
0
132,242
SIC 36
Ul
3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
197
169
5
0
0
0
0
0
0
0
5
0
0
0
120
0
499
L
10
0
0
0
0
0
0
0
0
0
0
0
0
0
0
500
25,709
0
0
12
0
0
850
0
0
0
0
0
0
0
0
0
5
0
0
0
4.350
0
31,436
SIC 37
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
250
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
250
L
200
0
0
0
0
0
0
0
20
0
0
0
0
0
0
455
5.130
0
0
0
0
0
250
9,041
8,291
8,291
0
0
0
0
5.686
0
8.944
8.420
0
0
10,961
102.816
168,505
SIC3B
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
350
0
0
0
0
0
0
0
0
0
0
0
0
0
0
510
0
0
0
60
0
0
7,922
0
1,500
0
0
0
0
0
0
0
0
5
0
0
0
10,347
SIC 39
Ul
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
645
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
250
0
0
0
250
1,145
Invalid
Ul
0
0
0
0
0
0
65,880
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
750
(
0
0
0
0
0
0
0
0
0
0
0
0
66.630
L
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
390
0
0
0
700
71
0
790
0
0
0
0
4.21C
0
0
0
10.600
c
16,766
Total Ul
561
6.927
1.000
1,905.859
20.111.640
4,188,680
3,861.550
1.195.676
355,683
1,000
2.704
72.000
50.240
86.709
54.000
333
16,736
15.100
1.722
1.183.867
193.882
4,916,248
214
27.084.182
365,395
129.100
220.000
2,324.731
78.227
200
83.170
12,780
1.573.901
466
(
1
219.270
120.000
70.433.762
Total Und
76581
1.658
372
289
29
963
8.071
1.173
340.636
0
21
817
28.582
0
1,811
957,112
12.647.33E
783
2!
79,31!
289.108
174.429
9,028
3.328.541
241. 79*
194.986
4.003
57.220
1.667.141
2,251
304.179
9,354
708,278
20.726
19.761
3.106
1.434.42!
13.041,123
35,655.029
Total
Combined
78542
8.785
1.372
1.906.148
20.111.669
4.189,643
3.669.621
1.196.849
696.319
1.000
2.725
72.817
76,822
86.709
55.611
957,445
12.664,074
15,88!
1.745
1,263.180
482,990
5.090.677
9,242
30.412.723
607.18!
324.086
224,003
2,381.951
1.745.368
2.451
387.349
22.134
2,282,179
21.192
19,769
3.107
1.653.699
13.161.123
106.088,791
Source:. 1992 TRI data.
Ul = Underground Injection
L = Land
VCO = Volatile Chlorinated Organlcs
OVO = Other Volatile Organlcs
OSO » Other Semlvolallle Organlcs
M/l = Metals/Inorganics
VH = Volatile Hydrocarbons
10 " Inorganics
VO = Volatile Organlcs
CFC = Chlorofluorocarbons
Industry Groups (SIC)
20 = Food and Kindred Products
21 = Tobacco Products
22 = Textile Mill Products
24 = Lumber and Wood Products
25 = Furniture and Fixtures
26 = Paper and Allied Products
27 = Printing and Publishing
28 = Chemicals and Allied Products
29 = Petroleum Refining
30 * Rubber and Miscellaneous Plastics Products
31 = Leather and Leather Products
32 «= Stone, Clay and Glass Products
33 = Primary Metal Industries
34 = Fabricated Matal Products
35 a Industrial Machinery and Equipment
36 = Electronic and Olher Electronic Equipment
37 = Transportation Equipment
38 = instruments and Related Products
39 = Miscellaneous Manufacturing Products
Page 8-20
-------
petroleum refining industry. Almost 99 percent of the volume of constituents released to land by the
paper and allied products industry was methanol.
8.3 Potential Gaps as a Function of Management Practices
This section of the Scoping Study reviews the available information related to management
practices:
Section 8.3.1 examines the prevalent management practices among the major
non-hazardous industrial waste generating industries;
Section 8.3.2 reviews the evidence regarding environmental releases as a function of
management type for major management technologies;
Section 8.3.3 describes limited data available on the potential hazards associated with
use constituting disposal; and
Section 8.3.4 briefly discusses the potential nature of the hazards associated with less
well-characterized management practices.
8.3.1 Waste Management Practices by Waste Type and Industry
As noted previously, the data related to non-hazardous industrial waste management practices
are quite limited and may be somewhat outdated. Inconsistencies frequently were found between data
from the different sources. Exhibit 8-7 summarizes the information for the relatively high volume
generation industries. Based on the available information, the vast majority of non-hazardous
industrial waste is aqueous and is managed in surface impoundments before treatment and ultimate
discharge under NPDES. The proportion of these wastes going to surface impoundments in 1985
ranged from 78.6 percent in the food and kindred products industry to 99.7 percent in the textile
manufacturing industry, with a total of 96.5 percent of all wastes managed in this fashion in the 15
industries included in the exhibit. The second most widely used land-based management technology
was land application. Only about 1.3 percent of the waste volume from the 15 industries was
managed in this fashion in 1985, with substantially larger proportions going this route in the organic
chemicals industry (3.1 percent), the food and kindred products industry (20 percent), and water
treatment industry (15 percent). Landfills and waste piles each accounted for about one percent of the
total waste managed in the 15 industries.
Exhibit 8-8 estimates the number of active landfills, surface impoundments, land application
units, and waste piles used to manage non-hazardous waste in various industry groups in 1985. At
that time, 55 percent of these land-based units were surface impoundments. This finding indicates
that, on average, surface impoundments handled larger volumes of waste than other management units
since they managed a substantially greater percentage (96 percent) of total on-site non-hazardous
industrial waste. In all industries except primary iron and steel and transportation equipment, surface
impoundments were the most common type of management units. Waste piles constituted 19 percent
of the total units. They were the most common type of unit in the primary iron and steel and
transportation equipment industries, were the second most common type in eight industries, and tied
for second in another. Land application units represented 16 percent of all units. Over 70 percent of
these units, however, were in the food and kindred products industry. Landfills represented only 10
percent of all units.
Page 8-21
-------
Exhibit 8-7
Volume of Non-Hazardous Industrial Waste Managed in Land-Based Facilities in 1985
Major Industry Group (SIC)
Paper and Allied Products (26)
Primary Metals Industry (33)b
Primary Iron and Steel (332)
Primary Non-ferrous Metals (333)
Chemicals and Allied Products (28)c
Industrial Inorganic Chemicals (281)
Plastics and Resins Manufacturing (282)
Fertilizer and Agricultural Chemicals (287)
Industrial Organic Chemicals (286)
Electric, Gas, and Sanitary Services (49)d
Electric Power Generation (4911)
Water Treatment (4941)
Stone, Clay, Glass, and Concrete (32)
Food and Kindred Products (20)
Textile Manufacturing (22)
Petroleum Refining (29)
Rubber and Misc. Products (30)
Transportation Equipment (37)
Leather and Leather Products (31)
Total
Treatment or Disposal Method
(percentages)3
Landfill
0.30%
0.39
0.3
2.1
0.74
0.4
0.05
3.5
0.4
4.7
4.9
0.3
1.2
1
0.03
0.2
2.2
1.4
0.3
1.10%
Surface
Impoundment
99.30%
98.5
99.2
84.3
95.3
95.1
98.2
93.1
96.3
94.5
95
84.5
97.3
78.6
99.7
99.6
97.4
93,1
99.4
96.50%
Land
Application
0.40%
0.04
<0.01
0.6
0.21
0.01
0.02
0.5
3.1
0.78
0.03
15
<0.01
20
0.3
0.2
0.2
<0.01
0
1.30%
Waste
Piles
0.07%
1.1
0.5
13
3.7
4.5
1.7
2.9
0.08
0.08
0.08
0.1
1-5
0.1
<0.01
0.05
0.2
4.6
0.3
1%
Total
Tons
Managed
(1000 tons/yr.)
2,251,700
1,367,611
1,300,541
67,070
1,324,722
919,725
180,510
165,623
58,864
1,151,123
1,092,277
58,846
621,974
373,517
253,780
168,632
24,198
12,669
3,234
7,621,147
Source: U.S. Environmental Protection Agency, "Report to Congress: Solid Waste Disposal in the United
States," Volume H, Table 3-5, October 1988.
a The entries in each column may not add to their respective totals because of rounding.
b The -Primary Metals Industry includes only SICs 332 (Primary Iron and Steel) and 333 (Primary
Non-ferrous Metals).
c Chemicals and Allied Products includes only SICs 281 (Industrial Inorganic Chemicals), 282 (Plastics
and Resins Manufacturing), 286 (Industrial Organic Chemicals), and 287 (Fertilizer and Agricultural
Chemicals).
d Electric, Gas, and Sanitary Services includes only 4911 (Electric Power Generation) and 4941 (Water
Treatment).
Page 8-22
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Exhibit 8-8
Active Non-Hazardous Industrial Waste Management Units in 1985 by Major Industry Group
Major Industry Group (SIC)
Food and Kindred Products (20)
Stone, Clay, Glass, and Concrete
Products (32)
Paper and Allied Products (26)
Electric Power Generation (4911)
Industrial Inorganic Chemicals
(2812-2819)
Petroleum Refining (29)
Primary Iron and Steel (3312-3321)
Water Treatment (4941)
Textile Manufacturing (22)
Primary Non-ferrous Metals
(3330-3399)
Transportation Equipment (37)
Fertilizer and Agricultural
Chemicals (2873-2879)
Rubber and Miscellaneous Products
(30)
Industrial Organic Chemicals (286)
Plastics and Resins Manufacturing
(2821)
Selected Chemicals and Allied
Products (28, except sectors
otherwise noted)
Leather and Leather Products (31)
Totala
Number of Treatment or Disposal Units
Landfill
194
1,257
259
155
120
61
201
121
28
111
63
31
77
17
32
21
9
2,757
Surface
Impoundment
4,166
3,152
918
1,220
1,039
915
383
659
741
448
287
274
176
262
292
219
102
15,253
Land
Application
3,128
309
139
43
24
114
76
147
72
9
11
160
16
27
17
17
0
4,308
Waste
Piles
540
2,528
232
110
98
158
464
48
103
312
362
50
123
79
32
41
54
5,335
Total
8,028
7,246
1,548
1,528
1,281
1,248
1,124
975
944
880
723
515
392
385
373
298
165
27,653
Source: Report to Congress, "Solid Waste Disposal in the United States," Volume n, EPA, Office of Solid
Waste and Emergency Response, October 1988.
a The entries in each column may not add to their respective totals because of rounding.
Page 8-23
-------
Surface impoundments, land application, landfills, and waste piles are clearly not the only
management technologies that can be used for non-hazardous industrial wastes" The totals in
Exhibit 8-7 do not reflect all of the possible options for waste management. Exhibit 8-9 provides data
from the Industrial D Industry Profiles discussed in Section 8.1 relating to non-hazardous industrial
waste management practices in some industries occurring most frequently in the release descriptions.
Most of these data are from the 1987 TSDR, and some are from the ISDB. Waste management
practices summarized in this source are substantially different from those shown previously. The data
are more detailed, and information is given for additional management methods, including
container/tank storage, wastewater treatment systems, underground injection, recycle/reuse, and
incineration.
The TSDR/ISDB data identify wastewater treatment systems (WWT and tank systems) as the
dominant management methods for most industries, instead of surface impoundments. This difference
may be partially due to the characterization of management units in the two surveys. Many of the
units identified as "impoundments" in the TSS may have been identified as "WWT units" in the TSDR
or ISDB. Also, the populations of facilities and wastes covered in the two surveys are different. For
example, the TSDR Survey covered facilities in a wide range of industries, but only if they managed
hazardous waste. The ISDB, on the other hand, covered a broader range of facilities, but only if they
were in certain industry groups. In any event, the two sources generally agree that land-based
treatment for aqueous wastes is the dominant management method for non-hazardous industrial wastes.
Land application, landfills, and waste piles show up as relatively minor management
technologies, by volume, in the TSDR/ISDB data, consistent with the TSS data. Underground
injection is also a minor but not insignificant management technology, accounting for up to
approximately three percent of total waste management in the industries where it is most widely used.
Some non-hazardous industrial wastes from all of the industries evaluated are recycled or reused (up to
about 1.5 percent). Incineration also accounted for less than one percent of all non-hazardous
industrial wastes managed in the various industries. The only waste management technology identified
as being important for any industry other than those mentioned is "other processes/methods," which
accounted for almost 50 percent of the wastes managed from the stone, clay, glass, and concrete
industry. The process used to manage these wastes was not indicated, but it may include use in
roadbed or fill.
8.3.2 Management Practices Seen in the Release Descriptions
The release descriptions for non-hazardous industrial waste management contain information
about the types of management units at which releases to the environment have occurred. This source
provides some direct evidence as to which types of management practices have the greatest potential
for causing releases to the environment. Its major limitations, however, are that it covers only
facilities for which data were readily available, namely regulated units, and that some of releases are
relatively old.
Page 8-24
-------
Exhibit 8-9
Non-Hazardous Industrial Waste Management by Industry
and Waste Type from TSDR and ISDB
Industry Group (SIC)
Chemicals and Allied
Products (280, 282
(except 2821), 285, 288,
289 (except 2891, 2892,
2893))
Industrial Inorganic
Chemicals (281)
Plastics and Resins
(2821)
Major Waste
Type(s)a'b
Aqueous Liquid
Organic Liquid
Aqueous Liquid
Solid Residue
Gas
Sludge/Slurry
Aqueous Liquid
Management Type(s)
WWT & Tank Systems0
Surface Impoundments0
Underground Injection0
Incineration0
Landfill0
Other Processes/Methods0
Recycle/Reuse0
Land Application15
WWT & Tank Systems0
Underground Injection0
Recycle/Reuse1*
Other Processes/Methods1*
Waste Pile Storage15
Surface Impoundments'5
Landfillb
Incineration0
WWT & Tank Systems0
Surface Impoundments0
Underground Injection15
Landfillb
Recycle/Reuse15
Land Application1*
Incineration15
Waste Pile Storageb
Other Processes/Methods15
Container/Tank Storage1*
Total
Amount
(thousand
metric tons)
79,669
2,029
236
43
14
8
4
<1
25,421
958
752
395
356
263
43
2
68,414
45,842
421
132
73
41
. 25
5
3
<1
Page 8-25
-------
Exhibit 8-9 (continued)
Non-Hazardous Industrial Waste Management by Industry
and Waste Type from TSDR and ISDB
Industry Group (SIC)
Drag and Medical
Products (283)
Industrial Organic
Chemicals (268)
Agricultural Chemicals
(287)
Major Waste
Type(s)a'b
Aqueous Liquid
Aqueous Liquid
Gas
Organic Liquid
Aqueous Liquid
Management Type(s)
WWT & Tank Systems0
Recycle/Reuse0
Surface Impoundments0
Underground Injection0
Incineration0
Landfill0
WWT & Tank Systems0
Surface Impoundments0
Recycle/Reuse15
Other Processes/Methods1*
Underground Injection13
Incineration1*
Landfillb
Land Application1*
Other Processes/Methods0
Container/Tank Storageb
Waste Pile Storage0
WWT & Tank Systems0
Surface Impoundments0
Underground Injection1*
Other Processes/Methods0
Incineration15
Landfill15
Land Application15
Container/Tank Storage1*
Recycle/Reuse1*
Waste Pile Storage15
Total
Amount
(thousand
metric tons)
197,143
1,818
193
126
18
<1
182,642
78,193
3,867
3,705
3,296
1,667
1,406
225
33
7
3
110,869
664
462
122
52
37
29
20
13
2
Page 8-26
-------
Exhibit 8-9 (continued)
Non-Hazardous Industrial Waste Management by Industry
and Waste Type from TSDR and ISDB
Industry Group (SIC)
Products of Petroleum
and Coal (29)
Stone, Clay, Glass, and
Concrete (32)
Steel Works, Blasting
(331)
Iron and Steel Foundries
(332)
Major Waste
Type(s)a'b
Aqueous Liquid
Sludge/Slurry
NA
Aqueous Liquid
NA
Management Type(s)
WWT & Tank Systems0
Land Application1*
Recycle/Reuse13
Underground Injectionb
Surface Impoundments0
Other Processes/Methods'5
Container/Tank Storageb
Landfill5
Incineration0
Waste Pile Storage0
WWT & Tank Systems0
Other Processes/Methods0
Surface Impoundments0
Recycle/Reuse0' d
WWT & Tank Systems0
Recycle/Reuse1*
Surface Impoundments0
Underground Injection1*
Other Processes/Methods15
Landfillb
Incineration
Container/Tank Storageb
Waste Pile Storage0
Surface Impoundments0
Waste Pile Storage0
Other Processes/Methods0
Total
Amount
(thousand
metric tons)
137,446
2,323
2,189
1,946
1,237
513
107
64
6
5
2,210
2,174
180
38
428,486
2,216
390
332
258
47
19
<1
<1
1,335
39
39
Page 8-27
-------
Exhibit 8-9 (continued)
Non-Hazardous Industrial Waste Management by Industry
and Waste Type from TSDR and ISDB
Industry Group (SIC)
Nonferrous Metals
Primary Smelting (333)
Fabricated Metal Products
(34)
Electronics & Other
Electronic Equipment
(36)
Major Waste
Type(s)a»b
NA
Aqueous Liquid
Sludge/Slurry
NA
Management Type(s)
WWT & Tank Systems0
Landfillc
Recycle/Reuse0
WWT & Tank Systems6
Surface Impoundments0
Other Processes/Methods0
Incineration0
Landfillb
Recycle/Reuse*1
Container/Tank Storage13
WWT & Tank Systems6
Surface Impoundments0
Recycle/Reuse0
Incineration0
Total
Amount
(thousand
metric tons)
6,656
24
<1
11349
668
15
4
2
<1
<1
21,463
,1,447
10
5
NA - No data available
a Includes waste types greater than 1% of total
bISDB
c TSDR; total does not include gases
^ Reuse of fuel only
Page 8-28
-------
Exhibit 8-10 tabulates by industry the number of waste management units of different types
found in the release descriptions. Of the 120 waste management units identified in the release
descriptions, 73 (61 percent) are landfills, while 28 (23 percent) are surface impoundments. Twelve
land application units (10 percent) and 4 waste piles were also identified, along with one trench,
1 evaporation pond, and 1 stormwater retention pond.
