United States Office of Solid Waste EPA 530-R-99-019a
Environmental Protection Agency Washington, DC 20460 November 1999
svEPA Revised Risk Assessment for the
Air Characteristic Study
Volume I
Overview
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EPA530-R-99-193
November 1999
Revised Risk Assessment for the
Air Characteristic Study
Volume I
Overview
Office of Solid Waste
U.S. Environmental Protection Agency
Washington, DC 20460
Printed on Recycled Paper
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Table of Contents
Section Page
Executive Summary ES-1
1.0 Introduction 1-1
1.1 Purpose and Requirements of the Air Characteristic Study 1-1
1.2 Overview of Risk Assessment 1-2
1.3 Organization of Report 1-6
1.4 Companion Documents 1-6
2.0 Revisions to the Risk Assessment Framework 2-1
2.1 Source Characterization 2-1
2.1.1 Landfills 2-1
2.1.2 Land Application Units 2-2
2.1.3 Wastepiles 2-3
2.1.4 Tanks 2-3
2.2 Emissions Modeling 2-4
2.3 Air Dispersion Modeling 2-7
2.4 Human Health Benchmarks 2-10
2.5 Exposure and Risk Modeling 2-12
3.0 Summary of Risk Assessment Modeling Approach and Data Sources 3-1
3.1 Overview of Modeling Approach 3-1
3.2 Conducting the Analysis 3-5
3.2.1 Data Sources 3-10
3.2.2 Emissions Modeling 3-11
3.2.3 Dispersion Modeling 3-20
3.2.4 Exposure Modeling/Risk Estimation 3-23
3.3 Analysis of Variability and Uncertainty 3-33
3.3.1 Variability 3-33
3.3.2 Uncertainty 3-33
4.0 Summary of Risk Assessment Results 4-1
4.1 Overview of Results 4-1
4.2 Effect of Chemical Properties and Health Benchmarks 4-5
4.3 Effect of WMU Type 4-33
4.4 Effect of Exposure Factors 4-34
4.5 Subchronic and Acute Results 4-34
5.0 Characterization of Significant Findings 5-1
5.1 Introduction 5-1
5.2 Gaps in Constituent Coverage 5-2
5.2.1 RCRA Gaps in Constituent Coverage 5-2
5.2.2 Clean Air Act Gaps in Constituent Coverage 5-3
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Table of Contents (continued)
Section Page
5.2.3 Summary of Gaps in Regulation 5-4
5.3 Air Emission Controls Under RCRA 5-4
5.3.1 Air Emission Controls for Tanks Under RCRA 5-4
5.3.2 Air Emission Controls for Land Units Under RCRA 5-5
6.0 References 6-1
Appendix A - Comparison with LDR Universal Treatment Standards and Toxicity
Characteristic A-l
IV
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List of Figures
Figure Page
2-1 Cumulative tank distributions used in the current study 2-5
3-1 Conceptual diagram of a waste site 3-2
3-2 Model framework 3-6
3-3 Combination of results for individual WMUs into a distribution across all WMUs . . . 3-9
3-4 Meteorological station regions 3-12
4-1 Histogram of most protective 90/90 Cw for aerated treatment tanks 4-2
4-2 Histogram of most protective 90/90 Cw for nonaerated treatment tanks 4-2
4-3 Histogram of most protective 90/90 Cw for storage tanks 4-3
4-4 Histogram of most protective 90/90 Cw for landfills 4-3
4-5 Histogram of most protective 90/90 Cw for LAUs 4-4
4-5 Histogram of most protective 90/90 Cw for wastepiles 4-4
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List of Tables
Table Page
1-1 Constituents Modeled for All WMUs 1-3
1-2 Constituents Modeled for Tanks Only 1-5
2-1 Percentiles of New Tank Distributions Associated with Two Model Tanks 2-5
2-2 Chemical-specific Effects of Biodegradation Rate Correction 2-8
2-3 Summary of Issues and Changes for Inhalation Benchmarks Used in the Air
Characteristic Study 2-11
3-1 CHEMDAT8 Land-Based Unit Model Input Requirements 3-14
3-2 CHEMDAT8 Tank Model Input Requirements 3-15
3-3 Inhalation Health Benchmarks Used in the Air Characteristic Analysis 3-26
3-4 Summary of Variability and Uncertainty in the Study 3-34
4-1 Chronic 90/90 Cw at 25 m to 1,000 m, Risk = lO'VHQ = 1 for Landfills (mg/kg) .... 4-6
4-2 Chronic 90/90 Cw at 25 m to 1,000 m, Risk = 10'5/HQ = 1 for Land Application
Units (mg/kg) 4-10
4-3 Chronic 90/90 Cw at 25 m to 1,000 m, Risk = lO'VHQ = 1 for Wastepiles (mg/kg) . . 4-14
4-4 Chronic 90/90 Cw at 25 m to 1,000 m, Risk = lO'VHQ = 1 for Aerated Treatment
Tanks (mg/L) 4-18
4-5 Chronic 90/90 Cw at 25 m to 1,000 m, Risk = 10'5/HQ = 1 for Nonaerated
Treatment Tanks (mg/L) 4-23
4-6 Chronic 90/90 Cw at 25 m, Risk + lO'VHQ = 1 for Storage Tanks (mg/L) 4-27
4-7 Physical-Chemical Properties and Health Benchmarks 4-31
4-8 Most Limiting WMU Type 4-34
4-9 Acute and Subchronic 100/90 Cw at 25 to 75 m for HQ = 1 for Land
Application Units (mg/kg) 4-36
4-10 Acute and Subchronic 100/90 Cw at 25 to 75 m for HQ = 1 for
Wastepiles (mg/kg) 4-40
4-11 Comparison of Cw for Chronic, Subchronic, and Acute Averaging Times for
HQ = 1 for Land Application Units (mg/kg) 4-44
4-12 Comparison of Cw for Chronic, Subchronic, and Acute Averaging Times for
HQ = 1 for Wastepiles (mg/kg) 4-47
5-1 Regulatory, Occurrence, and Risk Comparison for TanksConstituents with
Waste Concentrations Less than 100 ppm 5-6
5-2 Regulatory, Occurrence, and Risk Comparison for Land-Based UnitsConstituents
with Waste Concentrations Less than 100 ppm 5-9
VI
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Volume I Executive Summary
Executive Summary
The U.S. Environmental Protection
Agency (EPA), Office of Solid Waste, has
analyzed the potential direct inhalation risks
that may result from unregulated emissions
from certain waste management units. This
document (Volume I) presents an overview of
the revised risk assessment for that analysis,
also referred to as the Revised Risk
Assessment for the Air Characteristic Study.
Volume II is the Technical Background
Document and Volume III (on CD-ROM)
presents results.
The Air Characteristic Study
This report and the 1998 Air
Characteristic Study are among the initial
steps for the EPA in fulfilling a long standing
goal to review the adequacy and
appropriateness of the hazardous waste
characteristics.
The first step for EPA in achieving this
goal was the Hazardous Waste Characteristic
Scoping Study (November 1996), in which
the Agency investigated potential gaps in the
characteristics. The Scoping Study identified
direct inhalation risks from emissions of
waste management units as one potential gap
in the Resource Conservation and Recovery
Act (RCRA) hazardous waste characteristics.
The Agency then completed the Air
Characteristic Study (May 1998) as the next
step in the process. The Air Characteristic
Study examined the potential direct inhalation
risks due to emissions from certain waste
management units. In accordance with
Agency policy, the technical work performed
for the 1998 Air Characteristic Study was
peer-reviewed. This report contains the
revised Air Characteristic Risk Assessment
based on peer-review and public comments.
Revised Risk Analysis
This study is a national analysis to
evaluate the possible need for an air
characteristic. As such, this study was
designed to highlight areas that may require a
more detailed review before any formalized
regulatory development work is initiated.
The overall goal of the risk analysis is to
estimate waste concentrations that could be
present in certain waste management units
(WMUs) and still be protective of human
health. Concentrations at specified risk levels
were estimated at six different distances for a
subset of constituents that could be present in
wastepiles, landfills, land application units,
storage tanks, and aerated and nonaerated
treatment tanks. The analysis is based on
modeling the emissions from a waste
management unit, transport through the
ambient environment, and exposure to a
receptor to backcalculate to a threshold
concentration in waste below which the risk to
human health would fall below a pre-
established threshold. To accomplish this, we
characterized waste sources, applied peer-
reviewed and commonly used emissions and
dispersion models, and established a Monte
Carlo analysis to capture variabilities in
receptor characteristics, such as exposure
parameters and location around a facility.
Chronic exposures were evaluated for 104 of
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Volume I
Executive Summary
the 105 constituents, and acute and
subchronic exposures were considered for 35
and 64 constituents, respectively. In addition,
protective concentrations in waste were
estimated for five receptor categories: an
adult resident, a child resident with exposure
starting between 0 and 3 years old, a child
resident with exposure starting between 4 and
10 years old, a child resident with exposure
starting between 11 and 18 years old, and an
off-site worker.
Distances of 25, 50, 75, 150, 500, and
1,000 meters were used as the basis for
backcalculated risk-based waste
concentrations. The resulting waste
concentrations were considerably higher for
receptors at the 500- and 1,000-m distances.
A sensitivity analysis conducted on the
dispersion component of this analysis
indicated that there is a sharp decline in air
concentration after the 150-m distance. The
25-m distance produces the lowest waste
concentrations but is also an unlikely
exposure scenario. The 50-, 75- and 150-m
results were very similar to each other (within
a factor of 2 to 3). This report displays results
for only the 25-, 150- and 1,000-m distances.
Results for the remaining distances are
provided in Volume III: Results.
Results of the risk analysis indicate that
the lowest estimated protective waste
concentrations (e.g., highest risk) were for the
aerated and nonaerated treatment tanks.
Aeration increases the potential for a chemical
to be emitted to the air, which results in a
higher emission rate per unit area for these
Note that one chemical of the original 105, 3,4-
dimethylphenol, was addressed, but risks could not
be quantified because data were insufficient to
develop a health benchmark.
tanks relative to the other units. Nonaerated
tanks are typically bigger than aerated tanks,
resulting in similar total emissions. In
general, the estimated protective waste
concentrations for treatment tanks were lower
than the other units by about an order of
magnitude or more. Following aerated and
nonaerated treatment tanks, the WMU ranking
was storage tanks, land application units,
landfills, and wastepiles.
Of the receptors evaluated, the protective
waste concentrations for adult residents were
lowest (i.e., highest risk), followed by the
child residents, from youngest to oldest. The
estimated waste concentrations for the offsite
worker were about an order of magnitude
higher than those for residents. The
differences in the results for the resident
scenarios can be attributed to the variation in
assumed exposure duration. The exposure
duration used in the risk modeling was
greatest for the adult, followed by the child
residents, and finally the off-site worker. For
the chronic exposures, it appeared that the
most important factor affecting the results was
the chemical's toxicity. The chemicals with
the lowest protective waste concentrations,
and so highest risk, were among the most
toxic.
No clear pattern emerged from the chronic,
subchronic, and acute results. Subchronic and
acute results may be lower or higher than
chronic results depending on the chemical,
and the difference ranges from negligible up to
2 orders of magnitude in either direction. The
most likely reason for this is that the hazard
posed by a chemical is likely to vary with
exposure duration, i.e., some chemicals have
greater hazard at chronic exposures; others at
acute and subchronic exposures.
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Volume I
Executive Summary
Integrating the Revised Risk Assessment
with the 1998 Analyses
In order to determine the need for an Air
Characteristic, the Agency conducted two
other analyses in 1998 along with the risk
assessment. These analyses on regulatory
coverage and constituent occurrence were to
ascertain the current management of the 105
constituents. Integrating the results from
these two analyses with the risk assessment
results would help the Agency identify the
nature and extent of gaps in regulatory
coverage and the significance of the resulting
human health risks.
This step was repeated for this task. The
results from the revised risk assessment were
combined with the results of the regulatory
gaps analysis and the occurrence analysis
from the 1998 Air Characteristic Study. This
comparison showed that 16 constituents were
neither associated with a listing nor on the
Toxicity Characteristic (TC) list under RCRA.
Two of these constituents had concentrations
in tanks less than 100 ppm. In addition, 2 of
these 16 constituents were not on the Clean
Air Act's hazardous air pollutants (HAPs) list.
Three constituents had estimated
protective waste concentrations lower than the
TC or TC-derived waste concentration. Two
constituents had TC levels that may not be
protective of air pathway risks for tanks, and
two constituents had waste concentrations
more stringent than TC levels for land-based
units. The magnitude of the difference
between the TC and the estimated air
characteristic waste concentrations (Cw) varied
according to the waste management unit and
the constituent.
Land disposal restrictions (LDRs) and the
protective concentrations in waste were
compared, and results indicated that the
treatment standards are not always below the
levels at which there are potential air risks.
Two constituents had concentrations in waste
for chronic exposures that were below the
LDR treatment levels. No constituents had
concentrations in waste that were below the
LDR treatment levels for acute or subchronic
exposures.
Next Steps
Should EPA decide this analysis identifies
constituents and waste management units of
potential significance as unregulated
emissions of possible concern, EPA has a
range of options. EPA could decide to further
study and potentially address these issues
through regulation under the CAA, RCRA, or
both. Further analysis would be needed before
any new regulatory action could be
promulgated.
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Volume I Section 1.0
1.0 Introduction
The U.S. Environmental Protection Agency (EPA), Office of Solid Waste (OSW), has
analyzed the potential risks to human health posed by the inhalation of vapor (gaseous) and
particulate (nongaseous) air emissions from a set of chemicals and metals when managed in
certain waste management units (WMUs). An analysis of these risks was initially performed in
1998 as part of the Air Characteristic Study (U.S. EPA, 1998a). In accordance with Agency
policy, the risk assessment conducted for the 1998 Air Characteristic Study was peer reviewed to
ensure that science was used credibly and appropriately in the work performed. Based on
comments made by the peer reviewers, EPA has revised the original risk assessment.
This report presents the revised risk assessment in three volumes. This document is
Volume I, the Overview. This volume provides a discussion of the changes made from the 1998
Air Characteristic Study, a general overview of the risk assessment, a summary of results of the
risk assessment, and the integration of the revised risk assessment results with the May 1998
regulatory gaps and occurrence analyses. A detailed description of the methodologies, data, and
supporting analyses used for the risk assessment may be found in Volume II, Revised Risk
Analysis for the Air Characteristic Study: Technical Background Document. The complete
results of the analysis are presented in Volume III, Revised Risk Analysis for the Air
Characteristic Study: Results (on CD-ROM).
1.1 Purpose and Requirements of the Air Characteristic Study
This report and the 1998 Air Characteristic Study are among the initial steps for EPA in
fulfilling a long-standing goal to review the adequacy and appropriateness of the hazardous waste
characteristics. The first step in achieving this goal was the Hazardous Waste Characteristic
Scoping Study (U.S. EPA, 1996), which the Agency completed November 15, 1996, under a
deadline negotiated with the Environmental Defense Fund. This study was conducted to identify
potential gaps in the current hazardous waste characteristics, as well as other modifications and
updates that are necessary to ensure that the definition of characteristics is complete, up-to-date,
and based on state-of-the-art methodologies. Based on the initial bounding analysis of potential
risks due to air emissions done as part of the Scoping Study, as well as follow-up analysis on
potential gaps in regulatory coverage under the Clean Air Act (CAA) and Subpart CC of the
Resource Conservation and Recovery Act (RCRA), OSW identified air emissions from WMUs
as one of the areas meriting further analysis.
The Air Characteristic Study addresses this area by examining the potential direct
inhalation risks due to emissions from certain WMUs. On May 15, 1998, in accordance with a
consent decree, EPA completed the first portion of the study. According to the consent decree
with EDF, a second part of the Air Characteristic Study, covering surface impoundments
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Volume I Section 1.0
receiving wastewaters that never exhibited a characteristic, will be completed March 26, 2001.
The purpose of the 1998 Air Characteristic Study, as outlined by the consent decree, was to
investigate gaps in the current hazardous waste characteristics and CAA programs. In addition,
resulting potential risks to human health posed by the inhalation of air emissions from wastes
managed in certain WMUs were to be investigated.
The 1998 Air Characteristic Study has three components: an evaluation of the coverage
and potential regulatory gaps in RCRA Subtitle C and the CAA, a risk analysis of air emissions
from WMUs, and an evaluation of the occurrence of these constituents in nonhazardous
industrial waste. The risk assessment component has undergone a peer review, and EPA has
made a number of changes to the risk assessment based on peer reviewer comments. In addition,
other revisions have been made based on public comments and improvements initiated by the
Agency. Since the other components of the May 1998 Air Characteristic Study have not been
revised, those analyses are not covered in this document. The original results of these analyses
are used in this report to present the significant findings from the integration of the revised risk
assessment results with the regulatory gaps and occurrence analyses.
1.2 Overview of Risk Assessment
The risk assessment described in this document is a national analysis designed to assess
the potential human health risk attributable to inhalation exposures when certain chemicals and
metals are managed as waste in certain types of WMUs. The purpose of the analysis is to
determine which chemicals and waste management units are of potential national concern purely
from a risk perspective; it is not intended to draw conclusions concerning regulatory coverage.
This information, combined with preliminary information on regulatory coverage and on the
presence of these chemicals in nonhazardous waste, will be useful in determining the need for
expanded regulatory coverage. Specifically, the purpose of this study is to provide technical
information on the potential risk from WMU emissions to help EPA determine the need to
expand regulatory coverage in the future.
The analysis presented in this report addresses specific chemicals that when managed as a
waste may pose a risk through direct inhalation exposures. Tables 1-1 and 1-2 list the chemicals
and metals included in this analysis. The analysis is structured so that the results of the risk
assessment are the concentrations of each constituent that can be present in each type of WMU
and still be protective of human health. The protective concentrations in waste were developed
for three types of receptors: adult residents, child residents, and workers. Three risk
endpoints chronic (over 1 year), subchronic (1 month), and acute (1 day)were evaluated.
The protective waste concentrations were estimated by modeling the emissions from a
waste management unit, the transport through the ambient environment, and the exposure to a
receptor to backcalculate a threshold concentration in a waste below which the risk to human
health would fall below a pre-established threshold. The waste management scenario modeled in
this analysis is storage, disposal, or treatment of industrial waste streams in RCRA subtitle D
WMUs.
1-2
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Volume I
Section 1.0
Table 1-1. Constituents Modeled for All WMUs
Constituent
CAS No.
Acetaldehyde [ethanal]
Acetone [2-propanone]
Acetonitrile [methyl cyanide]
Acrolein
Acrylonitrile
Allyl chloride
Arsenic
Barium
Benzene
Beryllium
Bromodichloromethane [dichlorobromomethane]
Bromoform [tribromomethane]
Bromomethane [methyl bromide]
1,3-Butadiene
Cadmium
Carbon disulfide
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane [dibromochloromethane]
Chloroform
Chloromethane [methyl chloride]
Chloroprene [2-chloro-1,3-butadiene]
Chromium VI
Cobalt
Cumene [isopropyl benzene]
Cyclohexanol
l,2-Dibromo-3-chloropropane
1,2-Dichlorobenzene [o-dichlorobenzene]
1,4-Dichlorobenzene [p-dichlorobenzene]
Dichlorodifluoromethane [CFC-12]
1,2-Dichloroethane [ethylene dichloride]
1,1-Dichloroethylene [vinylidene chloride]
1,2-Dichloropropane [propylene di chloride]
cis-1,3 -Di chl oropropy lene
trans-1,3 -Di chl oropropy 1 ene
1,4-Dioxane [1,4-diethyleneoxide]
Epichlorohydrin [l-chloro-2,3-epoxypropane]
1,2-Epoxybutane
2-Ethoxyethanol [ethylene glycol monoethyl ether]
2-Ethoxyethanol acetate [2-EEA]
Ethylbenzene
Ethylene dibromide [1,2-dibromoethane]
75-07-0
67-64-1
75-05-8
107-02-8
107-13-1
107-05-1
7440-38-2
7440-39-3
71-43-2
7440-41-7
75-27-4
75-25-2
74-83-9
106-99-0
7440-43-9
75-15-0
56-23-5
108-90-7
124-48-1
67-66-3
74-87-3
126-99-8
7440-47-3
7440-48-4
98-82-8
108-93-0
96-12-8
95-50-1
106-46-7
75-71-8
107-06-2
75-35-4
78-87-5
10061-01-5
10061-02-6
123-91-1
106-89-8
106-88-7
110-80-5
111-15-9
100-41-4
106-93-4
(continued)
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Volume I Section 1.0
Table 1-1. (continued)
Constituent CAS No.
Ethylene oxide 75-21-8
Formaldehyde 50-00-0
Furfural 98-01-1
Hexachloroethane 67-72-1
w-Hexane 110-54-3
Lead 7439-92-1
Manganese 7439-96-5
Mercury 7439-97-6
Methanol 67-56-1
2-Methoxyethanol 109-86-4
2-Methoxyethanol acetate [2-MEA] 110-49-6
Methyl tert-butyl ether 1634-04-4
Methylene chloride [dichloromethane] 75-09-2
Methyl ethyl ketone [2-butanone][MEK] 78-93-3
Methyl isobutyl ketone [hexone] [4-methyl-2-pentanone] 108-10-1
Methyl methacrylate 80-62-6
Naphthalene 91-20-3
Nickel 7440-02-0
2-Nitropropane 79-46-9
N-Nitrosodi-w-butylamine 924-16-3
N-Nitrosodiethylamine 55-18-5
N-Nitrosopyrrolidine 930-55-2
Propylene oxide 75-56-9
Pyridine 110-86-1
Styrene 100-42-5
1,1,1,2-Tetrachloroethane 63 0-20-6
1,1,2,2-Tetrachloroethane 79-34-5
Tetrachloroethylene [perchloroethylene] 127-18-4
Toluene 108-88-3
1,1,1 -Trichloroethane [methyl chloroform] 71-55-6
1,1,2-Trichloroethane [vinyl trichloride] 79-00-5
Trichloroethylene 79-01-6
Trichlorofluoromethane [trichloromonofluoromethane] 75-69-4
l,l,2-Trichloro-l,2,2-trifluoroethane [freon 113] 76-13-1
Triethylamine 121-44-8
Vanadium 7440-62-2
Vinyl acetate 108-05-4
Vinyl chloride 75-01-4
Xylenes, mixed isomers [xylenes, total] 1330-20-7
1-4
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Volume I Section 1.0
Table 1-2. Constituents Modeled for Tanks Only
Constituent CAS No.
Acrylamide 79-06-1
Acrylic acid 79-10-7
Aniline 62-53-3
Benzidine 92-87-5
Benzo(a)pyrene 50-32-8
2-Chlorophenol [o-chlorophenol] 95-57-8
Cresols, total 1319-77-3
7,12-Dimethylbenz[a]anthracene 57-97-6
N,N-Dimethyl formamide 68-12-2
3,4-Dimethylphenol 95-65-8
2,4-Dinitrotoluene 121-14-2
1,2-Diphenylhydrazine 122-66-7
Ethylene glycol 107-21-1
Hexachlorobenzene 118-74-1
Hexachloro-1,3-butadiene [hexachlorobutadiene] 87-68-3
Hexachlorocyclopentadiene 77-47-4
Isophorone 78-59-1
3-Methylcholanthrene 56-49-5
Nitrobenzene 98-95-3
Phenol 108-95-2
Phthalic anhydride 85-44-9
2,3,7,8-TCDD [2,3,7,8-tetrachlorodibenzo-^-dioxin] 1746-01-6
o-Toluidine 95-53-4
1,2,4-Trichlorobenzene 120-82-1
Emissions, transport, and exposure were modeled somewhat differently for the three risk
endpoints (chronic, subchronic, and acute). For emissions and transport, different averaging
times were used for each endpoint (1 year for chronic, 1 month for subchronic, and 1 day for
acute) to generate emission rates and dispersion factors. For exposure, subchronic and acute
exposures were modeled deterministically, using the point of maximum exposure at a specific
distance. Chronic exposures were modeled probabilistically using a Monte Carlo approach to
capture variation in receptor location and exposure factors. The WMUs assessed are aerated
treatment tanks, nonaerated treatment tanks, storage tanks, landfills, waste piles, and land
application units. The risk assessment was structured to capture national variations in
environmental settings. In addition, Monte Carlo analysis was used in the modeling to include
the variations in receptor characteristics such as exposure parameters and location around the
facility.
1-5
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Volume I Section 1.0
1.3 Organization of Report
The remainder of this report is organized as follows. Section 2 summarizes changes
made from the 1998 Air Characteristic Study. Section 3 provides a general overview of the risk
analysis. Section 4 presents the revised risk analysis results. Section 5 presents the integration of
the revised risk assessment results with the May 1998 regulatory gaps and occurrence analyses.
References are provided in Section 6, and supporting analyses are included in Appendix A.
1.4 Companion Documents
Volume II of this report, the Technical Background Document, provides a detailed
description of the methodologies, data, and supporting analyses used for the risk assessment.
Volume III of this report, Results (provided on CD-ROM), presents the detailed results of
the risk analysis.
1-6
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Volume I Section 2.0
2.0 Revisions to the Risk Assessment Framework
The analytical approach used for this analysis differs in important ways from the
approach used for the May 1998 Air Characteristic Study. Changes have been made to the risk
assessment to improve the robustness of the analysis, reduce uncertainty, and make corrections to
the 1998 study. The changes reflect comments made by peer-reviewers and public commenters
and other improvements made by the Agency. Several aspects of the Air Characteristic Study
risk assessment were modified, including source characterization, emissions modeling, air
dispersion modeling, health benchmarks, and exposure and risk modeling. These changes are
discussed in the following sections.
2.1 Source Characterization
Several changes were made to improve the source characterization. The source
characterization is the information about waste management unit (WMU) dimensions and
operations that defines how Industrial D waste is managed. It is important to accurately establish
these characteristics since they influence the rate of emissins and amount of dispersion of a
constituent.
Changes in source characterizations have affected all the WMU categories. These
changes are discussed for each WMU in the following sections. Except for tanks, source
characterizations were and still are based on the Subtitle D Survey (Schroeder et al., 1987);
however, the actual number of units included in the analysis from that survey has increased
slightly. Those increases are also discussed in the following sections.
2.1.1 Landfills
In both the May 1998 study and the current study, landfills were modeled assuming that
the landfill is divided into an equal number of cells. The cell size is determined by dividing the
total landfill area by the landfill life, 20 years, creating 20 cells for each landfill. One cell
operates for 1 year for the life of the landfill. Each cell is assumed to be covered at the end of the
year, preventing further emissions from that cell. Thus, emissions are only occurring from one
cell at any given time, or from an area equal to one-twentieth of the total area. Emissions from
the open cell are modeled as an emission rate per unit area (g/m2-s), and total emissions in g/s are
then calculated by multiplying this per-unit-area emission rate by the area from which emissions
occur. In the May 1998 study, the total area, instead of the cell area, was used to calculate total
emissions. This error has been corrected in the current study. This correction reduces total
emissions by a factor of 20 and air concentration (and therefore risk) by about a factor of 10
(because dispersion is not linear on source area). As a result of this change, the protective waste
concentrations for landfills are higher by about a factor of 10.
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Volume I Section 2.0
In the May 1998 study, 790 landfills were modeled from the Subtitle D survey data. This
reflected a total of 827 landfills reported, 37 of which were culled for various reasons. Eleven of
the 37 were culled based on results of previous groundwater modeling work by EPA not related
to the Air Characteristic Study. Those 11 sites are, however, relevant to the Air Characteristic
Study. Because retaining as many sites as possible is desirable, those 11 sites were included this
time, resulting in a database of 801 landfills for the current study. The culls made for the current
study are detailed in Volume II, Section 3.1.
2.1.2 Land Application Units
The Subtitle D survey does not provide data on application frequency for land application
units (LAUs). In the May 1998 study, application frequency was assumed to be four times per
year. Sensitivity analysis shows that the application frequency has a significant impact on
emissions even when total annual waste quantity is held constant: the more frequent the
applications, the greater the emissions. This is due in part to the fact that tilling is presumed to
occur whenever waste is applied, and tilling increases emissions by disturbing the waste.
Therefore, we reviewed several data sources in an effort to better characterize application
frequency for LAUs. These sources included Land Treatment Practices in the Petroleum
Industry (Environmental Research & Technology, 1983); Review and Evaluation of Current
Design and Management Practices for Land Treatment Units Receiving Petroleum Wastes
(Martin et al., 1986); and Handbook of Land Treatment Systems for Industrial and Municipal
Wastes (Reed and Crites, 1984). Data in these sources were used to establish a relationship
between the number of applications per year and the annual waste quantity managed. This
relationship was applied to the LAUs in the Subtitle D survey to establish a distribution of
application frequencies relevent to Industrial D LAUs. An application frequency of 24 times per
year was selected for use in this study, reflecting a central tendency value from the distribution
(see Volume II, Section 4.5.1 for more details).
The increase in application frequency from 4 applications per year to 24 applications per
year should increase emissions (and therefore risk) and decrease the protective waste
concentration.
In the May 1998 study, 308 land application units were modeled from the Subtitle D
survey data. This reflected a total of 354 land application units reported, 46 of which were culled
for various reasons. Thirty-seven of the sites culled were culled based on previous groundwater
modeling work by EPA not related to the Air Characteristic Study. Those 31 sites are relevant to
the Air Characteristic Study. Because retaining as many sites as possible is desirable, those sites
were included this time. Many of these sites had been culled because the reported waste quantity
and area implied an unrealistically large application rate (greater than 10,000 tons/acre/yr).
Those sites were retained in this study, and new waste quantities were imputed that did not
violate this criterion (see Volume II, Section 3.1.3 for more details). This resulted in a database
of 345 land application units for the current study. The culls made for the current study are
detailed in Volume II, Section 3.1.
2-2
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Volume I Section 2.0
2.1.3 Wastepiles
The Subtitle D survey does not provide data on wastepile height. In the May 1998 study,
wastepiles were modeled based on two assumed heights (2 and 5 meters). However, wastepile
height is related to wastepile area, waste quantity, and retention time. Therefore, it is more
realistic to evaluate the characteristics of each wastepile and assign a height individually.
Wastepile area and waste quantity are reported in the Subtitle D survey, but retention time is not.
Therefore, to tailor the wastepile heights to known data, a relationship between wastepile area,
waste quantity, and height was developed (see Volume II, Section 3.1.1 for more details). In this
study, each wastepile modeled was assigned a height based on that relationship. Height is used
only in the dispersion modeling and affects air concentration; the greater the height, the greater
the dispersion, and so the lower the air concentration at a particular location. The dispersion
model is not sensitive to small changes in height; therefore, to simplify dispersion modeling
without sacrificing accuracy, a set of six discrete heights, covering the range of heights calculated
for all the wastepiles, was used. These heights were 1, 2, 4, 6, 8, and 10 meters.
Approximately 77 percent of the wastepiles modeled were assigned a height of 1 m, and
95 percent of the wastepiles were assigned a height of 4 m or less. Therefore, most of the
wastepiles are modeled at a lower height in the current study than in the May 1998 study. As a
result, air concentration (and therefore risk) will tend to be greater and the protective waste
concentration lower. This difference is significant: about a factor of 2 to 10 relative to the 2-m
wastepiles in the May 1998 study and a factor of 2 to 25 relative to the 5-m wastepiles in the May
1998 study.
In the 1998 study, 742 wastepiles were modeled from the Subtitle D survey data. This
reflected a total of 853 wastepiles reported, of which 111 were culled for various reasons (most
because they are Bevill facilities, which are exempt from Subtitle C regulation and would
therefore never be subject to an Air Characteristic under Subtitle C). Three of the sites culled
were culled based on previous groundwater modeling work by EPA not related to the Air
Characteristic Study. Those three sites are relevant to the Air Characteristic Study. Because
retaining as many sites as possible is desirable, those three sites were included this time, resulting
in a database of 745 wastepiles for the current study. The culls made for the current study are
detailed in Volume II, Section 3.1.
2.1.4 Tanks
The tank source category has been revised extensively, with respect to both how tanks are
characterized and the categories of tanks modeled.
Because the Subtitle D survey did not contain data on tanks, they were characterized in
the May 1998 study using two model tanks placed at 29 locations. A full distribution of tanks,
using a database of many actual tank facilities (as was done for the other WMUs), would provide
a more representative result. However, data on Industrial D tanks do not exist; therefore, in the
current study, tanks were characterized using tank data from the 1986 National Survey of
Hazardous Waste Treatment, Storage, Disposal, and Recycling Facilities (TSDR) Database (U.S.
EPA, 1987) (see Volume II, Section 3.4 for more details). These data provide a distribution of
tanks to represent the range of tank configurations used in the United States. This is an important
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Volume I Section 2.0
step in improving the analysis because some tank characteristics are critical parameters in the
emissions modeling. However, the TSDR tank database did not include data on all parameters
needed for the emission and dispersion modeling; therefore, data from site visits to tanks done by
the Agency in 1985 and 1986 in support of the development of RCRA Air Emission Standards
were used to develop some of the tank-specific parameter values to characterize tank engineering
and operating parameters (see Volume II, Section 3.4.2 for more details). This introduces some
uncertainty into the tank characterization; however, we believe this uncertainty to be less than the
uncertainy arising from the use of only two model tanks to characterize the universe of Industrial
D tanks.
In the May 1998 study, four categories of tanks were modeled: aerated tanks with and
without biodegradation and storage tanks with and without biodegradation. These categories do
not capture nonaerated treatment tanks. Based on the TSDR tank data, nonaerated treatment
tanks appear to differ from storage tanks (which are also nonaerated) in important ways,
particularly with respect to the distribution of area. In addition, storage tanks are not designed
for biodegradation, so the category of storage tank with biodegradation is not representative of
real tanks. The tank categories modeled in the current study include aerated treatment tanks,
nonaerated treatment tanks, and storage tanks. Some of the aerated treatment tanks were
modeled with biodegradation, while others were modeled without biodegradation, depending on
the treatment process reported. Nonaerated treatment tanks, like storage tanks, are typically not
optimized for biodegradation; therefore, both nonaerated treatment tanks and storage tanks were
modeled with no biodegradation.
Figure 2-1 shows the distribution of area for the three tank categories modeled in this
study and shows where the two model tanks used in the 1998 study fall relative to those
distributions. Table 2-1 shows exactly where the two model tanks fall in the new tank
distributions. Because the two model tanks both fall relatively high in the new distributions, the
use of the new distributions will tend to decrease tank size (and therefore risk) and increase the
90th percentile protective waste concentration. The elimination of biodegradation from many of
the tanks will increase emissions (and therefore risk) and tend to decrease the protective waste
concentration relative to tank types with biodegradation from the 1998 study.
2.2 Emissions Modeling
Changes in emissions modeling have affected all of the land-based WMUs. Tank
emissions modeling was not changed; the new distribution of tanks is modeled in the same
manner as in the May 1998 study with regard to emissions estimates. Changes in emissions
modeling for land-based units were considered for both volatile and particulate emissions.
For particulate emissions, most of the parameter values used to compute particulate
emission rates are site-specific. Some vary with the waste (e.g., silt content of the waste), others
with the waste management unit (e.g., roughness height of unit, vegetative cover on unit), and
still others with the location of the unit (e.g., meteorological parameters like precipitation data
and windspeed). The 1998 study did account for the variability of the meteorological parameters
by varying these based on assigned location of the unit; however, variability in the other
parameters was not captured. For the current study, consideration was given to developing
distributions of the other parameter values in the particulate emissions model for use in the
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Volume I
Section 2.0
100% T
90% -
0%
10
100
1000
10000
Area(rrf)
Figure 2-1. Cumulative tank distributions used in the current study.
Table 2-1. Percentiles of New Tank Distributions Associated with Two Model Tanks
Type of Tank
Aerated treatment
Nonaerated treatment
Storage
Percent of new tanks that are
Small model tank (27 m2)
73%
66%
86%
smaller than the model
Large model tank
97%
93%
100%
tank:
(430 m2)
2-5
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Volume I Section 2.0
Monte Carlo model, in order to capture variability in the protective waste concentration due to
variation in these parameters and to provide a more complete description of the variability of the
protective waste concentrations. However, no data were identified that would support
development of distributions, so no change was made to the particulate emissions modeling. The
exclusion of such distributions only affects the distribution of results for metals; particulate
emissions for volatile constituents are trivial compared to volatile emissions, so such a
refinement would not have a significant effect on the results for volatile constituents.
Modeling of volatile emissions from all land-based units was modified with respect to the
treatment of adsorbtion. Adsorption/absorption is the tendency of a chemical or liquid media to
attach or bind to the surface or fill the pores of particles in the soil or waste and therefore not
volatilize into the air. This tendency of a chemical to adsorb to or absorb in particles is important
to consider in estimating the concentration of the chemical on particles emitted to the air due to
wind erosion. The CHEMDAT8 model estimates emissions from land-based WMUs using a
simple emissions model that accounts for contaminant partitioning between a liquid waste matrix
and the air, diffusion of vapors through a porous media, and contaminant loss through
biodegradation. This model accounts for adsorbtion when the waste concentration entered is a
liquid-phase concentration; however, it does not account for adsorbtion when a total waste
concentration (i.e., liquid and solid phase) is entered. The assumption of an entered waste
concentration in liquid phase was based on the petroleum wastes for which CHEMDAT8 was
originally developed and may not apply to the chemicals considered in this analysis. Therefore, a
method for including adsorptive partitioning for total waste concentrations was developed and
used to modify CHEMDAT8 for the current study. The changes to the CHEMDAT8 code are
shown in detail in Section 4.3 of Volume II. This change should tend to decrease emissions and
risk and increase protective waste concentration; the extent of the decrease in emissions will be
constituent-specific, depending on the constituent's tendency to adsorb to particles.
The LAU emissions model was changed substantially. Instead of quarterly
meteorological data, which were used in the May 1998 study, monthly meteorological data were
used. Monthly meteorological data are more consistent with the application rate used in this
study (24 applications per year). In addition, changes were made to the approach for estimating
long term emission rates for LAUs in the current study. The May 1998 version of the model used
steady state assumptions to estimate long-term emission rates. This presumed that all chemicals
reached steady state emissions immediately (i.e., concentration remaining in the unit remains
constant over time because waste additions and losses balance each other). While most
chemicals will reach steady state within 1 or 2 years, some chemicals take longer than that or
may never reach steady state. In order to better address the time to reach steady state in the
current study, emissions were estimated using a pseudo-steady state approach, in which a series
of steady state solutions was calculated for many short time periods, and the resulting emission
rates were averaged to estimate long-term emissions. Specifically, emissions were estimated on
a monthly basis for 40 years, and monthly emission rates for year 40 were averaged to estimate
long-term annual emission rates. The actual length of time to reach steady state is constituent-
specific. Forty years was chosen as a sufficiently long time for all chemicals that would ever
reach steady state to do so. For those constituents that reach steady state sooner, there is no
difference between using the first year after steady state is reached (typically year 2 or 3) and year
40. However, for constituents that do take many years to reach steady state, this approach
provides a more realistic estimate of emissions.
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Volume I Section 2.0
An error in soil biodegradation rates that affects chronic, subchronic, and acute volatile
emission rates for LAUs and chronic volatile emissions for wastepiles was identified and
corrected for the current study (the differences between chronic, subchronic, and acute are
discussed in Section 3.1). In the May 1998 study, the soil biodegradation rates were erroneously
labeled as half lives and therefore used incorrectly. While half life is related to the first-order
biodegradation rate, the two are not interchangeable. When this error was discovered, all soil
biodegradation rates were verified against the original data source (Howard et al., 1991). The
current study correctly uses the verified biodegradation rates from Howard et al. (1991). The
impact of this error is chemical-specific. Table 2-2 summarizes the direction of the error for the
chemicals modeled in land-based units. For about half of these, the biodegradation rate was too
low, resulting in an overestimate of emissions. Emissions modeled with the correct
biodegradation rate will be lower, resulting in less risk and a higher protective waste
concentration. Most of the remaining chemicals were relatively unaffected by this correction.
For only one chemical was the incorrect biodegradation rate too high, resulting in an
underestimate of emissions. The corrected emissions for this chemical will be higher, resulting
in more risk and a lower protective waste concentration.
2.3 Air Dispersion Modeling
Several changes in dispersion modeling were implemented in the current study and make
the dispersion modeling more accurate than in the May 1998 study.
In the May 1998 study, wet and dry depletion of the atmospheric concentrations (plume
depletion) of vapors and particulates were not considered due to the great increase in run time of
ISCST3 for area sources when depletion is modeled (run times with depletion for area sources
are typically 15 to 30 times longer than run times without depletion) and the short timeframe for
completing the study. However, plume depletion can have a significant effect on air
concentration, especially for parti culates, and many of the peer-review comments identified this
as a serious shortcoming of the May 1998 study. Therefore, for this analysis, with more time
available, the issue of depletion was revisited. In addition, since May 1998, it had come to light
for other EPA work (the Hazardous Waste Identification Rule, or HWIR) that the precipitation
data in the hourly meteorological data used in the dispersion model were incomplete (i.e., some
hours had missing precipitation data, resulting in total precipitation less than actual
precipitation), which could affect the amount of wet depletion occurring. Work had already been
done for the HWIR project to interpolate missing precipitation data for many of the
meteorological locations modeled in the Air Characteristic Study.
