EPA/530-SW-87-002B
Technical Resource Document for Obtaining
Variances from the Secondary Containment
Requirement of Hazardous Waste Tank Systems
Volume 2: Risk-Based Variance
Prepared by:
Office of Solid Waste
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
February 1987
US Er.vironmental Protection Agency
R^J Jn V, LUsrary'
230 Soutih Dearborn Street "
ttlinms 0604
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DISCLAIMER
This report was prepared under contract to an agency of the United States
Government. Neither the United States Government nor any of its .
employees, contractors, subcontractors, or the.ir employees makes any
warranty, expressed or implied, or assumes any legal liability or
responsibility for any third party's use of or the results of such use of
any information, apparatus, product, or process disclosed in this report,
or represents that its use by such third party would not infringe on
privately owned rights.
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OSWER Directive 9483.00-2
TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY
1. INTRODUCTION ;. : 1-1
1.1 Overview of the Risk-Based Variance Application Process .. 1-6
1.2 Relationship to Other'Rules, Policies, and Guidelines .... 1-3
1.2.1 Ground-Water Protection Strategy (GWPS) 1.-8
1.2.2 Location Standards (Hydrogeologic Vulnerability
Criteria) 1-10
1.2.3 Alternate Concentration Limit (ACL) Guidance 1-11
1.2,4 Superfund Exposure Assessment and Public Health
Evaluation Manuals 1-12
1.2.5 EPA Guidelines for Health Risk Assessments 1-15
1.3 Initiating the Variance Application 1-17
1.4 Organization of Technical Resource Document: Volume II .. 1-20
2. SOURCE CHARACTERIZATION 2-1
2.1 Physical, Chemical and Toxicological Characteristics
of Constituents 2-1
2.1.1 Physical and Chemical Properties 2-1
2.1.2 Toxicological Properties 2-10
2.2 Selection of Indicator Chemicals 2-13
2.2.1 Identification of Representative Chemical
Concentrations 2-15
2.2.2 Calculation of Indicator Scores for all
Chemicals 2-18
2.2.3 Selection of Final Indicator Chemicals 2-19
2.3 Potential Worst-Case Release Volumes and Indicator
Chemical Release Masses 2-27
2.3.1 Determination of Worst-Case Potential Release
Volumes 2-27
2.3.2 Calculation of Indicator Chemical Release Masses. . 2-30
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(iv)
TABLE OF CONTENTS (continued)
3. HYDROGEOLOGIC CHARACTERIZATION ............. ............ ........ 3-1
3. I Investigative Techniques ................................. 3-4
3.2 Climatic Characteristics ................................. 3-7 .
3.3 Regional and Site Geology ..... . .......... ......... , ..... 3-10
3.3.1 Surficial Geology .............................. ... 3-10
3.3.2 Subsurface Geology ............................ ... 3-12
3.4 Unsaturated Zone Characterization ........................ 3-15
3.5 Saturated Zone Characterization .......................... 3-18
3.5.1 Aquifer Characteristics .......................... 3-20
3.5.2 Ground-Water Flow Characteristics ................ 3-26
3 .6 Surface Water Considerations ..................... . ....... 3-31
4. SURROUNDING LAND USE, WATER USE, AND WATER QUALITY
CHARACTERISTICS ............................................... 4-L
4.1 Ground-Water Use and Quality Characteristics
4.1.1 Proximity and Withdrawal Rates of Ground-Water
Users 4-3
4.1.2 Existing Quantity of Ground Water 4-4
4.1.3 Existing Quality of Ground Water 4-7
4.1.4 Future Uses of Ground Water 4-7 ,
4.2 Surface Water Use and Quality Characteristics 4-14
4.2.1 Existing Quality of Surface Water 4-15
4.2.2 Current Uses of Surface Water .............'....... 4-17
4.2.3 Future Uses of Surface Water 4-17
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OSWER Directive 9483.00-2
(V)
TABLE OF CONTENTS (continued)
Page
4.3 Current and Future Uses of Surrounding Land . .- 4-19'
5. IDENTIFYING EXPOSURE PATHWAYS AND ESTIMATING EXPOSURE POINT
CONCENTRATIONS ". 5-1
5.1 Identify Exposure Pathways 5-2
5.1.1 Determine Possible Chemical Release Sources,
Transport Mechanisms, and Transport Media 5-6
5.1.2 Identify and Characterize Exposure Points
and Routes 5-6
5.1.3 Integrate Release Sources, Transport Mechanisms
and Media, and Exposure Points and Routes into
Exposure Pathways i 5-14
5.1.4 Determine Presence of Sensitive Populations and
Environmental Receptors 5-14
5.2 Estimate Exposure Point Concentrations 5-15
5.2.1 Surface Water Transport Modeling 5-19
5.2.2 Ground-Water Transport Modeling 5 - L9
5.2.3 Air Transport Modeling 5-23
6. HEALTH EFFECTS EVALUATION
6.1 Compare Exposure Point Concentrations to Established
Quality Standards 6-1
6.1.1 National Primary Drinking Water Standards/
Maximum Contaminant Levels (MCLs) 6-6
6.1.2 MCL Goals (MCLGs) 6-7
6.1.3 Federally-Approved State Water Quality
Standards 6-7
6.1.4 Federal Ambient Water Quality Criteria (WQC) 6-8
6.1.5 National Ambient Air Quality Standards (NAAQSs) .. 6-9
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(vl)
TABLE OF CONTENTS (continued)
Page
6.1.6 Drinking Wacer Health Advisories (DWHA's) 6-9
6.2 Estimate Chemical Intakes -. . . 6-10
6.2.1 Calculate Ground-Water Intakes 6-12
6.2.2 Calculate Surface Water Intakes . . 6-12
6.2.3 Calculate Air Intakes 6-17
6.2.4 Calculate Intakes From Other Exposure Pathways ... 6-22
6.2.5 Combine Pathway-Specific Intakes to Yield Total
Oral and Total Inhalation Intakes 6-22
6.3 Determine Chemical Toxicities 6-29
6.4 Risk Characterization 6-32
6.4. 1 Noncarcinogenic Effects 6-32
6.4.2 Carcinogenic Effects 6-37
6.4.3 Other Considerations 6-37
ENVIRONMENTAL IMPACT EVALUATION 7-1
7.1 Compare Exposure Point Concentrations and
Quality Standards 7-4
7.2 Derivation of Site-Specific Criteria 7-10
7.2.1 Derivation of Aquatic Criteria 7-10
7.2.2 Derivation of Terrestrial Criteria 7-15
7.3 Site-Specific Exposure Point Evaluation 7-16
8. SUMMARIZING THE RISK-BASED VARIANCE APPLICATION 8-1
8.1 Summarize the Source, Surrounding Area, and
Exposure Characteristics 8-1
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(vii)
TABLE OF CONTENTS (continued)
. Page
8.2 Summarize the Health Effects Evaluation ,' 8-4
3.3 Summarize the Environmental Impact Assessment 3-6
3.4 Conclude and Submit the Risk-Based Variance
Application 8-6
t
REFERENCES
APPENDICES
APPE.N'DIX A: Preliminary Screening for Risk-Based Variance
APPENDIX B: Information Sources for Environmental and
Hydrogeologic Information
APPENDIX C: Tables of Chemical-Specific Data
APPENDIX D: Detailed Procedures for Determining Toxicity
Constants for Indicator Chemical Selection
APPENDIX E: Blank Worksheets
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(viii)
LIST OF EXHIBITS
l-l.
2-1.
2-2.
2-3.
2-4.
2-5.
3-1.
3-2.
3-3.
3-4.
4-1.
5-1.
5-2.
5-3.
5-4.
5-5.
6-1.
6-2.
Plan View of Hypothetical Facility
Overview of Source Characterization
Transport of Contaminants with Different Specific
Gravities
Overview of Procedure for Selecting Indicator Chemicals
Hypothetical Release Volume Profiles
Hypothetical Release Mass Profile for Benzene
Overview of Process to Characterize Sice Hydrogeology . .
Hydrogeologic Investigative Techniques for Subsurface
Investigations ;
Examples of Formats for Presenting Hydrogeologic
Information
Principal Sources of Geocechnical Data
Overview of Process to Characterize Surrounding
Water Use and Water Qualitv
Overview of Exposure Point Concentration Estimation ....
Illustration of Typical Exposure Pathways
Common Release Sources, Transport Mechanisms, and
Transport Media
Typical Present and Potential Exposure Pathways
Illustration of Short-Term and Long-Term Concentrations.
Overview of Health Effects Evaluation
Standard Values Used in Daily Intake Calculations
Page
1-5
2-2
2-9
2-14
2-28
2-36
3-3
3-5
3-6
3-8
4-2
3-3
5-5
5-7
5-11
5-17
6-2
6-11
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OSWER Directive 9483.00-2
LIST OF EXHIBITS (continued)
Page
6-3. Decision Tree for the Evaluation of Potential
Noncarcinogenic Effects 6-33
7-1. Overview of the Environmental Impact Evaluation 7-3
7-2. Acute and Chronic Water'Quality Criteria for Protection
of Freshwater and Marine Organisms and LOEL (Lowest
Observed Effect Level) Values 7-5
7-3. Chemical Specific Toxicity Information in the National
Acute Toxicity Data Set 7-10
3-1 Worksheets for Summarizing Che Risk-Based Variance
Application 8-2
A-l. Illustration of Typical Exposure Pathways A-24
C-l. Physical, Chemical, and Fate Data C-3
C-2. Half-Lives in Various Media C-14
C-3. Toxicity Data for Potential Carcinogenic Effects
-- Selection of Indicator Chemicals Only C-2Q
C-4. Toxicity Data for Potential Carcinogenic Effects
-- Risk Characterization C-24
C-3. Toxicicy Data for Soncarcinogenic Effects --
Selection of Indicator Chemicals Only C-28
C-6. Toxicity Data for Noncarcinogenic Effects --
Risk Characterization C-36
C-7. Chemicals and Chemical Groups Having EPA Health
Effects Assessment (HEA) Documents C-44
C-8. Safe Drinking Water Act Maximum Contaminant Levels
(MCLs) C-46
C-9. Safe Drinking Water Act Maximum Contaminant Levels
Goals (MCLGs) c-47
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(.X)
LIST OF EXHIBITS (continued)
Page
f
C-10. EPA Ambient Water Quality Criteria (VQC) for.
Protection of Human Health " C-48
C-ll. EPA Drinking Water Health Advisories and
Recommended Concentration C-52
C-12. Clean Air Act National Ambient Air Quality
Standards (NAAQS) C-33
D-l. Rating Constants (RV ) for Noncarcinogens D-3
D-2. EPA Weight-of-Evidence Categories for Potential
Carcinogens D-5
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(xi)
LIST OF WORKSHEETS
1-1. Timetable for Demonstration of Risk-Based Variance
from Secondary Containment 1-18
2-1.- Physical and Chemical Characteristics of Constituents .. 2-4
2-2. Indicator Chemical Toxicity Information 2-11
2-3. Calculation of Overall Chemical Concentrations in Tank
Systems 2-16
2-4. Scoring for Indicator Chemical Selection: Overall
Concentrations, Koc, and log Kow Values 2-17
2-5. Scoring for Indicator Chemical Selection: Calculation
of Indicator Score Values.and Tentative Rank for
Carcinogenic Effects 2-20
2-6. Scoring for Indicator Chemical Selection: Calculation
of Indicator Score Values and Tentative Rank for
Noncarcinogenic Effects 2-21
2-7. Scoring for Indicator Chemical Selection: Calculation
of Indicator Score Values and Tentative Rank for
Environmental Effects 2-22
2-3. Scoring for Indicator Chemical Selection for Human
Health Effects Evaluation: Evaluation of Exposure
Factors and Final Chemical Selection 2-23
2-9. Scoring for Indicator Chemical Selection for Environ-
mental Impact Evaluation: Evaluation of Exposure
Factors and Final Chemical Selection 2-2S
2-10. Release Volume Profiles Associated with Each Tank
System 2-31
2-11. Release Mass Profiles Associated with Each Indicator
Chemical: Minimum Concentration 2-32
2-12. Release Mass Profiles Associated with Each Indicator
Chemical: Maximum Concentration 2-33
2-13. Release Mass Profiles Associated with Each Indicator
Chemical: Representative Concentration 2-34
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(xii)
LIST OF WORKSHEETS (continued)
4-1.
4-2.
4-3.
4-4.
4-5 .
4-6.
4-7.
5-1.
5-2.
5-3.
5 -4 .
6-1.
6-2.
6-3.
6-4.
6-5.
6-6.
Proximity and Withdrawal Rates of Ground-Watar Users . . .
Measured Ground-Water Concentrations of Background
Chemicals
Comparison of Background Chemical Concentrations in
Ground Water so Drinking Water Standards and Guidelines.
Treatment Options for Reducing Contaminant Levels
Surface Water Contamination Sources
Measured Surface Water Concentrations of Background
Chemicals
Summary of Current and Future Uses of Surface Waters
in the Area
Potential Human Exposure Pathways
Potential Environmental Receptor Exposure Pathways
Contaminant Concencrations at Human Exposure Points ....
Contaminant Concentrations at Environmental Receptor
Exposure Points
Comparison of Human Exposure Point Concentrations to
Established Standards
Subchronic Ground-Water Intakes
Chronic Ground-Water Intakes
Subchronic Surface Water Intakes
Chronic Surface Water Intakes
Subchronic Fish Intakes
Page
4-5
4-8
4-10
4-11
4-16
4-18
4-20
5-3
5-9
5-20
5-21
6-5
6-13
6-14
6-15
6-16
6-18
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(xiii)
LIST OF WORKSHEETS (continued)
.Page
6-7. Chronic Fish Intakes : 6-19
6-8. Subchronic Air Intakes 6-20
6-9. Chronic Air Intakes 6-21
6-10. Other Subchronic Intakes 6-23
6-11. Other Chronic Intakes 6-24
6-12. Pathways Contributing to Total Exposure 6-26
6-13. Total Subchronic Daily Intake (SDI) 6-27
6-14. Total Chronic Daily Intake (GDI) 6-28
6-15. Critical Toxicity Values ' 6-31
6-16. Calculation of Subchronic Hazard Index for Each
Exposure Point 6-35
6-17. Calculation of Chronic Hazard Index for Each
Exposure Point 6-36
6-i3. Calculation of Potential Carcinogenic Risks for Each
Exposure Point 6-33
7-1 Comparison of Environmental Receptor Exposure Point
Concentration With Water Quality Criteria 7-5
A-l. Test for Applicability of the Secondary Containment
Requirement to the Facility A-4
A-2. Test for Applicability of the Secondary Containment
Requirement and Eligibility for a Variance for
Individual Tanks A-5
A-3. Deadlines for Providing Notice of Intent to Apply
for a Variance A-7
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OSWER Directive 9483.00-2
(xiv)
LIST OF WORKSHEETS (continued)
A-<*. Waste Constituent Concentrations and Comparison
to Standards A-12
A-5. Hydrogeologic Considerations A-15
A-6. Surrounding Water Use, Water Quality, and Land
Use Considerations .A-19
A-7. Screening of Potential Exposure Pathways A-25
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OSWER Directive 9483.00-2
EXECUTIVE SUMMARY
INTRODUCTION
On July 14,. 1986, the U.S. EPA issued regulations for tank systems
managing hazardous wastes (31 Federal Register 25422). The overall goal of
the regulations is to ensure the protection of human health and the
environment from the risks posed by releases from hazardous waste tank
systems. The regulations address, among other issues, the design and
installation of tanks, leak testing and detection, corrosion protection,
structural integrity, responses to leaks, closure and post-closure, and
secondary containment. The secondary containment requirement is a major
feature of the July 14, 1986 regulation. The requirement applies immediately
to all new tank systems (and systems to be reinstalled) and is to be phased in
for existing systems. Variances from secondary containment are the subjects
of this document (Volumes I and II).
The regulations provide two variances from the secondary containment
requirement. The owner/operator of the tank system can petition the Regional
Administrator (or, in some states, the appropriate State Official) for a
variance from the secondary containment requirement in one of the following
ways:
Technology-Based Variance (Volume I). Alternative
design or operating practices will detect, leaks and
prevent the migration of any hazardous waste beyond a
zone of engineering control (i.e., an area under the
control of the owner/operator that, upon detection of
a release, can and will be readily cleaned up prior to
the release of hazardous constituents to ground water
or surface waters).
Risk-Based Variance (Volume II). If a release does
occur, there will be no substantial present or
potential hazard to human health or the environment
(not available for new underground tank systems or
components due to Section 3004(o)(4) of RCRA).
The purpose of this volume (Volume II) of EPA's technical resource document
for variances from secondary containment of hazardous waste tank systems is to
provide guidance both to applicants seeking a risk-based variance and to
permit writers reviewing risk-based variance demonstrations.
BACKGROUND
On June 26, 1985, the EPA announced it had determined that a substantial
number of hazardous waste tank systems are likely to be leaking hazardous
waste to the environment and that these releases could present significant
risks to human health and the environment (50 Federal Register 26444). Three
sources of information formed the basis for these determinations:
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OSWER. Directive 9483.00-2
ES-2
Several EPA-sponsored studies;
Information from the public, industry, and state and
local governments, including survey results and
studies; and
Internal EPA information pertaining to damages, or
threats of damage, caused by releases of hazardous
wastes from tank systems.
This information also allowed the EPA to identify th'e major causes of tank
system releases. These causes include external corrosion, tank structural
failure, piping and ancillary equipment failures, improper"tank system
installation, and operator errors. Therefore, the EPA concluded that the best
regulatory strategy for hazardous waste tank systems is one that focuses on
sound primary containment and effective and rapid detection and response to
leaks from the primary containment ^structure. The best means of ensuring
these objectives for most tank systems is secondary containment with
interstitial monitoring. Because technologies may exist which are as
protective of human health and the environment as secondary containment, and
because site-specific factors may exist which indicate that even a worst-case
release of hazardous waste from a tank system would not pose a substantial
present or potential hazard to human health or the environment, the two
variances from secondary containment (i.e., the technology-based and the
risk-based) were developed.
THE RISK-BASED VARIANCE
In order to receive a risk-based variance from the secondary containment
requirements of hazardous waste tank systems, a tank system owner/operator
must demonstrate to the EPA Regional Administrator (or State Official) that a
release from the tank system will not pose substantial present or potential
hazard to human health or the environment. A risk-based variance
demonstration requires the permit applicant to determine the following (40 CFR
264.l93(g)(2) (51 Federal Register 25475, July 14, 1986)):
(i) The potential adverse effects on ground water, surface water,
and land quality taking into account:
(A) The physical and chemical characteristics of the waste in
the tank system, including its potential for migration;
(B) The hydrogeological characteristics of the facility and
surrounding land;
(C) The potential for health risks caused by human exposure
to waste constituents;
(D) The potential for damage to wildlife, crops, vegetation,
and physical structures caused by exposure to waste
constituents; and
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OSWER Directive 94.83.00-2
ES-3
(E) The persistence and permanence of the potential adverse
effects/
(ii) The potential adverse effects of a release on ground-water
quality, caking into account:
(A) The quantity and quality of ground water and the
direction of ground-water flow;
(3) The proximity and withdrawal rates of ground-water users;
(C) The current and future uses of ground water in the area;
and
(D) The existing quality of ground water, including other
sources of contamination and their cumulative impact on
__ . the ground-water quality.
(iii) The potential adverse effects of a release on surface water
quality, faking into account:
(A) The quantity and quality of ground water and the
direction of ground-water flow;
(B) The patterns of rainfall in the region;
(C) The proximity of the tank system to surface waters;
(D) The current and future uses of surface waters in the area
and any water quality standards established for those
surface waters; and
(E) The existing quality of surface water, including other
sources of contamination and the cumulative impact on
surface water quality.
(iv) The potential adverse effects of a release on the land
surrounding the tank system, taking into account:
(A) The patterns of rainfall in the region; and
(B) The current and future uses of the surrounding land.
Because the appropriateness of a risk-based variance is determined by
site-specific conditions, development of a risk-based variance demonstration
requires extensive site-specific data. Therefore, this volume identifies the
following: (1) the types of site-specific data that will generally be
required for a risk-based variance demonstration; (2) potential sources of the
required information; and (3) how the data are to be used in the demonstration.
A written notice of an owner/operator's intent to conduct and submit a
demonstration for a risk-based variance from secondary containment of a
hazardous waste tank system or component must be received by the U.S. EPA
Regional Administrator (or State Official) within specific statutory deadlines
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OSWER Directive 9483.00-2
ES-4
(40 CFR 264.193(h)(l) (51 Federal Register 25476)). Furthermore, the
risk-based variance demonstration must be completed and received by the U.S.'
EPA Regional Administrator (or State Official) no more than 180 days after the
written notice of intent to apply. Failure to meec these deadlines may result
in the tank system or component becoming ineligible for the risk-based
variance.
The risk-based variance application as described in Volume II is composed
of essentially two parts:
a health effects evaluation; and
an environmental impact evaluation.
Both initially require similar information (e.g., physical, chemical, and
toxicological characteristics of the waste, hydrogeological characteristics of
the ajrea, predicted exposure point concentrations). The health effects
"evaluation uses this information to estimate human health risk, while the
environmental impact evaluation uses the information to describe the potential
for damage to wildlife, crops, vegetation, and physical structures.
The steps described within this volume for completing the health effects
evaluation are listed below.
1) Obtain information on the waste constituents, and
select indicator chemicals (either all of or a subset
of the chemicals handled within the tank system(s)).
This step involves specifying the physical and
chemical characteristics of the constituents,
determining whether the use of indicator chemicals is
appropriate and, if so, selecting indicator chemicals,
and determining the potential worst-case release
volumes.
2) Obtain information on the hydrogeology and surrounding
environment. This step includes determining the
proximity of the tank system to surface water and
ground-water, the direction and velocity of
ground-water flow, the depth and composition of the
unsaturated zone, the patterns of regional rainfall,
the current and future uses of ground water, surface
waters, and the surrounding land, and the existing
quality of ground water and surface water.
3) Identify current and future potential exposure
pathways and estimate the exposure point
concentrations of the indicator chemicals. If no
current or future exposure pathways exist, then the
demonstration of no substantial hazard is complete.
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OSVER Directive 9483.00-2
ES-5
4) Compare the exposure point concentrations to
established water and air quality standards. If
acceptable established quality standards exist for all
indicator chemicals, then the application is complete.
5) Estimate human intakes at the exposure points.
6; Assess the subchronic and chronic noncarcinogenic and
potential carcinogenic toxicities of the chemicals.
7) Combine tha intakes with the toxicities to provide an
indication of the health risk.
The first three steps of the health effects evaluation (i.e., selecting
indicator chemicals, obtaining site-specific information, and estimating
exposure point concentrations), are identical to the first three steps of the
environmental impact evaluation. The remaining seep of the environmental
impact evaluation involves a description of how the estimated exposure point
concentrations will adversely affect the environment.
The level of detail required in the application is site-specific; it is
affected by the particular waste streams handled, the tank system, the local
hydrogeology, and the potential for .human and environmental exposure. The
applicant may decide to use a screening method for assisting in the decision
of whether or not to proceed with the potentially expensive risk-based
variance application. The other options are to seek a technology-based
variance (Volume I') or comply with the secondary containment requirements.
The risk-based variance application is expected to parallel this volume of
the technical resource document. That is, chapters or sections in the
application should correspond to Chapters 2 through 8 of Volume II.
Applicants will use their own discretion concerning which information is more
appropriate as text ana which is more appropriate as appendices to the
application. Worksheets are also provided throughout the document. All are
partially completed with illustrative examples, and blank worksheets are
provided. These worksheets, or reasonable facsimiles, are to be filled out
and submitted as part of the risk-based variance application.
An approach is recommended for summarizing the results, assumptions, and
uncertainties of the risk-based variance analysis, for drawing a conclusion,
and for preparing the supporting documentation. A variety of appendices are
also provided. One appendix provides applicants with a procedure for helping
decide whether to apply for a risk-based variance. This screening procedure
consists of a series of questions to help the applicant identify tank systems
that are exempt from the secondary containment requirement, tank systems that
are not eligible for a risk-based variance, the basis for the risk-based
variance, and potential future data gathering efforts. Another appendix
provides a list of federal and state agencies, regional EPA offices and
private organizations. These sources will be helpful in providing information
for assessing surrounding land use, water use, and water quality
characteristics. Still other appendices consist of data tables that contain
key quantitative parameters for more than 260 chemicals, a description of the
procedure used for determining toxicity constants for the selection of
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OSWER Directive 9483.00-2
ES-6
indicator chemicals, and blank copies of all worksheets presented in this
volume of the technical resource document.
The EPA developed the risk-based variance for hazardous waste tanks in the
context of other EPA rulos, policies, and guidelines. These include the
Ground-Water Protection Strategy (GWPS), the Location Standards (hydrogeologic
vulnerability criteria), the Alternative Concentration Limit (ACL)
Demonstration Guidance, the Superfund Exposure Assessment Manual, the
Superfund Public Health Evaluation Manual, and the EPA Risk Assessment
Guidelines, among others. Each document has a unique and specific purpose;
however, the risk-based variance document incorporates .'the appropriate
methodologies from the above documents that are relevant to developing a
risk-based variance demonstration. As a result, the risk-based variance
document provides consistent EPA policy and procedural recommendations for
assessing risk associated with the release of contaminants from hazardous
waste tanks.
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OSWER Directive 9483.00-2
CHAPTER 1
INTRODUCTION
The purpose of this volume (Volume II) of EPA's technical resource
document for variances from secondary containment of hazardous waste tank
systems is to provide guidance both co applicants seeking a risk-based
variance and uo permit writers reviewing risk-based variance
demonstrations.1-1 According to 40 CFR 264.183 (g) (2) (51. Federal Register
2547S, July 14, 1986),2Jin order to receive a risk-based variance from the
secondary containment requirements of 40 CFR 264.193(a)-(f) (51 Federal
Register 25474, July 14, 1986), a tank system owner or operator must
demonstrate to the EPA Regional Administrator1-1 that a release from the tank
system will not pose substantial present or potential hazard to human health
or the environment.UJ The risk-based variance only provides an exemption
from the secondary containment -requirements.. The tank system is still subject
to all other requirements, such as corrosion protection, integrity
assessments, inspections, and corrective action. A risk-based variance
demonstration requires the permit applicant to determine the following (40 CFR
264.193(g)(2) (51 Federal Register 25475, July 14, 1986)):
(i) . The potential adverse effects on ground water, surface water,
and land quality taking into account:
(A) The physical and chemical characteristics of the waste in'
the tank system, including its potential for migration
(Chapter 2);SJ
1J Many states have developed non-degradation policies that prohibit or
severely restrict the release of pollutants into the ground water. In such
states, a risk-based variance from the secondary containment regulations may
not be allowed unless the applicant can demonstrate that a release will not
reach the ground water. Before attempting to obtain a risk-based variance,
the prospective applicant should first check with the appropriate state
government agency responsible for ground-water protection to determine whether
a risk-based variance would be permissible under applicable state laws.
IJ All references to regulations for owners and operators of permitted
hazardous waste facilities (40 CFR 264) also apply to interim status standards
for owners and operators of hazardous waste facilities (40 CFR 265).
1J In states that have received authorization from EPA to implement the
RCRA program, demonstratons should be made to the cognizant State officials.
Hereinafter, the term Regional Administrator refers to either the EPA or the
State official as appropriate.
<>J The risk-based variance provision does not apply to new underground
tank systems or components. Consequently, owners and operators must install
secondary containment for new underground tank systems or components (51
Federal Register 25424, July 14, 1986).
*J The chapters in parentheses refer to this volume of the technical
resource document.
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OSWER Directive 9483.00-2
1-2
(B) The hydrogeological characteristics of the facility and
surrounding land (Chapter 3);
(C) The potential for health risks caused by human exposure to waste
constituents (Chapters 5 and 6);
(D) The potential for damage to wildlife, crops, vegetation, and
physical structures caused by exposure to waste constituents
(Chapter 7); and
(E) The persistence and permanence of the potential adverse effects
(Chapter 2).
(ii) The potential adverse effects of a release on ground-water quality,
taking into account:
(A) The quantity and quality of ground water and the direction of
ground-water flow (Chapters 3 and 4);
(B) The proximity and withdrawal rates of ground-water users
(Chapter 4);
(C) The current and future uses of ground water in the area,
(Chapter 4); and
(D) The existing quality of ground water, including other sources of
contamination and their cumulative impact on the ground-water
quality (Chapter 4).
(iii) The potential adverse effects of a release on surface water quality,
taking into account:
(A) The quantity and quality of ground water and the direction of
ground-water flow (Chapters 3 and 4) ;
(B) The patterns of rainfall in the region (Chapter 3);
(C) The proximity of the tank system to surface waters (Chapter 3);
(D) The current and future uses of surface waters in the area and
any water quality standards established for those surface waters
(Chapter.4); and
(E) The existing quality of surface water, including other sources
of contamination and the cumulative impact on surface water
quality (Chapter 4).
(iv) The potential adverse effects of a release on the land surrounding
the tank system, taking into account:
(A) The patterns of rainfall in the region (Chapter 3); and
(B) The current and future uses of the surrounding land (Chapter 4).
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OSWER Directive 9483.00-2
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Because the appropriateness of a risk-based variance is determined by
site-specific conditions, development of a risk-based variance demonstration
requires extensive site-specific data. Therefore, this volume identifies the .
following: (1) the types of site-specific data that will generally be
required for a risk-based variance demonstration; (2) potential sources of the
required information; and (3) how the data are to be used in the demonstration.
In addition to requiring site-specific data, the risk assessment process
requires the use of some site-specific procedures as well. For example,
selection of appropriate soil and ground-water transport models depends on
site-specific conditions. Thus, this volume does not specify how transport
modeling is to be done, but instead provides general concepts, basic guidance,
and sources of information on modeling. For other parts af the risk
assessment process, such as determining chemical toxicity values,
site-specific procedures are not required. In these instances, specific
guidance is provided on how the risk assessment should be conducted. Where
step-by-step procedures are not provided^_extensive background discussion also
is not provided. This is based on the assumption that an experienced
professional would be needed to select the appropriate procedures.
Suggestions of the type of professional needed for a particular situation are
provided throughout this volume.
Before continuing, some terminology used in this volume in relation to
hazardous waste tanks must be defined so that the reader has a clear
understanding of what is being discussed. These terms and their definitions
are listed below:
tank - a stationary device designed to contain an
accumulation of hazardous waste that is constructed
primarily of non-earthen materials (e.g., wood,
concrete, steel, plastic) that provide structural
support (40 CFR 260.10 (51 Federal Register 25471,
July 14, 1986)).
tank system - a hazardous waste storage or
treatment tank and its associated ancillary equipment
(defined below) and containment system (if any) (40
CFR 260.10 (51 Federal Register 25471, July 14,
1986)), or a series of interconnected storage and/or
treatment tanks that handle the same waste and their
ancillary equipment and containment systems.
ancillary equipment '- any device that is used to
distribute, meter, or control the flow of hazardous
waste from its point of generation to a storage or
treatment tank(s), between storage and/or treatment
tanks, to a point of disposal on site, or to a point
of shipment for disposal off site (40 CFR 260.10 (51
Federal Register 25471, July 14, 1986)). Ancillary
equipment includes piping, fittings, flanges, valves,
and pumps.
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OSVER Directive 9483.00-2
1-4
tank system component - the individual tank(s) or
ancillary equipment associated with a tank system (40
CFR 260.10 (51 Federal Register 25471, July 14,
1986)).
tank system cluster - a group of tank systems that
are in close enough proximity such that the transport
of releases from the tank systems could be modeled
realistically by aggregating the release volumes and
chemical masses from the tank systems.
Exhibit 1-1 illustrates the use of these terms at a hypothetical facility. In
addition to the- above terms, the reader should be aware of'the precise
definitions of the four types of hazardous waste tanks referred to in this
volume. These definitions are as follows (as defined in 40 CFR 260.10 (51
Federal Register 25471, July 14, 1986)):
aboveground tank - a tank that is situated such
that the entire surface area of the tank is completely
above the adjacent surrounding surface and the entire
surface of the tank (including the bottom) can be
visually inspected.