These data provide a somewhat different picture than would be expected, merely based on the
number of management units in the various industries and the volumes of wastes managed in different
types of units. Despite the preponderance of landfills in the release descriptions, the vast majority of
the non-hazardous industrial wastes are being managed (or were being managed at the time of the
TSS) in surface impoundments. As shown in Exhibit 8-8, for the industries presented, there are
15,253 surface impoundments versus only 2,757 landfills. Several possible explanations for this
apparent discrepancy can be advanced. First, better groundwater monitoring data may be available for
landfills than for surface impoundments. Second, management methods may have changed
substantially in the last 11 years. This explanation seems unlikely; surface impoundments or related
treatment systems probably will remain a management method of choice as long as aqueous wastes are
the dominant waste form. Some movement to tanks or other treatment systems may have occurred,
and process changes may also have reduced the volume of liquid wastes, but EPA has no information
as to how extensive these changes may have been. In any event, a large-scale shift away from surface
impoundments to landfills seems unlikely, simply based on cost considerations, even if it was
technically feasible for some wastes.
Another possible explanation is that the initial concentrations of potentially toxic constituents
may be lower, on average, for surface impoundments than for landfills, and the highly concentrated
solid residues from the impoundments may themselves end up in landfills, or the surface
impoundments may be closed as landfills. Finally, design features of non-hazardous industrial waste
landfills may make them more prone to releases, although the other factors just discussed are likely to
be more important.
8.3.3 Potential Hazards Associated with Use Constituting Disposal
Few data are available on use that constitutes disposal (UCD) of solid wastes, which is
regulated at the state level. Some data, however, are available for one category of these wastes:
certain delisted wastes that are now being used in a manner constituting disposal. In the first case
discussed below, a full risk assessment of UCD was not done at the time the waste was delisted. In
the second case, pending proposals at the federal level would authorize UCD of delisted wastes; some
states, however, may already be permitting some UCD practices for these wastes under other
regulatory provisions.
Delisted K088 (spent potliners from primary aluminum reduction) that has been treated with
lime and heated in a rotary kiln by a specific petitioner and subsequently disposed of primarily in a
monofill has caused high leaching rates of cyanides, fluoride, and arsenic. While the treatment residue
passes the TCLP test, the leachate from the monofill exceeds the TC level for arsenic and the delisting
requirements for cyanides and fluoride. The treatment residual also has a pH of approximately 12.9
and is hazardous and not covered by the petitioner's exclusion. This K088 treatment residual also has
been used for on-site road construction, under a state RCRA Subtitle D management permit. A recent
site inspection found, after rainfall, large puddles of dark colored water, the same color as the
treatment residue used to build the road. Samples of the runoff water are currently being analyzed.
Page 8-29
-------
Exhibit 8-10
Waste Management Unit Types in the Release Descriptions3
Industry Group
Agricultural Production-Livestock (02)
Apparel and Other Textile Products (23)
Chemicals and Allied Products (28)
Electric, Gas, Sanitary Services (49)
Electronic and Other Electronic Equipment (36)
Fabricated Metal Products (34)
Food and Kindred Products (20)
Industrial Machinery and Equipment (35)
Instruments and Related Products (38)
Nonmetallic Minerals, Except Fuels (14)
Paper and Allied Products (26)
Petroleum Refining (29)
Primary Metal Industries (33)
Stone, Clay, and Glass Products (32)
Transportation Equipment (37)
Total Units
Evaporation
Pond
1
1
Lagoon/
Surface
Impoundment
1
6
2
1
6
1
1
5
2
1
1
1
28
Land
Application
I
1
7
1
1
1
12
Landfill
5
33
1
2
3
23
1
2
1
2
73
Stormvvater
Retention
Pond
1
1
Trench
1
1
Waste
Pile
I
3
4
Total
2
1
11
35
2
4
13
1
1
4
29
4
7
2
4
120
1A facility may have more than one waste management unit.
Page 8-30
-------
This case raises two issues:
The appropriateness of the TCLP test for evaluating the leaching potential of
this waste treatment residual.
The potential unevaluated risks from runoff from this material when used in a
manner constituting disposal.
The first issue is discussed in Section 3.6. With respect to the second issue, EPA will evaluate the
runoff risks from this site and potentially risks from other instances where states have permitted uses
constituting disposal for non-hazardous industrial waste.
Risks from some UCD practices for some delisted wastes may not be fully understood.
Comments on UCD proposals to allow several uses of high temperature metals recovery (HTMR) slags
derived from K061, K062, and F006 listed wastes expressed concern about the completeness of risk
evaluation. The proposed rule8 would allow the de-listed HTMR slags to be used in road building as
top grade material, as aggregate in cement, and as anti-skid material. EPA evaluated the risk from
these materials using the TCLP test to estimate potential for leaching to groundwater. Commentors,
however, expressed concerns about risks from surface runoff and wind-blown dust pathways and risks
to workers. At the time of the proposal in December 1994, models to evaluate non-groundwater
pathway risks were not adequately developed. Since then, such models have been developed and were
used in a major rulemaking proposal, the December 1995 HWIR-Waste proposal. These models are
undergoing revision in response to comments by the public and the Science Advisory Board (SAB).
The modeling developed to support HWIR-Waste could be used to evaluate UCD of de-listed HTMR
slags or other stabilized waste once the models are refined.
8.3.4 Potential Hazards Associated with Other Management Practices
As noted in Section 8.3.1, it is clear that some non-hazardous industrial wastes are being
managed in ways that do not involve treatment or final disposal in land-based units such as surface
impoundments or landfills. These other management approaches may also pose potential risks to
human health and the environment. In the course of the Scoping Study, the Agency has found little
recent, reliable information as to the types and volumes of non-hazardous industrial wastes being
managed using other technologies. A major complication in this regard is that, unlike the situation for
hazardous wastes, generators are not required by federal regulations to identify or report non-hazardous
industrial wastes, process residuals, or byproducts. Thus, any residual or byproduct material that has
potential economic value does not need to be identified as a waste, and instead may simply be used or
sold without restriction. In such cases, the distinction between what constitutes the simple commercial
sale of a material that happens to be a byproduct of an industrial process, recycling, or use constituting
disposal of a non-hazardous industrial waste may not be clear.
Putting this problem aside, it is certain that some non-hazardous wastes are being managed
using techniques other than land storage, treatment, or disposal. Some of these technologies, such as
incineration, unambiguously involve releases to the environment. Others such as recycling and reuse
may involve releases, depending upon the nature of the use of the materials. In EPA's search for
release descriptions, no instances were found where any of these alternative management methods had
859 Federal Register 67256, December 29, 1994.
Page 8-31
-------
resulted in documented environmental releases meeting the stringent release selection criteria. In
addition, as noted previously, the state non-hazardous industrial waste programs that constitute the
major source of the release descriptions may not regulate some of these alternative waste management
technologies. Thus, the available data do not allow a conclusion to be drawn about whether and to
what extent such management methods may pose significant risks to human health or the environment.
This data gap is discussed in more detail in Chapter 10.
Page 8-32
-------
CHAPTER 9. POTENTIAL FOR GAPS TO BE ADDRESSED
BY EXISTING REGULATIONS
The potential gaps described in Chapters 3 and 4 of this Scoping Study were identified solely
in terms of their relationship to non-hazardous industrial waste management, and not with regard to
whether they might be controlled under RCRA or other regulatory programs. This chapter examines
the extent to which existing regulatory programs may already address these potential gaps and thereby
helps to evaluate the extent of the potential gaps. The programs reviewed are as follows:
RCRA,
Clean Water Act (CWA),
Safe Drinking Water Act (SDWA),
Clean Air Act (CAA),
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA),
Toxic Substances Control Act (TSCA),
Pollution prevention initiatives,
Occupational Safety and Health Act (OSHA), and
Hazardous Materials Transportation Act (HMTA).
The regulatory control provided by these programs is reviewed in general terms, rather than in detail.
Further analysis would be necessary to determine the precise degree of protection that these programs
provide against particular risks.
9.1 RCRA Programs
Where there are gaps in the hazardous waste characteristics, the RCRA hazardous waste
listings and Subtitle D program may reduce any resulting human health and environmental risks.
These two programs are discussed below, including both the direct federal regulatory authorities and
state-delegated authorities.
9.1.1 Hazardous Waste Programs
As described in RCRA Section 3001(a)-(b), EPA is required to develop regulations that both
specify criteria for listing hazardous waste and to list particular hazardous wastes. In 40 CFR 261.11,
EPA has specified three criteria for listing solid wastes as hazardous:
The waste exhibits a hazardous characteristic;
The waste is acutely hazardous because is has been found to be fatal to
humans in low doses, or is otherwise capable of causing or significantly
contributing to an increase in serious irreversible, or incapacitating reversible,
illness; or
Page 9-1
-------
The waste contains a toxic constituent listed in 40 CFR Part 261, Appendix
Vin1 and, after considering several risk-based and non risk-based factors, is
capable of posing a substantial present or potential hazard to human health or
the environment when improperly treated, stored, transported, or disposed of,
or otherwise managed.
EPA has established four hazardous waste lists:
Hazardous waste from non-specific sources, or F wastes;
Hazardous wastes from specific sources, or K wastes;
Discarded commercial chemicals that are toxic, or P wastes; and
« Discarded commercial chemicals that are acutely hazardous, or U wastes.
Because the F and K listings focus on waste streams, rather than on particular constituents,
identification of a chemical as a constituent in a listed F or K waste does not automatically imply that
all or most industrial wastes containing that constituent are regulated by the hazardous waste listings.
For example, the F003 listing regulates benzene when it is a spent solvent, but does not regulate other
benzene-containing wastes such as petroleum refining wastes. Similarly, for .a chemical to be
controlled by a P or U listing, it must be a discarded commercial product. If the source of the
chemical is different (e.g., from a waste mixture that is not covered by an F or K listing), it is not
regulated as a listed waste. For example, 2,4-dimethylphenol, which is a listed U waste (U101) when
it is a discarded commercial chemical, was found among the environmental releases from non-
hazardous industrial waste management documented in Chapter 2. This chemical also was found in
the other two sources of data on non-hazardous industrial waste constituents, the Industrial Studies
Database (ISDB) and the Effluent Guidelines Development Documents.
40 CFR Part 261, Appendix YE contains the majority of the "known" non-hazardous industrial
waste constituents, including:
40 of the 41 known non-hazardous industrial waste constituents found in all
three major data sources: the release descriptions, ISDB, and the effluent
guideline development documents data; and
134 of all 248 known constituents.
Although Appendix VII constituents are the basis for individual hazardous waste listings, they also
appear in non-hazardous industrial wastes. The listings, therefore, do not regulate all wastes
containing these constituents.
Most states have developed their own hazardous waste programs and have received EPA
approval to implement their regulations in lieu of the federal program. These state hazardous waste
regulations may be broader or more stringent than federal RCRA Subtitle C regulations. A number of
states have done so by regulating additional wastes as hazardous. For example, states have:
Expanded the ignitability, corrosivity, or reactivity (ICR) characteristics;
Expanded the toxicity characteristic (TC);
1 Constituents are included in Appendix VXQ if a reputable scientific study has found that the constituent has
toxic, carcinogenic, mutagenic, or teratogenic effects on humans or other forms of life.
Page 9-2
-------
Listed wastes as hazardous that are not hazardous under the federal rules; and
Restricted exemptions from the federal program.
These expansions beyond the federal hazardous waste identification rules, which are discussed in
Chapter 6, reflect state judgments about gaps in the federal program and thereby fill these potential
gaps in particular states. Conversely, these expansions constitute potential gaps in other states.
9.1.2 Subtitle D
States have primary responsibility for managing non-hazardous industrial wastes. Under
RCRA Subtitle D, the Federal Government only establishes minimum criteria that prescribe the best
practicable controls and monitoring requirements for non-hazardous waste disposal facilities. EPA has
developed separate criteria for municipal solid waste landfills (MSWLFs), which must comply with the
requirements of 40 CFR Part 258, and for non-hazardous industrial (Industrial D) land application
units, which must comply with the requirements of 40 CFR Part 257.
40 CFR Part 258 specifies six categories of MSWLF criteria: location, operation, design,
ground-water monitoring and corrective action, closure and post-closure care, and financial assurance.
Most relevant to addressing potential gaps in the characteristics, any leachate from new MSWLFs
(which began accepting waste after October 9, 1993) must not cause contaminant levels in the
uppermost aquifer to exceed maximum contaminant levels (MCLs) specified under the Safe Drinking
Water Act. In addition, all MSWLFs must be operated in a way that ensures that they do not release
pollutants that violate the Clean Water Act. Beyond meeting the minimum federal criteria, approved
States are permitted to develop their own standards for MSWLFs.
The operating and design requirements for MSWLFs under Part 258 are designed to allow
protective disposal of conditionally exempt small quantity generator hazardous waste (CESQG). As a
result, MSWLFs can accept non-hazardous and CESQG waste from both municipal and industrial
sources. Industrial D landfills can accept conditionally exempt small quantity generator (CESQG)
waste (e.g., construction and demolition waste) only if they meet the location, groundwater monitoring
and corrective action requirements specified in 40 CFR Part 257. Industrial D landfills that do not
meet these requirements are not permitted to accept CESQG waste.
To a limited extent, state non-hazardous industrial waste management programs address
potential gaps in the hazardous waste characteristics. These state programs, however, vary
considerably in the types of requirements imposed, the stringency of such requirements, and even the
types of waste management units regulated. They do not provide uniform national coverage of
non-hazardous industrial waste management. For example, despite the state requirements placed on
these landfills, about 50 chemicals were found in the release descriptions at concentrations above
MCLs, including a number of metals (e.g., zinc, nickel, mercury, and lead) and volatile chlorinated
organics (e.g., vinyl chloride, carbon tetrachloride, chlorobenzene, and chloroform). Similarly, about
90 percent of all releases were found to be associated with unlined management units; not all states
currently require Industrial D units to be lined.
92 Medium-Specific Regulations
Medium-specific regulations such as the Clean Water Act, the Safe Drinking Water Act, and
the Clean Air Act can both directly and indirectly address potential gaps in the hazardous waste
characteristics. These programs regulate exposure via specific pathways of potential concern for non-
Page 9-3
-------
hazardous industrial wastes, as discussed in Chapters 3 and 4. Medium-specific regulations also could
indirectly address potential gaps by discouraging or preventing the occurrence'of the specific
constituents in non-hazardous industrial waste. For example, CWA regulations may cause a
manufacturer to alter a production process so that a particular chemical that requires control is not
used in the production process, thereby eliminating that constituent from its solid waste stream. Where
substitutions or alterations in the production process are not feasible, however, the medium-specific
regulations could result in cross medium transfers, increasing the use of solid waste disposal as the
preferred management method of the regulated constituents. The net effect of these two incentives on
solid waste disposal practices is uncertain.
9.2.1 Clean Water Act
The CWA is designed to restore and protect the physical, chemical, and biological quality of
the nation's surface waters. To achieve this goal, all discharges to navigable waters must be permitted.
To help permit writers, EPA has established effluent limitations for 127 toxic pollutants on direct
discharges to waters by 34 industrial source categories and publicly-owned treatment works (POTWs).
Permit writers use these guidelines to establish discharge limits and other permit conditions. Where
effluent guidelines do not exist for an industry, permit writers use best engineering judgment to
determine appropriate permit conditions,
CWA regulations and permits directly limit exposures through surface water pathways. The
CWA also indirectly addresses exposures to CWA regulated chemicals though other pathways by
providing incentives for reducing or eliminating the use of such chemicals or for cross-media transfer
of such chemicals.
Chapter 3 identified three potential gaps in the current toxicity characteristic that may be
addressed to some extent by the Clean Water Act:
Potential risks from direct surface water exposures;
Potential indirect pathway risks involving surface waters; and
Potential risks to ecological receptors involving surface waters.