Several sensitivity analyses were conducted to assess the importance of wet and dry
depletion for particulates and wet depletion for vapors (ISCST3 cannot model dry depletion of
vapors; therefore, this could not be considered. However, dry depletion of vapors is expected to
be negligible). These sensitivity analyses showed that for both vapors and particulates, wet
depletion did not have a significant impact on air concentrations (differences were less than
2 percent), even using the more complete interpolated precipitation data developed for HWIR.
Dry depletion of particulates, on the other hand, did have a significant effect on air concentration
(differences ranged up to about 40 percent). Therefore, dry depletion of particles was included in
the current study for all land-based units. This change will reduce the air concentration of
2-7
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Volume I
Section 2.0
Table 2-2. Chemical-specific Effects of Biodegradation Rate Correction
CAS Chemical
New soil
biodegradation rate
(sec-1)
Old soil
biodegradation rate
(sec-1)
Higher emissions, lower Cw
78875 Dichloropropane, 1,2-
6.2E-09
1.1E-07
Lower emissions, higher Cw
75070 Acetaldehyde
67641 Acetone
75058 Acetonitrile
107028 Acrolein
107131 Acrylonitrile
107051 Allyl chloride
71432 Benzene
75274 Bromodichloromethane
106990 Butadiene, 1,3-
67663 Chloroform
98828 Cumene
108930 Cyclohexanol
106467 Dichlorobenzene, p-
10061015 Dichloropropylene, cis-1,3-
10061026 Dichloropropylene, trans-1,3-
106898 Epichlorohydrin
106887 Epoxybutane, 1,2-
1 1 1 1 59 Ethoxyethanol acetate, 2-
110805 Ethoxyethanol, 2-
100414 Ethylbenzene
75218 Ethylene oxide
50000 Formaldehyde
67561 Methanol
1 1 0496 Methoxyethanol acetate, 2-
109864 Methoxyethanol, 2-
74839 Methyl bromide
74873 Methyl chloride
78933 Methyl ethyl ketone
108101 Methyl isobutyl ketone
80626 Methyl methacrylate
1634044 Methyl tert-butyl ether
75092 Methylene chloride
91203 Naphthalene
110543 n-Hexane
924163 N-Nitrosodi-n-butylamine
75569 Propylene oxide
110861 Pyridine
100425 Styrene
630206 Tetrachloroethane, 1,1,1,2-
79345 Tetrachloroethane, 1,1,2,2-
108883 Toluene
1.1E-06
1.1E-06
2.9E-07
2.9E-07
3.5E-07
5.7E-07
5.0E-07
4.5E-08
2.9E-07
4.5E-08
1.0E-06
4.5E-08
4.5E-08
7.1E-07
7.1E-07
2.9E-07
6.2E-07
2.9E-07
2.9E-07
8.0E-07
6.8E-07
1.1E-06
1.1E-06
2.9E-07
2.9E-07
2.9E-07
2.9E-07
1.1E-06
1.1E-06
2.9E-07
4.5E-08
2.9E-07
1.7E-07
5.0E-07
4.5E-08
6.5E-07
1.1E-06
2.9E-07
1.8E-07
1.8E-07
3.6E-07
1E-20
6.1E-10
2.4E-09
2.4E-09
2.0E-09
1.2E-09
1.4E-09
1E-20
1E-20
2.4E-09
7.0E-10
1E-20
1E-20
9.8E-10
9.8E-10
2.4E-09
1E-20
1E-20
2.4E-09
8.7E-10
1E-20
6.1E-10
6.1E-10
1E-20
1E-20
2.4E-09
2.4E-09
6.1E-10
6.1E-10
2.4E-09
1E-20
2.4E-09
4.2E-09
1E-20
1E-20
1E-20
6.1E-10
2.4E-09
5.8E-09
3.8E-09
1.9E-09
(continued)
2-8
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Volume I
Section 2.0
CAS
76131
108054
1330207
Table 2-2.
Chemical
Trichloro-1 ,2,2-trifluoroethane, 1,1,2-
Vinyl acetate
Xylenes
(continued)
New soil
biodegradation rate
(sec-1)
2.2E-08
1.1E-06
2.9E-07
Old soil
biodegradation rate
(sec-1)
1E-20
1E-20
2.4E-09
Relatively unaffected
7440382
7440393
7440417
7440439
75150
56235
108907
124481
126998
7440473
7440484
96128
95501
75718
107062
75354
123911
106934
98011
67721
7439921
7439965
7439976
7440020
79469
55185
930552
127184
75252
71556
79005
79016
75694
121448
7440622
75014
Arsenic
Barium
Beryllium
Cadmium
Carbon disulfide
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane
Chloroprene
Chromium (total)
Cobalt
Dibromo-3-chloropropane, 1,2-
Dichlorobenzene, o-
Dichlorodifluoromethane
Dichloroethane, 1,2-
Dichloroethylene, 1,1-
Dioxane, 1,4-
Ethylene dibromide
Furfural
Hexachloroethane
Lead
Manganese
Mercury
Nickel
Nitropropane, 2-
N-Nitrosodiethylamine
N-Nitrosopyrrolidine
Tetrachloroethylene
Tribromomethane
Trichloroethane, 1,1,1-
Trichloroethane, 1,1,2-
Trichloroethylene
Trichlorofluoromethane
Triethylamine
Vanadium
Vinyl chloride
0
0
0
0
0
2.2E-08
5.3E-08
4.5E-08
4.5E-08
0
0
4.5E-08
4.5E-08
4.5E-08
4.5E-08
4.5E-08
4.5E-08
4.5E-08
0
4.5E-08
0
0
0
0
4.5E-08
4.5E-08
4.5E-08
2.2E-08
4.5E-08
2.9E-08
2.2E-08
2.2E-08
2.2E-08
0
0
4.5E-08
1E-20
1E-20
1E-20
1E-20
1E-20
3.1E-08
1.3E-08
1.6E-08
1.6E-08
1E-20
1E-20
1.6E-08
1.6E-08
1.6E-08
1.6E-08
1.6E-08
1.6E-08
1.6E-08
1E-20
1.6E-08
1E-20
1E-20
1E-20
1E-20
1.6E-08
1.6E-08
1.6E-08
3.1E-08
1.6E-08
2.4E-08
3.2E-08
3.1E-08
3.1E-08
1E-20
1E-20
1.6E-08
2-9
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Volume I Section 2.0
particulates, reducing risk and increasing the protective waste concentration for land-based units.
The change is only significant for metals, however, because particulate emissions of volatile
constituents are negligible compared to volatile emissions.
As discussed earlier, several changes to the source characterization were made that
required new dispersion modeling. These changes included the addition of more specific heights
for wastepiles and the recharacterization of tanks.
Dispersion modeling for wastepiles was modified to better capture the effect of wastepile
height on ground-level concentrations. Section 2.1.3 discusses these changes. The difference in
the results is significantabout a factor of 2 to 10 relative to the 2-m wastepiles in the May 1998
study and a factor of 2 to 25 relative to the 5-m wastepiles in the May 1998 study.
Dispersion modeling for tanks was also modified to capture the range of area/height
combinations reflected in the new tank characterizations. A total of 33 area/height combinations
were modeled for tanks, compared to only 2 area/height combinations (corresponding to the two
model tanks) in the May 1998 study. The overall effect of the new area-height combinations
compared to the ones used last year is not clearly in one direction, as the effect of the change in
areas has effects in the opposite direction of the effect of the change in heights. As shown in
Figure 2-1, the two model tanks used in the May 1998 study fall fairly high on the distribution of
tanks used in the current study. Therefore, many of the tanks modeled in the current study are
smaller in area, which will tend to result in lower air concentrations, lower risk, and higher
protective waste concentrations relative to the May 1998 study. However, the two heights
modeled in the May 1998 study were also high relative to the distribution of heights modeled in
the current study, which has the opposite effect: the generally lower heights will tend to increase
air concentration and risk, and lower protective waste concentration.
Finally, an error in the interpolation of dispersion coefficients for wastepiles in the May
1998 study was discovered and corrected for the current study. In the May 1998 study, the areas
used for the interpolation were those for tanks, not wastepiles, which resulted in interpolated
UACs (and therefore air concentration and risk) that are too low by a factor of 2 to 3.
2.4 Human Health Benchmarks
Twenty-eight of the inhalation benchmarks used in the May 1998 study have been
changed. The changes are summarized in Table 2-3. More detailed information is available in
Volume II, Section 6.0.
In some cases, new IRIS or other published information became available during the past
year that suggested a change in the inhalation benchmark for this study.
The progression of values from chronic to subchronic to acute benchmarks was also
reviewed, especially when the chronic value exceeded the subchronic or acute value. The
anticipated progression would reflect that high concentrations of a chemical can be tolerated
without ill effect for shorter periods of exposure than for longer periods of exposure. Therefore,
2-10
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Volume I
Section 2.0
Table 2-3. Summary of Issues and Changes for Inhalation Benchmarks
Used in the Air Characteristic Study
CAS
75-05-8
7440-38-2
75-15-0
7440-47-3
1319-77-3
108-93-0
106-46-7
107-06-2
123-91-1
106-89-8
111-15-9
110-80-5
78-59-1
7439-97-6
67-56-1
109-86-4
78-93-3
75-09-2
91-20-3
7440-02-0
108-95-2
75-56-9
100-42-5
1746-01-6
127-18-4
108-88-3
Name
Acetonitrile
Arsenic
Carbon disulfide
Chromium VI
Cresols (total)
Cyclohexanol
Dichlorobenzene, 1,4-
Dichloroethane, 1,2-
Dioxane, 1,4-
Epichlorohydrin
Ethoxyethanol acetate, 2-
Ethoxyethanol, 2-
Isophorone
Mercury
Methanol
Methoxyethanol, 2-
Methyl ethyl ketone
Methylene chloride
Naphthalene
Nickel
Phenol
Propylene oxide
Styrene
TCDD, 2,3,7,8-
Tetrachloroethylene
Toluene
Issue
New IRIS RfC=0.06 mg/m3, appropriate to
use as subchronic
CaEPA acute REL updated
Chronic RfC target organ should be
neurological; CalEPA acute REL updated
New IRIS RfC= 1E-4 mg/m3 (particulates);
revised intermediate MRL= 5E-4 mg/m3
(particulates)
Received public comment on chronic RfC;
subchronic lower than chronic (due to
calculation error)
New FR RfC=2E-5 mg/m3
Chronic RfC target organ should be liver
Acute RfC lower than subchronic
Acute RfC lower than subchronic; CalEPA
acute REL updated
CalEPA acute REL updated
CalEPA acute REL updated
Acute RfC lower than subchronic; CalEPA
acute REL updated; chronic RfC target organ
should be male reproductive and
hematological
New FR RfC= 1 .2E-2 mg/m3
CalEPA acute REL updated
CalEPA acute REL updated
Acute RfC lower than subchronic; CalEPA
acute REL updated
CalEPA acute REL updated
Revised acute MRL= 3 ppm (10 mg/m3)
New IRIS RfC= 3E-3 mg/m3
CalEPA acute REL updated
Public comment on chronic RfC; new FR
RfC=6E-3 mg/m3; CaEPA acute REL
updated
CaEPA acute REL updated
CaEPA acute REL updated
URF available (3.3E+1 per |ig/m3) in LEAST
Acute RfC lower than subchronic; cancer
benchmarks available - Superfund URF
(5.8E-7 per |ig/m3) and CSF (2E-3 per
mg/kg/d)
Revised acute MRL = 4 ppm (15 mg/m3)
Resolution
Revise chronic and subchronic RfCs
Revise acute RfC
Revise chronic RfC target organ and
acute RfC
Revise chronic and subchronic RfCs
No revision on chronic RfC; revise
subchronic RfC (1.2E-3 mg/m3)
Revise chronic RfC; recalculate
subchronic (2E-4 mg/m3)
Revise chronic RfC target organ
Revise subchronic RfC (acute MRL =
chronic MRL, therefore should also =
subchronic = 0.81 mg/m3)
Update acute RfC (still incorrect
progression - see text)
Revise acute RfC
Revise acute RfC
Update acute RfC (still incorrect
progression - see text); revise chronic
RfC target organ
Revise chronic RfC; recalculate
subchronic (1.2E-1 mg/m3)
Revise acute RfC
Revise acute RfC
Update acute RfC (still incorrect
progression - see text)
Revise acute RfC
Revise acute RfC
Revise chronic RfC; recalculate
subchronic RfC (3E-2 mg/m3)
Revise acute RfC
Revise chronic RfC as per FR;
recalculate subchronic RfC (6E-2
mg/m3); revise acute RfC
Revise acute RfC
Revise acute RfC
Add URF
No revision of acute RfC; revise URF &
CSF
Revise acute RfC
(continued)
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Table 2-3. (continued)
CAS
7440-62-2
1330-20-7
Name
Vanadium
Xylenes (total)
Issue
Public comment on chronic RfC; acute RfC
lower than subchronic
Calculation error for chronic RfC
Resolution
Revise subchronic RfC (subchronic =
chronic = 7E-5 mg/m3); recalculate acute
(7E-4 mg/m3)
Revise chronic RfC (4E-1 mg/m3)
CSF = cancer slope factor
FR = Federal Register
MRL = minimal risk level
REL = reference exposure level
RfC = reference concentration
URF = unit risk factor
chronic noncarcinogenic benchmarks should be lower than subchronic benchmarks, and
subchronic benchmarks should be lower than acute benchmarks (note that for chronic
benchmarks, this comparison can only be meaningfully made for noncarcinogens, since the
chronic carcinogenic slope factor cannot be directly compared to a subchronic or acute
benchmark). This review resulted in some modifications; however, data were not available to
correct all instances in which the progression from chronic to subchronic to acute was not as
expected. Subchronic and acute benchmarks are typically obtained from different sources and
based on different underlying studies than chronic benchmarks are. Inconsistencies in how the
benchmarks were developed or the underlying studies used often accounts for the discrepancy in
expected progression. In many cases, no set of benchmarks could be found that displayed the
expected progression.
Finally, public commenters on the May 1998 study specifically identified benchmarks for
four constituents that should be reviewed: cobalt, cresols, phenol, and vanadium. These reviews
resulted in changes as well.
In addition to changes in the basic health benchmarks described above, a change was
made in how the cancer slope factors were used for children. Slope factors are developed for
adults, using an assumed body weight of 70 kg. In the May 1998 study, slope factors were
adjusted for children based on actual body weight. However, based on peer-review comments
and further discussion with Agency experts in cancer dose-response, this adjustment has been
eliminated from the current study. Cancer slope factors are used as presented for children,
without adjustment. It should be noted, however, that the differences between an adult's and a
child's physiology are accounted for in this study by adjusting the appropriate exposure factors.
This is discussed in the following section.
2.5 Exposure and Risk Modeling
Four changes were made to the exposure and risk model used in this analyis:
# Update of the exposure factor distributions
# New child exposure approach
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# Change in worker scenarios
# Change in checks for nonlinear!ty.
Exposure factors used in this study include body weight, inhalation rate, and exposure
duration. Distributions of these exposure factors were updated from those used in the May 1998
study. Previously, data for males were used. However, this does not account for differences
between males and females. Males typically have higher body weights and inhalation rates than
females, as well as higher inhalation rates per unit of body weight. For this update, data on both
males and females were used to better capture the potential effects on the whole population, not
just males. Because females have a lower inhalation rate per unit of body weight than males, the
effect should be to lower the overall distribution of risk and increase the protective waste
concentration.
Three child age groups, or cohorts, were used to model child exposures: 0 to 3, 4 to 10,
and 11 to 18 years of age. These cohorts are unchanged from the May 1998 study and reflect the
age cohorts for which inhalation rate data are available. In the May 1998 study, the results were
presented as a single "child" receptor. For each iteration of the Monte Carlo analysis, a starting
age for exposure was chosen at random from among 0, 4, and 11 years (the three cohort starting
ages), with the probability of each of the three starting ages being chosen proportional to the total
number of years in the cohort. A single exposure duration was associated with each of the three
starting ages, based on the median for that age cohort, and this was not varied for a particular
starting age. None of the three exposure durations, when coupled with their associated starting
age, resulted in exposure past age 18. This approach does not fully capture the impact of
different starting ages (since these were restricted to three) or the full variability of exposure
duration.
For this study, the child exposure approach was modified to better capture variations in
age at start of exposure and exposure duration. Results were calculated and saved separately for
receptors falling into each of the three age cohorts at the start of exposure (note that exposure
may last longer than just the range of ages in a cohort); these are presented as "child 0-3 years,"
"child 4-10 years," and "child 11-18 years." For each iteration for a cohort, exposure begins at a
starting age selected at random within the cohort (with each year of age within the cohort having
equal probability of being selected). An exposure duration is also selected at random for each
iteration from a distribution for the cohort (so there are three exposure duration distributions, one
per cohort). Exposure is then started at the selected starting age and continues through
succeeding age cohorts as necessary until the exposure duration selected for that starting age is
reached. Depending on the starting age and exposure duration selected, exposure may continue
into adulthood.
Both on-site workers and off-site workers were included in the May 1998 study. For this
study, the on-site workers are no longer included in the receptors modeled. Accordingly, because
concentration at 0 m from the WMU was only used for the on-site worker scenario, it has been
dropped. Off-site workers have been retained and are evaluated for all receptor locations, as
before.
A units conversion error in the calculation of a hazard quotient for lead was identified in
the May 1998 model and corrected for this study. Specifically, a units conversion factor to
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convert air concentration from |ig/m3 to mg/m3 was omitted. As a result, the hazard quotients for
lead were too high by a factor of 1,000 and the protective waste concentrations too low by the
same amount. Due to the modeling of different receptors for lead (children age 0 to 3 years and 3
to 7 years), the hazard quotient equation for lead was separate from the equation used for all
other chemicals, so this error did not affect any other chemicals.
Finally, the approach to adjusting the results for nonlinearities in the emissions modeled
has been changed. In the May 1998 study, two types of adjustments were made that have been
dropped for the current study. These are discussed below.
# In the May 1998 study, waste concentrations were backcalculated using both an
aqueous-phase emission rate (modeled using Henry's law) and an organic-phase
emission rate (modeled using Raoult's law). Typically, the aqueous-phase
emission rates are much higher than the organic-phase emissions rates, resulting
in lower waste concentrations based on aqueous-phase emission rates, but for a
few chemicals that was not the case. In those cases, the backcalculated
concentration was adjusted in the May 1998 study to be based on the organic-
phase emission rate. However, the fact that greater emissions occur from the
organic phase does not alter the fact that the aqueous phase is a far more likely
scenario for the waste management units modeled in this study. The Agency
decided that this adjustment was unnecessarily worst-case; therefore, this
adjustment was dropped in the current study, and all results are based on the
aqueous-phase emission rates. Results that would be lower if based on the
organic-phase emission rates are footnoted.
# In the May 1998 study, the backcalculated waste concentration based on the
aqueous-phase emission rate was compared to either the soil saturation
concentration (for land-based units) or the solubility at neutral pH and a
temperature of 20-25 °C. These are the theoretical maximum concentrations at
which aqueous phase wastes can exist; at higher concentrations, the waste is
organic phase. If the backcalculated waste concentration based on aqueous-phase
emission rates exceeded the soil saturation concentration or solubility, then it was
adjusted to be based on the organic-phase emission rate instead. However, the
soil saturation concentration and solubility are both dependent on site- and waste-
specific conditions such as temperature and pH. Therefore, a backcalculated
waste concentration near the soil saturation concentration or solubility calculated
for this study may be possible in some situations and not in others. Rather than
artificially restrict the results to standard conditions, in the current study all results
are based on the aqueous-phase emission rates. If this backcalculated
concentration exceeds the soil saturation concentration or solubility calculated for
this study, the result is footnoted, and the footnote identifies whether pure
organic-phase component (i.e., 1 million ppm modeled as organic phase) results in
a risk greater or less than the cutoff risk of 10"5 or the cutoff HQ of 1.
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3.0 Summary of Risk Assessment Modeling
Approach and Data Sources
The analysis described in this section and in the Technical Background Document and
appendixes is designed as a national analysis to assess the potential risk attributable to inhalation
exposures when certain chemicals and metals are managed as a waste in certain types of waste
management units. Of particular interest are chemicals and metals managed as wastes that are
not regulated under RCRA as hazardous wastes. The purpose of this analysis is to determine
which chemicals and waste management units are of
potential national concern purely from a risk
perspective; it is not intended to draw conclusions
concerning regulatory coverage. This information,
combined with preliminary information presented in the
May 1998 Air Characteristic Study on regulatory
coverage and on the presence of these chemicals in
nonhazardous waste, will be useful in determining the
possible need to expand regulatory coverage in the
future.
This section provides a general overview of the
approach and primary data sources used and discusses
the major components of the analysis-emissions
modeling, dispersion modeling, and exposure
modeling/risk estimation. Technical details on the
models and a complete set of inputs and associated
references are provided in Volume II.
3.1 Overview of Modeling Approach
The overall goal of this risk analysis is to
estimate the concentrations of constituents that can be
present in a waste management unit (WMU) and remain
protective of human health. These protective waste
concentrations were calculated for 104 constituents1
including volatiles, semi-volatiles, and metals. These
The Air Characteristic Study addresses:
# 105 constituents
#
4 WMU types
- landfill
- land application unit (LAU)
- wastepile (WP)
- tank
#
5 receptors
- adult resident, exposure starting
age 19 years
- child resident, exposure starting
age 0-3 years
- child resident, exposure starting
age 4-10 years
- child resident, exposure starting
age 11-18 years
- off-site worker
# direct inhalation only
# volatiles and particulates
# 6 distances from the site
# 3 risk endpoints or averaging times
- chronic (over 1 year)
- subchronic (1 month) - LAU, WP
- acute (1 day) - LAU, WP
1 105 were addressed but one constituent, 3,4 dimethylphenol, did not have an inhalation
benchmark.
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constituents were selected for their potential to result in risk from inhalation exposure. Workers,
adults, and children were evaluated for three different types of exposures or risk endpoints:
chronic (over 1 year), subchronic (1 month), and acute (1 day). Estimating protective
concentrations required a multistep modeling process that could relate the concentrations in
ambient air at a receptor point that could create a health effect to a concentration in the waste
management unit. To achieve this, the analytical approach for this analysis is based on three
primary components:
# Emissions modelingcharacterizing emissions from a WMU
# Dispersion modelingdescribing the transport of these emissions through the
ambient environment
# Exposure modeling/risk estimationestimating exposure to a receptor and then
backcalculating to arrive at a waste concentration (Cw) that presents a risk equal to
a prespecified risk level (e.g., 1 in 1 million, or 1E-6).
To illustrate the scenario that was modeled for this study, Figure 3-1 is a conceptual
diagram of a waste site. Constituents managed in the WMU can be released as gases if they
volatilize and as particulates if the constituent attaches to solid particles in the waste. Once the
constituent is released from the site, the ambient air provides a medium for the transport of the
airborne constituent. The direction the constituent travels and its concentration in the air are
determined by meteorological conditions in the surrounding area such as wind direction, air
temperature, and atmospheric stability at the time it is released. Because meteorological patterns
are dynamic, the concentration of the constituents in the air varies over time and people who live
and work at various locations around the WMU have different inhalation risks. The risk to an
individual from the release of a constituent also depends upon characteristics of that individual
such as body weight, inhalation rate, and the length of time that individual remains in the area
around the WMU. These last characteristics are the reason that this assessment considers the
Figure 3-1. Conceptual diagram of a waste site.
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exposure to multiple types of receptors: adult residents, child residents of various ages, and
workers.
In order to model the scenario described above, the preliminary requirements for the
analysis included:
# Emissions models for the various WMUs to provide estimates of gas and particle
releases from the unit
# A dispersion model capable of modeling area sources for chronic (over 1 year),
subchronic (1 month), and acute (1 day) releases
# An exposure model for locating receptors proximate to the WMUs and estimating
their exposure
# A risk model that combines the exposure characteristics of different types of
receptors with constituent-specific toxicity benchmarks.
# The ability to backcalculate Cw from a prespecified risk level (e.g., 1E-6).
For each constituent and each WMU type, EPA wanted to be able to specify a Cw that
would not exceed a target risk level (e.g., 1 in 100,000, or 1E-5) in more than a specified
percentage (e.g., 10 percent) of the cases being modeled. Therefore, a probabilistic modeling
approach, which would produce a distribution of Cw's, was needed, as opposed to a deterministic
approach, which would only produce a point estimate. A deterministic analysis produces a point
estimate because it uses a single value for each parameter in the analysis. A probabilistic
approach considers the variability in the inputs required to estimate the concentration nationally.
This type of approach produces a distribution of results because the method iterates through the
analysis more than once, allowing the input parameters in the analysis to take on different values
for each iteration from a distribution of values. For this analysis, EPA used a Monte Carlo
simulation. This is a type of probabilistic analysis that can be used when the distribution of some
or all input variables is known or can be estimated. A large number of iterations of the
calculations are performed (i.e., 1,000), with a value for each input variable selected at random
from the variable's distribution and the result (in this case, Cw) calculated for each iteration. The
results of each iteration are combined into a distribution of Cw. It was assumed that the modeled
cases represent the national distribution of risk-specific concentrations.
The probabilistic approach described above was used to model chronic exposures. A
deterministic approach designed to produce a more high-end point estimate was used to model
acute and subchronic exposures. The acute/subchronic approach uses the maximum exposure
point at any given distance, so no variability in receptor location is accounted for. It also uses the
meteorological conditions that produce the maximum air concentration for a 24-hour or 30-day
time period over 5 years of meteorological data. The results from the acute/subchronic analysis
are comparable to the 100th percentile of the distribution generated for the chronic analysis. It
should be noted that acute/subchronic exposures were only assessed for land application units
(LAUs) and wastepiles, which may have episodic loading events. There are a variety of other
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differences in the acute/sub chronic approach in how the emission rates and dispersion factors
were calculated; these are described in more detail in Sections 3.2.2 and 3.2.3.
To estimate volatile emissions from each type of WMU, EPA's CHEMDAT8 model was
used. For the landfill, LAU, and wastepile, the concentration of hazardous constituent in the
surface layer of the soil (hereafter referred to as soil concentration) was estimated using a mass
balance approach (i.e., competing pathways such as volatilization, adsorption, and
biodegradation are accounted for). Particulate emissions due to wind erosion were modeled for
land-based units (landfills, LAUs, and wastepiles). Landfills and LAUs were modeled as
ground-level sources using the Cowherd model (U.S. EPA, 1985b, 1988). Wastepiles were
modeled as elevated sources using the AP-42 model for wind erosion from aggregate storage
piles (U.S. EPA, 1985a). To obtain the emission rate of constituent sorbed to particulate matter,
the emission rate of particulate matter was multiplied by the soil concentration calculated by
CHEMDAT8. This was done to account for the portion of the original constituent concentration
that would remain in the waste after volatilization and biodegradation losses, and so would
realistically be available for emission in the particulate phase.
The modeling assumes waste is continuously added to landfills and tanks, while LAUs
and wastepiles have noncontinuous, episodic waste loadings. To capture potential peaks in
emissions immediately after episodic loading events, acute and subchronic exposures were
evaluated for LAUs and wastepiles.
Dispersion modeling was performed for each WMU using EPA's Industrial Source
Complex Model Short-Term (ISCST3) to develop unitized air concentrations (UACs) for vapors
and particulates. UACs are dispersion coefficients based on a unit emission (i.e., 1 |ig/m2-s) for
use in a backcalculation. UACs varied depending on the averaging time (i.e., chronic,
subchronic, or acute), the size of the WMU, the distance and direction of the receptor from the
WMU, and the associated meteorological station. Dispersion modeling for vapors did not
account for depletion, as sensitivity analysis showed that depletion of vapors has a negligible
impact on air concentration of vapors. Dispersion modeling for particulates accounted for dry
depletion of particles, since a sensitivity analysis showed that dry depletion has a potentially
significant impact on air concentrations of particulates. Wet depletion of particulates was not
accounted for in the dispersion modeling, as sensitivity analysis showed that wet depletion has
little impact on air concentration.
The air concentration at any specific receptor is the product of the emission rate
(in |ig/m2 -s) and appropriate UAC (in [|ig/m3]/[|ig/m2 -s]). Air concentrations were estimated
for chronic, subchronic, and acute exposures (using averaging times of 1 year, 1 month, or 1
day), based on a combination of volatile and particulate emissions.
Many previous risk analyses have used the maximum point of exposure at some
prespecified distance from the WMU as the point for analysis. Such an approach is usually
criticized as being overly conservative because it does not consider the possibility of no one
living at that exact point. Because individuals may potentially be located in any direction and at
various distances from a facility, this analysis developed an explicit way to incorporate this
consideration. First, a sensitivity analysis was conducted to determine a reasonable distance at
which to bound the analysis. This sensitivity analysis showed that, beyond 1,000 m, most air
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concentrations are a small percentage (less than 10 percent) of the concentration at the point of
maximum exposure. Therefore, 1,000 m was used as the outer bound on the distance of receptors
included in this analysis. A receptor grid was set up to allow individuals to reside in any of 16
directions and at distances of 25, 50, 75, 150, 500, and 1,000 m from the edge of the unit.
For this analysis, five receptors were included: an adult resident, a child resident with
exposure starting between 0 and 3 years old, a child resident with exposure starting between 4
and 10 years old, a child resident with exposure starting between 11 and 18 years old, and an off-
site worker. These receptors could be located in any of 16 directions and at distances of 25, 50,
75, 150, 500, and 1,000 m from the edge of the unit. Each distance was evaluated separately and
the location of a receptor was allowed to vary among any of the 16 directions. The 16 directions
were equally weighted, so there is equal probability of a receptor's being located anywhere
around the WMU. For acute and subchronic exposures, receptors were modeled at 25, 50, and
75 m because it was assumed that the greatest possibility of acute exposure would be closest to
the site.
3.2 Conducting the Analysis
As discussed earlier, the analysis consists of three main parts: emissions modeling,
dispersion modeling, and exposure modeling/risk estimation. Figure 3-2 shows the model
framework. Emissions and dispersion modeling was performed first and the results used as
inputs to the exposure modeling/risk estimation. In addition, a database containing
characterizations of WMUs was used. The goal of the analysis is to backcalculate a waste
concentration that will result in a specified risk. Because risk is assumed to be linear with waste
concentration under most circumstances, a waste concentration was generated by forward-
calculating a risk associated with a unit concentration in the waste (i.e., 1 mg/kg for land-based
units and 1 mg/L for tanks), then scaling the unit concentration using the ratio of target risk to
calculated risk. The assumption of linearity is accurate for the dispersion modeling and the
exposure and risk modeling. The emissions model is linear for land-based units and tanks
without biodegradation. The emissions model for tanks with biodegradation is nonlinear at the
concentration where biodegradation shifts from first order to zero order. The results for tanks
with biodegradation were backcalculated using first-order emission rates; however, if this result
exceeded the concentration at which biodegradation becomes zero order, the result was adjusted
to be based on zero-order emission rates. Even when the emissions model is linear, it is possible,
using this approach, to backcalculate waste concentrations that exceed the solubility or soil
saturation concentration for the chemical. Results that exceed the solubility or soil saturation
concentration under neutral conditions are footnoted in the result tables (soil saturation
concentration and solubility can vary according to site-specific temperature and pH conditions).
Emissions modeling was performed for all WMUs and all chemicals, assuming a unit
concentration of the chemical in the waste (1 mg/kg for land-based units or 1 mg/L for tanks).
These emissions were used as inputs to Step 2 of the exposure modeling/risk estimation portion
of the model.
Dispersion modeling was performed for 76 representative WMU areas and height
combinations and 29 meteorological locations, assuming a unit emission rate of 1 //g/m2-s. This
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Emission Modeling
For each chemical and WMU,
estimate:
Volatile emissions
Participate emissions
Remaining average waste/
soil concentration
1
Select constituent and waste
management unit (WMU) type
Z Select WMU site from WMU database
Z Characterize site (area, height, and met station)
Dispersion Modeling
For each of 76 WMU
area/height combinations
and 29 meteorological
stations, estimate UAC
at each of 96 receptor
locations.
Select receptor location for each distance
Interpolate UAC for site
(based on area, height, and met station)
Select exposure factors for each receptor
(chronic exposure to carcinogens only)
Determine risk-specific waste concentration (CJ for
Monte Carlo realization for each receptor
Select next receptor location for simulation
Select 85th, 90th, and 95th percentile of risk-specific waste
concentration (Cw) from all realizations for this site
Next WMU simulation
Construct histogram for national risk-specific waste
concentration (Cw) for this type of WMU using 90th
percentile result from realizations for each site
Next constituent and WMU type
Monte Carlo iterations (1,008)
Figure 3-2. Model framework.
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produced vapor and particle-phase UACs for each area/height combination, meteorological
station, and receptor location, which were used as the basis from which to interpolate in Step 4 of
the exposure modeling/risk estimation portion of the model.
The analytical framework shown in Figure 3-2 consists of a series of steps and loops. In
Step 1, a chemical and WMU type (e.g., landfills) were selected (thus, all landfills were analyzed
as a group for each chemical, and so on).
In Step 2, a WMU was selected from the data file for that unit type. For example, for
landfills, the database has a data record containing the facility identification and WMU
characteristics such as surface area, depth, and waste quantity managed per year for each of 801
landfill units. The database also has a sampling weight for each facility that defines how many
facilities nationally were represented by that facility. An assigned meteorological station was
added to the database based on locational information for each WMU. The model simulation
starts with the first record and moves to each successive record. For each WMU record, the
associated emission rate for that WMU and chemical was obtained from the emission modeling
results.
In Step 3, receptor locations were selected by choosing at random one of the 16 directions
modeled in the dispersion modeling. Receptors were modeled in that direction at each of six
distances from the site.
In Step 4, a UAC was interpolated for the WMU. Due to the long run time of ISCST3 for
area sources, UACs were modeled for only 76 selected WMU area/height combinations for each
meteorological station and receptor location. To calculate a UAC corresponding to the WMU's
actual area and height, EPA first chose the modeled height closest to the actual unit height, then
interpolated between the UACs for the two closest of the areas modeled. For example, the first
three areas modeled for wastepiles were 20, 162, and 486 m2. These were modeled at heights of
1, 2, 4, 6, and 8 m. For a WMU with an actual area of 100 m2 and an actual height of 3.5 m, the
UAC was interpolated from the UACs for 20 m2/4 m high and 162 m2/4 m high. For a WMU
with an actual area of 200 m2 and an actual height of 6.9 m, the UAC was interpolated from the
UACs for 162 m2/6 m high and 486 m2/6 m high.
In Step 5, for chronic exposures to carcinogens, values of exposure factors such as body
weight, inhalation rate, and exposure duration were chosen at random from distributions of these
parameters (developed from data in the Exposure Factors Handbook, U.S. EPA, 1997c and
1997d) to capture the variability in exposure factors for a given receptor. These exposure factors
differ for different receptor types (such as adults, children, and workers). Noncarcinogens were
not assessed in this manner because the health benchmarks, such as EPA's reference
concentration (RfC), are expressed in terms of ambient concentration and cannot be adjusted for
variations in these exposure factors. Similarly, acute and subchronic health benchmarks are
expressed as ambient exposure concentrations and cannot be adjusted for variability in exposure
factors.
In Step 6, the emission rate, UACs, and, if applicable, the exposure factors, were
combined with the health benchmark for the chemical to estimate risk (for chronic exposure to
carcinogens) or hazard quotient (for acute and subchronic exposures, and chronic exposures to
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noncarcinogens) associated with the unit concentration modeled. This risk was then compared to
the target risk of 1 in 1 million, 1 in 100,000, or 1 in 10,000 (i.e., 1E-6, 1E-5, or 1E-4) for
carcinogens, and the ratio was used to scale the unit concentration to a concentration in the waste
(Cw) that would result in the target risk at that receptor. A similar technique was used for scaling
the hazard quotient for noncarcinogens.
Steps 3 through 6, which form the core of the Monte Carlo simulation, were then repeated
1,008 times for each WMU, resulting in a distribution of Cw for that WMU for each receptor
(adult, child, or worker) at each distance from the site (25, 50, 75, 150, 500, and 1,000 m) for a
specific risk criteria (i.e., 1E-4, 1E-5, or 1E-6 for carcinogens and 10, 1, or 0.25 for
noncarcinogens). Once 1,008 iterations had been performed for a WMU, various percentiles
were selected from the distribution to characterize it. These percentiles represent the percentage
of receptors protected at the WMU.
Steps 2 through 6 were then repeated to obtain distributions of Cw for each WMU in the
database. These distributions are somewhat different for carcinogens and noncarcinogens and for
chronic, subchronic, and acute exposures. For chronic exposure to carcinogens, they represent
both the potential variability in location around a WMU, as well as the variability in exposure
duration, inhalation rate, and body weight for each receptor type. For noncarcinogens and for
subchronic and acute exposures, variability in these exposure factors is not considered because
the measure of risk is a ratio of air concentrations. For chronic exposures to noncarcinogens, the
distributions represent the variability in location around the WMU at a specific distance. For
subchronic and acute exposures, only point estimates were made at various distances using the
receptor located at the point of maximum air concentration for that distance.
The cumulative distribution of Cw for each WMU is presented as the percentage of
receptors that are at or below the risk criteria for any Cw (see Figure 3-3, left side). For example,
90 percent of all adult residents at a distance of 150 meters have a predicted risk at or below 1 in
100,000 (1E-5) if the concentration of the chemical (e.g., cumene) in the landfill is 1 mg/kg (see
point a). A second landfill may have a 90 percent protection level for all adult residents at 150 m
at a concentration of 10 mg/kg (point b), and a third landfill at a concentration of 100 mg/kg
(point c). Thus, in Step 7, for each WMU, the distribution shows the percent of potential
receptors at or below a specified risk level for each concentration of constituent in the WMU
(Cw) for each distance and each receptor.
In Step 8, once all WMUs of a certain type had been modeled, the distributions of Cw for
all individual WMUs of the same type (e.g., landfills) were combined to produce a cumulative
distribution that presents the variability in Cw across all units of a certain type. For a given
percentage of protected receptors (e.g., 90 percent) as described above, the Cw was combined
across all WMUs of a specified type (e.g., landfills) to provide a distribution of the percentage of
sites considered protective at that level, as shown in Figure 3-3 (right side). Figure 3-3, for
example, shows the cumulative distribution of Cw at a 90 percent protection level across all
landfills. From this distribution, the 90th percentile Cw value for all 90 percent protection levels
across all landfills could be estimated. As described above, three landfills that give a 90 percent
protection level (i.e., at 1E-5) for a resident at 150 meters from the unit boundary have
corresponding Cw values of 1 mg/kg, 10 mg/kg, and 100 mg/kg (see points labeled a, b, and c).
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WMU 1
1,000
1 10 100 1,000 10,000
Cw (ppm)
Figure 3-3. Combination of results for individual WMUs
into a distribution across all WMUs.
These values plus similar values from all other landfills constitute the cumulative
distribution. The Cw value that is protective of 90 percent of receptors across 90 percent of the
sites is referred to in this study as the 90/90 protection level. These distributions were developed
for each unit type, each receptor type, each risk criteria, and each distance from the WMU.
These cumulative distributions are intended to encompass the variability across WMUs.
Thus, the variability in WMU characteristics and in meteorological settings is included in these
distributions.
study.
This process was repeated from Step 1 for each chemical and WMU type analyzed in this
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Volume I Section 3.0
3.2.1 Data Sources
The Industrial D Survey database (Shroeder et al., 1987) was the primary source of data
on WMUs used in this analysis. This database provides information on each of the WMUs
assessed, with the exception of tanks. Tank data are from EP A's National Survey of Hazaradous
Waste Treatment, Storage, Disposal and Recycling Facilities (TSDR Survey, U.S. EPA, 1987).
The Industrial D Survey database contains information on the size and capacity of a statistical
sample of each WMU type, general location information, and statistical weights for each facility
in the sample. The statistical sample was designed to represent all industrial waste management
units not regulated under the RCRA hazardous waste program at the time the survey was
conducted in 1987. The weights in the database indicate the number of facilities represented by
each facility in the sample. For this assessment, it is assumed that the data contained in this
database provide an appropriate representation of the characteristics of each WMU type and of
the general location of these types of facilities with respect to climate regions of the country.
Meteorological stations provided temperature and windspeed data as inputs to the
emissions model and a large set of inputs for the dispersion model. Although meteorological
data are available at over 200 meteorological stations in the United States (see, for example,
Support Center for Regulatory Air Models (SCRAM) Bulletin Board at http://www.epa.
gov/scramOOl), various resource constraints prevented the use of all available data sets in this
analysis. Therefore, a set of 29 stations was used that had been selected as representative of the
nine general climate regions in the contiguous United States in an assessment for EPA's
Superfund Soil Screening Level (SSL) program (EQM, 1993).