. onground tank - a tank that is situated such that
the bottom of the tank is on the same level as the
adjacent surrounding surface so that the external tank
bottom cannot be visually inspected.
inground tank - a tank that has some portion of the
tank wall situated within the ground, thereby
preventing visual inspection of the external surface
area of the tank that is in the ground.
underground tank - a tank that is totally below the
surface of and covered by the ground.
Some additional terms are identified as needed within the text.
Many facilities have more than one tank system or component that does not
have secondary containment, yet the owner/operator may be applying for a
risk-based variance for only some or one of them. These systems or components
may not have secondary containment because of one of the following reasons:
(1) the system or component is exempt from the secondary containment
requirement (e.g., tank systems that are used to store waste absent of free
liquids and are located within a building with an impermeable floor); (2) the
system or component was previously granted a variance from the secondary
containment requirement; or (3) the existing system or component has not yet
reached 15 years of age.
In applying for a risk-based variance, the applicant must include in the
demonstration of no substantial hazard the tank systems and components for
which the variance is being sought as well as all tank systems or components
previously granted a variance. This inclusion is required because the
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Exhibit 1-1
PLAN VIEW OF HYPOTHETICAL FACILITY
OSWIiH Directive 9483 00 2
Tank System Cluster
Tank System
T51TV-
Tank System
Tank System Cluster
Facility Boundary
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OSWER Directive 9483.00-2
1-6
risk-based variance is'based on no substantial hazard rather than no
incremental substantial hazard. Consequently, for tank facilities that have
several tank systems of different ages, the applicant may want to submit a
variance application that includes all the tank systems for which a variance
will eventually be sought. This procedure would avoid the necessity of future
revisions to the risk-based variance application. In submitting revisions to
an application, the additional tanks may result in substantial hazard. In
this situation, the tank components which were previously granted a variance
would be allowed to continue to operate without secondary containment and the
additional tanks would not be granted a variance. For example, if tank A has
previously been granted a risk-based variance and tank 8 is presently being
evaluated for a risk-based variance, then the demonstration for tank B must
include tank A in the evaluation. The 'reason for this inclusion is tank A may
still release its hazardous waste even though it has been granted a risk-based
variance. To assess the cumulative effect of this risk and the incremental
risk from tank B, both must be considered together. If tanks A and B pose a
substantial hazard, then tank B must be fitted with secondary containment.
Tank A would still retain its variance.
The remainder of this chapter is organized as follows. Section 1.1
provides an overview of the variance demonstration process. Section 1.2
describes the relationship of this demonstration process to other
environmental protection rules, policies, and guidelines. Section 1.3
discusses the procedures necessary to begin the variance application
process.SJ Finally, Section 1.4 describes the organization of the remainder
of this volume.
1.1 OVERVIEW OF THE RISK-BASED VARIANCE APPLICATION PROCESS
The risk-based variance application is composed of essentially two parts:
a health effects evaluation; and
an environmental impact evaluation.
Both initially require similar information (e.g., physical, chemical, and
toxicological characteristics of the waste, hydrogeological characteristics of
the area, predicted exposure point concentrations). The health effects
evaluation uses this information to estimate human health risk, while the
environmental impact evaluation uses this information to describe the
potential for damage to wildlife, crops, vegetation, and physical structures.
(It should be noted, however, that many environmental impacts also affect
human health risk and should, therefore, be considered in the health effects
evaluation as well as the environmental impact evaluation. For example, if
crop contamination were to result in ingestion of contaminated food by humans,
then this type of exposure should be considered in the health effects
evaluation.)
tj Prior to applying for the variance, the applicant must provide
written notice of intent to apply, accompanied by a schedule of the process,
to the Regional Administrator (40 CFR 264.193(h) (51 Federal Register 25476)).
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OSWER Directive 9483.00-2
1-7
The steps described within this volume for completing the health effects
evaluation are listed belov.
1) Obtain information on the waste constituents, and
select indicator chemicals (either all of or a subset
of the chemicals handled within the tank system(s))
(Chapter 2).
2) Obtain information on the hydrogeology and surrounding
environment (Chapters 3 and 4).
3) Identify current and future potential exposure
pathways and estimate the exposure point
concentrations of the indicator chemicals (Chapter
5). If no exposure pathways exist, then the
demonstration of no substantial hazard is complete.
4) Compare the exposure point concentrations to
established quality standards (Chapter 6, Section 1).
If acceptable established standards exist for all
indicator chemicals, then the health effects
evaluation is complete.
5) Estimate human intakes at the exposure points (Chapter
6, Section 2).
6) Assess the subchronic and chronic noncarcinogenic and
potential carcinogenic toxicities of the chemicals
(Chapter 6, Section 3).
7) Combine the intakes with the toxicities to provide an
indication of the health risk (Chapter 6, Section 4).
The first three steps of the health effects evaluation (i.e., selecting
indicator chemicals, obtaining site-specific hydrogeologic information, and
estimating exposure point concentrations (Chapters 2 through 5)), are
identical to the first three steps of the environmental impact evaluation and,
therefore, will already be completed. The remaining step of the environmental
impact evaluation will involve a description of how these concentrations will
adversely affect the environment (Chapter 7).
The level of detail required in the application is site-specific; it is
affected by the particular waste streams handled, the tank system, the local
hydrogeology, and the potential for human and environmental exposure. The
applicant may decide to use a screening method (see Appendix A) for assisting
in the decision of whether or not to proceed with the potentially expensive
risk-based variance application. The other options are to-seek a
technology-based variance (Volume I) or comply with the secondary containment
requirements.
The risk-based variance application should parallel this volume of the
technical resource document. That is, chapters or sections in the application
should correspond to Chapters 2 through 8. The applicant should use his or
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OSWER Directive 9483.00-2
1-8
her own discretion concerning which information is more appropriate as text
and wich is more appropriate as appendices to the application. Worksheets are
provided throughout the document. All are partially completed with
illustrative examples, and blank worksheets are provided in Appendix E. These
worksheets, or reasonable facsimiles, are to be filled out and submitted as
part of the risk-based variance application. All worksheets should contain
the facility identifier, name of che analyst who completed the worksheet, and
name of the quality control (QC) reviewer.
1.2 RELATIONSHIP TO OTHER RULES, POLICIES, AND GUIDELINES
The EPA developed the risk-based variance for hazardous waste tanks in the
context of other EPA rules, policies, and guidelines. These include the
Ground-Water Protection Strategy (GWPS), the Location Standards (hydrogeologic
vulnerability criteria), the Alternative Concentration Limit (ACL)
Demonstration Guidance, the Superfund Exposure Assessment Manual, the
SuperfundPublie Health Evaluation Manual, and the EPA Risk Assessment
Guidelines, among others. Each document has a unique and specific purpose;
however, this technical resource document incorporates the appropriate
methodologies from the above-mentioned documents that are relevant to
developing a risk-based variance demonstration. As a result, this technical
resource document provides consistent EPA policy and procedural
recommendations for assessing risk associated with the release of contaminants
from hazardous waste tanks. The following discussion describes the purpose
and relationship, of the aforementioned documents.
1.2.1 Ground-Water Protection Strategy (GWPS)
In August 1984, che Environmental Protection Agency (EPA) issued a
Ground-Water Protection Strategy (GWPS) to encourage consistent protection of
ground-water resources across EPA programs (e.g., Superfund cleanups,
hazardous waste tank variances, and underground storage tank requirements).
Through the process of classification, ground-water resources are separated
into hierarchical categories on the basis of their value to society, use, and
vulnerability to contamination. Each class is to be accorded a different
level of protection. The core of the strategy is a differential protection
policy that recognizes that different ground-water resources require different
levels of protection. A three-tiered classification system was established as
the vehicle for implementing this policy.
The Ground-Water Protection Strategy (GWPS) guidance7-1 document for
ground-water classification is a follow-up to the Ground-Water Protection
Strategy that the Environmental Protection Agency (EPA) issued in August of
1984. EPA provided the GWPS Guidelines for public comment via a Federal
Register notice December 3, 1986. The GWPS Guidelines are a major step in
7J EPA> Guidelines for Ground-Water Classification Under the EPA
Ground-Water Protection Strategy, Final Draft, Office of Ground-Water
Protection, December 1986.
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OSVER Directive 9483.00-2
1-9
EPA's efforts to provide policy direction for EPA programs relating to ground
water. The purpose of the GWPS document is two-fold: (I) to further define
the classes, concepts, and key terms related to the classification system
outlined in the Ground-Water Protection Strategy; and (2) to describe the
procedures and information needs for classifying ground water.
The GWPS classification system consists of three general classes of ground
water representing a hierarchy of ground-water resource values to society.
These classes are:
Class I - Special ground water;
Class II - Ground water that is a current 'or
potential source of drinking water; and
Class III - Ground water that is not a current or
-potential source of drinking water.
The classification system is, in general, based on drinking water as the
highest beneficial use of the resource. The system is designed to be used in
conjunction with the site-by-site assessments typically conducted by the EPA
program offices in issuing permits and variances, deciding on appropriate
corrective action, etc.
A site-by-site approach to classifying ground water necessitates
delineating a segment of ground water to which the classification criteria
apply. The EPA has developed a Classification Review Area system that is
based initially on a two-mile radius from the boundaries of the "facility" or
the "activity." Within the Classification Review Area, a preliminary
inventory of public supply wells, populated areas not served by public supply,
wetlands and surface waters, is performed.
Class I ground waters are resources of unusually high value. They are
highly vulnerable to contamination and are: (1) irreplaceable sources of
drinking water; and/or (2) ecologically vital. Ground water that is highly
vulnerable to contamination is characterized by a relatively high potential
for contaminants to enter and/or to be transported within the ground-water
flow system. Ground water may be considered "irreplaceable" if it serves a
substantial population and if delivery of comparable quality and quantity of
water from alternative sources in the area would be economically infeasible or
precluded by institutional constraints. Ground water may be considered
ecologically vital if it supplies a sensitive ecological system located in a
ground-water discharge area that supports a unique habitat.
Class II ground waters are current and potential sources of drinking water
and water having other beneficial uses. All non-Class I ground water
currently used, or potentially available, for drinking water and other
beneficial use is included in this category, whether or not it is particularly
vulnerable to contamination. This class is divided into current sources of
drinking water (Subclass IIA), and potential sources of drinking water
(Subclass IIB).
Ground water is considered a current source of drinking water under two
conditions. The first condition is the presence of one or more operating
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OSWER Directive 9483.00-2
1-10
drinking-water wells (or springs) within the Classification Review Area. The
second condition requires the presence within the Classification Review Area
of a water-supply reservoir watershed-(or portion of a water-supply reservoir
watershed) designated for water-quality protection, by either state or local
government. The concept of a current source of drinking water is rather broad
by intent.
A potential source of drinking water 'is one which is capable of yielding a
quantity of water to a well or spring sufficient for the needs of an average
family. Drinking water is taken specifically as water with a total dissolved
solids (TDS) concentration of less than 10,000 tng/1, which can be used without
treatment, or which can be treated using methods reasonably employed in a
public water-supply system. The sufficient yield criterion has been
established at 150 gallons/day.
Class III ground waters are resources that are not potential sources of
drinking water. These ground waters are of limited beneficial use because
they are either saline^or otherwise contaminated beyond levels which would
allow use for drinking or other beneficial purposes. This class includes
ground waters that: (1) have a total, dissolved solids (TDS) concentration
over 10,000 mg/1; or (2) are so contaminated by naturally occuring conditions,
or by the effects of broad-scale human activity (i.e., unrelated to a specific
activity), that they cannot be cleaned up using treatment methods reasonably
employed in public water-supply systems.
Class III is subdivided primarily on the basis of the degree of
interconnection with surface waters or adjacent ground waters of a higher
class. In addition, Class III encompasses those very rare settings where
there is insufficient ground water within the Classification Review Area at
any depth to meet the needs of an average size family. Such ground waters,
therefore, are not potential sources of drinking water.
The risk-based variance assessment process described in this volume is
conducted on a site-by-site basis and includes a hydrogeologic
characterization consistent with GVPS Guidelines. While the purpose of the
risk-based variance hydrogeologic characterization is not to classify the
site's ground water into Class I, Class II, etc., the risk-based variance
assessment does evaluate all of the same site-specific characteristics used by
the GVPS Guidelines. In general, a risk-based variance is more likely to be
appropriate for tank systems located in areas with Class III ground water.
Tank systems located in areas with Class I ground water are unlikely to be
eligible for a risk-based variance.
1.2.2 Location Standards (Hydrogeologic Vulnerability Criteria)
EPA's Location Standards manual1-1 was prepared in response to the
Hazardous and Solid Waste Amendments of 1984 requirement that EPA publish
IJ EPA, Criteria for Identifying Areas of Vulnerable Hydrogeology
Under RCRA: Statutory Interpretative Guidance Manual for Hazardous Waste
Land Treatment, Storage, and Disposal Facilities, Interim final report
submitted to Office of Solid Waste, July 1986.
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OSWER Directive 9483.00-2
1-11
guidance criteria identifying areas of vulnerable hydrogeology. The purpose
of such location standards is to provide RCRA permit writers with a
standardized technical method for evaluating hydrogeologic data submitted in
hazardous waste land treatment, storage, and disposal facility permit
applications to determine if the facilities are located in "areas of
vulnerable hydrogeology."
EPA considers."areas of vulnerable hydrogeology" to be areas in which the
predominant natural hydrogeological conditions are conducive to the subsurface
migration of contaminants in a manner that may adversely.affect drinking water
sources, sensitive ecological systems, or nearby residents. EPA intends to
incorporate consideration of the hydrogeologic vulnerability of a facility's
location into RCRA permitting decisions. Currently, EPA will only be able to
do so to a limited extent due to the.constraints of existing regulations.
However, once regulations specifying criteria for acceptable locations
required under HSWA Section 3004(0)(7) have been promulgated, EPA will have
much greater flexibility in considering the hydrogeologic vulnerability of a -
facility's location in permitting decisions.
OSW is developing an integrated ground-water strategy that will consider
how such hydrogeologic vulnerability criteria may be applied to facility
permitting decisions (e.g., risk-based variances). In addition, it will
evaluate the relationship of each of the major components of the RCRA program
mandated by HSWA. The integrated OSW ground-water strategy is a response to
the previously discussed 1984 Ground-Water Protection Strategy (GWPS), which
called for program offices to develop policies for ground-water protection
against a broad framework of ground-water classification and-protection. The
OSW strategy not only characterizes the quality and use of ground water, but
also characterizes how vulnerable that ground water is to contamination as a
result of the site's geology.
A risk-based variance demonstration includes a site hydrogeologic
characterization that identifies how vulnerable che potentially affected
ground water is to contamination from a tank site release. Such a site
characterization must consider ail the same factors that would be considered
according to the location standards guidance. Thus, as the location standards
become incorporated into the RCRA permitting process, they can also be used
for evaluating risk-based variances.
1.2.3 Alternate Concentration Limit (ACL) Guidance
The Alternate Concentration Limit (ACL) Guidance*-1 provides guidance for
hazardous waste facilities seeking variances from ground-water background
contaminant concentration levels or RCRA adopted maximum ground-water
contaminant concentration limits (MCLs). The principal elements of the
ground-water protection standard are discussed in 40 CFR 264.90. All land
treatment, storage, and disposal (TSD) units must install a ground-water
*J EPA, Alternate Concentration Limit Guidance Based on Section
264.94(b) Criteria, Part I: ACL Policy and Information Requirements. Draft
report submitted to the Office of Solid Waste, December 1986 (currently
unavailable).
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OSWER Directive 9483.00-2
1-12
monitoring program to ensure that ground-water standards are met. For each
hazardous constituent entering the ground water from a regulated unit,
background concentrations or MCLs establish the limit beyond which degradation
of ground-water quality will not be allowed.
Variances from these standards, in the form of an ACL, are available if
the applicant can demonstrate that alternative constituent concentration
levels will not pose a substantial present or potential hazard to human health
or the environment. An ACL demonstration requires not only characterizing the
site hydrogeology, similar to that done for the Location Standards, but also
characterizing the hazardous waste constituents from the- point of release to
the point of exposure. 40 CFR 264.94 discusses the "Alternate Concentration
Limit" and lists 10 criteria to be applied in ACL demonstrations.
An ACL demonstration is essentially a risk assessment and risk management
process in which a determination of acceptable ground-water contamination is
made. Site-specific information, such as local hydrogeologic characteristics,
the facility's waste constituents,"and local environmental factors, is needed
to assess the potential impact on human health and the environment of each
hazardous constituent present in the ground water..
To establish ACLs, two points must be defined on a RCRA facility's
property: (1) the point of compliance (POC); and (2) the point of exposure
(POE). The POC is the point in the uppermost aquifer, on the immediate
downgradient side of the RCRA regulated unit, where ground-water monitoring
takes place and the ground-water protection standard is set. The ACL, if it
is established, would be set at this point. The POE, on the other hand, is
the point at which it is assumed a potential receptor can come in contact with
the ground water. Therefore, the ground-water quality at the POE must be
protective of that receptor.
While both the ACL demonstration and risk-based variance process for
hazardous waste tanks require site-specific risk assessments, the ACL process
depends on ground-water monitoring to ensure that the ACL will not be
exceeded. Such ground-water monitoring is already required at all land TSD
units according to 40 CFR 264.97. The risk-based variance demonstration for
tanks, however, does not rely on ground-water monitoring to establish and
monitor an acceptable level of contamination. Instead, the risk-based
variance demonstration for tanks depends on an analysis of a potential
worst-case release and the demonstration that, because of the tank system's
combination of waste composition and the hydrogeology of the site, even a
worst-case release will not pose a substantial present or potential risk to
human health and the environment.
1.2.4 Super-fund Exposure Assessment and Public Health Evaluation
Manuals
The Superfund Exposure Assessment18-1 and the Superfund Public Health
Evaluation11-1 manuals provide guidance for conducting portions of the
IOJ EPA, Superfund Exposure Assessment Manual, Draft, Office of
Emergency and Remedial Response, January 1986.
11J EPA, Superfund Public Health Evaluation Manual, Office of Emergency
and Remedial Response, October 1986.
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OSWER Directive 9483.00-2
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remedial investigations (RI) and feasibility studies (FS) for Superfund
sites. The purpose of the remedial investigation is to acquire the field data
needed to determine the extent of existing contamination at the site (in the
absence of any control measures). In the feasibility study, these data are
used to evaluate site-related exposure and present or potential risk to human
health and the environment. The remedial investigation and the feasibility
study are major components in the remedial response process for Superfund
sites.
The risk-based variance demonstration for hazardous .waste tanks, as
described in this volume, is based to a large extent on "the risk assessment
methodologies recommended in the Superfund Public Health Evaluation Manual.
Much of the guidance on exposure assessment is based on the Superfund Exposure
Assessment Manual. The methods recommended in these manuals are particularly
appropriate because the hazardous waste tank risk-based variance requires the
evaluation of risk posed by a presumed worst-case uncontrolled release. In
addition, these manuals have already been successfully used for Superfund
sites.
Superfund Exposure Assessment Manual
The Superfund Exposure Assessment Manual presents an integrated
methodology for the analyses conducted during the RI/FS. This methodology
includes the following three major components required to assess human
population exposure to contaminants released from uncontrolled hazardous waste
sites: (1) analysis of toxic contaminants released from a subject site; (2)
determination of the environmental fate of such contaminants; and (3)
evaluation of the nature and magnitude of human population exposure to toxic
contaminants. These major analytical components are conducted in sequence to
qualitatively and quantitatively track the migration of contaminants through
environmental media to points of contact with human populations.
The general framework for conducting an integrated exposure'analysis
involves identifying each on-sice source of each target chemical release to
specific environmental media. Emissions are characterized by types and amount
of chemicals involved, and a determination is made of the level of release
(mass loading) of each chemical to each affected medium. The results of the
release analysis step provide the basis for evaluating the potential for
contaminant transport or transformation and environmental fate. This analysis
is also chemical- and medium-specific.
Environmental fate analysis produces results that describe the extent and
magnitude of environmental contamination (i.e., contaminant concentrations in
specific environmental media). These results are used to predict human
population contact with chemicals emanating from the site. Exposed population
analysis results in the identification, enumeration, and characterization of
those population segments likely to be exposed. The assessment concludes with
an integrated exposure analysis. In this step, individual chemical-specific
exposure estimates for each exposure route (i.'e., inhalation, ingestion of
drinking water and/or food, dermal contact) are developed. In cases where a
population group experiences more than one exposure by a given route,
exposures are summed to develop a cumulative exposure value for the route
involved.
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OSWER Directive 9483.00-2
1-14
The Superfund Exposure Assessment manual is designed for three specific
purposes. First, the overall analytical process outlined provides a framework
for the comprehensive assessment of human exposure associated with
uncontrolled hazardous waste sites. It ensures that all pertinent contaminant
releases and exposure routes are considered, and that an appropriate level of
analytical detail is applied to each component of the evaluation to support
the public health evaluation process. Second, application of this framework
supports the development of exposure assessments that are consistent from site
to site. That is, application of the same analytical philosophy and overall
procedure to each site will ensure that results obtained are comparable among
sites, and will provide a means of documenting that each' site receives
adequate evaluation. Third, the procedures presented in this manual reflect
state-of-the-art methods for conducting the various component analyses that
make up an exposure assessment.
Superfund Public Health Evaluation Manual
The Superfund Public Health Evaluation Manual details the information
requirements and analytical procedures necessary to conduct a public health
evaluation during a feasibility study. The public health evaluation component
of the feasibility study defines the type and extent of hazards to public
health presented by a Superfund site in the absence of remedial action. It is
based in large part on the previously discussed exposure assessment that
evaluates: (1) the type and extent of contamination released from a site to
the environmental media; (2) the environmental transport and transformation of
contaminants following releases; and (3) the magnitude of contact with human
populations.
The results of the exposure assessment may aid the public health
evaluation in one of two ways. Measured or estimated environmental
contaminant concentrations can be compared with public health standards or
criteria that identify acceptable concentrations of contaminants in specific
environmental media. This comparison is used to directly assess the potential
public health impact. Alternatively, in the absence of such
standards/criteria, the public health evaluation process evaluates exposure
estimates using relevant toxicological data to determine the magnitude of the
health hazard posed by the uncontrolled site.
The Suparfund Public Health Evaluation Manual covers the two key elements
of a public health evaluation that should be addressed in any feasibility
study: (1) the baseline public health evaluation; and (2) the public health
analysis of remedial alternatives. A baseline public health evaluation is an
analysis of site conditions in the absence of remedial action. It provides
the remedial project manager with an understanding of the nature of chemical
releases from the site, the pathways of human exposure, and a measure of the
threat to public health as a result of releases. The information developed in
the baseline analysis provides input for developing and evaluating remedial
alternatives. In addition, the baseline evaluation satisfies the National Oil
and Hazardous Substances Pollution Contingency Plan (NCP) requirement to
complete a detailed analysis of the no-action alternative, 'including an
evaluation of public health impacts.
Development of design goals for remedial alternatives is the second key
phase of the public health evaluation. The manual describes specific
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OSVER Directive 9483.00-2
1-15
procedures for comparing health risks and developing design goals for remedial
measures. The process builds on information collected and evaluated in the
baseline evaluation and closely follows the guidelines in the NCP and EPA's
policy on CERCLA compliance with the requirements of other environmental
statutes.
The public health evaluation guidance provides a framework that must be
adapted to individual site characteristics. These site characteristics
include the following:
number and identity of chemicals present;
availability of appropriate standards and/or
toxicity data;
number and complexity of exposure pathways
(including complexity of release sources and transport
media);
necessity for precision of the results, which in
turn depends on site conditions such as the extent of
contaminant migration, proximity, characteristics and
size of potentially exposed populations, and
enforcement considerations (additional quantification
may be warranted for some enforcement'sites); and
quality and quantity of available monitoring data.
The Superfund Public Health Evaluation Manual provides the recommended
procedures for comparing the different risk estimates obtained from the
exposure assessments for alternative clean-up strategies. The results of both
the exposure and the public health assessments provide critical information
for those responsible for the selection and implementation of remedial options
at Superfund sites.
1.2.5 EPA Guidelines for Health Risk Assessments12-1
In September 1986 (51 Federal Register 33992, September 24, 1986) EPA
issued five guidelines for assessing the health risks of environmental
pollutants. These guidelines are as follows:
Guidelines for Carcinogen Risk Assessment;
Guidelines for Estimating Exposures;
Guidelines for Mutagenicity Risk Assessment;
12J Other useful risk assessment information can be found in the
following document: EPA, Superfund Risk- Assessment Information Directory,
Office of Information Resources Management and Office of Toxic Substances,
November 1986.
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OSWER Directive 9483.00-2
1-16
Guidelines for the Health Risk Assessment of
Suspected Developmental Toxicants; and
Guidelines for the Health Risk Assessment of
Chemical Mixtures.
The risk-based variance for hazardous waste tanks is consistent with the
guidelines mentioned above, and, in particular, uses the Guidelines for
Estimating Exposures and the Guidelines for the Health Risk Assessment of
Chemical Mixtures as a basis for some of the procedures documented in this
manua1.
The Guidelines for Estimating Exposures (51 Federal Register 34042,
September 24, 1986) emphasize that risk assessments will be performed on a
case-by-case basis, and provide a general framework for carrying out human or
non-human exposure assessments. The document lays out a set of questions to
be considered in carrying out an exposure assessment, and these questions have'
been incorporated into the risk-based variance manual. TheTTjuide lines
emphasize that reliable measurements should be used wherever possible to
complement modeling, and that the exposure assessment process should be
coordinated with the toxicity effects assessment. The exposure assessment is
divided into a preliminary phase in which data are compiled and the most
likely areas of exposure are identified. Results from the preliminary phase
are then compiled with toxicity information to perform a preliminary risk
analysis and to decide whether an in-depfh exposure assessment is necessary or
there is no need for further exposure information. Because the assessment of
a risk-based variance is based on potential exposure to chemicals, it is
always necessary to perform the in-depth analysis based on modeling of a leak
from the tank.
The Guidelines for the Health Risk Assessment of Chemical Mixtures (51
Federal Register 34014, September 24 1986) are designed to promote a
consistent Agency approach for evaluating data on chronic and subchronic
effects of chemical mixtures. The document emphasizes the principles of
various sciences that are necessary to assess health risk from exposure to
chemical mixtures, and discusses procedures for the analysis and evaluation of
the available data. Because of uncertainties inherent in predicting the
magnitude and nature of toxicant interactions, the assessment of health risk
from chemical mixtures must include a thorough discussion of all assumptions;
the guidelines recommend different approaches to risk assessment depending on
the nature and quality of the data. The complexity of the issue, and the
relative paucity of empirical data upon which to base generalizations, led the
Agency to emphasize flexibility, judgment, and a clear articulation of the
assumptions and limitations in risk assessments of chemical mixtures.
For each risk assessment, the uncertainties should be discussed and the
overall quality of the risk assessment should be documented. The guidelines
discuss the uncertainties and limitations in some detail, and document
mathematical models for the measurement of joint action of chemicals. The
evaluation of risk for the risk-based variance demonstration uses the same
mathematical models to calculate hazard indices and carcinogenic incremental
risk as presented in EPA's Guidelines for Health Risk Assessment of Chemical
Mixtures.
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OSWER.Directive 9483.00-2
1-17
1.3 INITIATING THE VARIANCE APPLICATION
Before beginning the risk-based variance demonstration, some initial steps
must be completed. The first is that a written notice of an owner's or
operator's intent to conduct and submit a demonstration for a risk-based
variance from secondary containment of a hazardous waste tank system or
component must be received by the U.S. EPA Regional Administrator within
specific statutory deadlines (40 CFR 264.193(h)(1) (51 Federal Register
25476)) (see Appendix A, Section A.2.1.4). Furthermore, the risk-based
variance demonstration must be completed and received by the U.S. EPA Regional
Administrator no more than 180 days after the written notice of intent to
apply. Failure to meet these deadlines may result in the 'tank system or
component becoming ineligible for the risk-based variance.
The written notice of intent to apply must include the following:
(1) a map, with accompanying text, indicating facility location;
(2) a map, with accompanying text, indicating the location and other
identifying characteristics of each tank system or component
that will be included in the variance demonstration;
(3) the age of each tank system or component (if unknown, then
facility age);
(4) a description of the steps being followed to demonstrate no
substantial hazard;
(5) a timetable for completing each of the steps; and
(6) a quality assurance plan.
Worksheet 1-1 is provided for addressing items 4 and 5. When completed, it
can be submitted as part of the notice of intent to apply. The sheet contains
a "milestone" chart for indicating the anticipated completion date of each
step. Place a check mark under the appropriate week and include the actual
date.
Another step that is part of the written notice of intent to apply is the
development of a quality assurance (QA) plan. It is the Office of Solid
Waste's policy11-1 that all data will be scientifically valid, defensible,
and of known and acceptable precision and accuracy. The data will be of
sufficient known quality so as to withstand scientific and legal challenge
relative to the use for which the data are obtained. To ensure that the data
are of known and acceptable quality, adequate QA must be applied throughout
the data-generating process. To achieve this goal, data quality objectives
must be specified prior to data collection activities. This aspect of the
llj EPA, Quality Assurance Program Plan for the Office of Solid Waste,
Office of Solid Waste, September 1986.
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OSVVI H Directive 9483 00-2
WORKSHEET 1-1
TIMETABLE FOR DEMONSTRATION OF RISK-llASKD VARIANCE FROM SECONDARY CONTAINMENT
INSTRUCTIONS:
I. lill In Slnrliug Dole and Finishing l>nlv.
2. IMncc a V at expected lime of completion (or each acllvlly.
3. Next to *". place expected tlnlc In parenthesis (e.g., (10/25/88))
Facility II):
Dale:
Analyst:
Quality Control:
Starling Dale
ACTIVITY
Finishing Dale
WEEK
123456 7 8 9 10 II 12 13 14 IS 16 17 18 19 20 21 22 23 24 25 26
I. Source Characterization
a. Identify Physical and Chemical
Characteristics of Constituents
b. Select Indicator Chemicals
c. Determine Worst Case Release
Volumes
II. llydrogeological Characteristics
a. Characterize Climate
b. Characterize Regional and Site
Geology
c. Characterize Unsaturated and
Saturated Zones
d. Characterize Surface Water
III. Surrounding Land Use, Water Use,
and Water Quality Characteristics
a. Characterize Ground-Water Use and
Quality
b. Characterize Surface Water Use and
Quality
c. Characterize Surrounding Land Use |
and Oualilv L
and Quality
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OSWI H Directive 9483 00-2
WORKSHEET 1-1
TIMETABLE FOR DEMONSTRATION OF RISK-BASED VARIANCE FROM SECONDARY CONTAINMENT
(Continued)
Starling Dale
Finishing Dale
WEEK
ACTIVITY
1 2 3 4 5 6 7 8 9 10 Jl 12 13 14 IS 16 17 18 19 20 21 22 23 24 25 26
IV. Exposure Point Concentration
a. Identify Exposure Pathways
b. Estimate Exposure Point Concentrations
V. Health Effects Evaluation
a. Compare Exposure Point
Concentrations to Established
Health Standards
b. Estimate Chemical Intakes
c. Determine Chemical Toxicities
d. Characterize Risk
VI. Environmental Impact Evaluation
a. Compare Exposure Point
Concentrations to Quality
Standards
b. Derive Site Specific Criteria
c. Evaluate Site Specific Exposure
Points
VII. Preparation of the "No-Substantial
Hazard" Demonstration
a. Summarize Results of the
Risk-Based Assessment
b. Prepare Supporting
Documentation
c. Submit to Regional Administrator
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OSWER Directive 9483.00-2
1-20
initial phase of planning is the basis for the QA plan that is developed. The
QA plan becomes the basis for monitoring and evaluating data collection
activities to ensure that the data quality objectives are met. Part of this
plan has already been incorporated into the worksheets by a requirement that
the quality control (QC) reviewer initial the'worksheet.