As discussed in Chapter 3, surface water exposure pathways may be significant for some TC
analytes disposed as non-hazardous industrial waste. Because run-off waters from landfills must be
managed according to the requirements of the CWA, risks to human health from surface water
exposures are addressed if these TC analytes have effluent limits established under the CWA. These
effluent limits may also address risks to ecological receptors from exposure surface water, principally
at water bodies near waste management units contaminated from surface water run-off. In addition,
persistent and bioaccumulative chemicals discharged to surface waters may contaminate fish and
shellfish that, when consumed, cause indirect exposure risk to human health. CWA effluent limits can
address indirect exposure risks from those TC analytes for which effluent limits are established.
As Exhibit 9-1 demonstrates, CWA effluent limits are established for 28 of the TC
constituents, including all of the TC metals except barium. Many of these TC constituents are
commonly found in the release descriptions. For example, 7 of the top 20 frequently occurring
constituents in the release descriptions are TC metals. Other TC constituents occurring five or more
times in the release descriptions that have CWA effluent limits include benzene, vinyl chloride,
chloroform, chlorobenzene, and tetrachloroethylene. Among these constituents, chlorobenzene,
mercury, and lead can pose risks to ecological receptors.
Page 9-4
-------
Exhibit 9-1
TC Constituents with Effluent Limits Established under CWA
CWA
Effluent
TC Analyte Limit
1 , 1 -Dichloroethylene
,1,2-Dichloroethane S
1,4-Dichlorobenzene S
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol J
2,4-D, salts and esters
2,4-Dinitrotoluene S
Arsenic S
Barium
Benzene S
Cadmium S
Carbon tetrachloride J
Chlordane S
Chlorobenzene S
CWA
Effluent
TC Analyte Limit
Chloroform S
Chromium S
Cresol (mixed isomers)
Endrin /
Heptachlor S
Heptachlor epoxide S
Hexachlorobenzene S
Hexachloro- 1,3-butadiene
Hexachloroethane S
Lead S
Lindane S
m-Cresol
Mercury S
Methoxychlor
CWA
Effluent
TC Analyte Limit
Methyl ethyl ketone
Nitrobenzene J
o-Cresol
p-Cresol
Pentachlorophenol S
Pyridine
Selenium S
Silver , /"
Silvex (2,4,5-TP)
Tetrachloroethylene S
Toxaphene S
Trichloroethylene S
Vinyl chloride S
The CWA effluent limitations may also address some of the potential gaps identified in
Chapter 4 that are associated with non-TC constituents, including indirect pathway exposures to
phenolic compounds, DNAPL formation by chlorinated organics, indirect pathway exposure to PAHs,
and indirect pathway exposure to phthalate esters. For the CWA to address indirect pathway
exposures to these chemicals, releases to surface water from regulated facilities must be involved.
Exhibit 9-2 lists chemicals representative of these potential gaps and indicates which chemicals are
subject to CWA effluent limitations. Effluent limitations are specified for 7 of the 8 and for 15 of the
18 phenols and PAHs, respectively, on the list of known non-hazardous industrial waste constituents.
CWA effluent limitations also control surface water releases of the chemicals that are likely to form
DNAPLs, including halogenated chemicals. Exhibit 9-2 lists 35 known non-hazardous volatile
chlorinated organics. Of these chemicals, 18 are subject to effluent guideline limits. CWA effluent
limitations are specified for all six of the phthalate esters on the list of known non-hazardous industrial
waste constituents. Phthalate esters are one class of chemical that bioaccumulate in the environment
and may be endocrine disrupters.
Page 9-5
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Exhibit 9-2
CWA Effluent Limitations Relevant to Certain Known Non-Hazardous Industrial Waste
Constituents
Phenols
CWA
Effluent
Limit
Volatile Chlorinated Organics
(Potential DNAPL formers)
CWA
I Effluent
! Limit
PAHs
CWA
Effluent
Limit
2,4-Dimethylphenol
2,4-Dinitrophenol
2-Nitrophenol
4,6-Dinitro-o-cresol
4-Nitrophenol
p-Chloro-m-cresol
Phenol
Phenolics
^
S
S
1,1,1,2-Tetrachloroethane
1,1,1-Trichloroethane /
1,1,2,2-Tetrachloroethane S
1,1,2-Trichloroethane S
1,2,3-Trichloropropane
1,2,4,5-Tetrachlorobenzene -
1,2,4-Trichlorobenzene S
l,2-Dibromo-3-chloropropane
1,2-Dichlorobenzene S
1,2-Dichloroethylene
1,2-Dichloroethylene, trans S
1,2-Dichloropropane /
1,3-Dichlorobenzene /
1,3-Bichloropropylene S
Allyl chloride
Benzole trichloride .
Bis(2-chloroethyl) ether /
Chlorobromomethane
Chlorodibromomethane /"
Chloroethane /
Chloromethane
-------
Exhibit 9-3
CWA Coverage of Industries Represented in Release Descriptions
Industry Group
Electric, Gas, and Sanitary
Services (refuse only)
Paper and Allied Products
Chemicals and Allied
Products
Food and Kindred Products
Primary Metals
Non-Metallic Minerals
SIC Code
49
26
28
20
33
14
Total Number
of Releases
35
27
11
10
6
4
CWA Effluent Limitations
no
yes
yes; separates organic and inorganic
manufacturing
no
yes; separates nonferrous and iron/steel
manufacturing
no
9.2.2 Safe Drinking Water Act
Under the Safe Drinking Water Act, EPA has identified contaminants in drinking water that
may adversely affect human health. For each contaminant, EPA has established a maximum
contaminant level (MCL) that must not be exceeded in drinking water. MCLs are based on maximum
contaminant level goals (MCLGs), which are the non-enforceable health-based levels at which no
known or anticipated adverse effects on the health of people occur and which allow an adequate
margin of safety. MCLGs are adjusted to MCLs based on considerations of feasibility, including
technical implementation and economic considerations. As discussed in Section 5.1, EPA also has
established non-health based or non-ecological based drinking water standards, based principally on
aesthetic or usability criteria, which are called Secondary MCLs (SMCLs).
The MCL standards apply to public water systems that regularly supply water to 15 or more
connections or to 25 or more individuals at least 60 days per year in the case of residential populations
or at least 6 months per year in the case of non-residential populations. The SDWA also regulates,
through EPA or approved state programs, the underground injection of wastes to protect aquifers that
are or may reasonably be expected to be sources of drinking water. These aquifers must be protected
from contamination that violates an MCL or otherwise adversely affect human health.
The SDWA has become important beyond the regulation of public water systems and
underground injection of waste because the MCLs have been used in other regulatory contexts. For
example, RCRA Subtitle D regulations for municipal solid waste landfills specify that MCLs must not
be exceeded in the uppermost aquifer underlying a landfill.
Because the regulatory levels established under the SDWA apply only to public water systems,
its ability to address potential gaps resulting from non-hazardous industrial waste management is
limited. The 1996 Safe Drinking Water Act (SDWA) Amendments, however, establish a new
emphasis on preventing contamination problems through source water protection. Within 18 months
after EPA publishes guidance, states must submit a program for delineating source water areas of
public water systems and for assessing the susceptibility of such source waters to contamination.
Because SDWA MCLs have been established for a number for TC and non-TC constituents that are
related to potential gaps, the SDWA could be used under such source water protection programs to
Page 9-7
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regulate contaminants prior to their entry into public water systems, such as at non-hazardous
industrial waste management units. The constituents and possible gaps that the SDWA could address
under source water protection programs are discussed below. At this point in time, however, no such
source protection programs have been developed.
In Chapter 3, groundwater risks associated with TC analytes were identified as a potential gap
in the hazardous characteristics. As Exhibit 9-4 shows, MCLs are established for 27 of the TC
constituents, including all TC metals with the exception of silver. The seven TC metals with
established MCLs are among the top 20 frequently occurring constituents in the release descriptions.
MCLs are also established for other constituents frequently occurring in the release descriptions
including chlorobenzene, chloroform, tetrachloroethylene, trichloroethylene, and vinyl chloride. The
MCLs for chlorobenzene, lead, and mercury may address the ecological risks posed by these
constituents, even though EPA did not specifically evaluate ecological risks when setting the MCLs.
Exhibit 9-4
TC Constituents with SDWA MCL Levels
j SDWA
TC Analyte | MCL
1,1-Dichloroethylene
1,2-Dichloroethane S
1,4-Dichlorobenzene J
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2,4-D, salts and esters S
2,4-Dinitrotoluene
Arsenic J
Barium S
Benzene S
Cadmium S
Carbon Tetrachloride S
Chlordane S
Chlorobenzene /
j SDWA
TC Analyte \ MCL
Chloroform ~ S
Chromium S
Cresol (mixed isomers)
Endrin S
Heptachlor J
Heptachlor epoxide J
Hexachlorobenzene J
Hexachloro-l,3-butadiene .
Hexachloroethane
Lead /"
Lindane S
m-Cresol
Mercury J
Methoxychlor J
\ SDWA
TC Analyte | MCL
Methyl ethyl ketone
Nitrobenzene
o-Cresol
p-Cresol
Pentachlorophenol J
Pyridine
Selenium S
Silver
Silvex (2,4,5-TP) S
Tetrachloroethylene J
Toxaphene J
Trichloroethylene J
Vinyl chloride J
Chapter 4 identified two groups of known non-hazardous industrial waste constituents that may
present hazards through the groundwater pathway: toxic metals and volatile chlorinated organic
compounds. Exhibit 9-5 lists chemicals representative of these gaps and indicates whether they have
MCLs and were detected above MCL levels in the release descriptions presented in Chapter 2. In the
release descriptions, most of these constituents were detected in groundwater at levels above their
MCLs.
Page 9-8
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Exhibit 9-5
MCLs for Known Non-Hazardous Industrial Waste Constituents of Concern
in Groundwater Pathways
Metals
Aluminum (fume or dust)
Antimony
Beryllium
Chromium(VI)
Cobalt
Copper
Iron
Magnesium
Manganese
Molybdenum
Nickel
Strontium
Thallium
Tin
Titanium
Vanadium
Zinc
MCL
/
/
-
~
/
/"
-
Detected
above MCL
/
/
-
'
~
/
/
-
Volatile Chlorinated Organics
1,1,1 ,2-Tetrachloroethane
1,1,1 -Trichloroethane
1 , 1 ,2,2-Tetrachloroethane
1 , 1 ,2-Trichloroethane
1 ,2,3-Trichloropropane
1 ,2,4,5-Tetrachlorobenzene
1 ,2,4-Trichlorobenzene
1 ,2-Dibromo-3-chloropropane
1 ,2-Dichlorobenzene
1 ,2-Dichloroethylene
1,2-Dichloroethylene, trans
1 ,2-Dichloropropane
1 ,3-DicWorobenzene
1 ,3-Dichloropropylene
Allyl chloride
Benzoic trichloride
Bis(2-chloroethyl) ether
Chlorobromomethane
Chlorodibromomethane
Chloroethane
Chloromethane
cis- 1,2-Dichloroethylene
Dichloro-2-propanol 1,3-
Dichlorobromomethane
Dichlorodifluoromethane
Dichloromethane
Dichloropropane
Epichlorohydrin
Ethylidene Dichloride
Hexachlorocyclopentadiene
Pentachloroethane
Tetrachloroethane, N.O.S.
trans-1 ,3-Dichloropropene
Trichlorofluoromethane
Trichloromethanethiol
MCL
..
/
/
-
/
/
/
S
s
--
/
/
^
/
/
-
/
~
~
Detected
above MCL
..
/
^
^
/
-
-
.
Page 9-9
-------
9.2.3 Clean Air Act Amendments
Section 112 of the Clean Air Act Amendments (CAAA) regulates emissions of 189 toxic
constituents, or hazardous air pollutants (HAPs). EPA has defined source categories that emit these
HAPs and specified the maximum available control technology (MACT) that must be used by these
sources to reduce HAP releases. EPA has promulgated air toxics regulations for three source
categories that handle solid waste: RCRA Subtitle C facilities, off-site waste operations, and
municipal waste combustors. Of these three categories, only off-site waste operations handle non-
hazardous industrial waste.
Off-site waste operations are defined to include hazardous waste treatment, storage, and
disposal facilities, industrial wastewater treatment facilities, industrial waste landfills that receive waste
from off-site, and other facilities that provide waste management support services or recover and/or
recycle spent materials. Municipal waste landfills, POTWs, incinerator units, and site remediation
activities are not regulated by this rule. Off-site operations must control emissions from tanks and
containers that manage material with an average volatile organic compound (VOC) concentration equal
to or greater than 100 parts per million by weight. Land disposal of such wastes is prohibited. In
addition, a leak detection and repair program must be implemented for all equipment containing
material with total VOC concentration of 10 percent or more. Thus, the CAA regulations for these
sources could address potential gaps in the hazardous waste characteristics in two ways:
Exposures to waste constituents through inhalation are addressed for
non-hazardous industrial wastes with average VOC content greater than 100
ppm, if managed in certain facilities; and
Exposure to VOCs at off-site operations through direct contact with solid
waste or from groundwater leachate may be reduced or controlled by the
prohibition of land disposal of wastes that contain material with an average
VOC concentration equal to or greater than 100 parts per million by weight.
The CAA has the potential to address inhalation exposures from the TC constituents. As
Exhibit 9-6 demonstrates, all but seven TC constituents (counting heptachlor expoxide) are designated '
as HAPs under the CAA.
Inhalation pathway exposure to non-TC volatile chlorinated organic compounds and to
persistent organic pesticides were identified in Chapter 4 as a potential gap in the hazardous waste
characteristics. As- Exhibit 9-7 demonstrates, the CAA regulates emissions of 16 of the 35 known non-
hazardous volatile chlorinated organics. EPA also has designated as HAPs two of the six persistent
pesticides identified in the second column of Exhibit 4-11.
Like the CWA, the CAA specifies emission limits for selected industries. Thus, for a potential
gap to be addressed by the CAA, the gap constituents must be generated by one of the industrial
categories regulated by the CAA. Exhibit 9-8 demonstrates that little overlap exists between the
industries subject to CAA air toxics emission limits and those industries represented in the release
descriptions. Among the industries represented in the release descriptions, the CAA specifies emission
limits for segments of the chemicals production industry and off-site waste management operations.
Page 9-10
-------
Exhibit 9-6
TC Constituents Designated as HAPs under CAA
CAA
TC Analyte HAP
1,1-Dichloroethylene
1,2-Dichloroethane J
1,4-Dichlorobenzene J
2,4,5-Trichlorophenol J
2,4,6-Trichlorophenol J
2,4-D, salts and esters J
2,4-Dinitrotoluene J
Arsenic J
Barium
Benzene J
Cadmium J
Carbon tetrachloride J
Chlordane J
Chlorobenzene J
CAA
TC Analyte HAP
Chloroform S
Chromium J
Cresol (mixed isomers) /
Endrin
Heptachlor J
Heptachlor epoxide
Hexachlorobenzene /
Hexachloro-l,3-butadiene J
Hexachloroethane S
Lead J
Lindane J
m-Cresol f
Mercury f
Methoxychlor J
CAA
TC Analyte HAP
Methyl ethyl ketone J
Nitrobenzene J
o-Cresol J
p-Cresol S
Pentachlorophenol J
Pyridine
Selenium J
Silver
Silvex (2,4,5-TP)
Tetrachloroethylene J
Toxaphene J
Trichloroethylene J
Vinyl chloride J
-------
Exhibit 9-7
CAA Hazardous Air Pollutants (HAPs) Specified for Potential Gap Constituents
Volatile Chlorinated Organics ] CAA HAP
Persistent Organic Pesticides J CAA HAP
1,1,1,2-Tetrachloroethane
1,1,1-Tiichloroethane
1,1,2,2-Tetrachloroethane
1,1,2-Trichloroethane
1,2,3-Trichloropropane
1,2,4,5-Tetrachlorobenzene
1,2,4-Trichlorobenzene
l,2-Dibromo-3-cWoropropane
1,2-Dichlorobenzene
1,2-DicMoroethylene
1,2-DicWoroethylene, trans
1,2-Dichloropropane
1,3-Dichlorobenzene
1,3-Dichloropropylene
Allyl cWoride
Benzoic trichloride
Bis(2-chloroethyl) ether
Chlorobromomethane
Chlorodibromomethane
Chloroethane
Chloromethane
cis-1 ,2-Dichloroethylene
DichIoro-2-propanol, 1,3-
Dichlorobromomethane
Dichlorodifluoromethane
Dichloromethane
Dichloropropane
Epichlorohydrin
Ethylidene Bichloride
Hexachlorocyclopentadiene
Pentachloroethane
Tetrachloroethane, N.O.S.
trans-l,3-Dichloropropene
Trichlorofluoromethane
Trichloromethanethiol
Aldrin
DDD
DDE
DDT
Dieldrin
Hexachlorobenzene
S
S
s
s
s
s
s
Emissions standards have not yet been established for the paper, food, primary metals, or non-metallic
minerals industries. As presented in Exhibit 9-8, however, the most important industry in terms of the
potential gaps that the CAA may address is the organic chemicals manufacturing industry. Emissions
standards have been established for segments of this industry.