In EPA's Superfund study, it was determined that 29 meteorological stations would be a
sufficient sample to represent the population of 200 meteorological stations and predict mean
dispersion values with a high (95 percent) degree of confidence. The 29 meteorological stations
were distributed among the nine climate regions based on meteorological representativeness and
variability across each region. Large-scale regional average conditions were used to select the
actual stations.
The 29 meteorological stations are listed in Section 5 of Volume II. To assign each
Industrial D or TSDR facility to a meteorological station, EPA used a geographic information
system (GIS) to construct areas around each station that encompass the areas closest to each
station. The boundaries of these areas were then adjusted to ensure that each boundary encloses
an area that is most similar in meteorological conditions to those measured at the meteorological
station. First, the boundaries were adjusted to correspond to Bailey's ecological divisions (Bailey
et al., 1994), which are defined primarily on physiography and climate. The boundaries were
further adjusted for coastal (including Great Lakes) areas and the central valley of California to
ensure that these stations were used only in regions with similar meteorology. Based on zip
codes in the Industrial D Survey database and EPA IDs in the TSDR database, the sites were then
overlaid on this GIS coverage, and meteorological station assignments were then exported for use
in the modeling exercise. Several sites in Alaska, Hawaii, and Puerto Rico were deleted from the
analysis at this point because the 29 meteorological stations are limited to the continental United
States.
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Volume I Section 3.0
Figure 3-4 shows the final meteorological station boundaries used for the study along
with the zip code centroid locations for the Industrial D sites.
3.2.2 Emissions Modeling
Both volatile emissions (for all WMU types) and particulate emissions due to wind
erosion (for land-based WMUs) were included in the risk analysis. To assess these two types of
emissions, three parameters had to be modeled: volatile emission rate, long-term average soil
concentration in the unit (for LAUs, landfills, and wastepiles), and particulate matter emission
rate.
EPA's CHEMDAT8 model was selected as the model to estimate volatile emissions rates
and long-term average soil concentrations in the WMU. The CHEMDAT8 model was originally
developed in projects funded by EPA's Office of Research and Development (ORD) and Office
of Air Quality Planning and Standards (OAQPS) to support National Emission Standards for
Hazardous Air Pollutants (NESHAP) from sources such as tanks, surface impoundments,
landfills, wastepiles, and land application units for a variety of industry categories including
chemical manufacturers, pulp and paper manufacturing, and petroleum refining. It also has been
used to support the emissions standards for hazardous waste treatment, storage, and disposal
facilities (TSDF) (U.S. EPA, 1991) regulated under Subpart CC rules of RCRA, as amended in
1984. The CHEMDAT8 model is publicly available and has undergone extensive review by both
EPA and stakeholder representatives. The CHEMDAT8 spreadsheet model and model
documentation may be downloaded at no charge from EPA's web page
(http://www.epa.gov/ttn/chief/software.html).
The CHEMDAT8 model considers most of the competing removal pathways that might
limit air emissions, including adsorption, hydrolysis (for tanks only), and biodegradation.
Adsorption/absorption is the tendency of a chemical or liquid media to attach or bind to the
surface or fill the pores of particles in the soil or waste and therefore not volatilize into the air.
This tendency to adsorb to or absorb in particles is an important process for estimating the
concentration of the chemical on particles emitted to the air due to wind erosion. CHEMDAT8
in its original form models adsorption for land-based units by presuming that the entered waste
concentration is in liquid phase. Because waste concentrations are more typically measured as
total concentration (liquid plus solid phase), CHEMDAT8 was modified to model adsorption
explicitly for an entered total waste concentration for land-based units. Biodegradation is the
tendency of a chemical to be broken down or decomposed into less complex chemicals by
organisms in the waste or soil. Similarly, hydrolysis is the tendency of a chemical to be broken
down or decomposed into less complex chemicals by reaction with water. Chemicals that
decompose due to biodegradation or hydrolysis have lower potential for emission to the air as
gases or particles than those that do not. Loss of contaminant by leaching or runoff is not
included in the CHEMDAT8 model. Both leaching and runoff are a function of a chemical's
tendency to become soluble in water and follow the flow of water (e.g., due to rainfall) down
through the soil to groundwater (leaching) or downhill to surface water (runoff). These two
mechanisms would also make less chemical available for emission to the air as a gas or as
particles. As such, CHEMDAT8 is considered to provide reasonable to slightly high
(environmentally protective) estimates of air emissions from the land-based units.
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| | US States
Bailey's Ecoregion Divisions
i Hot Continental Division
Hot Continental Regime Mountains
Marine Division
Marine Regim e Mountains Redwood Forest Province
Mediterranean Division
: Mediterranean Regime Mountains
Prairie Division
Savanna Division
: Subtropical Division
| Subtropical Regime Mountains
Temperate Desert Division
Temperate Desert Regime M ountains
; Temperate Steppe Division
Temperate Steppe Regime Mountains
Tropicalfiubtropical Desert Division
Tropical/Subtropical Regim e Mountains
Tropical.^ubtropical Steppe Division
Warm Continental Division
Warm Continental Regime Mountains
#Met. station regions created from thiessen polygons
and Bailey's Ecoregion boundaries.
Created 5/5/98
File: eco_29met_sites.api
o
fI
K
Figure 3-4. Meteorological station regions.
O'
s
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Volume I Section 3.0
Two different models were used to model wind erosion: one for wastepiles (elevated
sources) and one for landfills and land application units (ground-level sources). The Cowherd
model (U.S. EPA, 1985b and 1988) was selected for modeling wind erosion emissions from
ground-level sources, and the AP-42 model for wind erosion from aggregate storage piles (U.S.
EPA, 1985a) was selected for modeling wind erosion emissions from wastepiles. Newer
versions of both of these models are available; however, the newer versions are event-based
algorithms that require extensive site-specific data that were not available for the sites modeled
in this analysis. The versions used probably result in somewhat higher particulate emissions
estimates than the event-based algorithms would. This overestimation of particulate emissions is
not significant for volatile chemicals, as particulate emissions were found to be a negligible
fraction (less than 2 percent in most cases) of total emissions for the volatile chemicals modeled
in land-based units. The protective waste concentrations (Cw's) for metals other than mercury
(which do not volatilize and are therefore based solely on particulate emissions) may be
somewhat lower as a result of this overestimation of emissions.
Both volatile and particulate emissions were estimated for the landfill, land application
unit, and wastepile, while only volatile emissions were estimated for tanks.
3.2.2.1 Estimating Volatile Emissions. The modeling scenario and critical parameters
required for each type of WMU are provided in the following subsections. A more detailed
discussion of the emissions modeling is provided in Volume II.
The input parameters used for the CHEMDAT8 land-based unit emissions model are
presented in Table 3-1.2 Of these parameters, two are actually flags to determine which model
equations to apply: the aqueous waste flag and the biodegradation flag. The most important flag
for emission estimates is probably the aqueous waste flag. This flag tells the CHEMDAT8
model which equilibrium partitioning model to use between the liquid and gas phases. For
organic wastes, the model uses Raoult's law and the liquid-to-air partition coefficient becomes
proportional to the contaminant's partial vapor pressure. For aqueous wastes, the model uses
Henry's law and the liquid-to-air partition coefficient becomes proportional to the contaminant's
Henry's law coefficient.
All land-based WMUs were modeled twice; once assuming unit concentration
(concentration set to 1 mg/kg, assuming Henry's law applies) and once assuming pure component
(concentration set to 1E+6 mg/kg, assuming Raoult's law applies). The results presented in
Section 4 and in Volume III are based on the aqueous phase emission rates (unit concentration
and Henry's law). The pure component emission rates were used only to identify chemicals for
which greater emissions occur from the organic phase than from the aqueous phase (which is
rare) or to identify chemicals for which the aqueous-based results exceeded soil saturation
concentrations or solubility limits at neutral pH and standard temperature and to note for these
whether the target risk or hazard quotient would be exceeded modeling pure component.
2The data entry form in the CHEMDAT8 model refers to oil rather than waste; the term waste is used here
for clarity.
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Table 3-1. CHEMDAT8 Land-Based Unit Model Input Requirements
Input Parameter
Data Source/Assumption
Loading (g waste/cm3 soil)
Concentration in waste (ppmw)
Depth of tilling (or unit) (cm)
Total porosity
Air porosity (0 if unknown)
Molecular weight of waste (g/mol)
Aqueous waste flag:
Time of calculation (days)
Biodegradation Flag:
Temperature (°C)
Windspeed (m/s)
Area (m2)
Fraction organic carbon
Waste quantity and/or density from Ind. D Survey
1 for unit concentration run; 1E+6 for pure component run
Assumed or set by capacity
Assumed default value of 0.5
Assumed default value of 0.25
18 for unit concentration run; 147 for pure component run
For aqueous waste, enter 1
For organic waste, enter 0
Dependent on type of WMU
For biodegradation, enter 1
For no biodegradation, enter 0
Set by location of WMU
Set by location of WMU
Input from Ind. D Survey
Assigned randomly from distribution
Three other parameters are critical for land-based units: the annual waste quantity, the
temperature, and the biodegradation rate. The annual waste quantity, along with assumptions
regarding the frequency of waste addition and the dimensions of the WMU, combine to influence
a number of model input parameters including loading, concentration of contaminant in the
waste, depth of the unit (or tilling), operational life, and surface area of the WMU.
Temperature is important because it affects the air diffusivity, which affects the
volatilization rate and may affect the biodegradation rate (biodegradation rates were independent
of temperature above 5°C and were set to zero below 5°C). Temperature is the only
meteorological data input that potentially impacts the emissions results for the CHEMDAT8
model for the land-based WMU. The CHEMDAT8 model is insensitive to windspeeds for long-
term emission estimates from land-based units.
The process of biodegradation is important because it lowers both the emission rate and
the average soil concentration. Consequently, biodegradation is an important input parameter,
and the biodegradation rate constants used in the model are critical parameters. Biodegradation
was treated differently for the various WMUs. Landfills are not designed for biodegradation, and
waste in wastepiles managed over short periods will not be affected substantially. Therefore,
both the landfill emission runs and the short-term wastepile emission runs did not include
biodegradation losses. First-order biodegradation was included in the LAU emission runs and
long-term wastepile emission runs.
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Table 3-2 presents the required CHEMDAT8 input parameters for tanks. Three types of
parameters are critical: factors affecting turbulence, waste characteristics affecting
biodegradation, and meteorological inputs.
Factors that affect the relative surface area of turbulence and the intensity of that
turbulence are important in determining the fate of chemicals in tanks. The tank model has
several input parameters that impact the degree and intensity of the turbulence created by the
aeration (or mixing). The tank model is most sensitive to the fraction aerated.
Waste characteristics that influence the rate of biodegradation are important in
determining emissions from both aerated and storage tanks. As shown in Table 3-2, these
parameters include active biomass concentration, total solids in, total organics in, and total
biorate. Biodegradation was modeled for aerated tanks reporting biological treatment. Aerated
tanks reporting other types of treatment, nonaerated treatment tanks, and storage tanks were
modeled with no biodegradation.
Unlike the biodegradation rate model that was used for the land-based units, the
biodegradation rate model used in CHEMDAT8 for tanks depends on the amount of active
biomass in the WMU. Therefore, the active biomass concentration is a critical parameter for
Table 3-2. CHEMDAT8 Tank Model Input Requirements
Input Parameter
Date Source/Assumption
Unit Design
Flow rate (m3/s)
Survey
Depth (m)
Imputed based on volume
Average surface area (m2)
Imputed based on volume and depth
Height above ground (m)
Imputed based on depth
Aeration Parameters
Fraction agitated
Estimated distribution
Total power (hp)
Imputed based on volume
Number of impellers
Imputed based on total power
Impeller diameter (cm)
Estimated constant = 61
Impeller speed (rad/s)
Estimated constant = 130
Power efficiency (unitless)
Estimated constant = 0.83
O2 transfer rate (lbO2/h-HP)
Estimated constant = 3
Submerged air flow (m3/s)
Estimated constant = 0
Waste Characteristics
Active biomass cone, (kg/m3)
Estimated distribution, depends on treatment code
Total solids in (kg/m3)
Estimated distribution
Total organics (COD) In (g/m3)
Estimated distribution
Total biorate (mg/g-h)
Estimated constant =19
Meteorological Data
Temp(°C)
Imputed based on meteorological station
Windspeed (m/s)
Imputed based on meteorological station
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Section 3.0
aerated tanks. Because this parameter can vary widely for different types of tanks, biomass
concentrations were set on a tank-by-tank basis for aerated tanks using process code information
(WMU codes) from the TSDR Survey.
Meteorological inputs are also important for the tank emission model. For nonaerated
treatment tanks and storage tanks, the emission estimates are impacted by both temperature and
wind speed. Because the emissions for aerated tanks are predominantly driven by the turbulent
area and associated mass transfer coefficients, the emissions from the aerated tanks are not
strongly impacted by the wind speed. Aerated tank emissions are impacted by temperature.
Annual average temperatures were used as input to the model based on tank locations.
The following sections describe the emissions assumptions used for determining volatile
emissions for each WMU type.
Landfills. For landfills, annual
average emissions were estimated from
the active landfill cell assuming the active
landfill cell could hold 1 year's worth of
waste material. The emissions for the
active cell were made assuming that the
cell is instantaneously filled and that no
waste cover is applied for the first year.
Therefore, a full year's worth of waste
was available for emissions to the air each
year. Once the cell is covered at the end
of a year, no additional emissions of gases
or particles were modeled from that cell.
Because landfills are not constructed for
the purpose of biodegrading wastes, as are
land application units or biologically
active tanks, and because conditions are
not controlled to foster biodegradation in
landfills, biodegradation was not modeled
in landfills.
Assumptions for Modeling Volatile Emissions
from Landfills
# Landfill operates for 20 years filling 20 equal cells
sequentially.
# The active cell is modeled as being instantaneously
filled at time t=0 and remains open for 1 year.
# Emissions are calculated only for one cell for 1 year
(after 1 year, cells are either depleted of the
constituent or capped).
# Waste is homogeneous with an initial concentration
of 1 mg/kg.
# The waste matrix may be aqueous (Henry's law
partitioning applies) or organic (Raoult's law
partitioning applies).
# Annual average temperature is used (determined by
assigned meteorological station).
# Acute and subchronic exposures were not modeled.
The annual average emission rate
and waste concentration for the active
landfill cell were estimated using annual average meteorological data. A sensitivity analysis
showed no difference in emissions estimates using seasonal meteorological data (less than 2
percent error for most chemicals). The annual average emission rates were used for chronic risk
calculations. Acute and subchronic risks were not considered for landfills.
The average concentration of the waste in the landfill cell was estimated from the
emission fraction by assuming first-order contaminant (concentration) disappearance. The
details of this calculation are provided in Volume II, Section 4. The relationship between the
emission rate and the waste concentration was needed to estimate a concentration in the WMU
that corresponded to a specific risk or hazard quotient (HQ) for a receptor.
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Section 3.0
#
#
#
#
#
#
#
#
Land Application Units. For land
application units, the volatile emissions
were estimated assuming waste additions
24 times per year and first-order
biodegradation for temperatures greater
than 5°C. The emissions were estimated
using monthly average meteorological
data. LAU emissions are time-dependent
(depending on how recently waste was
added) but were modeled as
pseudo-steady-state (i.e., steady-state
emissions were modeled for a series of
short intervals; these estimates were then
averaged to produce a long-term emission
rate). The average emission rate and
associated waste/soil mixture
concentrations were estimated for each
bimonthly period (i.e., the time between
applications). These computations were
carried out for 40 years, and the average
emission rate and soil/waste concentration
for year 40 was used to estimate the long-
term annual average emission rates and
soil/waste concentrations for each
contaminant. The 40-year time period is
long enough to result in steady-state emissions for most chemicals and is longer than most of the
exposure durations used in the analysis. The annual average emission rates were used for chronic
risk calculations. For acute and subchronic risk calculations, emissions were calculated based on
the first 24 hours (for acute) or the first 30 days (for subchronic) after waste was added. In the
absence of biodegradation, higher temperatures would produce higher volatile emissions.
However, when biodegradation is modeled, it slows to zero at temperatures below 5°C, thus
increasing volatile emissions at low temperatures. Therefore, for both acute and subchronic
exposures, emissions were modeled at the maximum monthly temperature and the minimum
monthly temperature, and the one that produced higher emissions was used.
Wastepiles. The wastepile was assumed to remain at a constant volume. Annual waste
additions were therefore matched with a corresponding quantity of waste removed. The average
residence time of the waste (based on the size of the wastepile and the annual waste quantity)
was used to estimate the emission rate and waste concentration across the wastepile. Monthly
average emission/waste concentration estimates were made using monthly meteorological data
and first-order biodegradation for temperatures greater than 5 °C. The resulting monthly average
emissions and waste concentrations were then arithmetically averaged to estimate the long-term
annual average emission rates and waste concentrations for each contaminant. The annual
average emission rates were used for chronic risk calculations. For acute and subchronic risk
calculations, emissions were calculated based on the first 24 hours (for acute) or the first 30 days
Assumptions for Modeling Volatile Emissions
from LAUs
Waste application occurs 24 times per year.
Emissions are modeled as pseudo-steady-state.
Emissions in year 40 are used to estimate long-term
emissions.
Waste is homogeneous with an initial concentration
of 1 mg/kg.
The waste matrix may be aqueous (Henry's law
partitioning applies) or organic (Raoult's law
partitioning applies).
Monthly average temperature was used for chronic
exposure (determined by assigned meteorological
station).
Maximum or minimum average monthly temperature
was used for acute and subchronic exposures
(whichever gave higher emissions).
Biodegradation occurs at temperatures greater than
5°C.
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Section 3.0
(for subchronic) after waste was
added. Because wastepiles are not
designed for biodegradation, there
may be a lag time after waste is
added before enough acclimated
biomass accumulates for
biodegradation to begin. This time
is typically several months, longer
than the 1-day or 30-day periods
modeled for acute and subchronic
exposures. Therefore,
biodegradation was not considered
for wastepiles for acute and
subchronic exposures. In the
absence of biodegradation, higher
temperatures produce higher
emissions. Therefore, for both
acute and subchronic exposures,
emissions were modeled at the
maximum monthly temperature.
Tanks. For all tanks, the
emissions were estimated assuming
units were well-mixed and were
operating at steady state. The tanks
were assumed to have a constant
influent and were assumed to
operate at a constant temperature.
Annual average temperatures and
windspeeds were used to estimate
the operating conditions for the
tanks. A biodegradation rate model
using Monod kinetics was used to
estimate biodegradation rates for
aerated treatment tanks expected to
have biodegradation (based on
process codes). Biodegradation
was not modeled for nonaerated
treatment tanks and storage tanks.
Due to the nonlinearity of
the biodegradation rate model used
in the tank emission estimates,
direct backcalculation of an
acceptable waste concentration may
not be appropriate for some
compounds. Unlike the emission
Assumptions for Modeling Volatile Emissions
from Wastepiles
# Wastepile operates with a fixed volume.
# Waste is homogeneous with an initial concentration of
Img/kg.
# The waste matrix may be aqueous (Henry's Law partitioning
applies) or organic (Raoult's law partitioning applies).
# No specific operating life was assumed for wastepiles.
Residence time of waste in the pile was unit specific.
# Monthly average temperature was used for chronic exposure
(determined by assigned meteorological station).
# Maximum monthly temperature was used for acute and
subchronic exposures.
# Biodegradation occurs at temperatures greater than 5 ° C for
chronic exposures.
# No biodegradation was assumed for acute and subchronic
exposures.
Assumptions for Modeling Volatile Emissions from Tanks
# Tanks operate at steady state.
# Tank is well mixed.
# Waste has an influent concentration of 1 mg/L.
# The waste matrix may be aqueous (Henry's Law partitioning
applies) or organic (Raoult's law partitioning applies).
# Annual average temperature was used for chronic exposure
(determined by assigned meteorological stations).
# Operating life is not an explicit input; assumed to be long
enough to reach steady state.
# Biodegradation rate is first order with respect to biomass
concentrations.
# Biodegradation rate follows Monod kinetics with respect to
contaminant concentrations.
# Hydrolysis rate is first order with respect to contaminant
concentrations.
# Acute and subchronic exposures were not modeled.
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Section 3.0
results from the land-based units, the contaminant concentration used in the analysis may impact
the predicted "normalized" emission rate (i.e., the emission rate in g/m2-s per mg/L of
contaminant). Therefore, the tanks with biodegradation were run at a low concentration (i.e.,
0.001 mg/L) and at a high concentration (i.e., the constituent's solubility). The most appropriate
backcalculated emission value was then selected based on the concentration range of the
backcalculated values and the constituent's biodegradation characteristics (see Volume II, Section
7.9, for further details).
3.2.2.2 Development of Particulate Emissions. Particulate emissions due to wind
erosion were modeled for land-based units (landfills, land application units, and wastepiles).
Particulate emissions from truck movement and other activities at the WMUs were not modeled.
These activities are likely to result in short bursts of particulate emissions and should be modeled
using an event-based emissions model. Such models require more site-specific information than
was available for the sites modeled in this analysis.
Landfills and LAUs were modeled differently than wastepiles because they are ground-
level sources and wastepiles are elevated sources. For both types of WMU, the models described
in this section and in Volume II predict the emission rate of parti culate matter released from a
site due to wind erosion. To obtain the emission rate of constituent sorbed to paniculate matter,
the emission rate of parti culate matter must be multiplied by the soil or waste concentration.
Landfills and
Land Application Units.
Wind erosion emissions
from landfills and LAUs
were modeled using the
Cowherd model (U.S.
EPA, 1985b). A newer
version of Cowherd's
model is available in
U.S. EPA (1988).
However, the newer version is an event-based model that requires detailed site-specific
information unavailable for this analysis. Therefore, it was not used. The older Cowherd model
tends to slightly overestimate emissions relative to the event-based version. Although the degree
to which it overestimates is not known, it is expected to be relatively small. Because particulate
emissions are negligible compared to volatile emissions for the volatile chemicals modeled, this
is only of concern for the metals (other than mercury), which are based only on particulate
emissions.
The Cowherd model estimates the emission of respirable particles (i.e., PM10) due to wind
erosion from a ground-level surface with an unlimited reservoir of erodible particles. Surfaces
are defined as having a limited or unlimited reservoir based on threshold friction velocity (U*).
Surfaces with a U* greater than 0.5 m/s are considered limited; those with U* less than 0.5 m/s
are considered unlimited (U.S. EPA, 1988). Threshold friction velocity is a measure of the
windspeed at the ground surface that would be required to remove particles from the surface.
Examples of limited reservoirs include nonhomogeneous surfaces with stones, clumps of
Inputs and Intermediate Values Used for Wind
Erosion from Landfills and LAUs
Symbol
V
z0
U*
Parameter
Vegetative cover
Roughness height
Threshold friction
Units
fraction
velocity
cm
m/s
Value
0
1
0.5
Source
Assumption
U.S.EPA(1985b)
Assumed unlimited reservoir
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Section 3.0
vegetation, or other nonerodible elements or crusted surfaces. Further, wind erosion is
considered unlikely to occur from surfaces with full vegetative cover.
A detailed explanation of inputs used in the calculation of paniculate emissions is
presented in Section 4 of Volume II including vegetative cover, roughness height, average annual
windspeed, and threshold friction velocity.
Wastepiles. Wind erosion emissions from wastepiles were modeled using an equation
from AP-42 (U.S. EPA, 1985a) for estimating emissions from wind erosion from active storage
piles. The equation gives emissions of total suspended particulates (TSP). Typically, an
equation-specific particle size multiplier is applied to reduce the emissions to a desired size
category, in this case, PM10. No particle size multipliers are given for this equation in AP-42;
however, Cowherd (U.S. EPA, 1988) gives a particle size multiplier of 0.5 for use with this
equation, and this was used.
Important input parameters for this calculation include silt content of waste (i.e., percent
with small particle size), number of days with greater than 0.01 inches of rainfall, and percent of
time that windspeed exceeds 5.4 m/s. Data on the silt content of the wastes being modeled were
not available. A median silt content of 12 percent was used based on "miscellaneous fill
material" from AP-42 (U.S. EPA, 1985a). The number of precipitation days and the frequency of
windspeed greater than 5.4 m/s were location-specific; values were obtained from NOAA (1992)
and are summarized in Section 4 of Volume II.
#
Assumptions Made for Dispersion Modeling
Dry depletion was activated in the dispersion
modeling for particulates. Depletion was not
considered for vapors.
# An area source was modeled for all WMUs.
3.2.3 Dispersion Modeling
Dispersion modeling was used to
estimate air concentrations to which the
various human receptors were exposed. A
dispersion model (ISCST3) was run to
calculate air concentrations associated with
a standardized unit emission rate (1 |ig/m2-
s) to obtain a unitized air concentration
(UAC), also called a dispersion factor,
which is measured in |ig/m3per |ig/m2-s.
Total air concentration estimates are then
developed by multiplying the constituent-
specific emission rates derived from
CHEMDAT8 by this dispersion factor.
Running ISCST3 to develop a
dispersion factor for each of the
approximately 3,400 individual WMUs
modeled in this study would have been
very time consuming due to the run time of
the area source algorithm in ISCST3. In
addition, modeling for many different locations requires extensive preprocessing to generate the
detailed meteorological data needed for each location modeled. Therefore, a database of
#
#
#
#
To minimize error due to site orientation, a square
area source with sides parallel to X- and Y-axes was
modeled.
Modeling was conducted using a unit emission rate
of 1 ^g/s-m2.
Receptor points were placed on 25, 50, 75, 150, 500,
and 1,000 m receptor squares starting from the edge
of the source with 16 receptor points on each square.
The rural option was used in the dispersion modeling
since the types of WMUs being assessed are
typically in nonurban areas.
# Flat terrain was assumed.
3-20
-------
Volume I Section 3.0
dispersion factors was developed by running ISCST3 for many separate scenarios designed to
cover a broad range of unit characteristics, including:
# both ground-level and elevated sources
# 14 surface area sizes for landfills and land application units, 29 surface
area-height combinations for waste piles, and 33 surface area-height
combinations for tanks
# 6 receptor distances from the unit (25, 50, 75, 150, 500, and 1,000 meters) placed
in 16 directions in relation to the edge of the unit.
Based on the size and location of a specific unit, an appropriate dispersion factor was
interpolated from the database of dispersion factors using the closest location and the two closest
unit sizes.
In addition, WMUs were assigned to and dispersion modeling was performed for 29
meteorological stations. These were chosen from the more than 200 available to represent the
nine general climate regions of the continental U.S.
Each UAC in the database is specific to one meteorological station, one area-height
combination, one distance from the unit, and one direction from the unit.
3.2.3.1 Model Selection
A number of dispersion models are available through the EPA Support Center for
Regulatory Air Models (SCRAM) Bulletin Board (http://www.epa.gov/scram001/). These
dispersion models were developed for a variety of applications, and each has its own strengths
and weaknesses. This analysis required a model with the capability to model (1) area sources;
(2) ground-level and elevated sources; (3) off-site impacts; (4) vapors and particulates; and
(5) annual, monthly, and daily averaging times.
ISCST3 (U.S. EPA, 1995) was selected for all aspects of this analysis because it met all
the criteria. This model, however, requires considerable run time, which limited the number of
meteorological stations included in this analysis.
3.2.3.2 Meteorological Stations. As stated in Section 3.2.1, due to the considerable run
time of ISCST3 for area sources, a set of 29 meteorological stations selected in an assessment for
EPA's Superfund Soil Screening Level (SSL) program (EQM, 1993) as being representative of
the nine general climate regions of the continental United States was used.
The dispersion modeling was conducted using 5 years of representative meteorological
data from each of the 29 meteorological stations. Five-year wind roses representing the
frequency of wind directions and windspeeds for the 29 meteorological stations were analyzed.
These show that the 29 meteorological stations represent a variety of wind patterns. The wind
roses are presented in Appendix C of Volume II.
3-21
-------
Volume I
Section 3.0
Shape of Wind Rose for
29 Meteorological Stations
Wind direction and windspeed are
typically the most important factors for
dispersion modeling analysis. Wind
direction determines the direction of the
greatest impacts. Windspeed is inversely
proportional to ground-level air
concentrations, so that the lower the
windspeed, the higher the air concentration.
Mixing height and stability class are other
meteorological conditions that influence
dispersion. Mixing height determines the
heights to which pollutants can be diffused
vertically. Stability class is also an important factor in determining the rate of lateral and vertical
diffusion. The more unstable the air, the greater the diffusion.
Shape of Wind Rose
Narrowly distributed
Moderately distributed
Evenly distributed
Bimodally distributed
No. of Stations
10
4
6
9
3.2.3.3 Source
Release Parameters. In the
modeling analysis, four types
of WMUs were considered
(landfill, land application unit,
wastepile, and tank). Because
ISCST3 is sensitive to the size
of the area source, the
relationship between air
concentrations and size of the
area source was analyzed. The
results show that, for relatively
small area sources, air
concentrations increase
significantly as the size of the
area source increases (see
boxes). For large area
sources, this increase in air
concentrations is not as
significant. To address this
model sensitivity yet avoid
modeling approximately
3,400 separate WMUs, EPA
developed area strata that
represented the distribution of
the surface area for each of
the WMU types. The surface
areas were then used in the
dispersion modeling to
provide UACs for each of the
surface areas for use in the
analysis. For elevated
Air Concentrations vs. Surface Area
(Landfills)
400,000 800,000 1,200,000 1,600,000
Surface Area (m )
Note: Largest areas modeled for each WMU type have been omitted from the chart to improve
clarity.
Air Concentrations vs. Surface Area
(2m High Waste Piles)
2 e
o
O
20,000 40,000 60,000 80,000 100,000
Surface Area (m )
Note: Largest areas modeled for each WMU type have been omitted from the chart to improve
clarity.
3-22
-------
Volume I Section 3.0
sources, area-height combinations were modeled that best covered the range of area-height
combinations found in the database. For any specific WMU, a UAC was estimated using an
interpolation routine that used the UACs immediately above and below the actual area of the
unit. For elevated sources, the UACs associated with the modeled height closest to the actual
WMU height were used. The interpolation routine provides a technique for minimizing the
number of ISCST3 runs required while also minimizing the error associated with the difference
between the UACs for preselected areas and the UAC for the actual area of the WMU.
Landfills and LAUs were modeled as ground-level area sources while wastepiles and
tanks were treated as elevated area sources. Fourteen surface areas were selected for modeling
for landfills and LAUs. Twenty-nine surface area-height combinations were selected for
wastepiles and 33 area-height combinations for tanks. The areas were selected using a modified
version of a statistical method called the Dalenius Hodges procedure (see Appendix A, Volume
II for details). This procedure divided into strata the skewed distribution of areas found in the
Industrial D survey database so that all WMUs in the database would be adequately represented.
The median area in each stratum was then used in the dispersion modeling. This procedure is
described in more detail in Section 3 of Volume II.
The selected area-height combinations for the four types of WMUs were modeled with 29
representative meteorological locations in the continental United States to estimate UACs. The
5-year average UACs at all receptor points were calculated for the long-term or chronic exposure
scenario. They were used as inputs to the Monte Carlo analysis and as input to the interpolation
routine discussed above.
A similar methodology and assumptions were used to model dispersion for acute and
subchronic exposures. Since the ISCST3 model uses hourly meteorological data, the outputs
from the model can be used to develop any averaging times equal to or greater than 1 hour. One
set of ISCST3 runs (for all area-height combinations and 29 meteorological stations) was
performed for both acute and subchronic analyses, resulting in 5 years of hourly average
concentrations at each receptor. For each area, meteorological location, and receptor location,
the maximum air concentration for any 24-hour period over the 5 years was selected for acute
exposures. Then, for each area and meteorological station, the maximum 24-hour air
concentration among all receptor locations at each distance modeled was selected, and this was
used as the UAC for that area and meteorological station for acute exposure. The same method
was used to determine the subchronic UAC, except that the maximum 30-day period over the
5 years was used instead of the maximum 24-hour period. It was assumed that the greatest
potential for acute exposure would be closest to the site, therefore, the receptors points were
placed at 25, 50, and 75 meters from the edge of the WMU, in 16 directions at each distance.
3.2.4 Exposure Modeling/Risk Estimation
The previous sections described how emissions and UACs were developed. This section
describes the models used to combine those results with exposure factor distributions to calculate
risk or hazard quotient and risk-specific waste concentration (Cw).
For carcinogens, a Monte Carlo analysis was performed in which the location of the
receptor and various exposure factors (body weight, inhalation rate, and exposure duration) were
3^23
-------
Volume I Section 3.0
varied. For each constituent and WMU type combination, a separate Monte Carlo simulation
was run for each WMU in the Industrial D Survey or TSDR Survey database. The emission rate
for the specific constituent from the specific WMU was used as an input to the Monte Carlo
simulation and was not varied across iterations within a simulation. Approximately 1,000
iterations were performed for each WMU, resulting in a distribution of waste concentrations (Cw)
that would result in the specified risk criteria. This distribution captures the range in waste
concentration attributable to the variability in potential location and in exposure factors
associated with each receptor. From this distribution, the 85th, 90th, and 95th percentiles were
selected to characterize the distribution. These percentiles represent the percentage of receptors
that are protected at the risk criterion for a specific WMU.
When the Monte Carlo simulation had been run for all the WMUs, a cumulative
distribution across all facilities for each protection level (85th, 90th, or 95th percent of
receptors) was obtained for each receptor at each distance. This distribution reflects the
variability across facilities. In developing this distribution, the results were weighted using the
facility weights from the Industrial D Survey data. These weights indicate the number of
facilities in the United States represented by a particular facility in the Industrial D Survey
database. The resulting cumulative distribution accounts for variability across all facilities
represented, not just those actually modeled. The TSDR survey data used to characterize tanks
did not include facility weights; therefore, the tank distributions are not weighted.
Hazard quotients for noncarcinogens depend only on air concentration and the health
benchmark (a reference concentration). Therefore, exposure factors are not used and of the
variables varied in the Monte Carlo analysis, only the location of the receptor is relevant.
Because the location of the receptor is such a simple distribution, a Monte Carlo analysis was
unnecessary for noncarcinogens; the distribution of hazard quotient (and therefore Cw) based on
the distribution of the location of the receptor can be obtained analytically by calculating hazard
quotient (and Cw) for each of the 16 receptor locations (or directions around the site) and taking
the desired percentiles from those 16 values.
Exposure and risk modeling for subchronic and acute exposures differed somewhat from
the modeling for chronic exposures in several respects. All acute and subchronic health
benchmarks are analagous to chronic noncarcinogen benchmarks, so exposure factors were not
used. In addition, receptor location around the site was not varied for acute and subchronic
exposures. Therefore, a Monte Carlo analysis was not performed for subchronic and acute
exposures. Instead, a point estimate of Cw was calculated for each WMU in the Industrial D
database using the single sector that resulted in the maximum air concentration. This point
estimate represents the maximum, or 100th percentile, concentration and therefore is most
comparable to the 100th percentile of the distribution generated by the Monte Carlo model for
chronic exposures. The point estimate can be interpreted as the level at which 100 percent of
receptors are protected at a particular WMU. A distribution across all WMUs of a specific type
was generated from these point estimates, and the 90th percentile of that distribution is presented
in the results for subchronic and acute exposures.
3.2.4.1 Obtain Health Benchmarks. For chronic exposures, standard health
benchmarks (cancer slope factors for carcinogens and reference concentrations for
noncarcinogens) were obtained for each constituent (these are shown in Table 3-3). Chronic
3^24
-------
Volume I
Section 3.0
benchmarks for 15 chemicals were developed explicitly for the Air Characteristic Study.
However, a benchmark could not be developed for one chemical (3,4-dimethylphenol) due to
lack of appropriate data, so, although EPA has addressed this chemical, risks for it could not be
quantified.
Information on acute and intermediate/subchronic inhalation benchmark values and
occupational exposure limits was collected for use in the analysis. These data are also shown in
Table 3-3.
3.2.4.2 Calculate Risk or Hazard Quotient. The risk or hazard quotient associated
with a unit waste concentration was calculated for each iteration based on the calculated air
concentration and the exposure factors selected for the iteration.
Carcinogens. Adult receptors
modeled include adult residents and
off-site workers. Risk for adults is
calculated using long-term average air
concentration that is constant over the
entire exposure duration. The
inhalation rate, exposure frequency,
and exposure duration differ for
residents and workers. Body weight is
the same for all adults, whether
resident or worker. All exposure
factors for adults are held constant over
the entire exposure duration.
Calculation of Risk for Carcinogens for Adults
Risk,
where
Risk,.
CSF
IR
ED
EF
BW
AT
'calc 'd
Cmr * CSF * IR * ED * EF
BW * AT * 365 dlyr
individual risk associated with unit waste
concentration (per mg/kg)
air concentration associated with a unit
waste concentration ([mg/m3]/[mg/kg])
cancer slope factor (per mg/kg-d)
inhalation rate (m3/d)
exposure duration (yr)
exposure frequency (d/yr)
body weight (kg)
averaging time (yr) = 70
Three child age groups, or
cohorts, were used to model child
exposures: 0 to 3, 4 to 10, and 11 to
18 years of age. These cohorts reflect
the age cohorts for which inhalation rate data are available. Results were calculated and saved
for receptors falling into each of these three age cohorts at the start of exposure and presented as
child 1 (0-3), child 2 (4-10), and child 3 (11-18). An exposure duration was selected randomly
for each of the three starting age cohorts from a distribution specific to each starting age cohort.
For each age cohort, exposure begins at a starting age selected at random within the cohort and
then continues through succeeding age cohorts and into adulthood as necessary until the exposure
duration selected for that starting age cohort is reached.
Annual risk for each year of exposure (from starting age to starting age plus exposure
duration) was calculated and summed over the exposure duration for each child receptor. If the
child reached age 19 before the exposure duration ended, adult exposure factors were used for the
remainder of the exposure duration. This approach requires both body weight and inhalation rate
distributions by year of age; however, only body weight is available by year. Inhalation rate is
available only for the age groups used to define the cohorts (0-3, 4-10, and 11-18 years).