Again, submission of, the demonstration for a risk-based variance (see
Chapter 8) must be no more than 180 days after providing written notice of
intent to apply. Therefore, the timetable in Worksheet 1-1 extends across ISO
days, beginning with the submission of written notice of intent to apply and
ending with the submission of the variance application.
1.4 ORGANIZATION OF TECHNICAL RESOURCE DOCUMENT: VOLUME II
The remainder of this volume of EPA's technical resource document for
variances from secondary containment of hazardous waste tank systems is
organized as follows:
Chapter 2 -- Source Characterization
This chapter describes methods for characterizing the potential
source of contamination. The source characterization includes:
(1) specifying the physical and chemical characteristics of the
constituents; (2) determining whether the use of indicator
chemicals is -appropriate and, if so, selecting indicator
chemicals; and (3) determining the potential worst-case release
volumes.
Chapter 3 -- Hydrogeologic Characterization
This chapter discusses the recommended approach for
characterizing the hydrogeology surrounding the tank system and
facility. Such characterizations include: (1) determining the
proximity of the tank svstem to surface water and ground-water;
(2) direction and velocity of ground-water flow; (3) depth and
composition of the unsaturated zone; and (4) patterns of
regional rainfall.
Chapter 4 -- Surrounding Land Use, Water Use, and Water Quality
Characteristics
The methodologies for determining surrounding water use and water
quality characteristics are described in this chapter. In this
chapter the applicant examines: (1) the proximity and withdrawal
rates of ground-water uses; (2) the current and future uses of ground
water, surface waters, and the surrounding land; and (3) the existing
quality of ground water and surface water.
Chapter 5 -- Identifying Exposure Pathways and Estimating Exposure
Point Concentrations
This chapter discusses the estimation of potential exposure point
concentrations. Methodologies for identifying exposure pathways and
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OSWER Directive 9483.00-2
1-21
estimating exposure point concentrations are provided. The estimated
exposure point concentrations are then used in the health and
environmental effects evaluations described in Chapters 6 and 7.
Chapter 6 -- Health Effects Evaluation
This chapter explains the evaluation of potential health effects by:
(1) comparing exposure point concentrations to established acceptable
concentration levels; (2) estimating potential human intake of waste
constituents; (3) determining the chemical toxicity values; and (4)
estimating the potential carcinogenic and non-carcinogenic risks
based on the chemical toxicity values and intake rates.
Chapter 7 - Environmental Impact Evaluation
This chapter describes the evaluation of potential environmental
impacts. Such an .evaluation includes: (1) comparing exposure point
concentrations to established quality standards for ground water,
surface water, and land; and (2) estimating the potential for damage
to wildlife, crops, vegetation, and physical structures.
Chapter 8 -- Summarizing the Risk-Based Variance Application
This chapter describes the recommended approach for summarizing the
results of the risk-based variance analysis and preparing the
supporting documentation.
References
The list of references includes all journal articles, books, and
documents that are cited in the text or footnotes of this volume.
Other useful references are also listed.
Appendix A -- Preliminary Screening for Risk-Based Variance
This appendix provides applicants with a procedure for helping them
decide whether to apply for a risk-based variance. The screening
procedure consists of a series of questions to help the applicant
identify tank systems that are exempt from the secondary containment
requirement, tank systems that are not eligible for a risk-based
variance, the basis for the risk-based variance and potential future
data gathering efforts.
Appendix B -- Information Sources for Environmental and
Hydrogeologic Information
This appendix provides a list of federal and state agencies, regional
EPA offices and private organizations. These sources will be helpful
in providing information for assessing surrounding land use, water
use and water quality characteristics.
Appendix C -- Summary Tables for Chemical-Specific Data
This appendix consists of data tables that contain key quantitative
parameters for more than 260 chemicals. Parameters relate to
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OSVER Directive 9483.00--2
1-22
physical, chemical, fate and toxicological properties of the
chemicals. These specific chemicals are included because of the
amounts of readily available toxicity information rather than because
of their likely presence within hazardous waste tank systems.
Appendix D -- Detailed Procedures for Determining Toxicity
Constants for Indicator Chemical Selection
This appendix describes the procedure used for determining toxicity
constants that are used for the selection of indicator chemicals.
The procedure can be used for specific chemicals^ not listed in
Appendix C.
Appendix E - Blank Worksheets
This appendix includes blank copies of all worksheets presented in
this volume. These worksheets will be completed by the applicant and
submitted as part of the risk-based variance application.
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OSVER Directive 9483.00-2
CHAPTER 2
SOURCE CHARACTERIZATION
This chapter describes the information that is required to characterize
tank systems and components for a risk-based variance application. This
characterization focuses on elements of tank systems that m.iy adversely affect
human health and the environment in the absence of secondary containment.
Section 2.1 presents a methodology for characterizing the physical and
chemical properties of the constituents handled within rank systems. Section
2.2 describes a. procedure for applicants with tank systems that contain many
hazardous waste constituents to rank and select the waste constituents that
are highly toxic, present in high concentrations, and/or are persistent
(indicator chemicals). The final section, Section 2.3, presents a methodology
for estimating potential worst-case release volumes and release masses of
contaminants associated with tank systems. These release volumes and masses
are necessary to estimate exposure point concentrations (see Chapter 5).
Following completion of the procedures discussed in this chapter, the
applicant should have identified information relevant to the particular tank
systems or components for which a variance is sought. Exhibit 2-1 provides an
overview of the source characterization process.
2.1 PHYSICAL, CHEMICAL, AND TOXICOLOGICAL CHARACTERISTICS OF
CONSTITUENTS
The physical and chemical characteristics of the constituents handled
within a tank system determine the transport and fate of the constituents
within the environment. The toxicological characteristics of the constituents
indicate the potential hazard to human health posed by the constituents. This
section presents the characteristics of the constituents that the applicant
(or a qualified professional, such as a toxicologist) should identify and use
in the indicator chemical selection process (Section 2.2). In addition, many
of the characteristics may be used for transport and fate modeling (see
Chapter 5).
2.1.1 Physical and Chemical Properties
Physical and chemical properties that affect transport and fate of
constituents include:
water solubility;
vapor pressure;
Henry's law constant;
organic carbon partition coefficient;
octanol-warer partition coefficient;
persistence (i.e., half-life);
specific gravity;
viscosity; and
oxidation state.
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OSWER Directive 9483.00-
Exhibit 2-1
OVERVIEW OF SOURCE CHARACTERIZATION
SECTION 2.1
Identify physical, chemical and toxicological
characteristics of constituents.
Are less
than'10 to 15
chemicals of concern
handled within
the tank
system?
Yes
1
SECTIt
No
t
ON 2.2
Select Indicator Chemicals:
Idenufy. representative chemical concentrations;
Calculate indicator scores: and
Select indicator chemicals.
1
SECTION 2.3
Calculate potential wor
and indicator chem
st-case release volumes
ical release masses.
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OSWER Directive 9483.00-2
2-3
The applicant should first list all chemicals of concern on Worksheet
2-1. Chemicals (i.e., constituents)' of concern include all RCRA-listed
Appendix VIII hazardous constituents1-1 currently or likely to be handled
within the tank systems for which the applicant is seeking a risk-based
variance or for which a risk-based variance has previously been approved. A
risk-based variance will apply only to the tank systems and chemicals
evaluated in the demonstration of no substantial hazard. Consequently, before
additional chemicals are handled at a future date, the applicant must either
revise and resubmit the risk-based variance application, apply for a
technology-based variance for the tank system(s) handling the new chemicals,
or provide secondary containment for the tank system(s)'handling the new
chemicals.
Next, the applicant should record on Worksheet 2-1 the physical and
chemical properties for each chemical of concern. The Chemical Abstract
Service (CAS) number, water solubility, organic carbon partition coefficient,
vapor pressure and'Henry's law constant can be found for many chemicals In
Exhibit C-l. Half-lives of specific chemicals can be found in Exhibit C-2.
Densities, viscosities, and oxidation states can be obtained from chemical
handbooks.ZJ1J These physical and chemical properties may be used in the
selection of indicator chemicals. They are also usually necessary parameters
for transport models.
For chemicals not listed in Appendix C, the applicant should determine
values using sources listed in Appendix C or other standard references. Also,
estimation techniques are available for many physical/chemical
parameters.kjSj The applicant is encouraged to use estimation techniques
in the absence of experimental data, as long as the procedures are documented.
lj 40 CFR Part 261, Appendix VIII.
lj Robert C. Weast, Ph.D., ed., CRC Handbook of Chemistry and Physics,
64th ed. (Boca Raton: CRC Press, Inc., 1983).
1J Robert C. Reid, John M. Prausnitz, and Thomas K. Sherwood, The
Properties of Gases and Liquids. 3rd ed. (New York: McGraw-Hill, 1977).
"J W.J. Lyman, W.F. Reehl, and D.H. Rosenblatt, Handbook of Chemical
Property Estimation Methods (New York: McGraw-Hill, 1982).
*J W.R. Mabey, J.H. Smith, R.T. Podoll, H.L. Johnson, T. Mill, T.W.
Chou, J. Gates, I.W. Patridge, H. Jaber, and D. Vandenberg, Aquatic Fate
Process Data for Organic Priority Pollutants (Washington, D.C.: Monitoring
and Data Support Division, Office of Water Regulations and Standards, 1982).
-------
WOHKSIIKKT i-\
PHYSICAL AND CHEMICAL CH AHACTER ISTI<-S OF CONSTITUENT!:
INSTRUCTIONS;
1. List all chemicals and tlieir Chemical Abstract Servi.-e
-------
OSWER Directive 9483.00-2
2-5
A brief description of the relevance of each property to potential
chemical release, transport, and fate is given below. Additional discussion
of these parameters is available in numerous references.SJTj*J1J
Water solubility is the maximum concentration of a chemical that
dissolves in pure water at a specific temperature. The solubility of
inorganic chemicals varies widely depending on the nature of the chemical and
the environment it is found in. The pH (acidity/alkalinity) and Eh (redox
potential) will affect solubility by influencing the nature of the soluble
species that are dissolved. Changes in redox potential can cause the release
or removal of inorganics to the soil or sediments. The-type and concentration
of complexing agents present in water will also influence solubility. Organic
compounds will also have variable solubilities which can also be affected by
temperature, pH, and the composition of the solution. Solubilities range from
less than 1 ppb to greater than 100,000 ppm, with most of Appendix VIII
organic compounds falling between 1 and 100,000 ppm.lBJ
Water solubility is a critical property affecting environmental fate.llj
Solubility is one of the factors that controls leachate strength and migration
of chemicals from waste sites (along with sorption potential, soil type, and
water infiltration). Highly soluble chemicals can be rapidly leached from
wastes and contaminated soil and are generally mobile in ground water.
Solubility affects "leachability" into both ground water and surface water,
and highly soluble compounds are usually less strongly adsorbed (and are thus
more mobile) in both ground and surface water. Solubility, along with several
other factors, also affects volatilization from water -- .in general, high
*-' E.E. Kenaga and C.A.I. Goring, "Relationship Between Water
Solubility, Soil-Sorption, Octanol/Water Partitioning, and Bioconcentration of
Chemicals in Biota," in J.G. Eaton, P.R. Parrish, and A.C. Hendricks, Aquatic
Toxicology (Philadelphia: American Society for Testing and Materials, 1978).
Tj W.J. Lyman, W.F. Reehl, and D.H. Rosenblatt, Handbook of Chemical
Property Estimation Methods (New York: McGraw-Hill, 1982).
IJ D.W. Nelson, D.E. Elrich, K.K. Tangi, D.M. Krai, and S.L. Hawkins,
eds., Chemical Mobility and Reactivity in Soil Systems (Proceedings)
(Madison: American Society of Agronomy, The Soil Science Society of America,
1983).
*J A.tf. Maki, K.L. Dickson, and J. Cairns, eds., Biotransformation and
Fate of Chemicals in Aquatic Environments (Washington, D.C.: American
Society for Microbiology, 1980).
IOJ W.J. Lyman, "Solubility in Water," in Lyman, et al., Handbook of
Chemical Property Estimation Methods (New York: McGraw-Hill, 1982).
llj R.E. Menzer and J.O. Nelson, "Water and Soil Pollutants," in J.
Doull, C.D. Klaassen, and M.D. Amdur, Toxicology (New York: MacMillan, 1980):
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OSWER Directive 9483.00-2
2-6
solubility is associated with low volatilization rates.12J Chemicals with
high solubilities also tend to be more readily biodegradable than those with
lower solubilities.1JJ Water solubility is especially important in the
evaluation of aquatic exposure pathways.
Some chemicals may be present at a site at concentrations higher than
their water solubilities. . This situation can arise in the case of non-aqueous
phase liquids (e.g., organic liquids that are not dissolved in water and that
are less dense than water, thereby forming a second liquid layer, which can
float on top of an aqueous phase). Contaminants may be more soluble in these
liquids and be dissolved in the non-aqueous phase at concentrations higher
than their water solubilities.
Vapor pressure and Henry's law constant are two constants useful for
predicting the extent to which a chemical will be released into the air, and
thus are important in evaluating air exposure pathways. Vapor pressure is a
relative measure of the volatility of a chemical in its pure state.lfcj
Vapor pressures of liquids range from 0.001 to 760 torr (mm'Hg), with solids
ranging down to 10 torr.l$J Vapor pressure is an important determinant
of the rate of vaporization of a chemical, but other factors, including
temperature and wind speed, degree of adsorption, water solubility, and soil
conditions, are also important. Vapor pressure is most directly relevant to
exposure pathways involving chemical releases to air from spills or
contaminated surface soils. The Henry's law constant, which combines vapor
pressure with solubility and molecular weight, is more appropriate for
estimating releases to air from contaminated water (e.g., surface water) and
should be used to evaluate chemicals for which this type of exposure pathway
is expected.
The organic carbon partition coefficient (K ) is a measure of
relative sorption potential for organic chemicals and is a significant
environmental fate determinant for all exposure pathways, especially aqueous
pathways. K indicates the tendency of an organic chemical to be adsorbed
to soil.isj K is expressed as the ratio of the amount of chemical
12J R.E. Menzer and J.O. Nelson, "Water and Soil Pollutants," in J.
Doull, C.D. Klaassen, and M.D. Amdur, Toxicology (New York: MacMillan, 1980).
1JJ W.J. Lyman, "Solubility in Water," in Lyraan, et al., Handbook of
Chemical Property Estimation Methods (New York: McGraw-Hill, 1982).
lfcj H.M. Jaber, W.R. Mabey, A.T. Liu, T.W. Chow, H.C. Johnson, T. Mill,
R.T. Padall, and J.S. Winterle, Data Acquisition for Environmental Transport
and Fate Screening (Washington, D.C.: Office of Health Assessment, U.S.
Environmental Protection Agency, 1984).
IJJ C.F. Grain, "Vapor Pressure," in Lyman, et al., Handbook of Chemical
Property Estimation Methods (New York: McGraw-Hill, 1982).
lij W.J. Lyman, "Adsorption Coefficient for Soils and Sediments," in
Lyman, et al., Handbook of Chemical Property Estimation Methods (New York:
McGraw-Hill, 1982).
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OSWER Directive 9483.00-2
2-7
adsorbed per unit weight of soil organic carbon content to the chemical
concentration in solution at equilibrium. Therefore:
K = mg adsorbed/kg organic carbon
oc
mg dissolved/liter solution
The normal range of K values is from 1 to 107, with higher values
indicating greater sorption potential.17-1 Many other partition coefficients
exist (e.g., organic matter coefficient (K ), soil/water distribution
oro
coefficient (K,)), but K was selected for use as an indicator of soil
d oc
adsorption because it is chemical-specific and for organics- is directly
related to soil and sediment sorption, both of which are significant chemical
fate processes at many sites. For inorganics, some other parameter such as
the distribution coefficient for a specific soil type (K.) or the maximum
exchangeable mass may be a better measure of relative adsorption potential.
The significance and interpretation of K .varies with different exposure
pathways. For ground water, low K values indicate that sorption of the
OC
chemical to the soil organic matter is not a fate-controlling process and,
therefore, faster leaching from the waste source into an aquifer and
relatively rapid transport through the aquifer (i.e., limited retardation of
the chemical) occurs. K is directly proportional to the retardation
OC
factor, which is used-in many ground-water transport models. Therefore, high
mobility (low K ) chemicals generally would be of more concern than low
mobility (high K ) chemicals. The effectiveness of using K to predict
mobility is dependent on the fraction of organic carbon in the soil in contact
with the chemical.
For surface water pathways, K also has several significant implica-
tions. A high K indicates tight bonding of a chemical to sediments high
in organic carbon, which means that less of the chemical will be dissolved in
site runoff, but also implies that runoff of contaminated particles may occur
over a longer time period. At some sites, direct recharge of surface water by
ground water is important; in these situations, because of ground-water
mobility considerations, chemicals with high K values are of relatively
lower concern. The K value also indicates the relative amount of sediment
oc
adsorption in surface waters.
The octanol-water partition coefficient, K , is often used to
ow
estimate the extent to which a chemical will partition from water into
lipid-containing parts of organisms (e.g., animal fat) and thereby
bioaccumulate. K is often expressed in log units (i.e., log K ).
17J W.J. Lyman, "Adsorption Coefficient for Soils and Sediments," in
Lyman, et al., Handbook of Chemical Property Estimation Methods (New York:
McGraw-Hill, 1982)..
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OSWER Directive 9483.00-2
2-8
Compounds with a low log K (e.g., less than 1) tend to have small
sediment/soil partition coefficients, and relatively high water solubilities.
A high log K indicates that the chemical will partition into the sediment
or soil, and have a low water solubility. Once a chemical enters surface
water, however, a high log K may be of great concern because it indicates
a tendency to bioaccumulate. If aquatic food chain pathways are possibly
significant, this implication of K should be considered.
Persistence is a measure of how long a chemical will- exist in a given
environmental medium, obviously a critical factor in assessing exposure
potential. Important removal processes are phase transfer-(e.g., water to
air, soil to water), chemical transformation (e.g., hydrolysis, photolysis),
and biological transformation (e.g., biodegradation). Available persistence
data are given in Exhibit C-2 as ranges of overall half-lives (i.e., due to
all removal processes) in ground water and surface water. If half-life values
from other sources are used, the applicant must'determine whether they
represent overall disappearance rates or whether they correspond to a specific
removal mechanism. The rate at which removal processes occur will depend on
the specific environmental conditions. The disappearance rate will act as a
measure of how quickly a chemical is removed from the environmental medium.
Half-lives of chemicals vary from seconds to thousands of years. Small
half-lives generally indicate a lower level of concern, although degradation
products may have a higher toxicity or environmental mobility than the
original chemical. The literature may be a potential source of degradation
product data; however, the applicability of these data to the variance
demonstration will depend on the degradation process that can be expected for
the site being analyzed.
Specific gravity is the ratio of the density of a substance to the
density of pure water. Consequently, if a substance is denser than water, its
specific gravity is greater than one, and the substance will tend to sink in
water. If the substance is less dense than water, it has a specific gravity
less than one, and the substance will float on water. The specific gravity of
a substance, therefore, is a measure of how the substance behaves when placed
in water. This principle can be applied to contaminants as they pass through
the unsaturated zone and come into contact with the ground-water table. A
contaminant with a specific gravity less than one will float on top of the
water table and, if it has a low solubility, will mix very little with the
ground water. If a contaminant has a specific gravity greater than one, it
will sink toward the bottom of an aquifer. A liquid contaminant with a
specific gravity of one will tend to mix with the ground water. Exhibit 2-2
illustrates the effect of specific gravity on the movement of contaminants in
ground water.
In a uniform geologic setting, the greater the specific gravity of the
contaminant is above one, the greater the downward migration of that
contaminant will be and the slower the contaminant will travel in relation to
the velocity of the ground-water flow. Generally, the majority of chemical
contaminants travel in the direction of ground-water flow at a velocity
somewhat less than that of the ground water. The prediction of contaminant
migration requires accurate knowledge of the specific gravity and solubility
of the contaminant solution.
-------
OSWER Oircetive 9483 00-:
Exhibit 2-2
TRANSPORT OF CONTAMINANTS WITH DIFFERENT SPECIFIC GRAVITIES
Travel of contaminant with same density
as water in the aquifer (I.e., a specific
gravity of one).
Source
Ground-Water
Row Direction
"7 I ) I I i i I I I I
b. Travel of contaminant that is
denser than water in the aquifer.
Source
Ground-Water
Row Direction
7 IT I
I I I 1 I
c. Travel of contaminant that is less
dense than water in the aquifer.
Source
Ground-Water
Flow Direction
d. Travel of contaminant that is denser
than water and sinks in the aquifer.
Source
Ground-Waie
Row Directio
iter Table
V
lilt
Source. R. Allan Freeze and John A. Cherry, Croundwaitr. (New Jersey Prentice-Hall, Inc . 19"9). p 3?c
-------
OSWER Directive 9483.00-2
2-10
Viscosity of a fluid is the property of resistance to relative motion
and shear deformation during flow. The more viscous the fluid, the greater
the shear stress and, thus, the resistance to flow. Viscosity is affected by
temperature; the higher the temperature, the lower the viscosity and the
easier it will be for a fluid to move through the pores in a medium. Water is
the primary viscosity standard. Hydrocarbon liquids such as hexane are less
viscous, while heavy lubrication oil is highly viscous. -The viscosity of a
contaminant will partially control the rate of movement or migration. More
viscous contaminants will not move as easily through porous media.
Consideration of contaminant viscosity, if it differs significantly from water
viscosity, in conjunction with other applicable chemical properties may be
necessary for prediction of contaminant migration.
The oxidation state of some metals (as determined by the number of
valence- or outershell-electrons) is affected by the oxidation-reduction
(redox) potential of ground or surface water or soils. While metals such as
sodium usually exhibit only one oxidation state (e.g., sodium +1), others,
such as chromium, manganese, iron, and copper (transition metals), have
multiple oxidation states.
Changes in the oxidation state of a metal may affect its relative
solubility or insolubility in water. A soluble metal species may become
insoluble and precipitate out of ground water, thus altering its transport or
migration with changes in the redox potential. A change in oxidation state
can also affect the toxicity of a contaminant. For example, chromium is the
most toxic, and mobile in an oxidation state of +6. Under acidic or reducing
conditions, chromium can change oxidation states from +6 to +3. The +3
chromium is less toxic and generally immobile in ground water because it will
readily combine with dissolved anionic species, such as hydroxide, and
precipitate to form insoluble compounds. This phenomenon is common to most
inorganics and to all transition metals (as listed above).
2.1.2 Toxicoiogical Properties
Toxicoiogical properties that indicate potential hazard to exposed
individuals include:
toxicity class (potential carcinogen or noncarcinogen);
EPA qualitative weight-of-evidence category (potential
carcinogens);
EPA severity-of-effect rating value (noncarcinogens); and
indicator chemical toxicity constant.
These properties have already been identified for most chemicals (see Appendix
C). On Worksheet 2-2 the applicant should record the toxicity class, EPA
rating value, and indicator chemical toxicity constant for each chemical
identified in Worksheet 2-1. These toxicological properties can be found in
Appendix C. The indicator chemical toxicity constants, which can be found in
Exhibits C-3 and C-5, should not be confused with the risk characterization
toxicity constants, which can be found in Exhibits C-4 and C-6 and are to be
used in Chapter 6 (Health Effects Evaluation). Each of these toxicological
properties is described below.
-------
WORKSHEET 2-2
INDICAIOK CHEMICAL IOXICI1Y INfOHMAIION
INS1KUCIIONS:
1. Record compounds from Worksheet 2-1, llien n:li:r in Exhibit C-3 and C-5 and note
whether they are classified as potential carcinogen (PC) or noncarcinogen (NC) or both.
2. Record the rating value (noncarc inocjens, txhilni C-5) or EPA category
(potential carcinogens. Exhibit C-'i) for each compound in each class.
If there are route-specific differences (i.<;.. oral or Inhalation), record both values.
3. Refer to Exhibits C-3 and C-5 and record the toxicity constant value associated with water.
faciIi ty ID:
Uatn:
Analyst:
Qua Ii ty Control:
Chemical
Acetoni trile
Toluene
Toxicologic Class
(I'C, NC)
Rating Value/EPA Category a/
NC
_NA_
7 (inhalat ion)
Water loxicity Constant
(
Arsenic
Te t rach 1 o roe thy 1 ene
re
NC
I'C
NC
A
9
1)2
7 (oral)
10 ( inha (at ion)
n.o/
16
.UH89
.0(196
. 0052
a/ Rating value is for seyerity-of-effect for iioncarc inocjens, range is l(low) to I0(hiyh); EPA category is a qualitative
weight-of-evidence designation for potential carcinogens; explanation of the categories is presented in Exhibit 2-2.
Information taken from Appendix C.
ASSUHI't IONS;
List all the major assumptions made in dtivolopiiuj Hie data for this worksheet:
-------
OSWER Directive 9483.00-2
2-12
Toxicity class for a chemical indicates whether the chemical is a
potential carcinogen and/or noncarcinogen. The designation of the class or
classes is based on experimental evidence, structure activity relationships,
and epidemiological evidence.
Exhibits C-3 and C-5 list potential carcinogens and noncarcinogens,
respectively. Consequently, an applicant must review both lists to identify
the toxicity class(es) for a particular chemical.
Generally, compounds either not listed in Appendix C or with insufficient
data for indicator scoring should be classified as unknown under toxicologic
class in Worksheet 2-2. These substances should be listed in the application
to provide an indication of the uncertainty associated with omitted chemicals
and to assist regional and headquarter's personnel in identifying data gaps.
If the applicant has reason to believe that these compounds may be significant
at his/her site, he/she may contact the Environmental Criteria and Assessment
Office (ECAO), U.S. EPA, 26 W. St. Clair Street, Cincinnati, Ohio 45268-, for
guidance in determining the toxicity class and estimating the necessary
toxicity constants.
EPA qualitative weight-of-evidence category indicates the quality and
quantity of data underlying a chemical's designation as a potential human
carcinogen. The categories of evidence for human carcinogenicity include
sufficient, limited, and inadequate. Exhibit D-2 (Appendix D) presents the
EPA qualitative weight-of-evidence categories for potential carcinogens.
Weights of evidence for specific chemicals are provided in Exhibit C-4
(Appendix C).
EPA rating value identifies the severity of effect for noncarcinogens.
The value ranges from 1 to 10, where one represents minor biochemical changes
and 10 represents death or pronounced life-shortening. The EPA rating values
for specific chemicals are presented in Exhibit C-5 (Appendix C). The effects
associated with each rating value are provided in Exhibit D-l (Appendix D).
Toxicity constants for indicator chemical selection (T values) are
derived for cwo types of toxic effects (carcinogenicity and other chronic
effects). Indicator chemical toxicity constants for noncarcinogens (Tn) are
derived from the minimum effective dose (MED) for chronic effects, a severity-
of-effect factor (i.e., EPA rating value), and standard factors for body
weight and oral intake (e.g., 70 kg body weight, 2 liters/day of drinking
water). Indicator chemical toxicity constants for potential carcinogens (Tc)
are based on the dose (i.e., effective dose) at which a 10 percent incremental
carcinogenic response is observed (ED1Q) ^d the same standard intake and
body weight factors used for the MED. Values for indicator chemical toxicity
constants for a number of compounds are given in Exhibits C-3 and C-5.
Appendix D describes in detail the methods used for calculating the toxicity
constants in Appendix C. The data base for this procedure is adopted from the
supporting documentation for the Superfund Reportable Quantities
rulemaking.lij
1§J EPA, ECAO. Summary Data Tables for Chronic Noncarcinogenic Effects,
1984. [Note: Prepared during Reportable Quantity adjustment process]; and
EPA, OHEA. Methodology for Evaluating Reportable Quantity Adjustments
Pursuant to CERCLA Section 102, External Review Draft, OHEA-C-073, 1986.
-------
OSWER Directive 9483.00-2
2-13
2.2 SELECTION OF INDICATOR CHEMICALS
The purpose of this section is to present a methodology to select
indicator chemicals. This procedure was adapted from the Superfund Public
Health Evaluation Manual.;ij The indicator chemical selection procedure
described here is designed to identify the "highest risk" chemicals at a site
so that the risk assessment is focused on the chemicals of greatest concern.
Two separate sets of indicator'chemicals will be selected: one for the human
health effects evaluation and another for the environmental impact
evaluation. The indicator chemical selection process is designed for tank
systems with large numbers of chemicals where consideration of all physical,
chemical, and concentration information at one time is too cumbersome. If
only a moderate number of chemicals are present within the 'tank system(s), all
toxicity, chemical, and physical factors may be considered simultaneously. In
general, if less than 10 to 15 chemicals are handled within the tank
system(s), this indicator chemical selection step is not necessary (i.e., all
the chemicals should be considered indicator chemicals). In such.cases, the
applicant should proceed to Section 2.3 and evaluate the potential release
volumes and chemical release masses for all of the chemicals handled within
the tank system(s).
For tank systems that contain a large number of chemical substances,
conducting a risk assessment that includes all the identified chemicals may be
unnecessary. In these cases, the risk-based variance can be based on selected
indicator chemicals that pose the greatest potential risk to human health and
the environment at or near a facility. -Such indicator chemicals must be
chosen carefully so that they represent the most toxic, highly concentrated,
mobile, and persistent chemicals stored and/or treated in the tank systems at
the site (i.e., the "highest risk" chemicals).
Two important factors for ranking chemicals in the indicator chemical
selection process are their measured concentrations within the tank systems
and their toxicities. Additional factors to be considered include physical
and chemical parameters related to environmental mobility and persistence.
If, after completing the procedures described in this section, any chemicals
considered to be potentially significant are not selected, professional
judgment should be used to include them. It is not intended that the
indicator chemical selection process exclude any chemical that may potentially
cause significant human or environmental harm. Rather, the intent of the'
process is to ensure that all chemicals that may potentially pose a
significant risk to human health and the environment are addressed and to
focus the risk assessment on the chemicals of primary concern,.
The procedure to select indicator chemicals consists of three steps. A
flowchart of these steps is presented in Exhibit 2-3. The procedures for
carrying out the three selection steps are described in the remainder of this
section." The initial list of chemicals presented in Worksheet 2-1 will be
shortened using additional factors to develop a final indicator list. In the
ISJ EPA, Superfund Public Health Evaluation Manual. Office of Emergency
and Remedial. Response, EPA 340/1-86/060, October 1986, pp. 19-34.
-------
OSWER Directive 94S3.0I
Exhibit 2-3
OVERVIEW OF PROCEDURE FOR
SELECTING INDICATOR CHEMICALS
SECTION 2.2.1
Record volumes and concentrations
from waste analysis data; determine
minimum, maximum and representative
values: and evaluate transport potential.
SECTION 2.2.2
Calculate indicator scores (IS)
for all chemicals.
SECTION 2.2.3
Select indicator chemicals based on
indicator score and additional factors.
-------
OSVER Directive 9483.00-2
2-15
examples on the worksheets accompanying this section, only four chemicals are
used. An applicant with four chemicals would not need to select a set of
indicator chemicals (all would be considered); however, for illustrative
purposes, we only present four.
2.2.1 Identification of Representative Chemical Concentrations
A chemical may exist at different concentrations in one or more tank
systems or components. For example, chloroform may be present in two
different tank systems for which the variance would apply. To facilitate the
risk assessment process, it may be helpful to summarize-these concentrations
with one concentration. Worksheet 2-3 illustrates a procedure for calculating
the overall concentration of a chemical based on the concentrations of the
chemical in different tank systems.