Page 9-12
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Exhibit 9-8
CAA Coverage of Industries Represented in Release Descriptions
Industry Group
Electric, Gas, and Sanitary
Services (refuse only)
Paper and Allied Products
Chemicals and Allied
Products
Food and Kindred Products
Primary Metals
Non-Metallic Minerals
SIC Code
49
26
28
20
33
14
Number of
Documented
Releases
35
27
11
10
6
4
CAA Air Emission Limits
Off-site waste operations, hazardous waste
TSDFs
no
Emissions from synthetic organic chemical
industry, elastomer production,
epichlorohydrin production
no
no
no
9.3 Federal Insecticide, Fungicide, and Rodenticide Act
FIFRA controls chemical pesticides through a process whereby the manufacturer registers the
composition of the pesticide and certifies to EPA that the pesticide will perform its intended function
without unreasonable adverse impacts in the environment under commonly recognized practices for
use. EPA can place a registered substance under special review if the substance is suspected of
causing unreasonable adverse effects on the environment. Under this process, EPA can prohibit the
distribution, sale, and/or use of a pesticide through a cancellation or suspension of its registration.
Four TC constituents found in the release descriptions are FIFRA active ingredients: 2,4-
D, heptachlor, methoxychlor, and pentachlorophenol. Because FIFRA only places conditions on use,
and does not set concentration-based regulatory levels or regulate pesticide waste disposal, the
regulation of these constituents by FBFRA does not automatically imply that releases will not exceed a
certain level. FIFRA could only prevent releases of these constituents if EPA were to cancel or
suspend the respective registrations.
Exhibit 9-9 lists the pesticides, intermediates, and degradation products that are TC analytes or
known non-hazardous industrial waste constituents and the current status of the pesticide. Of the 41
pesticides and associated products that are known non-hazardous industrial waste constituents, 25 are
currently in use and 16 are cancelled or are not currently used. Several of these pesticides passed the
multiple toxicity, persistence, volatility, and bioaccumulation screening criteria presented in
Exhibit 4-13, including aldrin, DDT, DDD, DDE, dieldrin, heptachlor epoxide, and hexachlorobenzene.
With the exception of heptachlor epoxide, these pesticides have been canceled by EPA, The presense
of many of these canceled pesticides as known non-hazardous industrial waste may largely be the
result of old data. For example, the release descriptions, which were used to identify known
constituents, cover waste management units that may have received wastes more than a decade ago.
Page 9-13
-------
Exhibit 9-9
Status of Pesticides That are TC Analytes
or Known Non-Hazardous Industrial Waste Constituents
Pesticides/Intermediate/Degradation Product
Status
Aldicarb
Atrazine
Carbofuran
2,4-D, salts and esters
Diazinon
Dimethoate
Disulfoton
Endosulfan (pesticide is a mixture of alpha and beta isomers)
Endosulfan, alpha-
Endosulfan, beta-
Endosulfan sulfate
Endothall
Heptachlor
Heptachlor epoxide
Lindane (gamma-HCH)
Molinate
Mesitylene
Methyl iodide
Methoxychlor
Methyl parathion
O,O-Diethyl O-pyrazinyl phosphorothioate (Thionazin)
Parathion
Pentachlorophenol
Phorate
Sulfotepp
Active; restricted use
Active; restricted use
Active; restricted use
Active
Active
Active
Active; restricted use
Active
Active
Active
Metabolic product of endosulfan
Active
Active; restricted use
Degradation product of heptachlor
Active; restricted use
Active
Active use (registration not required)
Active use (registration not'required)
Active
Active; restricted use
Active
Active; restricted use
Active; restricted use
Active; restricted use
Active
2,3,4,6-Tetrachlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Aldrin
alpha-HCH
beta-HCH
DDE
DDT/DDD
Dieldrin
Endrin
Endrin aldehyde
Endrin ketone
Famphur
Hexachlorobenzene
Silvex (2,4,5-TP)
Toxaphene
Canceled
Canceled
Canceled
Canceled
Canceled
Canceled; no longer produced in U.S.
Degradation product of canceled ingredient
Canceled
Canceled
Canceled
Byproduct/degradation product of endrin
Byproduct/degradation product of endrin
Most uses canceled; no currently active products
Canceled
Canceled
Most uses canceled; no currently active products
Sources: Farm Chemicals Handbook '94, Meister Publishing Company; U.S. EPA/OPP Database of Pesticide Products,
October 8, 1996, http://vwvw.cdpr.ca.gov/docs/epa/epamenu.htm; Status of Pesticides in Registration and Special
Review (Rainbow Report), Office of Pesticides and Prevention, U.S. EPA, June 1994; Merck Index. 12th edition,
1996.
Page 9-14
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9.4 Toxic Substance Control Act
TSCA was enacted to fill gaps in the Federal Government's authority to regulate problem
chemicals. Most EPA regulations, such as the Clean Air Act and the Clean Water Act, regulate
chemicals only after they are produced and used. However, there are many opportunities for a
chemical to cause harm to human health or the environment prior to it becoming a waste, such as
during production or use. Under Section 6 of TSCA, EPA has the authority to regulate the production,
use, distribution, and disposal of chemicals that are identified as potentially hazardous. EPA has
exercised the authority under Section 6 to regulate the production, distribution, and disposal of PCBs
from electrical equipment and as byproducts of chemical manufacturing processes. The presence of
PCBs in the release descriptions probably results from the past disposal of old products containing
PCBs. Because TSCA bans the production of PCBs, however, their presence in waste should diminish
over time. Actions under TSCA do not significantly address any other potential gaps.
9.5 Pollution Prevention
EPA has developed a number of pollution prevention initiatives that could address potential
gaps in the characteristics by limiting the production of harmful chemicals. These initiatives include:
Source Reduction Review Project (SRRP). EPA has an on-going effort to
introduce source reduction concepts into individual rules. As part of the
SRRP, EPA conducted an in-depth analysis of source reduction measures and
cross-media issues in the development of 24 rule makings for air toxics
(Maximum Achievable Control Technology or MACT standards), water
pollution (effluent guidelines) and hazardous wastes (listing determinations)
that were pending in 1993 and 1994. The project's goal is to foster the use of
source reduction measures as the preferred approach for achieving
environmental protection, followed in descending order by recycling, treatment,
and as a last resort, disposal. For the long term, EPA hopes that SRRP will
provide a model for the regulatory development efforts in all of its programs.
Environmental Technical Initiative (ETT). EPA has promoted pollution
prevention efforts for selected industries through technology development. For
example, the Agency has supported research on recycling plastics, replacing
current solvents with less harmful alternatives, and developing cleaner ,
processes in plating and metal finishing.
Waste Exchanges. Waste exchanges provide a mechanism for recycling and
reusing industrial waste. In general, waste exchanges try to match generators of
waste with companies interested in recycling or reusing these materials. The
goals of waste exchanges are to reduce disposal costs, reduce disposal
quantities, reduce demand for natural resources, and potentially increase the
value of wastes. EPA has supported the non-federal waste exchanges through
(1) funding a national computerized listing system, the National Materials
Exchange Network (NMEN), and (2) issuing grants to develop support for
individual waste exchanges or specific waste exchange activities.
Toxics Release Inventory (TRI). The TRI can have an instrumental role in
pollution prevention by providing communities with the information that can
Page 9-15
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be used to persuade industries to reduce emissions, and by establishing a
benchmark to measure progress. For example, EPA established the 33/50
Program whereby companies voluntarily pledged to reduce releases of 17
priority pollutants reported in TRI in 1988 by 33 percent in 1992 and by 50
percent in 1995.
Further research is needed to determine the impact of these initiatives on potential gaps in the
characteristics.
9.6 Occupational Safety and Health Act
Workplace safety is largely regulated by the Occupational Safety and Health Act (OSHA).
The program that most directly relates to chemical hazards encountered in the workplace is the
permissible exposure limits (PELs)2 established for selected workplace chemicals.
Subpart Z of 29 CFR 1910.1000 specifies PELs for toxic and hazardous substances in the
workplace. These PELs are based on threshold limits values (TLVs) established by the American
Conference of Governmental Industrial Hygienists (ACGIH) and on the Recommended Exposure
Limits (RELs) developed by the National Institute for Occupation Safety and Health (NIOSH). OSHA
has adjusted some of these values when developing PELs. The PELs are intended to reduce diseases
such as liver and kidney pains, neuropathy and cardiovascular effects, respiratory effects, deterioration
of lung function, narcosis, biochemical and metabolic changes, and other health impairments caused by
workplace exposure to chemicals.
As discussed above, OSHA regulates workplace inhalation exposure to designated constituents
by establishing PELs. As shown in Exhibit 9-10, 33, or over 75 percent, of the TC constituents have
PELs established under OSHA.
The majority of potential gaps associated with non-TC analytes identified in Chapter 4 are
related to exposures to contaminated media, rather than workplace exposures. OSHA PELs, however,
could address workplace exposures to a few of the major chemicals classes that comprise several of
the potential gaps, including volatile chlorinated organics, other volatile and semivolatile organics, and
pesticides. Exhibit 9-11 demonstrates that 21 of the 35 known non-hazardous volatile chlorinated
organics in Exhibit 4-2 have OSHA PELs. Similarly, 33 of the 41 and 20 of the 45 other volatile and
semivolatile organics, respectively, have OSHA PELs.
9.7 Hazardous Materials Transportation Act
HMTA gives th& Department of Transportation (DOT) the authority to regulate the
transportation of hazardous materials in interstate commerce. The HMTA regulates materials not
covered by the hazardous waste characteristic, and therefore addresses hazards from these potential
gaps, but only in the context of risks in transportation and to transportation workers. These materials
include the following:
2 A PEL is the average maximum concentration of a chemical in air that is allowable for a worker to be exposed
to in the course of an 8-hour working day.
Page 9-16
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Exhibit 9-10
TC Constituents with Established OSHA PELs
OSHA
TC Analyte PEL
1,1-Dichloroethylene
1,2-Dichloroethane J
1,4-Dichlorobenzene J
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2,4-D, salts and esters , ,/
2,4-Dinitrotoluene /
Arsenic J
Barium S
Benzene J
Cadmium /
Carbon Tetrachloride S
Chlordane S
Chlorobenzene J
OSHA
TC Analyte PEL
Chloroform S
Chromium S
Cresol (mixed /
isomers)
Endrin /
Heptachlor J
Heptachlor Epoxide
Hexachlorobenzene
Hexachloro- 1,3- S
butadiene
Hexachloroethane J
Lead /"
Lindane S
m-Cresol
Mercury S
Methoxychlor J
OSHA
TC Analyte PEL
Methyl ethyl ketone J
Nitrobenzene J
o-Cresol
p-Cresol S
Pentachlorophenol J
Pyridine J
Selenium S
Silver J
Silvex (2,4,5-TP)
Tetrachloroethylene J
Toxaphene J
Trichloroethylene J
Vinyl Chloride J
Page 9-17
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Exhibit 9-11
OSHA PELs Specified for Known Non-Hazardous Industrial Waste Constituents
Volatile Chlorinated ]
Organics j PEL
Other Volatile
Organics
PEL
Other Semivolatile j
Organics j PEL
1,1,1,2-Tetrachloroethane
1,1,1-Trichloroethane
1,1,2,2-Tetrachloroethane
1,1,2-Trichloroethane
1,2,3-Trichloropropane
1,2,4,5-Tetrachlorobenzene
1,2,4-Trichlorobenzene
l,2-Dibromo-3-chloropropane
1,2-Dichlorobenzene
1,2-Dichloroethylene
1,2-Dichloroethylene, trans
1,2-Dichloropropane
1,3-Dichlorobenzene
1,3-Dichloropropylene
Allyl chloride
Benzoic trichloride
Bis(2-chloroethyl) ether
Chlorobromomethane
Chlorodibromomethane
Chloroethane
Chloromethane
cis-l,2-Dichloroethylene
Dichloro-2-propanol, 1,3-
Dichlorobromomethane
Dichlorodifluoromethane
Dichloromethane
Dichloropropane
Epichlorohydrin
Ethylidene Dichloride
Hexachlorocyclopentadiene
Pentachloroethane
Tetrachloroethane, N.O.S.
trans-l,3-Dichloropropene
Trichlorofluoromethane
Trichloromethanethiol
1,2-Dibromoethane /
1,4-Dioxane S
2-Ethoxyethanol /"
2-Hexanone /
2-Methyllactonitrile
2-Methylpyridine
2-Nitropropane /
Acetaldehyde S
Acetone /"
Acetonitrile S
Acrolein /
Acrylonitrile S
Allyl alcohol /
Benzenethiol S
Benzyl alcohol
Bromoform S
Bromomethane «/
Carbon disulfide /
Crotonaldehyde
Cyclohexanone S
Dimethyl sulfate /
Dimethylamine /
Ethane, l,l'-oxybis- /
Ethyl acetate ' /
Ethylene glycol /"
Ethylene oxide S
Formaldehyde . S
Furan
Furfural S
Hydrazine /
Isobutyl alcohol S
Malononitrile
Methanol /
Methyl isobutyl ketone S
Methyl isocyanate S
Methyl mercaptan /
Methyl methacrylate /
Methylene bromide
n-Butyl alcohol /
Urethane
Vinyl acetate /
1,2-Diphenylhydrazine
2,3,7,8-TCDD
2,4-Diaminotoluene
2,4-Dichlorophenol
2,6-Dinitrotoluene
3,3'-Dimethoxybenzidine
4-Aminobiphenyl
4-Aminopyridine
5-Nitro-o-toluidine
Acetophenone
Acrylamide
Acrylic acid
Adipic acid
Aniline
Benzal chloride
Benzoic acid
Benzyl chloride
Biphenyl
Coal tars
Creosote
Dibenzofuran
Diphenyl ether
Diphenylamine
Ethyl dipropylthiocarbamate
Formic acid
m-Dinitrobenzene
Maleic anhydride
Maleic hydrazide
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
Naphthalene
Nitrosamine, N.O.S.
O-Chlorotoluene
Ortho(2-)Nitroaniline
p-Chloroaniline
p-Chlorotoluene
p-Nitroaniline
Pentachlorobenzene
Phenanthrene
Phthalic acid
Phthalic anhydride
Polychlorinated biphenyls
Resorcinol
Thioacetamide
Thiram
Page 9-18
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Combustible liquids defined under HMTA as liquids with a flash point above
141 F and below 200 F. Examples include berizonitrile, camphor oil,
chlordane, coal tar distillate, di-isobutyl ketone, ethylene glycol ethers, and fuel
oil distillate;
Corrosive solids and liquids;
aqueous flammable liquids (alcohol solutions < 24 percent);
Non-flammable compressed gases and cryogenic liquids; and
Certain materials specifically forbidden under HMTA, including materials likely to
polymerize at a temperature of 130 F or less, or decompose at 122 F or less, with an
evolution of a dangerous amount of heat or gas.
9.8 Summary
Most of the potential gaps identified in Chapters 3 and 4 are media-specific. As a result,
media-specific regulations provide some control over chemical and chemical classes that comprise the
potential gaps. In addition, non-media-specific regulations such as FIFRA and TSCA could address
potential gaps associated with particular chemical classes, such as pesticides and PCBs. Exhibit 9-12
presents a summary of the non-RCRA statutes and regulatory programs that could address to varying
degrees the potential gaps.
Exhibit 9-12
Potential Gaps and Potential Non-RCRA Regulatory Control
Statute or Regulatory
Program
Clean Water Act
Safe Drinking Water Act
Clean Air Act
FIFRA
TSCA
OSHA
HMTA
Potential Gap Possibly Addressed
Direct surface water exposure to TC analytes
Indirect pathway exposures to TC analytes involving surface waters
Risks to ecological receptors involving discharges to surface waters
Indirect pathway exposures to phenolic compounds involving surface waters
DNAPL formulation by chlorinated organics
Indirect pathway exposures to PAHs involving surface waters
Implementation of 1996 Amendments to CWA has potential to address
potential gaps through groundwater exposures to TC constituents, non-TC
metals, and non-TC volatile chlorinated organics
Inhalation pathway exposures to volatile chlorinated organics
Inhalation pathway exposures to persistent organic pesticides
Endocrine disruption from chlorinated pesticides, phthalate esters
Risks to humans, ecological receptors from PCBs
Inhalation exposures to TC analytes in workplace
Risks posed by gaps in the ICR characteristics
Page 9-19
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For a potential gap to be addressed by the CWA or CAA, the gap constituents must both have
regulatory levels established by the programs and be generated by one of the regulated industrial
categories. The CWA and CAA establish limits for about the same number of volatile chlorinated
organics. The industrial categories regulated by the CWA, however, overlap more extensively than
those regulated by the CAA with the industries represented in the release descriptions. Therefore the
CWA effluent limitations will be more effective in addressing potential gaps. Each of the regulations
discussed in this chapter do not address all of the known and possible non-hazardous industrial waste
chemicals, and therefore none of the potential gaps are completely addressed by non-RCRA
regulations.
Page 9-20
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CHAPTER 10. SUMMARY EVALUATION OF NATURE AND
EXTENT OF POTENTIAL GAPS
This chapter evaluates potential gaps in terms of their significance to human health and the
environment. It synthesizes and summarizes information presented in previous chapters.
Section 10.1 discusses the objectives of the gaps analysis and the specific criteria used to
evaluate potential gaps.
Section 10.2 presents the findings of the evaluation and discusses major data gaps and
unresolved issues.
Section 10.3 describes a possible framework for determining an appropriate course of action
based on the results of this Scoping Study.