Because inhalation rate data could not be disaggregated to individual years of age, we retained
3-25
-------
Table 3-3. Inhalation Health Benchmarks Used in the Air Characteristic Analysis
o
fI
K
CAS#
75-07-0
67-64-1
75-05-8
107-02-8
79-06-1
79-10-7
107-13-1
107-05-1
62-53-3
7440-38-2
7440-39-3
71-43-2
92-87-5
50-32-8
7440-41-7
75-27-4
75-25-2
106-99-0
7440-43-9
75-15-0
56-23-5
126-99-8
108-90-7
Name
Acetaldehyde
Acetone
Acetonitrile
Acrolein
Acrylamide
Acrylic acid
Acrylonitrile
Allyl chloride
Aniline
Arsenic
Barium
Benzene
Benzidine
Benzo(a)pyrene
Beryllium
Bromodichloromethane
Bromoform (Tribromomethane)
Butadiene, 1 ,3-
Cadmium
Carbon disulfide
Carbon tetrachloride
Chloro-1 ,3-butadiene, 2-
(Chloroprene)
Chlorobenzene
Chronic RfC
(mg/m3)
9.0E-03
3.1E+01
6.0E-02
2.0E-05
NA
1 .OE-03
2.0E-03
1 .OE-03
1 .OE-03
NA
5.0E-04
NA
NA
NA
2.0E-05
NA
NA
NA
NA
7.0E-01
NA
7.0E-03
2.0E-02
Ref
I
A
I
I
I
I
I
I
H
I
I
H
H
Inhal URF
(Mg/m3)-1
2.2E-06
NA
NA
NA
1 .3E-03
NA
6.8E-05
NA
NA
4.3E-03
NA
8.3E-06
6.7E-02
8.8E-04
2.4E-03
1 .8E-05
1.1E-06
2.8E-04
1 .8E-03
NA
1 .5E-05
NA
NA
Inhal CSF
(mg/kg/day)'1
7.7E-03
NA
NA
NA
4.6E+00
NA
2.4E-01
NA
NA
1.5E+01
NA
2.9E-02
2.3E+02
3.1E+00
8.4E+00
6.2E-02
3.9E-03
1.8E+00
6.3E+00
NA
5.3E-02
NA
NA
Subchronic
Ref RfC (mg/m3)
I
I
I
I
I
I
N
I
D
I
I
I
I
9.0E-02
3.1E+01
6.0E-02
2.0E-04
3.0E-03
2.0E-02
1.0E-02
1.0E-02
5.0E-03
1.3E-02
7.0E-01
3.1E-01
7.0E-02
2.0E-01
Acute RfC
Ref (mg/m3)
C
A
I
C
H
C
H
H
H
A
H
A
H
SF
6.2E+01
1.1E-04
6.0E+00
2.2E-01
4.0E-04
1.6E-01
2.0E+01
1.3E+00
Refa
A
A
CA
A
CA
A
CA
A
to
(continued)
-------
to
Table 3-3. (continued)
CAS#
124-48-1
67-66-3
95-57-8
7440-47-3
7440-48-4
1319-77-3
98-82-8
108-93-0
96-12-8
95-50-1
106-46-7
75-71-8
107-06-2
75-35-4
78-87-5
10061-01-5
10061-02-6
57-97-6
68-12-2
95-65-8
121-14-2
123-91-1
122-66-7
106-89-8
106-88-7
Name
Chlorodibromomethane
Chloroform
Chlorophenol, 2-
Chromium VI
Cobalt
Cresols (total)
Cumene
Cyclohexanol
Dibromo-3-chloropropane, 1 ,2-
Dichlorobenzene, 1 ,2-
Dichlorobenzene, 1 ,4-
Dichlorodifluoromethane
Dichloroethane, 1 ,2-
Dichloroethylene, 1,1-
Dichloropropane, 1 ,2-
Dichloropropene, cis-1 ,3-
Dichloropropene, trans-1 ,3-
Dimethylbenz(a)anthracene, 7,12-
Dimethylformamide, N,N-
Dimethylphenol, 3,4-
Dinitrotoluene, 2,4-
Dioxane, 1 ,4-
Diphenylhydrazine, 1 ,2-
Epichlorohydrin
Epoxybutane, 1 ,2-
Chronic RfC
(mg/m3)
NA
NA
1 .4E-03
1 .OE-04
1 .OE-05
4.0E-04
4.0E-01
2.0E-05
2.0E-04
2.0E-01
8.0E-01
2.0E-01
NA
NA
4.0E-03
2.0E-02
2.0E-02
NA
3.0E-02
NA
NA
8.0E-01
NA
1 .OE-03
2.0E-02
Ref
D
I
D
D
I
FR
I
H
I
H
I
I
I
I
D
I
I
Inhal URF
(Mg/m3)-1
2.4E-05
2.3E-05
NA
1 .2E-02
NA
NA
NA
NA
6.9E-07
NA
NA
NA
2.6E-05
5.0E-05
NA
3.7E-05
3.7E-05
2.4E-02
NA
NA
1 .9E-04
NA
2.2E-04
1 .2E-06
NA
Inhal CSF
(mg/kg/day)-1
8.4E-02
8.1E-02
NA
4.2E+01
NA
NA
NA
NA
2.4E-03
NA
NA
NA
9.1E-02
1.8E-01
NA
1.3E-01
1.3E-01
8.4E+01
NA
NA
6.8E-01
NA
7.7E-01
4.2E-03
NA
Subchronic
Ref RfC (mg/m3)
D
I
I
H
I
I
H
H
D
D
I
I
2.4E-01
5.0E-04
3.0E-05
1.2E-03
4.0E+00
2.0E-04
2.0E-03
2.0E+00
2.5E+00
2.0E+00
8.1E-01
7.9E-02
1.3E-02
2.0E-02
2.0E-02
3.0E-02
8.0E+00
1.0E-02
2.0E-01
Acute RfC
Ref (mg/m3)
A
A
A
C
C
C
C
H
H
H
C
A
H
H
H
H
C
H
C
4.9E-01
4.8E+00
8.1E-01
2.3E-01
6.0E+00
3.0E+00
Refa
A
A
A
A
CA
CA
(continued)
o'
s
-------
Table 3-3. (continued)
o
fI
K
CAS#
111-15-9
110-80-5
100-41-4
106-93-4
107-21-1
75-21-8
50-00-0
98-01-1
87-68-3
118-74-1
77-47-4
67-72-1
110-54-3
78-59-1
7439-96-5
7439-97-6
67-56-1
110-49-6
109-86-4
74-83-9
74-87-3
78-93-3
108-10-1
80-62-6
1634-04-4
Name
Ethoxyethanol acetate, 2-
Ethoxyethanol, 2-
Ethylbenzene
Ethylene dibromide
Ethylene glycol
Ethylene oxide
Formaldehyde
Furfural
Hexachloro-1 ,3-butadiene
Hexachlorobenzene
Hexachlorocyclopentadiene
Hexachloroethane
Hexane, -
Isophorone
Manganese
Mercury
Methanol
Methoxyethanol acetate, 2-
Methoxyethanol, 2-
Methyl bromide (Bromomethane)
Methyl chloride (Chloromethane)
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
Methyl tert-butyl ether
Chronic RfC
(mg/m3)
3.0E-01
2.0E-01
1.0E+00
2.0E-04
6.0E-01
NA
NA
5.0E-02
NA
NA
7.0E-05
NA
2.0E-01
1 .2E-02
5.0E-05
3.0E-04
1.3E+01
3.0E-02
2.0E-02
5.0E-03
NA
1.0E+00
8.0E-02
7.0E-01
3.0E+00
Ref
D
I
I
H
D
H
H
I
FR
I
I
D
D
I
I
I
H
I
I
Inhal URF
(Mg/m3)-1
NA
NA
NA
2.2E-04
NA
1 .OE-04
1 .3E-05
NA
2.2E-05
4.6E-04
NA
4.0E-06
NA
NA
NA
NA
NA
NA
NA
NA
1 .8E-06
NA
NA
NA
NA
Inhal CSF
(mg/kg/day)'1
NA
NA
NA
7.7E-01
NA
3.5E-01
4.6E-02
NA
7.7E-02
1 .6E+00
NA
1 .4E-02
NA
NA
NA
NA
NA
NA
NA
NA
6.3E-03
NA
NA
NA
NA
Subchronic
Ref RfC (mg/m3)
I
H
I
I
I
I
H
2.0E+00
8.7E-01
2.0E-03
6.0E+00
1.6E-01
1 .2E-02
5.0E-01
7.0E-04
5.8E+01
2.0E-01
1.2E-01
5.0E-04
3.0E-04
2.0E-01
1.9E-01
4.1E-01
1.0E+00
8.0E-01
7.0E+00
2.1E+00
Acute RfC
Ref (mg/m3)
H
A
H
C
A
A
H
H
A
H
C
C
H
H
A
A
H
H
C
A
3.0E-01
9.0E-01
1.3E+00
6.1E-02
5.8E+01
2.0E-03
3.0E+01
2.0E-02
1.9E-01
1.0E+00
3.0E+01
6.1E+00
Refa
CA
CA
A
A
A
CA
CA
CA
A
A
CA
A
to
oo
(continued)
-------
to
Table 3-3. (continued)
CAS#
56-49-5
75-09-2
91-20-3
7440-02-0
98-95-3
79-46-9
55-18-5
924-16-3
930-55-2
108-95-2
85-44-9
75-56-9
110-86-1
100-42-5
1746-01-6
630-20-6
79-34-5
127-18-4
108-88-3
95-53-4
76-13-1
120-82-1
71-55-6
79-00-5
79-01-6
Name
Methylcholanthrene, 3-
Methylene chloride
Naphthalene
Nickel
Nitrobenzene
Nitropropane, 2-
Nitrosodiethylamine
Nitrosodi-n-butylamine
A/-Nitrosopyrrolidine
Phenol
Phthalic anhydride
Propylene oxide
Pyridine
Styrene
TCDD, 2,3,7,8-
Tetrachloroethane, 1 ,1 ,1 ,2-
Tetrachloroethane, 1,1,2,2-
Tetrachloroethylene
Toluene
Toluidine, o-
Trichloro-1 ,2,2-trifluoroethane, 1 ,1 ,2-
Trichlorobenzene, 1 ,2,4-
Trichloroethane, 1,1,1-
Trichloroethane, 1,1,2-
Trichloroethylene
Chronic RfC
(mg/m3)
NA
3.0E+00
3.0E-03
NA
2.0E-03
2.0E-02
NA
NA
NA
6.0E-03
1.2E-01
3.0E-02
7.0E-03
1.0E+00
NA
NA
NA
3.0E-01
4.0E-01
NA
3.0E+01
2.0E-01
1.0E+00
NA
NA
Ref
H
I
H
I
FR
H
I
O
I
A
I
H
H
SF
Inhal URF
(Mg/m3)-1
2.1E-03
4.7E-07
NA
2.4E-04
NA
2.7E-03
4.3E-02
1 .6E-03
6.1E-04
NA
NA
3.7E-06
NA
NA
3.3E+01
7.4E-06
5.8E-05
5.8E-07
NA
6.9E-05
NA
NA
NA
1 .6E-05
1 .7E-06
Inhal CSF
(mg/kg/day)'1
7.4E+00
1.6E-03
NA
8.4E-01
NA
9.4E+00
1 .5E+02
5.6E+00
2.1E+00
NA
NA
1.3E-02
NA
NA
1 .6E+05
2.6E-02
2.0E-01
2.0E-03
NA
2.4E-01
NA
NA
NA
5.6E-02
6.0E-03
Subchronic
Ref RfC (mg/m3)
D
I
I
H
I
I
I
I
H
I
I
SF
D
I
SF
3.0E+00
3.0E-02
2.0E-03
2.0E-02
2.0E-02
6.0E-02
1.2E-01
3.0E-02
3.0E+00
2.7E+00
3.0E+00
4.0E+00
3.0E+01
2.0E+00
3.8E+00
5.4E-01
Acute RfC
Ref (mg/m3)
H
C
C
H
H
C
H
H
H
A
C
C
H
H
A
A
1.0E+01
1 .OE-02
6.0E+00
6.0E+00
2.0E+01
1.4E+00
1.5E+01
1.1E+01
1.1E+01
Refa
A
CA
CA
CA
CA
A
A
A
A
(continued)
o'
s
-------
Table 3-3. (continued)
o
fI
K
CAS#
75-69-4
121-44-8
7440-62-2
108-05-4
75-01-4
1330-20-7
Name
Trichlorofluoromethane
Triethylamine
Vanadium
Vinyl acetate
Vinyl chloride
Xylenes (total)
Chronic RfC
(mg/m3)
7.0E-01
7.0E-03
7.0E-05
2.0E-1
NA
4.0E-01
Ref
H
I
D
I
A
Inhal URF
(Mg/m3)-1
NA
NA
NA
NA
8.4E-05
NA
Inhal CSF
(mg/kg/day)-1
NA
NA
NA
NA
3.0E-01
NA
Subchronic
Ref RfC (mg/m3)
H
7.0E+00
7.0E-02
7.0E-05
2.0E-01
7.7E-02
3.0E+00
Acute RfC
Ref (mg/m3)
H
C
C
H
A
A
7.0E-04
1.3E+00
4.3E+00
Refa
C
A
A
CAS = Chemical Abstract Service.
CSF = Cancer slope factor.
NA = Not available.
RfC = Reference concentration.
URF = Unit risk factor.
"References:
I = IRIS (U.S. EPA, 1999)
H = HEAST (U.S. EPA, 1997a)
A = Agency for Toxic Substances Disease Registry; minimal risk levels (MRLs) (ATSDR, 1999)
SF = Superfund Risk Issue Paper (U.S. EPA, 1996, U.S. EPA, nd)
FR = 63 FR 64371-402 (U.S. EPA, 1998)
N = NCEA Risk Assessment Issue Paper (U.S. EPA, 1994b)
D = Developed for this study
O = Other source (see Volume II, Sections 6.1.1 and 6.1.2)
C = Calculated from chronic RfC value
CA = Cal EPA 1-h acute inhalation reference exposure levels (RELs) (CalEPA, 1998)
E = Acute exposure guideline level (AEGL) (U.S. EPA, 1997b)
-------
Volume 1
Section 3.0
year-by-year body weights and used the inhalation rate for the cohort associated with each year of
age for that year. Thus, the inhalation rate is a constant for all ages within an age cohort and
changes only when the receptor ages from one cohort to the next. Both EPA and a statistician
experienced in working with EFH exposure factor data (L. Myers, RTI, personal communication
with Anne Lutes, RTI, March 16, 1998) preferred this approach over the alternative of pooling
body weights to the age cohort age ranges because it retains the most detail from the available
data without sacrificing statistical rigor.
Noncarcinogens. Because
the hazard quotient equation for
noncarcinogens does not consider
exposure factors, there is no
difference in results for different
receptors at the same location (e.g.,
adult resident, child resident, and
off site worker). Therefore, only an
adult resident was modeled for
noncarcinogens.
Calculation of Hazard Quotient for Noncarcinogens
where
RfC =
cmc a RfC
hazard quotient associated with unit
waste concentration (per mg/kg)
air concentration associated with a unit
waste concentration ([mg/m3]/[mg/kg])
reference concentration (mg/m3)
When a particular constituent had both carcinogenic and noncarcinogenic effects, the
carcinogenic risk was used, because it is generally more protective.
3.2.4.3 Risk-Specific Waste Concentration. The final step in each iteration was to
backcalculate the risk-specific waste concentration from the risk or hazard quotient
corresponding to a unit waste concentration. Because risk is linear with respect to waste
concentration in the models used in this analysis, this may be done by a simple ratio technique.
As mentioned, risk is assumed to be linear with waste concentration. The assumption of
linearity is accurate for the dispersion modeling and the exposure and risk modeling. However,
the emissions model is linear only for land-based units and for tanks with no biodegradation; for
tanks with biodegradation, the emissions model is nonlinear with respect to biodegradation. At
low concentrations, biodegradation in tanks is first order. However, at concentrations in excess
of the half-saturation level, biodegradation becomes zero order. In order to address this,
emissions were modeled in the aqueous phase at 0.001 mg/L to capture first-order biodegradation
and at the solubility to capture zero-order biodegradation. These emission rates then were
normalized to a unit concentration by dividing by 0.001 or the solubility. When the
backcalculated waste concentration based on first-order biodegradation exceeded the half-
saturation constant, suggesting that biodegradation would be zero order, it was recalculated based
on the normalized solubility limit emission rate.
The results for all WMU types presented in Section 4 and Volume III were calculated as
described above using aqueous-phase emission rates. Most of the waste streams managed in the
types of units modeled are expected to contain constituents in the aqueous, rather than the
organic, phase; therefore, this is the most realistic scenario. However, results based on organic-
phase emissions are of interest in two circumstances: when organic-phase emissions are higher
than aqueous-phase emissions, and when backcalculated results based on aqueous-phase
3-31
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Volume 1
Section 3.0
emissions exceed physical limitations on
the aqueous phase, such as the soil
saturation concentration or solubility.
These are discussed below.
Most chemicals are better able to
volatilize from an aqueous medium than
from an organic medium; therefore, for
most chemicals, the aqueous-phase
emission rates are considerably higher
than organic-phase emission rates.
However, for a few chemicals (most
notably formaldehyde), the organic-
phase emissions are higher than the
aqueous-phase emissions and protective
waste concentrations based on organic-
phase emissions would be lower than
protective waste concentrations based on
aqueous-phase emissions. When this is
the case, the results based on aqueous-
phase emissions are footnoted to indicate
this. This does not invalidate the
aqueous-phase results, as that is still the
most likely waste matrix.
Some of the backcalculated waste
concentrations based on aqueous-phase
emissions exceed the soil saturation
concentration or solubility under
standard conditions. These are the
theoretical maximum possible aqueous-
phase concentration in soil or water,
respectively; once this is exceeded, free
(organic-phase) product will occur in the
soil or wastewater. In tanks, free organic
phase product will either sink, yielding
aqueous-phase emissions from a
concentration equal to the solubility, or float on the surface, yielding emissions from the organic
phase at a concentration of pure component. The soil saturation concentration and solubility
under standard temperature and pH conditions (20-25 C and neutral pH) have been estimated for
each chemical in the analysis, but these are somewhat site- and waste-specific values. Therefore,
a backcalculated concentration may exceed them in some situations but not in others. See
Section 7.10.2 of Volume II for details on how the soil saturation concentration and solubility
were estimated. When the backcalculated concentration based on aqueous-phase emissions
exceeded the typical soil saturation concentration or solubility calculated for this analysis, the
result was footnoted to indicate whether pure component (i.e., a concentration of 106 mg/kg or
Modifications to Methodology for Lead. Human health
risk assessment for lead is unique. Instead of developing an
RfC in the traditional manner, all identified sources of lead
exposure (including background) are used to predict blood
lead (PbB) levels in the exposed individuals. The predicted
PbB levels are compared to a target PbB. PbB levels have
long been used as an index of body lead burdens and as an
indicator of potential health effects.
The Integrated Exposure Uptake Biokinetic Model
(IEUBK) (U.S. EPA, 1994a) was developed to predict PbB
levels for an individual child or a population of children.
The model was specifically designed to evaluate lead
exposure in young children (birth to 7 years of age) because
this age group is known to be highly sensitive to lead
exposure. Therefore, only two receptors were modeled for
lead: children aged 0 to 3 years and 3 to 7 years. Adults
(including workers) and older children were excluded from
the analysis for lead because those age groups are considered
less sensitive to lead than 0- to 7-year-olds (and, in fact, the
pharmacokinetic relationships in the IEUBK model are only
valid for 0- to 7-year-olds).
For this analysis, the IEUBK model was used to identify
air concentrations that would result in a less than 5 percent
probability of having a PbB level higher than the target
PbB. That concentration in air was then used in place of an
RfC in the calculations. Because the IEUBK model cannot
be run in a backcalculation mode, different air
concentrations were modeled until one was found that
satisfied the 95 percent protection level desired. A target
blood lead level of 10 ug/dL was selected because that level
has been identified as a level of concern by the Centers for
Disease Control (CDC) (U.S. EPA, 1994a).
The IEUBK model inputs are summarized in Volume II.
They are inhalation rate, body weight, media concentrations
(including soil, indoor dust, water, and food), and indoor air
concentration as a percentage of outdoor air concentration.
3-32
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Volume 1 Section 3.0
mg/L) would result in a risk exceeding the target risk when modeled using organic-phase
emission rates.
3.3 Analysis of Variability and Uncertainty
The purpose of this section is to discuss the methods that are used in this study to capture
variability and uncertainty. Variability and uncertainty are discussed separately because they are
fundamentally different.
This discussion describes the treatment of variability in some parameters used to describe
human receptors and their behavior. Treatment of variability using a Monte Carlo simulation
forms the basis for the risk distributions. Uncertainty necessitates the use of assumptions, default
values, and imputation techniques in this study. Table 3-4 presents the major categories of
variability and uncertainty and how they have been addressed in this study. The columns in the
table show scenario uncertainty, model uncertainty, parameter uncertainty, and parameter
variability. The rows present the five main model components in the analysis: source
characterization, the emissions model, the dispersion model, the exposure model, and the risk
model.
3.3.1 Variability
Variability arises from true heterogeneity
in characteristics such as body weight
differences within a population or
differences in contaminant levels in the
environment.
Uncertainty represents lack of knowledge
about factors, such as the nature of adverse
effects from exposure to constituents, which
may be reduced with additional research.
In conducting a national risk assessment,
numerous parameters will vary across the nation.
Variability is often used interchangeably with the
term "uncertainty," but this is not strictly correct.
Variability is tied to variations in physical,
chemical, and biological processes and cannot be
reduced with additional research or information.
Although variability may be known with great
certainty (e.g., age distribution of a population
may be known and represented by the mean age and its standard deviation), it cannot be
eliminated and needs to be treated explicitly in the analysis. Spatial and temporal variability in
parameter values used to model exposure and risk account for the distribution of risk in the
exposed population.
In planning this analysis, it was important to specifically address as much of the
variability as possible, either directly in the Monte Carlo analysis or through disaggregation of
discrete parts of the analysis. For example, use of a refined receptor grid accounts for spatial
variability in concentrations around an WMU. Variability in WMU characteristics is accounted
for using a large database of individual WMUs that represent the range of possible WMU
characteristics.
3.3.2 Uncertainty
Uncertainty is a description of the imperfection in knowledge of the true value of a
particular parameter. In contrast to variability, uncertainty is reducible by additional information
3-33
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Volume 1
Section 3.0
Table 3-4. Summary of Variability and Uncertainty in the Study
Scenario
Uncertainty
Model
Uncertainty
Parameter
Uncertainty
Parameter Variability
Source
Characterization
Ancillary site
operations
not
addressed
(e.g.,
emissions
from truck
traffic or
unloading
operations)
Quality of survey data not
addressed (e.g., age and
representativeness of
data, missing data)
Imputation of parameter
values not directly
surveyed based on
statistical inference using
data for similar WMUs
Facility-specific location,
waste volume,
dimensions, engineering
design parameters used
to address variability in
WMU parameters
Biodegradtion variations
with site-specific factors
not addressed
Emissions Model Variations in
operation
practices not
addressed
Instantaneous
release model
used for acute
and subchronic
peak releases
Competing
release
mechanisms
(e.g., runoff,
erosion, leaching)
not addressed
Dependencies of
biodegradation, volatility,
and temperature
addressed through
sensitivity analysis and
use of seasonal
temperature variations
Differences in
biodegradation rates
between soil and
aqueous systems not
addressed
Facility-specific locations
and meteorology used to
address variability in
WMU parameters
Dispersion
Model
Model error
increased by
about 2% by not
using wet
deposition/depleti
on option
Photochemical
reactions and
degradation not
addressed
30-day and 1-day
averages used for
subchronic and
acute exposures,
respectively
Sensitivity analyses
conducted on a number
of parameters including
shape and orientation of
WMU, meteorologic data,
and receptor grid
29 meteorologic stations
used to represent climate
regions
14 surface areas used to
represent distribution of
surface area for landfills,
LAUs
29 surface areas/ heights
combinations used for
wastepiles
33 surface areas/height
combinations used for
tanks
Exposure Model
Indirect
exposures
not
addressed
Sensitivity analysis
conducted for receptor
grid
16 receptor locations at
each distance used in
Monte Carlo analysis
Exposure factor
distributions developed
and used in Monte Carlo
analysis
Risk Model
Health benchmark
uncertainty not addressed
(e.g., high to low dose
extrpolation, animal to
human extrapolation)
Variabilility in individual
dose response not
addressed
3-34
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Volume 1 Section 3.0
gathering or analysis activities (better data, better models). EPA typically classifies the major
areas of uncertainty in risk assessments as scenario uncertainty, model uncertainty, and parameter
uncertainty. Scenario uncertainty refers to missing or incomplete information needed to fully
define exposure and dose. Model uncertainty is a measure of how well the model simulates
reality. Finally, parameter uncertainty is the lack of knowledge regarding the true value of a
parameter that is used in the analysis. While some aspects of uncertainty were directly addressed
in the analysis, much of the uncertainty associated with this analysis could only be addressed
qualitatively.
Sources of scenario uncertainly include the assumptions and modeling decisions that are
made to represent an exposure scenario. Because we lack information or resources to define and
model actual exposure conditions, uncertainty is introduced into the analysis. Despite the
complexity of this analysis, it was necessary to exclude or simplify actual exposure conditions.
For example, this analysis only addresses inhalation exposures; indirect exposure pathways were
excluded. Professional judgement, often coupled with using the results of sensitivity analysis, is
used to decide which parameters to include in describing exposure conditions and behaviors.
These judgements are imperfect and uncertainty is introduced.
To reduce model uncertainty, EPA generally selected models that are considered state-of-
the-art. Model uncertainty is associated with all models used in all phases of a risk assessment.
These include the animal models used as surrogates for testing human carcinogenicity, dose-
response models used in extrapolations, and computer models used to predict the fate and
transport of chemicals in the environment. Computer models are simplifications of reality,
requiring exclusion of some variables that influence predictions but cannot be included in models
due either to increased complexity or to a lack of data on a particular parameter. The risk
assessor needs to consider the importance of excluded variables on a case-by-case basis because
a given variable may be important in some instances and not in others. A similar problem can
occur when a model that is applicable under average conditions is used when conditions differ
from the average. In addition, choosing the correct model form is often difficult when
conflicting theories seem to explain a phenomenon equally well. Modeling uncertainty is not
addressed directly in this study but is discussed qualitatively.
Parameter uncertainty occurs when (1) there is a lack of data about the parameters used in
the equations, (2) the data that are available are not representative of the particular instance being
modeled, or (3) parameter values cannot be measured precisely and/or accurately either because
of equipment limitations or because the quantity being measured varies spatially or temporally.
Random, or sample errors, are a common source of parameter uncertainty that is especially
critical for small sample sizes. More difficult to recognize are nonrandom or systematic errors
that result from bias in sampling, experimental design, or choice of assumptions.
3-35
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Volume I Section 4.0
4.0 Summary of Risk Assessment Results
This section presents an overview of the results of the risk analysis that evaluated the
direct inhalation risks from waste management unit (WMU) emissions. These results present
waste concentration levels (Cw's) that protect 90 percent of receptors at distances of 25, 150, and
1,000 m from the edge of the WMU across 90 percent of the sites (90/90 protection levels) at a
risk level of 10"5 or an HQ of 1. This subset of the results was selected for presentation purposes
only and does not imply that these are the results that would be used for an air characteristic. The
detailed results that are summarized here, as well as results for alternative risk levels, additional
distances, and additional protection levels, are presented in Volume III, Results, on CD-ROM.
4.1 Overview of Results
The most protective (i.e., lowest) 90/90 Cw values for adults across all WMUs ranged
from 0.005 ppm to 1 million ppm across all chemicals modeled. The lowest value, 0.005 ppm,
was for 2,3,7,8-TCDD in tanks. It should be noted that this value exceeds TCDD's solubility
limit (0.00002 ppm) at a neutral pH and temperature of 25°C. As discussed in Section 3.2.4.3,
the solubility limit (or soil saturation concentration for land-based units) is a site-specific value,
as it varies with pH and temperature. Due to this uncertainty, all the results in this report are
shown with the solubility or soil saturation concentration at neutral pH and a temperature of 20-
25 °C only for comparison purposes. The value for the next lowest chemical
(Nitrosodiethylamine) was 0.1 ppm. Chemicals with a Cw of 1 million ppm did not have any
concentration that would meet the specified risk level of 10"5 or HQ =1.
Figures 4-1 through 4-6 show the number of chemicals at a receptor distance of 150 m
with Cw in each order of magnitude range from 0.001 to 1 million ppm for aerated treatment
tanks, nonaerated treatment tanks, storage tanks, landfills, LAUs, and wastepiles, respectively.
For tanks and landfills, only chronic exposures were modeled, and these results are shown. For
LAUs and wastepiles, subchronic and acute results are also shown. Of the 104 chemicals
modeled,1 over half of those less then 1 million ppm fall in the 10 to 10,000 ppm range for tanks
and in the 100 to 100,000 ppm range for land-based units. From Figures 4-1 and 4-2 it appears
that at least 7 of the 105 chemicals in this study may present a significant potential risk via
inhalation at very low concentrations (i.e., <1 ppm) when managed in treatment tanks, and
another 28 may be of concern at relatively low concentrations (i.e., < 100 ppm). Figures 4-3 to
4-6 suggest that few chemicals are of concern at low levels (e.g. < 100 ppm) when managed in
other WMUs.
1 Note that 1 chemical of the original 1053,4-dimethylphenolwas addressed, but risks could not be
quantified because data were inadequate to develop a health benchmark for it.
4-1
-------
Volume I
Section 4.0
> 1,000,000
100,000-1,000,000
0.001 -0.01
10 15 20
Number of chemicals
25
30
Figure 4-1. Histogram of most protective 90/90 Cw for aerated treatment tanks.
Q.
a.
o
> 1,000,000
100,000-1,000,000
10,000-100,000
1,000-10,000
100-1,000
10-100
1 -10
0.1 -1
0.01 -0.10
0.001 -0.01
10 15 20
Number of chemicals
25
30
Figure 4-2. Histogram of most protective 90/90 Cw for
nonaerated treatment tanks.
4-2
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Volume I
Section 4.0
> 1,000,000
100,000-1,000,000
10,000-100,000
1,000-10,000
Q.
a.
o
0.01 -0.1
0.001 -0.010
10 15
Number of chemicals
20
25
Figure 4-3. Histogram of most protective 90/90 Cw for storage tanks.
> 1 ,000,000
100,000-1,000,000
10,000-100,000
1,000-10,000
E 100-1,000
Q.
O
10-100
1 -10
0.1 -10
0.01 -0.10
0.001 -0.010
0
10 15
Number of chemicals
20
25
Figure 4-4. Histogram of most protective 90/90 Cw for landfills.
4-3
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Volume I
Section 4.0
> 1,000,000°
100,000-1,000,000
10,000-100,000
1,000-10,000
i" 100-1,000
Q.
a.
5 10-100
0
1 -10
0.1 -10
0.01 -0.10
0.001 -0.010
^^
i y
p
0 5 10 15 20 25
Number of chemicals
Chronic nSubchronic n Acute
Figure 4-5. Histogram of most protective 90/90 Cw for LAUs.
> 1,000,000
100,000-1,000,000
10,000-100,000
1,000-10,000
E 100-1,000
Q.
Q.
V 10-100
0
1-10°
0.1-10
0.01 -0.1o
0.001 -0.01o
i 1 1
in
1 H
1 1 1
. |2
^^^^^^5
^
1 1
0 2 4 6 8 10 12 14 16 18 20
Number of chemicals
Chronic nSubchronic n Acute
Figure 4-6. Histogram of most protective 90/90 Cw for wastepiles.
4-4
-------
Volume I Section 4.0
Tables 4-1 through 4-6 summarize the chronic 90/90 values for all chemicals and
receptors for landfills, land application units, wastepiles, aerated treatment tanks, nonaerated
treatment tanks, and storage tanks, respectively. These tables show the 90/90 Cw for adult
residents and for child residents age 0 to 3 years at the start of exposure for chronic exposures at
a range of distances. The acute and subchronic results are summarized later in the section and
are shown in Tables 4-9 through 4-12. Acute and subchronic exposures were modeled for LAUs
and wastepiles to capture the potential peaks in emissions immediately after episodic loading
events.
Generally speaking, volatile emissions far exceeded particulate emissions for volatile and
semivolatile chemicals, accounting for over 98 percent of total emissions in most cases.
Therefore, the particulate emissions are important for metals (except mercury), which do not
volatilize, and much less important for the other chemicals included in this study.
The results appear to be closely associated with three primary factors: (1) the physical-
chemical properties and toxicity of the chemicals, (2) the WMU type, and (3) exposure factors.
The effects of each of these factors are discussed in sections 4.2 through 4.4 with respect to the
chronic results. A comparison of chronic, subchronic, and acute results follows in section 4.5.
Table 4-7 presents the physical-chemical properties and toxicity of each chemical. With
respect to the health benchmarks shown, note that higher CSFs indicate greater toxicity and
lower RfCs reflect greater toxicity.
4.2 Effect of Chemical Properties and Health
Benchmarks
The most important factors affecting the results are the
physical-chemical properties and toxicity of the chemical.
These chemical properties, which include solubility, Henry's
law constant (which reflects the tendency to volatilize from
, .... .. . . . Butadiene, 1,3-
water), and biodegradation rate, interact in a complex manner
Ten Chemicals with Highest
Risk Across All WMU Types
2,3,7,8-TCDD
Nitrosodiethylamine
Nitrosodi-n-butylamine
Acrolein
Nitropropane, 2-
Hexachlorocyclopentadiene
Mercury
Vinyl chloride
Ethylene Dibromide
to produce the final result. A chemical must both be emitted
in significant quantities and be fairly toxic to result in high
risk (and therefore have a low Cw). A chemical may be highly
toxic, but if it is not emitted in significant quantities, it will
result in little risk. Because of this, it appears that the
physical-chemical properties seem to be more important for chemicals with low risk, while the
toxicity seems to be more important for chemicals with high risk.
Chemicals with the highest risk (see box), and so lowest Cw, appear to be driven by
toxicity. These top-10 chemicals are not the most volatile chemicals of the 104; 2 of them,
hexachlorocyclopentadiene and 2,3,7,8,-TCDD, are even defined as semivolatiles. Seven of the
10 chemicals are fairly toxic carcinogens with cancer slope factors greater than most of the
carcinogens evaluated for this study. The 3 noncarcinogens are also quite toxic and have very
low RfCs, among the 10 lowest in this study. The RfCs for these three constituents were equal to
or less than 3E-4 mg/m3. It should be noted that 2 of the 10 chemicals with the highest risk have
4-5
-------
Table 4-1. Chronic 90/90 Cw at 25 m to 1,000 m, Risk = 10 5/HQ = 1 for Landfills (mg/kg)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
107-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Acrylic acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71-43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
7440-47-3 Chromium VI
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Metal
Adult Resident*
25m
4E+03 °
no risk
7E+03
1E+00
150m
3E+04 °
no risk
6E+04
1E+01
1000m
6E+05 a'°
no risk
b
no risk
2E+02
NM
NM
7E+01
1E+01
6E+02
1E+02
1E+04
2E+03 a
NM
5E+03
2E+05
3E+02
4E+04
no risk
2E+03 a
no risk
no risk
5E+04 a
NM
NM
9E+03
4E+02
2E+04 a
1E+00
1E+04
1 E+04 a
1E+02
1E+02
2E+03
5E+02
9E+01
8E+04
3E+03
2E+05
9E+00
1E+05
9E+04
9E+02
1E+03
1 E+04 a
5E+03 a
8E+02
no risk
7E+04 a
b
no risk
2E+02
no risk
no risk
2E+04 a
3E+04 a
3E+05
1E+05
2E+04 a
NM
2E+03
2E+04
4E+05
25m
3E+03
6E+01
4E+03
2E+02
8E+03
3E+02
2E+04
9E-01
1E+04
Child Resident 0-3
150m
3E+04 °
same as adult
same as adult
same as adult
NM
NM
5E+02
same as adult
NM
4E+04
same as adult
2E+03 a
NM
NM
7E+04
3E+03
a b
1E+05
9E+00
9E+04
yr
1000m
5E+05 a'°
1E+04
9E+05
4E+04 a
no risk
6E+04 a
b
no risk
2E+02
no risk
same as adult
1E+02
5E+02
8E+01
2E+03
8E+02
same as adult
same as adult
4E+03 a
7E+02
NM
1E+04
2E+04 a
9E+04
1 E+04 a
3E+05
csa,
(mg/kg)
3.3E+05
2.3E+05
2.3E+05
5.0E+04
1 .5E+05
2.4E+05
1 .8E+04
1 .7E+03
1 .OE+04
1 .OE+06
1 .OE+06
1 .8E+03
2.4E+02
1 .5E+02
1 .OE+06
6.3E+03
4.5E+03
1.1E+03
1 .OE+06
1 .3E+03
2.7E+03
1 .8E+03
2.0E+03
2.7E+03
5.7E+03
2.2E+04
1 .OE+06
o'
s
(continued)
-------
Table 4-1. (continued)
CAS Name
7440-48-4 Cobalt
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1,2-
106-46-7 Dichlorobenzene, 1,4-
75-71-8 Dichlorodifluoromethane
107-06-2 Dichloroethane, 1,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1 ,2-
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
106-88-7 Epoxybutane, 1,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21 -8 Ethylene oxide
50-00-0 Formaldehyde
98-01-1 Furfural
87-68-3 Hexachloro-1,3-butadiene
118-74-1 Hexachlorobenzene
Group
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Semi
Adult Resident*
25m
3E+03
150m
3E+04
1000m
6E+05
NM
6E+03
6E+00
5E+04
5E+04
2E+05
2E+03 a
1E+02
2E+01
2E+02
1E+02
1E+02
5E+04
5E+01
4E+05
4E+05
b
no risk
2E+04 a
1E+03
2E+02
2E+03
1E+03
1E+03
no risk
9E+02
b
no risk
no risk
b
no risk
3E+05
2E+04 a
4E+03 a
3E+04 a
2E+04 a
3E+04 a
NM
NM
2E+05 °
b,c
no risk
b,c
no risk
NM
1E+04
1E+03
1 E+05 °
3E+05 a'°
9E+04
5E+01
8E+04 a
1E+04
no risk
b,c
no risk
7E+05
4E+02
no risk
2E+05 a
no risk
b,c
no risk
b
no risk
9E+03 a
NM
4E+01 °
5E+03 °
3E+04 a
4E+02 °
4E+04 °
3E+05 a
7E+03 °
8E+05 a'°
no risk
NM
NM
Child Resident 0-3 yr
25 m 150 m 1000 m
same as adult
NM
same as adult
same as adult
4E+04 4E+05 no risk
same as adult
same as adult
same as adult
1 E+02 9E+02 2E+04 '
2E+01 2E+02 4E+03 '
same as adult
1 E+02 9E+02 2E+04 '
1 E+02 1 E+03 2E+04 '
NM
NM
same as adult
NM
8E+03 7E+04 no risk
same as adult
same as adult
same as adult
same as adult
4E+01 4E+02 8E+03 '
NM
4E+01 ° 3E+02 ° 6E+03 °
4E+03 ° 4E+04 ° 7E+05 °'°
same as adult
NM
NM
(mg/kg)
1 .OE+06
5.2E+03
1 .9E+03
1 .6E+04
1 .8E+03
2.2E+03
1 .OE+03
1 .2E+03
3.4E+03
2.7E+03
2.2E+03
2.2E+03
2.2E+03
4.8E+02
2.1 E+02
2.3E+05
3.3E+02
1 .6E+04
1 .7E+04
2.3E+05
2.3E+05
1 .3E+03
3.1 E+03
2.3E+05
8.9E+04
1 .3E+05
2.7E+04
1 .OE+03
2.3E+04
o'
s
(continued)
-------
oo
Table 4-1. (continued)
CAS Name
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
110-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
924-16-3 Nitrosodi-n-butylamine
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
Group
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Vol
Vol
Semi
Semi
Vol
Adult Resident*
25m
150m
1000m
NM
4E+04
3E+05
b
no risk
NM
6E+05
2E+04
2E+02 a
no risk
1 E+04 °
3E+04 °
9E+01
4E+02
1 E+05 a
1 E+04 a
7E+04 a
2E+05 a
no risk
1E+05
1E+03
no risk
1 E+05 °
2E+05 °
8E+02
4E+03 a
no risk
9E+04 a
6E+05
no risk
no risk
no risk
3E+04
no risk
no risk
b,c
no risk
1 E+04 a
7E+04 a
no risk
b
no risk
b
no risk
no risk
NM
4E+03
3E+04 a
6E+05
NM
2E+04 a
7E+02 °
2E+03 a
9E+04
1E+05
6E+03 °
1E+04
8E+05
no risk
1 E+05 °
2E+05
no risk
NM
3E+00
6E+00
6E-01
2E+01
5E+01
6E+00
4E+02
1E+03
1E+02
NM
NM
1 E+03 °
1 E+04 °
3E+05 a'°
Child Resident 0-3 yr
25 m 150 m 1000 m
NM
3E+04 3E+05 no risk
NM
2E+05 no risk no risk
same as adult
same as adult
same as adult
same as adult
same as adult
same as adult
4E+02 3E+03 ' 6E+04 '
same as adult
same as adult
same as adult
same as adult
NM
3E+03 3E+04 6E+05
NM
same as adult
6E+02 ° 5E+03 ° 1 E+05 °
same as adult
8E+04 7E+05 no risk
NM
2E+00 2E+01 4E+02
5E+00 4E+01 9E+02
6E-01 5E+00 1 E+02
NM
NM
1 E+03 ° 1 E+04 ° 2E+05 ''"
(mg/kg)
2.1 E+03
2.6E+03
6.1 E+03
1 .OE+06
1 .OE+06
2.6E+01
2.3E+05
2.3E+05
2.3E+05
5.7E+03
1 .9E+03
5.4E+04
6.0E+03
5.5E+03
2.6E+04
4.0E+01
4.6E+03
2.3E+05
6.4E+02
2.3E+05
3.8E+02
1 .OE+06
1 .3E+03
4.6E+03
2.1 E+03
2.3E+04
3.3E+04
1 .4E+03
1.1 E+05
o'
s
(continued)
-------
Table 4-1. (continued)
CAS Name
110-86-1 Pyridine
100-42-5 Styrene
1746-01-6 TCDD, 2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1 ,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01 -6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1 330-20-7 Xylenes (total)
Group
Vol
Vol
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Adult Resident*
25m
3E+03
1E+05
150m
2E+04
9E+05
1000m
4E+05 a
b
no risk
NM
8E+02
2E+02
4E+03 a
2E+04 a
7E+03 a
2E+03
3E+04
2E+05
1E+05
4E+04 a
7E+05
no risk
NM
4E+05
b
no risk
b
no risk
NM
3E+04 a
3E+02
2E+03
1 E+04 a
1E+03
2E+04
1 E+04 a
8E+00
4E+04
2E+05
3E+03
1 E+04 a
9E+04
8E+03
2E+05
8E+04 a
7E+01
3E+05
b
no risk
6E+04 a
3E+05
no risk
2E+05 a
no risk
no risk
1E+03
no risk
Child Resident 0-3 yr
25 m 150 m 1000 m
same as adult
same as adult
NM
7E+02 6E+03 1 E+05
2E+02 2E+03 4E+04 '
3E+03 3E+04 6E+05
same as adult
NM
same as adult
NM
same as adult
3E+02 3E+03 6E+04 '
2E+03 1 E+04 3E+05
same as adult
same as adult
same as adult
same as adult
7E+00 6E+01 1 E+03
same as adult
Csat
(mg/kg)
2.6E+05
1 .5E+03
3.8E-01
2.8E+03
4.7E+03
5.9E+02
1 .7E+03
5.9E+03
2.1 E+03
1 .6E+04
2.7E+03
3.8E+03
3.4E+03
3.3E+03
2.1 E+04
1 .OE+06
5.3E+03
1 .8E+03
1 .5E+03
NM = Not modeled for land-based units.
no risk = the aqueous phase result exceeded ~\ million parts per million (1,000,000 mg/kg or mg/L).