For each chemical, the applicant should list on Worksheet 2-3 the tank
systems where the chemical is stored or treated, the annual throughput", and _
chemical concentrations within the tank system. The chemical concentrations
should be based on a detailed chemical and physical analysis of the waste
contained in the tank systems.:8J To determine the representative chemical
concentration, it may be appropriate to use a geometric mean21-1 of all of
the samples as the most representative concentration, or it may be more
appropriate to choose a concentration that reflects a time trend occurring at
the site. The applicant should calculate the minimum, maximum, and
representative annual mass of the chemical handled by the tank system by
multiplying the' annual tank throughput by each concentration. The applicant
should then calculate the total annual throughput and minimum, maximum, and
representative annual mass of chemical by summing the annual throughputs and
masses, respectively. The overall minimum, maximum, and representative
chemical concentration within the tank systems is the ratio of the total
chemical mass to the total annual throughput of the tank systems containing
the chemical.
Worksheet 2-4 should be used to list all hazardous constituents handled in
the tank systems included in the variance application and handled in tank
systems chat were previously granted a variance. Worksheet 2-4 should also be
20J Most owners or operators who treat, store, or dispose of any
hazardous waste must obtain a detailed chemical and physical analysis of a
representative sample of the waste (40 CFR 264.13). Owners and operators
seeking a variance who are exempt from the waste analysis requirement must
conduct this analysis for the variance. Applicants may refer to the following
documents for guidance on analyzing the contents of their tanks: EPA, Test
Methods for Evaluating Solid Waste, SW-846, Office of Water and Waste
Management, 1982; or EPA, Methods of Chemical Analvsis of Water and Waste,
EPA-600/4-79-020, March 1979.
21J The geometric mean (antilog [In X^ + In X2 + ... + In X ]/n)
is considered to be more representative than an arithmetic mean for evaluating
environmental data. See: Robert B. Dean, "Use of Log-Normal Statistics in
Environmental Monitoring," in Chemistry in Water Use: Volume I, William J.
Cooper, ed. (Ann Arbor: Ann Arbor Science Publishers, Inc., 1981), pp.
245-258.
-------
WORKSHEET 2-3
CALCULAIION Ol OVERALL CHEMICAL CONCENTRATIONS IN TANK SYSTEMS
INSTRUCT IONS:
I. Identify the chemicals in the tank systems (usn one worksheet for each chemical).
2. Identify tank systems that contain each i:hi;mic«i I .
3. Identify annual throughput of each tank system in liters (to convert
from gallons to liters multiply by 3./8VO.
ti. Identify chemical concentrations (minimum, maximum, representative)
in each tank system.
5. lor ea'ch tank system, calculate the annual mass of chemical handled hy the tank
(the annual mass equals the product of tho annual throughput and concentration,
divided by 1,000,000 to convert to kilograms.)
6. Calculate total annual throughput of all tanks and total annual mass of chemical
handled in all tank systems.
7. Calculate the overall chemical concentration within the tank systems (divide total
annual mass of chemical by total annual throughput and multiply by 1,000,000 to
convert to milligrams).
ChemicaI:
Toluene
Annua
Chemical Concentration
In Tank System (rog/j)
fan i I i ty II):
Ua to:
Analyst:
Qua Ii ty Control:
Annual Mass of Chemical
Handled in Tank System (kg)
Tank System 10
A-l
A-2
A- 3
Throughput ( 1 i ters)
75.708
283.905
1 5 1 . H 1 6
Minimum Maximum
.7 6.0
.9 10.0
1.0 11.0
Representative
1.0
6.0
6.0
Minimum
.0530
.255
.151
Maximum
2.8.19
1.-.666
Representative
.303
1.703
.908
Total:
511.U29
.1)60
'1.959
2.913
Overall chemical concentration in tank systems: ,9
9.7
5,7
ASSUMPTIONS:
List all major assumptions made in developing the data for this worksheet:
-------
WORKSHEET 2-
-------
OSWER Directive 9483.00-2
2-18
used to summarize the chemical concentration information developed in
Worksheet 2-3. In addition, the applicant should record on this worksheet the
K value, log K value, and toxicity constant for each chemical from
oc ow
Worksheet 2-2. The applicant should indicate on Worksheet 2-4 the basis for
the representative concentration chosen and note any assumptions or additional
information required to use this information. If there are concerns about use
of these concentrations, they should be noted. For example, if a highly toxic
chemical will be present- in the tank in the future, it should be included. If
a chemical is considered sufficiently important, it may be chosen as an
indicator chemical regardless of its concentration.
2.2.2 Calculation of Indicator Scores for all Chemicals
This section is divided into two subsections. The first describes the
process for calculating the indicator scores that will be used in selecting
the chemicals tp be considered for the human health effects evaluation
(health-based indicator scores, or ISH). The second subsection presents the
procedure for calculating indicator scores that will be used in choosing the
chemicals to be considered in the environmental impact evaluation
(environmental quality-based indicator scores, or ISE).
Health-Based Indicator Scores. The following algorithm is used to
determine the health-based indicator score for each chemical within the tank
systems:
where
ISH. = health-based indicator score for chemical i
i
(dimensionless),
C. = overall concentration of chemical i within the tank
systems at the facility based on waste analysis data
(units must be mg/1 in water), and
T. = an indicator chemical toxicity constant for chemical
i (units are the inverse of above concentration units).
Concentration values used in this equation for a given chemical should be
representative of all available data. Indicator chemical toxicity constant
units are the inverse of their respective concentration units so that
indicator scores (C»T) will always be dimensionless. Essentially, the
indicator score is a ratio between measured concentration and a toxicity-based
concentration benchmark that is used to rank the chemicals. The use of these
toxicity constants for selection of indicator chemicals within hazardous waste
tank systems will be reconsidered if additional toxicological information
becomes available for ranking the toxicity of a large number of chemicals.
The next task is to compare the ISH values of the various chemicals.
Because of probable differences in dose-response mechanisms (non-threshold vs.
threshold), potential carcinogens (PCs) and noncarcinogens (NCs) are scored
and compared independently. Indicator scores for carcinogens and
noncarcinogens are not on comparable scales and should never be compared.
-------
OSWER Directive 9483.00-2
2-19
The applicant should list all potential carcinogens on Worksheet 2-5 and all
noncarcinogens on Worksheet 2-6. The applicant should then calculate C times
T (i.e., OT) for each chemical and the associated overall minimum, maximum,
and representative-concentrations. The chemicals on Worksheets 2-5 and 2-6
should be ranked separately on the basis of the indicator scores. If a
chemical is designated as both a PC and NC, the indicator scoring procedures
should be completed for it in both toxicity classes.
Environmental Quality-Based Indicator Scores. A slightly different
equation is required to calculate environmental quality-based indicator scores:
ISEi =
where
ISE. = the environmental quality-based indicator score
for chemical i (dimensionless),
C. = overall concentrations of chemical i within the
tank systems at the facility based on waste analysis
data (units in mg/1), and
Q. = freshwater chronic water quality criterion for
chemical i (units in mg/,1).
The same overall concentrations that were used to calculate health-based
'indicator scores should be used here. The freshwater chronic water quality
criteria (Q) for a number of chemicals are provided in Exhibit 7-2. On
Worksheet 2-7, the applicant should list all chemicals contained in the tank
systems. For each chemical the applicant should calculate the ratio of the
overall minimum, maximum,and representative concentrations to the freshwater
chronic water quality criterion for the chemical. If no criterion is
available for the chemical, the applicants should state "data not available."
Based on the indicator scores, the applicant should rank che chemicals from
highest to lowest environmental quality-based indicator score.
2.2.3 Selection of Final Indicator Chemicals
The applicant should use Worksheet 2-8 to prepare an initial list of
indicator chemicals to be considered for use in the human health effects
evaluation and Worksheet 2-9 to prepare an initial list of indicator chemicals
to potentially be used for the the environmental impact evaluation. The final
lists of indicator chemicals (one for the health effects evaluation and one
for the environmental impact evaluation) will be selected from these initial
lists of indicator chemicals. In most cases the initial list (and,
subsequently, the final selection) should be based on representative
concentrations, although indicator scores based on minimum or maximum
concentrations may be used to modify the selection.
On Worksheet 2-8 the applicant should record, in rank order according to
the health-based indicator score values, the top-scoring 15 to 20 chemicals
from both Worksheet 2-5 (potential carcinogenic effects) and Worksheet 2-6
(noncarcinogenic effects). This initial list of indicator chemicals on
Worksheet 2-8 should then be compared to the chemicals identified with either
-------
WORKSHEET 2-5
fOR INDICATOR CHCHICAL SELECTION:
CALCULATION Of INDICATOR SCORE VALUES AND TENTATIVE RANK FOR CARCINOGENIC EFFECTS
INSTRUCTIONS;
1. List all of the chemicals to be considered as potential carcinogens. Facility ID:
2. CaIculate 'overaI I concentration times toxiciiy (CT) values using the information From Date:
Worksheets 2-1 and 2-2. Calculate a CT based on the overall minimum, maximum, and
representative concentrations. " Analyst:
3. Rank the compounds based on their minimum, maximum, and representative indicator Quality Control:
score values. Also, enter their El'A woight-of-evidonce category in the Final
column.
Indicator Scoie
Chenica 1
Arsenic
Tetrachloroethylene .
Minimum
O.O'lO?
0
Ma x i mum
1.87
0.5936
Va 1 in;
Represent a t i ve
0.305J
0.028U
Maximum
1
2
Tentative
Mini mum
1
2
Rank
Reprcsenta t ivo
1
2
Weight of
Evidence
A
B2
ASSUMPTIONS:
List all major assumptions made in developing the data For this worksheet:
-------
WORKSHEET 2-6
SUM INC. (OR I NO ICAI OR CHEMICAL St LECTION:
CALCULAIION OF INI) 1C AI OK SCOItl VALUES AND IENIA1IVE RANK FOR NONCARC IMOGEN 1C EFFECTS
INSIRUCTIQNS:
1. List all of the chemicals to bo constricted lor noncarcinogenic effects.
2. Calculate overall concentration times toxtctiy (Cl ) values using the information
from Worksheets 2-1 and 2-2. Calculate Cl values based on the overall minimum,
maximum, and representative concentrations.
3. Rank the compounds based on their minimum, m.iximum, and representative
indicator score values. Also enter the seventy-of-effects rating value(s)
Jn the final column.
FaciIi ty ID:
Date:
Analyst:
Qua Ii ty Control:
Indicator Jjcojjs ynIuc
Chemical
Arsenic
Tetrachloroethylene
Acetonitri le
Toluene
Minimum Maximum
0.18 8.28
0 0.6't'i5
NA NA
0.00'l7 0.0501)
Tentative Rank
Rat ing
Va I uo t s 1
Representative Minimum
0.135 I
0.0308 3
NA
0.0296 2
Maximum
1
2
_
3
Representative Oral Inhalatioi
1 -9
2 7 TO
3 7 7
ASSUMPTIONS;
List all major, assumptions made in developing the data Tor this worksheet:
-------
WORKSIIEEI 2-7
SCOKINC I OR I NO ICAI OH CHEMICAL SllCCIION:
CALCUIAIION OF I Nil ICAI OK SCOKL VALUES ANU 1ENIATIVE HANK FOR ENVIRONMENTAL EFFECTS
INSTRUCTIONS;
1. List all of the chemicals to be considered for environmental effects. . Facility II):
2. Calculate indicator scores by dividing overall concentration by fresh water chronic water Date:
quality criteria using the information from Worksheets 2-1 and 2-2. Calculate
water quality indicator score values based on overall minimum, maximum, and representative Analyst:
concentrations.
Qua Ii ty Control:
3. Rank the compounds based on their minimum, maximum, and representative
indicator score values.
I nil i c.i tor ho ore Value Tentative Rank
Chemical Minimum Maximum Representative Minimum Maximum Representative
Arsenic LOE-ii ^QQZH .OOO'I < 2 2,
Tetrachloroethvlene 0 0.6796 O.OQ36 __ 2 1 1_
Ace ton i tri le - - r _i ~
Tolucne
ASSUMPTIONS;
List all major assumptions made in developing the data for this worksheet:
-------
WORKSHEET 2-8
SCORING I OH I NO ICAI Oil CHIMICAL StJfCIION fOK HUMAN HEALTH EFFECTS EVALUATION:
EVALUAIION Ul IXI'OSUnC FACTORS AND FINAL CHEMICAL SELECTION
INSTRUCT IONS:
1. List the top 15 to 20 PC and NC chemicals based on health-based- indicator score (ISII)
values, giving their ISfl values and their ranking (use additional sheets).
2. Refer to Worksheet 2-1 and record each chemical's solubility, vapor pressure,
Henry's law constant, Koc, and ha If-lives in ground water, surface water, soil, and air.
3. Select the final indicator chemicals. Use your Judgment -- if a compound has
a high water solubility and a long ha If-life, yet is ranked lower than a compound
with minimal water solubility and a short ha If-life, you may wish to move it up in
the ranking (refer to Section 2.2.3 for additional guidance on the final selection).
14. Document any changes in ranking made because ol exposure factors.
5. In the last column indicate with a "t" those chemicals that have been selected as
indicator chemicals (1C).
faciIi ty 10:
Oate:
Analyst:
Qua Ii ty Control:
Chemica 1
Arsenic
Tetrachloroethvlene
Ace ton i tri le
To luerie
a/ Water Vapor Henry's Law
ISII Values ftankimt Solubility Pressure Constant Half-Life (Oavs)
PC NC PC NC (mg/1) (mm llg) ( atm-m3/mole) Koc ' GW SW Soil Air 1C b/
0. 305 0. 135 1 1 NA 0 NA - PERS PERS ITRS 5 +
0.028 0,031 2 2 150 178 0.026 36'» NA 1-30 NA l|7 +
NA -__ NA - 1.000.000 7't ,00004. 2.2 NA 7 NA 390 +
NA 0,030 NA 3 535 28,1 0.0061 3.00 _NA ,17 NA 63 *
a/ Based on overall representative concentrations.
b/ Because only four chemicals are used in this example, all four are chosen as indicator chemicals.
more chemicals, the top 10 to 15 chemicals would iiave been selected as indicator chemicals.
ASSUMPTIONS:
List all major assumptions made in the development of data for this worksheet:
If there had been 15 or
-------
OSWER Directive 9483.00-2
2-24
an H (or H*) or an L (or L*) on Worksheet 2-1. H indicates one of 10
chemicals with the highest K values (H* refers to K ), and L indicates
oc ow
one of 10 chemicals with the lowest K values (L* refers to K ). If an
oc ow
important exposure scenario at the site (see Chapter 5) involves consumption
of contaminated fish and none of the 10 chemicals designated with an H* (i.e.,
a high K value) made it onto the initial indicator list on Worksheet 2-8,
ow
the applicant should consider placing one or more of them onto that list. If
exposure via ground-water contamination is a concern and none of the 10
chemicals designated with an L (i.e., a low K ) made it onto the initial
indicator list on Worksheet 2-8, the applicant should consider enlarging the
initial indicator list to include one or more of these chemicals. Some
chemicals may not have b
-------
WORKSHEET 2-9
SCORING fOR INOICAIOR CHIMICAL SELECT ION fOR ENVIRONMENTAL IMPACT EVALUATION:
EVALUATION 01 IXI'OSURE FACTORS AND FINAL CHEMICAL SELECTION
INSTRUCTIONS:
1. List the top 13 to 20 chemicals according 10 environmental quality-based indicator
score (ISC) values, giving tlioir ISE values ami thoir ranking. Also list chemicals
that could not bo scored.
2. Refer to Worksheet 2-1 and record each chemical's solubility, vapor pressure,
Henry's law constant, Koc, and hair-lives in ground water (GW). surface water (SW),
soi I , and a i r.
3. Select the final indicator chemicals based on the guidelines presented in Section 2.2.3.
Use your judgment -- if a compound has a high water solubility and a long ha If- life,
yet is ranked lower than a compound with minimal water solubility and a short half-
life, you may wish to move it up in the ranking.
Faci I i ty II):
Date:
Analyst:
Qua Ii ty Control:
-------
OSWER Directive 9483.00-2
2-26
Henry's law constant, organic carbon partition coefficient (KOC).22J and
persistence in various media. Extremes of any of these factors for a chemical
found in a tank system may produce a high future exposure potential and may
warrant inclusion of the chemical in the final list of indicator chemicals
despite a low indicator score value. Values for these factors were specified
in Worksheet 2-1. The applicant should record appropriate values for the
initial indicator chemicals on Worksheet 2-7 for the human health effects
evaluation list and on Worksheet 2-9 for the environmental impact evaluation
list.
Clearly, other chemical properties could affect exposures and risks at a
specific site. 'However, to limit the amount of data to be collected and
considered, the characterization of the physical and chemical properties of
the chemicals focuses on the five properties listed above. These properties
are important, but not exclusive, determinants of environmental transport and
fate (e.g., density and viscosity are additional important properties). Some
of the properties have different implications for different exposure
pathways. As a result, consideration of the potential exposure pathways at a
site is necessary when applying physical/chemical factors in the selection
process. Refer to Section 2.1 for a brief description of the relevance of
each property to potential chemical release, transport, and fate.
Using the information provided below and the discussion in Sections 2.1
and 2.2 as guidance, the applicant should make the final selection of 10 to 15
indicator chemicals for each list. Starting with the initial chemical lists
compiled in Worksheets 2-8 and 2-9, the applicant should consider indicator
score values and relevant additional factors in the final selection process.
The applicant should indicate on Worksheets 2-8 and 2-9 final selections and
the rationale for each. If toxic organics and inorganics are both present in
the tank systems, at least one of each should be included on both of the final
lists of indicator chemicals. Chemicals on the preliminary indicators list
with sufficient evidence of human carcinogenicity (EPA Group A) or with
limited human evidence and sufficient animal evidence (EPA Group Bl) should
generally be selected as final indicators for the human health effects
evaluation (Worksheet 2-8), unless there are convincing reasons to do
otherwise, such as if a chemical has a relatively low concentration and
indicator score compared to other chemicals. For chemicals with similar ISH
values, those with a stronger weight-of-evidence should usually be selected.
On Worksheet 2-9, chemicals with the highest log Kow values should be included
in the final list, since bioaccumulation is a significant environmental impact.
By following the procedures described in this chapter, the applicant
should have selected a subset of the chemicals present in the tank systems to
22J As discussed previously (see Section 2.1), a chemical's K is
being used as an estimator of environmental mobility. K is considered to
account for the possibility of substances leaching out of the soil and being
introduced into surface and ground water. In general, chemicals with low
K values will tend to be leachable from soil and mobile in ground water.
oc
Also, chemicals with high K values tend to have correspondingly high
bioconcentration factors.
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OSWER Directive 9483.00-2
2-27
serve as indicator chemicals for the human health effects evaluation and the
environmental impact evaluation. The procedure has been structured to favor
the selection of those chemicals that pose the greatest potential risks and,
therefore, should serve as indicator chemicals. There are many components of
the selection procedure that require individual judgment. Care must be taken
to apply the general principles set forth in each step in a consistent manner
so that the final scores are comparable. The scores developed here are used
only for relative ranking and have no meaning outside the context of this
procedure. They should not be considered as a quantitative measure of a
chemical's toxicity or exposure potential.
2.3 POTENTIAL WORST-CASE RELEASE VOLUMES AND INDICATOR
CHEMICAL RELEASE MASSES
For each tank system component for which a variance is being sought, the
applicant must assume a release incident and corresponding release volume to
be used in assessing the potential risks to human health and the environment.
This section recommends specific worst-case release volumes for different tank
system components and describes how they should be used to calculate release
masses for the indicator chemicals. The transport of these release masses can
then be modeled and exposure point concentrations of the indicator chemicals
can be calculated (see Chapter 5). Subsection 2.3.1 discusses the methodology
for determining worst-case potential release volumes and Subsection 2.3.2
discusses the methodology for calculating chemical release masses.
2.3.1 Determination of Worst-Case Potential Release Volumes
When applying for a, variance, the applicant must use reasonable worst-case
potential release volumes associated with the tank systems or tank system
components for which a variance is being sought. Releases should be assumed
to occur over a 20-year time horizon, which is intended to simulate the
remaining operating life of the tank system. Although 20 years may
overestimate the remaining operating life of a tank system component in some
instances, estimates must be conservative in order to demonstrate no potential
hazard to human health and the environment. In situations where the applicant
can demonstrate to che Regional Administrator that the tank is going to
operate for less than 20 years, this shorter time horizon may be used. The
annual series of releases is termed a release volume profile, and is
illustrated in Exhibit 2-4 for tank system components in contact with the soil
(steady-state releases), and aboveground tanks (catastrophic releases).
The worst-case potential release volumes for a particular tank system
component (i.e., a tank or pipe) basically depend on whether the tank system
component can be visually inspected on all surfaces for leaks. Because
underground, inground, and onground tank systems have components that are in
contact with the soil, complete external visual inspection is not possible.
Consequently, such tank system components can conceivably leak (e.g., due to a
corrosion hole or seam failure) some percentage of their throughput for long
periods of time without the leak being detected. For underground, inground,
and onground tank system components, the applicant should therefore assume
that 25 percent of the annual throughput for a component could leak annually.
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OSWER Directive 9483.(
Exhibit 2-4
HYPOTHETICAL RELEASE VOLUME PROFILES
Steadv-State:
Volume
(m3)
20
Time (year)
Catastrophic:
Volume
20
Time (year)
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OSWER Directive 9483.00-2
2-29
The 25 percent cut off is based on professional judgment and the assumption
that a tank owner/operator does not suspect a tank leak unless the tank is
less than 75 percent full at the time the tank is emptied.
Aboveground tank system components, unlike underground, inground, and
onground components, can be visually inspected on all surfaces (daily visual
inspections are required by the regulations (40 CFR 264.195(b) (51 Federal
Register 25476, July 14, 1936))) and, therefore, are not likely to leak over
a long period of time. Thus, the worst-case potential release volume for an
aboveground tank system component is typically a. release, that occurs between
daily inspections. For an aboveground tank, the applicant should assume that
the full tank volume is released due to a catastrophic failure in the first
year of the modeled time horizon. The probability of a catastrophic release
is sufficiently small that it would be unrealistic to assume more than one
during the operating life of the tank. For aboveground ancillary equipment,
such as piping and pumps, the applicant should assume that a volume equivalent
to the maximum daily throughput is-released annually for the operating life of
the tank system. The potential for leaks from aboveground ancillary equipment
is sufficiently high to justify the need to consider releases on an annual
basis.
The variance applicant should not use release volumes smaller than those
presented here. The release volumes that should be used for individual
components are summarized below:
Component Location
Component
Release Volume
Underground, inground,
onground
Aboveground
Aboveground
All components
Tank
Ancillary equipment
25 percent of the annual
tank system throughput
annually for 20 years
Tank capacity released in
model year one
Maximum daily throughput
annually for 20 years
To obtain the total annual release volumes (i.e., release profile) for a tank
system, the release volumes for the individual components of the system must,
in most cases, be summed. An exception to this rule is for components in a
tank system that are located underground, inground, or onground. The release
volumes for all of these components in a tank system should not be added;
i.e., the total release volume for all underground, inground, and onground
components in a tank system should be assumed to be 25 percent of the annual
throughput annually. By not adding release volumes for these components,
multiple counting of release volumes is avoided. For example, consider a tank
system that consists of an aboveground tank of 5,000 gallons, fed by a run of
aboveground piping, and connected to an underground tank of 5,000 gallons by
underground piping. The maximum daily throughput for the aboveground piping
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OSWER Directive 9483.00-2
2-30
is 100 gallons and the annual throughput for the tank system is 25,000
gallons. For the aboveground piping, the release volume is 100 gallons per
year. For the aboveground tank, the release volume is 5,000 gallons in the
first year. For the underground piping and the underground tank the total
release volume is 6,250 gallons (.25 x 25,000) annually. For the whole tank
system 11,350 gallons are released in the first year (100 + 5,000 + 6,250),
and 6,350 gallons (100 + 6,250) are released annually thereafter.
The applicant should .complete Worksheet 2-10 in developing the release
volume profiles. On this worksheet, the applicant should list each tank
system and the tank system components for which a variance is being sought or
for which a variance was previously granted. For each component, the tank
volume, annual throughput, and maximum daily throughput sh'ould be provided
when applicable (e.g., tank volume does not apply to piping). For each
component, the annual release volumes should then be determined according to
the guidelines stated at the beginning of this section. Finally, the
applicant should sura the- release volumes1 for the components and record the
total release volumes for each tank system. Note that separate worksheets
should be used for different tank system clusters, if it is necessary to
cluster tank systems for modeling purposes.*JJ
2.3.2 Calculation of Indicator Chemical Release Masses
The identification of indicator chemicals and corresponding indicator
chemical concentrations (i.e., minimum, maximum, and representative) for each
tank system was discussed in Section 2.2 (the chemicals and concentrations
should be listed in Worksheet 2-3). This information must be combined with
the release volume profiles to obtain a release mass profile for each
indicator chemical. The applicant should use Worksheets 2-11, 2-12, and 2-13,
for the minimum, maximum, and representative indicator chemical concentrations,
respectively, to develop the indicator chemical release mass profiles. On
these worksheets, the applicant should list the indicator chemical, the tank
systems that contain the indicator chemical, the corresponding indicator
chemical concentrations (see Worksheet 2-3), and the corresponding release
volumes from chemicals Worksheet 2-10. The applicant should multiply the
indicator chemical concentrations by the release volume profile to obtain the
indicator chemical release mass profile for each tank system. The applicant
should then add the indicator chemical release mass profiles for each tank
system to obtain the total release mass profile for the indicator chemical.
If tank systems were clustered when assessing release volume profiles, the
same clusters should be maintained for determining release mass profiles. The
applicant must exercise care when specifying indicator chemical concentrations
J1J In some situations, tank systems may be physically separated by
relatively large distances such that releases from them would have different
exposure points, or it would not be realistic to model the transport of the
summed tank releases to the same exposure point. In such a situation, tank
systems should be clustered into groups in which the tanks are close enough
together to allow for realistic modeling of the transport of releases to
exposure points. A space is provided on the worksheet to identify the tank
system cluster, if necessary.
-------
WORKSIILET 2-10
voi mil ntofiLES ASSOCIATED wuii EACH TANK SYSTEM
JNSIHUCMONS:
1. List eacli tank system, its components I'cir which a variance is being soiujhl or
for which a variance was previously granted. tin; locations of the components
(i.e., aboveground, ong round, inground, underground), the tank volume, annual
throughput (not necessary Tor aboveground components), and maximum daily
throughput (only necessary for abovcgruund ancillary equipment).
2. Fill in the annual release volumes Tor the components according to the rules
specified in the text.
3. Tor each tank system, sum the release volumes of the components and record the result.
Note, however, that release volumes Tor iimlcnj round, inground, and ongroiintl components
in the same tank system should not be added. Only the release volumes from one of
these components should be counted in the total to avoid double counting.
facility ID:
Cluster:
Ua to:
Analyst:
Qua Ii ty Control:
Tank System
Tank System Component
A-l tank
pipe
A-2 tank
pipe
A-3 tank
pipe
pump
Component lank Volume
location (gallons)
underq round 5.000
underground n.a.
ong round 25.OOO
onq round n.a.
aboveq round 1 0 . OOP
aboveq round n.a.
aboveq round n.a.
Annual Throughput
(ga 1 Ions)
20.000
20.000
75.000
75.000
MO. 000
MO. 000
MO. 000
Maximum Da i ly
Throughput
(gal Ions)
n.a.
n.a.
Total
n.a.
n.a.
Total
n.a.
175
175
Tota I
Annual Id: lease Volume (qa lions)
Year 1 Years 2-20 (per year)
5 . OOO 5 , 000
_5^ooo _j,uooo
5.^000 5_, 000
18.75" 18.750
18.750 18.750
18.750 18.750
10.000 0
175 175
175 175
10. 35<> 350
.
Total
-------
WORKSHEET 2-11
RELEASE MASS PROM I fS ASSOCIAIU) WlIII EACH INDICATOR CHEMICAL: MINIMUM CONCEN1RATION
INSTRUCTIONS:
1. Eill out a separate worksheet for each indicator chemical.
2. Identify the tank system(s) that contain the indicator chemical.
3. List the minimum concentration within the lank systems from Worksheet 2-3.
ij. List the corresponding annual release volumes from Worksheet 2-8 Tor each
tank system.
5. Calculate for the indicator chemical the mass iclcased (in kilograms) Tor
each tank system (annual mass released equals the annual rqlcase volume
(in gallons) multiplied by 3.785M to convert to liters, multiplied by the
-6
minimum concentration (in mg/liter), multiplied by 10 to convert to
kilograms).
6. Calculate the total chemical mass released by summing the masses Tor the
individual tank systems.
FaciIity ID:
Cluster:
Date:
Analyst:
Qua Ii ty Control:
Indicator Chemical: Toluene
Tank Systen
Mini mum
Concentration (mg/liter)
A-l
A-2
.9
A-3
I.Q
Annual Volume Released
Year 1 Years 2-20 (per year)
5.000 5.000
18.750 18.750
10.350 350
Annual Mass Released (
Year T Years 2-20 (per
0.0132 0.0132
0.0639 0.0639
0.0392 ' ' 0.0013
kol
year)
TOTAL
0.1163 0.078'l
-------
WORKSHEET 2-12
RELEASE MASS PROFILES ASSOCIATED WITH EACH INDICATOR CHEMICAL: MAXIMUM CONCENTRATION
INSTRUCTIONS:
1. Fill out a separate worksheet for each indicator chemical.
2. Identify the tank system(s) that contain the indicator chemical.
3. List the maximum concentration within the tank systems from Worksheet 2-3.
<4. List the corresponding annual release volumes from Worksheet 2-8 for each
tank system.
5. Calculate for the indicator chemical the mass released (in kilograms) for
each tank system (annual mass released equals the annual release volume
(in gallons) multiplied by 3.785'4 to convert to liters, multiplied by the
-6
maximum concentration (in ing/liter), multiplied by 10 to convert to
ki tog rams).
6. Calculate the total chemical mass released by summing the masses for the
individual tank systems.
Facility ID:
Cluster:
Date:
Analyst:
Qua Iity Control:
Indicator Chemical: Toluene
Tank System
Maximum
Concentration (mg/liter)
Annual Volume Released (gallons)
Year 1 Years 2-20 (per year)
Annual Mass Released (kg)
Year 1
Years 2-20 (per year)
A-I
A-2
A-3
6.0
IQ.O
II.0
5.000
18.730
I0.33Q
3.000
18.730
330
0.I 136
0.7098
0.<43IO
Q.1136
0.7098
0.0416
TOTAL
I.251T
0.8630
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WORKSHEET 2-13
RELEASE MASS PROFILES ASSOCIAILO WITH EACH INDICATOR CHEMICAL: REPRESENTATIVE CONCENTRATION
INSTRUCTIONS:
1. Fill out a separate worksheet for each indicator chemical.
2. Identify the tank system(s) that contain the indicator chemical.
3. List the representative concentration within the lank systems from
Worksheet 2-3.
14. List the corresponding annual release volume:, from Worksheet 2-6 for each
tank system.
FaciIity 10:
Cluster:
Date:
Analyst:
Qua Iity Control:
5. Calculate for the Indicator chemical the mass released (in kilograms) Tor
each tank system (annual mass released oijunIs the annual release volume
(in gallons) multiplied by 3.7854 to convert to liters, multiplied by the
-6
representative bound concentration (in mg/liter), multiplied by 10 to convert to kilograms).
6. Calculate the total chemical mass released by summing the masses for the individual tank systems.
Indicator Chemical: Toluene
Representative Annual Volume Released (gal Iops)
Tank System Concentration (nig/liter) Year 1 Years 2-20 (per year)
Annual Mnss Released (kg)
Year 1 Years 2-20 (per year)
A-1
A-2
A-3
H.Q
6.0
18.750
10.330
3,000
'8.750
330
0.073?
O.H239
0.2331
0,0737
,0^252.
0.0079
TOTAL
0.7367
>.3Q93
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OSWER Directive'9483.00-2
2-35
for treatment tank systems in which the chemical concentrations differ among
tanks in a series. In such cases, the applicant must use the indicator
chemical concentration at the earliest point in the treatment system (i.e.,
inflow to the first tank) for which a variance is being sought.