10.1 Overview of the Evaluation of Potential Gaps
10.1.1 Objectives of the Gaps Analysis
Since this Study is a scoping exercise, the human health and environmental impacts of
potential gaps have not been definitively analyzed, and potential gaps are not numerically ranked with
regard to their impacts. Instead, the Study's objective is to summarize available information in a
manner that will be useful in guiding further, more detailed assessment of the most important potential
gaps and their possible solutions. The categories of gaps are evaluated qualitatively against criteria
that address the potential for adverse human health and environmental impacts.
Many of these criteria have been used in previous chapters to identify and analyze potential
gaps. The analysis presented below, however, differs from previous analyses in two ways. First,
while the same data sources are used, more detailed analyses are presented for key constituents,
pathways, and risks. Second, instead of focusing on individual chemicals, the chapter analyzes groups
of chemicals and specific environmental problems. This approach helps to generalize the analysis to
include chemicals for which limited data are available regarding appearance in wastes, toxicity, or
environmental fate and transport characteristics.
10.1.2 Criteria Used for Evaluating Gaps
Section 10.2 presents a series of exhibits (Exhibits 10-1 through 10-4) comparing the various
categories of potential gaps identified and reviewed in previous chapters. Potential gaps are compared
using criteria that relate to various dimensions of risks to human health and the environment. These
criteria, which correspond to columns in the exhibits, are described below. (Because of data gaps or
the inapplicability of some criteria to certain potential gaps, some exhibits do not include all of these
criteria.)
Nature of Risks. This criterion qualitatively characterizes the nature of the risks posed by
potential gaps, including the types of possible injuries or adverse effects, important lexicological
effects (e.g., carcinogenicity, reproductive effects, or mutagenicity), and fate and transport properties.
These factors are important in evaluating risk potential.
Page 10-1
-------
Presence in Non-Hazardous Industrial Waste. This entry indicates the number of the TC
analytes and known or possible non-hazardous industrial waste constituents identified in. Chapter 4 that
fall into the potential gap and summarizes other available data on presence in waste. The number of
chemicals in a given class indicates, to some extent, the potential frequency of their appearance in
non-hazardous industrial wastes or use in different industries.
Frequently Detected Constituents in Release Descriptions. This column indicates how
frequently the class of chemicals was detected in the documented releases from non-hazardous
industrial waste management facilities. These data provide a second indicator of the frequency of the
class of chemicals in wastes released to the environment. In some tables, this column also addresses
the extent to which the releases had constituent concentrations detected in excess of health- or
ecologically-based regulatory standards or other health-based levels. These data address the severity
and type of the risk presented by the releases.
TRI Chemicals with Releases > One Million Pounds. This column identifies any constituents
falling into the identified potential gaps that have 1994 TRI releases to air, land, water, and
underground injection combined greater than one million pounds. Eighty-three of the 250 individual
or classes of TRI chemicals for which data were available had reported releases exceeding one million
pounds. These data served as a proxy for widespread use and appearance in wastes.
Affected Industries. This column presents two types of data. First, it identifies the industries
most often associated with documented releases of a particular class of chemicals in the release
descriptions. These data indicate, at least for the population of facilities evaluated, which industries
seem to have the highest frequency of releases to the environment of each class of compounds. As
noted previously, however, this indicator is imperfect, in part because the available data focus on
releases to groundwater and some families of constituents may present risks primarily through other
pathways. The column also uses information presented in Chapter 8 to identify the industries with
particular classes of chemicals frequently occurring in their non-hazardous industrial wastes.
Affected Management Methods. This column identifies the types of management units at
which the various classes of chemicals are detected most frequently in the release descriptions or other
data sources. This criterion has the same limitation as the release description information identified
above, namely, it focuses on groundwater contamination and thereby may miss chemicals that pose
risks through other pathways. However, since presence in groundwater indicates presence in wastes,
this column also provides information about the types of management units or practices that have
releases to groundwater and are likely to have releases to other media (e.g., volatilization), as
discussed in the screening-level risk results from Section 3.5.
Potential Coverage by Other Regulations. This column summarizes information presented in
Chapter 5 (for large-scale environmental problems) and Chapter 9 (for TC and non-TC chemicals). It
briefly describes the potential extent of coverage of potential gaps by existing regulatory programs. In
some cases, despite the appearance that a particular gap is covered by a regulatory program,
information from the release descriptions or elsewhere may indicate that such coverage is not
preventing releases to the environment.
Comments/Data Gaps. The final column of each table identifies the major analytical
uncertainties and limitations in the characterization of potential hazardous waste characteristics gaps.
As noted above, a major obstacle to identifying gaps accurately and reliably is the shortage of
information regarding the generation, composition, and management of non-hazardous industrial wastes
Page 10-2
-------
and any human health or environmental damages resulting from the management of such wastes. Data
may be available to fill some of the identified gaps, but, due to time constraints, these data were not
used in preparing this Scoping Study.
10.2 Findings of the Evaluation
This section summarizes the evaluations of the five different types of potential gaps identified
in the previous chapters, namely potential gaps associated with:
The existing ignitability, corrosivity, and reactivity characteristics;
The existing toxicity characteristic;
Chemicals not included in the toxicity characteristic;
Natural resource damages and large-scale environmental problems; and
State expansion of the TC and listings.
The last part of this section reviews the major data gaps and uncertainties.
10.2.1 Potential Gaps Associated with the ICR Characteristics
Ignitability
Exhibit 10-1 summarizes the analysis of the potential gaps in the ICR characteristics. (This
exhibit does not include a column on the constituents that were frequently detected in the release
descriptions because of the difficulty of judging waste ICR properties based on the environmental
monitoring data (e.g., groundwater sampling from the release descriptions). The first page of the
exhibit addresses the limitations in the ignitability characteristic. The first potential gap in this
characteristic relates to the lack of coverage of combustible liquids, that is, liquids with flash points
above 140°F and below 200°F. The Agency has not found any data on how often non-hazardous
industrial wastes exhibit this property. While many non-hazardous industrial waste constituents are
flammable, the flash point and fire hazard from a given waste depends on its composition and
management practices. Thus, the high frequency of appearance of flammable liquids among the waste
constituents or groundwater contaminants does not necessarily reflect a high hazard potential. The
release descriptions did not allow EPA to evaluate the frequency of fires and explosions at non-
hazardous industrial waste management facilities, let alone to determine whether any fires had resulted
from combustible liquids.
Dilute aqueous solutions of alcohol also are identified as a potential gap in the ignitability
characteristic. These solutions might flash, even if they are not capable of sustaining combustion.
Ethanol, however, is not a known or possible non-hazardous industrial waste constituent or a TC
analyte, suggesting that this gap may not be significant. Nevertheless, the narrow definition of this
characteristic excludes other organic liquids that can form potentially flammable mixtures with water.
The possible limitations of this narrow definition are illustrated by the presence among waste
constituents of water-miscible alcohols, such as methanol (with the highest release volume on the TRI
list), n-butanol, and isobutanol, as well as other potentially flammable water-miscible solvents, such as
acetone, methylethyl ketone, and acetonitrile.
EPA found no data on the extent of potential hazards from ignitable solids. Thus, the
consequences of not having a test method for these materials are difficult to characterize. The release
Page 10-3
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Exhibit 10-1
Evaluation of Potential Gaps Associated With the Ignitability, Corrosivity, and Reactivity (ICR) Characteristics
Potential Gap
IGN1TABILITV
Exclusion of DOT
Combustible
Liquids (flash point
between !40"Fand
200°F)
Exclusion of
Aqueous Flam-
mable Liquids
(alcohol solutions <
24 percent)
References Out-
dated DOT Regula-
tions
No Ignitability
Test Method for
Non-liquids
Nature of Risk
Fires under plausible
mismanagement
scenarios
These liquids could
flash, even if combus-
tion is not sustained.
Confusion regarding
definition and test
methods due to incor-
rect DOT citation
More difficult to
interpret, comply with,
and enforce regula-
tions.
Presence In Non-
Hazardous Industrial
Waste
Some proportion of
wastcslrcams arc likely
to be combustible, but
are not readily identifi-
able with existing data.
Combustible materials
include certain alcohols,
low molecular weight
ethers, kerosene, jet
fuels, petroleum
byproducts, tints and
paints, and others.
Many constituents
could form flammable
mixtures with water.
Not applicable
Could include soils and
sorbents contaminated
with ignitable materials
TRI Chemicals with
1994 Reported
Releases > One
Million Ibs.
N-bulyl alcohol,
MIBK, ncctonitrilc,
cthylene glycol,
acelaldehydc
Mcthanol, n-butanol,
iso-bulanol, ethylene
glycol, acetonitrile,
MIBK, acetaldehyde
Not applicable
Not addressed
Affected Industries
Wide range of indus-
tries produce
combustible materials
including chemicals,
petroleum refining,
asphalt materials and
paving
Industries using
paints, adhcsives, inks,
and fuels
Chemicals, refuse
services
Not applicable
Not addressed
Affected Management
Methods
Hazards may be most
relevant for waste
handling activities such
as generation, storage.
and transportation.
Landfills more likely to
be of potential concern
than surface
impoundments because
surface impoundments
dilute wastes and thereby
reduce ignitability; flam-
mable organic liquids are
not likely to be managed
in impoundments.
Potential Coverage by
Other Regulations
Variety of local, state,
and federal laws address
ignilablc hazards, includ-
ing
- DOT transportation
rules;
Fire codes;
Emergency preven-
tion and preparedness
under EPCRA. OSHA,
andCAA§l!2(r);and
~ State Industrial D
rules limiting landfilling
of liquids.
Comments/Major Data
Gaps
Flash point of waste
depends on various
factors including concen-
trations of constituents.
Difficult to identify
potentially affected
wastestreams in the
absence of flash point
data for specific
wastestreams
No data available on
fires from combustible
liquids
DOT has a similar
exclusion.
No data available on
fires from these liquids
No data available on
fires due to improper
testing or failures to test
Potential gap is diffi-
cult to characterize.
DOT and NFPA have
defined test methods for
flammable solids.
Page 10-4
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Exhibit 10-1 (continued)
Evaluation of Potential Gaps Associated With the Ignitability, Corrosivity, and Reactivity (ICR) Characteristics
Potential Gap
CORROSIVITY
Exclusion of
Corrosive Non-
liquids
pH Limits Poten-
tially Not Protec-
tive, pH Test
Methods Not Pre-
dictive of Risk
Corrosion of Non-
Steel Materials Not
Addressed
Solubilizalion of
Non-Metals Not
Addressed
* Exclusion of
Irritants and
Sensitizers
Nature of Risk
Skin, eye injuries
and ecological risks,
facilitated transport of
pollutants
pH lest may not
identify some
corrosive materials
Corrosion of plastic,
clay, other liner
materials and non-
steel containers or
tanks
Organic solvents
may solubilize organic
constituents
Allergic reaction in
waste management
and transportation
workers
Unclear whether this
hazard meets RCRA
Subtitle C statutory
level of concern
Presence in Non-
Hazardous Industrial
Waste
Not addressed
Not addressed
Many NAPL-formers;
alcohols, ketones
Many potential LNAPL
or DNAPL forming
constituents could
solubilize other organics.
Numerous chemicals
including ammonia,
beryllium, cobalt, copper,
nickel, carbonyl,
formaldehyde, isobutyl
alcohol, n-Dioctyl
phlhalale, benzole acid,
and coal tars
TRI Chemicals with
1994 Reported
Releases > One
Million Ibs.
Not addressed
Not addressed
Toluene, xylene,
carbon disulfide,
styrene, ethylbeneze,
trichlorofluoromethane,
phenols (as group),
various alcohols
Toluene, xylene,
carbon disulfide,
styrene, ethylbeneze,
trichlorofluoromethane,
phenols (as group)
Ammonia,
formaldehyde, copper,
(of those listed in prior
column)
Affected Industries
Not addressed
-
Affected Management
Methods
Not addressed
Not addressed
Waste management
methods that involve
materials such as plastic,
clay, and other materials
besides steel
Waste management
methods with potential
for discharge to water
bodies or other habitats
Waste handling situa-
tions where spills could
occur
Potential Coverage by
Other Regulations
Several slates regulate
corrosive solids as
hazardous waste.
DOT and OSHA rules
use a dermal corrosion
test (not pH); they cover
worker and
transportation risks.
CAA limits disposal of
solvents in certain units.
CAA limits disposal of
solvents in certain units.
OSHA hazard
communication standard
covers irritants and
sensitizers, which affords
protection to employees
at wide range of
facilities (e.g., generating
facilities, waste
management facilities)
Comments/Major Data
Gaps
Lack of data on
specific substances,
wastes, and/or damage
cases that fall within
potential gaps.
Page 10-5
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Exhibit 10-1 (continued)
Evaluation of Potential Gaps Associated With the Ignitability, Corrosivity, and Reactivity (ICR) Characteristics
Potential Gap
REACTIVITY
Broad, Non-
Spccific Definition
References Out-
dated DOT Regula-
tions
No Test Methods
Specified
Nature of Risk
Ambiguity may
allow substances
posing risks of gas
generation or violent
reaction to be man-
aged improperly.
Confusion about
relevant standards
may reduce compli-
ance and increase
risks of violent reac-
tions.
More difficult to
interpret, comply with,
and enforce regula-
tions
Presence In Non-
Hazardous Industrial
Waste
Many constituents are
DOt-reaclive, none ore
identified as "highly
reactive".
TRI Chemicals with
1994 Reported
Releases > One
Million Ibs.
Ammonia,
hydrochloric acid,
phosphoric acid, nitric
acid, sulfuric acid,
hydrogen fluoride,
hydrogen cyanide,
chlorine dioxide
Affected Industries
Not addressed
Affected Management
Methods
Not addressed
Potential Coverage by
Other Regulations
Explosions and other
related hazards covered
by programs including
fire and building codes,
DOT regulations (for
transportation only),
OSHA regulations, and
accident prevention and
preparedness regulations
under EPCRA and CAA
§H2(r)
Comments/Major Data
Gaps
Potential gap is diffi-
cult to characterize
because reactive wastes
are already regulated as
hazardous
Page 10-6
-------
descriptions do not, as noted above, identify any fires related to flammable solids. Also, as noted in
Chapter 3, various data searches failed to identify any incidents that could be unambiguously related to
flammable solids in non-hazardous industrial waste management units. At least one potential variety
of flammable solids, soils contaminated with petroleum byproducts, are explicitly excluded by statute
from RCRA Subtitle C jurisdiction.
Finally, the test methods referenced in the ignitability characteristic are outdated and need to
be revised. The U.S. Department of Transportation has promulgated new methods in different sections
of the Code of Federal Regulations. EPA, however, is not aware of any fires or other adverse events
arising from confusion over the proper test methods.
Corrosivity
The second panel in Exhibit 10-1 addresses potential gaps in the corrosivity characteristic.
Several potentially corrosive substances, primarily strong acids, are identified among the known and
possible non-hazardous industrial waste constituents. These compounds are not among the most
frequently detected groundwater contaminants in the release descriptions, however.1 No information
is available concerning corrosive non-liquids in the release descriptions.
A potential gap associated with the pH range of the corrosivity characteristic also was
identified. The release descriptions identify decreased or elevated pH levels in groundwater near
management units for a number of the industries. While the reported pH levels are not associated with
skin or eye injury or injury to biota, the appearance of elevated or depressed pH in groundwater after
dilution indicates that high- and low-pH wastes are frequently encountered among the non-hazardous
industrial wastes. The extent to which the pH of these wastes falls into the potential gap between the
existing pH limits in the corrosivity characteristic and possible more stringent limits is not known,
however.
The corrosivity characteristic also does not address corrosion of materials other than steel.
Specifically, the Agency has identified potential corrosion of plastics and clay (common materials used
in liners of non-hazardous industrial waste management units) as a potential gap. For example, the
plastic liners may be corroded by nonaqueous phase liquids (NAPLs) if present in significant amounts;
as is discussed in more detail in Section 4.2.3, a number of TC analytes and known and possible waste
non-hazardous industrial constituents could form NAPLs. In addition, certain ketones and alcohols
could dehydrate or otherwise adversely affect the physical integrity of clay liners.
Finally, the corrosivity characteristic excludes irritants and sensitizers. The Agency has found
a number of allergic sensitizers to be constituents of non-hazardous industrial wastes, including
ammonia, beryllium, cobalt, copper, nickel, nickel carbonyl, formaldehyde, isobutyl alcohol, n-dioctyl
phthalate, benzoic acid, and coal tars. Further analysis may identify other substances. While the
release descriptions do not report any incidents of allergic sensitization, dermatitis is one of the most
common occupational illnesses, and non-hazardous industrial waste could contribute to these potential
risks to waste management and transportation workers. Occupational Safety and Health Act
regulations prescribe measures to limit dermal exposures to hazardous substances in the workplace,
however. Thus, this problem is at least partially addressed by non-RCRA regulations.
1 "Fluorides/fluorine/hydrogen" (the slashes indicate that the exact chemical species is not identified) are among
the frequently detected constituents, but these detections most probably refer to fluoride ion, rather than to the acid.