* For lead only, this column contains results for Child Resident 3-7 years.
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2A.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk is less than 1 E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
0 Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2A.3 for more details.
o'
s
-------
Table 4-2. Chronic 90/90 Cw at 25 m to 1,000 m, Risk = 10 5/HQ = 1 for Land Application Units (mg/kg)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
107-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Acrylic acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71-43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1 ,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Adult Resident*
25m
3E+03
no risk
7E+03
1E+00
150m
9E+03 °
b, b,c
c no risk
2E+04
4E+00
1000m
1 E+05 °
i b'°
no risk
2E+05
4E+01
NM
NM
5E+01
1E+01
2E+02
4E+01
2E+03
5E+02
NM
9E+02
4E+04
1E+02
3E+03
1E+05
5E+02
3E+04
no risk
5E+03
NM
NM
2E+03
1E+02
7E+03
1E+00
2E+03
9E+03
5E+01
1E+02
7E+02
2E+02
3E+01
5E+03
4E+02
3E+04 a
4E+00
7E+03
3E+04
2E+02
3E+02
2E+03
7E+02
1E+02
5E+04
4E+03
2E+05
4E+01
6E+04
3E+05
1E+03
3E+03
2E+04
6E+03
1E+03
NM
Child
25m
4E+03 °
5E+01
1E+03
2E+02
2E+03
1E+02
8E+03
1E+00
2E+03
6E+01
2E+02
4E+01
Resident 0-3 yr
150m
1 E+04 °
same as adult
same as adult
same as adult
NM
NM
2E+02
same as adult
NM
3E+03
same as adult
6E+02
NM
NM
6E+03
4E+02
3E+04
4E+00
8E+03
same as adult
2E+02
same as adult
same as adult
8E+02
1E+02
1000m
1 E+05 °
2E+03
3E+04
5E+03
5E+04
5E+03
3E+05
4E+01
7E+04
2E+03
7E+03
1E+03
NM
Csa,
(mg/kg)
3.3E+05
2.3E+05
2.3E+05
5.0E+04
1 .5E+05
2.4E+05
1 .8E+04
1 .7E+03
1 .OE+04
1 .OE+06
1 .OE+06
1 .8E+03
2.4E+02
1 .5E+02
1 .OE+06
6.3E+03
4.5E+03
1.1E+03
1 .OE+06
1 .3E+03
2.7E+03
1 .8E+03
2.0E+03
2.7E+03
5.7E+03
2.2E+04
o'
s
(continued)
-------
Table 4-2. (continued)
CAS Name
7440-47-3 Chromium VI
7440-48-4 Cobalt
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1,2-
106-46-7 Dichlorobenzene, 1,4-
75-71-8 Dichlorodifluoromethane
107-06-2 Dichloroethane, 1,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1 ,2-
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
106-88-7 Epoxybutane, 1,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21 -8 Ethylene oxide
50-00-0 Formaldehyde
Group
Metal
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Adult Resident*
25m
3E+02
8E+02
150m
1E+03
3E+03
1000m
9E+03
2E+04
NM
2E+04
5E+00
4E+04
6E+04
2E+05
2E+03
3E+01
1E+01
8E+01
8E+01
9E+01
7E+04
2E+01
b b
1E+05
b b
2E+05
7E+05
7E+03 a
1E+02
5E+01
2E+02
3E+02
3E+02
5E+05
2E+02
no risk
b
no risk
no risk
7E+04
1E+03
5E+02
2E+03
3E+03
3E+03
NM
NM
1E+05
° 4E+05 "
i b'°
no risk
NM
5E+03
1E+03
1E+05
3E+05
4E+04
2E+01
2E+04
4E+03
° 3E+05 "
a, a,c
8E+05
1E+05
6E+01
2E+05
4E+04
i b'°
no risk
no risk
no risk
6E+02
NM
3E+01
4E+03
1E+02
1E+04
1E+03
1 E+05 a'°
Child Resident 0-3 yr
25m 150m 1000m
4E+02 1 E+03 1 E+04
same as adult
NM
same as adult
same as adult
4E+04 1 E+05 no risk
same as adult
same as adult
same as adult
4E+01 2E+02 1 E+03
2E+01 5E+01 5E+02
same as adult
9E+01 3E+02 3E+03
1 E+02 3E+02 3E+03
NM
NM
same as adult
NM
6E+03 2E+04 2E+05
same as adult
same as adult
same as adult
same as adult
2E+01 7E+01 7E+02
NM
4E+01 1 E+02 1 E+03
5E+03 ° 2E+04 ° 2E+05 ''"
Csat
(mg/kg)
1 .OE+06
1 .OE+06
5.2E+03
1 .9E+03
1 .6E+04
1 .8E+03
2.2E+03
1 .OE+03
1 .2E+03
3.4E+03
2.7E+03
2.2E+03
2.2E+03
2.2E+03
4.8E+02
2.1 E+02
2.3E+05
3.3E+02
1 .6E+04
1 .7E+04
2.3E+05
2.3E+05
1 .3E+03
3.1 E+03
2.3E+05
8.9E+04
1 .3E+05
(continued)
o'
s
-------
Table 4-2. (continued)
CAS Name
98-01-1 Furfural
87-68-3 Hexachloro-1,3-butadiene
118-74-1 Hexachlorobenzene
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
110-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
924-16-3 Nitrosodi-n-butylamine
Group
Vol
Semi
Semi
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Vol
Adult Resident*
25m
4E+03
150m
1E+04
1000m
1E+05
NM
NM
NM
7E+03
b b
2E+04
2E+05
NM
1E+05
4E+03
2E+01
no risk
1E+04
2E+04
8E+01
4E+02
2E+05
1E+04
5E+04
1E+05
5E+05
1E+04
5E+01
b, b,c
c no risk
4E+04
5E+04
3E+02
1E+03
6E+05 a
5E+04 a
a b
2E+05
a b
3E+05
no risk
1E+05
5E+02
no risk
4E+05 a'°
7E+05 a'°
3E+03
1E+04
no risk
4E+05
no risk
b
no risk
NM
2E+03
8E+03
8E+04
NM
7E+03
2E+02
3E+03
2E+04
a b
2E+04
6E+02
8E+03 "
5E+04
2E+05
7E+03
9E+04
5E+05
NM
8E-01
4E+00
3E+00
1E+01
4E+01
1E+02
Child Resident 0-3 yr
25m 150m 1000m
same as adult
NM
NM
NM
8E+03 2E+04 2E+05
NM
4E+04 1 E+05 no risk
same as adult
same as adult
same as adult
same as adult
same as adult
same as adult
4E+02 1 E+03 1 E+04
same as adult
same as adult
same as adult
same as adult
NM
2E+03 9E+03 9E+04
NM
same as adult
2E+02 7E+02 7E+03
same as adult
2E+04 6E+04 5E+05
NM
9E-01 4E+00 4E+01
4E+00 1 E+01 1 E+02
Csat
(mg/kg)
2.7E+04
1 .OE+03
2.3E+04
2.1 E+03
2.6E+03
6.1 E+03
1 .OE+06
1 .OE+06
2.6E+01
2.3E+05
2.3E+05
2.3E+05
5.7E+03
1 .9E+03
5.4E+04
6.0E+03
5.5E+03
2.6E+04
4.0E+01
4.6E+03
2.3E+05
6.4E+02
2.3E+05
3.8E+02
1 .OE+06
1 .3E+03
4.6E+03
2.1 E+03
to
o'
s
(continued)
-------
Table 4-2. (continued)
CAS Name
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
110-86-1 Pyridine
100-42-5 Styrene
1746-01-6 JCDD,2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1 ,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01 -6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1 330-20-7 Xylenes (total)
Group
Vol
Semi
Semi
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Adult Resident*
25m
3E-01
150m
8E-01
1000m
7E+00
NM
NM
1E+03
5E+03
3E+05
4E+03
1E+04
9E+05
4E+04
2E+05
no risk
NM
3E+02
1E+02
1E+03
1E+04
1E+03
4E+02
5E+03 °
4E+04 "
1E+04
5E+03
4E+04
4E+05
NM
4E+05
b b
no risk
b
no risk
NM
2E+04
8E+01
5E+02
9E+03
2E+02
6E+03
1E+04
7E+00
2E+04
a b
5E+04
2E+02
2E+03
3E+04
7E+02
2E+04
4E+04 °
2E+01
b b
6E+04
4E+05
2E+03
2E+04
3E+05
6E+03
2E+05
4E+05
2E+02
6E+05
Child Resident 0-3 yr
25m 150m 1000m
3E-01 1 E+00 8E+00
NM
NM
1 E+03 5E+03 5E+04
same as adult
same as adult
NM
3E+02 1 E+03 1 E+04
1 E+02 5E+02 5E+03
2E+03 6E+03 5E+04
same as adult
same as adult
NM
same as adult
1 E+02 3E+02 3E+03
6E+02 2E+03 2E+04
same as adult
same as adult
same as adult
same as adult
8E+00 3E+01 3E+02
same as adult
Csat
(mg/kg)
2.3E+04
3.3E+04
1 .4E+03
1.1E+05
2.6E+05
1 .5E+03
3.8E-01
2.8E+03
4.7E+03
5.9E+02
1 .7E+03
5.9E+03
2.1 E+03
1 .6E+04
2.7E+03
3.8E+03
3.4E+03
3.3E+03
2.1 E+04
1 .OE+06
5.3E+03
1 .8E+03
1 .5E+03
NM = Not modeled for land-based units.
no risk = the aqueous phase result exceeded ~\ million parts per million (1,000,000 mg/kg or mg/L).
* For lead only, this column contains results for Child Resident 3-7 years.
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk is less than 1 E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
0 Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2A.3 for more details.
o'
s
-------
Table 4-3. Chronic 90/90 Cw at 25 m to 1,000 m, Risk = 10 5/HQ = 1 for Wastepiles (mg/kg)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
107-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Acrylic acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71-43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1 ,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Adult Resident*
25m
8E+03
no risk
2E+04
3E+00
150m
6E+04
no risk
1E+05
2E+01
1000m
i a'°
no risk
no risk
no risk
5E+02
NM
NM
1E+02
3E+01
1E+03
2E+02
2E+04
4E+03
NM
7E+02
3E+04
6E+02
6E+03
3E+05
4E+03
1E+05
no risk
9E+04
NM
NM
1E+03
7E+02
8E+04
1E+00
2E+03
2E+04
2E+02
3E+02
4E+03
2E+03
1E+02
1E+04
5E+03
6E+05
1E+01
1E+04
1E+05
1E+03
2E+03
3E+04
1E+04
9E+02
2E+05
1E+05
no risk
2E+02
3E+05
no risk
3E+04
4E+04
5E+05
3E+05
2E+04
NM
25m
9E+03
Child Resident 0-3
150m
7E+04
yr
1000m
i a'°
no risk
same as adult
same as adult
same as adult
NM
NM
1E+02
1E+03
2E+04 a
same as adult
NM
8E+02
7E+03
1E+05
same as adult
7E+02
5E+03
1E+05
NM
NM
1E+03
8E+02
9E+04
1E+00
2E+03
1E+04
6E+03
7E+05
1E+01
2E+04
3E+05
1E+05
no risk
2E+02
4E+05
same as adult
2E+02
1E+03
3E+04
same as adult
same as adult
2E+03
1E+02
2E+04
1E+03
4E+05
2E+04 a
NM
Csat
(mg/kg)
3.3E+05
2.3E+05
2.3E+05
5.0E+04
1 .5E+05
2.4E+05
1 .8E+04
1 .7E+03
1 .OE+04
1 .OE+06
1 .OE+06
1 .8E+03
2.4E+02
1 .5E+02
1 .OE+06
6.3E+03
4.5E+03
1.1E+03
1 .OE+06
1 .3E+03
2.7E+03
1 .8E+03
2.0E+03
2.7E+03
5.7E+03
2.2E+04
o'
s
(continued)
-------
Table 4-3. (continued)
CAS Name
7440-47-3 Chromium VI
7440-48-4 Cobalt
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1,2-
106-46-7 Dichlorobenzene, 1,4-
75-71-8 Dichlorodifluoromethane
107-06-2 Dichloroethane, 1,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1 ,2-
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
106-88-7 Epoxybutane, 1,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21-8 Ethylene oxide
50-00-0 Formaldehyde
Group
Metal
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Adult Resident*
25m
2E+02
6E+02
150m
2E+03
5E+03
1000m
5E+04
1E+05
NM
3E+04
1E+01
1E+05
2E+05
6E+05
3E+03
2E+02
3E+01
3E+02
3E+02
4E+02
2E+05
1E+02
9E+05
no risk
no risk
2E+04
1E+03
2E+02
2E+03
2E+03
3E+03
no risk
2E+03
no risk
no risk
no risk
4E+05
2E+04
5E+03
5E+04
5E+04
6E+04
NM
NM
4E+05 a'°
no risk
no risk
NM
2E+04
4E+03
3E+05 "
7E+05 a'°
3E+05
2E+02
1E+05
2E+04
no risk
no risk
no risk
1E+03
no risk
5E+05
no risk
no risk
no risk
3E+04
NM
8E+01
1E+04
6E+02
7E+04
1E+04
no risk
Child Resident 0-3 yr
25m 150m 1000m
3E+02 2E+03 5E+04
same as adult
NM
same as adult
same as adult
b b b
1 E+05 no risk no risk
same as adult
same as adult
same as adult
2E+02 1 E+03 3E+04
4E+01 3E+02 5E+03
same as adult
4E+02 3E+03 5E+04
4E+02 3E+03 6E+04
NM
NM
same as adult
NM
2E+04 1 E+05 no risk
same as adult
same as adult
same as adult
same as adult
2E+02 1 E+03 3E+04
NM
9E+01 7E+02 1 E+04
1 E+04 ° 8E+04 ° no risk ''"
Csat
(mg/kg)
1 .OE+06
1 .OE+06
5.2E+03
1 .9E+03
1 .6E+04
1 .8E+03
2.2E+03
1 .OE+03
1 .2E+03
3.4E+03
2.7E+03
2.2E+03
2.2E+03
2.2E+03
4.8E+02
2.1E+02
2.3E+05
3.3E+02
1 .6E+04
1 .7E+04
2.3E+05
2.3E+05
1 .3E+03
3.1 E+03
2.3E+05
8.9E+04
1 .3E+05
(continued)
o'
s
-------
Table 4-3. (continued)
CAS Name
98-01-1 Furfural
87-68-3 Hexachloro-1,3-butadiene
118-74-1 Hexachlorobenzene
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
110-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
924-16-3 Nitrosodi-n-butylamine
Group
Vol
Semi
Semi
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Vol
Adult Resident*
25m
4E+04 a
150m
3E+05 a
1000m
b
no risk
NM
NM
NM
2E+05
no risk
no risk
NM
1E+05
3E+03
2E+02
no risk
3E+04
5E+04
2E+02
5E+02
4E+05
3E+04
2E+05
5E+05
9E+05
3E+04
1E+03
no risk
2E+05
4E+05 "
1E+03
4E+03
no risk
2E+05
no risk
no risk
no risk
5E+05
3E+04
no risk
no risk
no risk
3E+04
8E+04
no risk
no risk
no risk
no risk
NM
6E+03
5E+04
no risk
NM
4E+04
8E+02
7E+03
1E+04
2E+05
6E+03
4E+04
1E+05
no risk
1E+05
8E+05
no risk
NM
5E+00
1E+01
4E+01
1E+02
8E+02
2E+03
Child Resident 0-3 yr
25m 150m 1000m
same as adult
NM
NM
NM
3E+05 no risk no risk
NM
3E+04 3E+05 no risk
same as adult
same as adult
same as adult
same as adult
same as adult
same as adult
6E+02 5E+03 9E+04
same as adult
same as adult
same as adult
same as adult
NM
7E+03 6E+04 no risk
NM
same as adult
9E+02 7E+03 1 E+05
same as adult
1 E+04 1 E+05 no risk
NM
6E+00 4E+01 9E+02
2E+01 1 E+02 2E+03
Csat
(mg/kg)
2.7E+04
1 .OE+03
2.3E+04
2.1E+03
2.6E+03
6.1E+03
1 .OE+06
1 .OE+06
2.6E+01
2.3E+05
2.3E+05
2.3E+05
5.7E+03
1 .9E+03
5.4E+04
6.0E+03
5.5E+03
2.6E+04
4.0E+01
4.6E+03
2.3E+05
6.4E+02
2.3E+05
3.8E+02
1 .OE+06
1 .3E+03
4.6E+03
2.1E+03
o'
s
(continued)
-------
Table 4-3. (continued)
CAS Name
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
110-86-1 Pyridine
100-42-5 Styrene
1746-01-6 TCDD, 2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1 ,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01 -6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1 330-20-7 Xylenes (total)
Group
Vol
Semi
Semi
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Adult Resident*
25m
9E-01
150m
7E+00
1000m
1E+02
NM
NM
3E+03
1E+04
5E+05
2E+04
7E+04
no risk
4E+05 a'°
. . "
no risk
no risk
NM
2E+03
7E+02
6E+03
5E+04
1E+04
6E+03
4E+04
4E+05
3E+05
1E+05
9E+05
no risk
NM
9E+05
. . "
no risk
. . °
no risk
NM
5E+04
4E+02
2E+03
2E+04
1E+03
4E+03
3E+04
9E+00
1E+05
4E+05
3E+03
2E+04
1E+05
1E+04
4E+04
2E+05
7E+01
7E+05
no risk
7E+04
4E+05
no risk
2E+05
8E+05
. . °
no risk
1E+03
no risk
Child Resident 0-3 yr
25m 150m 1000m
1 E+00 8E+00 2E+02
NM
NM
3E+03 ° 2E+04 ° 5E+05 ^
same as adult
same as adult
NM
2E+03 1 E+04 3E+05
8E+02 7E+03 1 E+05
6E+03 5E+04 no risk
same as adult
NM
same as adult
NM
same as adult
5E+02 4E+03 8E+04
3E+03 2E+04 4E+05
same as adult
same as adult
same as adult
same as adult
1 E+01 8E+01 2E+03
same as adult
Csat
(mg/kg)
2.3E+04
3.3E+04
1 .4E+03
1.1 E+05
2.6E+05
1 .5E+03
3.8E-01
2.8E+03
4.7E+03
5.9E+02
1 .7E+03
5.9E+03
2.1E+03
1 .6E+04
2.7E+03
3.8E+03
3.4E+03
3.3E+03
2.1 E+04
1 .OE+06
5.3E+03
1 .8E+03
1 .5E+03
NM = Not modeled for land-based units.
no risk = the aqueous phase result exceeded ~\ million parts per million (1,000,000 mg/kg or mg/L).
* For lead only, this column contains results for Child Resident 3-7 years.
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk is less than 1 E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
0 Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2A.3 for more details.
o'
s
-------
oo
Table 4-4. Chronic 90/90 Cw at 25 m - 1,000 m, Risk = 10 5/HQ = 1 for Aerated Treatment Tanks (mg/L)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
107-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Aery lie acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71-43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1 ,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
25m
7E+01
1E+05
3E+02
5E-02
5E+03
7E+02
2E+00
6E-01
9E+01
Adult Resident*
150m
4E+02
no risk
2E+03
3E-01
4E+04
5E+03 °
1E+01
4E+00
6E+02
1000m
9E+03
no risk
4E+04
6E+00
8E+05
1E+05
3E+02
9E+01
1E+04
NM
NM
4E+00
8E+03
2E+02
3E+01
5E+04
1E+03
6E+02
9E+05
2E+04
NM
3E+00
1E+02
5E-02
2E+01
6E+02
4E-01
4E+02
1E+04
8E+00
NM
4E+02
2E+00
4E+00
2E+01
3E+03 a
1E+01
3E+01
1E+02
6E+04
3E+02
6E+02
2E+03 a
Child
25m
8E+01
Resident 0-3 yr
150m 1000m
5E+02 1 E+04
same as adult
same as adult
same as adult
6E+03
4E+04 9E+05
same as adult
2E+00
1 E+01 3E+02
same as adult
same as adult
NM
NM
5E+00
9E+03
2E+02
3E+01 7E+02
5E+04 no risk
1 E+03 3E+04
NM
4E+00
1E+02
6E-02
2E+01 5E+02
7E+02 1 E+04
4E-01 9E+00
NM
same as adult
2E+00
2E+01 4E+02
same as adult
same as adult
Solubility
(mg/L)
1 .OE+06
1 .OE+06
1 .OE+06
2.1E+05
6.4E+05
1 .OE+06
7.4E+04
3.4E+03
3.6E+04
O.OE+00
O.OE+00
1 .8E+03
5.0E+02
2.5E-02
O.OE+00
6.7E+03
3.1 E+03
7.4E+02
O.OE+00
1 .2E+03
7.9E+02
1 .7E+03
4.7E+02
(continued)
o'
s
-------
Table 4-4. (continued)
CAS Name
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
7440-47-3 Chromium VI
7440-48-4 Cobalt
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1 ,2-
106-46-7 Dichlorobenzene, 1,4-
75-71-8 Dichlorodifluoromethane
107-06-2 Dichloroethane, 1,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1,2-
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
106-88-7 Epoxybutane, 1,2-
Group
Vol
Vol
Semi
Metal
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Vol
Vol
25m
4E+00
2E+00
3E+00
Adult Resident*
150m
2E+01
1E+01
2E+01
1000m
5E+02
2E+02
3E+02
NM
NM
4E+01
2E+02 a
8E-01
3E+02
2E+02 a
8E+02
1E+02
2E+00
5E-01
3E+00
1E+00
1E+00
6E+02
2E+02
1E+04
9E+01
3E+02
3E+01
3E+02
2E+03
4E+00
2E+03
1E+03
5E+03
8E+02 a
1E+01
4E+00
2E+01
8E+00
1E+01
4E+03
2E+03
9E+04
5E+02
2E+03
1E+02
5E+03
4E+04
9E+01
5E+04
3E+04
1E+05
2E+04 a
3E+02
9E+01
5E+02
2E+02
2E+02
8E+04
4E+04
b
no risk
1E+04
4E+04
3E+03
Child
25m
4E+00
2E+00
4E+02
2E+00
6E-01
1E+00
2E+00
8E+02
3E+02
1E+02
4E+02
Resident 0-3 yr
150m
2E+01
1E+01
same as adult
NM
NM
same as adult
same as adult
same as adult
2E+03
same as adult
same as adult
same as adult
1E+01
5E+00
same as adult
9E+00
1E+01
4E+03
2E+03
same as adult
6E+02
2E+03
1000m
5E+02
3E+02
5E+04
3E+02
1E+02
2E+02
2E+02
9E+04
4E+04
1E+04
5E+04
same as adult
Solubility
(mg/L)
2.6E+03
7.9E+03
2.2E+04
O.OE+00
O.OE+00
2.2E+04
6.1E+01
3.6E+04
1 .2E+03
1 .6E+02
7.4E+01
2.8E+02
8.5E+03
2.3E+03
2.8E+03
2.7E+03
2.7E+03
2.5E-02
2.7E+02
1 .OE+06
6.8E+01
6.6E+04
4.3E+04
(continued)
o'
s
vo
-------
to
o
Table 4-4. (continued)
CAS Name
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21-8 Ethylene oxide
50-00-0 Formaldehyde
98-01-1 Furfural
87-68-3 Hexachloro-1 ,3-butadiene
118-74-1 Hexachlorobenzene
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
Group
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Semi
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
25m
1E+04
6E+04
7E+02 a
4E-01
no risk
1E+00
7E+02 °
3E+03
3E+00
9E-01
1E-01
3E+01
4E+02
Adult Resident*
150m
7E+04
4E+05
5E+03
2E+00
no risk
8E+00
4E+03 °
1E+04
2E+01
5E+00
7E-01
2E+02
2E+03
1000m
no risk
b
no risk
1E+05
5E+01
no risk
2E+02
9E+04 °
3E+05
4E+02
1E+02
2E+01
4E+03
4E+04
NM
NM
2E-01 a
3E+05
1E+03
5E+03
3E+00
2E+01
4E+03
2E+00
no risk
9E+03
3E+04
2E+01
1E+02
3E+04
4E+01
no risk
2E+05
7E+05
5E+02
3E+03
6E+05
Child Resident 0-3 yr
25m 150m 1000m
same as adult
same as adult
same as adult
5E-01 3E+00 6E+01
same as adult
1 E+00 9E+00 2E+02
8E+02 ° 5E+03 ° 1 E+05 °
same as adult
3E+00 2E+01 5E+02
1 E+00 6E+00 1 E+02
same as adult
4E+01 2E+02 5E+03
same as adult
NM
NM
same as adult
same as adult
same as adult
same as adult
same as adult
2E+01 1 E+02 3E+03
same as adult
Solubility
(mg/L)
1 .OE+06
1 .OE+06
1 .7E+02
4.2E+03
1 .OE+06
3.8E+05
5.5E+05
1.1 E+05
3.2E+00
6.2E+00
1 .8E+00
5.0E+01
1 .2E+04
O.OE+00
O.OE+00
5.6E-02
1 .OE+06
1 .OE+06
1 .OE+06
1 .5E+04
5.3E+03
2.2E+05
(continued)
o'
s
-------
Table 4-4. (continued)
CAS Name
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
1 1 0-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
924-16-3 Nitrosodi-n-butylamine
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
110-86-1 Pyridine
100-42-5 Styrene
1 746-01 -6 TCDD, 2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
Group
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Vol
25m
2E+02
1E+03
4E+03
2E+02
8E+01
2E+04
1 E+02 a
4E+02
6E+00
Adult Resident*
150m
1E+03
7E+03
2E+04
1E+03
5E+02
1E+05
1 E+03 a
3E+03
3E+01
1000m
3E+04
1E+05
5E+05
2E+04
1E+04
b
no risk
2E+04 a
5E+04
7E+02 "
NM
2E+01
6E-02
5E-02
3E-02
2E+03
no risk
4E+01
1E+02
9E+02 a
1E-03b
6E+00
2E+00
5E+01
3E+02
1E+02
4E-01
3E-01
2E-01
1E+04
no risk
3E+02
7E+02
6E+03
5E-03
4E+01
1E+01
4E+02 a
2E+03 a
3E+03
7E+00
6E+00
4E+00
3E+05
no risk
6E+03
2E+04
1E+05
1E-01 "
9E+02
2E+02
8E+03
4E+04
Child
25m
Resident 0-3 yr
150m 1000m
same as adult
same as adult
same as adult
2E+02
9E+01
1 E+03 3E+04
6E+02 1 E+04 a
same as adult
same as adult
4E+02
3E+03 6E+04
same as adult
NM
same as adult
6E-02
5E-02
3E-02
4E-01 8E+00
3E-01 7E+00
2E-01 4E+00
same as adult
same as adult
5E+01
3E+02 6E+03
same as adult
same as adult
1E-03b
7E+00
2E+00
6E+01
6E-03 1 E-01
5E+01 1 E+03
1 E+01 2E+02
4E+02 9E+03
same as adult
Solubility
(mg/L)
1 .9E+04
1 .5E+04
3.9E+04
3.2E-03
1 .3E+04
1 .OE+06
1.2E+01
1 .OE+06
3.1 E+01
O.OE+00
2.1 E+03
1 .7E+04
1 .3E+03
9.3E+04
8.3E+04
6.2E+03
4.8E+05
1 .OE+06
3.1 E+02
1 .9E-05
1.1 E+03
3.0E+03
2.0E+02
5.3E+02
(continued)
o'
s
-------
to
to
Table 4-4. (continued)
CAS Name
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01-6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1330-20-7 Xylenes (total)
Group
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
25m
5E+01
2E+04 '
3E+02
6E+02
4E+00
2E+01
4E+02
2E+01
Adult Resident*
150m
3E+02
1E+05
2E+03
4E+03 a
2E+01
1E+02
3E+03 '
1E+02
1000m
7E+03
b
no risk
4E+04
9E+04
5E+02
3E+03 '
6E+04 '
2E+03
NM
3E+02
3E-01
3E+02 a
2E+03
2E+00
2E+03
4E+04
5E+01
4E+04
Child Resident 0-3 yr
25m 150m 1000m
6E+01 4E+02 8E+03
same as adult
same as adult
same as adult
5E+00 3E+01 6E+02
2E+01 2E+02 3E+03 '
same as adult
same as adult
NM
same as adult
4E-01 3E+00 6E+01
same as adult
Solubility
(mg/L)
1 .7E+04
1 .7E+02
3.0E+02
1 .3E+03
4.4E+03
1.1E+03
1.1E+03
5.5E+04
O.OE+00
2.0E+04
2.8E+03
1 .9E+02
NM = Not modeled for tanks.
no risk = the aqueous phase result exceeded 1 million parts per million (1,000,000 mg/kg or mg/L).
* For lead only, this column contains results for Child Resident 3-7 yrs.
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk is less than 1 E-5 or HQ = 1.
See Section 3.2A.3 for more details.
0 Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cwwill be lower if this constituent is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2.4.3 for more details.
o'
s
-------
Table 4-5. Chronic 90/90 Cw at 25 m to 1000 m, Risk = 10 5/HQ = 1 for Nonaerated Treatment Tanks (mg/L)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
107-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Aery lie acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71-43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1 ,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Adult Resident*
25m
8E+01
1E+05
3E+02
6E-02
6E+03
7E+02
2E+00
1E+00
8E+01
150m
4E+02
8E+05
1E+03
3E-01
3E+04
3E+03
1E+01
5E+00
4E+02
1000m
7E+03
no risk
3E+04
6E+00
5E+05
6E+04
2E+02
1E+02
8E+03
NM
NM
7E+00
7E+03
2E+02
4E+01
3E+04
8E+02
7E+02
6E+05
1E+04
NM
5E+00
1E+02
7E-02
2E+01
7E+02
4E-01
5E+02
1E+04
9E+00
NM
6E+02
3E+00
7E+00
3E+01
5E+00
3E+00
4E+00
3E+03
2E+01
4E+01
1E+02
3E+01
1E+01
2E+01
7E+04
4E+02
7E+02
3E+03
5E+02
3E+02
4E+02
25m
8E+01
Child Resident 0-3
150m
5E+02
yr
1000m
8E+03
same as adult
same as adult
same as adult
7E+03
3E+04
6E+05
same as adult
3E+00
1E+01
3E+02
same as adult
same as adult
NM
NM
8E+00
8E+03
2E+02
4E+01
b b
4E+04
b b
9E+02
8E+02
7E+05
2E+04
NM
6E+00
2E+02
9E-02
3E+01
8E+02
5E-01
5E+02
2E+04
1E+01
NM
same as adult
4E+00
2E+01
4E+02
same as adult
same as adult
6E+00
3E+00
3E+01
2E+01
6E+02
3E+02
same as adult
Solubility
(mg/L)
1 .OE+06
1 .OE+06
1 .OE+06
2.1E+05
6.4E+05
1 .OE+06
7.4E+04
3.4E+03
3.6E+04
O.OE+00
O.OE+00
1 .8E+03
5.0E+02
2.5E-02
O.OE+00
6.7E+03
3.1E+03
7.4E+02
O.OE+00
1 .2E+03
7.9E+02
1 .7E+03
4.7E+02
2.6E+03
7.9E+03
2.2E+04
(continued)
o'
s
to
-------
Table 4-5. (continued)
to
CAS Name
7440-47-3 Chromium VI
7440-48-4 Cobalt
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1 ,2-
106-46-7 Dichlorobenzene, 1 ,4-
75-71-8 Dichlorodifluoromethane
107-06-2 Dichloroethane, 1 ,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1,2-
10061-01-S Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
106-88-7 Epoxybutane, 1 ,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21-8 Ethylene oxide
50-00-0 Formaldehyde
98-01-1 Furfural
87-68-3 Hexachloro-1 ,3-butadiene
Group
Metal
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Adult Resident*
25m
150m
1000m
NM
NM
4E+01
4E+02
6E-01
4E+02
4E+02
2E+03
2E+02
3E+00
9E-01
5E+00
2E+00
2E+00
7E+02
2E+02
1E+04
8E+01
3E+02
4E+01
9E+03
6E+04
1E+03
5E-01
no risk
1E+00
5E+02
2E+03
7E+00
2E+02
2E+03
3E+00
2E+03
2E+03
8E+03
1E+03
2E+01
5E+00
3E+01
1E+01
1E+01
3E+03
1E+03
5E+04
4E+02
2E+03
2E+02
5E+04
3E+05
7E+03
3E+00
no risk
7E+00
3E+03
1E+04
4E+01
3E+03
5E+04
5E+01
4E+04
4E+04
1E+05
2E+04
3E+02
1E+02
5E+02
2E+02
2E+02
6E+04
2E+04
no risk
7E+03
3E+04
4E+03
9E+05
no risk
1E+05
5E+01
no risk
1E+02
5E+04
2E+05
8E+02
Child Resident 0-3 yr
25m
1 50 m 1 000 m
NM
NM
same as adult
same as adult
same as adult
5E+02
3E+03
5E+04
same as adult
same as adult
same as adult
4E+00
1E+00
2E+01
6E+00
4E+02
1E+02
same as adult
2E+00
3E+00
8E+02
2E+02
1E+01
1E+01
b b
4E+03
1E+03
2E+02
2E+02
7E+04
2E+04
same as adult
9E+01
3E+02
b b
4E+02
2E+03
8E+03
3E+04
same as adult
same as adult
same as adult
same as adult
6E-01
3E+00
6E+01
same as adult
2E+00
6E+02
9E+00
3E+03
2E+02
7E+04
same as adult
9E+00
4E+01
8E+02
Solubility
(mg/L)
O.OE+00
O.OE+00
2.2E+04
6.1E+01
3.6E+04
1 .2E+03
1 .6E+02
7.4E+01
2.8E+02
8.5E+03
2.3E+03
2.8E+03
2.7E+03
2.7E+03
2.5E-02
2.7E+02
1 .OE+06
6.8E+01
6.6E+04
4.3E+04
1 .OE+06
1 .OE+06
1 .7E+02
4.2E+03
1 .OE+06
3.8E+05
5.5E+05
1.1E+05
3.2E+00
(continued)
o'
s
-------
Table 4-5. (continued)
CAS Name
118-74-1 Hexachlorobenzene
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
110-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
924-16-3 Nitrosodi-n-butylamine
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
Group
Semi
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Vol
Vol
Semi
Adult Resident*
25 m 1 50 m 1 000 m
3E+00 2E+01 3E+02
3E-01 2E+00 3E+01
7E+01 3E+02 6E+03
3E+02 1 E+03 3E+04
NM
NM
5E-01 3E+00 5E+01
b b
2E+05 no risk no risk
1 E+03 6E+03 1 E+05
5E+03 2E+04 4E+05
5E+00 3E+01 5E+02
3E+01 2E+02 3E+03
5E+03 2E+04 5E+05
3E+02 2E+03 3E+04
2E+03 1 E+04 2E+05
7E+03 3E+04 6E+05
2E+02 9E+02 2E+04
1 E+02 7E+02 1 E+04
2E+04 8E+04 no risk
3E+02 1 E+03 3E+04
4E+02 2E+03 4E+04
1 E+01 5E+01 1 E+03
NM
2E+01 1 E+02 2E+03
7E-02 4E-01 7E+00
8E-02 4E-01 7E+00
2E-02 1 E-01 2E+00
2E+03 1 E+04 2E+05
Child Resident 0-3 yr
25 m 1 50 m 1 000 m
4E+00 2E+01 3E+02
same as adult
7E+01 4E+02 7E+03
same as adult
NM
NM
same as adult
same as adult
same as adult
same as adult
same as adult
4E+01 2E+02 4E+03
same as adult
same as adult
same as adult
same as adult
3E+02 1 E+03 2E+04
2E+02 8E+02 1 E+04
same as adult
same as adult
5E+02 2E+03 4E+04
same as adult
NM
same as adult
8E-02 4E-01 8E+00
1 E-01 4E-01 8E+00
3E-02 1 E-01 3E+00
same as adult
Solubility
(mg/L)
6.2E+00
1 .8E+00
5.0E+01
1 .2E+04
O.OE+00
O.OE+00
5.6E-02
1 .OE+06
1 .OE+06
1 .OE+06
1 .5E+04
5.3E+03
2.2E+05
1 .9E+04
1 .5E+04
3.9E+04
3.2E-03
1 .3E+04
1 .OE+06
1.2E+01
1 .OE+06
3.1 E+01
O.OE+00
2.1 E+03
1 .7E+04
1 .3E+03
9.3E+04
8.3E+04
(continued)
o'
s
to
-------
Table 4-5. (continued)
to
CAS Name
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
110-86-1 Pyridine
100-42-5 Styrene
1746-01-6 TCDD, 2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01-6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1330-20-7 Xylenes (total)
Group
Semi
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Adult Resident*
25m
no risk
5E+01
1E+02
2E+03
1E-03
1E+01
3E+00
1E+02
5E+02
5E+01
3E+04
7E+02
1E+03
6E+00
3E+01
6E+02
3E+01
150m
no risk
3E+02
5E+02
8E+03
6E-03
6E+01
1E+01
5E+02
2E+03
2E+02
2E+05
3E+03
5E+03
3E+01
2E+02
3E+03
1E+02
1000m
no risk
5E+03
1E+04
1E+05
1E-01 "
1E+03
3E+02
1E+04
5E+04
4E+03
no risk
6E+04
1E+05
6E+02
4E+03
7E+04
2E+03
NM
5E+02
5E-01
5E+02
2E+03
3E+00
3E+03
4E+04
5E+01
5E+04
Child Resident 0-3 yr
25 m 1 50 m 1 000 m
same as adult
6E+01 3E+02 6E+03
same as adult
same as adult
1 E-03 7E-03 1 E-01
1 E+01 7E+01 1 E+03
3E+00 2E+01 3E+02
1 E+02 6E+02 1 E+04
same as adult
5E+01 2E+02 5E+03
same as adult
same as adult
same as adult
7E+00 4E+01 7E+02
4E+01 2E+02 4E+03
same as adult
same as adult
NM
same as adult
6E-01 3E+00 6E+01
same as adult
Solubility
(mg/L)
6.2E+03
4.8E+05
1 .OE+06
3.1 E+02
1 .9E-05
1.1 E+03
3.0E+03
2.0E+02
5.3E+02
1 .7E+04
1 .7E+02
3.0E+02
1 .3E+03
4.4E+03
1.1 E+03
1.1 E+03
5.5E+04
O.OE+00
2.0E+04
2.8E+03
1 .9E+02
NM = Not modeled for tanks.
no risk = the aqueous phase result exceeded '\ million parts per million (1,000,000 mg/kg or mg/L).
* For lead only, this column contains results for Child Resident 3-7 yrs.
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
b Aqueous-phase result exceeds solubility or Csatat a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk is less than 1 E-5 or HQ = 1.
See Section 3.2A.3 for more details.