A simple example may be helpful to illustrate the procedure. Consider a
facility with a 5,000 gallon aboveground tank and a 10,000 gallon underground
tank, both of which are filled and emptied four times a year (resulting in
annual throughputs of 20,000 gallons and 40,000 gallons, respectively). The
indicator chemical for the aboveground tank is benzene at a concentration of 5
mg/1. The indicator chemical for the underground tank is also benzene at a
concentration of 7 mg/1. The release volume profile for the aboveground tank
consists of 5000 gallons (18,927 liters) released in year one. The release
volume profile for the underground tank is 10,000 gallons (37,854 liters) per
year for 20 years. For benzene, the release mass profile for the aboveground
tank is (5 mg/l)(18,927 liters)(l kg/10* mg) = 0.0946 kg in year one, while
for the underground tank it is (7 mg/1)(37,854 liters)(l kg/10* mg) = 0.265
kg annually for 20 years. ' The sum of the two release mass profiles for
benzene is 0.0946 + 0.265 = 0.3614 kg of benzene released in the first year
and 0.265 kg of benzene released annually for 19 years thereafter. The
release mass profile for the indicator chemical benzene is illustrated in
Exhibit 2-5.
The release mass profiles developed for each indicator chemical should be
used in modeling the transport of the indicator chemicals and the calculation
of concentrations at exposure points. These steps are discussed in Chapter 5
of this technical resource document.
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OSWER Directive 9483.00-:
Exhibit 2-5
HYPOTHETICAL RELEASE MASS PROFILE FOR BENZENE
Mass Released
(kg)
0.3614
0.265
10
15
20
Time (year)
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OSWER Directive 9483.00-2
CHAPTER 3
HYDROGEOLOGIC CHARACTERIZATION
As stated in the revised hazardous waste tank regulations, the Regional
Administrator will consider the potential adverse effects on ground water,
surface water, and land quality, taking into account the hydrogeologic
characteristics of the facility and surrounding land in deciding whether to
grant a variance from the requirements of secondary containment.IJ This
chapter is intended to assis't owners/operators in identifying relevant
geologic or hydrogeologic information for potential inclusion in a variance.
This information will have the following two uses:
provide general geologic and hydrogeologic data
associated with the site that is important or
necessary in evaluating the potential migration of
hazardous waste from the tank system to ground or
surface water; and
provide the hydrogeologic information (e.g.,
hydraulic conductivity, porosity) necessary for
performing an environmental fate analysis as described
in Chapter 5, Exposure Point Concentrations.
In general, a description of the hydrogeologic framework of an area should
include a discussion of the following factors:
important climatic aspects of site area (e.g.,
precipitation and infiltration);
structural attitude and distribution of bedrock and
overlying strata;
chemical and physical properties of underlying
strata (soil and rock), including lithology,
mineralogy, and hydraulic properties;
soil characteristics, including soil type and
distribution, and attenuative properties; and
ground-water regime, including water table depths,
aquifer types, flow paths and rates.
This chapter identifies information that will be necessary to fully and
adequately characterize the hydrogeology of a site (and include in an
application). This complete characterization will be required for most
variance applications. However, if the quality of ground water beneath the
site is very poor (i.e., is not a current or potential future source of
lj Section 264.193(g)(2)(i)(B) (51 Federal Register 25475, July 14,
1986).
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OSWER Directive 9483.00-2
3-2
drinking water), or if an applicant can show that there are no pathways of
exposure to ground water (as discussed in Chapter 5), investigative or data
gathering efforts can be reduced. These potential situations should be
assessed before designing and conducting site-specific hydrogeologic studies.
Examples of data reduction that may be possible if either of these situations
exist are as follows:
extensive subsurface and surficial investigations
should not be needed; applicant may be able to present
general geologic and hydrogeologic information
available from published sources;
detailed aquifer characterization, including-the
measurement of hydraulic conductivity and gradients,
and the preparation of potentiometric surface maps,
etc., should not be needed. It would be necessary to
describe any underlying potable aquifer and to show
its lack of interco'nnection with the upper aquifer;
and
the environmental fate analysis (transport modeling)
of Section 5.2 and the calculation of parameters for
the analysis need not be done.
It must be emphasized that the Regional Administrator may require additional
information to supplement that which is identified in this chapter for
inclusion in a variance application.
This chapter has been divided into six subsections. Section 3.1
summarizes investigative techniques that data gathering efforts, detailed in
subsequent subsections, often require. Sections 3.2 through 3.6 are organized
around the types of information that are needed to characterize a
site-specific hydrogeologic setting. Section 3.2 describes the types of
climatic information applicants should identify for assessing the impacts of
rainfall patterns. Section 3.3 discusses regional and sice-specific data that
applicants should present to characterize surface and subsurface geology.
Section 3.4 discusses unsaturated zone information, such as soil types,
extents, and properties necessary for a hydrogeologic characterization.
Section 3.5 describes aspects of the saturated zone that should be assessed in
the application, including the aquifer system and hydrogeologic properties,
and ground-water flow patterns. Finally, Section 3.6 describes surface water
features that should be considered for inclusion in the application. These
sections and the types of information they discuss are illustrated in Exhibit
3-1.
While this chapter is intended to give the variance applicant an idea of,
and a guide to, the extent of necessary data-gathering efforts, it should not
be viewed as a "checklist" for the completeness of an application's
hydrogeologic characterization. The exact types and amounts of information
that will need to be collected and presented will vary from site to site,
e.g., sites with more heterogeneous subsurfaces require more information to
characterize the hydrogeology.
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OSWER Directive 9483.00-2
Exhibit 3-1
OVERMEW OF PROCESS TO CHARACTERIZE SITE HYDROGEOLOGY
SECTION 3.2
Climate:
Precipitation
Temperature
Evaporation
Runoff
Infiltration
SECTION 3.3
Regional and Site Geology:
Regional geology
Topography
Site geology
Site stratigraphy
SECTION 5.4
SECTION 3.5
SECTION 5.6
Unsaturated Zone:
Soil types
Soil stratigraphy
Chemical and physical
properties
Saturated Zone:
Aquifer system
Hydrogeologic properties
Recharge/discharge zone
Ground-water flow direction
Ground-water flow rate
Surface Water:
Proximity wnh respect to
tank system
Physical properties
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OSWER Directive 9483.00-2
3-4
3.1 INVESTIGATIVE TECHNIQUES
This section summarizes the investigative techniques used to collect
hydrogeologic data. The purpose of this section is to provide the applicant
with an overview of these investigative techniques. It is to be stressed that
much of the information identified for characterizing the hydrogeology
associated with a site will probably be obtained through extensive laboratory
and field investigations, including hydrogeologic, geologic, soil, and water
budget surveys, conducted by qualified professionals thoroughly familiar with
such methods.
Professionals qualified to perform such investigations span a range of
disciplines and include hydrologists, geologists, chemists', geochemists, soil
scientists, etc. Because these professionals are familiar with the data
necessary to characterize a site and the relevant investigative technqiues,
detailed information about hydrogeologic parameters to be included in the
variance application; how such parameters are measured or-gathered, and their
importance in assessing pollution potential, is not provided in this chapter.
Subsequent sections provide a general discussion of the types of data
necessary for characterizing a site's hydrogeology and the types of
investigative techniques that will likely be used to collect such data.
Additional sources of information on investigative techniques can be found in
the references of this document.2-1 Applicants should realize that the
amount of information and investiative efforts needed to characterize a site
is extensive. However, such assessments are critical to evaluating the
potential migration of hazardous waste released from a tank system.
A variety of investigative techniques are available to collect data for a
hydrogeologic characterization. Exhibit 3-2 illustrates a number of
techniques that an applicant may employ to perform various aspects of
hydrogeologic investigations. Exhibit 3-3 lists some corresponding formats
for presenting the resulting data.
The site-specific investigative program should include direct methods
(e.g., borings, piezometers, geochemical analysis of soil samples) for
determining the site hydrogeology. Indirect methods (e.g, aerial photography,
ground penetrating radar, resistivity), especially geophysical studies, also
may provide valuable sources of additional information (such as porosity).
Thus, an applicant should combine the use of direct and indirect techniques in
the investigative program to produce an efficient and complete
characterization of the facility site.
In obtaining the information necessary to characterize a site's
hydrogeology, the owner/operator should review the available literature of the
site area and, when appropriate, use such information in conjunction with site
2J Discussions on the characterization of hydrogeology, including
geology, aquifers, and ground-water flow paths, can also be found in Chapter 1
of the following document: EPA, RCRA Ground-water Monitoring Technical
Enforcement Guidance Document, Office of Solid Waste and Emergency Response,
September 1986.
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OSWER Directive 9483.00-2
3-5
EXHIBIT 3-2
HYDROGEOLOGIC INVESTIGATIVE TECHNIQUES
FOR SUBSURFACE INVESTIGATIONS
Definition of Subsurface Materials (Geology):
Survey of existing geologic information
Soil borings
Rock corings
Material tests (grain size analyses, standard penetration.
tests, etc.)
Geophysical well logs (point and lateral resistivity and/or
electromagnetic conductance, gamma ray, gamma density, calipher,
etc.) a/
Surface geophysical surveys (D.C. resistivity, E.M.,
seismic) a/
Aerial photography (fracture trace analysis)
Detailed lithologic/structural mapping of outcrops and trenches
Identification of Ground-Water Flow Paths (Hydrology), Directions, and
Hydraulic Conductivities:
Installation of piezometers; water level measurements at
different depths and locations
Slug test and/or pump tests
Tracer studies
Estimates based on sieve analyses
a/ These techniques can be used to supplement information gathered from
other sources and may be necessary to perform at some sites (e.g., very
heterogenous areas).
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OSWER Directive 9483.00-2
3-6
EXHIBIT 3-3
EXAMPLES OF'FORMATS FOR PRESENTING
HYDROGEOLOGIC INFORMATION
Narrative description of geology
Geologic cross sections
Geologic or soil maps (plan-view)
Geologic or soil- stratigraphic columns or maps
Boring logs or coring logs
Raw data and interpretive analysis of geophysical studies
Raw data and interpretive analysis of material tests
Narrative description of ground water with flow patterns
Water table or potentiometric maps (plan view) with flow lines
Structure contour maps of aquifer and confining layers (plan view)
Raw data and interpretive analysis of slug tests, pump tests, and tracers
studies
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OSVER Directive 9483.00-2
3-7
investigations. Such a review may provide a preliminary understanding of the
distribution of sediments and rock, general surface water drainage, and ground
water. Available materials could include published geologic and topographic
maps, hydrogeologic reports, aerial photographs, well drilling logs, and soil
surveys. Exhibit 3-4 summarizes the principal sources of such geotechnical
data.
A review of avail.ible information can also serve to 'guide the site-specific
investigation (e.g., well placement), and can reduce necessary data gathering
efforts, i.e., an applicant may be able to present and use data already avail-
able. However, the burden of proof is clearly on the applicant to demonstrate
that a variance is appropriate. In many situations, the extensive site-
specific data described in this chapter will be required to yield an adequate
demonstration. Facility owners/operators with on-site tanks and on-site land
treatment, storage, or disposal units may have filed a RCRA Part B permit
application. If so, much of the data identified for inclusion in the variance
application may already be available.
The hydrogeologic data identified in this chapter for inclusion in a
variance application should be presented using the methods suggested in this
technical document (e.g., tables or maps). Additionally, the variance
application should contain a section that compiles and discusses the data and
the hydrogeologic setting of the site area as a whole. This section could
consist of a hydrogeologic study report (with figures) prepared by
geotechnical professionals. Much of the actual data such as well logs and
laboratory analyses may lend itself to inclusion in appendices.
3.2 CLIMATIC CHARACTERISTICS
This section describes the types of climatic information that will likely
be necessary for identifying the impacts of surrounding rainfall patterns.
These impacts will be evaluated with respect to the adverse effects caused by
a release of contaminants to surface water and the surrounding land.3-1
Additionally, the amount of water that reaches or recharges ground water in an
aquifer is determined, in part, by climatic elements -- or more specifically
by the amount of precipitation not lost by evaporation (affected by
temperature, humidity, and wind) -- and runoff. Thus, these parameters have
direct implications to the transport of contaminants and the effects of annual
rainfall on contaminant transport through the unsaturated zone should also be
assessed.
Impacts of rainfall patterns can be divided into two categories: (1)
surface water dilution potential; and (2) runoff potential. Surface water
dilution potential affects the ability of nearby surface water to assimilate
contaminants and consequently reduce contaminant concentrations. Runoff
JJ This evaluation is required for considering the potential adverse
effects of a release on surface water quality (40 CFR 264.193(g)(2)(iii)(B)
(51 Federal Register 25475)) and surrounding land (40 CFR 264.193(g)(2)(iv)(A)
(51 Federal Register 25475)).
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OSVER Directive 9483.00-2
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EXHIBIT 3-4
PRINCIPAL SOURCES OF GEOTECHNICAL DATA
Published Data:
1. LJSGS- surficial geology maps
2. USGS bedrock geology maps
3. USGS hydrological atlases
4. USGS basic data reports
5. State and County geologic and hydrologic maps and reports
6. National and local technical journals, magazines and conference
proceedings
7.
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OSWER Directive 9483.00-2
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potential affects the transport of contaminants to surface waters and the
surrounding land. Surface water dilution will be evaluated concurrently with
surface water transport (discussed in Chapter 5, Exposure Point
Concentrations). The effects of runoff will be evaluated in the environmental
impact evaluation (discussed in Chapter 7, Environmental Impact Evaluation).
Consequently, this section discusses the necessary climatic information rather
than the assessment of the impacts. Some of the elements that define the
climatic characteristics >ind hydrology of a region include precipitation
(i.e., rainfall), temperature, evaporation, runoff, and infiltration. The
type of information necessary to assess these phenomena are described below.
Precipitation. Monthly and annual rainfall and snowfall (expressed as
its equivalent in rainfaj.1) can be obtained from the National Oceanic and
Atmospheric Administration (N'OAA), or the National Weather Service.
Additionally, daily records are published in "Cliraatological Data" and "Hourly
Precipitation" by the U.S. Environmental Data Service.
Regional precipitation data may be presented and used if they were
generated within a reasonably close distance to the tank site (approximately
15 km) and are representative of rainfall conditions at the site. Regional
data collected at greater distances from the site should be correlated with
available on-site data. The monthly mean and range of these data, the
specific time period from which the data came, and the location of the rain
gauge(s) in relation to the facility should be provided. Precipitation data
can be presented in tables showing monthly and yearly averages over a period
of time.
The applicant should submit data on specific storm frequency patterns.
The predicted amount of precipitation produced over a 24-hour period by storms
with return frequencies of 1, 10, 25, 50 and 100-years should be included. If
the site is in a potential flood-plain zone, flood levels in relationship to
the sice should be identified for these storms. This information should be
available from the Federal Insurance Administration (FIA) in the form of maps
or other data. If the facility has any special flood prevencion devices,
(e.g., dikes, bermsj, chase devices could also be shown on a site map. Any
special site conditions chac affect infilcracion and runoff should also be
discussed.
Temperature. Ambient air temperature (degree) data can be useful in
the general assessment of the climatic setting of a site and may be useful in
the assessment of potential volatilization of contaminants. This regional
information should be available from similar sources used to obtain
precipitation information. Temperature is generally reported as monthly and
annual averages over the period of record and is important in assessing
evaporation.
Evaporation. Evaporation and.transpiration (evapotranspiration) rates
(depth of water per unit time) reflect the amount of precipitation returned to
the air. Evaporation rates are measured by NOAA, and evapotranspiration rates
can be estimated from these data. Evapotranspiration rates can also be
obtained through "site-studies (using lysimeters), or through published sources
if the nearest data set (collected at a gauging station) is representative of
the site conditions.
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Runoff. Surface runoff is the runoff component of interest for
assessing the transport of contaminants over the land surface. Specifically,
overland flow (i.e., the part of surface runoff that flows over the land
surface toward channels) is of interest. The applicant should identify the
potential of overland flow to transport contaminants to land areas of
particular interest (e.g., agricultural land) and surface water. This
potential depends on the surrounding surface characteristics (e.g., slope,
soil typo, vegetation, paved areas). If the potential for the transport of
contaminants is significant, then the applicant will likely have to conduct a
detailed analysis of overland flow (i.e., the identification of the quantity
and quality of overland flow). Such an analysis would 1-ikely require the use
of a runoff simulation model such as the Storm Water Management Model-
(SWUM)."J
Infiltration. The maximum rate at which water (precipitation) can
enter the soil is the infiltration rate (depth of water per unit time).
Infiltration rates (average annual) are important in the determination of the
velocity of ground water moving downwards through~soil and, hence, in the
modeling and determination of contaminant transport rates (see Chapter 5).
Records of estimated infiltration rates for an area may be available from
sources such as the U.S. Department of Agriculture (Soil Conservation
Service). However, it will probably be necessary to estimate this value by
taking the average percipitation rate (average annual) and subtracting
evapotranspiration and runoff rates (average annual).
3.3 REGIONAL AND SITE GEOLOGY
Applicants will need to present a thorough characterization of surficial
and subsurface geology at a site. In order to detail the geology beneath and
around the site and, therefore, be able to identify potential pathways of
contamination, the applicant (using qualified professionals) must collect and
submit extensive information on the geologic properties and features of
individual strata beneath and surrounding a site. Subsections 3.3.1 and 3.3.2
discuss the necessary information to characterize regional and site surficial
geology and subsurface geology, respectively.
3.3.1 Surficial Geology
This subsection discusses the types of maps and other illustrative
exhibits that can be used to characterize on-site and surrounding surficial
geology. These maps and the type of illustrated information include:
regional geologic map used to characterize regional
geologic units and structural features;
topographic maps used to characterize site-specific
surficial relief;
UJ "Metcalf and Eddy, Inc., University of Florida, Gainesville, Fla. ,
Water Resource Engineers, Inc., Storm Water Management Model, EPA, Vol. 1,
1971.
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OSWER Directive 9483.00-2
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site geologic map used to characterize detailed
site-specific surficial geology; and
aerial photograph used to highlight surficial
information (e.g., surrounding vegetation).
These maps are described below.
Regional Geologic Map. The applicant should provide an overview of the
regional geology of an area, including the identification of the geologic
provinces or setting of the area (e.g., Basin and Range" Province), if
applicable, and any pertinent geologic history. A large scale plan-view
geologic map, available from published sources such as the- U.S. Geological
Survey, could be included with the application to show geological units and
structural features of the region.
Topographic Map. Surficial features may affect ground-water hydrology;
therefore, applicants should include a topographic map of the site. The
topographic map should be constructed under the supervision of a licensed
surveyor, and extend to a distance and scale deemed appropriate by
professional judgment (coverage of the area within 100 feet of the site at a
scale of 1 inch equal to not more than 200 feet may be adequate.Sj)
Contours must be shown on the map. The contour interval should be sufficient
to clearly show the pattern of surface water flow in the vicinity of, and
from, the hazardous waste tank site. A suggested contour interval is two
feet. The map should clearly show the map scale and date, surface water
locations (including intermittant streams) (see Section 3.6), orientation of
the map, boundaries of the site, and the location and components of the
tank.'J A larger area, regional. topographic map, prepared from published
sources, may also be of use in the assessment of the application and should be
considered for inclusion.
Site Geologic Map. Detailed surficial geologic information of the sice
area should be collected and presented on a plan-view geologic map. This map
should clearly delineate the tank(s) location and should show structural
attitude, distribution, and lithology of surficial bedrock or strata. Faults
located on or near the site should be located on the map and (along with
geologic information) discussed in the geologic narrative of the application,
keeping in mind the potential of such features to act as pathway's for the
migration of hazardous waste. While published sources will be of use, the
level of detail needed for the inclusion of this information will probably
need to be obtained via field and mapping surveys. Trenching may be needed to
|J As required in a RCRA Part B application, §270.14.
*J Cotnmenserate with other sections of this manual, this map could show
surrounding land uses (see Chapter 4), a wind rose (i.e., prevailing wind
speed and direction), locations and illustrations of man-made features (e.g.,
buildings, on- and off-site wells), and any other potential sources of
contamination (e.g., hazardous waste treatment, storage, or disposal units on
site).
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accurately document the location of faults. Professional judgement, should be
used in determining the area of map coverage.
Aerial Photography. An aerial photograph of the site, if available,
should also be considered by the applicant for inclusion in the application.
A useful photograph would clearly delineate the site and adjacent off-site
features, such as surface water bodies, municipalities, and residences.
3.3.2 Subsurface Geology
This subsection discusses the types of information that should be included
in an application to adequately characterize the subsurface geology at and
surrounding a site. This information includes:
regional geologic cross sections used to identify
geologic units and structure in the area; and
stratig'raphic maps used to depict the subsurface
site stratigraphy.
Methods used to collect this information (e.g., stratigraphic investigations
utilizing soil and rock borings) are also discussed.
Regional Geologic Cross Sections. On a regional scale, available
generalized geologic cross sections that show subsurface geologic units and
structures in the area of the site could be included. These data are intended
to show unique regional characteristics and their relationships to the site,
and would cover a larger area than the subsurface stratigraphic investigations
and resulting maps discussed below.
Stratigraphic Investigations. To assess the geologic properties of
strata beneath a site that are likely to influence the migration of
contaminated ground water, the variance applicant will need to have
geotechnical professionals conduct a thorough subsurface stratigraphic
investigation using techniques such as:
cest borings;
test pit excavations;
rock coring;
geophysical surveys; and
laboratory analysis.7-1
In addition to the types of information discussed here, these investigations
will also provide information on site features such as soil and aquifer
characteristics (discussed in Sections 3.4 and 3.5). Thus, data collection
efforts should coordinate with those discussed in Sections 3.4 and 3.5.
Direct methods (e.g., lithologic analysis) should be employed to identify
the lithology and structural characteristics of the subsurface. This
7J A detailed description of these techniques and the types of data that
can be collected through their use can be found in sources listed in the
References section of this document.
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OSWER Directive 9483.00-2
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identification will involve a soil/rock boring program. In some situations
(e.g., shallow aquifer systems), test pits (shallow excavations) may be
feasible to use and can reduce data gathering efforts somewhat. These
investigations serve to establish the small-scale geology of the area beneath
the facility and place it in the context of the geology of the region or
locale.
Prior to initiating an on-site investigation, available information (e.g.,
reports, maps, research papers) on local stratigraphy, depositional
environment, and tectonic history should.be obtained. This information can
serve to provide an estimate of the distribution and types of geologic
materials likely to be encountered and, thus, assist in the appropriate
placement of investigatory boreholes. Obviously, any previous drilled
boreholes on or near a site will provide useful data.
Professional judgment must be used in establishing the density of
boreholes (i.e., number per unit area) that is needed to characterize the
geology beneath a. site. Sites with simple underlying geology (i.e.,
horizontal, thick, unfractured, homogeneous, geologic strata that are
continuous across a site and are substantiated by regional geologic
information) or where indirect methods (e.g., geophysical surveys) are used to
correlate well log data, will normally require relatively few boreholes.
Generally, sites with heterogenous stratigraphy (e.g., discontinuous units, or
pinchout zones, across the site) may require an increase in the density of
boreholes to adequately characterize subsurface units.
The distance between boreholes will depend on site-specific criteria, yet
should be close enough so that cross sections constructed from collected data
will accurately portray stratigraphy with minimal reliance on inference.
After examining initial well logs, it may become evident that additional
boreholes will be necessary to completely characterize the subsurface
stratigraphy. The need for additional boreholes is a common occurrence since
the majority of hydrogeologic settings are complex. Data and observations
derived from initial boreholes may be used to guide the placement of future
ones. The depth of boreholes will also be site-specific and will depend on
:he aquifer system present at the site (as discussed in Section 3.5) and the
extent of significant hydrogeologic units within the system and below it.
Borehole samples should be collected for each significant stratigraphic
contact and formation, especially any confining layers. Continuous cores
should be taken initially to. ascertain the presence and distribution of small-
and large-scale permeable layers and to obtain stratigraphic control. Once
stratigraphic control is established, samples can be taken at regular (e.g.,
five-foot) intervals substituting for continuous cores. After completion of
the sampling program, boreholes should be sealed with material at least an
order of magnitude less permeable than the surrounding soil/sediment/rock in
order to reduce the number of potential contaminant pathways.
Collected samples should be logged in the field by a qualified geologic
professional. Drilling logs and field records should be prepared detailing
the following information:
gross petrography (e.g., soil classification or rock
type) of each geologic unit, including the confining
unit (if present);
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OSWER Directive 9483.00-2
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gross structural interpretation of each geologic
unit and structural features (e.g., fractures, fault
gouge, solution channels, buried streams or valleys),
bioturbation zones, petrology, and discontinuities;
development of soil zones and vertical extent and
field description of soil types (prior to any
necessary laboratory analysis) (see Section 3.4 for
additional discussions on soil information to include
in an application);
depth of water-bearing unit(s) and vertical extent
of each unit (see Section 3.5 for additional
discussions on aquifer information); and
blow counts, colors, and grain-size distribution(s).
Copies of drilling and boring logs should be submitted with the variance-
application.
In addition to field descriptions as described above, the applicant should
provide, where necessary, a laboratory analysis of each significant soil zone
(as discussed in greater detail in Section 3.4) and geologic unit. These
analyses should contain the following information:
mineralogy and mineralogic variation of confining
units/layers, especially clays '(e.g., microscopic
analysis and other methods such as X-ray diffraction
as necessary);
petrology and petrologic variation of each unit
present under a site, concentrating on those above the
confining unit/layer (e.g., petrographic analysis,
other laboratory methods for unconsolidated materials
as deemed necessary) to determine among other things:
degree of crystallinity and cementation of matrix;
degree of sorting, size fraction, and textural
variation;
existence of small-scale structures that may
affect fluid flow;
moisture content and moisture variation (spatial and
temporal) of each significant soil zone (see Section
3.4) and geologic unit; and
hydraulic conductivity and variation of each
significant soil zone and type and geologic unit (see
Sections 3.4 and 3.5 for further discussion of these
parameters).
Copies of laboratory analysis results should be included with the application.
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Indirect methods of geologic investigation such as geophysical studies may
be used to augment the evidence gathered by direct field methods, but should
not be used as a substitute for them. Surface geophysical studies, such as
resistivity, electromagnetic conductivity, seismic reflection, seismic
refraction, and borehole methods (e.g., electromagnetic conductivity,
resistivity, and gamma ray) may yield valuable information on the depth to any
confining unit, the types of unconsolidated material(s) present, the presence
of fracture zones or structural discontinuities, and the depth to the
potent iornetric surface. Additionally, geophysical methods may have their
greatest utility in correlating the continuity of formations or strata between
boreholes. The result is the efficient compilation of .extensive site data
without drilling an excessive number of boreholes. Geophysical methods,
however, should have been used primarily to supplement information obtained
from direct sources.
Stratigraphic Maps. The variance applicant should use the data
collected from the subsurface (borehole) investigations to prepare and submit
a set of Stratigraphic cross sections or maps depicting the subsurface site
stratigraphy. Several cross sections may be required to depict significant
geologic or structural trends and reflect geologic/structural features in
relation to local and regional ground-water flow. The areal and vertical
extent of the geologic units can be presented in several ways. For complex
settings, the most desirable presentation is a series of structural contour
maps for the top or bottom of each unit. Vertical sections and isopach maps
can also be used since they are generally more graphic and are useful as
supplements .to the structural contour maps.
On each cross section, the applicant should identify the following: the
depth, thickness, and areal extent of each Stratigraphic unit; all
Stratigraphic zones and lenses within the near-surface zone of saturation;
petrography of significant formations/strata; significant structural features;
Stratigraphic contacts between significant formations/strata; zones of high
permeability or fracture; the location of each borehole and depth of
termination; depth to the zone of saturation (as further discussed in Section
3.5); and depiction of any geophysical logs. A scale of no greater than one
inch:200 feet is suggested for these maps. With an adequate number of cross
section lines, a very useful and illustrative fence diagram (3-dimensional)
can be constructed and submitted with the application. A table that
summarizes the subsurface geologic information should also be submitted.
3.4 UNSATURATED ZONE CHARACTERIZATION
In describing the potential behavior of contaminants released to ground
water from a hazardous waste tank, two major subsurface zones must be
examined: the unsaturated soil zone (vadose zone), and the saturated zone or
aquifer. The unsaturated zone extends from the soil surface down to the
ground-water table, and collection of information on its physical and chemical
properties are an important part of a subsurface investigation (and hence a
variance demonstration).
Though published maps and aerial photographs of an area may provide useful
soil information, detailed on-site soil explorations or surveys may be
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OSWER Directive 9483.00-2
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necessary to obtain detailed information. This information is typically
obtained through the use of the same investigative measures discussed for
obtaining geologic information, including soil borings, test pits, and
geophysical investigative methods, followed by laboratory analyses of the
samples collected.1-1 These surveys would be especially important to conduct
in heterogeneous areas that show variations in subsurface materials and
stratigraphy. It is likely that at least some of the information discussed in
this section for inclusion in the variance application will be acquired
through the soil and rock borings conducted to investigate the subsurface
stratigraphy (Section 3.3).
This section discusses the types of soil characteristics that should be
investigated at a site. These characteristics include:
soil types and extents illustrated on soil maps; and
chemical and physical properties of the soil strata,
such as organic carbon content and moisture content.
The variance applicant should submit collected data in both tabular and
graphic form. As with the subsurface stratigraphic investigation, the
applicant should submit copies of any drilling and boring logs and laboratory
analyses.
Soil Maps. In characterizing the surficial soils at homogeneous sites,
published or otherwise available maps may be helpful if soils are
undisturbed. While less likely to be available in adequate detail, published
sources may also provide subsurface soil information. If a site has been
disturbed so that published sources are inadequate, a soil survey will need to
be conducted to determine the types and extents of soil at the site. The
first step in a soil investigation or survey is identifying and classifying
soil types at the site. The U.S. Department of Agriculture's soil
classification scheme is suggested for use. This scheme is based on soil
grain-size distribution.
By conducting a soil survey, the area extent of soil types at the site can
be identified. Results should be presented on a plan-view soil map (suggested
scale no greater than one inch:200 feet). A cross sectional analysis of the
soils underlying a site should also be conducted. Results should be presented
via maps showing soil thicknesses, types, and extents (lateral). The
information needed to prepare these cross sections should be available from
soil borings or test pits. What constitutes an adequate number of soil cross
sections will vary from site to site depending on conditions', and should be
determined by professional judgment. The location of each borehole or test
pit should be identified on each cross sectional map.
Soil Properties. Soil properties that are important to measure or
determine for understanding the fate and transport of potential contaminants
include: porosity (total and effective), hydraulic conductivity, moisture
*J See References for sources of information regarding soil
investigative techniques.
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OSWER Directive 9483.00-2
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content, organic carbon content, cation and anion exchange capacity, and
grain-size distribution. These parameters should be determined for each
significant soil zone (i.e., several soil types having similar
characteristics) underlying a site and should be presented in the variance
application as a table summarizing soil information. Likewise, sampling and
laboratory procedures used to determine these properties should be presented
and results tabulated.
Many of the soil properties discussed here will be easier to determine and
measure if the assumption is made that saturated conditions (no gaseous pore
space) exist. For modeling efforts, this assumption would result in a worst
case scenario, i.e., a conservative approach, but often allows simpler
determinations of soil parameters to be made.
All.of the parameters discussed below are important in contaminant
transport modeling (as discussed in Chapter 5). The soil parameters of
organic carbon content, cation and anion exchange capacity, and grain size '
distribution will be especially important to determine and present if an
applicant includes soil (or other matrix) attenuation mechanisms'-1 in the
calculation of exposure point concentrations (see Chapter 5).
Total Porosity: The total porosity (the percentage of
void space in the material) affects the ability of a soil
to hold and possibly transmit any released contaminant.