Page 10-7
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Reactivity
The final panel of Exhibit 10-1 summarizes the information related to the potential gaps in the
reactivity characteristic. A major question for this potential gap is whether the over-broadness of the
definition has increased the occurrence of human health or environmental damages or risks due to
reactive materials. The release descriptions do not contain information related to violent chemical
reactions. Also, while some DOT-classified reactive chemicals are among the non-hazardous industrial
waste constituents, there is no evidence that would indicate whether these chemicals are present in
forms or concentrations that are reactive. The need to specify test methods is likewise linked both to
the severity of reactivity as a problem for non-hazardous industrial waste management operations, and
to the extent to which such issues are not already addressed by the DOT regulations, OSHA
regulations, or process safety management practices.
10.2.2 Potential Gaps Associated with TC Analytes
Exhibit 10-2 summarizes the analysis of five types of potential gaps associated with the
toxicity characteristic:
TC regulatory levels for the groundwater pathway;
Risks through non-groundwater pathways, including inhalation, surface water, and
indirect pathways;
Acute human health risks;
Risks to ecological receptors; and
Limitations in the TCLP.
Each of these gaps is discussed below, following a brief review of data applicable to all four potential
gaps.
One indication of the significance of these potential gaps is that 25 of the 40 TC analytes were
detected in at least one of the descriptions of releases from non-hazardous industrial waste
management units described in Chapter 2. Many are detected frequently above regulatory levels. Six
TC metals and arsenic are among the most commonly detected analytes in the release descriptions.
All TC analytes are regulated under federal and state regulatory schemes in addition to the
RCRA hazardous waste characteristics. The TC analytes are included in 40 CFR Part 261, Appendix
VHI, and therefore many wastes have been listed based on the presence of TC chemicals. Media-
specific regulatory programs also control individual analytes. MCLs or MCLGs have been
promulgated to limit exposures to about half the TC analytes in community drinking water systems.
Most volatile TC analytes are Hazardous Air Pollutants under the CAA, and most TC analytes have
OSHA Permissible Exposure Limits (PELs), which limit occupational exposures. CWA Ambient
Water Quality Criteria trigger regulatory control of most of the TC analytes through NPDES permits
and state surface water quality standards, although, as noted in Chapter 3, the TC regulatory levels
may not be adequately protective against surface water risks for some analytes.
Page 10-8
-------
Exhibit 10-2
Evaluation of Potential Gaps Associated with Toxicity Characteristic Analytes and TCLP
Potential Gap
Groundwater pathway
risks from wastes
below TC regulatory
levels
Uniform DAF value
potentially not
protective for some
TC constituents.
Inhalation risks were
not considered in
derivation of TC
levels. Volatile
organics pose such
risks.
Surface water risks to
human health were not
considered in the
derivation of TC
levels.
Nature of Risk
Wastes with TC constituents
below regulatory levels may pose
chronic health cancer risk >IO"5,
noncancer hazard quotient > 1 in
nearby populations exposed through
groundwater ingeslion.
For 16 TC crganics with inhalation
cancer risk data, risk > 10"' was
found for:
0 and 12 analytes in central
tendency and high-end surface
impoundments respectively; and
0 and 4 in central tendency and
high-end LAUs respectively.
For 4 TC organics with inhalation
non-cancer risk data, HQ > 1 was
found for:
3 or 4 of central tendency or high-
end respectively of both surface
impoundments and LAUs.
Potential chronic health cancer
risks >IO~5, noncancer risks HQ > 1
in nearby populations exposed to
surface water by consumptive use or
recreational use
Detection in Release
Descriptions
7 TC metals (lead,
chromium, arsenic,
cadmium, barium,
mercury, selenium) are
among top 20 frequently
detected constituents.
Other TC constituents
occurring > 5 times are
benzene, trichloro-
ethylene, vinyl chloride,
silver, chlorobenzene,
chloroform, and
tetrachloroethylene.
Vinyl chloride,
chloroform, chloroben-
zene, 1,4-dichlorobenzene
and carbon letrachloride
are among most fre-
quently detected analytes.
Toxic, bioaccumulative
constituents of potential
concern were not
identified frequently in
the release descriptions.
TRI Chemicals with
1994 Reported
Releases > Million
Ibs.
Methyl ethyl
ketone, trichloro-
ethylene, chromium
compounds, lead
compounds, chloro-
form, tetrachloro-
ethylene, benzene,
1,2-dichloroethane,
chromium, arsenic
and compounds.
chlorobenzene, vinyl
chloride
Methyl ethyl
ketone, chloroform,
1,2-dichloroethane,
vinyl chloride
Specific constitu-
ents of potential
concern were not
identified.
Affected Industries
> Industries with
frequent detections
of metals in release
descriptions include
chemicals, paper.
refuse systems.
industrial sand,
primary metals, and
others.
Chemicals, refuse
systems, and others
"
Not addressed
Affected
Management
Methods
Landfills, surface
impoundments, land
application units.
waste piles, poten-
tially others
Surface impound-
ments, land applica-
tion units, landfills,
and possibly waste
handling
Surface impound-
ments, landfills,
land application
units, waste piles .
Coverage by Other
Regulations
RCRA listings,
state Industrial D,
SDWA
RCRA listings.
state Industrial D,
CWA NPDES,
CAA, OSHA PELs
Intentional
discharges limited
by NPDES; state
CWA Industrial D
design requirements
limit unintentional
releases
Comments/Major Data
Gaps
Variability and
uncertainly in calculated
DAF values, depending
on modeling assumptions
Limited non-hazardous
industrial wasteslream
data
Most organic analytes
that exceed inhalation
risk thresholds are not
very persistent in either
soil or water.
Release descriptions
did not identify
inhalation problems.
Limited wasteslream
data
Risks may be significant
only in narrow range of
conditions.
Limited wasteslream
data
Release descriptions
include few surface water
releases.
Page 10-9
-------
Exhibit 10-2 (continued)
Evaluation of Potential Gaps Associated with Toxicity Characteristic Analytes and TCLP
Potential Gap
Indirect/food chain
pathway risks to
human health were not
considered in
derivation of TC
levels. Persistent and
bionccumulative
chemicals pose such
risks.
Acute adverse health
effects were not
considered in
derivation of TC
levels.
Ecological risks were
not considered in
derivation of TC
levels. TC
constituents include
potent ecotoxins.
persistent and
bioaccumulative
pesticides.
Nature of Risk
Potential human health risks from
consumption of fish, crops,
beef/dairy products
Persistent bioaccumulalive TC
analytes are chlorinated pesticides,
chloroform, hexachloro-1,3-
butadiene, mercury, arsenic, and
lead.
Screening analysis showed that
short-term concentrations of all
volatile TC organics calculated at
fenceline were for below applicable
short-term (occupational) exposure
standards
Unusual release events (e.g., fires
or explosions) could result in higher
exposures
Potential damage to nearby aquatic
ecosystems from releases to surface
water and through aquatic and
possibly terrestrial food chain
exposures from runoff
TC analytes with a ratio of TC
leachate concentration to AWQC >
10,000 include chlorinated pesti-
cides, chlorobenzene, lead, mercury,
pentachlorophenol, silver.
toxaphene, and
2,4,5-trichlorophenol.
Ratio is > 100,000 for mercury,
methoxychlor, silver, and toxaphene.
Detection In Release
Descriptions
Lead, mercury, arsenic,
chloroform were
frequently detected.
Persistent pesticides
were not frequently
detected.
Specific constituents of
potential concern were
not identified.
Lead, mercury, silver.
and chlorobenzene each
were delected at more
than 5 of 1 12 releases.
TRI Chemicals with
1994 Reported
Releases > Million
Ibs.
Lead compounds,
chloroform, arsenic
compounds
Specific constitu-
ents of potential
concern were not
identified.
Chlorobenzene
Affected Industries
Industries with
frequent detection
of metals include
chemical, paper.
and sanitary
services.
Not addressed
Chemicals, refuse
systems, paper,
primary metals, and
others
Affected
Management
Methods
Surface impound-
ments, land applica-
tion units, and
landfills
Not addressed.
Waste piles, land
application units.
surface impound-
ments, landfills
Coverage by Other
Regulations
RCRA listings,
slate Industrial D,
CWA NPDES.
CAA. F1FRA
OSHA PELs.
CAA
State Industrial D,
CWA effluent
limits, F1FRA
Comments/Major Data
Gaps
Limited data on
wasteslreams, releases to
various media, and
resulting damages
Acute hazards are
addressed by ICR
characteristics
Uncertainty in esti-
mating degradation and
dilution
Limited data on
wastestreains and
releases to various
pathways
Page 10-10
-------
Exhibit 10-2 (continued)
Evaluation of Potential Gaps Associated with Toxicity Characteristic Analytes and TCLP
Potential Gap
TCLP may not
accurately predict
leachate concentration
or risks for certain
wastes and units.
Nature of Risk
Release concentrations may be
higher or lower than predicted.
implying higher or lower exposure
concentrations and risks.
Main concerns are for oily wastes;
highly alkaline wastes; wastes with
multiple constituents; wastes dis-
posed in certain types of landfills;
some types of treated wastes; some
types of contaminated soil; and non-
groundwater pathways.
Detection In Release
Descriptions
Lead, cadmium,
chromium, arsenic,
barium, benzene.
selenium, lindane, and
vinyl chloride were
detected in groundwoter
at levels exceeding their
TC levels, indicating that
TCLP may have
underestimated the long-
term releases of some
wastes.
TRI Chemicals with
1994 Reported
Releases > Million
Ibs.
Chromium
compounds, lead
compounds, arsenic
compounds, and
vinyl chloride (of
those listed in prior
column)
Affected Industries
Not addressed
Affected
Management
Methods
AH types
Coverage by Other
Regulations
RCRA listings.
slate Industrial D;
states have
developed alter-
native leaching
procedures, e.g., Cal
WET
Comments/Major Data
Gaps
Limited data on
wastestreams and
management unit
environments
Waste heterogeneity.
sampling procedures.
sample preparation.
leaching procedure
contribute to uncertainty .
in test results.
1
Page 10-11
-------
TC Regulatory Levels for Groundwater
The first of the potential TC gaps concerns whether the existing leachate concentrations remain
demonstrably protective of human health through the groundwater pathway, given advances in
toxicological, fate, and transport data and modeling since the TC was promulgated. As noted in
Section 3.5.2, the only changes in toxicological values that have occurred since the TC was
promulgated are the reduction of the RfD for pentachlorophenol, promulgation of a cancer slope factor
for this compound, the reduction in the RfD for p-cresol, the replacement of the MCL for lead with a
lower action level, and replacement of the MCL for silver with an SMCL. Of these changes, only the
classification of pentachlorophenol as a carcinogen significantly changes the risk implicit in the TC
regulatory levels. EPA also has refined its approach for modeling the fate and transport of both
organic and inorganic constituents in groundwater. Most recently, groundwater risks were modeled for
the TC analytes in the HWIR-Waste proposed rulemaking. This modeling, which is still undergoing
revisions, was performed using some assumptions that differ significantly from those made in the
derivation of the TC regulatory levels. Nevertheless, the results, which are proposed health-protective
exit levels for releases to groundwater, can be interpreted to imply that some TC regulatory levels may
not protect human health to the extent originally intended. Without more detailed modeling that
duplicates, where appropriate, the TC input assumptions, no firm conclusions can be drawn about
which TC regulatory levels do or do not meet the original risk objectives, however.
Risks Through Non-Groundwater Pathways
Another major potential TC gap relates to exposures associated with inhalation, surface water,
and indirect exposure pathways. These pathways were not considered when the TC was promulgated.
The results of the proposed HWIR-Waste modeling also provide evidence that non-groundwater
pathway risks may be important for several TC analytes. For nine of these substances, non-
groundwater indirect exposures resulted in the highest risks and thereby determined the HWIR-Waste
proposed exit concentrations. These pathways included both air and surface water. In most cases, the
proposed exit concentrations for the indirect pathways are considerably lower than those based only on
the groundwater pathway. These modeling results provide further evidence that the TC levels may not
be sufficiently protective for some highly toxic, volatile, persistent, and/or bioaccumulative chemicals
when pathways other than groundwater are considered.
The screening-level modeling in Section 3.5.3 identified various TC constituents that may
present inhalation risks when present in wastes at TC regulatory levels. For example, estimated
lifetime cancer risks exceeded 10-5 for 12 of the 16 TC analytes for which EPA has promulgated
inhalation Unit Risk values, .assuming management in "high-end" surface impoundments. Cancer risks
exceeded 10-5 for 4 of these 16 analytes when management in a high-end land application unit (LAU)
was assumed. None of the analytes posed cancer risks above this level when managed in "central
tendency" units.
The Agency has promulgated inhalation pathway Reference Concentrations for only four TC
analytes (chlorobenzene, methyl ketone, nitrobenzene, and 1,4-dichlorobenzene). When releases were
modeled from high-end impoundments or LAUs, all four analytes had inhalation pathway hazard
quotients above 1.0. When the central tendency impoundments are modeled, three of the four analytes
(all but 1,4-dichlorobenzene) still have HQ values above 1.0.
All the analytes with screening-level risk estimates above levels of potential concern were
found in the release descriptions; several of them occur frequently in the release descriptions. Four of
Page 10-12
-------
these constituents are among the chemicals with total TRI release volumes greater than one million
pounds, as noted in Exhibit 10-2.
EPA did not perform quantitative risk modeling of surface water and indirect pathways.
Instead, the Agency reviewed the toxicity and fate and transport parameter values for the TC analytes
to develop a qualitative indication of the potential risks to human health that they might present when
managed in Subtitle D units, as discussed in Section 3.5.4. A substantial proportion of the analytes
have properties, such as volatility, persistence in air, soil, and water, and high bioaccumulation
potential, that suggest potential exposure through surface water or indirect pathways might result in
significant risks. The proposed HWIR-Waste modeling results for indirect pathways discussed above
suggest the need for more detailed modeling, using assumptions consistent with those used to derive
the TC regulatory levels, to better determine which indirect pathways are the most important for which
TC analytes.
Acute Adverse Effects
The TC was originally established based on the need to protect individuals from adverse health
effects due to chronic exposures to the TC constituents consumed in groundwater. This approach to
protecting against groundwater exposure risks is conservative because the relatively long time scale
generally involved in groundwater transport to receptors means that limiting concentrations in any time
period to the low chronic risk-based levels also will protect against short-term adverse effects. This
relationship may not apply to exposure through pathways not involving slow releases to groundwater.
For example, the rapid evaporation of volatile chemicals from a ruptured container, the catastrophic
release due to overtopping of a surface impoundment, or runoff erosion from an extreme storm event
has the potential to result in short-term (acute) exposures to humans and environmental receptors.
Thus, EPA evaluated the potential for acute adverse effects associated with rapid volatilization
of chemicals from land management units. This screening-level analysis indicated that the short-term
concentrations of all volatile TC analytes calculated at the fenceline were far below applicable short-
term exposure standards (in this case, occupational exposure standards). This simple modeling does
not unconditionally eliminate the possibility of adverse effects from acute exposures to the TC
analytes. Unusual release events, such as fires or explosions, could result in higher exposures than
calculated assuming simple volatilization. In addition, high winds or other events could result in high
concentrations of particle-bound metals and other nonvolatile analytes. The potential for these kinds
of release events strongly depends on specific waste characteristics, site conditions, and management
practices.
Risks to Ecological Receptors
The next potential gap in the TC is its lack of specific consideration of potential adverse
effects on ecological receptors. Section 3.5.7 found that several TC analytes are highly toxic to
aquatic biota, which suggests that this potential gap may be significant. Some of these constituents
occur frequently in the release descriptions. One potent ecological toxicant (chlorobenzene) is among
chemicals with TRI releases greater than one million pounds. Several TC analytes, including the
chlorinated pesticides, chlorobenzene, mercury, and silver have TC levels greater than 1,000 times
their respective AWQC, which indicates a risk to aquatic biota value if dilution after release is less
than 1,000-fold. Mercury, methoxychor, silver, and 2,4,5-trichlorophenol have TC levels more than
10,000 times their AWQCs. In addition, as discussed in more detail in Section 10.2.4, several TC
analytes (cadmium, heptachlor, heptachlor oxide, lead, mercury, methoxychlor, and toxaphene) have
Page 10-13
-------
been identified as suspect endocrine disrupters for wildlife, as well as humans. All these lines of
evidence support the importance of this potential gap. Some ameliorating considerations, however,
include the relative lack of evidence for environmental damage in the release descriptions summarized
in Chapter 2, and the existing bans and/or use restrictions on many of the TC pesticides, which
comprise most of the potent ecological toxicants.
TCLP Limitations
The final potential gap in the TC characteristic is the limitations in the ability of the TCLP to
accurately predict releases of hazardous constituents from wastes. The Agency has received numerous
comments and data on the utility of the TCLP in general and for specific wastes and environments.
Potential limitations of the method include difficulties in performing the analysis on oily, hydrophobic
wastes and in simulating leachate characteristics for highly alkaline wastes, certain types of landfill
environments, long-term mobility of organics in some treated (non-hazardous) wastes, and some
contaminated soils. Furthermore, the TCLP was not designed to simulate releases into non-
groundwater pathways (e.g., air).