0 Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2.4.3 for more details.
o'
s
-------
Table 4-6. Chronic 90/90 Cw at 25 m, Risk + 10 5/HQ = 1 for Storage Tanks (mg/L)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
107-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Aery lie acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71-43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1 ,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Adult Resident*
25m
7E+02
no risk
2E+03
6E-01
2E+04
3E+03
2E+01
3E+01
5E+02
150m
5E+03
no risk
2E+04
4E+00
2E+05
3E+04
2E+02
2E+02
3E+03
1000m
1E+05
no risk
4E+05
9E+01
no risk
5E+05
3E+03
4E+03
8E+04
NM
NM
2E+02
3E+04
9E+02
1E+03
2E+05
6E+03
3E+04
no risk
1E+05
NM
8E+01
1E+03
3E+00
6E+02
1E+04
2E+01
1E+04
2E+05
4E+02
NM
2E+04
1E+02
2E+02
6E+02
6E+01
6E+01
4E+01
1E+05
7E+02
1E+03
5E+03
4E+02
4E+02
3E+02
no risk
2E+04
3E+04
1E+05
1E+04
1E+04
7E+03
25m
8E+02
Child Resident 0-3
150m
5E+03
yr
1000m
1E+05
same as adult
same as adult
same as adult
3E+04
2E+05
no risk
same as adult
2E+01
2E+02
4E+03
same as adult
same as adult
NM
NM
2E+02
3E+04
1E+03
1E+03
3E+05
6E+03
3E+04
no risk
1E+05
NM
9E+01
2E+03
3E+00
7E+02
1E+04
2E+01
1E+04
3E+05
5E+02
NM
same as adult
1E+02
9E+02
2E+04
same as adult
same as adult
7E+01
7E+01
5E+02
5E+02
1E+04
1E+04
same as adult
Solubility
(mg/L)
1 .OE+06
1 .OE+06
1 .OE+06
2.1E+05
6.4E+05
1 .OE+06
7.4E+04
3.4E+03
3.6E+04
O.OE+00
O.OE+00
1 .8E+03
5.0E+02
2.5E-02
O.OE+00
6.7E+03
3.1E+03
7.4E+02
O.OE+00
1 .2E+03
7.9E+02
1 .7E+03
4.7E+02
2.6E+03
7.9E+03
2.2E+04
(continued)
o'
s
to
-------
to
Table 4-6. (continued)
CAS Name
7440-47-3 Chromium VI
7440-48-4 Cobalt
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1 ,2-
106-46-7 Dichlorobenzene, 1,4-
75-71-8 Dichlorodifluoromethane
107-06-2 Dichloroethane, 1,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1,2-
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
106-88-7 Epoxybutane, 1,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21-8 Ethylene oxide
50-00-0 Formaldehyde
98-01-1 Furfural
87-68-3 Hexachloro-1 ,3-butadiene
Group
Metal
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Adult Resident*
25m
150m
1000m
NM
NM
2E+02
2E+04
4E+00
3E+03
7E+03
3E+04
7E+03
5E+01
3E+01
1E+02
4E+01
4E+01
3E+03
9E+02
7E+04
4E+02
2E+03
6E+02
5E+04
3E+05
3E+04
6E+00
no risk
1E+01
3E+03
1E+04
2E+02
1E+03
1E+05
3E+01
2E+04
5E+04
2E+05
5E+04
4E+02
2E+02
9E+02
3E+02
3E+02
2E+04
7E+03
6E+05
3E+03
1E+04
4E+03
4E+05
no risk
3E+05
5E+01
no risk
1E+02
2E+04
9E+04
1E+03
3E+04
no risk
6E+02
6E+05
no risk
no risk
no risk
9E+03
4E+03
2E+04
6E+03
6E+03
5E+05
2E+05
no risk
7E+04
3E+05
9E+04
no risk
no risk
no risk
1E+03
no risk
2E+03
5E+05
no risk
3E+04
25m
Child Resident 0-3
150m
yr
1000m
NM
NM
same as adult
same as adult
same as adult
4E+03
3E+04
6E+05
same as adult
same as adult
same as adult
6E+01
3E+01
5E+02
2E+02
1E+04
5E+03
same as adult
4E+01
4E+01
3E+03
1E+03
3E+02
3E+02
2E+04
8E+03
7E+03
7E+03
5E+05
2E+05
same as adult
4E+02
2E+03
3E+03
2E+04
8E+04
4E+05
same as adult
same as adult
same as adult
same as adult
7E+00
5E+01
1E+03
same as adult
2E+01
3E+03
1E+02
2E+04
3E+03
5E+05
same as adult
2E+02
2E+03
4E+04
Solubility
(mg/L)
O.OE+00
O.OE+00
2.2E+04
6.1E+01
3.6E+04
1 .2E+03
1 .6E+02
7.4E+01
2.8E+02
8.5E+03
2.3E+03
2.8E+03
2.7E+03
2.7E+03
2.5E-02
2.7E+02
1 .OE+06
6.8E+01
6.6E+04
4.3E+04
1 .OE+06
1 .OE+06
1 .7E+02
4.2E+03
1 .OE+06
3.8E+05
5.5E+05
1.1E+05
3.2E+00
o'
s
(continued)
-------
Table 4-6. (continued)
CAS Name
118-74-1 Hexachlorobenzene
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
110-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
924-16-3 Nitrosodi-n-butylamine
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
Group
Semi
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Vol
Vol
Semi
Adult Resident*
25m
3E+01
9E+00
6E+02
2E+03
150m
2E+02
7E+01
5E+03
1E+04
1000m
4E+03
2E+03
1E+05
3E+05
NM
NM
1E+01
no risk
7E+03
2E+04
1E+02
9E+02
4E+04
3E+03
2E+04
9E+04
9E+02
3E+03
8E+04
9E+03
2E+03
1E+02
1E+02
no risk
5E+04
2E+05
9E+02
7E+03
3E+05
2E+04
2E+05
6E+05
6E+03
2E+04
6E+05
6E+04
1E+04
8E+02
2E+03
no risk
no risk
no risk
2E+04
2E+05
no risk
5E+05
no risk
no risk
1E+05
4E+05
no risk
no risk
3E+05
2E+04
NM
1E+02
6E-01
1E+00
1E-01
1E+04
1E+03
4E+00
7E+00
1E+00
9E+04
2E+04
1E+02
2E+02
2E+01
no risk
Child Resident 0-3 yr
25m 150m 1000m
3E+01 2E+02 5E+03
same as adult
7E+02 5E+03 1 E+05
same as adult
NM
NM
same as adult
same as adult
same as adult
same as adult
same as adult
1 E+03 8E+03 2E+05
same as adult
same as adult
same as adult
same as adult
1 E+03 7E+03 2E+05
3E+03 2E+04 5E+05
same as adult
same as adult
2E+03 1 E+04 3E+05
same as adult
NM
same as adult
7E-01 5E+00 1 E+02
1 E+00 8E+00 2E+02
1 E-01 1 E+00 3E+01
same as adult
Solubility
(mg/L)
6.2E+00
1 .8E+00
5.0E+01
1 .2E+04
O.OE+00
O.OE+00
5.6E-02
1 .OE+06
1 .OE+06
1 .OE+06
1 .5E+04
5.3E+03
2.2E+05
1 .9E+04
1 .5E+04
3.9E+04
3.2E-03
1 .3E+04
1 .OE+06
1 .2E+01
1 .OE+06
3.1E+01
O.OE+00
2.1 E+03
1 .7E+04
1 .3E+03
9.3E+04
8.3E+04
(continued)
o'
s
to
VO
-------
-^
o
Table 4-6. (continued)
CAS Name
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
110-86-1 Pyridine
100-42-5 Styrene
1746-01-6 TCDD, 2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01-6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1330-20-7 Xylenes (total)
Group
Semi
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Adult Resident*
25m
no risk
5E+02
7E+02
3E+04
6E-03
2E+02
3E+01
3E+03
1E+04
2E+02
no risk
9E+03
3E+04
9E+01
9E+02
2E+04
2E+02
150m
no risk
3E+03
5E+03
2E+05
4E-02
2E+03
2E+02
2E+04
9E+04
2E+03
no risk
6E+04
2E+05
7E+02
6E+03
1E+05
2E+03
1000m
no risk
7E+04
1E+05
no risk
9E-01 "
4E+04
5E+03
4E+05
no risk
4E+04
no risk
no risk
no risk
2E+04
1E+05
no risk
4E+04
NM
6E+03
1E+01
1E+04
4E+04
1E+02
9E+04
9E+05
2E+03
no risk
Child Resident 0-3 yr
25m 150m 1000m
same as adult
5E+02 4E+03 8E+04
same as adult
same as adult
7E-03 4E-02 1 E+00
2E+02 2E+03 4E+04
3E+01 2E+02 6E+03
3E+03 2E+04 5E+05
same as adult
3E+02 2E+03 5E+04
same as adult
same as adult
same as adult
1 E+02 8E+02 2E+04
1 E+03 7E+03 2E+05
same as adult
same as adult
NM
same as adult
2E+01 1 E+02 3E+03
same as adult
Solubility
(mg/L)
6.2E+03
4.8E+05
1 .OE+06
3.1 E+02
1 .9E-05
1.1 E+03
3.0E+03
2.0E+02
5.3E+02
1 .7E+04
1 .7E+02
3.0E+02
1 .3E+03
4.4E+03
1.1 E+03
1.1 E+03
5.5E+04
O.OE+00
2.0E+04
2.8E+03
1 .9E+02
NM = Not modeled for tanks.
no risk = the aqueous phase result exceeded ~\ million parts per million (1,000,000 mg/kg or mg/L).
* For lead only, this column contains results for Child Resident 3-7 yrs.
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk is less than 1 E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
0 Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2A.3 for more details.
o'
s
-------
Volume 1
Section 4.0
Table 4-7. Physical-Chemical Properties and Health Benchmarks
CAS
75-07-0
67-64-1
75-05-8
107-02-8
79-06-1
79-10-7
107-13-1
107-05-1
62-53-3
7440-38-2
7440-39-3
71-43-2
92-87-5
50-32-8
7440-41-7
75-27-4
75-25-2
106-99-0
7440-43-9
75-15-0
56-23-5
126-99-8
108-90-7
124-48-1
67-66-3
95-57-8
7440-47-3
7440-48-4
1319-77-3
98-82-8
108-93-0
96-12-8
95-50-1
106-46-7
75-71-8
107-06-2
75-35-4
78-87-5
10061-01-5
10061-02-6
57-97-6
121-14-2
123-91-1
122-66-7
Name
Acetaldehyde
Acetone
Acetonitrile
Acrolein
Acrylamide
Acrylic acid
Acrylonitrile
Allyl chloride
Aniline
Arsenic
Barium
Benzene
Benzidine
Benzo(a)pyrene
Beryllium
Bromodichloromethane
Bromoform (Tribromomethane)
Butadiene, 1 ,3-
Cadmium
Carbon disulfide
Carbon tetrachloride
Chloro-1 ,3-butadiene, 2- (Chloroprene)
Chlorobenzene
Chlorodibromomethane
Chloroform
Chlorophenol, 2-
Chromium VI
Cobalt
Cresols (total)
Cumene
Cyclohexanol
Dibromo-3-chloropropane, 1 ,2-
Dichlorobenzene, 1 ,2-
Dichlorobenzene, 1 ,4-
Dichlorodifluoromethane
Dichloroethane, 1 ,2-
Dichloroethylene, 1,1-
Dichloropropane, 1,2-
Dichloropropene, cis-1 ,3-
Dichloropropene, trans-1 ,3-
Dimethylbenz(a)anthracene, 7,12-
Dinitrotoluene, 2,4-
Dioxane, 1,4-
Diphenylhydrazine, 1,2-
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Metal
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Inhal CSF
(mg/kg-d)-1
8E-03
NA
NA
NA
5E+00
NA
2E-01
NA
NA
2E+01
NA
3E-02
2E+02
3E+00
8E+00
6E-02
4E-03
2E+00
6E+00
NA
5E-02
NA
NA
8E-02
8E-02
NA
4E+01
NA
NA
NA
NA
2E-03
NA
NA
NA
9E-02
2E-01
NA
1E-01
1E-01
8E+01
7E-01
NA
8E-01
RfC
(mg/m3)
9E-03
3E+01
6E-02
2E-05
NA
1E-03
2E-03
1E-03
1E-03
NA
5E-04
NA
NA
NA
2E-05
NA
NA
NA
NA
7E-01
NA
7E-03
2E-02
NA
NA
1E-03
1E-04
1E-05
4E-04
4E-01
2E-05
2E-04
2E-01
8E-01
2E-01
NA
NA
4E-03
2E-02
2E-02
NA
NA
8E-01
NA
HLC
(atm-m3/mol)
8E-05
4E-05
3E-05
1E-04
1E-09
1E-07
1E-04
1E-02
2E-06
0
0
6E-03
4E-11
1E-06
0
2E-03
5E-04
7E-02
0
3E-02
3E-02
1E-02
4E-03
8E-04
4E-03
4E-04
0
0
2E-06
1E+00
4E-06
1E-04
2E-03
2E-03
3E-01
1E-03
3E-02
3E-03
2E-03
1E-03
3E-08
9E-08
5E-06
2E-06
Solubility
(mg/L)
1E+06
1E+06
1E+06
2E+05
6E+05
1E+06
7E+04
3E+03
4E+04
0
0
2E+03
5E+02
3E-02
0
7E+03
3E+03
7E+02
0
1E+03
8E+02
2E+03
5E+02
3E+03
8E+03
2E+04
0
0
2E+04
6E+01
4E+04
1E+03
2E+02
7E+01
3E+02
9E+03
2E+03
3E+03
3E+03
3E+03
3E-02
3E+02
1E+06
7E+01
Csat
(mg/kg)
3E+05
2E+05
2E+05
5E+04
1E+05
2E+05
2E+04
2E+03
1E+04
1E+06
1E+06
2E+03
2E+02
2E+02
1E+06
6E+03
5E+03
1E+03
1E+06
1E+03
3E+03
2E+03
2E+03
3E+03
6E+03
2E+04
1E+06
1E+06
5E+03
2E+03
2E+04
2E+03
2E+03
1E+03
1E+03
3E+03
3E+03
2E+03
2E+03
2E+03
5E+02
2E+02
2E+05
3E+02
(continued)
4-31
-------
Volume 1
Section 4.0
Table 4-7. (continued)
CAS
106-89-8
106-88-7
111-15-9
110-80-5
100-41-4
106-93-4
107-21-1
75-21-8
50-00-0
98-01-1
87-68-3
118-74-1
77-47-4
67-72-1
78-59-1
7439-92-1
7439-96-5
7439-97-6
67-56-1
110-49-6
109-86-4
74-83-9
74-87-3
78-93-3
108-10-1
80-62-6
1634-04-4
56-49-5
75-09-2
68-12-2
91-20-3
110-54-3
7440-02-0
98-95-3
79-46-9
55-18-5
924-16-3
930-55-2
108-95-2
85-44-9
75-56-9
110-86-1
100-42-5
1746-01-6
Name
Epichlorohydrin
Epoxybutane, 1 ,2-
Ethoxyethanol acetate (R-R), 2-
Ethoxyethanol, 2-
Ethylbenzene
Ethylene Dibromide
Ethylene glycol
Ethylene oxide
Formaldehyde
Furfural
Hexachloro-1 ,3-butadiene
Hexachlorobenzene
Hexachlorocyclopentadiene
Hexachloroethane
Isophorone
Lead
Manganese
Mercury
Methanol
Methoxyethanol acetate (R-R), 2-
Methoxyethanol, 2-
Methyl bromide (Bromomethane)
Methyl chloride (Chloromethane)
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
Methyl tert-butyl ether
Methylcholanthrene, 3-
Methylene chloride
N,N-Dimethylformamide
Naphthalene
n-Hexane
Nickel
Nitrobenzene
Nitropropane, 2-
Nitrosodiethylamine
Nitrosodi-n-butylamine
N-Nitrosopyrrolidine
Phenol
Phthalic anhydride
Propylene oxide
Pyridine
Styrene
TCDD, 2,3,7,8-
Group
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Semi
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Metal
Semi
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Vol
Semi
Inhal CSF
(mg/kg-d)-1
4E-03
NA
NA
NA
NA
8E-01
NA
4E-01
5E-02
NA
8E-02
2E+00
NA
1E-02
NA
NA
NA
NA
NA
NA
NA
NA
6E-03
NA
NA
NA
NA
7E+00
2E-03
NA
NA
NA
8E-01
NA
9E+00
2E+02
6E+00
2E+00
NA
NA
1E-02
NA
NA
2E+05
RfC HLC
(mg/m3) (atm-m3/mol)
1E-03
2E-02
3E-01
2E-01
1E+00
2E-04
6E-01
NA
NA
5E-02
NA
NA
7E-05
NA
1E-02
NA
5E-05
3E-04
1E+01
3E-02
2E-02
5E-03
NA
1E+00
8E-02
7E-01
3E+00
NA
3E+00
3E-02
3E-03
2E-01
NA
2E-03
2E-02
NA
NA
NA
6E-03
1E-01
3E-02
7E-03
1E+00
NA
3E-05
5E-04
2E-06
4E-07
8E-03
7E-04
6E-08
1E-04
3E-07
4E-06
8E-03
1E-03
3E-02
4E-03
7E-06
0
0
9E-03
5E-06
2E-06
3E-07
6E-03
9E-03
6E-05
1E-04
3E-04
6E-04
9E-07
2E-03
2E-07
5E-04
1E-02
0
2E-05
1E-04
4E-06
3E-04
1E-08
4E-07
2E-08
9E-05
9E-06
3E-03
2E-05
Solubility Csat
(mg/L) (mg/kg)
7E+04
4E+04
1E+06
1E+06
2E+02
4E+03
1E+06
4E+05
6E+05
1E+05
3E+00
6E+00
2E+00
5E+01
1E+04
0
0
6E-02
1E+06
1E+06
1E+06
2E+04
5E+03
2E+05
2E+04
2E+04
4E+04
3E-03
1E+04
1E+06
3E+01
1E+01
0
2E+03
2E+04
9E+04
1E+03
1E+06
8E+04
6E+03
5E+05
1E+06
3E+02
2E-05
2E+04
2E+04
2E+05
2E+05
1E+03
3E+03
2E+05
9E+04
1E+05
3E+04
1E+03
2E+04
2E+03
3E+03
6E+03
1E+06
1E+06
3E+01
2E+05
2E+05
2E+05
6E+03
2E+03
5E+04
6E+03
6E+03
3E+04
4E+01
5E+03
2E+05
4E+02
6E+02
1E+06
1E+03
5E+03
2E+04
2E+03
2E+05
3E+04
1E+03
1E+05
3E+05
2E+03
4E-01
(continued)
4-32
-------
Volume 1
Section 4.0
Table 4-7. (continued)
CAS
630-20-6
79-34-5
127-18-4
108-88-3
95-53-4
76-13-1
120-82-1
71-55-6
79-00-5
79-01-6
75-69-4
121-44-8
7440-62-2
108-05-4
75-01-4
1330-20-7
Name
Tetrachloroethane, 1,1,1,2-
Tetrachloroethane, 1,1,2,2-
Tetrachloroethylene
Toluene
Toluidine, o-
Trichloro-1 ,2,2-trifluoroethane, 1,1,2-
Trichlorobenzene, 1,2,4-
Trichloroethane, 1,1,1-
Trichloroethane, 1,1,2-
Trichloroethylene
Trichlorofluoromethane
Triethylamine
Vanadium
Vinyl acetate
Vinyl chloride
Xylenes (total)
Group
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Inhal CSF
(mg/kg-d)-1
3E-02
2E-01
2E-03
NA
2E-01
NA
NA
NA
6E-02
6E-03
NA
NA
NA
NA
3E-01
NA
RfC HLC
(mg/m3) (atm-m3/mol)
NA
NA
3E-01
4E-01
NA
3E+01
2E-01
1E+00
NA
NA
7E-01
7E-03
7E-05
2E-01
NA
4E-01
2E-03
3E-04
2E-02
7E-03
3E-06
5E-01
1E-03
2E-02
9E-04
1E-02
1E-01
1E-04
0
5E-04
3E-02
6E-03
Solubility
(mg/L)
1E+03
3E+03
2E+02
5E+02
2E+04
2E+02
3E+02
1E+03
4E+03
1E+03
1E+03
6E+04
0
2E+04
3E+03
2E+02
Csat
(mg/kg)
3E+03
5E+03
6E+02
2E+03
6E+03
2E+03
2E+04
3E+03
4E+03
3E+03
3E+03
2E+04
1E+06
5E+03
2E+03
2E+03
Cw's that are greater than their solubility limit at a neutral pH and temperature of 20 to 25° C. As
discussed in Section 3.2.4.3, the actual solubility of a constituent in a waste stream is dependent
on site-specific conditions including pH , temperature, and the presence of other chemicals and
metals. Therefore, the solubility limit will differ from the limit at a neutral pH and temperature
of 20 to 25° C under different conditions. When a constituent exceeded its solubility limit at a
neutral pH and temperature of 20 to 25° C, we modeled the constituent as pure component. Both
2,3,7,8-TCDD and mercury, when modeled as pure component did not exceed the target risk
level of 10-5oranHQof 1.
Ranking of Cw by WMU Type
(low to high)
Aerated tank/Nonaerated tank
Storage tank/LAU
Landfill
Wastepile
4.3 Effect of WMU Type
The Cw' s from the different WMU types rank fairly
consistently across chemicals. Treatment tanks (both
aerated and nonaerated) typically result in the lowest Cw as a
result of the aeration, which aids volatilization, or the
generally large areas associated with nonaerated treatment
tanks. Storage tanks and land application units (LAUs) are
next, usually about two orders of magnitude higher; these
are typically within an order of magnitude of each other. Landfills are next. These usually differ
from LAUs by less than an order of magnitude. The wastepiles usually give the highest results,
about an order of magnitude higher than the landfills.
Table 4-8 shows the number of chemicals for which each WMU type was most limiting.
For most chemicals modeled in the tanks, aerated or nonaerated treatment tanks were the most
4-33
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Volume 1
Section 4.0
Table 4-8. Most Limiting WMU Type
Number of Chemicals
WMU Type
All tanks
Aerated Treatment
Nonaerated Treatment
Storage
LAU
Landfill
Wastepile
No risk
Total
Volatiles
69
52
17
0
1
0
0
1
71
Semivolatiles
21
6
15
0
Not modeled
Not modeled
Not modeled
2
23
Metals
Not modeled
Not modeled
Not modeled
Not modeled
10
0
0
0
10
Total
90
11
0
0
3
104
58
32
0
limiting unit. The only exception is N-Nitrosopyrrolidene in LAUs. Three chemicals had no risk
in any of the WMU types (see Section 4.2).
4.4 Effect of Exposure Factors
Rank of Receptors
(low to high)
Adult resident
Child resident 0-3 yrs
Child resident 4-10 yrs
Child resident 11-18 yrs
Offsite worker
The effect of exposure factors can be seen by comparing
results for different receptors. This is possible only for carcinogens,
as exposure factors are not explicitly accounted for in the
calculations for noncarcinogens. For all WMU types except
landfills, adult resident receptors give the lowest results. This is
because while child receptors have a higher inhalation rate relative
to body weight than the adult, they are exposed for a shorter
duration. The off-site worker is also exposed fewer days per year.
For landfills, exposure duration is capped at 20 years, the assumed
operating life of the unit. This affects adults more significantly than children, so that adults are
similar to children age 4-10 years in the ranking. The offsite worker gives higher results than the
residents by less than an order of magnitude. The worker has a higher hourly inhalation rate than
an adult resident but is exposed only 8 hours per day instead of 24.
4.5 Subchronic and Acute Results
This section presents the results for subchronic and acute exposures and compares them
to the results for chronic exposures. Not all chemicals were included in the assessments for the
subchronic and acute exposures due to limitations in available health benchmarks. Sixty-two
chemicals were included in the assessment of subchronic exposures, and 35 chemicals were
included in the assessment of acute exposures. All subchronic and acute results described in this
section are for a resident; because acute and subchronic health benchmarks are expressed as an
air concentration, exposure factors are not used, so there is no distinction between receptors.
Waste concentration levels (Cw's) are presented based on the most exposed individual at each
site. From the cumulative distribution of this concentration across all sites, the 90th percentile
4-34
-------
Volume 1 Section 4.0
was chosen; thus the results presented here protect 100 percent of the receptors at 90 percent of
the sites at an HQ of 1 (100/90 levels). The detailed results that are summarized here, as well as
results for additional distances, are presented in Volume III: Results.
Tables 4-9 and 4-10 show acute and subchronic results by distance for LAUs and
wastepiles, respectively. The range of the most protective (i.e., lowest) Cw values for both
WMUs was similar for subchronic, acute, and chronic. The results for subchronic and acute
exposures show patterns similar to those for chronic exposures with respect to chemical
properties, toxicity, and WMUs, except that toxicity was more important and there was less
difference between the results for LAUs and wastepiles.
Tables 4-11 and 4-12 compare the subchronic and acute Cw's to the chronic 90/90 values
for adults for all chemicals for LAUs and wastepiles, respectively. All values shown are for
75m.
Several factors are likely to affect the subchronic and acute results differently than the
chronic results:
1. Acute and subchronic health benchmarks were taken from several sources and so
do not reflect a consistent methodology across chemicals.
2. The hazard posed by a chemical is likely to vary with exposure duration, i.e.,
some chemicals will have greater hazard at chronic exposures, others at acute and
subchronic exposures.
3. Biodegradation is less likely to be an important factor for subchronic and acute
exposures.
For both WMUs, the acute results, subchronic results, and chronic results show no pattern
with respect to each other. Any of the three results may be lowest depending on the chemical,
and the difference ranges from negligible up to two orders of magnitude. No pattern is apparent
based on source of the toxicity benchmark or other physical-chemical properties affecting
volatility or biodegradation.
4-35
-------
Table 4-9. Acute and Subchronic 100/90 Cw at 25 to 75 m for HQ = 1 for Land Application Units (mg/kg)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
107-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Acrylic acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71-43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
7440-47-3 Chromium VI
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Metal
Subchronic
25m
5E+03
no risk
2E+03
5E+00
50 m
6E+03
no risk
3E+03
6E+00
75m
7E+03
no risk
3E+03
7E+00
NM
NM
5E+02
7E+01
7E+02
1E+02
8E+02
1E+02
NM
NMS
2E+05
1E+02
3E+05
2E+02
3E+05
2E+02
NM
NM
NMS
NMS
NMS
NMS
NMS
5E+03
2E+03
7E+03
3E+03
9E+03
4E+03
NMS
3E+03
4E+03
4E+03
NMS
2E+03
3E+03
3E+03
NM
2E+04
3E+04
3E+04
Acute
25 m 50 m 75 m
NMA
2E+05 ° 3E+05 a,c 3E+05 ''"
NMA
1 E-01 2E-01 2E-01
NM
NM
3E+02 4E+02 5E+02
NMA
NM
6E+03 7E+03 8E+03
NMA
1 E+02 2E+02 2E+02
NM
NM
NMA
NMA
NMA
NMA
NMA
1 E+04 1 E+04 2E+04
9E+02 1 E+03 1 E+03
NMA
NMA
NMA
4E+02 5E+02 6E+02
NM
NMA
(mg/kg)
3.3E+05
2.3E+05
2.3E+05
5.0E+04
1 .5E+05
2.4E+05
1 .8E+04
1 .7E+03
1 .OE+04
1 .OE+06
1 .OE+06
1 .8E+03
2.4E+02
1 .5E+02
1 .OE+06
6.3E+03
4.5E+03
1.1 E+03
1 .OE+06
1 .3E+03
2.7E+03
1 .8E+03
2.0E+03
2.7E+03
5.7E+03
2.2E+04
1 .OE+06
o'
s
(continued)
-------
Table 4-9. (continued)
CAS Name
7440-48-4 Cobalt
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1,2-
106-46-7 Dichlorobenzene, 1,4-
75-71-8 Dichlorodifluoromethane
1 07-06-2 Dichloroethane, 1 ,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1 ,2-
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
106-88-7 Epoxybutane, 1,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21 -8 Ethylene oxide
50-00-0 Formaldehyde
98-01-1 Furfural
87-68-3 Hexachloro-1,3-butadiene
118-74-1 Hexachlorobenzene
Group
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Semi
Subchronic
25m
1E+03
50 m
2E+03
75m
2E+03
NM
8E+04
2E+01
3E+02
2E+05
2E+05
1E+04
6E+03
6E+02
1E+02
4E+02
4E+02
1E+05
2E+01
4E+02
3E+05
3E+05
2E+04
1E+04
8E+02
1E+02
5E+02
5E+02
1E+05
2E+01
5E+02
3E+05
3E+05
2E+04
1E+04
1E+03
2E+02
6E+02
7E+02
NM
NM
3E+05 a'°
4E+05 a'°
5E+05 a'°
NM
6E+02
4E+03
7E+02
5E+03
8E+02
6E+03
NMS
8E+05 a'°
1E+04
4E+01
no risk
2E+04
6E+01
no risk
2E+04
7E+01
NM
5E+03
4E+03
1E+04
6E+03
5E+03
2E+04
7E+03
7E+03
2E+04
NM
NM
Acute
25 m 50 m 75 m
NMA
NM
NMA
NMA
NMA
NMA
2E+04 3E+04 3E+04
NMA
6E+02 9E+02 1 E+03
NMA
2E+02 2E+02 3E+02
NMA
NMA
NM
NM
1 E+04 1 E+04 1 E+04
NM
7E+03 1 E+04 1 E+04
NMA
2E+03 3E+03 4E+03
2E+04 3E+04 3E+04
NMA
NMA
NM
NMA
2E+03 2E+03 2E+03
NMA
NM
NM
csa,
(mg/kg)
1 .OE+06
5.2E+03
1 .9E+03
1 .6E+04
1 .8E+03
2.2E+03
1 .OE+03
1 .2E+03
3.4E+03
2.7E+03
2.2E+03
2.2E+03
2.2E+03
4.8E+02
2.1E+02
2.3E+05
3.3E+02
1 .6E+04
1 .7E+04
2.3E+05
2.3E+05
1 .3E+03
3.1 E+03
2.3E+05
8.9E+04
1 .3E+05
2.7E+04
1 .OE+03
2.3E+04
o'
s
(continued)
-------
-^
oo
Table 4-9. (continued)
CAS Name
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
110-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
924-16-3 Nitrosodi-n-butylamine
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
Group
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Vol
Vol
Semi
Semi
Vol
Subchronic
25m
50 m
75m
NM
no risk
no risk
no risk
NM
NMS
2E+04
9E+00
3E+04
1E+01
3E+04
1E+01
NMS
NMS
5E+04
1E+03
3E+03
6E+04
5E+04
2E+05
2E+04
7E+04
2E+03
4E+03
7E+04
6E+04
2E+05
4E+04
8E+04
2E+03
5E+03
9E+04
7E+04
3E+05
5E+04
NM
2E+04
3E+04
4E+04
NM
3E+03
4E+03
5E+03
NMS
8E+03
8E+04
1E+04
1E+05
1E+04
1E+05
NM
3E+02
4E+02
6E+02
NMS
NMS
NM
NM
1E+03
1E+03
2E+03
Acute
25 m 50 m 75 m
NM
5E+05 8E+05 9E+05
NM
NMA
NMA
5E+00 7E+00 8E+00
2E+05 a'° 3E+05 ^ 4E+05 °'°
NMA
5E+02 6E+02 7E+02
1 E+02 2E+02 2E+02
6E+02 7E+02 7E+02
1 E+05 1 E+05 2E+05
NMA
NMA
8E+03 9E+03 1 E+04
NM
6E+03 9E+03 1 E+04
NM
NMA
NMA
NMA
1 E+05 2E+05 2E+05
NM
NMA
NMA
NMA
NM
NM
1 E+04 2E+04 2E+04
csa,
(mg/kg)
2.1E+03
2.6E+03
6.1E+03
1 .OE+06
1 .OE+06
2.6E+01
2.3E+05
2.3E+05
2.3E+05
5.7E+03
1 .9E+03
5.4E+04
6.0E+03
5.5E+03
2.6E+04
4.0E+01
4.6E+03
2.3E+05
6.4E+02
2.3E+05
3.8E+02
1 .OE+06
1 .3E+03
4.6E+03
2.1E+03
2.3E+04
3.3E+04
1 .4E+03
1.1 E+05
o'
s
(continued)
-------
Table 4-9. (continued)
CAS Name
110-86-1 Pyridine
100-42-5 Styrene
1746-01-6 TCDD, 2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1 ,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01 -6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1330-20-7 Xylenes (total)
Group
Vol
Vol
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Subchronic
25m
50 m
75m
NMS
3E+05
3E+05
4E+05
NM
NMS
8E+04
2E+04
4E+04
1E+05
3E+04
6E+04
1E+05
4E+04
8E+04
NM
NMS
NM
3E+04
4E+04
5E+04
NMS
5E+03
5E+04
9E+02
3E+03
5E+03
6E+02
5E+04
6E+03
7E+04
1E+03
4E+03
6E+03
7E+02
7E+04
8E+03
9E+04
2E+03
4E+03
7E+03
1E+03
9E+04
Acute
25 m 50 m 75 m
NMA
1 E+05 2E+05 2E+05
NM
NMA
NMA
1 E+03 1 E+03 1 E+03
2E+04 2E+04 2E+04
NM
NMA
NM
7E+03 9E+03 1 E+04
NMA
1 E+04 1 E+04 1 E+04
NMA
NMA
1 E+04 1 E+04 1 E+04
NMA
7E+02 9E+02 1 E+03
6E+03 7E+03 8E+03
csa,
(mg/kg)
2.6E+05
1 .5E+03
3.8E-01
2.8E+03
4.7E+03
5.9E+02
1 .7E+03
5.9E+03
2.1 E+03
1 .6E+04
2.7E+03
3.8E+03
3.4E+03
3.3E+03
2.1 E+04
1 .OE+06
5.3E+03
1 .8E+03
1 .5E+03
NM = Not modeled for land-based units.
NMA = Not modeled for acute.
NMS = Not modeled for subchronic.
no risk = the aqueous phase result exceeded ~\ million parts per million (1,000,000 mg/kg or mg/L).
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2A.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk is less than 1 E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
0 Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2A.3 for more details.
-^
VO
o'
s
-------
-^
o
Table 4-10. Acute and Subchronic 100/90 Cw at 25 to 75 m for HQ = 1 for Wastepiles (mg/kg)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
1 07-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Acrylic acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71 -43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1 ,3-butadiene, 2- (Chloroprene)
1 08-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
7440-47-3 Chromium VI
7440-48-4 Cobalt
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Metal
Metal
25m
2E+03
6E+05 a'°
1E+03
3E+00
Subchronic
50m
3E+03
b,c
no risk
2E+03
5E+00
75m
5E+03
no risk
3E+03
7E+00
NM
NM
3E+02
3E+01
5E+02
4E+01
7E+02
6E+01
NM
NMS
7E+04
8E+01
1E+05
1E+02
2E+05
2E+02
NM
NM
NMS
NMS
NMS
NMS
NMS
2E+03
2E+03
3E+03
3E+03
4E+03
4E+03
NMS
3E+03
5E+03
8E+03
NMS
1E+03
2E+03
4E+03
NM
7E+03
4E+02
1E+04
7E+02
2E+04
1E+03
Acute
25 m 50 m 75m
NMA
8E+04 1 E+05 2E+05
NMA
9E-02 1 E-01 2E-01
NM
NM
2E+02 3E+02 4E+02
NMA
NM
2E+03 3E+03 3E+03
NMA
6E+01 1 E+02 1 E+02
NM
NM
NMA
NMA
NMA
NMA
NMA
3E+03 5E+03 7E+03
4E+02 6E+02 9E+02
NMA
NMA
NMA
2E+02 3E+02 4E+02
NM
NMA
NMA
75 m Csat
(mg/kg)
3.3E+05
2.3E+05
2.3E+05
5.0E+04
1 .5E+05
2.4E+05
1 .8E+04
1 .7E+03
1 .OE+04
1 .OE+06
1 .OE+06
1 .8E+03
2.4E+02
1 .5E+02
1 .OE+06
6.3E+03
4.5E+03
1.1E+03
1 .OE+06
1 .3E+03
2.7E+03
1 .8E+03
2.0E+03
2.7E+03
5.7E+03
2.2E+04
1 .OE+06
1 .OE+06
o'
s
(continued)
-------
Table 4-10. (continued)
CAS Name
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1 ,2-
1 06-46-7 Dichlorobenzene, 1 ,4-
75-71-8 Dichlorodifluoromethane
107-06-2 Dichloroethane, 1,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1,2-
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
1 06-88-7 Epoxybutane, 1 ,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene dibromide
107-21-1 Ethylene glycol
75-21 -8 Ethylene oxide
50-00-0 Formaldehyde
98-01-1 Furfural
87-68-3 Hexachloro-1 ,3-butadiene
118-74-1 Hexachlorobenzene
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
Group
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Semi
Semi
Vol
25m
1E+04
8E+00
2E+02
8E+04
9E+04
3E+03
7E+03
2E+02
1E+02
2E+02
3E+02
3E+05 a'°
3E+02
2E+03
5E+05 a'°
1E+04
6E+01
2E+03
2E+03
5E+04
no risk
Subchronic
50 m
NM
2E+04
1E+01
3E+02
1E+05
1E+05
5E+03
1E+04
4E+02
2E+02
4E+02
5E+02
NM
NM
6E+05 a'°
NM
5E+02
3E+03
NMS
9E+05 "
2E+04b
1E+02
NM
3E+03
4E+03
9E+04
NM
NM
NM
no risk
75m
3E+04
2E+01
4E+02
2E+05
2E+05
8E+03
2E+04
6E+02
3E+02
6E+02
7E+02
8E+05 a'°
8E+02
5E+03
no risk
3E+04
2E+02
5E+03
6E+03
1E+05
no risk
Acute
25 m 50 m 75m
NM
NMA
NMA
NMA
NMA
1 E+04 2E+04 2E+04
NMA
5E+02 6E+02 9E+02
NMA
1 E+02 2E+02 2E+02
NMA
NMA
NM
NM
2E+04 2E+04 3E+04
NM
6E+03 9E+03 1 E+04
NMA
2E+03 2E+03 3E+03
1 E+04 2E+04 3E+04
NMA
NMA
NM
NMA
7E+02 1 E+03 1 E+03
NMA
NM
NM
NM
, b , b , b
no risk no risk no risk
75 m Csat
(mg/kg)
5.2E+03
1 .9E+03
1 .6E+04
1 .8E+03
2.2E+03
1 .OE+03
1 .2E+03
3.4E+03
2.7E+03
2.2E+03
2.2E+03
2.2E+03
4.8E+02
2.1 E+02
2.3E+05
3.3E+02
1 .6E+04
1 .7E+04
2.3E+05
2.3E+05
1 .3E+03
3.1 E+03
2.3E+05
8.9E+04
1 .3E+05
2.7E+04
1 .OE+03
2.3E+04
2.1 E+03
2.6E+03
o'
s
(continued)
-------
-^
to
Table 4-10. (continued)
CAS Name
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
110-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
924-16-3 Nitrosodi-n-butylamine
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
110-86-1 Pyridine
100-42-5 Styrene
Group
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Vol
25m
7E+03
4E+01
6E+04
7E+02
9E+02
2E+04
2E+04
1E+05
3E+04
2E+04
4E+03
2E+03
3E+04
4E+02
5E+02
6E+04
Subchronic
50 m
NM
NMS
1E+04
6E+01
NMS
NMS
9E+04
1E+03
1E+03
4E+04
3E+04
2E+05
5E+04
NM
2E+04
NM
5E+03
NMS
4E+03
5E+04
NM
6E+02
NMS
NMS
NM
NM
9E+02
NMS
1E+05
75m
2E+04
9E+01
1E+05
2E+03
2E+03
6E+04
4E+04
3E+05
8E+04
4E+04
8E+03
6E+03
7E+04
9E+02
1E+03
2E+05
Acute
25 m 50 m 75m
NM
NMA
NMA
2E+01 2E+01 3E+01
1 E+05 1 E+05 2E+05
NMA
4E+02 5E+02 7E+02
4E+01 6E+01 9E+01
1 E+02 2E+02 3E+02
4E+04 7E+04 9E+04
NMA
NMA
6E+03 9E+03 1 E+04
NM
3E+03 5E+03 7E+03
NM
NMA
NMA
NMA
5E+04 6E+04 7E+04
NM
NMA
NMA
NMA
NM
NM
6E+03 9E+03 1 E+04
NMA
3E+04 4E+04 5E+04
75 m Csat
(mg/kg)
6.1E+03
1 .OE+06
1 .OE+06
2.6E+01
2.3E+05
2.3E+05
2.3E+05
5.7E+03
1 .9E+03
5.4E+04
6.0E+03
5.5E+03
2.6E+04
4.0E+01
4.6E+03
2.3E+05
6.4E+02
2.3E+05
3.8E+02
1 .OE+06
1 .3E+03
4.6E+03
2.1E+03
2.3E+04
3.3E+04
1 .4E+03
1.1 E+05
2.6E+05
1 .5E+03
o'
s
(continued)
-------
Table 4-10. (continued)
CAS Name
\746-Q-\-6JCDD, 2,3,7, 8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01 -6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01 -4 Vinyl chloride
1 330-20-7 Xylenes (total)
Group
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
25m
9E+04
2E+04
4E+04
2E+04
4E+03
2E+04
2E+03
1E+03
2E+03
1E+02
5E+04
Subchronic
50 m
NM
NMS
1E+05
3E+04
7E+04
NM
NMS
NM
3E+04
NMS
7E+03
3E+04
3E+03
2E+03
3E+03
2E+02
9E+04
75m
2E+05
4E+04
9E+04
5E+04
1E+04
5E+04
4E+03
2E+03
5E+03
4E+02
1E+05
Acute
25 m 50 m 75m
NM
NMA
NMA
6E+02 8E+02 1 E+03
1 E+04 1 E+04 2E+04
NM
NMA
NM
4E+03 5E+03 8E+03
NMA
6E+03 8E+03 1 E+04
NMA
NMA
3E+03 4E+03 5E+03
NMA
2E+02 2E+02 3E+02
5E+03 7E+03 9E+03
75 m Csat
(mg/kg)
3.8E-01
2.8E+03
4.7E+03
5.9E+02
1 .7E+03
5.9E+03
2.1 E+03
1 .6E+04
2.7E+03
3.8E+03
3.4E+03
3.3E+03
2.1 E+04
1 .OE+06
5.3E+03
1 .8E+03
1 .5E+03
NM = Not modeled for land-based units.
NMA = Not modeled for acute.
NMS = Not modeled for subchronic.
no risk = the aqueous phase result exceeded ~\ million parts per million (1,000,000 mg/kg or mg/L).