While this parameter can be estimated from the literature
with knowledge of the soil type, more specific values
(determined from field and/or laboratory measurements) may
be required. Effective porosity is the percentage of pore
space that is capable of transmitting fluid. Values for
this term will likely be needed for modeling efforts and
can be determined through laboratory measurements.
Hydraulic conductivity: Hydraulic conductivity
(distance/time) in the unsaturated zone is a measure of the
ability of the soil to transmit fluid. It is a function of
the soil moisture content and this functional relationship
can be approximated from soil type. These values will be
needed for modleing contaminant flow in the unsaturated
zone. Hydraulic conductivity in the unsaturated zone is
difficult to measure. Alternatively, the saturated
hydraulic conductivity of the unsaturated zone can be used
in modeling efforts. This assumption is conservative
because it would imply faster contaminant movement and
allows the investigator to measure saturated hydraulic
conductivity by field or laboratory tests (a much simpler
measurement than the estimation of the functional
relationship between conductivity and moisture content in
the unsaturated zone).
SJ Attenuation mechanisms are processes that reduce the velocity or
amount of a contaminant in the subsurface. Aquifer matrix or media
characteristics that affect the stability of potential contaminants should
also be described if they are used to support attentuation claims.
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Moisture content: During the soil survey, moisture
content (dimensionless) should be measured for each soil
type present at the site. This information is mainly of
use for interpretive purposes, i.e., understanding the
hyd'rogeologic setting of the site, and is measured through
laboratory procedures. For modeling use, if it is assumed
that saturated conditions exist, moisture contents need not
be measured.
Attentuation: To substantiate attenuation mechanisms,
applicants should submit data describing the organic and
mineral content, the cation and anion exchange" capacity,
and the grain size of each soil type along the expected
path of contaminant migration. These parameters are
determined through laboratory analysis and are discussed
below.
The degree to which many (organic) contaminants will
adsorb to soil material is directly proportional to
the organic carbon content (percentage) of the soil.
Organic carbon contents are also important in
calculating contaminant retardation in transport
modeling. In making this calculation, applicants will
need to measure soil values for bulk density (the
ratio of the mass of soil to the bulk volume of
soil). Bulk densi.tyi obviously, is dependent on the
amount of sand, clay, organic matter, hydroxides, etc.
in the soil.
The ion exchange capacity (example of units:
milliequivalents/gram) is a measure of the tendency
for soil constituents, particularly clays, to attract
and hold ionic contaminants. This process can be very
important if there is a subsurface clay layer at a
sice capable of crapping pocencial contammancs before
they reach ground water. For inorganic contaminants,
this property is also important in calculating
retardation (through distribution coefficients) in
transport modeling.
Grain-size distributions should be derived from or
measured (by sieving) during soil classification. It
also may be useful to further examine (through
laboratory measurements) distribution of finer
materials present in the soil to determine information
such as amounts and type of clay. Such information
can be used to further assess attenuation mechanisms
such as retardation.
3.5 SATURATED ZONE CHARACTERIZATION
In addition to understanding site features such as the areal geology, it
is necessary for an applicant to understand and present a thorough
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characterization of the ground-water system or saturated zone at a site.
Unless available from prior site investigations, an extensive subsurface
investigation will probably be necessary to obtain much of the information
discussed in this section. This investigation will involve the drilling and
implacement of ground-water wells and piezometers, and subsequent aquifer
testing, laboratory analyses, and water table mapping.
The variance applicant should research available sources (reports, etc.)
of information on area hydrology since chis information can yield a first
approximation of site-specific ground-water characteristics. These sources
can also aid in the placement of investigative wells and the understanding of
resulting well data. If complete enough, such sources may reduce
data-gathering efforts-.
The number of investigative ground-water wells that should be drilled to
adequately characterize the hydrogeologic regime will vary from site to site.
As small a number as three wells has been used in ground-water investigations,
but a larger number is often necessary to provide accurate areal data.loj
The type of well established will depend upon aquifer characteristics
(especially aquifer materials). Wells (or piezometers11-1) will need to be
cased, sealed and screened as appropriate for the type of information being
collected (e.g., horizontal and vertical hydraulic conductivity). Tests
conducted at these wells will include sampling of geologic materials,
measurements of water levels, performance of pumping tests, and analysis of
water quality and quantity (or yield). Copies of all well logs and laboratory
and field test results should be included with the 'variance application.
The level of effort spent in field and laboratory programs should be
adequate to fill any knowledge gaps concerning the site's hydrogeologic
setting. Discussions of the various methods and testing techniques available
for the accurate definition of the ground-water regime at a site can be found
in numerous references, a few of which are included in this document.
This section has been divided into two subsections:
Subsection 3.5.1 dicusses how resulting data are
used to establish aquifer characteristics including
aquifer extents and composition, and hydrogeologic
properties such as hydraulic conductivity and porosity.
10J When determining the placement of ground-water wells, the monitoring
requirements discussed in Chapter 4 for establishing existing ground-water
quality should be considered. This consideration would ensure that wells
established to characterize ground-water flow and direction could also be used
to assess ground-water quality, thus potentially reducing the necessary number
of investigative wells.
llj Piezometers are wells or boreholes that are sealed throughout most
of their depth in such a way that they measure the hydraulic head at a
particular depth in an aquifer.
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Subsection 3.5.2 discusses the use of collected data
for establishing ground-water flow characteristics,
such as rates and direction of ground-water flow.
Methods of presentation for collected data are described in the subsequent
subsections.
3.5.1 Aquifer Characteristics
Using well data, detailed information should be presented in the
application describing the aquifer system and the hydrogeologic properties of
the saturated zone underlying the site, as discussed below. Methods used to
obtain this information should also be discussed in the application.
Aquifer System. Field and descriptive efforts should characterize the
uppermost aquifer as well as any lower aquifers that are hydraulically
interconnected.with the aquifer of Interest. Listed below are several aquifer
characteristics that should be identified for the aquifers of interest.
Aquifer Boundaries: The identification of a lower
boundary (or confining layer) can help delineate the
vertical extent of the uppermost aquifer. Some
hydrogeologic settings (e.g., alluvial depositional
environments) do not contain any clear lower aquifer
boundaries. In such a case, it may be adequate to limit
the aquifer characterization to the,expected downward
migration depth of a contaminant. Professional judgment
should be used in assessing interconnection between upper
and lower aquifers (and the resulting levels of efforts
required to characterize lower aquifers). A lack of
interconnection may be indicated if the lower boundary of
the upper aquifer consists of a thick confining layer
(aquitard). Evidence of a significant degree of
interconnection between aquifers may be indicated if the
confining layer pinches out within the site boundary, the
aquitard is fractured or karst, numerous wells that are
inadequately sealed penetrate the aquitard, or pumping (or
injection) tests show a significant response in the aquifer
on the other side of the aquitard. It is also important to
identify the presence and position of any hydraulic
boundaries (such as impermeable barriers or beds) that
limit the aquifer system at a site.
Type of Aquifer: Following the identification of
aquifer boundaries, the aquifer(s) beneath the site should
be identified as being either an unconfined, or water-table
aquifer (where the water table forms the upper boundary),
or a confined aquifer (where the aquifer is confined
between two layers of low permeability beds in a
stratigraphic sequence).
Saturated Zones: Saturated zones above the uppermost
aquifer (such as low permeability clay) can also act as
pathways for contaminant migration and, if present, should
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be identified and described. These perched water zones or
perched aquifers present underneath a site should be
identified.
Scratigraohic Names: Aquifers are often called by their
stratigraphic names (e.g., The Floridian aquifer in
Florida). If an aquifer beneath a site is formationally
named (as evidenced by common usage or published reports)
such a name should be included in the application
discussion.
Classification of Units: The applicant should classify
the hydrogeologic units within and below the uppermost
aquifer on the basis of their lithology and hydrogeologic
properties. The classification should generally extend
from the surface to the aquitard underlying the uppermost
aquifer. The lithology or composition of the aquifer(s)
materials can be determined during investigative well
drilling (including stratigraphic borings). The
classification of units should be graphically presented as
a hydrogeologic column or cross section with an
accompanying description. This presentation can be
combined with the maps discussed below for delineating the
extent of the hydrogeologic units.
Extent of Units: The applicant should delineate the'
areal and vertical extent of significant hydrogeologic
units (the determination of the vertical extent of the
uppermost aquifer has been discussed above in Aquifer
Boundaries). The extents of these units can be presented
in several ways. For complex settings, the most desirable
presentation is a series of structural contour maps for the
top. or bottom of each unit. Vertical sections or columns
and isopach -maps are also frequently used. However,
vertical sections and isopach maps may not contain all the
information available. They are most useful as a
supplement to the structural contour maps. Because the
construction of any of these diagrams involves
interpolation and extrapolation of limited data, the
diagrams should also show the location of control points.
For simple geologic settings in which the hydrogeologic
units are laterally extensive and flat lying, maps of
sections may not be necessary. For example, a table
listing the elevations of the top or bottom of each unit
may be adequate. These exhibits can be presented
separately with a narrative discussion of the site's
aquifer or aquifer system, or they may be part of the
stratigraphic cross sections discussed in Section 3.3. The
location of any local faults should also be indicated. Any
stratigraphic units that behave as a subsurface impermeable
barrier or confining layer (aquitard/aquiclude) should be
identified as such.
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Hydrogeologic Properties. Each of the significant stratigraphic units
located in the zone of saturation should be characterized by hydrogeologic
properties such as hydraulic conductivity (vertical and horizontal) and
effective porosity. These parameters describe aquifer characteristics that
control the movement of ground water and, hence, the ability of the aquifer to
retain or pass potential contaminants. Both are needed for a general'
understanding of the hydrogeologic setting at a site and for ground-water
transport modols that use velocity measurements (as discussed in Chapter 5).
Hydraulic conductivity and porosity of aquifier materials can be determined by
using laboratory or field methods. Tests that are conducted to define the
hydrogeologic properties of stratigraphic units should be performed in the
field. Laboratory tests may be used to substantiate field test results, but
should not be the sole basis for determining aquifer characteristics.
Because each of these parameters can vary from point to point even within
the same aquifer, any areal variations must be identified. The amount of data
needed to accurately determine hydrogeologic parameters increases with
increasing heterogeneity. For example, an aquifer of extensive homogeneous
beach sand will require less investigation than a glacial unit consisting of
lenticular deposits of outwash sand and gravel interbedded with-clayey till.
Listed below are several hydrogeologic parameters that should be identified
for the aquifer system.12J
Hydraulic Conductivity: (distance/time) refers to the
ability of aquifer materials to transmit water, which in
turn controls the rate at which ground water will flow
under a given hydraulic gradient (discussed in Section
3.5.2). Hydraulic conductivity is controlled by the amount
and interconnection of void spaces within the aquifer which
may occur as a consequence of intergranular porosity,
fracturing, bedding planes, etc. Ground water, and hence
contaminants, have the potential-to move more rapidly in an
aquifer unit with a high hydraulic conductivity. Hydraulic
conductivity should be determined for each aquifer system
unit. In addition, hydraulic conductivities should be
determined on any semipermeable or confining beds present
in the subsurface, through which water may leak to or from
the aquifer. Methods of determining hydraulic conductivity
and considerations relative to this determination are
discussed below.
12J More information on determining aquifer characteristics can be found
in:
R. Freeze and J. Cherry, Groundwater (Prentice-Hall: Englewood Cliffs,
New Jersey, 1979).
G.P. Kruseman and N.A. De Ridder, "Analysis and Evaluation of Pumping Test
Data", International Institute for Land Reclamation and Improvement Bulletin
11, Wageningen, The Netherlands, 1979.
W.C. Walton, Ground-Water Resource Evaluation (McGraw-Hill: New York,
1970).
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OSWER Directive 9483.00-2
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Hydraulic conductivity can be determined in the field
using either single or multiple well tests. For units
having low hydraulic conductivity, single well tests
are generally used (i.e., a slug test). .In' evaluating
the accuracy or completeness of hydraulic conductivity
data, the applicant should be aware'that: (1)
hydraulic conductivity determinations based upon
multiple well tests are preferred; (2) multiple well
tests provide more complete information because they
characterize a greater portion of the subsurface; and
(3) the use of single well tests will require that
more individual tests be conducted at different
locations to adequately define hydraulic conductivity
variation across the site.
Single well tests, more commonly referred to as slug
tests, are performed by suddenly adding or removing a
slug (known volume) of water from a well and observing
the recovery of the water surface to its original
level. Similar results can be achieved by
pressurizing the well casing, depressing the water
level, and suddenly releasing the pressure to simulate
removal of water from the well. The vertical extent
of well screening will control the part of the
geologic formation that is being tested. The part of
the column above or below the screened interval that
has not been tested may also need to be tested for
hydraulic conductivity. Enough tests should be run to
provide representative measurement of hydraulic
conductivity and to document lateral variations of
hydraulic conductivity at various depths in the
subsurface.l1J
For hydraulic units having high hydraulic
conductivity, multi-well pumping tests are preferred.
Multiple well tests, more commonly referred to as
pumping tests, are performed by pumping water from one
well and observing the resulting drawdown in nearby
wells. Tests conducted with wells screened in the
same water-bearing formation provide hydraulic
conductivity data. Tests conducted with wells
screened in different water-bearing zones furnish
information concerning hydraulic communication.
Multiple well tests for hydraulic conductivity are
advantageous because they characterize a greater
11J Hydraulic conductivity information generally provides average values
for the entire area across a well screen. For more depth discrete
information, well screens would have to be shorter. If the average hydraulic
conductivity for a formation is required (for transport modeling), entire
formations may have to be screened, or data taken from overlapping well
clusters.
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OSWER Directive 9483.00-2
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proportion of the subsurface and, thus, provide a
greater amount of detail than single well tests.
Laboratory methods can be used to- estimate hydraulic
conductivity; e.g., hydraulic conductivity may be
determined on a core sample of the aquifer by using
either a constant-head or a falling-head permeameter.
However, ft»ld methods provide the best definition of
the hydraulic conductivity in most cases.
Heterogeneity in aquifer materials will cause
variations in hydraulic conductivity that" should be
evaluated and quantified. Additionally, hydraulic
conductivity may show variations with the direction of
measurement. This variation is termed anisotropy,
and, if present, the degree of it should be evaluated.
It is important that measurements define hydraulic
conductivity both vertically and horizontally across
the site. In assessing the completeness of hydraulic
conductivity measurements, the applicant should also
consider results from the boring program used to
characterize the site geology. Zones of high
permeability or fractures identified from drilling
logs should be considered in the determination of
hydraulic conductivity. Additionally, information
from boring logs can be used to refine the data
generated by single well or pumping tests.
Permeability: In the saturated zone, the permeability
(distance/time) of aquifer materials is directly related to
the hydraulic conductivity, and also describes the ability
of a medium to transmit fluid. Whereas the conductivity is
a function of the media and the fluid moving through it,
permeability is a function of the media alone (a function
of pore size). Knowing one of these parameters can lead to
the determination of the other. While the presentation and
accurate measurement of hydraulic conductivity data has
been suggested herein for inclusion in the variance
application, it may be useful to present permeability
values also. Permeability data may also play a role in the
transport modeling efforts of Chapter 5, and can be
determined in the field or laboratory.
Effective Porosity: If there are dead-end pores within
the ground-water system or ground water is for some reason
immobile, then the entire pore space (the total porosity)
is not effective in transmitting fluid and a correction to
the porosity must be made. This adjusted value of porosity
is called the effective porosity (dimensionless).
Effective porosity, therefore, refers to the amount of
interconnected pore space available for transmitting
water. In the laboratory, effective porosity can be
determined as the ratio of the volume of water yielded by
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gravity flow to the volume of soil or rock material. It
may be adequate to estimate this parameter by analogy with
other field results. Effective porosities should be
determined for each aquifer system unit.
Depending on the ground-water transport model that is chosen for use in
estimating exposure point concentrations (as discussed in Chapter 5), the
following parameters may also need to be measured or estimated:
Specific Yield/Storage: For unconfined aquifers,
specific yield expresses the volume of water that will
drain freely from an aquifer per unit area. For confined
aquifers, specific storage is the volume of water released
from, or taken, into, storage in the aquifer per unit area.
Field pump test methods are usually performed to estimate
these parameters. Storativity values or storage
coefficients can be calculated from these parameters.
Transmissivity: This parameter expresses the flow of
ground water over time through a specified areal section of
an aquifer. It can be estimated by multiplying the
hydraulic conductivity by the aquifer depth, or by the
analysis of field pump tests.
Attenuation Properties: If a ground-water transport
model is chosen that evaluates and computes mobility (e.g.,
retardation) or persistence (e.g., degradation),
attenuative properties of the aquifer materials should be
investigated. This investigation could include the
measurement of factors discussed above with respect to soil
attentuation, such as the organic carbon content of units
of the saturated zone. Values obtained or estimated for
such attenuation mechanisms should be presented in the
application along with a discussion of how they were
obtained and used.
* Dispersivity: The dispersivity or spreading of a
flowing substance due to the nature of the porous medium of
the aquifer materials may also need to be evaluated for
some transport models. The greater the dispersion, the
greater the dilution of a migrating contaminant. While
many models make general estimates of this process, some
may require more site-specific estimates of this
parameter. Dispersion would usually be estimated by
analogy, but can be determined from field tests.
For each of the parameters discussed in this section and presented for
inclusion in the variance application, the methods used to obtain the data
should be thoroughly discussed. A summary of the hydrogeologic properties of
each stratigraphic zone within the zone of saturation should be submitted by
the applicant. This summary should include a table that provides the aquifer
name, stratigraphic zone, and lithologic composition and values for hydraulic
properties measured (this section has stressed the measurement of hydraulic
conductivity and effective porosity). Additionally, these properties should
be discussed in regards to the ground-water regime as a whole.
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3.5.2 Ground-Water Flow Characteristics
The revised hazardous waste tank regulations state that the Regional
Administrator will consider in a variance application the potential adverse
effects of a contaminant release on ground-water and surface water quality,
taking into account the quantity and quality of ground water and the direction
of ground-water flow.1UJ The amount of ground water at a site and the
direction in which it flows are important factors to consider because they are
essential components of an analysis of the fate and transport of potential
contaminants in the ground water.
This section describes the determination and assessment of the site
characteristics with respect to recharge and discharge zones, ground-water
flow directions, ground-water flow rates, and other considerations associated
with these factors. In addition to the inclusion of maps and tables of
measurements as discussed in this section, the applicant should present a
thorough narrative discussion of investigative results identifying: (1) all
dominant ground-water flow directions, including both horizontal and vertical
components in upper and (significant) lower aquifers; (2) relationships of
flow to discharge or recharge areas; and (3) any temporal variations in
ground-water levels. As with other data identified in this chapter for
collection and presentation, ground-water flow characteristics are important
both in the understanding of a site's hydrogeologic setting and in the
determination of exposure point concentrations (see Chapter 5).
Recharge/Discharge Zones. To aid in the understanding of the ground-
water flow regime, and to aid in the identification of potential paths for
contaminant migration, the location of any proximate recharge or discharge
zones should be identified in the application. This identification is
determined in part by a site's location in the watershed. The applicant
probably does not need to quantify this information; rather, a general
indication of discharge or recharge characteristics could be presented.
For unconfined aquifers, recharge areas are usually topographic highs,
while discharge areas are topographic lows. Discharge/recharge areas also
indicate relative water cable depth. In discharge areas, the water table is
found close to or at the land surface, while at recharge areas, there is often
a deep unsaturated zone between the water table and the land surface. A
water-table contour map can be used to locate these areas.
Recharge and discharge in confined aquifers is more complex. Discharge
and recharge may occur where the aquifer outcrops. Some discharge may also
occur in the form of upward leakage in areas of upward hydraulic gradient.
Recharge can also occur by downward flow through the confining layer.
Ground-Water Flow Directions. The hydrogeologic field investigations
should include a program for precise monitoring of the ground-water levels,
including areal and temporal variations. This program will involve the
measurement of water levels in the observation wells installed for the purpose
1UJ Section 264.193(g)(2)(ii)(A) and (iii)(A) (51 Federal Register
25475, July 14, 1986).
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3-27
of investigating the saturated zone (as discussed in Section 3.5.1). Water
level data also are used to establish the depth to ground water at a site, as
well as in establishing hydraulic gradients and flow directions:
Some considerationsin the establishment and measurement of observation
wells (piezometers) include:
If che aquifer beneath a site is confined (i.e.,
upper boundary is of low permeability) and/or there
are significant lower aquifers, the elevation of water
levels (or potentioraeteric surfaces) in wells screened
to monitor such units should be measured. These
measurements require a larger number of wells (of
varying depths) than those necessary to examine a
single, shallow, unconfined aquifer.
Water-levels in piezometers should be allowed to
stabilize for a minimum of 24 hours after well
construction and development prior to measurement. In
low yield situations, a longer recovery interval may
be required.
Generally, water level measurements from boreholes,
piezometers, or monitoring wells used to examine the
same unit should have been collected within a 24-hour
period. This practice is adequate if the magnitude of
change is small over that period of time. There are
other situations, however, such as tidally influenced
aquifers or aquifers being actively recharged due to a
precipitation event, which necessitate that all
measurements be taken within a short time interval.
Parameters necessary to measure or ascertain in the determination of
ground-water flow directions include:
Deorh to Ground-water: Water level data should be
submitted with the application for each piezometer or
well. Data can be presented in tabular form and should
include well locations and identification, well depth,
screened interval, ground-water elevation, and sampling
date. Once established, the depth to the water table (for
unconfined aquifers) or ground-water depth should be
graphically shown for the site location. This
demonstration can be done by indicating the water table or
ground-water level on the stratigraphic maps used to
illustrate the relationship of subsurface materials to
ground water (as discussed in Section 3.3). Measurements
can be represented as the average depth to ground water at
a well point. If significant variations in levels occur
due to temporal factors (such as seasonal variations), it
will be important to present level measurements over time.
Potentiometric Surface: Using water level (hydraulic
head) distributions at the site, water level contour maps
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should be prepared. These contour maps should indicate the
tank(s) location, ground-water elevations, and isopaths
connecting elevations. Vectors indicating the direction of
flow should be added to these maps (from high head to low
head).'15- For sites with unconfined aquifers and no
underlying significant (interconnected) hydraulic units,
just one map, the water table contour map, needs to be
prepared. For sites with more than one aquifer unit,
contour maps of potentiometric surfaces (as determined from
piezometer measurements) for each lower unit of interest
need to be prepared. The degree of heterogeneity in
aquifer units will affect water levels or potentiometric
surfaces.
Hydraulic Gradients: Using the potentiometric surface
contour maps discussed above, hydraulic gradients (the
change in elevation of the water table over 'distance) can
be established. This determination will represent the
hydraulic gradient in the horizontal direction. Hydraulic
gradients should also be determined for any significant
lower units or confined aquifers.
Vertical Components of Flow: In addition to considering
the components of flow in the horizontal direction, the
applicant must assess the vertical components of
ground-water flow. This assessment may require the
installation of piezometers in clusters. A piezometer
cluster, or nest, is a closely spaced group of wells
screened at different depths to measure vertical variations
in hydraulic head. Placement of vertically nested
piezometers in closely spaced separate boreholes is the
preferred method, since information obtained from multiple
piezometer placement in single boreholes may generate
erroneous data.1'- Collected piezometric data should be
submitted with the application in tabular form for each
well nest, including well locations and identification,
well depth, screened interval, ground-water elevation, and
sampling date. Determinations of vertical flow gradients
should be made from the piezometric measurements, which can
aid in determining discharge and recharge zones, and
aquitard characteristics. The measurements of hydraulic
heads from these nested piezometers can be used to
construct flow nets (a vertical cross section of the site
1SJ The applicant should be aware that the determination of horizontal
flow directions may be inaccurate if water level countour maps are constructed
using wells or piezometers at different depths.
l*J Piezometer measurements should be determined along a minimum of two
vertical profiles across the site. These profiles should be cross sections
roughly parallel to the direction of ground-water flow indicated by the
potentioraetric surface maps.
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OSWER Directive 9483.00-2
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illustrating a. pattern (or flowlines) of hydraulic heads).
The use of flow nets can aid in the determination of
vertical flow gradients. All calculations and assumptions
should be described in detail.
Ground-water Flow Rates. The applicant must provide in the variance
application an assessment of ground-water flow rates or velocities beneath a
site. Along ivith flow direction, this assessment is one of the most important
pieces of hydrogeologic information supplied in the variance demonstration.
Methods for determining flow rates are discussed below.
Field Determination of Flow Rates: Field techniques for
the measurement of the rate of ground-water flow, -such as
tracer tests, are difficult to perform and will probably
not be necessary to conduct. Rather, information obtained
from analysis of the hydrogeological properties and flow
directions (hydraulic gradients) will allow the calculation
of ground-water flow velocity by a simple modification of
Darcy's law as discussed below.
Calculations of Flow Rates: Darcy's law is based on
empirical evidence that the flux water through an aquifer
is proportional to the hydraulic gradient. The constant of
proportionality is the hydraulic conductivity. The flux of
ground water flowing through an aquifer can be calculated
using the following equation:
V = -K i
where
V = the flux (or quantity) of water flowing
through a cross-sectional area (distance/
time)
K = hydraulic conductivity (distance/time)
i = hydraulic gradient (distance/distance) or
loss of head per unit length of flow
Ground-water flux values can be used to determine
quantities of ground-water discharge, and can also be used
to obtain velocity values for the rate of ground water
moving through the pore spaces of the aquifer:
V1 = V
n
where
V = average linear pore water velocity of ground
water (distance/time)
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n = effective porosity of the aquifer (dimensionless)
e
All calculations and assumptions used in the determination
of flow rates should be included in the application.
Other Considerations for Assessing Ground-Water Flow Characteristics.
Factors such as hydrologic fluctuations (e.g., seasonal variations, well
pumping, and tidal processes), low or high gradients, and aquifer
heterogeneity and anisotropy can result in variations in ground-water levels
and flow patterns, and can make the accurate determination of ground-water
flow difficult. Consideration of these factors is more-important at sites
with low hydraulic gradients. A program undertaken to investigate ground-
water flow patterns at a site should identify and assess any processes that
contribute to or affect ground-water patterns below the site. If these
processes are not evaluated, the uncertainty introduced by neglecting them
should be estimated. Several of these considerations are discussed below:
Seasonal Variations: Seasonal variations in ground-water use and
recharge can cause significant changes in ground-water flow
directions. In extreme situations, a flow reversal can occur. For
sites where this phenomenon may be important, water table or
piezometric surface maps should be submitted that represent yearly
averages and the two seasonal extremes. In addition, the applicant
should provide information describing the temporal changes in
ground-water flow direction using records compiled over a period of
no less than one year. Seasonal variations in flow direction are
more likely to occur in unconfined systems.
Pumping: Off-site or on-site well pumping may affect the
direction of ground-water flow. Municipal, industrial, or
agricultural ground-water use may significantly change ground-water
flow patterns and levels over time. Pumpage may be seasonal or
dependent upon water use patterns. Water level measurements in
piezometers must have been frequent enough to detect such water use
patterns. For sices where such variations occur, the rate of
ground-water withdrawal in the vicinity of the facility should be
summarized in tabular form and include well location, depth, type of
user, and withdrawal rates. The zone of impact created by any major
well or well field withdrawal should be identified on a good site.
map. The map should include modeling of drawdown curves.
Tidal Processes: Natural processes such as riverine, estuarine,
or marine tidal movement may result in variations of well water
levels. An applicant should document the effects of such patterns.
Gradient Considerations: In areas of low or flat horizontal
gradients, small errors in water level measurements or small
transient changes in water levels can make determination of flow
direction and rates unreliable. Determination of flow patterns is
also difficult where high or steep vertical gradients exist (often in
surficial units). Often, a near-surface, shallow water table aquifer
may overlie an aquifer of higher permeability, resulting in vertical
head gradients.
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Aquifer Heterogeneity: The degree of heterogeneity in aquifers
may range from fairly moderate to extreme. Because the
potentiometric surfaces, or water levels, in heterogeneous aquifers
are noc smooth, regular surfaces, determination of ground-water flow
patterns is difficult. At the contact between two geologic
materials, the hydraulic gradient will be discontinuous. For some
aquifers, such as fractured rock and karst aquifers, the
heterogeneity is much more complex.
Anisotropy: Anisotropy is the dependence of a property on
direction. Many aquifers display a horizontal.-vertical anisotropy.
Aquifers that may demonstrate anisotropy include aquifers in fluvial
sandstone, fractured rocks, or steeply inclined st-rata. Ground-water
flow direction and rates are difficult to determine from water level
data in these types of anisotropic aquifers. The dependency of
hydraulic conductivity on the degree of anisotropy has been discussed
previously.
The hydrologic fluctuations and other factors discussed above that make the
determination of flow patterns unreliable can often be overcome by an expanded
effort in water level monitoring. For seasonal variations in water levels, a
higher frequency monitoring schedule is necessary. For low horizontal
gradients, the effects of short-term changes in water levels can be analyzed
by installation of continuous recorders in selected wells. In aquifers having
significant vertical gradients, piezometers completed at various depths may be
required in order to provide a three-dimensional description of the flow
field. For heterogeneous and anisotropic aquifers, more water level
monitoring wells and more field tests for hydraulic properties are required.
3.6 SURFACE WATER CONSIDERATIONS
An important part of assessing exposure to releases is the identification
of surface water bodies chat have the potential to be contaminated by a
release from the applicant's tank system(s). This identification is also an
important feature of the revised hazardous waste tank regulations, in that the
Regional Administrator will consider the proximity and withdrawal rates of
ground-water users (as discussed in Chapter 4) and the proximity of the tank
system to surface waters (discussed here), in evaluating a secondary
containment variance demonstration.17-1
Proximity to Surface Water. At a minimum, all surface waters within
approximately five kilometers downgradient or downstream of the facility
should be considered when preparing a variance application. Professional
judgment, however, should be exercised in determining if surface waters beyond
this distance should be included. For example, if the ground-water velocity
is high in the vicinity of the facility, surface water well beyond five
kilometers may need to be considered. Also, if a reservoir used for drinking
water is beyond five kilometers away, but is fed by a stream or river that
flows near the facility, it should be included in the variance application.
ITJ Sec. 264.193(g)(2)(ii)(B) and III(c) (51 Federal Register 25475,
July 14, 1986).
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To summarize proximate surface water, the applicant should provide a map
of the facility and the surrounding area. The map should be appropriately
scaled and include contour lines to show the topography of the land. On this
map the facility and all surface water bodies within five kilometers
downstream or downgradient should be identified, including the following water
bodies:
screams;
rivers;
lakes;
ponds;
estuaries;
marine waters; and
wetlands (e.g., marshes, swamps, bogs, etc.).
All potential runoff or drainage pathways (e.g., ditches, sewers) from the
facility to surface waters should also be marked and identified on the map.
This information can often be obtained from U.S.G.S. topographic maps. As
discussed in Section 3.3.2, the topographic map prepared for inclusion in the
variance application can also be used to depict this information. In addition
to this map, the applicant should create a table that lists each surface water
body, the corresponding shortest distance from the facility to the surface
water body, and available information on the potential means of contamination
(i.e., ground-water discharge and/or surface runoff fed by previously
contaminated water). The surface water bodies should be listed in order from
shortest to longest distance from the tank.
Surface Water Characteristics. In. addition to identifying the physical
proximity of surface water bodies to the facility and estimating the travel
time of releases (discussed in Chapter 5, Exposure Point Concentrations), the
physical characteristics of surface water bodies may need to be investigated
if the applicant is to further consider dilution and transport within surface
waters (i.e., use surface water dilution to demonstrate no substantial hazard),
This investigation will be important for applicants whose tank system(s)
could, in the case of a leak, provide direct releases to surface water, and
can also be important for sites where the ground water directly feeds surface
water bodies. Once obtained, these parameters can be used to estimate
hazardous constituent transport within surface waters and the dilution
potential and mixing mechanisms of each type of surface water. This
information will likely be used in the estimation of exposure point
concentrations (as disccused in Chapter 5) and possibly in preparing an
environmental impact evaluation (see Chapter 7).