In the context of this Scoping Study, EPA has not identified any significant new information
bearing on the magnitude of this potential gap. The Agency has reviewed other possible leaching
methods (such as the SPLP and Cal WET methods), but has not found compelling evidence that they
are more appropriate for general use than the TCLP. The high frequency of occurrence of TC analytes
in groundwater above MCLs or HBLs near non-hazardous industrial waste facilities, as shown in the
release descriptions, suggests that the TCLP may not adequately detect situations that could result in
harm to human health or the environment. The blame cannot unambiguously be placed on the TCLP,
however. Even if the TCLP accurately predicts TC leachate levels, site-specific fate and transport
processes (e.g., dilution by a factor of less than 100) and waste management practices could result in
the exceedances of MCLs and other regulatory levels.
10.2.3 Potential Gaps Associated with Non-TC Waste Constituents
Exhibit 10-3 summarizes the evaluation of potential gaps associated with non-TC chemicals
that are known or possible non-hazardous industrial waste constituents. Separate evaluations are
presented for each of the 10 categories of chemicals identified in Chapter 4, which are associated with
the groundwater, inhalation, or indirect pathways:
Metals and other inorganics;
Volatile chlorinated organics;
Volatile hydrocarbons;
Other volatile drganics;
Pesticides and related compounds;
Phthalate esters;
Phenolic compounds;
Polycyclic aromatic hydrocarbons;
Other semivolatile organic compounds; and
LNAPLs and DNAPLs.
Nature of Risk. A number of chemicals in some of the groups listed above are suspect
carcinogens. Other chemicals have the potential to cause reproductive and/or developmental effects in
Page 10-14
-------
Exhibit 10-3
Evaluation of Potential Gaps Associated with Non-TC Chemicals
Chemical
Type
Nature of Risk
Presence In
Non-Hazardous
Industrial
Waste"
Frequently
Detected Con-
stituents in
Release Descrip-
tions
TR! Chemicals
with 1994
Reported
Releases > One
Million IDS.
Affected Indus-
tries
Affected Manage-
ment Methods
Potential Coverage by
Other Regulations
Comments/Major
Data Gaps
GROUNDWATER PATHWAYS
Metals/Inorga-
nics
Volatile
Chlorinated
Organics
Volatile
Hydrocarbons
Potential cancer risks
> I0~5 and noncancer
risks of HQ>I
Potential cancer risks
> IO'5 and noncancer
risks of HQ>I
Many of these chem-
icals are suspect carcin-
ogens.
Potential cancer risks
> IO"5 and noncancer
risks of HQ>I.
61 elements,
compounds, or
families of com-
pounds; most
important are
probably the
metals.
beryllium, cop-
per, manganese.
nickel, zinc,
cyanides
45 compounds
13 compounds
Beryllium,
manganese, zinc,
copper, nickel.
cyanides
Methylene
chloride, ethylid-
ene dichloride
Toluene,
xylenes ,
;
Copper, zinc.
manganese, cyan-
ides, nickel, anti-
mony
Methylene
chloride, trichloro-
ethene, 1,1,1-tri-
chloroelhane,
chloroinethane,
Freon 113
Toluene,
xylenes, styrene,
ethylbenzene.
cumene
Chemicals,
refuse systems.
paper have about
66 percent of
detections in
release descrip-
tions; 10 other
industries have
frequent detections
* Refuse systems,
paper, and chemi-
cals have about 85
percent of detec-
tions
Chemicals,
refuse systems,
and paper have 80
percent of detec-
tions
78 percent of
detections from
landfills; 15 per-
cent from surface
impoundments; 5
percent from land
application units.
79 percent of
detections from
landfills; 13 per-
cent from surface
impoundments.
68 percent of
detections from
landfills; 27 per-
cent from surface
impoundments.
State Industrial D; Cali-
fornia TC includes 10
additional metals;
Michigan TC includes
copper and zinc; many
have MCLs or SMCLs
Slate Industrial D; most
in Appendix VIII; RCRA
listings; California TC
includes l,2-dibromo-3-
chloropropane; many have
MCLs. MCLGs
State Industrial D; RCRA
listings; all in Appendix
VIII; most have MCLs
and/or AWQCs
Exposure at indi-
vidual residential
wells not known
Limited data on
wastestream and waste
management practices
contributing to
groundwater releases
Petroleum hydrocar-
bons exempt from
RCRA
Limited data on
waslestreams and
management practices
conlributing
-------
Exhibit 10-3 (continued)
Evaluation of Potential Gaps Associated with Non-TC Chemicals
Chemical
Type
Other Volatile
Organics
Phenolic Com-
pounds
LNAPLs and
DNAPLs
Nature of Risk
> IO*1 and noncancer
risks of HQ>1
Highly variable
loxicity and fate and
transport properties
risks of HQ>1
Facilitated transport of
organic chemicals from
containment
Long-lasting, difficult
to remediate reservoir of
groundwater contamina-
tion (DNAPL)
Presence In
Non-Hazardous
Industrial
Waste8
58 compounds
33 potential
DNAPL formers,
13 potential
LNAPL formers
Frequently
Detected Con-
stituents In
Release Descrip-
tions
Acetone
Phenol
Potential
LNAPL/DNAPL
formers were
found in many
release descrip-
tions
LNAPLs/
DNAPLs were
not reported as
problem in any
release
descriptions.
possibly because
of limited report-
ing requirements
TRI Chemicals
with 1994
Reported
Releases > One
Million IDS.
Methanol,
methyl ethyl
ketone, methyl-
isobutyl ketone,
n-bulanol, formal-
dehyde, acetoni-
trile, acetaldehyde,
acrylonitrile, vinyl
acetate, propylene
oxide
«. Phenol; com-
bined cresols
release exceeds
one million
pounds
8 compounds
plus the phlhalale
esters (combined)
Affected Indus-
tries
Chemicals,
refuse systems,
and paper indus-
tries have 88 per-
cent of detections
10 industries
with detections;
among the most
widespread of
constituent classes,
despite low num-
ber of detections
LNAPLs/
DNAPLs not
reported in release
descriptions
Affected Manage-
ment Methods
75 percent of
detections from
landfills and the
remainder from
surface impound-
ments.
56 percent of
detections at land-
fills; 36 percent at
surface impound-
ments; and 8
percent at land
application units.
No data.
Management
priorities are key
to DNAPL genera-
tion.
Potential Coverage by
Other Regulations
Stale Industrial D; most
in Appendix VIII; RCRA
listings; California TC
includes acrylonilrile; few
have MCLs, MCLGs
State Industrial D; all in
Appendix VIII
State Industrial D; RCRA
listings; some chemicals
have MCLs
Comments/Major
Data Gaps
Wide range of lexic-
ological, fate and
transport properties
Limited data on
wastestreams and
management practices
contributing to
groundwater releases
Most compounds are
of relatively low
toxicity, biodegradable
at low concentrations
Limited data on
wastestreams
Frequency of NAPL
problems in non-haz-
ardous waste appears
to be infrequent, espe-
cially in recent years
Limited wasteslream
and waste manage-
ment data
Page 10-16
-------
Exhibit 10-3 (continued)
Evaluation of Potential Gaps Associated with Non-TC Chemicals
Chemical
Type
Other Semi-
volatile
Organic Com-
pounds
Nature of Risk
Potential cancer risks
> I0~5 and noncancer
risks of HQ>I
Some are persistent
and/or bioaccumulative.
Highly variable fate
and transport properties
Presence in
Non-Hazardous
Industrial
Waste8
67 compounds
Frequently
Detected Con-
stituents in
Release Descrip-
tions
None
TRI Chemicals
with 1994
Reported
Releases > One
Million Ibs.
Formic acid,
acrylic acid, naph-
thalene
Affected Indus-
tries
Chemicals indus-
try has 45 percent
of detections,
remainder in five
other industries
Affected Manage-
ment Methods
Approximately
equal frequency in .
landfills and sur-
face impoundment
releases
Potential Coverage by
Other Regulations
State Industrial D; many
in Appendix VIII; RCRA
listings; a few have MCLs;
PCBs covered by TSCA
and some state hazardous
waste regulations
INHALATION PATHWAYS
Volatile Chlo-
rinated Orga-
nics
f
Volatile
Hydrocarbons
Other Volatile
<0rgonics
Potential cancer risks
> IO"5 and noncancer
risks of HQ>I
Many of these chemi-
cals are suspect carcino-
gens
Potential noncancer
risks of HQ>I
Benzene is the only
carcinogen
Potential cancer risks
> IO"5 and noncancer
risks of HQ>I
Highly variable
toxicity and fate and
transport properties
45 compounds
13 compounds
58 compounds
Melhylcne
chloride,
elhylidene
dichloride
Toluene,
xylenes
Acetone
Methylene chlo-
ride, trichloroeth-
ene, 1,1,1-trichlo-
roethane, chloro-
methane, Freon
113
Toluene,
xylenes, styrene,
elhylbenzene,
cumene
Methanol,
methylisobutyl
ketone, n-bulanol,
formaldehyde,
acetinilrile,
acetaldehyde,
acrylonilrile, vinyl
acetate, propylene
oxide
Refuse systems,
paper, and chemi-
cals, have about
85 percent of
detections
Chemicals,
refuse systems,
and paper have 80
percent of detec-
tions
Chemicals refuse
systems, and paper
industries have 88
percent of detec-
tions
79 percent of
detections from
landfills; 13 per-
cent from surface
impoundments
68 percent of
detections from
landfills; 27 per-
cent from surface
impoundments
75 percent of
detections from
landfills and re-
mainder from
surface impound-
ments.
State Industrial D; most
in Appendix VIII; RCRA
listings; California TC
includes 1 ,2-dibromo-3-
chloropropane; majority
are CAA HAPs; vinyl
chloride has NESHAP;
many have OSHA PELs
State Industrial D; all in
Appendix VIII RCRA
listings; all are CAA HAPs
State Industrial D; most
in Appendix VIII; RCRA
listings; California TC
includes acrylonitrile; most
are CAA HAPs; most have
OSHA PELs
Comments/Major
Data Gaps
Highly variable lexi-
cological, fate, and
transport properties
Limited data on
wasteslreams and
management practices
contributing to
groundwater releases
Limited data on
wasteslream and waste
management practices
contributing to air
releases
Petroleum hydrocar-
bons exempt from
RCRA
Limited data on
wasteslreams and
management practices
contributing most to
air releases..
Wide range of lexi-
cological, fate and
transport properties
Limited data on
wasteslreams and
management practices
contributing to air
releases
Page 10-17
-------
Exhibit 10-3 (continued)
Evaluation of Potential Gaps Associated with Non-TC Chemicals
-
Chemical
Type
Related Com-
pounds
Aromatic
Hydrocarbons
Other
Semivolatile
Organic Com-
pounds
Nature of Risk
Potential cancer risks
> 10"s and noncanccr
risks of HQ>I
Some suspect endo-
crine disrupters
Possible reproductive
toxicity and human
development effects
Many are persistent
and bioaccumulative.
Potential cancer risks
r
> I0's.
Some are persistent
and bioaccumulative.
Potential cancer risks
*
> 10~J and noncancer
risks of HQ>I
Some are persistent
and/or bioaccumulative.
Highly variable fate
and transport properties
Presence in
Non-Hazardous
Industrial
Waste"
103 compounds
. » 19 compounds
67 compounds
Frequently
Detected Con-
stltuents In
Release Descrip-
tions
None
None (but
PAHs are not
mobile in
groundwater)
None
TRI Chemicals
with 1994
Reported
Releases > One
Million Ibs.
None
0 None
,
Formic acid.
acrylic acid,
naphthalene
Affected Indus-
tries
Chemicals indus-
try has 80 percent
of detections;
refuse systems
have 10 percent
9 Relatively equal-
ly frequent in
detections from
petroleum refining
and chemicals
industries; low
frequency overall
Chemicals indus-
try has 45 percent
of detections.
remainder in five
other industries
Affected Manage-
ment Methods
87 percent of
detections at sur-
face impound-
ments; remainder
at landfills
Relatively equal-
ly frequent at
landfills and sur-
face impound-
ments
Approximately
equal frequency in
landfills and sur-
face impoundment
detections
Potential Coverage by
Other Regulations
State Industrial D; RCRA
listings; most in Appendix
VIII; several are CAA
HAPs; FIFRA banned pro-
duction or restricted use of
many
State industrial D; many
have CAA HAPs; many
have OSHA PELs
State Industrial D; many
in Appendix VIM; RCRA
listings; many have OSHA
PELs; some are CAA
HAPs
Comments/Major
Data Gaps
Future generation is
unclear because of
production and use
restrictions; potential
presence in
remediation waste
may merit examining
Limited data on
management practices
contributing to air
releases
Highly variable
lexicological, fate, and
transport properties
Limited data on
waslestreams and
management practices
contributing to non-
groundwater releases
Highly variable
lexicological, fate, and
transport properties
Limited data on
wastestreams and
management practices
contributing to non-
groundwater releases
Page 10-18
-------
Exhibit 10-3 (continued)
Evaluation of Potential Gaps Associated with Non-TC Chemicals
Chemical
Type
Nature of Risk
INDIRECT/FOOD-CHAIN PATHWAYS
Pesticides and
Related Com-
pounds
Phlhalale
Esters
Phenolic Com-
pounds
Potential cancer risks
> I0~5 and noncancer
risks of HQ>I
Some suspect endo-
crine disrupters.
Possible reproductive
toxicity and human
development effects
Many are persistent
and bioaccumulative.
Potential cancer risks
> IO"5 (one compound)
Suspect endocrine
disrupters
Possible reproductive
toxicity, human devel-
opment effects
Several are persistent
and bioaccumulative.
Potential noncancer
risks of HQ>I
Presence In
Non-Hazardous
Industrial
Waste"
Frequently
Detected Con-
stituents in
Release Descrip-
tions
TRI Chemicals
with 1994
Reported
Releases > One
Million Ibs.
Affected Indus-
tries
103 compounds
6 compounds
13 compounds
None
None
Phenol
None
None; combined
phlhalate ester
releases exceed
one million
pounds, however
.
Phenol; com-
bined cresols
release exceeds
one million
pounds
Chemicals indus-
try has 80 percent
of detections;
refuse systems
have 10 percent
Chemicals indus-
try has 70 percent
of detection;
petroleum industry
has IS percent
10 industries
with detections;
among the most
widespread of
constituent classes.
despite low num-
ber of detections
Affected Manage-
ment Methods
87 percent of
detections at sur-
face impound-
ments; remainder
at landfills
54 percent of
detections at sur-
face impound-
ments and 38
percent at landfills
56 percent of
detections at land-
fills; 36 percent at
surface impound-
ments; 8 percent at
land application
units
Potential Coverage by
Other Regulations
State Industrial D; RCRA
listings; most in Appendix
VIII; several have
AWQCs; FIFRA banned
production or restricted use
of many
State Industrial D; di(2-
ethylhexyOphthalate has
MCL and AWQC
State Industrial D; all in
Appendix VIII; several
have AWQC
Comments/Major
Data Gaps
Future generation is
unclear because of
production and use
restrictions; potential
presence in
remediation waste
may merit examining.
Limited data on
management practices
contributing to
releases
High-volume chemi-
cals with high
exposure potential, but
often low toxicity
Limited understand-
ing of dose-response
relationships,
especially for endo-
crine disruption
Unclear significance
of exposures from
non-hazardous waste
relative to other
sources
Most compounds are
of relatively low tox-
icity, biodegradable at
low concentrations
Limited data on
, wastestreams
Page 10-19
-------
Exhibit 10-3 (continued)
Evaluation of Potential Gaps Associated with Non-TC Chemicals
Chemical
Type
Polycychc
Aromatic
Hydrocarbons
Semivolatile
Organic Com-
pounds
Nature of Risk
Potential cancer risks
>W5
Some are persistent,
bioaccumulalive.
> I0~5 and noncancer
risks of HQ>I
' Some are persistent
and bioaccumulalive.
Highly variable fate
and transport properties
Presence in
Non-Hazardous
Industrial
Waste*
19 compounds
67 compounds
Frequently
Detected Con-
stituents In
Release Descrip-
tions
None (but
PAHs ore not
mobile in
groundwaler)
TRI Chemicals
with 1994
Reported
Releases > One
Million Ibs.
None
Formic acid,
acrylic acid, naph-
thalene
i
Affected Indus-
tries
Relatively equal-
ly frequent in
detections from
petroleum refining
and chemical
industries; low
frequency overall
Chemicals and
allied products
have 45 percent of
detections,
remainder in five
other industries
Affected Manage-
ment Methods
Relatively equal-
ly frequent at
landfills and sur-
face impound-
ments
Approximately
equal frequency in
landfills and sur-
face impoundment
detections
Potential Coverage by
Other Regulations
Slate Industrial D; most
have CWA effluent limits;
a few have AWQC; many
are CAA HAPs
State Industrial D; many
in Appendix VIII; RCRA
listings; a few have
AWQC
Comments/Major
Data Gaps
Highly variable
lexicological, fate, and
transport properties
Limited data on
waslestreams and
management practices
contributing to non-
groundwater releases
Highly variable
lexicological, fate, and
transport properties
Limited data on
wasteslreams and
management practices
contributing to non-
" Source: Exhibits 4-2 and 4-8.
Page 10-20
-------
humans and ecological receptors. These and other indicators of hazard, combined with indicators of
exposure potential, demonstrate the potential for risks to human health or the environment.