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a pure, organic-phase component, the risk is less than 1 E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
0 Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2A.3 for more details.
o'
s
-------
Volume I
Section 4.0
Table 4-11. Comparison of Cw for Chronic, Subchronic, and Acute Averaging
Times for HQ = 1 for Land Application Units (mg/kg)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
107-02-8 Acrolein
79-06-1 Acrylamide
79-10-7 Acrylic acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71-43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41-7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
126-99-8 Chloro-1,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
7440-47-3 Chromium VI
7440-48-4 Cobalt
1319-77-3 Cresols (total)
98-82-8 Cumene
108-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1,2-
106-46-7 Dichlorobenzene, 1,4-
75-71-8 Dichlorodifluoromethane
107-06-2 Dichloroethane, 1,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1,2-
10061-01-5 Dichloropropene, cis-1,3-
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Metal
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Chronic
6E+03
no risk
1E+04
2E+00
NM
NM
9E+01
2E+01
NM
2E+03
8E+04
3E+02
NM
NM
3E+03
2E+02
1E+04
2E+00
4E+03
2E+04
1E+02
2E+02
1E+03
4E+02
7E+01
NM
6E+02
2E+03
NM
4E+04
8E+00
8E+04
1E+05
4E+05
4E+03
7E+01
3E+01
1E+02
1E+02
Subchronic
7E+03
b,c
no risk
3E+03
7E+00
NM
NM
8E+02
1E+02
NM
NM
3E+05
2E+02
NM
NM
NM
NM
NM
NM
NM
9E+03
4E+03
NM
4E+03
NM
3E+03
NM
3E+04
2E+03
NM
1E+05
2E+01
5E+02
3E+05
3E+05
2E+04
1E+04
1E+03
2E+02
6E+02
Acute
NM
3E+05a'C
NM
2E-01
NM
NM
5E+02
NM
NM
8E+03
NM
2E+02
NM
NM
NM
NM
NM
NM
NM
2E+04
1E+03
NM
NM
NM
6E+02
NM
NM
NM
NM
NM
NM
NM
NM
3E+04
NM
1E+03
NM
3E+02
NM
csa,
(mg/kg)
3.3E+05
2.3E+05
2.3E+05
5.0E+04
1.5E+05
2.4E+05
1.8E+04
1.7E+03
1.0E+04
1.0E+06
1.0E+06
1.8E+03
2.4E+02
1.5E+02
1.0E+06
6.3E+03
4.5E+03
1.1E+03
1.0E+06
1.3E+03
2.7E+03
1.8E+03
2.0E+03
2.7E+03
5.7E+03
2.2E+04
1.0E+06
1.0E+06
5.2E+03
1.9E+03
1.6E+04
1.8E+03
2.2E+03
1.0E+03
1.2E+03
3.4E+03
2.7E+03
2.2E+03
2.2E+03
(continued)
4-44
-------
Volume I
Section 4.0
Table 4-11. (continued)
CAS Name
10061-02-6 Dichloropropene, trans-1,3-
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
122-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
106-88-7 Epoxybutane, 1,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
110-80-5 Ethoxyethanol, 2-
100-41-4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21-8 Ethylene oxide
50-00-0 Formaldehyde
98-01-1 Furfural
87-68-3 Hexachloro-1,3-butadiene
118-74-1 Hexachlorobenzene
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead*
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
110-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
Group
Vol
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Semi
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Chronic
1E+02
NM
NM
2E+05
NM
1E+04
2E+03
2E+05
a,D
5E+05
8E+04
3E+01
NM
6E+01
8E+03
7E+03
NM
NM
NM
1E+04
NM
3E+05
8E+03
3E+01
no risk
2E+04
3E+04
2E+02
7E+02
4E+05
2E+04
9E+04
2E+05
NM
4E+03
NM
1E+04
3E+02
5E+03
3E+04
NM
2E+00
Subchronic
7E+02
NM
NM
5E+05a'C
NM
8E+02
6E+03
NM
a,c
no risk
2E+04
7E+01
NM
7E+03
7E+03
2E+04
NM
NM
NM
b
no risk
NM
NM
3E+04
1E+01
NM
NM
8E+04
2E+03
5E+03
9E+04
7E+04
3E+05
5E+04
NM
4E+04
NM
5E+03
NM
1E+04
1E+05
NM
6E+02
Acute
NM
NM
NM
1E+04
NM
1E+04
NM
4E+03
3E+04
NM
NM
NM
NM
2E+03
NM
NM
NM
NM
9E+05
NM
NM
NM
8E+00
4E+05a'C
NM
7E+02
2E+02
7E+02
2E+05
NM
NM
1E+04
NM
1E+04
NM
NM
NM
NM
2E+05
NM
NM
csa,
(mg/kg)
2.2E+03
4.8E+02
2.1E+02
2.3E+05
3.3E+02
1.6E+04
1.7E+04
2.3E+05
2.3E+05
1.3E+03
3.1E+03
2.3E+05
8.9E+04
1.3E+05
2.7E+04
1.0E+03
2.3E+04
2.1E+03
2.6E+03
6.1E+03
1.0E+06
1.0E+06
2.6E+01
2.3E+05
2.3E+05
2.3E+05
5.7E+03
1.9E+03
5.4E+04
6.0E+03
5.5E+03
2.6E+04
4.0E+01
4.6E+03
2.3E+05
6.4E+02
2.3E+05
3.8E+02
1.0E+06
1.3E+03
4.6E+03
(continued)
4-45
-------
Volume I
Section 4.0
Table 4-11. (continued)
CAS Name
924-16-3 Nitrosodi-n-butylamine
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
110-86-1 Pyridine
100-42-5 Styrene
1746-01-6 TCDD, 2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1,1,2,2-
127-18-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1,2,4-
71-55-6 Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01-6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121-44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1 330-20-7 Xylenes (total)
Group
Vol
Vol
Semi
Semi
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Chronic
6E+00
5E-01
NM
NM
2E+03
8E+03
5E+05
NM
6E+02
2E+02
3E+03
2E+04
NM
8E+05
NM
3E+04
1E+02
1E+03
2E+04
4E+02
1E+04
2E+04
1E+01
3E+04
Subchronic
NM
NM
NM
NM
2E+03
NM
4E+05
NM
NM
1E+05
4E+04
8E+04
NM
NM
NM
5E+04
NM
8E+03
9E+04
2E+03
4E+03
7E+03
1E+03
9E+04
Acute
NM
NM
NM
NM
2E+04
NM
2E+05
NM
NM
NM
1E+03
2E+04
NM
NM
NM
1E+04
NM
1E+04
NM
NM
1E+04
NM
1E+03
8E+03
csa,
(mg/kg)
2.1E+03
2.3E+04
3.3E+04
1.4E+03
1.1E+05
2.6E+05
1.5E+03
3.8E-01
2.8E+03
4.7E+03
5.9E+02
1.7E+03
5.9E+03
2.1E+03
1.6E+04
2.7E+03
3.8E+03
3.4E+03
3.3E+03
2.1E+04
1.0E+06
5.3E+03
1.8E+03
1.5E+03
no risk = the aqueous phase result exceeded 1 million parts per million (1,000,000 mg/kg or mg/L).
NM = Not modeled; if all 3 columns say NM, the chemical was not modeled for land-based unit. If only one or two
columns say NM, the chemical was not modeled for that averaging time.
* For lead, this value is Child aged 3-7 years.
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a
pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a
pure, organic-phase component, the risk is less than 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
c Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent
is modeled in an organic waste matrix. The organic-phase results
are shown in Volume III. See Section 3.2.4.3 for more details.
4-46
-------
Volume I
Section 4.0
Table 4-12. Comparison of Cw for Chronic, Subchronic, and Acute Averaging
Times for HQ = 1 for Wastepiles (mg/kg)
CAS Name
75-07-0 Acetaldehyde
67-64-1 Acetone
75-05-8 Acetonitrile
1 07-02-8 Acrolein
79-06-1 Acrylamide
79-1 0-7 Acrylic acid
107-13-1 Acrylonitrile
107-05-1 Allyl chloride
62-53-3 Aniline
7440-38-2 Arsenic
7440-39-3 Barium
71 -43-2 Benzene
92-87-5 Benzidine
50-32-8 Benzo(a)pyrene
7440-41 -7 Beryllium
75-27-4 Bromodichloromethane
75-25-2 Bromoform (Tribromomethane)
106-99-0 Butadiene, 1,3-
7440-43-9 Cadmium
75-15-0 Carbon disulfide
56-23-5 Carbon tetrachloride
1 26-99-8 Chloro-1,3-butadiene, 2- (Chloroprene)
108-90-7 Chlorobenzene
124-48-1 Chlorodibromomethane
67-66-3 Chloroform
95-57-8 Chlorophenol, 2-
7440-47-3 Chromium VI
7440-48-4 Cobalt
131 9-77-3 Cresols (total)
98-82-8 Cumene
1 08-93-0 Cyclohexanol
96-12-8 Dibromo-3-chloropropane, 1,2-
95-50-1 Dichlorobenzene, 1,2-
106-46-7 Dichlorobenzene, 1,4-
75-71-8 Dichlorodifluoromethane
1 07-06-2 Dichloroethane, 1,2-
75-35-4 Dichloroethylene, 1,1-
78-87-5 Dichloropropane, 1,2-
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
Group
Vol
Vol
Vol
Vol
Semi
Semi
Vol
Vol
Semi
Metal
Metal
Vol
Semi
Semi
Metal
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Metal
Metal
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Chronic
2E+04
no risk
5E+04
1E+01
NM
NM
4E+02
9E+01
NM
2E+03
1E+05
2E+03
NM
NM
4E+03
2E+03
3E+05
4E+00
5E+03
5E+04
5E+02
8E+02
1E+04
6E+03
4E+02
NM
8E+02
2E+03
NM
8E+04
4E+01
4E+05
5E+05
no risk
8E+03
5E+02
9E+01
9E+02
1E+03
1E+03
Sub-
chronic
5E+03
no risk
3E+03
7E+00
NM
NM
7E+02
6E+01
NM
NM
2E+05
2E+02
NM
NM
NM
NM
NM
NM
NM
4E+03
4E+03
NM
8E+03
NM
4E+03
NM
2E+04
1E+03
NM
3E+04
2E+01
4E+02
2E+05
2E+05
8E+03
2E+04
6E+02
3E+02
6E+02
7E+02
Acute
NM
2E+05
NM
2E-01
NM
NM
4E+02
NM
NM
3E+03
NM
1E+02
NM
NM
NM
NM
NM
NM
NM
7E+03
9E+02
NM
NM
4E+02
NM
NM
NM
NM
NM
NM
NM
NM
2E+04
NM
9E+02
NM
2E+02
NM
NM
csa,
(mg/kg)
3.3E+05
2.3E+05
2.3E+05
5.0E+04
1.5E+05
2.4E+05
1.8E+04
1.7E+03
1.0E+04
1.0E+06
1.0E+06
1.8E+03
2.4E+02
1.5E+02
1.0E+06
6.3E+03
4.5E+03
1.1E+03
1.0E+06
1.3E+03
2.7E+03
1.8E+03
2.0E+03
2.7E+03
5.7E+03
2.2E+04
1.0E+06
1.0E+06
5.2E+03
1.9E+03
1.6E+04
1.8E+03
2.2E+03
1.0E+03
1.2E+03
3.4E+03
2.7E+03
2.2E+03
2.2E+03
2.2E+03
(continued)
4-47
-------
Volume I
Section 4.0
Table 4-12. (continued)
CAS Name
57-97-6 Dimethylbenz(a)anthracene, 7,12-
121-14-2 Dinitrotoluene, 2,4-
123-91-1 Dioxane, 1,4-
1 22-66-7 Diphenylhydrazine, 1,2-
106-89-8 Epichlorohydrin
1 06-88-7 Epoxybutane, 1,2-
111-15-9 Ethoxyethanol acetate (R-R), 2-
11 0-80-5 Ethoxyethanol, 2-
100-41 -4 Ethylbenzene
106-93-4 Ethylene Dibromide
107-21-1 Ethylene glycol
75-21 -8 Ethylene oxide
50-00-0 Formaldehyde
98-01-1 Furfural
87-68-3 Hexachloro-1,3-butadiene
118-74-1 Hexachlorobenzene
77-47-4 Hexachlorocyclopentadiene
67-72-1 Hexachloroethane
78-59-1 Isophorone
7439-92-1 Lead
7439-96-5 Manganese
7439-97-6 Mercury
67-56-1 Methanol
110-49-6 Methoxyethanol acetate (R-R), 2-
109-86-4 Methoxyethanol, 2-
74-83-9 Methyl bromide (Bromomethane)
74-87-3 Methyl chloride (Chloromethane)
78-93-3 Methyl ethyl ketone
108-10-1 Methyl isobutyl ketone
80-62-6 Methyl methacrylate
1634-04-4 Methyl tert-butyl ether
56-49-5 Methylcholanthrene, 3-
75-09-2 Methylene chloride
68-12-2 N,N-Dimethylformamide
11 0-54-3 n-Hexane
930-55-2 N-Nitrosopyrrolidine
91-20-3 Naphthalene
7440-02-0 Nickel
98-95-3 Nitrobenzene
79-46-9 Nitropropane, 2-
Group
Semi
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Semi
Semi
Semi
Vol
Semi
Metal
Metal
Metal
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Metal
Semi
Vol
Chronic
NM
NM
i a'D
no risk
NM
5E+04
1E+04
a b
8E+05
no risk
no risk
4E+02
NM
2E+02
3E+04
1E+05
NM
NM
NM
7E+05
NM
3E+05
1E+04
5E+02
no risk
9E+04
1E+05
5E+02
2E+03
no risk
1E+05
5E+05
no risk
NM
2E+04
NM
1E+05
2E+03
2E+04
4E+04
NM
2E+01
Sub-
chronic
NM
NM
8E+05a'C
NM
8E+02
5E+03
NM
no risk
3E+04
2E+02
NM
5E+03
6E+03
1E+05
NM
NM
NM
b
no risk
NM
NM
2E+04
9E+01
NM
NM
1E+05
2E+03
2E+03
6E+04
4E+04
3E+05
8E+04
NM
4E+04
NM
8E+03
NM
6E+03
7E+04
NM
9E+02
Acute
NM
NM
3E+04
NM
1E+04
NM
3E+03
3E+04
NM
NM
NM
NM
1E+03
NM
NM
NM
NM
D
no risk
NM
NM
NM
3E+01
2E+05
NM
7E+02
9E+01
3E+02
9E+04
NM
NM
1E+04
NM
7E+03
NM
NM
NM
NM
7E+04
NM
NM
csa,
(mg/kg)
4.8E+02
2.1E+02
2.3E+05
3.3E+02
1.6E+04
1.7E+04
2.3E+05
2.3E+05
1.3E+03
3.1E+03
2.3E+05
8.9E+04
1.3E+05
2.7E+04
1.0E+03
2.3E+04
2.1E+03
2.6E+03
6.1E+03
1.0E+06
1.0E+06
2.6E+01
2.3E+05
2.3E+05
2.3E+05
5.7E+03
1.9E+03
5.4E+04
6.0E+03
5.5E+03
2.6E+04
4.0E+01
4.6E+03
2.3E+05
6.4E+02
2.3E+05
3.8E+02
1.0E+06
1.3E+03
4.6E+03
(continued)
4-48
-------
Volume I
Section 4.0
Table 4-12. (continued)
CAS Name
924-16-3 Nitrosodi-n-butylamine
55-18-5 Nitrosodiethylamine
108-95-2 Phenol
85-44-9 Phthalic anhydride
75-56-9 Propylene oxide
110-86-1 Pyridine
1 00-42-5 Styrene
1746-01-6 TCDD, 2,3,7,8-
630-20-6 Tetrachloroethane, 1,1,1,2-
79-34-5 Tetrachloroethane, 1 , 1,2,2-
127-1 8-4 Tetrachloroethylene
108-88-3 Toluene
95-53-4 Toluidine, o-
76-13-1 Trichloro-1,2,2-trifluoroethane, 1,1,2-
120-82-1 Trichlorobenzene, 1,2,4-
71-55-6Trichloroethane, 1,1,1-
79-00-5 Trichloroethane, 1,1,2-
79-01-6 Trichloroethylene
75-69-4 Trichlorofluoromethane
121 -44-8 Triethylamine
7440-62-2 Vanadium
108-05-4 Vinyl acetate
75-01-4 Vinyl chloride
1 330-20-7 Xylenes (total)
Group
Vol
Vol
Semi
Semi
Vol
Vol
Vol
Semi
Vol
Vol
Vol
Vol
Semi
Vol
Semi
Vol
Vol
Vol
Vol
Vol
Metal
Vol
Vol
Vol
Chronic
4E+01
3E+00
NM
NM
8E+03
3E+04
no risk
NM
5E+03
2E+03
2E+04
2E+05
NM
no risk
NM
2E+05
1E+03
7E+03
5E+04
4E+03
1E+04
8E+04
3E+01
3E+05
Sub-
chronic
NM
NM
NM
NM
1E+03
NM
2E+05
NM
NM
2E+05
4E+04
9E+04
NM
NM
NM
5E+04
NM
1E+04
5E+04
4E+03
2E+03
5E+03
4E+02
1E+05
Acute
NM
NM
NM
NM
1E+04
NM
5E+04
NM
NM
NM
1E+03
2E+04
NM
NM
NM
8E+03
NM
1E+04
NM
NM
5E+03
NM
3E+02
9E+03
csa,
(mg/kg)
2.1E+03
2.3E+04
3.3E+04
1.4E+03
1.1E+05
2.6E+05
1.5E+03
3.8E-01
2.8E+03
4.7E+03
5.9E+02
1.7E+03
5.9E+03
2.1E+03
1.6E+04
2.7E+03
3.8E+03
3.4E+03
3.3E+03
2.1E+04
1.0E+06
5.3E+03
1.8E+03
1.5E+03
no risk = the aqueous phase result exceeded 1 million parts per million (1,000,000 mg/kg or mg/L).
NM = Not modeled; if all 3 columns say NM, the chemical was not modeled for land-based unit. If only one or two
columns say NM, the chemical was not modeled for that averaging time.
* For lead, this value is Child aged 3-7 years.
a Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a
pure, organic-phase component, the risk exceeds 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
b Aqueous-phase result exceeds solubility or Csat at a neutral pH and temperature of 25°C. When modeled as a
pure, organic-phase component, the risk is less than 1E-5 or HQ = 1.
See Section 3.2.4.3 for more details.
c Organic-phase emissions greater than aqueous-phase emissions; therefore, the Cw will be lower if this constituent
is modeled in an organic waste matrix. The organic-phase results are shown in Volume III. See Section 3.2.4.3 for
more details.
4-49
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Volume I Section 5.0
5.0 Characterization of Significant Findings
5.1 Introduction
The 1998 Air Characteristic Study began evaluating the merits of developing an air
characteristic by integrating the results of the regulatory analysis, occurrence evaluation, and risk
analysis. The purpose of combining these three analyses in the 1998 study was to provide
preliminary information on where gaps in regulatory coverage may exist, what concentrations in
waste are protective for direct inhalation risk, and, to a limited extent, the occurrence of these
constituents in nonhazardous waste. Because integrating these analyses is an important step in
identifying gaps and determining the significance of risk results, this section draws on the results
of the revised risk assessment and the regulatory gaps analysis and occurrence analysis done for
the May 1998 Air Characteristic Study.
This section presents an overview of the significant findings and begins to construct a
comparison of the results to focus on potential gaps and the associated risks. This integration
will assist in identifying areas warranting further study. This section serves two primary
purposes: (1) to focus on the potential need to develop an air characteristic that would expand
the present definition of hazardous waste, and (2) to evaluate the effectiveness of current RCRA
regulations in reducing air emissions once a waste is defined as hazardous.
To address these dual purposes, Section 5.2 focuses on the extent to which the current
RCRA hazardous waste characteristics and listings or CAA coverage already capture wastes that
might pose hazardous air emissions, and Section 5.3 evaluates the extent to which current RCRA
regulations would reduce the risks of air emissions from waste if an air characteristic were
promulgated. This section examines the risks and gaps associated with wastewater tanks
independently from the land-based waste management units. Results from this analysis indicate
that the concentrations in tanks that would be protective of human health are considerably lower
than the concentrations in waste that would be protective in the land-based units. The division
between tanks and land-based units is also apparent in the level of direct air emission controls
required.
This section focuses on a subset of the constituents addressed in the risk analysis.
Constituents discussed in this chapter are primarily those that have protective concentrations in
wastes of 100 ppm or less at a risk of 10"5 or HQ of 1 and a distance of 150 m from the site. This
is only for presentation purposes and does not exclude other risk levels, distances, or
constituents from consideration in determining the need for an air characteristic.
Aqueous-phase risk results presented in this section that exceed solubility or soil
saturation concentrations under standard conditions (temperature of 20-25 °C and neutral pH) are
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Volume I
Section 5.0
footnoted; also noted is whether pure component modeled using organic phase produced risks or
hazard quotients (HQs) over the target risk level of 10"5 or target HQ of 1. The difference
between aqueous-phase and organic-phase emissions modeling is discussed in Sections 3 and 4.
5.2 Gaps in Constituent Coverage
In keeping with the charge of this study to determine the need for an air characteristic, the
basis for constituent coverage under both RCRA and CAA was evaluated and compared to the
constituents addressed in this study.
5.2.1 RCRA Gaps in Constituent Coverage
In RCRA, hazardous wastes are defined as solid wastes that exhibit a characteristic of
hazardous waste or are listed as hazardous wastes. In recent years, the listing process has been
based on multimedia considerations that include the investigation of air pathway risks.
Characteristics more broadly define hazardous wastes because they are not limited to particular
waste management processes. Currently, only one of the characteristics is based on constituent
toxicity, the Toxicity Characteristic (TC). The TC was designed to identify wastes that pose
significant potential risk through contamination of groundwater. The relationship of the
constituents in this study to both the TC and listings was explored to ascertain the degree to
which the 105 constituents may already be regulated as hazardous wastes.
An investigation of
the TC list identified that 22
TC constituents overlap with
the constituents in this study.
A direct comparison was
made between the
milligram/liter TC level in
the regulations to the waste
concentration results
for wastewaters in
tanks. For
nonwastewaters,
except metals,1 EPA
used the Organic
Leaching Model to
derive a waste
concentration in parts
per million from the
regulatory leachate
level. This
Tank Waste Levels That Are More Stringent than TC Level
(mg/L)
Constituent TC level Aerated Nonaerated
Chlorobenzene
Cresols, total
100
200
99
160
Land-based Unit Waste Levels That Are More Stringent Than TC
Level for Chronic Exposures (mg/kg)
Constituent
Chlorobenzene
TC
(Waste)
270,000
LAU
Waste
2,000a
WP
Waste
25,000b
LF
Waste
14,000a
1,1-Dichloroethylene 74 50 -
a These values exceed the soil saturation concentration; pure component results in risk at or above 10"5.
b These values exceed the soil saturation concentration; pure component results in risk below 10"5.
1 Metals were calculated using empirical leaching data.
5-2
-------
Volume I Section 5.0
comparison, shown
A j- A LAU and WP Waste Levels That Are More Stringent Than TC Level
in Appendix A, . "
... , , for Subchronic Exposures
indicates that the
current TC levels are
generally protective
of potential direct
TC LAU WP
Constituent (Waste) Waste Waste Scenario
Chlorobenzene 270,000 4,000a 8,000a Subchronic
" These values exceed the soil saturation concentration; pure component results in risk at or above 10"5.
inhalation risks. In
other words, the
waste would already
be hazardous and
potentially subject to air emission controls at a concentration lower than the concentration that
would present a direct inhalation risk. Four constituents had protective waste concentrations
lower than the TC or TC-derived waste concentration. Two constituents had TC levels that may
not be protective of air pathway risks for tanks. Two constituents had waste concentrations more
stringent than TC levels for land application units (LAUs); one of these had waste concentrations
more stringent than TC levels in all the land-based units. The magnitude of the difference
between the TC and the estimated air characteristic, Cw, varied according to the waste
management unit and the constituent. In some circumstances, the difference was negligible, such
as chlorobenzene in aerated tanks. The largest difference was less than a factor of 135 for
chlorobenzene in LAUs.
A comparison was then made of the constituents that are associated with a hazardous
waste listing. Listed wastes associated with constituents examined in this study were
investigated using the best available national-level waste characterization data. Because of data
limitations, the listed waste code data provide a
rough representation of the extent to which
constituents in this study may be present in listed
waste. The comparison was done to identify study
constituents that did not appear to ever be
associated with a listing or had very few listing
associations. It can be argued that constituents
that are associated with multiple listings are the
least likely to present gaps. Sixteen of the study
constituents were neither associated with a listing nor on the TC list. Two of these constituents
had concentrations in all three types of tanks less than 100 ppm.
5.2.2 Clean Air Act Gaps in Constituent Coverage
Under the CAA, most direct regulation of air toxics is applied to those constituents on the
list of hazardous air pollutants (HAPs). Of the 105 constituents addressed in this study, 84 are
HAPs. The HAP list is strongly weighted to include the most toxic, volatile, and persistent of the
chemicals known to be released to air from industrial operations. The CAA program controls
HAPs under the authority of Section 112 for major sources that have been designated as source
Two Constituents Not Associated with
a Listing or the TC with Cws in Tanks
Less than 100 ppm
# 1,3- Butadiene
# Cyclohexanol
2 TC levels could change in the future; if a TC were significantly raised, it might no longer be protective
of air risks.
-------
Volume I
Section 5.0
categories. There is the possibility for a gap if the constituent is not on the HAP list. Twenty-
one of the constituents addressed in this study are not on the HAP list. Of the 21 that are not
HAPs, 10 had Cw's in tanks less than 100 mg/L and 4 had Cw's in land-based units less than
100 mg/kg. Of those that are on the HAP list, 25 had concentration levels (Cw's) in tanks less
than 100 mg/L and 8 had Cw's less than 100 ppm in land-based units. The comparison of Cw's
for the land units considered subchronic and acute exposures in addition to chronic exposures.
The potential exists for a
constituent to be on the HAP list but not
subject to CAA controls if it is contained
in a waste that is managed at (1) a facility
that is not an identified source category,
(2) a facility that is in a source category
but is not a major or area source, or (3) a
facility that is in a source category and is
a major source but the unit does not have
a MACT standard. It would be difficult
to determine the extent to which a
constituent may be managed under one of
these situations and not controlled under the
5.2.3 Summary of Gaps in Regulation
Five Constituents with Less than Four Associated
Listings, Not on the TC, and Not a HAP with Cw's
in Tanks Less than 100 mg/L
Constituent Cw
Nitrosodiethylamine 0.1 (nonaerated)
Bromodichloromethane 20 (aerated)
Cyclohexanol 3 (nonaerated)
Chlorodibromomethane 20 (aerated)
Nitrosodi-«-butylamine 0.3 (aerated)
MACT program.
It is apparent that the most significant gaps in regulatory coverage exist if the constituent
is not a HAP, is not on the TC list, and is not associated with a listing. Out of the evaluated
constituents, two were not regulated by any of these authorities: 3,4-dimethylphenol and
cyclohexanol. The lowest Cw for cyclohexanol was 3 mg/L for nonaerated tanks. As noted
previously, a Cw was not calculated for 3,4-dimethylphenol because of the lack of data
appropriate for developing a health benchmark.
5.3 Air Emission Controls Under RCRA
This section evaluates the likelihood that air emissions from wastes subject to RCRA by
an air characteristic would be reduced by current RCRA controls. Although there are provisions
in RCRA for controlling air emissions for the purpose of reducing the resulting human health
risk, qualifying factors place certain waste management units outside the scope of regulatory
coverage.
5.3.1 Air Emission Controls for Tanks Under RCRA
It is apparent from the risk analysis that wastewater tanks are of most concern for
risks from the inhalation pathway. This analysis focuses on the RCRA Subpart CC rules
because they apply most directly to tanks. Subpart CC design requirements control air emissions
from tanks, surface impoundments, and containers in which hazardous wastes have been placed.
Current exclusions to the applicability of RCRA raise the potential that an air characteristic could
5-4
-------
Volume I Section 5.0
regulate wastes as hazardous, but current RCRA regulations may not reduce air emissions. Two
of these exemptions are noteworthy in this chapter.
Foremost among the exclusions is the exemption of wastewater treatment tanks. Because
available data indicate that wastewater treatment systems manage approximately 89 percent of
industrial nonhazardous wastes, a large proportion of wastes that might be newly identified as
hazardous by an air characteristic would escape regulation for air releases under RCRA Subpart
CC rules (although some of these may be regulated by CAA requirements).
Another Subpart CC exclusion are wastes below the 500 ppm threshold for total organic
content. Approximately 35 constituents were identified in the risk analysis as having protective
waste concentrations in tanks of less than 100 ppm. Because the 500-ppm limit does not apply
on a constituent-by-constituent basis and data are limited on the total volatiles that are typically
co-managed, it is difficult to forecast the significance of this finding. Additionally, this 500-ppm
threshold limit was established to be protective of human health and the environment.
Table 5-1 compares risk and occurrence data for the constituents that had a protective
concentration in tanks of less than 100 ppm. This table indicates the protective waste
concentration, if the constituent is a HAP, the TC level, if the TC level was protective, the
number of listed waste associations, the total TRI releases and off-site transfers, and the
estimated production volume. In addition, the table shows the number of two-digit SIC codes
associated with the use of each constituent.
5.3.2 Air Emission Controls for Land Units Under RCRA
Air emissions from land-based units (i.e., landfills, land application units, wastepiles) are
controlled directly or indirectly by land disposal restrictions and waste management unit
standards. The protective concentrations calculated in the risk assessment are higher for land-
based units than those for tanks, implying (without consideration of controls) that the risks
associated with these units may be lower relative to those associated with tanks.
Land-based Unit Waste Levels That Are More Stringent
Than UTS Level for Chronic Exposures (mg/kg)
UTS LAU WP LF
Constituent (Waste) Waste Waste Waste
Nitrosodiethylamine 30 0.8 7 6
Nitrosodi-n-butylamine 20 10
In general, the land
disposal restriction treatment
standards will greatly reduce
the concentration of organics
and will require the
stabilization of metal-bearing
wastes (reducing the wind-
dispersal characteristics) of any
regulated hazardous wastes
placed in land-based units. A comparison between the LDRs and the protective concentrations in
waste was made and indicates that the treatment standards are not always below the levels at
which there are potential air risks. Two constituents had concentrations in waste for chronic
exposures that were below the LDR treatment levelsone by more than tenfold. No constituents
had concentrations in waste that were below the LDR treatment levels for acute or subchronic
exposures. The tables contained in Appendix A show this comparison for each constituent.
5-5
-------
Oi
Table 5-1. Regulatory, Occurrence, and Risk Comparison for Tanks
Constituents with Waste Concentrations Less than 100 ppm
CAS Name
1746-01-6 TCDD, 2,3,7,8-
55-18-5 Nitrosodiethylamine
924-16-3 Nitrosodi-n-butylamine
107-02-8 Acrolein
79-46-9 Nitropropane, 2-
106-99-0 Butadiene, 1,3-
77-47-4 Hexachlorocyclopentadiene
7439-97-6 Mercury
75-01-4 Vinyl chloride
106-93-4 Ethylene Dibromide
108-93-0 Cyclohexanol
75-35-4 Dichloroethylene, 1,1-
107-05-1 Allyl chloride
118-74-1 Hexachlorobenzene
75-21-8 Ethylene oxide
10061-01-5 Dichloropropene, cis-1,3-
10061-02-6 Dichloropropene, trans-1,3-
67-66-3 Chloroform
79-34-5 Tetrachloroethane, 1,1,2,2-
107-13-1 Acrylonitrile
107-06-2 Dichloroethane, 1,2-
56-23-5 Carbon tetrachloride
95-57-8 Chlorophenol, 2-
Waste
Concentration
(mo/kg)
5.E-033
1.E-01
3.E-01
3.E-01
4.E-01
4.E-01
7.E-01
2.E+003
2.E+00
2.E+00
3.E+00
4.E+00
4.E+00
5.E+00
7.E+00
8.E+00
1.E+01
1.E+01
1.E+01
1.E+01
1.E+01
1.E+01
2.E+01
Unit Type
ATANK
NTANK
ATANK
ATANK
ATANK
ATANK
ATANK
ATANK
ATANK
ATANK
NTANK
ATANK
ATANK
ATANK
NTANK
ATANK
ATANK
ATANK
ATANK
NTANK
ATANK
ATANK
ATANK
Scenario
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Chronic
Total1995
TC TRI Releases
(leachate) Number of and Off-site
Level Listed Waste Transfers
HAP (mg/kg) Associations (Ib)
H
-
H
H
H
H
H 0.2
H 2E-01
H
-
7E-01
H
H 0.13
H
H
H
H
H
H
0.5
H 5E-01
-
11
2
2
2
2
0
9
24
13
5
0
8
3
12
3
3
3
27
13
7
13
18
4
..
-
2.1E+05
3.5E+04
1.0E+07
3.0E+05
1.3E+06
8.5E+04
-
-
4.7E+05
7.2E+04
-
-
1.3E+07
2.4E+06
8.3E+06
1.9E+07
1.6E+06
Estimated
Annual
Production
(Ib)
..
-
6.1E+07
5.0E+03
3.1E+09
7.7E+06
1.4E+10
-
3.0E+03
6.7E+04
5.3E+05
5.7E+08
1.0E+06
1.0E+06
4.3E+07
1.0E+06
3.5E+08
1.0E+10
9.6E+06
SIC
Frequency
3
2
13
5
7
12
10
7
5
2
1
9
3
3
10
9
4
10
13
(continued)
-------
CAS Name
87-68-3 Hexachloro-1,3-butadiene
78-87-5 Dichloropropane, 1,2-
75-27-4 Bromodichloromethane
74-83-9 Methyl bromide (Bromomethane)
124-48-1 Chlorodibromomethane
79-00-5 Trichloroethane, 1,1,2-
71-43-2 Benzene
126-99-8 Chloro-1,3-butadiene, 2- (Chloroprene)
91-20-3 Naphthalene
630-20-6 Tetrachloroethane, 1,1,1,2-
98-95-3 Nitrobenzene
108-90-7 Chlorobenzene
a These values exceed the solubility; pure component
Waste
Concentration
(mg/kg)
2.E+013
2.E+01
2.E+01
2.E+01
2.E+01
2.E+01
3.E+01
3.E+01
3.E+013
4.E+01
1.E+02
1.E+02
results in risk
Table 5-1.
Unit Type
ATANK
ATANK
ATANK
ATANK
ATANK
ATANK
ATANK
ATANK
ATANK
ATANK
NTANK
ATANK
below 10'5.
(continued)
Scenario HAP
Chronic H
Chronic
Chronic
Chronic H
Chronic
Chronic H
Chronic H
Chronic H
Chronic H
Chronic
Chronic H
Chronic H
TotaM995
TC TRI Releases Estimated
(leachate) Number of and Off-site Annual
Level Listed Waste Transfers Production SIC
(mg/kg) Associations (Ib) (Ib) Frequency
0.5 8
4 2.9E+04 O.OE+00 13
1
7 2.6E+06 4.5E+07 11
1
14
5E-01 44 1.4E+07 6.1E+09 13
3 1.7E+06 8.4E+04 3
22
12
2 15
100 15
Volume I
^
0,
-------
Volume I Section 5.0
Table 5-2 compares risk and occurrence data for the constituents that had a protective
concentration in tanks of less than 100 ppm. This table indicates the protective waste
concentration, if the constituent is a HAP, the TC level, if the TC level was protective, the
number of listed waste associations, the total TRI releases and off-site transfers, and the
estimated production volume. In addition, the table shows the number of two-digit SIC codes
associated with the use of each constituent.
5-8
-------
VO
Table
CAS Name
107-02-8 Acrolein
55-18-5 Nitrosodiethylamine
79-46-9 Nitropropane, 2-
106-99-0 Butadiene, 1,3-
7439-97-6 Mercury
924-16-3 Nitrosodi-n-butylamine
108-93-0 Cyclohexanol
75-01-4 Vinyl chloride
107-05-1 Allyl chloride
75-35-4 Dichloroethylene, 1,1-
106-93-4 Ethylene dibromide
5-2. Regulatory, Occurrence, and Risk Comp
Constituents with Waste Concentrations
Waste
Concentration
(mg/kg) Unit Type Scenario HAP
2.E-01 WP Acute H
8.E-01 LAU Chronic
3.E+00 LAU Chronic H
4.E+00 LAU Chronic H
8.E+00 LAU Acute H
1.E+01 LAU Chronic
2.E+01 LAU Chronic
2.E+01 LAU Chronic H
4.E+01 LAU Chronic H
5.E+01 LAU Chronic
6.E+01 LAU Chronic H
74-83-9 Methyl bromide (Bromomethane) 9.E+01 WP Acute H
arisen lor Land-based Units
Less than 100 ppm
Total 1995
TRI
TC Releases
(waste) Number of and Off-site
Level Listed Waste Transfers
(mg/kg) Associations (Ib)
2 2.1E+05
2
4 3.5E+04
0 1.0E+07
4 18 3.0E+05
2
0
10 11 1.3E+06
3 4.7E+05
70 11
5 8.5E+04
7 2.6E+06
0"
^ .
s
3
Estimated
Annual
Production SIC
(Ib) Frequency
6.1E+07 13
3
5.0E+03 5
3.1E+09 7
7.7E+06 12
2
3.0E+03 5
1.4E+10 10
5.3E+05 1
6.7E+04 2
7
4.5E+07 11
£
0
*-(.
i
0,
-------
Volume I Section 6.0
6.0 References
Agency for Toxic Substances and Disease Registry (ATSDR). 1999. Minimal Risk Levels
(MRLs) for Hazardous Substances. http://atsdrl.atsdr.cdc.gov:8080/mrls.html
Bailey, Robert G., Peter E. Avers, Thomas King, W. Henry McNab, eds. 1994. Ecoregions and
subregions of the United States (map). Washington D.C.; U.S. Geological Survey. Scale
1:7,500,000; colored. Accompanied by a supplementary table of map unit descriptions
compiled and edited by McNab, W. Henry, and Bailey, Robert G. Prepared for the U.S.
Department of Agriculture, Forest Service, http://www.epa.gov/docs/grdwebpg/bailey/
CalEPA (California Environmental Protection Agency). 1998. Technical Support Document for
the Determination of Acute Reference Exposure Levels for Airborne Toxicants, Scientific
Review Panel Draft. Office of Environmental Health Hazard Assessment, Air
Toxicology and Epidemiology Section, Berkeley, CA.
http ://www. oehha. org/scientific/getdr els. html
Environmental Research and Technology. 1983. Land Treatment Practices in the Petroleum
Industry. American Petroleum Institute, Washington, DC.
EQM (Environmental Quality Management, Inc.,) and E.H. Pechan & Associates. 1993.
Evaluation of Dispersion Equations in Risk Assessment Guidance for Super fund (RAGS):
Volume I - Human Health Evaluation Manual. Prepared for U. S. Environmental
Protection Agency, Office of Emergency and Remedial Response, Toxics Integration
Branch, Washington, DC.
Martin, J.P., R.C. Sims, and J. Matthews. 1986. Review and Evaluation of Current Design and
Management Practices for Land Treatment Units Receiving Petroleum Wastes.
EPA/600/J-86/264. U.S. Environmental Protection Agency, Robert S. Ken-
Environmental Research Laboratory, Ada, OK.
Myers, L. (RTI) 1998. Personal communication with A. Lutes, RTI. March 16.
NOAA (National Oceanic and Atmospheric Administration). 1992. International Station
Meteorological Climate Summary, Version 2.0. CD-ROM. National Climatic Data
Center. Asheville, NC. June.
Reed, S.C., andR.W. Crites. 1984. Handbook of Land Treatment Systems for Industrial and
Municipal Wastes. Noyes Publications, Park Ridge, NJ.
6-1
-------
Volume I Section 6.0
Shroeder, K., R. Clickner, and E. Miller. 1987. Screening Survey of Industrial Subtitle D
Establishments. Draft Final Report. Westat, Inc., Rockville, MD, for U.S. EPA Office of
Solid Waste. EPA Contract 68-01-7359. December.
U.S. EPA (Environmental Protection Agency). 1985a. Compilation of Air Pollutant Emission
Factors, Volume I: Stationary Point and Area Sources. Office of Air Quality Planning
and Standards, Research Triangle Park, NC. AP-42.
U.S. EPA (Environmental Protection Agency). 1985b. Rapid Assessment of Exposures to
Particulate Emissions from Surface Contamination Sites. Office of Health and
Environmental Assessment, Washington, DC.
U.S. EPA (Environmental Protection Agency). 1987. 1986 National Survey of Hazardous
Waste Treatment, Storage, Disposal, and Recycling Facilities (TSDR) Database.
U.S. EPA (Environmental Protection Agency). 1988. Control of Open Fugitive Dust Sources.
Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-450/3-
88-008.
U.S. EPA (Environmental Protection Agency). 1991. Hazardous Waste TSDF - Background
Information for Proposed Air Emissions Standards. Appendix C. EPA-450/3-89-023a.
Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina.
p. C-19 through C-30.
U.S. EPA (Environmental Protection Agency). 1994a. Guidance Manual for the Integrated
Exposure Uptake Biokinetic Model for Lead in Children. Office of Emergency and
Remedial Response, Washington, DC. EPA/540/R-93/081 NTIS PB93-963510
U.S. EPA (Environmental Protection Agency). 1994b. Risk Assessment Issue Paper: Status of
Inhalation Cancer Unit Risk for Benzo(a)pyrene. National Center for Environmental
Assessment. Superfund Technical Support Center, Cincinnati, OH.