For all surface waters that potentially could be contaminated by a
release, the applicant should provide a description of appropriate physical
characteristics, such as:
surface area;
mean depth;
volume or cross-sectional area;
turbidity;
reaeration rate;
temperature patterns; and
hydraulic residence time or flow rate.
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OSWER Directive 9483.00-2
3-33
In addition, for estuarine and marine waters, tidal periodicity and amplitude
should be identified. For streams and rivers, flow rate information should
include: (1) average flow; (2) lowest flow that would be expected to occur
during a continuous 7-day period, once every 10 years; and (3) lowest recorded
flow rate. These parameters are less difficult to obtain than many of the
previously discussed hydrogeologic parameters and are not discussed in detail
here.l'J
IIJ Numerous references are available on methods characterizing surface
waters including:
Ven Te Chow, Open-Channel Hydraulics (McGraw-Hill: New York, 1959).
Ven Te Chow, ed., Handbook of Applied Hydrology (McGraw-Hill: New York,
1964).
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OSWER Directive .9483.00-2
CHAPTER 4
SURROUNDING LAND USE, WATER USE,
AND WATER QUALITY CHARACTERISTICS
This chapter presents guidance on identifying and obtaining relevant
information on surrounding land use, water use, and water quality
characteristics. Specifically, this chapter presents guidance on obtaining
and presenting the information necessary to comply with Sections
264.193(g)(2)(ii),(iii), and (iv) of the RCRA hazardous waste tank regulations
(51 Federal Register 25473, July 14, 1986). These sections require the
applicant to consider the potential adverse effects of a release on
ground-water quality, surface water quality and surrounding land. The
applicant must take into account the following factors:
quantity and quality of ground water (Sec.
264.193(g)(2)(ii)(A)and Sec. 264.193(g)(2)(iii)(E));
proximity and withdrawal rates of ground-water users
(Sec. 264.l93(g)(2)(ii)(B));
current and future uses of ground water in the area
(Sec. 264.193(g)(2)(ii)(C));
current and future uses of surface waters in the
area (Sec. 264.193(g)(2)(iii)(D));
current and future uses of the surrounding land
(Sec. 264.193(g)(2)(iv)(B)); and
existing quality of ground water (Sec.
264.193(g)(2)(ii)(D)).
These factors can be grouped into three general categories: ground-water
use and quality characteristics, surface water use and quality characteristics,
and surrounding land use characteristics. Accordingly, this chapter is
organized into three basic sections. Section 4.1 discusses ground-water use
and quality characteristics, Section 4.2 discusses surface water use and
quality characteristics, and Section 4.3 discusses surrounding land use.
Within each section, the type of information that the applicant will be
required to obtain is presented first, followed by a brief discussion of
potential information sources, suggestions for presenting the information, and
how the information will be used in the risk assessment process.
Exhibit 4-1 provides a general overview of the information gathering steps
described in this chapter. This chapter presents separate discussions of the
information needed to characterize ground-water and surface water use and
quality and surrounding land use; however, use of ground water, surface water,
and surrounding land are interrelated (e.g., use of ground water for
irrigation is likely to occur in arid agricultural areas where surface water
sources are not readily available). In addition, uses of surface water and
ground water depend in part on water quality (e.g., ground water in the area
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OSWER Directive 9433.
Exhibit 4-1
OVERVIEW OF PROCESS TO CHARACTERIZE
SURROUNDING LAND USE, WATER USE, AND WATER QUALITY
SECTION 4.1
Ground Water Use and Quality
Characterisitics
Proximity and withdrawal rates
of ground-water users (current
uses of ground water)
Existing quantity and quality
of ground water
Future uses of ground water
SECTION 4.2
Surface Water Use and Quality
Existing quality of surface water
Current uses of surface water
Future uses of surface water
SECTION 4.3
Surrounding Land Use
Current uses of surrounding land
Future uses of surrounding land
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OSVER Directive 9483.00-2
4-3
may not be of sufficient quality to be used for drinking purposes).
Therefore, although this chapter provides a sequential discussion of
ground-water quality and use, surface water quality and use, and surrounding
land use, in practice it will probably be necessary for the applicant to
obtain some information in all three of these areas before completing an
evaluation of any one particular area.
Not all of the water quality, water use, and land use parameters discussed
in chis chapter will need to be characterized at all sites.- The applicant
should exercise professional judgment, given the general guidelines presented
in this chapter, in determining precisely which water use and water quality
parameters are relevant for the facility, and in determining the level of
detail necessary to adequately support the risk-based variance application.
Those qualified to exercise professional judgment, as the term is used in this
chapter, may include hydro legists, geohydrologists, environmental engineers,
sanitary engineers, and civil engineers.
4.1 GROUND-WATER USE AND QUALITY CHARACTERISTICS
Existing quality of ground water and current and future uses of ground
water must be considered by the applicant in evaluating the present and
potential hazard to human health and the environment posed by a release of
contaminants from a tank system. Characterizing existing quality of ground
water is an important task for two reasons. First, existing ground-water.
quality normally defines the baseline conditions for evaluating risks to human
health and the environment. Second, existing ground-water quality in part
determines current uses and affects future uses. In addition, determining
ground-water uses is an important initial step in identifying potential
exposure pathways.
This section is organized into four subsections. Section 4.1.1 discusses
the information needed to characterize the proximity and withdrawal rates of
current users. Section 4.1.2 provides guidance for determining che existing
quantity of ground water in the area. Section 4.1.3 provides guidance for
assessing the existing quality of ground water, and Section 4.1.4 provides
guidance for identifying future uses of ground water.
4.1.1 Proximity and Withdrawal Rates of Ground-Water Users
The proximity and withdrawal rates of ground-water users are important
factors in determining the potential adverse effects of a release on human
health and the environment. The proximity of ground-water users will affect
both the time it takes a contaminant to reach the user and the concentration
of contaminants in the user's ground water. The withdrawal race (i.e., the
daily or annual volume of water pumped from an aquifer) is used to assess the
total amount of contaminants .the user is exposed to and, in some cases, any
influence the rate has on the direction and magnitude 'of ground-water flow in
an area.
For each ground-water user identified in the surrounding area, the
following information should be provided:
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OSWER Directive 9483.00-2
4-4
well location and distance from potential release
source (i.e., tank system);
well depth;
type of user:
potable (municipal and residential),
domestic non-potable (e.g., lawn watering),
industrial,
agricultural,
artificial recharge1-1 ; and
withdrawal rates (peak, annual, and seasonal).2-1
The above information can be presented using a map and an accompanying summary
sheet. Worksheet 4-1 can be used as a summary sheet.
Possible sources for information relating to proximity and withdrawal
rates of ground-water users include local and regional water districts or
companies, state agencies, federal agencies (EPA, U.S. Geological Survey, U.S.
Department of Agriculture) and various state, federal, and private
organization data bases. A detailed list of these information sources is
contained in Appendix B of this document.
4.1.2 Existing Quantity of Ground Water
The existing quantity of ground water is an important factor in evaluating
any potential risks to human health or the environment that could result from
a tank release. The existing quantity of ground water may affect the degree
of dilution of a release into ground water and subsequent migration of the
contaminant plume. In addition, the quantity of ground water affects the
potential yield of the aquifer and any potential future uses of the ground
water in the area for domestic, industrial, or agricultural purposes.
It is difficult to determine precisely a single value for the quantity of
ground water in the area. The quantity of water stored in an aquifer may vary
from season to season and from year to year. Aquifers are generally moving
reservoirs of water rather than static water resources and, therefore, the
total quantity of ground water stored or traveling through the facility
IJ Although artificial recharge wells (i.e., wells used to inject water
into an aquifer) do not actually constitute a "use" of ground water, they do
affect the geohydrological characteristics of an aquifer (i.e., magnitude and
direction of flow) .and could affect the environmental transport of
contaminants.
2J Seasonal withdrawal rates would apply to uses of ground water that
vary significantly throughout the calendar year. For example, agricultural
use would generally be confined to the growing season. In such cases, a range
of withdrawal rates and the average withdrawal rate for in season and out of
season use should be provided.
-------
WORKSHEET at ion
'100 250
\ . »400 800
250
From May tint
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OSWER Directive 9483.OQ-2
4-6
vicinity is time dependent. To assess ground-water quantity, the aquifer
yield should be characterized and discussed. Most of the hydrogeological data
necessary for characterizing aquifer yield will already have been collected as
part of the hydrological characterization performed as discussed in Chapter 3.
Yield is an important factor for evaluating the development and utili-
zation of ground-water resources. Generally, the development and utilization
of ground-water resources is controlled such that the annual volume of water
withdrawn from an aquifer does not exceed annual replenishment to the aquifer
(otherwise the aquifer's water supply would be depleted). The yield provides
an indication of the quantity of water than can be withdrawn annually and the
total quantity of water stored in the aquifer. To characterize the yield of
the aquifer underlying the facility, the following estimates of yield should
be provided.JJ
Safe yield: the quantity of water that can be
withdrawn annually without the ultimate depletion of
the aquifer.
Maximum sustained yield: maximum rate at which
water can be withdrawn on a continuing basis from a
given source.
Permissive sustained yield: maximum rate at
which withdrawals can be made legally and economically
on a continuing basis for beneficial use without the
development of undesired.results.UJ
Maximum mining yield: total storage volume in a
given source which can be withdrawn and used.
Permissive mining yield: maximum volume of water
which can be withdrawn legally and economically, to be
used for beneficial purposes, without causing an
undesired result."J
These estimates will be useful in assessing the productive capacity of the
aquifer for future ground-water uses. The applicant should first contact
state planning agencies for these estimates. Planning agencies will likely
have these estimates for use in ground-water resource planning. If these
estimates are not available they will need to be calculated from some of the
hydrogeologic data collected for Chapter 3. Vhile some of these calculations
JJ Source of definitions: John W. Clark, Warren Viessman, Jr. and Mark
J. Hammer, Water Supply and Pollution Control, 3rd ed. (New York: Harper &
Row, Publishers, 1977), p. 75.
*J Examples of undesired results include: increased energy costs by
lowered water levels; impairment of water quality; and infringement of rights
of other users.
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OStfER Directive 9483.00-2
4-7
are relatively straightforward,SJ a qualified professional will be needed to
derive the more complex estimates.
4.1.3 Existing Quality of Ground Water
The existing quality of ground water affects current and potential uses of
ground water and also provides a baseline for evaluating the incremental
potential human health and environmental risks due to a release of
contaminants from the tank system. The quality of ground water can be
affected by both naturally occurring sources, such as leaching of minerals
from the aquifer medium, and human sources, such as leaking of petroleum or
chemical products from underground storage tanks or the downward migration of
pesticides and fertilizers from agricultural areas. The primary purpose of
this subsection is to characterize the existing background quality of ground
water in the area (i.e., the quality of the ground water prior to a release-of
contaminants).
In evaluating the background water quality in the area, the applicant must
consider not only possible background concentrations of the selected indicator
chemicals, but also the background concentrations of other RCRA Appendix
VIII*J hazardous constituents. Existing contamination associated with
indicator chemicals or other RCRA Appendix VIII hazardous constituents may be
due to natural conditions in the area, prior releases from the hazardous waste
tank system, or prior releases from other sources in the surrounding area.
Assessing background concentrations of RCRA Appendix VIII hazardous
constituents is necessary to establish an existing baseline of environmental
contamination to which the incremental effects of a future hazardous waste
tank release can be added. For example, existing levels of contamination in
an area may be below a level at which significant risks to human health or the
environment would be expected to occur. Adding the contamination expected to
result from a tank release could, however, result in overall levels of
contamination above the significant risk threshold or above applicable
environmental standards, even if the tank release is not sufficient by itself
to pose a significant risk.
Measuring the ambient concentrations of every RCRA Appendix VIII hazardous
constituent is not generally feasible. To adequately assess background
ground-water quality, the applicant should attempt to identify other potential
release sources in the area (e.g., CERCLA sites, RCRA facilities, municipal
landfills, agricultural areas, or surface water dischargers) and identify
which RCRA Appendix VIII constituents are most likely to have been released by
each source. Some of the chemicals on the list of background chemicals may
also be indicator chemicals, particularly if the facility has experienced a.
prior tank system release. When determining which chemicals to include on a
list of background chemicals, the applicant need not include all the selected
indicator chemicals; only those indicator chemicals that are likely to be
*J For example, for an unconfined aquifer the maximum mining yield is
the product of the specific yield, the water table height, and the aquifer
area. For a confined aquifer the maximum mining yield is the product of the
specific storage, the hydraulic head, and the aquifer area.
SJ 40 CFR Part 261, Appendix VIII.
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OSVER Directive 9483.00-2
4-8
currently present in surrounding ground-water (i.e., if there is a suspected
human or natural release source) should be included on the background chemical
list.
For each chemical on the list of background chemicals, the applicant
should provide information on the concentration of the chemical in surrounding
ground water. As part of a RCRA Subpart F ground-water monitoring program (40
CFR 264.97-264.100}, some facilities may already have obtained data on
concentrations of hazardous constituents in surrounding ground water. These
historical monitoring data, if available, may be sufficient for assessing
background ground-water quality, provided that the data-are recent, are
derived using EPA-approved analytical procedures, and are from sampling points
relevant to a potential tank system release. It is important to note that- the
term "background concentration," as used in this document, has a different
meaning than when used in the RCRA detection and compliance monitoring
regulatory context. For the purpose of the risk-based variance, background
concentration .means existing ambient concentrations of chemicals in all
directions surrounding the facility and does not refer primarily to upgradient
concentrations of background chemicals. Consequently, historical monitoring
data for all wells, both upgradient and downgradient of the tank system,
should be submitted. If available, data for at least the previous two years
of monitoring should be submitted.
In cases where sufficient appropriate historical monitoring data are
unavailable, the applicant may need to install a ground-water monitoring
system or add to an existing system in order to adequately assess background
ground-water quality. Sampling of neighboring residential wells may also
provide useful data. Guidance on siting, constructing, and sampling
monitoring wells is provided in the RCRA Ground-Water Monitoring Technical
Enforcement Guidance Document (TEGD)~^Under RCRA Subpart F regulations
for solid waste management units (40 CFR 264.97), background concentrations
are usually determined based upon a full year of quarterly sampling of
monitoring wells. Given the 180 day time limit for completing the variance
application, however, it will not be feasible for applicants lacking
historical monitoring data to conduct a full year of sampling. Therefore,
background water quality should be determined based upon at least two separate
samplings of existing or newly installed monitoring wells and neighboring
residential wells, if feasible given the variance application time constraints
and the time required to analyze samples and interpret sampling results.
For facilities that have experienced a prior tank system release, the
applicant should also submit the results of any sampling or monitoring, or
hydrogeological investigations conducted in connection with the release (if
available) and should provide references to any reports submitted to the
Regional Administrator in connection with the release and in accordance with
the requirements of 40 CFR 264.196 (51 Federal Register 25477, July 14,
1986). Information on prior releases is important for two reasons. First,
prior releases contribute to the baseline level of environmental contamination
TJ EPA, RCRA Ground-water Monitoring Techriical Enforcement Document
(TEGD), Office of Solid Waste and Emergency Response, September 1986.
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OSWER Directive 9433.00-2
4-9
to which the effects of future releases will be added. Second, data on the
environmental fate and transport of hazardous constituents from prior releases
could prove very useful in predicting the migration of hazardous constituents
from future releases. In particular, historical data or hydrogeological
investigations documenting the magnitude and rate of migration of the
contaminant plume could be very useful in assessing the migration pattern and
risks of a future release.
Worksheet 4-2 provides instructions and a format for presenting the
necessary information on background ground-water quality_. The applicant
should provide information on the range and median of measured background
concentrations for each RCRA Appendix VIII constituent on the list of
background chemicals, distinguishing between upgradient data and downgradient
data. In addition to completing Worksheet 4-2, the applicant should also
submit supporting documentation of results including sampling logs, laboratory
analytical reports (including Quality Assurance/Quality Control documentation),
and chain of custody procedures. """
4.1.4 Future Uses of Ground Water
Although the ground water in the vicinity of the facility may not
currently be in use, the potential may exist for this ground water to be used
in the future. Future uses of ground water will be considered in evaluating
risks to human health and the environment (Chapter 5). For example,
contamination of an unused aquifer would generally not pose an imminent risk
to human health. If a local water utility is 'planning to utilize the aquifer
as a drinking water source in the future, however, then contamination of the
aquifer may pose a future risk to human health. In such a case, the nature
and magnitude of that risk would need to be discussed by the applicant in the
variance application. Several factors may influence the potential future use
of an aquifer or a portion of an aquifer. These factors include:
quality of ground water;
treatabilicy of ground water (if appropriate);
potential yield of ground water;
zoning or land use restrictions;
ground-water use restrictions; and
demographic factors (e.g., population growth).
Each of these factors is discussed briefly below.
The quality of ground water is an important determinant of potential
use. EPA has already developed some draft guidelines for evaluating potential
use of ground water based on ground-water quality. In general, water with a
total dissolved solids (TDS) concentration greater than 10,000 mg/1 is unsuit-
able for drinking purposes.1-1 Contamination of ground water caused by
either natural processes or human activity may preclude the use of the ground
IJ EPA, Guidelines for Ground-Water Classification under the EPA
Ground-Water Protection Strategy. Final Draft, Office of Ground-Water
Protection, December 1986, p. 39.
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WORKSHEET 4-2
MEASURED GROUND-WATER CONCENTRATION OF BACKGROUND CHEMICALS
INSTRUCTIONS :
1. List all solected back ground chemicals chemicals.
2. For each chemical listed. Identify the release source.
1. List the range of measured upqradieiit ambient concentrations and median
concentration-for each chemical.
4. Hat the range of measured downgradlent ambient concentrations and median
concentration for each chemical.
5. List the general or specific (If applicable) location of the sampling
polnt(s) used to determine the maximum measured concentration.
Facility ID:
Date:
Analyst:
Ity Control :
Mpgradlent Anlilent
Concentrations
Chemical
Trichloroethylene
Suspended a/
Release Source Range Median
b/
Prior facility release BDL BDL
1 of
Samples
6
Oowiigradlent Ambient
Concentrations
a/ 1 of
Range Median Samples
BDL- I. 8 ug/1 1.2 ug/1 3
Location of
. Maximum
Measurements
CM Monitoring Wells
12. 1, <
Comments
Release of 1,200
on B/5/BI
gallons
Arsenic
Naturally occurring
background
2-7 ug/1 3 ug/1
1-8 ug/1
3 ug/1
Prtvate'well at
Johnson Residence
Residence Is 2 km E of
facility
a/ If available, in some cases only a single data point may be available.
b/ BDL " Below detection limit*.
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OSWER Directive 9433.00-2
4-11
water for drinking water, agricultural, and industrial uses. If the ground
water in the vicinity is not already being used for drinking water, the
applicant has two options for determining whether water quality is sufficient
for drinking water use. One option would be for the applicant to assume that
the ground water is suitable for drinking water and attempt to demonstrate
that predicted levels of contamination would not pose a risk even if the water
were used for drinking. If the applicant suspects that the ground water is
unsuitable for drinking, then the second option would be for the applicant to
compare existing levels of background contaminant concentrations to available
drinking water standards and guidelines to determine the suitability of the
ground water for drinking water purposes. 'EPA's Office.of Drinking Water has
developed Primary and Secondary Drinking Water Standards and Health Advisories
for permissible concentrations of specific inorganic and organic contaminants
in drinking water. These standards are presented in Appendix C. EPA has also
developed health-based water quality criteria for surface waters under the
Clean Water Act. These criteria can be adjusted to apply to ground water by
factoring out ingestion of contaminated aquatic organisms. These adjusted
water quality criteria are also presented in Appendix C.
Worksheet 4-3 provides instructions and a format for comparing
ground-water quality to existing EPA standards relevant for determining the
suitability of ground water for drinking. The suitability of ground water for
agricultural and industrial uses will vary by industry and by type of
agricultural use. Consequently, professional judgment should be exercised to
determine the suitability of a ground-water resource for these uses. ' In some
cases, local agricultural extension service agents may be able to provide some
guidance .on suitability of ground water for agricultural use.
Treatability of ground water may, in some instances, be an important
consideration in assessing the potential future uses of a ground-water
resource. If the existing quality of ground water is sufficient for drinking
water use, the applicant need not evaluate treatability. If the existing
quality of ground water precludes the use of ground water for drinking water,
agricultural, or industrial use, however,-the applicant should evaluate
whether available treatment technologies could make such uses possible.
Available treatment technologies include carbon adsorption, ozonation, air
stripping, desalination, and ion exchange. A brief overview of treatment
technologies is included in Guidelines for Ground-Water Classification Under
the EPA Ground-Water Protection Strategy.9-1 Again, the applicant will need
to exercise professional judgment in evaluating the treatability of ground
water. Worksheet 4-4 provides a format and instructions for evaluating the
treatability of ground water.
The maximum sustained yield of an aquifer will also help determine
future potential uses of a ground-water resource. EPA's draft ground-water
classification guidelines estimate that a yield of 150 gallons per day is the
>J EPA, Guidelines for Ground-Water Classification under the EPA
Ground-Water Protection Strategy, Final Draft, Office of Ground-Water
Protection, December 1986. See Appendix E of this reference for a list of
recent papers and analyses of treatment technologies.
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WORKSHEET '1-3
COMPARISON OF BACKGROUND CHEMICAL CONCINIKAIIONS IN GROUND WATER TO DRINKING WATER STANDARDS AND GUIDELINES
INSTRUC]IONS:
1. List a I I background chemicals.
2. For each chemical, list the median and maximum ainlnont concentrations.
3. List any relevant EPA standards and the source of ihc standard
(i.e., MCL. MCLG. WQC).a/
14. Under the comments suction, indicate whether Urn background concentrations
exceed or Tall below the standards or whether no standards are available.
FaciIity ID:
Da it::
Analyst:
Quality Control:
Chemical
Cadmi urn
Toluene
Mod ian
Concentration
T00«4 mq/l
.2 mq/l
Maximum
Concentration
.00^ mq/l
1 mq/l
f(e lovant
LI'A Standard
.01 mq/l
15 mq/l
Source or the Standard
MCL. WQC
WQC
Comments
both values fall below the standard
both values Fall below the standard
a/ MCL = maximum contaminant level
MCLG = maximum contaminant level goal
WQC = water quality criteria
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WOUKSIIfir l|-ai ion
Carbon Adsorption
Air Stripping
301
501 .
As needcid
As needed
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OSWER Directive 9483.00-2
4-14
minimum yield necessary to meet the water needs of a typical household.lflj
Much higher yields would generally be required to support agricultural,
industrial, or municipal uses of ground water. In evaluating the quantity of
ground water in the area in Section 4.1.2, the applicant should have already
estimated the maximum sustainable yield of the aquifer. The applicant should
exercise professional judgment in determining what potential uses of ground
water can be supported by the potential yields of the aquifer.
In addition to hydrogeologic, physical and chemical ground-water
characteristics such as ground-water quality, potential yield, and
treatability, the applicant should also consider land use and ground-water
use restrictions and demographic factors in evaluating future uses of ground
water. State or community water laws may, for example, limit total withdrawal
from an aquifer or may place restrictions on the use of land overlying a
vulnerable aquifer. Regional and local zoning laws may also restrict or
control the use of land overlying an aquifer. Demographic factors, such as
population growth and housing patterns may also influence ground-water us.fi-. -
For example, if undeveloped land overlying an aquifer is zoned for residential
use, but the population in an area is projected to remain at existing levels,
future use of the ground water for residential drinking water may be
unlikely. Conversely, in areas undergoing rapid development, zoning patterns
may also change rapidly. Existing farmland may be developed for residential
or commercial use, with a possible subsequent change in ground-water use from
agricultural to domestic use.
It is' difficult to determine future use of -ground water with any great
certainty. State or regional water authorities, private and public water
supply system officials, and regional and local land use planning agencies may
be able to provide useful information. A narrative summary of future uses of
ground water should be submitted as part of the variance application. The
summary should demonstrate that the applicant has carefully evaluated the
future domestic, agricultural, or industrial use of the ground water and
should include a rationale and supporting evidence for rejecting or selecting
each future use.
4.2 SURFACE WATER USE AND QUALITY CHARACTERISTICS
Existing quality of surface water and current and future uses of surface
water must be considered by the applicant in evaluating the potential risks to
human health and the environment posed by a tank system release.
Characterizing existing quality and current and future uses of surface water
is required to: (1) establish the baseline background conditions for
evaluating risks to human health and the environment; and (2) determine water
uses for identifying potential exposure pathways in surface water. For
example, if a nearby lake is used extensively for swimming, the applicant
would need to consider the possibility of dermal contact exposures in
identifying exposure pathways in Chapter 5.
lflj EPA, Guidelines for Ground-Water Classification under the EPA
Ground-Water Protection Strategy. Final Draft, Office of Ground-Water
Protection, December 1986, p. 45.
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OSWER Directive 9483.00-2
4-15
In assessing surface water use and quality characteristics, the applicant
should evaluate those surface waters that might possibly be contaminated by a
release based on the hydrogeologic characterization discussed in Chapter 3.
For example, it is unlikely that surface waters upgradient and distant from
the facility would be contaminated by a release. The applicant should
consider the possibility of surface water contamination via both ground-water
flow and surface runoff.
As part of the Clean Water Act regulatory program, state environmental
agencies in many states may have already evaluated the existing quality of
surface waters in the area and evaluated current and future uses. Many state
environmental agencies have assigned "designated uses" to surface water bodies
in their state .as part of the process of developing water quality standards
under Section 303 of the Clean Water Act. "Designated uses" of.surface water
bodies include protection and propogation of fish, shellfish, and wildlife;
recreational uses; agricultural and industrial use; use as a public water
supply;- and navigational uses. A water body may have multiple designated
uses. In assigning designated uses to a surface water body, regulatory
agencies generally consider the highest attainable use to which a surface
water body could be put, taking into account existing water quality and the
potential for improving water quality. Therefore, designated uses may include
both current and potential future uses. The biological, physical, and
chemical data upon which designated uses are based are often contained in
specific documents referred to as "water body surveys and assessments." These
documents can be useful sources of surface water quality and use information.
An important first step in evaluating quality and uses of surface waters is to
contact the appropriate state environmental agency or Regional EPA office
responsible for water programs to identify and obtain any available
information on surface waters in the surrounding area.
The following subsections explain what types of information relating to
surface waters may be required and how this information may be used in
evaluating the quality of surface waters, identifying current uses, and
predicting future uses.
4.2.1 Existing Quality of Surface Water
Surface water quality parameters include both physical and chemical
parameters. Physical parameters of surface water quality, such as
temperature, turbidity, and reaeration rates will already have been measured
in evaluating the hydrogeologic characteristics of surrounding surface water.
Consequently, this subsection discusses the chemical parameters rather than
the physical parameters necessary to evaluate surface water quality.
- If available, the applicant should provide data for conventional surface
water quality parameters, such as suspended solids, nutrients (e.g., nitrogen
and phosphorous), sediment oxygen demand, salinity, hardness, alkalinity, pH,
fecal coliform, and dissolved solids. Data on these parameters may be helpful
in evaluating potential surface water uses. For example, highly saline water
may be unsuitable for drinking. In many cases, state or local environmental
agencies may already have obtained current data for these parameters for
specific surface water bodies. If such data are unavailable, water quality
testing will be required. The results of water quality testing should be
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OSWER Directive 9483.00-2
4-16
submitted in a clear, concise format along with necessary supporting
documentation.
For potentially toxic contaminants, the applicant should follow the same
basic procedure used for evaluating background ground-water quality. For each
surface water body "that could potentially be contaminated by a release,
concentrations of suspected RCRA Appendix VIII hazardous constituents should
be determined. Consideration should be given to both point sources and
non-point sources of contamination. The purpose of evaluating the
contamination from these sources is to establish a baseline for evaluating a
tank system release. For example, if existing discharges of contaminants into
a surface water body greatly exceed the projected discharge resulting from a
tank .system release, then the incremental risk posed by the tank release may
be negligible compared to existing conditions. Conversely, the same projected
tank release discharged into a pristine trout stream may be unacceptable. Any
point sources of pollutant loading to surface waters should be identified on
an appropriately scaled map. The point sources should include:
discharges from industrial facilities;
discharges from publicly owned treatment works (POTW); and
past waste discharges.
The applicant should submit a table, Worksheet 4-5, that includes the name
of each point source and the water body into which the point source
discharges. The National Pollutant Discharge Elimination System (NPDES)
permit number of each point source should also be included in this table. If
available, data on discharge rates, load allocations, permit discharge
conditions, and mixing zones should be provided and discussed in a separate
summary. Reports containing NPDES permit compliance and permit application
monitoring data should be referenced if these reports contain information on
the selected indicator or background chemicals.
Any non-point sources of pollution to surface waters that may affect the
variance decision should also be discussed. The permit applicant should
submit information on:
urban storm runoff;
agricultural runoff;
ground-water infiltration; and
other RCRA facilities.
Actual monitoring data may be submitted along with any contaminant load
calculations based on modeling results, if they are applicable. Worksheet 4-6
provides instructions and,a format of presenting the results of the background
surface water quality characterization.
.4.2.2 Current Uses of Surface Water
Surface waters have many potential uses and a particular surface water
body may have multiple uses. Important uses of surface waters include:
recreation (swimming, boating, and fishing);
protection and propagation of fish and other aquatic
life (including areas of special ecological concern);
protection ana propagation or risn ana otne
life (including areas of special ecological
-------
WOltKSMCCT 't-5
SURIAC.I WA1ER CON1AHINAHON SOURCES
INSTRUCT IONS:
1. List all potential contamination sources.
2. For each source list the water body into which 11 discharges.
3. If applicable and available, list discharge rate, contaminant
load allocations, and NPDES permit number.
Facility ID:
Oatu:
Analyst:
Qua Ii ty Control:
Source Water Uody
Oi srhar<|0
Rait; ml/day
Contaminant Load
Al locations
NPDES H
Comments
C and C Elcctroplat, Green River
Copper 20 q/day NJ50/2I
Zinc i|^ fl/day
SmithviMe POTW
Green River
1 §.JJWi ni /day
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WOHKSIIttI '1-6
HIASUItH) SUIUACI V/AIIK CONCENIRAI IONS Of BACKGROUND CHEMICALS
INSTRUCTIONS:
1. List all surface water bodies in the area th.u could potentially be containinoted
by a release.
2. For each water body list all selected background chemicals.
3. for each chemical listed, identify the release source.
l|. List the range and median measured ambient concentrations for each water body.
5. Identify the sampling location(s) used to determine the maximum concentration.
Facility ID:
Date:
Analyst:
Qua Iity Control:
Water Uody Chemical
Suspected Release Source
Location of
Ambient Concent rot ions Number of Maximum
Range Median Samples Measurement
Bear Creek Phenols
Zinc
Chemtron plant
fjafcural background
mg/l
1-6 mg/|
1.3 ing/I
2 mg/l
Samp I i uij
Samp I ing
Pt. ff2.
Comment
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OSWER Directive 9483.00-2
4-19
agricultural and industrial water supply; and
public water supply.
Identifying uses of surface water is an important initial step in
identifying potential exposure pathways and identifying potentially sensitive
ecological areas, such as fish spawning grounds or endangered species'
critical habitats. The information gathered on surrounding water use will be
helpful in making sure that the applicant does not overlook any potential
exposure pathways or sensitive aquatic environments.
To determine current uses of water, state and local government agencies,
such as water authorities, and natural resource management agencies should be
contacted. In remote areas, nearby residents may also be able to supply
useful information. If a surface water body has been assigned a "designated
use" the applicant should note the designated use or uses and determine which
of the designated uses are considered to be current uses. A list of potential
'sources for information on current uses of surface water is provided in
Appendix B. A summary of current uses should be provided on Worksheet 4-7.