Presence in Non-Hazardous Industrial Waste. The numbers of chemicals in the various classes
that are known or possible non-hazardous industrial waste constituents varies widely:
103 pesticides and related compounds,
67 other semi-volatile organic compounds,
61 metals or other inorganics,
58 other volatile organics,
45 volatile chlorinated organics;
46 NAPL formers (30 DNAPL formers and 9 NAPL formers),
19 polycyclic aromatic hydrocarbons,
13 volatile hydrocarbons,
13 phenolic compounds, and
6 phthalate esters.
Frequently Detected Constituents in Release Descriptions. Six non-TC metals are among the
most frequently occurring analytes in the release descriptions, along with three volatile chlorinated
organics, one other volatile organics, and one phenolic compound. The other classes of chemicals
were not detected frequently in the release descriptions, which predominately included groundwater
contamination. The constituents found in the release descriptions, however, frequently violated MCLs
and other health-based levels.
TRI Chemicals with 1994 Reported Releases Exceeding One Million Pounds. These broad
categories of potential gaps include many chemicals with high TRI release volumes. In the case of the
non-TC metals and other inorganics, copper, zinc, manganese, and cyanides (as CNH) fell into this
category. As was the case for the frequency of occurrence in the release descriptions, several volatile
organic waste constituents (chlorinated and nonchlorinated) that have high TRI release volumes are TC
analytes. None of the pesticides, phthalate esters, or PAHs were among the chemicals with TRI
releases greater than one million pounds. Two phenolic compounds and three semivolatile organics
were among the waste constituents with the highest TRI releases. Many of the potential NAPL
forming compounds also are high-release compounds.
Affected Industries. A relatively small number of industries tend to account for the bulk of
the occurrences of most categories of wastes with chemicals of concern. For almost all chemical
classes, most detections of chemicals constituents2 identified in the release descriptions were
associated with three industry groups: chemicals and allied products, refuse systems, and paper and
allied products. Phenolic compounds diverge from this pattern. The three industries identified above
account for only about 35 percent of the releases of such compounds, and 8 other industries had
detections of phenolic constituents.
Affected Management Methods. As noted in Chapter 8, about 65 percent of the release
descriptions were associated with landfills, 28 percent with surface impoundments, and 11 percent
from land application units, 4 percent from waste piles, with the other management units accounting
2 Each chemical detected at a release site constitutes one detection. Thus, each release may have multiple
detections (i.e., multiple constituents) and each chemical may have multiple detections (i.e., be found at multiple
releases).
Page 10-21
-------
for less than 1 percent each. (Several release descriptions involved more than one facility.) This
pattern generally applies to the individual classes of chemicals, with a few significant exceptions.
Since metals and inorganics were detected much more often than other constituents, data on these
detections dominate the overall pattern. The other classes of chemicals with relatively high numbers
of detections (volatile hydrocarbons, other volatile organics, phenolic compounds, and chlorinated
volatile organics) were most commonly found in landfill releases, like the metals. For some chemical
classes with relatively low numbers of detections, such as other semivolatile organics, phthalate esters,
and PAHs, the proportions of detections from landfills and surface impoundments is almost equal, with
few releases are reported from other management units.
Potential Coverage by Other Regulations. As noted in Chapter 10, the chemicals associated
with potential gaps are subject to regulatory requirements that have some potential for controlling risks
to human health and the environment associated with nonhazardous industrial waste management.
Since the bulk of these chemicals are included in 40 CFR Part 261, Appendix VII, some wastes
containing these chemicals are RCRA listed hazardous wastes. Of course, other wastes with these
constituents are not listed.
The design and operation of non-hazardous industrial waste management facilities managing
all of the various classes of waste constituents is largely under the control or potential control of state
Industrial D programs. All of these programs include a federally-mandated minimum set of design
and monitoring requirements for landfills. In some states, as discussed in Chapter 10, these minimum
requirements have been expanded for certain types of waste management units, wastes, and/or
constituents. These requirements, however, vary considerably from state to state. The appearance of
various chemicals in groundwater at levels exceeding regulatory standards suggests that the control of
these chemicals under state Subtitle D programs may not afford the intended level of protection
nationwide.
The various chemical classes also are subject to medium-specific regulations under Safe
Drinking Water Act, Clean Air Act, and Clean Water Act. Most of the metals and commonly
occurring inorganic and organic analytes have MCLs established to protect drinking water quality.
Many of the volatile chemicals are CAA Hazardous Air Pollutants (HAPs). The effectiveness of this
designation in protecting against exposures from waste management is unclear, however, because the
regulatory requirements apply only to facilities emitting more than 10 tons of HAPs per year. Vinyl
chloride is also controlled by a National Emission Standard for Hazardous Air Pollutants, which is
risk-based and protective to roughly the same risk level as the TC. Some of the pesticides, identified
as being among the most potentially hazardous waste constituents in Chapter 4, are already banned or
strictly limited in their use by FIFRA.
10.2.4 Potential Gaps Associated With Resource Damage and Large-Scale
Environmental Problems
Chapter 5 briefly evaluated the following potential gaps in the hazardous waste characteristics
related to the following natural resource damages and large-scale environmental problems:
Natural Resource Damages
Groundwater pollution that may not present a health risk;
Odor problems;
Page 10-22
-------
Large-Scale Environmental Problems
Air deposition to the Great Waters;
Damages from airborne particulates;
Global climate change;
Potential damages from endocrine disrupters;
Red tides;
Stratospheric ozone depletion;
Tropospheric ozone and photochemical air pollution; and
Water pollution.
At this time, the Agency does not plan to further consider any of these potential gaps, except possibly
air deposition and endocrine disruptions. These two potential gaps are discussed below and
summarized in Exhibit 10-4.
Air Deposition to the Great Waters
Few data are available on the contribution of non-hazardous industrial waste management to
the deposition of toxic particulates (including toxic metals and persistent chlorinated organic
chemicals) in the Great Waters ecosystems. While non-hazardous industrial waste constituents include
toxic metals such as cadmium, lead, and mercury, the extent of their long-range transport is unknown.
Persistent chlorinated organic chemicals also are among non-hazardous industrial waste constituents.
Many of them have been banned from manufacture or further use and therefore are unlikely to be
managed in significant quantities as non-hazardous industrial wastes. They may, however, continue to
be found in remediation wastes.
Potential Damages from Endocrine Disrupters
The next potential gap is exposure to suspect endocrine disrupters. Depending upon what
criteria are used to identify these constituents, 28 suspect endocrine disrupters have been found among
the TC analytes and known or possible non-hazardous industrial waste constituents. Only the metals
are encountered frequently in the release descriptions, however. These metals are most commonly
present in releases detected from facilities in the chemicals and allied products, refuse systems, paper
and allied products, industrial sand, and primary metals industries. These releases are most often seen
from landfills, followed by surface impoundments, based on the release descriptions summarized in
Chapter 2.
One suspect endocrine disrupter, styrene, is high on the TRI list, having total releases of 40
million pounds in 1994. Almost all of the styrene releases are to air, with well under one million
pounds being released to land. Releases of the phthalate esters as a class also exceed one million
pounds, although the releases of these compounds individually are all less than one million pounds.
The use of many suspect endocrine disrupting pesticides has been banned or strictly limited.
A significant portion of the endocrine disrupters are TC analytes or otherwise listed in 40 CFR Part
261, Appendix VEQ. The greatest uncertainty concerning this potential gap is a lack of knowledge
about dose-response relationships for single and multiple agents, and the relative contribution of
non-hazardous industrial waste management to the total exposure of human and environmental
receptors.
Page 10-23
-------
Exhibit 10-4
Evaluation of Potential Gaps Associated With Certain Large-Scale Environmental Problems
Potential Gap
Air Deposition (o
the Great Waters
Potential Damage
from Endocrine
Disrupters
Nature of Risk
Adverse ecological
effects on Great
Lakes, Chesapeake
Bay, Lake
Champlain, and
coastal water
ecosystems
Impaired
reproduction and
developmental
disorders among
humans and wildlife
Presence In Non-
Hazardous
Industrial Waste
Many constituents,
such as pesticides.
PCBs, dioxins,
cadmium, lead, and
mercury
30 suspect
endocrine disrupters
Frequently
Detected
Constituents In
Release
Descriptions
Lead, cadmium,
mercury
Pesticides were
not frequently
detected.
Cadmium, lead,
and mercury
TRI Chemicals
with 1994
Reported Releases
> Million Ibs.
Lead compounds
Styrene, lead
compounds
Affected Industries
Chlorinated organics
are found in release
descriptions from only
a few industries and
found seldom therein
Metals are found
frequently in release
descriptions from many
industries
Most major
generating industries
Releases
descriptions found
them in 12 industries.
with 70 percent of the
detections in the
chemicals, paper, and
sanitary services
industries.
Affected
Management
Methods
Metals releases
predominantly from
landfills and surface
impoundments
Pesticide releases
predominantly from
surface
impoundments
68 percent of
detections in release
descriptions were
from landfills and 24
percent from surface
impoundments.
Potential Coverage
by Other
Regulations
CAA Section
1 12(m) and National
Emissions Standards
for Hazardous Air
Pollutants
RCRA listings.
F1FRA, SOW A,
CWA
Comments/Major
Data Gaps
Limited data on
air deposition
contributions from
non-hazardous
industrial waste
management
Uncertainty about
regional transport
patterns
Limited waste
stream and release
data
Dose-response
data for exposure to
single or multiple
agents is lacking
Page 10-24
-------
10.2.5 Gaps Associated with State TC Expansions and Listings
A number of states have expanded their hazardous waste program to regulate additional waste
as hazardous. These state expansions include:
Adding constituents to the list of TC analytes. These additional constituents
include zinc, other metals, PCBs, pesticides, dioxins, and potential carcinogens.
Lowering existing TC regulatory levels. For example, California lowered the
TC regulatory level for pentachlorophenol from 100 mg/1 to 1.7 mg/1.
Specifying alternative testing methods for identifying toxic hazardous
waste. For example, California requires use of the Wet Extraction Test (WET)
in addition to the TCLP. This test identifies several metal-containing wastes as
hazardous that are generally not identified as hazardous using the TCLP.
Using alternative approaches (other than listing constituents and
regulatory levels) to identify toxic hazardous wastes. For example, both
California and Washington have established toxicity criteria for wastes based
on acute oral LD50, acute dermal LD50, acute inhalation LC50, and acute
aquatic 96-hour LC50 of the wastestreams taken as a whole. A waste is
designated hazardous if a representative sample of the waste meets any of the
acute toxicity criteria. In addition, California's regulations state that a waste
exhibits the characteristic of toxicity if the waste, based on representative
samples, "has shown through experience or testing to pose a hazard to human
health or environment because of its carcinogenicity, acute toxicity, chronic
toxicity, bioaccumulative properties or persistence in the environment."
Listing additional wastes as hazardous. The most common state-only listed
wastes are PCBs and waste oil. At least four states include additional "F"
Wastes; three include additional "K" wastes; five include additional "P" wastes;
and six include additional "U" wastes.
Restricting exemptions from the federal rules. Examples include chromium-
bearing wastes from leather tanning and finishing, various special wastes,
certain arsenical-treated wood wastes, petroleum contaminated media and
debris that fail the TC, certain injected groundwater, used CFC refrigerants that
are reclaimed, and non-terne plated used oil filters.
Thus, several states appear to be regulating a significant number of wastes as hazardous that are not
covered under federal RCRA regulations. These expansions reflect state judgments about gaps in the
federal program and thereby constitute potential gaps that may merit further investigation. State
expansions have filled these gaps, but only in the specific states with such expansions. Such potential
gaps are possibly not being filled in die remaining states that have not expanded the federal hazardous
waste definitions.
Page 10-25
-------
10.2.6 Major Data Gaps and Uncertainties
The significance of potential gaps in the hazardous waste characteristics directly depends on
the magnitude of risks that are not addressed by the current characteristics or other programs. Thus,
data gaps in the Agency's ability to assess these risks are critical.
A key step in any risk analysis is characterizing the sources of releases of toxic or otherwise
hazardous materials to the environment. Thus, possibly the most important data gap is the lack of
current data on the generation, composition, and management of non-hazardous industrial wastes.
EPA's most recent comprehensive data on these topics are approximately a decade old. Many of the
data are even older. While the basic nature of non-hazardous industrial wastes and waste management
practices are not likely to have changed dramatically, nonetheless, some important changes are likely
to have occurred because of regulatory, economic, and technical developments since the data were
gathered.
Additional data gaps relate to exposure potential. Because of the lack of site-specific data, the
Agency had to rely primarily on proxies for exposure and risk potential. Environmental fate, transport,
and lexicological parameters have been used as a primary screening criteria to identify and evaluate
hazards. As noted in Chapter 5, consistent and reliable data related to these properties are available
for only a relatively-limited portion of the universe of chemicals under consideration.
Likewise, the Agency has no direct data on the amounts of certain constituents released from
non-hazardous industrial waste management units. Instead, 1994 TRI release data were used as
proxies for such data. Another data source the Agency employed to assess exposure potential was the
release descriptions from non-hazardous industrial waste management facilities. While these data
provide direct evidence of environmental contamination, it is often not clear whether the management
practices that resulted in releases are still in use.
Some data gaps in this analysis are common to all risk analyses. For example, the need to
conduct analysis on a national scale and to consider a wide range of site conditions, facility
characteristics, and geographic settings dictates the use of generic, rather than site-specific modeling to
estimate exposures through the various pathways. Thus, the analysis of groundwater exposures relies
on probabilistically-defined dilution and attenuation values and the screening-level risk modeling uses
highly generic release, transport, and exposure models. This approach only roughly approximates
potential risks to humans and ecological receptors. Moreover, extensive professional judgment was
required to generalize from generic modeling for specific chemicals to broad classes of waste
constituents.
Another major source of uncertainty is associated with toxicity of the waste constituents. The
dose-response models and data used are the most current available to the Agency. Nevertheless,
substantial uncertainty exists regarding the probability and severity of adverse effects as a function of
dose for many chemicals. The use of a generically defined "chronic" exposure period may mask
important relationships between exposure periods and effects. Also, the Agency was not able to derive
any specific dose-response relationships for endocrine disrupters or for any non-additive combinations
of pollutant exposures. These uncertainties, unlike some of the others just discussed, are not likely to
be resolved in the near future.
Page 10-26
-------
10.3 Framework for Determining an Appropriate Course of Action
The U.S. Environmental Protection Agency will consider the appropriate course of action to
address significant gaps or potential gaps in the hazardous waste characteristics identified by the
Study. This section describes the framework that EPA plans to use in considering what course of
action is appropriate. As part of this process, the Agency will consider comments on the Study from
interested parties.
EPA's approach for considering a course of action will include two main steps:
Step 1: Identify the critical research needs and associated next steps necessary to analyze key
issues and fill major data deficiencies identified in the Scoping Study; and
Step 2: Identify and evaluate options to address the environmental management concerns
resulting from any gaps in the characteristics that were clearly identified in the
Scoping Study.
Both of these steps are described in more detail below.
10.3.1 Step 1: Identify Critical Research Needs and Next Steps Necessary to Analyze
Key Issues and Fill Major Data Deficiencies
The results of the Scoping Study vary greatly in terms of the certainty that can be attributed to
gaps in the hazardous waste characteristics. Some of the potential gaps, most notably certain
limitations in the ICR characteristics, are clearly identifiable problems. Most potential gaps, however,
are associated with considerable uncertainty that limits the degree to which conclusions can be made
about either the precise nature and extent of the gap or how, if at all, it should be addressed. Thus, a
critical activity in the near-term will be to assess what additional data and analysis are needed to
reduce uncertainty and better determine the significance of the most important potential gaps in the
characteristics identified by the Scoping Study.
10.3.2 Step 2: Identify and Evaluate Options to Address Any Clearly Identified Gaps
Some of the gaps identified in the Scoping Study are sufficiently defined that the Agency can
consider options for addressing the problem. Modifying an existing characteristic or developing a new
characteristic may be an appropriate method of filling some of these gaps. Other gaps may be better
addressed through other regulatory programs or in coordination with such programs. Thus, the list of
options that the Agency may consider include:
Specifying additional or revised test methods;
Expanding the definitions of existing characteristics;
Modifying the characteristics to reflect new risk data and modeling techniques;
Creating new characteristics, including contingent characteristics based on management
method or the type of generator or waste;
Identifying new hazardous waste listings or modifying existing listings;
Page 10-27
-------
Modifying other regulatory programs (e.g., Subtitle D);
Developing a non-regulatory approach (e.g., recycling, waste minimization); and
Promoting voluntary industry programs.
In evaluating a range of feasible options for particular gaps, the Agency will consider a variety
of factors including, but not necessarily limited to the following:
Affected industries, wastes, and management practices;
Human health and environmental benefits, such as reduced hazards and loadings of
hazardous constituents;
Compliance costs and difficulties; and
Implementation and administration costs and difficulties.
Evaluating options can be a highly complex and data-intensive activity. Thus, the Agency may be
unable to determine quickly that a particular approach is appropriate. Nevertheless, analyzing options
can help to narrow the range of feasible and appropriate actions and help to identify the critical issues
that need to be resolved in selecting an approach.
Page 10-28
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vvEPA
United States
Environmental Protection Agency
(5305W)
Washington, DC 20460
Official Business
Penalty for Private Use
$300
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