U.S. EPA (Environmental Protection Agency). 1995. User's Guide for the Industrial Source
Complex (ISC3) Dispersion Models. EPA-454/B-95-003a. Office of Air Quality
Planning and Standards, Research Triangle Park, NC.
U.S. EPA (Environmental Protection Agency). 1996. Risk Assessment Issue Paper for:
Derivation of a Chronic RfCfor 1,1,1-Trichloroethane (CASRN 71-55-6). 96-007d/8-
09-96. National Center for Environmental Assessment. Superfund Technical Support
Center, Cincinnati, OH.
U.S. EPA (Environmental Protection Agency). 1997a. Health Effects Assessment Summary
Tables (HEAST). EPA-540-R-97-036. FY 1997 Update. Office of Solid Waste and
Emergency Response, Washington, DC.
6-2
-------
Volume I Section 6.0
U.S. EPA (Environmental Protection Agency). 1997b. National Advisory Committee for Acute
Exposure Guideline Levels for Hazardous Substances; Notices. 62 FR 58839-58851.
October 30.
U.S. EPA (Environmental Protection Agency). 1997c. Exposure Factors Handbook, Volume I,
General Factors. Office of Research and Development, Washington, DC. August.
EPA/600/P-95/002Fa.
U.S. EPA (Environmental Protection Agency). 1997d. Exposure Factors Handbook, Volume III,
Activity Factors. Office of Research and Development, Washington, DC. August.
EPA/600/P-95/002Fc.
U.S. EPA (Environmental Protection Agency). 1998. Hazardous waste management system;
identification and listing of hazardous waste; solvents; final rule. Federal Register 63 FR
64371-402. November 19, 1998.
U.S. EPA (Environmental Protection Agency). 1999. Integrated Risk Information System (IRIS)
- online. Duluth, MN. http://www.epa.gov/iris/
U.S. EPA (Environmental Protection Agency), (no date available). Risk Assessment Issue Paper
for: Carcinogenicity Information for Trichloroethylene (TCE)(CASRN 79-01-6).
National Center for Environmental Assessment, Superfund Technical Support Center,
Cincinnati, OH.
6-3
-------
Appendix A
Comparison with LDR Universal Treatment
Standards and Toxicity Characteristic
-------
Volume I
Appendix A
Table A-l. Comparison of LDR Universal Treatment Standards with Chronic Waste
Concentrations for Land-Based Units
UTS Level
( N o n wastewate r)
Constituent Name (mg/kg)
Acetaldehyde
Acetone
Acetonitrile
Acrolein
Acrylamide
2E+02
4E+01
2E+01
Wastepile
Level
(mg/kg)
6E+04
b,c
1E+07
1E+05
2E+01
Landfill
Level
(mg/kg)
3E+04
b,c
1E+07
6E+04
1E+01
Land
Application
Unit Level
(mg/kg)
9E+03
1E+07
2E+04
4E+00
Acrylic acid
Acrylonitrile
Allyl chloride
Aniline
Arsenic
Barium
Benzene
8E+01
3E+01
1E+01
5E+00
8E+00
1E+01
1E+03
2E+02
6E+03
3E+05
4E+03
6E+02
1E+02
4E+04
1E+07
2E+03
2E+02
4E+01
3E+03
1E+05
5E+02
Benzidine
Benzo(a)pyrene
Beryllium
Bromodichloromethane
Bromoform (Tribromomethane)
Butadiene, 1,3-
Cadmium
Carbon disulfide
Carbon tetrachloride
Chloro-1,3-butadiene, 2- (Chloroprene)
Chlorobenzene
Chlorodibromomethane
Chloroform
Chlorophenol, 2-
Chromium VI
Cobalt
Cresols (total)
Cumene
Cyclohexanol
Dibromo-3-chloropropane, 1,2-
Dichlorobenzene, 1,2-
Dichlorobenzene, 1,4-
Dichlorodifluoromethane
Dichloroethane, 1,2-
Dichloroethylene, 1,1-
Dichloropropane, 1,2-
3E+00
1E-02
2E+01
2E+01
2E-01
5E+00
6E+00
3E-01
6E+00
2E+01
6E+00
6E+00
9E-01
6E+00
2E+01
6E+00
6E+00
7E+00
6E+00
6E+00
2E+01
1E+04
5E+03
6E+05
1E+01
1E+04
1E+05
1E+03
2E+03
3E+04
1E+04
9E+02
2E+03
5E+03
2E+05
1E+02
9E+05
1E+07
1E+07
2E+04
1E+03
2E+02
2E+03
8E+04
3E+03
2E+05
9E+00
1E+05
9E+04
9E+02
1E+03
1E+04
5E+03
8E+02
2E+04
3E+04
5E+04
5E+01
4E+05
4E+05
1E+07
2E+04
1E+03
2E+02
2E+03
5E+03
4E+02
3E+04
4E+00
7E+03
3E+04
2E+02
3E+02
2E+03
7E+02
1E+02
1E+03
3E+03
7E+04
2E+01
1E+05
2E+05
7E+05
7E+03
1E+02
5E+01
2E+02
(continued)
A-l
-------
Volume I
Appendix A
Table A-l. (continued)
Constituent Name
Dichloropropene, cis-1,3-
Dichloropropene, trans-1,3-
UTS Level
(Nonwastewater)
(mg/kg)
2E+01
2E+01
Wastepile
Level
(mg/kg)
2E+03
3E+03
Landfill
Level
(mg/kg)
1E+03
1E+03
Land
Application
Unit Level
(mg/kg)
3E+02
3E+02
Dimethylbenz(a)anthracene, 7,12-
Dimethylphenol, 3,4-
Dinitrotoluene, 2,4-
Dioxane, 1,4-
1E+02
2E+02
b,c
1E+07
b,c
1E+07
4E+05
Diphenylhydrazine, 1,2-
Epichlorohydrin
Epoxybutane, 1,2-
Ethoxyethanol acetate (R-R), 2-
Ethoxyethanol, 2-
Ethylbenzene
Ethylene Dibromide
1E+01
2E+01
1E+05
2E+04
b,c
1E+07
b,c
1E+07
1E+07
1E+03
8E+04
1E+04
b,c
1E+07
b,c
1E+07
7E+05
4E+02
2E+04
4E+03
3E+05
8E+05
1E+05
6E+01
Ethylene glycol
Ethylene oxide
Formaldehyde
Furfural
Hexachloro-1 ,3-butadiene
Hexachlorobenzene
Hexachlorocyclopentadiene
Hexachloroethane
6E+00
1E+01
2E+00
3E+01
6E+02
7E+04
3E+05
1E+07
4E+02
4E+04
3E+05
3E+05
1E+02
1E+04
1E+04
2E+04
Isophorone
Lead
Manganese
Mercury
Methanol
Methoxyethanol acetate (R-R), 2-
Methoxyethanol, 2-
Methyl bromide (Bromomethane)
Methyl chloride (Chloromethane)
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
Methyl tert-butyl ether
Methylcholanthrene, 3-
Methylene chloride
4E-01
3E-01
8E-01
2E+01
3E+01
4E+01
3E+01
2E+02
2E+01
3E+01
9E+05
3E+04
1E+03
b,c
1E+07
2E+05
4E+05 a'C
1E+03
4E+03
1E+07
2E+05
1E+07
1E+07
5E+04
1E+07
1E+05
1E+03
b,c
1E+07
1E+05
2E+05
8E+02
4E+03
1E+07
9E+04
6E+05
1E+07
3E+04
5E+05
1E+04
5E+01
1E+07
4E+04
5E+04
3E+02
1E+03
6E+05
5E+04
2E+05
3E+05
8E+03
N,N-Dimethylformamide
Naphthalene
n-Hexane
6E+00
4E+04
2E+05
1E+04
1E+05
8E+03
2E+04
(continued)
A-2
-------
Volume I
Appendix A
Table A-l. (continued)
Constituent Name
Nickel
Nitrobenzene
Nitropropane, 2-
Nitrosodiethylamine
Nitrosodi-n-butylamine
N-Nitrosopyrrolidine
Phenol
Phthalic anhydride
Propylene oxide
Pyridine
Styrene
TCDD, 2,3,7,8-
Tetrachloroethane, 1,1,1,2-
Tetrachloroethane, 1,1,2,2-
Tetrachloroethylene
Toluene
UTS Level
(Nonwastewater)
(mg/kg)
5E+00
1E+01
3E+01
2E+01
4E+01
6E+00
3E+01
2E+01
1E-03
6E+00
6E+00
6E+00
1E+01
Wastepile
Level
(mg/kg)
1E+05
4E+01
7E+00
1E+02
6E+03
2E+04
7E+04
1E+07
1E+04
6E+03
4E+04
4E+05
Landfill
Level
(mg/kg)
8E+05
2E+01
6E+00
5E+01
6E+03
1E+04
2E+04
9E+05
7E+03
2E+03
3E+04
2E+05
Land
Application
Unit Level
(mg/kg)
5E+04
3E+00
8E-01
1E+01
6E+02
4E+03
1E+04
9E+05
1E+03
4E+02
5E+03
4E+04
Toluidine, o-
Trichloro-1 ,2,2-trifluoroethane, 1,1,2-
Trichlorobenzene, 1,2,4-
Trichloroethane, 1,1,1-
Trichloroethane, 1,1,2-
Trichloroethylene
Trichlorofluoromethane
Triethylamine
Vanadium
Vinyl acetate
Vinyl chloride
Xylenes (total)
3E+01
2E+01
6E+00
6E+00
6E+00
3E+01
2E-01
6E+00
3E+01
1E+07
4E+05
3E+03
2E+04
1E+05
1E+04
4E+04
2E+05
7E+01
7E+05
1E+07
2E+05
3E+03
1E+04
9E+04
8E+03
2E+05
8E+04
7E+01
3E+05
1E+07
5E+04
2E+02
2E+03
3E+04
7E+02
2E+04
4E+04
2E+01
6E+04
a Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component exceeds 1 e-5 or
HQ = 1. See text for more details.
b Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component less than 1e-5 or
HQ = 1. See text for more details.
c Organic phase emissions greater than aqueous phase emissions, so result based on organic phase would be lower.
See text &v. Ill for more details.
A-3
-------
Volume I
Appendix A
Table A-2. Comparison of Toxicity Characteristic Levels with Chronic Waste
Concentrations for Land-Based Units
Constituent Name
Acetaldehyde
Acetone
Acetonitrile
Acrolein
TC Solids
Level
(mg/kg)
Wastepile
Level
(mg/kg)
6E+04
b,c
1E+07
1E+05
2E+01
Landfill
Level
(mg/kg)
3E+04
b,c
1E+07
6E+04
1E+01
Land
Application
Unit Level
(mg/kg)
9E+03
b,c
1E+07
2E+04
4E+00
Acrylamide
Acrylic acid
Acrylonitrile
Allyl chloride
1E+03
2E+02
6E+02
1E+02
2E+02
4E+01
Aniline
Arsenic
Barium
Benzene
2E+02
2E+03
5E+01
6E+03
3E+05
4E+03
4E+04
1E+07
2E+03
3E+03
1E+05
5E+02
Benzidine
Benzo(a)pyrene
Beryllium
Bromodichloromethane
Bromoform (Tribromomethane)
Butadiene, 1,3-
Cadmium
Carbon disulfide
Carbon tetrachloride
Chloro-1,3-butadiene, 2- (Chloroprene)
Chlorobenzene
Chlorodibromomethane
Chloroform
8E+01
3E+05
1E+04
5E+03
6E+05
1E+01
1E+04
1E+05
1E+03
2E+03
3E+04
1E+04
9E+02
8E+04
3E+03
2E+05
9E+00
1E+05
9E+04
9E+02
1E+03
1E+04
5E+03
8E+02
5E+03
4E+02
3E+04
4E+00
7E+03
3E+04
2E+02
3E+02
2E+03
7E+02
1E+02
Chlorophenol, 2-
Chromium VI
Cobalt
Cresols (total)
Cumene
Cyclohexanol
Dibromo-3-chloropropane, 1,2-
Dichlorobenzene, 1,2-
Dichlorobenzene, 1,4-
Dichlorodifluoromethane
Dichloroethane, 1,2-
Dichloroethylene, 1,1-
Dichloropropane, 1,2-
Dichloropropene, cis-1,3-
1E+03
7E+04
2E+04
2E+01
7E+01
2E+03
5E+03
2E+05
1E+02
9E+05
1E+07
1E+07
2E+04
1E+03
2E+02
2E+03
2E+03
2E+04
3E+04
5E+04
5E+01
4E+05
4E+05
1E+07
2E+04
1E+03
2E+02
2E+03
1E+03
1E+03
3E+03
7E+04
2E+01
1E+05
2E+05
7E+05
7E+03
1E+02
5E+01
2E+02
3E+02
(continued)
A-4
-------
Volume I
Appendix A
Constituent Name
Dichloropropene, trans-1,3-
Table A-2.
TC Solids
Level
(mg/kg)
(continued)
Wastepile
Level
(mg/kg)
3E+03
Landfill
Level
(mg/kg)
1E+03
Land
Application
Unit Level
(mg/kg)
3E+02
Dimethylbenz(a)anthracene, 7,12-
Dimethylphenol, 3,4-
Dinitrotoluene, 2,4-
Dioxane, 1,4-
8E+00
b,c
1E+07
b,c
1E+07
4E+05 a'C
Diphenylhydrazine, 1,2-
Epichlorohydrin
Epoxybutane, 1,2-
Ethoxyethanol acetate (R-R), 2-
Ethoxyethanol, 2-
Ethylbenzene
Ethylene Dibromide
1E+05
2E+04
b,c
1E+07
1E+07°'C
1E+07
1E+03
8E+04
1E+04
b,c
1E+07
1E+07°'C
7E+05
4E+02
2E+04
4E+03
3E+05 a'C
8E+05 a'C
1E+05
6E+01
Ethylene glycol
Ethylene oxide
Formaldehyde
Furfural
Hexachloro-1 ,3-butadiene
Hexachlorobenzene
9E+03
7E+03
6E+02
7E+04
3E+05
4E+02
4E+04
3E+05
1E+02
1E+04
1E+04
Hexachlorocyclopentadiene
Hexachloroethane
5E+03
1E+07
3E+05
2E+04
Isophorone
Lead
Manganese
Mercury
Methanol
Methoxyethanol acetate (R-R), 2-
Methoxyethanol, 2-
Methyl bromide (Bromomethane)
Methyl chloride (Chloromethane)
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
Methyl tert-butyl ether
2E+03
4E+00
2E+04
9E+05
3E+04
1E+03
b,c
1E+07
2E+05
4E+05 a'C
1E+03
4E+03
1E+07
2E+05
1E+07
1E+07
1E+07
1E+05
1E+03
b,c
1E+07
1E+05
2E+05
8E+02
4E+03
1E+07
9E+04
6E+05
1E+07
5E+05
1E+04
5E+01
b,c
1E+07
4E+04
5E+04
3E+02
1E+03
6E+05
5E+04
2E+05
3E+05
Methylcholanthrene, 3-
Methylene chloride
5E+04
3E+04
8E+03
N,N-Dimethylformamide
Naphthalene
n-Hexane
Nickel
Nitrobenzene
4E+02
4E+04
2E+05
1E+05
-
1E+04
1E+05
8E+05
-
8E+03
2E+04
5E+04
-
(continued)
A-5
-------
Volume I
Appendix A
Table A-2. (continued)
Constituent Name
Nitropropane, 2-
Nitrosodiethylamine
Nitrosodi-n-butylamine
N-Nitrosopyrrolidine
TC Solids Wastepile
Level Level
(mg/kg) (mg/kg)
4E+01
7E+00
1E+02
6E+03
Landfill
Level
(mg/kg)
2E+01
6E+00
5E+01
6E+03
Land
Application
Unit Level
(mg/kg)
3E+00
8E-01
1E+01
6E+02
Phenol
Phthalic anhydride
Propylene oxide
Pyridine
Styrene
2E+04
3E+02 7E+04
1E+07
1E+04
2E+04
9E+05
4E+03
1E+04
9E+05
TCDD, 2,3,7,8-
Tetrachloroethane, 1,1,1,2-
Tetrachloroethane, 1,1,2,2-
Tetrachloroethylene
Toluene
1E+04
6E+03
3E+02 4E+04
4E+05
7E+03
2E+03
3E+04
2E+05
1E+03
4E+02
5E+03
4E+04
Toluidine, o-
Trichloro-1 ,2,2-trifluoroethane, 1,1,2-
1E+07
1E+07
1E+07D
Trichlorobenzene, 1,2,4-
Trichloroethane, 1,1,1-
Trichloroethane, 1,1,2-
Trichloroethylene
Trichlorofluoromethane
Triethylamine
Vanadium
Vinyl acetate
Vinyl chloride
Xylenes (total)
4E+05
3E+03
7E+01 2E+04
1E+05
1E+04
4E+04
2E+05
1E+01 7E+01
7E+05
2E+05
3E+03
1E+04
9E+04
8E+03
2E+05
8E+04
7E+01
3E+05
5E+04
2E+02
2E+03
3E+04
7E+02
2E+04
4E+04
2E+01
6E+04
a Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component exceeds 1 e-5 or
HQ = 1. See text for more details.
b Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component less than 1e-5 or
HQ = 1. See text for more details.
c Organic phase emissions greater than aqueous phase emissions, so result based on organic phase would be
lower. See text & v. Ill for more details.
A-6
-------
Volume I
Appendix A
Table A-3. Comparison of LDR Universal Treatment Standards (UTS) with Acute and
Subchronic Waste Concentrations for Land Application Units and Wastepiles
UTS Level
(Nonwastewater)
Constituent (mg/kg)
Acetaldehyde
Acetone
Acetonitrile
Acrolein
Acrylamide
2E+02
4E+01
-
2E+01
Land Application
Unit Level
(mg/kg)
7E+03
3E+05 a'°
3E+03
2E-01
-
Scenario
Subchronic
Acute
Subchronic
Acute
-
Wastepile
Level
(mg/kg)
5E+03
2E+05
3E+03
2E-01
-
Scenario
Subchronic
Acute
Subchronic
Acute
-
Acrylic acid
Acrylonitrile
Allyl chloride
Aniline
Arsenic
Barium
Benzene
8E+01
3E+01
1E+01
5E+00
8E+00
1E+01
5E+02
1E+02
-
8E+03
3E+05
2E+02
Acute
Subchronic
-
Acute
Subchronic
Acute
4E+02
6E+01
-
3E+03
2E+05
1E+02
Acute
Subchronic
-
Acute
Subchronic
Acute
Benzidine
Benzo(a)pyrene
Beryllium
Bromodichloromethane
Bromoform (Tribromomethane)
3E+00
1E-02
2E+01
2E+01
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Butadiene, 1 ,3-
Cadmium
Carbon disulfide
Carbon tetrachloride
Chloro-1 ,3-butadiene, 2- (Chloroprene)
Chlorobenzene
Chlorodibromomethane
Chloroform
Chlorophenol, 2-
Chromium VI
Cobalt
Cresols (total)
Cumene
Cyclohexanol
Dibromo-3-chloropropane, 1 ,2-
Dichlorobenzene, 1 ,2-
Dichlorobenzene, 1 ,4-
Dichlorodifluoromethane
Dichloroethane, 1 ,2-
Dichloroethylene, 1,1-
Dichloropropane, 1,2-
Dichloropropene, cis-1 ,3-
Dichloropropene, trans-1 ,3-
2E-01
5E+00
6E+00
3E-01
6E+00
2E+01
6E+00
6E+00
9E-01
-
6E+00
-
-
2E+01
6E+00
6E+00
7E+00
6E+00
6E+00
2E+01
2E+01
2E+01
-
9E+03
1E+03
-
4E+03
-
6E+02
-
3E+04
2E+03
-
1E+05
2E+01
5E+02
3E+05
3E+04
2E+04
1E+03
1E+03
2E+02
6E+02
7E+02
-
Subchronic
Acute
-
Subchronic
-
Acute
-
Subchronic
Subchronic
-
Subchronic
Subchronic
Subchronic
Subchronic
Acute
Subchronic
Acute
Subchronic
Subchronic
Subchronic
Subchronic
-
4E+03
9E+02
-
8E+03
-
4E+02
-
2E+04
1E+03
-
3E+04
2E+01
4E+02
2E+05
2E+04
8E+03
9E+02
6E+02
2E+02
6E+02
7E+02
-
Subchronic
Acute
-
Subchronic
-
Acute
-
Subchronic
Subchronic
-
Subchronic
Subchronic
Subchronic
Subchronic
Acute
Subchronic
Acute
Subchronic
Acute
Subchronic
Subchronic
Dimethylbenz(a)anthracene, 7,12-
(continued)
A-7
-------
Volume I
Appendix A
Table A-3. (continued)
Constituent
UTS Level
(Nonwastewater)
(mg/kg)
Land Application
Unit Level
(mg/kg)
Scenario
Wastepile
Level
(mg/kg)
Scenario
Dimethylphenol, 3,4-
Dinitrotoluene, 2,4-
Dioxane, 1,4-
1E+02
2E+02
-
1E+04
-
Acute
-
3E+04
-
Acute
Diphenylhydrazine, 1,2-
Epichlorohydrin
Epoxybutane, 1 ,2-
Ethoxyethanol acetate (R-R), 2-
Ethoxyethanol, 2-
Ethylbenzene
Ethylene Dibromide
-
-
-
1E+01
2E+01
8E+02
6E+03
4E+03
3E+04
2E+04
7E+01
Subchronic
Subchronic
Acute
Acute
Subchronic
Subchronic
8E+02
5E+03
3E+03
3E+04
3E+04
2E+02
Subchronic
Subchronic
Acute
Acute
Subchronic
Subchronic
Ethylene glycol
Ethylene oxide
Formaldehyde
Furfural
Hexachloro-1 ,3-butadiene
Hexachlorobenzene
Hexachlorocyclopentadiene
Hexachloroethane
-
-
-
6E+00
1E+01
2E+00
3E+01
7E+03
2E+03
2E+04
-
-
-
9E+05 "
Subchronic
Acute
Subchronic
-
-
-
Acute
5E+03
1E+03
1E+05
-
-
-
1 E+07 "
Subchronic
Acute
Subchronic
-
-
-
Subchronic
Isophorone
Lead
Manganese
Mercury
Methanol
4E-01
-
3E-01
8E-01
-
3E+04
8E+00
4E+05 a'°
-
Subchronic
Acute
Acute
-
2E+04
3E+01 "
2E+05
-
Subchronic
Acute
Acute
Methoxyethanol acetate (R-R), 2-
Methoxyethanol, 2-
Methyl bromide (Bromomethane)
Methyl chloride (Chloromethane)
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
Methyl tert-butyl ether
Methylcholanthrene, 3-
Methylene chloride
-
2E+01
3E+01
4E+01
3E+01
2E+02
-
2E+01
3E+01
7E+02
2E+02
7E+02
9E+04
7E+04
3E+05 "
1E+04
-
1E+04
Acute
Acute
Acute
Subchronic
Subchronic
Subchronic
Acute
-
Acute
7E+02
9E+01
3E+02
6E+04
4E+04
3E+05 "
1E+04
-
7E+03
Acute
Acute
Acute
Subchronic
Subchronic
Subchronic
Acute
-
Acute
N,N-Dimethylformamide
Naphthalene
n-Hexane
Nickel
Nitrobenzene
Nitropropane, 2-
Nitrosodiethylamine
Nitrosodi-n-butylamine
N-Nitrosopyrrolidine
6E+00
-
5E+00
1E+01
-
3E+01
2E+01
4E+01
1E+04
5E+03
1E+05
-
6E+02
-
-
-
Subchronic
Subchronic
Subchronic
-
Subchronic
-
-
-
6E+03
8E+03
7E+04
-
9E+02
-
-
-
Subchronic
Subchronic
Subchronic
-
Subchronic
-
-
-
(continued)
A-8
-------
Volume I
Appendix A
Table A-3. (continued)
UTS Level
(Nonwastewater)
Constituent (mg/kg)
Phenol
Phthalic anhydride
Propylene oxide
Pyridine
Styrene
TCDD, 2,3,7,8-
Tetrachloroethane, 1,1,1,2-
Tetrachloroethane, 1,1,2,2-
Tetrachloroethylene
Toluene
6E+00
3E+01
2E+01
-
1E-03
6E+00
6E+00
6E+00
1E+01
Land Application
Unit Level
(mg/kg)
-
2E+03
-
2E+05
-
-
1E+05
1E+03
2E+04
Scenario
-
Subchronic
-
Acute
-
-
Subchronic
Acute
Acute
Wastepile
Level
(mg/kg)
-
1E+03
-
5E+04
-
-
2E+05
1E+03
2E+04
Scenario
-
-
Subchronic
-
Acute
-
-
Subchronic
Acute
Acute
Toluidine, o-
Trichloro-1 ,2,2-trifluoroethane, 1,1,2-
Trichlorobenzene, 1,2,4-
Trichloroethane, 1,1,1-
Trichloroethane, 1,1,2-
Trichloroethylene
Trichlorofluoromethane
Triethylamine
Vanadium
Vinyl acetate
Vinyl chloride
Xylenes (total)
3E+01
2E+01
6E+00
6E+00
6E+00
3E+01
-
2E-01
6E+00
3E+01
-
-
1E+04
-
8E+03 a
9E+04
2E+03
4E+03
7E+03 a
1E+03
8E+03 a
-
-
Acute
-
Subchronic
Subchronic
Subchronic
Subchronic
Subchronic
Subchronic
Acute
-
-
8E+03
-
1E+04
5E+04
4E+03
2E+03
5E+03
3E+02
9E+03 a
-
-
Acute
-
Subchronic
Subchronic
Subchronic
Subchronic
Subchronic
Acute
Acute
a Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component exceeds 1e-5 or HQ = 1.
See text for more details.
b Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component less than 1 e-5 or HQ = 1.
See text for more details.
0 Organic phase emissions greater than aqueous phase emissions, so result based on organic phase would be lower.
See text & v. Ill for more details.
A-9
-------
Volume I
Appendix A
Table A-4. Comparison of Toxicity Characteristic Levels (TC) with Acute and Subchronic
Waste Concentrations for Land Application Units and Wastepiles
TC (Waste) Land Application
Constituent
Level
(mg/kg)
Unit Level
(mg/kg)
Scenario
Wastepile
Level
(mg/kg)
Scenario
Acetaldehyde
7E+03
Subchronic
5E+03 Subchronic
Acetone
3E+05
Acute
2E+05
Acute
Acetonitrile
3E+03
Subchronic
3E+03 Subchronic
Acrolein
2E-01
Acute
2E-01
Acute
Acrylamide
Acrylic acid
Acrylonitrile
5E+02
Acute
4E+02
Acute
Allyl chloride
1E+02
Subchronic
6E+01 Subchronic
Aniline
Arsenic
2E+02
8E+03
Acute
3E+03
Acute
Barium
2E+03
3E+05
Subchronic
2E+05 Subchronic
Benzene
5E+01
2E+02
Acute
1E+02
Acute
Benzidine
Benzo(a)pyrene
Beryllium
Bromodichloromethane
Bromoform (Tribromomethane)
Butadiene, 1,3-
Cadmium
Carbon disulfide
9E+03 Subchronic
4E+03 Subchronic
Carbon tetrachloride
8E+01
1E+03
Acute
9E+02
Acute
Chloro-1,3-butadiene, 2- (Chloroprene)
Chlorobenzene
3E+05
4E+03 Subchronic
8E+03 Subchronic
Chlorodibromomethane
Chloroform
6E+02
Acute
4E+02
Acute
Chlorophenol, 2-
Chromium VI
1E+03
3E+04
Subchronic
2E+04 Subchronic
Cobalt
2E+03
Subchronic
1E+03 Subchronic
Cresols (total)
7E+04
Cumene
1E+05
Subchronic
3E+04 Subchronic
Cyclohexanol
2E+01
Subchronic
2E+01 Subchronic
Dibromo-3-chloropropane, 1,2-
5E+02
Subchronic
4E+02 Subchronic
Dichlorobenzene, 1,2-
3E+05
Subchronic
2E+05 Subchronic
Dichlorobenzene, 1,4-
2E+04
3E+04
Acute
2E+04
Acute
Dichlorodifluoromethane
2E+04
Subchronic
8E+03 Subchronic
Dichloroethane, 1,2-
2E+01
1E+03
Acute
9E+02
Acute
Dichloroethylene, 1,1-
7E+01
1E+03
Subchronic
6E+02 Subchronic
Dichloropropane, 1,2-
2E+02
Subchronic
2E+02
Acute
Dichloropropene, cis-1,3-
6E+02
Subchronic
6E+02 Subchronic
Dichloropropene, trans-1,3-
7E+02
Subchronic
7E+02 Subchronic
(continued)
A-10
-------
Volume I
Appendix A
Table A-4. (continued)
Constituent
TC (Waste) Land Application
Level Unit Level
(mg/kg) (mg/kg)
Scenario
Wastepile
Level
(mg/kg) Scenario
Dimethylbenz(a)anthracene, 7,12-
Dimethylphenol, 3,4-
Dinitrotoluene, 2,4-
8E+00
Dioxane, 1,4-
1E+04
Acute
3E+04
Acute
Diphenylhydrazine, 1,2-
Epichlorohydrin
8E+02
Subchronic
8E+02 Subchronic
Epoxybutane, 1,2-
6E+03
Subchronic
5E+03 Subchronic
Ethoxyethanol acetate (R-R), 2-
4E+03
Acute
3E+03
Acute
Ethoxyethanol, 2-
3E+04
Acute
3E+04
Acute
Ethylbenzene
2E+04
Subchronic
3E+04 Subchronic
Ethylene Dibromide
7E+01
Subchronic
2E+02 Subchronic
Ethylene glycol
Ethylene oxide
7E+03
Subchronic
5E+03 Subchronic
Formaldehyde
2E+03
Acute
1E+03
Acute
Furfural
2E+04
Subchronic
1E+05 Subchronic
Hexachloro-1,3-butadiene
9E+03
Hexachlorobenzene
7E+03
Hexachlorocyclopentadiene
Hexachloroethane
5E+03
9E+05
Acute
1E+07 Subchronic
Isophorone
Lead
2E+03
Manganese
3E+04
Subchronic
2E+04 Subchronic
Mercury
4E+00
8E+00
Acute
3E+01
Acute
Methanol
4E+05
Acute
2E+05
Acute
Methoxyethanol acetate (R-R), 2-
Methoxyethanol, 2-
7E+02
Acute
7E+02
Acute
Methyl bromide (Bromomethane)
2E+02
Acute
9E+01
Acute
Methyl chloride (Chloromethane)
7E+02
Acute
3E+02
Acute
Methyl ethyl ketone
2E+04
9E+04
Subchronic
6E+04 Subchronic
Methyl isobutyl ketone
7E+04
Subchronic
4E+04 Subchronic
Methyl methacrylate
3E+05
Subchronic
3E+05 Subchronic
Methyl tert-butyl ether
1E+04
Acute
1E+04
Acute
Methylcholanthrene, 3-
Methylene chloride
1E+04
Acute
7E+03
Acute
N,N-Dimethylformamide
Naphthalene
1E+04
Subchronic
6E+03 Subchronic
n-Hexane
5E+03
Subchronic
8E+03 Subchronic
Nickel
1E+05
Subchronic
7E+04 Subchronic
Nitrobenzene
4E+02
Nitropropane, 2-
6E+02
Subchronic
9E+02 Subchronic
Nitrosodiethylamine
(continued)
A-ll
-------
Volume I
Appendix A
Table A-4. (continued)
Constituent
TC (Waste) Land Application
Level Unit Level
(mg/kg) (mg/kg)
Scenario
Wastepile
Level
(mg/kg) Scenario
Nitrosodi-n-butylamine
N-Nitrosopyrrolidine
Phenol
Phthalic anhydride
Propylene oxide
2E+03 Subchronic
1E+03 Subchronic
Pyridine
3E+02
Styrene
2E+05 Acute
5E+04 Acute
TCDD, 2,3,7,8-
Tetrachloroethane, 1,1,1,2-
Tetrachloroethane, 1,1,2,2-
1E+05 Subchronic
2E+05 Subchronic
Tetrachloroethylene
3E+02
1E+03
Acute
1E+03
Acute
Toluene
2E+04
Acute
2E+04
Acute
Toluidine, o-
Trichloro-1,2,2-trifluoroethane, 1,1,2-
Trichlorobenzene, 1,2,4-
Trichloroethane, 1,1,1-
1E+04
Acute
8E+03
Acute
Trichloroethane, 1,1,2-
Trichloroethylene
7E+01
8E+03
Subchronic
1E+04 Subchronic
Trichlorofluoromethane
9E+04
Subchronic
5E+04 Subchronic
Triethylamine
2E+03
Subchronic
4E+03 Subchronic
Vanadium
4E+03
Subchronic
2E+03 Subchronic
Vinyl acetate
7E+03
Subchronic
5E+03 Subchronic
Vinyl chloride
1E+01
1E+03
Subchronic
3E+02
Acute
Xylenes (total)
8E+03
Acute
9E+03
Acute
a Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component
exceeds 1 e-5 or HQ = 1. See text for more details.
b Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component less than
1 e-5 or HQ = 1. See text for more details.
c Organic phase emissions greater than aqueous phase emissions, so result based on organic phase would be lower.
See text &v. Ill for more details.
A-12
-------
Volume I
Appendix A
Table A-5. Comparison of Toxicity Characteristic Levels with
Chronic Waste Concentrations for Tanks
TC (Leachate)
Constituent Name (mg/L)
Acetaldehyde
Acetone
Acetonitrile
Acrolein
Acrylamide
Acrylic acid
Acrylonitrile
Allyl chloride
Aniline
Aerated Nonaerated
Treatment Treatment
Tank Level Tank Level
(mg/L) (mg/L)
4E+02
1E+07
2E+03
3E-01
4E+04
5E+03
1E+01
4E+00
6E+02
4E+02
8E+05
1E+03
3E-01
3E+04
3E+03
1E+01
5E+00
4E+02
Storage
Tank
Level
(mg/L)
5E+03
1E+07D
2E+04
4E+00
2E+05
3E+04
2E+02
2E+02
3E+03
Arsenic 5E+00
Barium 1E+02
Benzene 5E-01
Benzidine
Benzo(a)pyrene
3E+01
5E+04
1E+03
4E+01
3E+04
8E+02
1E+03
2E+05
6E+03
Beryllium
Bromodichloromethane
Bromoform (Tribromomethane)
Butadiene, 1,3-
2E+01
6E+02
4E-01
2E+01
7E+02
4E-01
6E+02
1E+04
2E+01
Cadmium
Carbon disulfide
Carbon tetrachloride 5E-01
Chloro-1,3-butadiene, 2- (Chloroprene)
Chlorobenzene 1E+02
Chlorodibromomethane
Chloroform
Chlorophenol, 2-
3E+03
1E+01
3E+01
1E+02
2E+01
1E+01
2E+01
3E+03
2E+01
4E+01
1E+02
3E+01
1E+01
2E+01
1E+05
7E+02
1E+03
5E+03
4E+02
4E+02
3E+02
Chromium VI 5E+00
Cobalt
Cresols (total) 2E+02
Cumene
Cyclohexanol
Dibromo-3-chloropropane, 1,2-
Dichlorobenzene, 1,2-
Dichlorobenzene, 1,4- 8E+00
Dichlorodifluoromethane
Dichloroethane, 1,2- 5E-01
Dichloroethylene, 1,1- 7E-01
Dichloropropane, 1,2-
3E+02
2E+03
4E+00
2E+03
1E+03
5E+03
8E+02
1E+01
4E+00
2E+01
2E+02
2E+03
3E+00
2E+03
2E+03
8E+03
1E+03
2E+01
5E+00
3E+01
1E+03
1E+05
3E+01
2E+04
5E+04
2E+05
5E+04
4E+02
2E+02
9E+02
(continued)
A-13
-------
Volume I
Appendix A
Table A-5. (continued)
Constituent Name
Dichloropropene, cis-1,3-
Dichloropropene, trans-1,3-
Dimethylbenz(a)anthracene, 7,12-
Aerated
Treatment
TC (Leachate) Tank Level
(mg/L) (mg/L)
8E+00
1E+01
4E+03
Nonaerated
Treatment
Tank Level
(mg/L)
1E+01
1E+01
3E+03
Storage
Tank
Level
(mg/L)
3E+02
3E+02
2E+04
Dimethylphenol, 3,4-
Dinitrotoluene, 2,4-
Dioxane, 1,4-
Diphenylhydrazine, 1,2-
Epichlorohydrin
Epoxybutane, 1,2-
Ethoxyethanol acetate (R-R), 2-
Ethoxyethanol, 2-
Ethylbenzene
Ethylene Dibromide
Ethylene glycol
Ethylene oxide
Formaldehyde
Furfural
Hexachloro-1 ,3-butadiene
Hexachlorobenzene
Hexachlorocyclopentadiene
Hexachloroethane
Isophorone
Lead
1E-01 2E+03
9E+04
5E+02
2E+03
1E+02
7E+04
4E+05
5E+03
2E+00
1E+07
8E+00
4E+03
1E+04
5E-01 2E+01
1E-01 5E+00
7E-01
3E+00 2E+02
2E+03
5E+00
1E+03
5E+04
4E+02
2E+03
2E+02
5E+04
3E+05
7E+03
3E+00
1E+07
7E+00
3E+03
1E+04
4E+01
2E+01
2E+00
3E+02
1E+03
7E+03
6E+05
3E+03
1E+04
4E+03
4E+05
1E+07D
3E+05
5E+01
1E+07
1E+02
2E+04
9E+04
1E+03
2E+02
7E+01
5E+03
1E+04
Manganese
Mercury
Methanol
Methoxyethanol acetate (R-R), 2-
Methoxyethanol, 2-
Methyl bromide (Bromomethane)
Methyl chloride (Chloromethane)
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
Methyl tert-butyl ether
Methylcholanthrene, 3-
Methylene chloride
N,N-Dimethylformamide
Naphthalene
n-Hexane
2E-01 2E+00
1E+07
9E+03
3E+04
2E+01
1E+02
2E+02 3E+04
1E+03
7E+03
2E+04
1E+03
5E+02
1E+05
3E+01
1E+03
3E+00
1E+07
6E+03
2E+04
3E+01
2E+02
2E+04
2E+03
1E+04
3E+04
9E+02
7E+02
8E+04
5E+01
1E+03
1E+02
1E+07
5E+04
2E+05
9E+02
7E+03
3E+05
2E+04
2E+05
6E+05
6E+03
2E+04
6E+05
8E+02
6E+04
(continued)
A-14
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Volume I
Appendix A
Table A-5. (continued)
Constituent Name
Aerated
Treatment
TC (Leachate) Tank Level
(mg/L) (mg/L)
Nonaerated
Treatment
Tank Level
(mg/L)
Storage
Tank
Level
(mg/L)
Nickel
Nitrobenzene
Nitropropane, 2-
Nitrosodiethylamine
Nitrosodi-n-butylamine
N-Nitrosopyrrolidine
Phenol
Phthalic anhydride
Propylene oxide
Pyridine
Styrene
TCDD, 2,3,7,8-
Tetrachloroethane, 1,1,1,2-
Tetrachloroethane, 1,1,2,2-
Tetrachloroethylene
Toluene
Toluidine, o-
Trichloro-1 ,2,2-trifluoroethane, 1,1,2-
Trichlorobenzene, 1,2,4-
Trichloroethane, 1,1,1-
Trichloroethane, 1,1,2-
Trichloroethylene
Trichlorofluoromethane
Triethylamine
2E+00 1E+02
4E-01
2E-01
3E-01
3E+03
1E+04
1E+07
3E+02
5E+00 7E+02
6E+03
5E-03
4E+01
1E+01
7E-01 4E+02
2E+03
3E+02
1E+05
2E+03
4E+03
2E+01
5E-01 1E+02
3E+03
1E+02
1E+02
4E-01
1E-01
4E-01
2E+03
1E+04
1E+07
3E+02
5E+02
8E+03
6E-03
6E+01
1E+01
5E+02
2E+03
2E+02
2E+05
3E+03
5E+03
3E+01
2E+02
3E+03
1E+02
1E+03
4E+00
1E+00
7E+00
1E+04
9E+04
1E+07
3E+03
5E+03
2E+05
4E-02
2E+03
2E+02
2E+04
9E+04
2E+03
1E+07
6E+04
2E+05
7E+02
6E+03
1E+05
2E+03
Vanadium
Vinyl acetate
Vinyl chloride
Xylenes (total)
2E+03
2E-01 2E+00
2E+03
2E+03
3E+00
b b
3E+03
4E+04
1E+02
9E+04
a Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component exceeds
1 e-5 or HQ = 1. See text for more details.
b Aqueous-phase result exceeds solubility or Csat. Risk for pure, organic-phase component less than
1 e-5 or HQ = 1. See text for more details.
c Organic phase emissions greater than aqueous phase emissions, so result based on organic phase
would be lower. See text & v. Ill for more details.
A-15
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