4.2.3 Future Uses of Surface Water
Future uses of surface water depend not only on the hydrogeologic,
biological, and chemical characteristics of the surface water but also upon
legal and demographic factors. As in the analysis of future ground-water
uses, it can generally be assumed that current uses of surface waters will
continue in the future. For example, if a surface water body currently
supports recreational uses such as sport fishing and swimming, it is likely
that these uses will continue.
Physical, hydrologic, biological, and chemical characteristics all affect
the potential uses of a surface water body. For example, some species of
gamefish, such as trout, require fast moving relatively clear, cool water with
high concentrations of dissolved oxygen. Recreational uses of a surface water
body such as swimming and boating depend greatly on physical characteristics
such as tiepth, size, temperature, and water quality. EPA and many state
environmental agencies have already developed guidance on evaluating potential
uses of surface water bodies based on physical, chemical, and biological
characteristics. These guidance materials have been developed to support
state efforts to establish "designated uses" for surface water bodies under
the Clean Water Act. One useful document is the Technical Support Manual for
Conducting Use Attainabilty Analyses.*1J
While physical, chemical, and hydrologic characteristics of a surface
water body may determine what future uses are possible, demographic trends,
land use controls, government regulatory efforts and water use controls must
also be considered in identifying potential future uses. For example,
although existing water quality and physical characteristics of a surface
llj EPA, Technical Support Manual for Conducting Use Attainability
Analyses, Office of Water.
-------
WORKSIIEEI l|-7
SUMMARY 01 CUUHINI AND FUIURE USES OF SURIACE WATEHS IN 1HE AREA
INSIRUCTIONS:
1. List all surface water bodies that could potentially be contaminated by a release.
2. Provide a brief description of the water body (e.g.. lake, pond, reservoir).
3. For each water body, list the distance from the icloase source.
-------
OSVER Directive 9483.00-2
4-21
water body may support recreational use, if the water body is inaccessible and
removed from a population are-a, such use may be unlikely. Water usage laws
and restrictions may also place limits on the future use of a surface water
body for agricultural, recreational, or industrial purposes. Finally,
although existing water quality may not be sufficient for certain uses,
pollution reduction efforts or physical alterations to a water body, such as
dredging, may be planned or underway that could significantly affect future
uses.
An applicant should submit a narrative summary of current and potential
future uses of surface waters. For each surface water body identified in
Chapter 3, the applicant should provide a rationale and appropriate evidence
to support the use or uses identified for the particular water body. If a
surface water body in the surrounding area has been assigned a designated use
by the state or EPA, the applicant should indicate the designated use or uses
on Worksheet 4-7. If a surface water body does not have an assigned
designated use, the applicant should use the information provided in this
document and in available designated use classification guidance documents to
determine future uses. A summary table of current and future uses, as shown
in Worksheet 4-7, should be provided.
4.3 CURRENT AND FUTURE USES OF SURROUNDING LAND
To some extent, current and future uses of surrounding land will have
already been determined in identifying current and future uses of ground water
and surface water. The purpose of obtaining information on the current and
future uses of surrpunding land in this section is to characterize surrounding
agricultural, commercial, and residential land use and to identify any
ecologically sensitive areas that could be adversely affected by a release of
hazardous contaminants. Such ecologically sensitive areas may include:
state, federal, and local parks;
wildlife refuges;
wilderness areas; and
critical habitats for endangered and threatened species.
Agricultural, commercial, and industrial land uses can usually be
identified by contacting local land use regulatory authorities, such as zoning
boards, and reviewing appropriate land use plans and maps. Identifying
ecologically sensitive areas may be more difficult. While some of these
ecologically sensitive areas may be marked on U.S. Geological Survey
topographic maps or other maps, many may not be marked. In particular, the
location and boundaries of some critical habitats are not published or made
readily available to the public.
To verify the existence of ecologically sensitive areas and to identify
areas under consideration for protection, relevant state and federal
government agencies, such as state and federal park agencies, fish and
wildlife agencies, and private conservation groups, such as The Nature
Conservancy, should be contacted. A list of potential agencies and
organizations that may be able to provide information on surrounding land use
is included in Appendix B of this technical resource document.
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OSVER Directive 9483.00-2
4.-22
The applicant should submit a narrative description of current and future
uses of surrounding land. Information on land use collected to determine
future uses of ground water and surface water 'should be included. The use of
all land in the immediate surrounding area should be carefully described. For
each discrete parcel of land in the area, the applicant should describe
current use and potential future uses. The applicant should devote special
attention to describing any ecologically sensitive habitats in the surrounding
area. Two maps of the surrounding area, one identifying current land use and
another identifying future land uses, should also be provided.
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OSWER Directive 9483.00-2
CHAPTER 5
IDENTIFYING EXPOSURE PATHWAYS AND
ESTIMATING EXPOSURE POINT
CONCENTRATIONS
The applicant for the risk-based variance could demonstrate no substantial
hazard in one of two ways: (1) if current or future exposure pathways do not
exist; or (2) if current or future exposure point concentrations do not pose a
substantial hazard to human health or the environment. This chapter describes
methods for identifying current and future potential exposure pathways and
estimating potential environmental concentrations of indicator chemicals if
any exposure pathways exist. Because the applicant must assess the risk
associated with potential worst case releases, it is necessary to identify if,
how, and when exposure would take place. Environmental fate and transport
models1-1 are generally used for these determinations. Modeling may be
necessary to demonstrate that no exposure pathways exist (e.g., by showing
that attenuation mechanisms result in a situation such that contaminants never
reach points of human uptake (i.e., potable wells)). In some situations,
however, modeling will not be necessary. For example, a detailed hydrogeolgic
investigation and qualitative assessment of site conditions and exposure
pathways may be sufficient to demonstrate that no exposure pathways exist
(e.g., due to an impermeable subsurface formation preventing transport of
contaminants to ground water, and the location of the facility in an isolated,
naturally contained area (thereby preventing surface water contamination)).
Many models, ranging widely in sophistication, data input requirements,
cost, and reliability, are available. Consideration should be given to the
complexity of the site and the environment, the precision needed, and the time
available for analysis. Much literature exists which describes the various
available models and provides guidance in selecting modeling techniques that
are appropriate for site-specific conditions.2-1 It should be recognized
early, however, that the uncertainty associated with modeling results can be
significant. Thus, considerable expertise is frequently necessary to
interpret hydrogeologic and exposure assessment information.
At some sites, background chemical contamination is significant and must
be accounted for in the hazard evaluation. Background is defined here as
chemical contamination due to a source other than a release from the hazardous
waste tank system. Background can be either "natural," as in the case of
certain inorganics (e.g., arsenic), or from various anthropogenic sources
(e.g., industrial point sources, other uncontrolled waste sites, agricultural
1J For the purpose of this discussion, the term "model" refers to any
estimation technique; these techniques include simple equations as well as
complex computer programs.
IJ A current review of existing models can be found in the following
document: EPA, Superfund Exposure Assessment Manual, Draft, Office of
Emergency and Remedial Response, January 1986.
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OSWER'Directive 9483.00-2
5-2
pesticide applications). In either case, background concentrations,
determined in Chapter 4, must be added to the estimated exposure point
concentrations that would result from a tank release. As discussed in Chapter
4, it is important that background concentrations of chemicals that have not
been included as indicator chemicals, and that may not even be present in the
waste, be considered in the overall hazard evaluation. This inclusion is
necessary because the existing quality of the particular environmental media
being evaluated may be approaching or may have already exceeded the threshold
that determines whether the environmental media is posing a substantial
present or potential hazard to human health or the environment. Therefore, if
chemicals with high background concentrations were not included as indicator
chemicals, they must be included in the analysis at-this point. Although
sampling of soil, water, and air is essential in determining background
concentrations, information resources such as the U.S. Geological Survey, the
Soil Conservation Service, the Army Corps of Engineers, and state
environmental or land use agencies may also be helpful in providing data and
information on sources o-f background contamination.
The methods for estimating exposure point concentrations should be applied
to the selected indicator chemicals. Exhibit 5-1 diagrams the activities
involved in estimating exposure point concentrations. The first task is a
detailed exposure pathway analysis (Section 5.1). The second is estimation of
the highest short- and highest long-term concentrations for each indicator
chemical at each exposure point (Section 5.2). The concentrations derived
will then be the inputs to Chapters 6 and 7 (estimation of human hazard and
environmental hazard, respectively). Worksheets are provided as a means for
organizing and documenting the data collected for estimating exposure point
concentrations. Filling in these worksheets will not be .sufficient to
complete the quantitative analyses required. Rather, they serve to direct and
focus the analysis so that the results can be used directly in later steps of
the hazard evaluation. All procedures, assumptions, and calculations used to
develop concentration estimates must be clearly documented in a format that
will facilitate review.
5.1 IDENTIFY EXPOSURE PATHWAYS
This section describes an approach for identifying current and future
potential exposure pathways at a hazardous waste tank site.3J An exposure
pathway consists of five necessary elements:
(1) source (hazardous waste tank systems in this case);
(2) mechanism of chemical transport to the environment
(usually leaching and runoff, but often also
volatilization);
(3) environmental transport medium (e.g., ground water,
surface water);
3J Also, see the following: EPA, Permit Applicants' Guidance Manual
for Exposure Information Requirements Under RCRA Section 3019, Office of
Solid Waste, July 3, 1985.
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OSWER Directive 9483.00-2
Exhibit 5-1
OVERVIEW OF EXPOSURE POINT CONCENTRATION ESTIMATION
SECTION 5.1.1
Identify source (e.g.. underground tank), mechanism of potential
transport (e.g., leaching), and environmental transport'medium
(e.g., ground water).
SECTION S.I.2
Identify current and future potential exposure points (e.g., future
drinking water well at facility boundary, nearby wildlife habitat) and route:
of uptake (e.g., ingestion, dermal absorption).
SECTION 5.1.3
Integrate release sources, transport mechanisms and media.
and exposure points and routes, into exposure pathways.
Remove incomplete
pathways from
further
consideration.
Are there
any complete
pathways?
SECTTON 5.2
Yes
Use environmental fate
modeling to determine
exposure point
concentrations of indicator
and background chemicals.
Demonstration of
no substantial
hazard is complete.
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OSWER Directive 9483.00-2
5-4
(4) point of potential human or environmental contact with
the contaminated medium (i.e., the exposure point); and
(5) human or. environmental exposure route (e.g., drinking
water ingestion) at the exposure point.
Exhibit 5-2 illustrates the elements of an exposure pathway. Each pathway,
therefore, describes a unique mechanism by which a population, an individual,
a wildlife habitat, etc., is potentially exposed to contaminants originating
from a facility. The overall risks posed by a facility are a composite of the
set of individual pathway risks. Risks for individual pathways, however, may
not always be additive' because they may represent risks to different
populations (e.g., ground water may be used by one population while surface-
water is used by another).
The risk assessment process is based on concern for both current and
future risk to individuals, populations, and the environment. Therefore, two
exposure points that must be determined and evaluated are the geographic
points of highest current and highest future individual exposure for each
combination of release source, transport mechanism, and transport medium.
These exposure points will be the geographic locations where human or
environmental receptors are potentially exposed to the highest predicted
chemical concentrations. For the highest future exposure, the farthest point
from the tank system or cluster that can be considered is the particular
facility boundary that would result in the highest potential' future exposure,
unless it can be shown that future exposure would be higher outside the
facility boundary. To obtain a complete understanding of the potential risks
associated with a potential release, current and future exposure points with
lower exposure concentrations must also be evaluated. In summary, there are
essentially three types of exposure points:
(1) current locations of highest potential exposure (e.g.,
existing private wells near the site);
(2) future locations of highest potential exposure (e.g.,
hypothetical well on the facility boundary); and
(3) all other current and future potential exposure points
(e.g., existing distant wells used for a local
water-supply system).
To identify possible exposure pathways, current and future activity
patterns on and near the site should be defined and combined with chemical
release source and transport media information. This task is accomplished
using a qualitative, yet systematic, procedure that requires the judgment and
experience of professionals in fields such as public health and wildlife
biology. Because chemical transport is more rigorously analyzed for the
estimation of exposure point concentration phase of the exposure assessment
(Section 5.2), the initial list of exposure pathways can be modified as the
analysis proceeds. If there are questions or uncertainties about a possible
exposure pathway, it should not be eliminated from the analysis until the
exposure point concentration phase is completed.
-------
'>«
'«*>.,
<"*,
-------
OSWER Directive 9483.0'0-2
5-6
The analysis described here is a first-cut organization of the relevant
site information so that major exposure pathways can be defined. It is not
intended as a time-consuming task in the overall hazard evaluation process.
Modeling will help confirm the important exposure pathways (i.e., the exposure-
points with high exposure concentrations). The first three elements of the
exposure pathway analysis listed previously (i.e., source, transport
mechanism, and transport media) are discussed below in Section 5.1.1. The
lasc two elements of the exposure pathway analysis (i.e., exposure point and
exposure route) follow in Section 5.1.2. These five elements are then
integrated into exposure pathways in Section 5.1.3. Finally, Section 5.1.4
provides guidance on determining the presence of sensitive populations and
sensitive environmental receptors.
5.1.1 Determine Possible Chemical Release Sources, Transport
Mechanisms, and Transport Media
Possible release sources for a site are ruptures or leaks from the systems
or components' being considered for the risk-based variance from secondary
containment; the transport mechanisms are usually runoff, leaching, and
volatilization; and the four transport media are soil, surface water, ground
water, and air. Much of the information for release sources, transport
mechanisms, and transport media has already been gathered, as described in
Chapters 2, 3, and 4, and it may only need to be compiled here. In addition,
Exhibit 5-3 provides guidance on determining common release sources, transport
mechanisms, and transport media.
Use the first three columns of Worksheets 5-1 and 5-2 to summarize the
results of the initial release analyses. At this point, combinations of
release source, transport mechanism, and transport medium for a site (i.e.,
the first three components of an exposure pathway) have been identified. The
exposure points for each must now be determined.
5.1.2 Identify and Characterize Exposure Points and Routes
Again using Worksheets 5-1 and 5-2, identify the current location of
highest potential exposure to humans and the environment. These exposure
points may be either inside (e.g., workers) or outside (e.g., residential
area) the facility boundary. Next, identify the future location of highest
potential exposure. These locations will usually be at the facility, tank
system, or tank system component boundary. The farthest point, however, that
can be considered for future exposure is the particular facility boundary that
results in the highest potential individual future exposure, unless it can be
shown that future exposure would be higher outside the facility boundary.
This point will usually be the nearest downgradient boundary. Finally,
identify for each combination of release source, transport mechanism, and
transport medium all other current and future potential exposure points.
Consideration of all potential exposures in this way (i.e., highest
current, highest future, and all others) ensures that significant risks are
not ignored. For example, assume a facility does not have any current on-site
ground-water exposure points. If the facility boundary is not expected to be
a significant future ground-water exposure point (e.g., due to a thick layer
of rock overlying the aquifer), then off-site locations may provide the only
potential exposures. These off-site exposures may result in significant risk.
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OSWER Directive 9483.00-2
5-7
EXHIBIT 5-3.
COMMON RELEASE SOURCES, TRANSPORT MECHANISMS,
AND TRANSPORT MEDIA
Transport
Medium
Transport
Mechanism
Release Source
Surface Water
Ground water
Soil
Air
Surface runoff
Episodic overland
flow
Ground-water seepage
Site leaching
Site leaching
Surface runoff
Episodic overland
flow
Fugitive dust genera-
t ion/depos ition
Tracking
Volatilization
Fugitive dust
generation
Contaminated surface soil
Overflows, spills, leaks
Catastrophic release
Contaminted ground water
Leaking tank systems
Contaminated soil
Leaking tank systems
Contaminated surface soil
Overflows, spills, leaks
Catastrophic release
Contaminated surface soil
Contaminated surface soil
Overflows, spills, leaks
Catastrophic release
Contaminated surface soil
Contaminated wetlands
Contaminated surface soil
-------
WORKSHEET 5-1
I'OIINIIAl HUMAN EXPOSURE PATHWAYS
INSTRUCTIONS:
1. list all release sources, transport. inocli;im suib. nnd transport niodia
(use additional worksheets if necessary).
2. Describe the nature of the exposure point ;ind its location will)
respect to release source (e.g., nearest residence to volatilization
release site. JOO feet NH). Attach a map indicating location of
system and exposure points.
3. List exposure route (e.g.. inhalation, uujo&tion).
>i. Report the number of people potentially exposed at the exposure point.
5. Indicate If exposure pathways are complete (i.e.. where release source.
transport mechanism, transport medium, exposure point, and exposure
route all exist).
facility ID:
Cluster/lank System:
On us:
Analyst:
Qua Ii ty Control:
Release
Source
Underground
Tank" 1
Underground
Tank 1
Abuvo'i round
Pipes
Ong round
Tank 3
Transport Transport
Mechanism Medium
Leachino Ground water
Leach inq Ground water
Volat i 1 izat ion Air
Volatilization Air
Exposure
Point
V/el Is at nearest
residences
f aci 1 i ty boundary
( future)
Nearest residences
(includes day-care center)
Tra i ler park (0.5
miles south of site)
Exposure
Route
Ingesjion of
drinking water
lnqes(.ion of
drinking water a/
Inha la t ion
Inha lat ion
Size of
I'upttlat ion
50
? ( future )
50
600
Pathway
Complete?
Yes
Yes( future)
Yes
Yes
a/ Hydrogeologic investigation has determined that the ground water is potable.
-------
WORKSHEET 5-2
POIINIIAI INVIRONHENIAL RECEPIOR EXPOSURE PATHWAYS
INSTRUCTIONS:
t. List all release sources, transport mechanisms, and transport media
(use additional worksheets if necessary).
2. Describe the exposure point.
3. List the exposure route (ingestion, respiration).
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OSWER Directive 9483.00-2
5-10
The highest short- and highest long-term exposures must be considered for
each exposure point. (Short- and long-term are addressed in greater detail in
Section 5.2.) In addition, include any locations with the potential for
exposure of populations (e.g., public drinking water supplies, shopping
centers, industrial parks, wildlife refuges) or sensitive populations that may
be at special risk (e.g., schools, hospitals, endangered habitats).
(Sensicive populations are considered in greater detail in Section 5.1.4.)
Determine the number of people as well as the number and type of environmental
receptors (e.g., wildlife, habitats) potentially affected at each exposure
point and record the basis for the estimate.fcj Finally, determine the
probable routes of exposure at each exposure point (e.g., drinking water
ingestion, fish ingestion).
The distinctions between human exposure points and environmental receptor
exposure points are of critical importance. In particular, human exposure
points refer to locations of human activity, whereas environmental receptor
exposure points refer to wildlife and their habitats, agricultural products,
ecologically vital areas, historical sites, other human-made structures,
protected parklands, and renewable resources. Environmental receptors may
also include underground cables, septic fields, foundations or structures of
archeological or esthetic value which may come in contact with contaminated
water or vapors released from a contaminant plume. For the purpose of
identifying the potentially affected environmental receptor, a complete list
of species (plant and animal), population estimates for each species
(including migrants and threatened or endangered species), identification of
sensitive species (most sensitive to toxic action of chemicals), commercial- or
recreational value, of affected area over the total duration of exposure, and a
list of physical structures contacted should be included in Worksheet 5-2.
The species of wildlife present, and their numbers and interactions, will be
examined in more detail in Section 7.3.
Guidance for identifying exposure points and routes is given below for
each of the four transport medium. Typical exposure points and routes for
these media are summarized in Exhibit 5-4. This exhibit can be used as
guidance for determining exposure points and routes, but note that this
determination requires a site-by-site analysis and the possibility of other
exposure points and routes must be considered for each site.
Surface Water Exposure. The significant current and future potential
exposure points for surface water pathways depend on current and future
downstream uses of the water. Potential withdrawal points and areas of
in-stream use must be considered. Withdrawal points to be considered include
"J Although individual risk is of primary concern, the number of people
or environmental receptors is important for providing additional information
in "borderline" demonstrations. For example, if estimated individual
potential exposure through a public water supply is low but highly uncertain
due to complex exposure pathways, then the existence of a large potentially
exposed population may indicate the need for greater caution when deciding
whether to allow a variance. In the event exposure is underestimated, it
would be more difficult to provide an alternative water supply for a large
population than for a small population.
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OSWER Directive 9483.00-2
5-11
EXHIBIT 5-4
TYPICAL PRESENT AND POTENTIAL EXPOSURE PATHWAYS
Transport/Exposure
Medium
Typical Present or Poten-
tial Exposure Point
Major
Exposure Route
Surface water Withdrawal point for potable use
Withdrawal point for agricultural
Ground water
Soil
Air
use
Withdrawal point for other use
(e.g., industrial)
Nearest point for swimming/
contact sports
Nearest point for fishing
Aquatic habitat
Settling basins (on-site)
Potable well (private or
public)
Agricultural well
Well for other uses
(e.g., industrial)
Basement infiltration
Forage plants
Spring
On-site
Immediately adjacent to site
Nearest cropland
Nearest residence/habitat
Nearest population magnet (e.g.,
shopping center, school,
industrial park)
Other residence/population at
point of highest concentra-
tration
On-site
Ingestion, dermal,
inhalation
Ingestion (food),
dermal, inhalation
Dermal, inhalation
Ingestion, dermal
Ingestion (food)
Ingestion/respiration,
dermal, food chain
Ingestion, dermal, in-
halation (wildlife)
Ingestion, dermal,
inhalation
Inhalation, inges-
tion (food),
dermal
Inhalation, dermal
Inhalation
Ingestion, food chain
Ingestion, dermal, in-
halation
Dermal, ingestion
Dermal, ingestion
Ingestion (food)
Inhalation
Inhalation
Inhalation
Inhalation
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OSWER Directive 9483.00-2
5-12
domestic water supply (e.g., water used for drinking, cooking, and bathing),
agricultural use (e.g., livestock watering, irrigation), wildlife use, and
industrial use. Relevant in-stream uses include swimming and other water
contact sports, private and commercial fishing (resulting in ingestion of
contaminated fishl, and wildlife use. Sources for identifying withdrawal
points and uses include the following:
site vicinity surveys;
state water agency records (including Clean Water
Act "designated use" documentation for each surface
water body);
local water utility records;
withdrawal permits; and
EPA Office of Drinking Water data bases (e.g.,
Federal Reporting Data System).
Locate on a map the exact points of potential withdrawal and in-streara use in
relation to the source from topographic maps.
At some sites, an important potential route of exposure via surface water
is through the ingestion of contaminated fish or shellfish. Fish living in
contaminated water can concentrate some contaminants from the water in their
tissue. Due to the solubility of some contaminants in fats (e.g., PCBs), many
chemicals are bioconcentrated and appear in the tissue at concentrations
higher than in the surrounding water. Consumption of fish from surface water
near sites may, therefore, be a significant potential human or wildlife
exposure route.
Ground-Water Exposure. Determining points of current and future
potential exposure to ground-water contaminants may require subsurface flow
modeling. In general, nearby wells will have higher concentrations than
distant wells, and downgradient wells will have higher concentrations than
upgradient wells. Consideration must also include hydraulic connections
between ground water and the identified surface water exposure points.
Locations and depths of public water supply wells, domestic wells,
agricultural wells, and industrial wells must be determined. In addition, any
other relevant ground-water uses must be identified. Potential sources of
well information include the following:
site vicinity surveys;
state or local agency well logs;
EPA Office of Drinking Water; and
U.S. Geological Survey (USGS).
If comprehensive ground-water modeling is planned, do not determine the
significant exposure points until the modeling is completed. The modeling
results can then be used to determine the significant exposure points (i.e.,
exposure points with high concentrations).
Soil Exposure. Areas of highest current and future direct exposure to
contaminated surface soil will generally be on or directly adjacent to the
site. If access to the site is not restricted, the site itself must be
assumed to be the point of highest exposure to surface soil. If site access
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OSWER Directive 9483.00-2
5-13
is limited (e.g., fencing and deed restrictions), the significant exposure
point for soil often will be the nearest facility boundary, although wildlife,
especially birds and flying insects, may still be exposed to high
concentrations within the facility boundary.
Direct human exposure is from soil that is transferred to the mouth by the
hands and wind. Wildlife also ingest and inhale soil particles. Dermal
exposure may also be significant. A possible indirect route of exposure from
soil contamination is chemical uptake by plants, with subsequent ingestion by
humans or wildlife. As for the other exposure pathways., future potential
exposure points (e.g., on site) and current potential exposure points (e.g.,
nearest residence) must be considered.
Air Exposure. For current and future potential air exposures, only
systems containing highly 'volatile waste will generally be of concern. For
aboveground or onground systems, secondary containment reduces direct air
exposure risks by reducing the surface area of~Volatile waste exposed to air.
For inground or underground systems, secondary containment reduces indirect
air exposure risks by reducing contaminated ground water flowing or being
pumped to the surface, infiltrating into basements, or being used for
showering, bathing, etc.5j
The individual or population potentially exposed to the highest direct
air concentrations will generally be located downwind of and nearest to the
source; however, this is not always the case. For example, the point of
highest ambient ground-level concentration may be some distance from the
source if the source is elevated. In these more complex situations, the
appropriate exposure point must be determined in conjunction with air modeling
efforts (as described in Section 5.2). The individual or population
potentially exposed to the highest indirect air concentrations must be
determined on a site-specific basis.
Once the future populations are determined, it is relatively
straightforward to locate the closest existing population exposed to air
releases. These populations can be located in residential, industrial,
commercial, or undeveloped areas, or at other points of human activity.
Potential sources of this information include the following:
site vicinity surveys;
topographic maps;
aerial photographs of the site;
county or city land-use maps; and
census data.
SJ Recent studies indicate that exposure of volatile chemicals due to
showering in contaminated water may be greater than exposure from drinking the
contaminated water. For a reference list and recent review, see the
following: Foster, S.A. and Chrostowski, P.C., Integrated Household Exposure
Model for Use of Tap Water Contaminated with Volatile Organic Chemicals,
ICF-Cl'ement Associates, Inc., Washington, DC, June 1986.
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OSVER Directive 9483.00-2
5-14
On a map, indicate precisely for each air release source the direction and
distance to the significant exposure point. Again, one must determine future
potential exposure points as well as current potential exposure points.
The point of highest direct short-term individual exposure by air may
well be different from the point of highest long-term exposure. The highest
direct short-term exposure point will generally be the closest potential
population in any direction from the site, whereas the highest direct
long-term exposure point will, in most cases, be downwind. Therefore, select
the exposure point for determining long-term concentration within the downwind
90° arc from the emission source (45? on each side of the average downwind
centerline as determined from historical wind data for locations near the
site), unless it can be demonstrated that long-term concentrations will be
higher elsewhere. These determinations often require site-specific data. In
many cases, historical wind data for airports- and other locations may be
used. One source of this information is the National Oceanic and Atmospheric
Administration (NOAA).
5.1.3 Integrate Release Sources, Transport Mechanisms and Media, and
Exposure Points and Routes into Exposure Pathways
Examine the information developed in the previous two steps and determine
the complete exposure pathways that exist for the site. Use Worksheet 5-1 to
identify complete exposure pathways. A complete pathway is one that has all
the necessary components: a source of chemical release, a transport
mechanism, an environmental transport medium, a potential human or
environmental receptor exposure point, and a likely route of exposure. For
example, if there is no current ground-water use, then the current exposure
pathway is incomplete. But, if the ground water is potable, then the future
exposure pathway is complete. The exposure points for the complete exposure
pathways define the spatial locations at which chemical concentrations must be
projected. The health and environmental hazard evaluations developed in
Chapters 6 and 7 are based on exposures at these locations.
In some cases, exposures via identified pathways may be non-quantifiable.
There are a number of possible reasons for this, including the absence of
adequate models on which to base estimates of chemical releases, environmental
concentrations, or human intakes. If an exposure pathway is determined to be
non-quantifiable during the exposure assessment procedure to follow, continue
to include it as a potential pathway on all subsequent worksheets, designating
it as non-quantified. This information can be taken into account in
assessments of the uncertainty of the results.
5.1.4 Determine Presence of Sensitive Populations and Environmental
Receptors
Review the information on the site area and identify any human
populations or environmental receptors with high sensitivity to chemical
exposure. Sensitive subpopulations that may be at higher risk include infants
and children, elderly people, people with chronic illnesses, sensitive
wildlife habitats, and endangered species. Generally, it must be assumed that
these subpopulations are present, but any readily identifiable sensitive
subpopulations should be noted.
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OSWER Directive 9A83.00-2
5-15
To identify sensitive subpopulations on or near the facility, determine
locations of schools, day care centers, hospitals, nursing homes, retirement
communities, sensitive wildlife habitats, and endangered species that are
potentially affected. Use local census data and information from local public
health and wildlife officials for this determination. Record this information
on Worksheets 5-1 and 5-2.
5.2 ESTIMATE EXPOSURE POINT CONCENTRATIONS
This section provides guidance on estimating exposure point
concentrations of indicator chemicals.*-1 At this point in the variance
application, there are three possibilities concerning expos-ure pathways: (1)
no current or future exposure pathways exist; (2) a current or future pathway
exists; and (3) it has not' been concluded whether a current or future exposure
pathway exists. If current or future exposure pathways do not exist, then the
demonstration of no substantial hazard to human health or the environment is
essentially complete. If current or future exposure pathways do exist, then
the concentration estimates obtained from the environmental fate and transport
modeling described in this section will be used for characterizing risk
(Chapters 6 and 7). If it has not been concluded whether a current or future
exposure pathway exists, then the environmental fate and transport modeling
described by this section will assist in that determination.
Estimating ambient concentrations at an exposure point is essentially a
two-step process. The first step, quantifying the amounts of chemicals that.
will be released to the environment, was completed as described in Chapter 2.
Given these release quantities, the second step is to predict the
environmental transport and fate of each indicator chemical in the identified
medium of the exposure pathway. An example is the movement of a contaminant
released to ground water from contaminated soil and then transported to a
drinking water well. For situations where prior releases have occurred,
available ground-water monitoring data can be used to support estimates on the
extent and duration of exposure. Concentrations associated with these prior
released chemicals would be considered background concentrations.
Concentrations for each indicator and background chemical must be
estimated at each of the complete exposure point locations identified in
Worksheets 5-1 and 5-2. Concentrations of substances need to be estimated as
a function of time (i.e., short-term and long-term) in each environmental
medium (i.e., surface water, ground water, soil, or air) through which
potential exposures could occur. For example, if in completing Worksheet 5-1,
it is determined that potential exposure routes for a nearby residential area
are ingestion of contaminated ground water and inhalation of contaminated air,
chemical concentrations over time must be predicted for both ground water and
air at this location.
Numerous analytical techniques are available to perform the calculations
required in these two steps. The techniques are described in detail elsewhere
(see footnote 2). The techniques vary in sophistication from simple, desk-top
tj Note that the list of indicator chemicals includes the background
chemicals evaluated in Chapter 4.
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OSWER Directive 9483.00-2
5-16
methods that provide rapid, order-of-magnitude projections, to more rigorous
approaches involving computer modeling that may give more accurate results,
but require more time and resources to undertake. All techniques require
certain chemical- and site-specific data, although the data requirements vary
with the degree of sophistication of the method used. The appropriate level
of sophistication will be influenced by data availability, and by the demands
and bounds of the evaluation for a specific site. Modeling, especially of
long-term subsurface transport, has significant uncertainty associated with it
that must be considered. Ground-water models have not been validated over the
long time periods of concern, and many subsurface environments (e.g.,
anisotropic, heterogeneous) are not suited to available-models. Sophisticated
computer models are expensive to use, often require extensive data inputs, and
still may have limited accuracy because of gaps in the input data. Thus,
simple environmental fate models using conservative (i.e., reasonable worst
case) assumptions are usually most appropriate for use in risk-based variance
applications. If more complex models are used, reasonable worst case
assumptions are usually still needed due to the uncertainties involved. In
any case, the applicant must thoroughly document the models used and include
validation references and documentation of previous applications.
Ideally, the concentrations derived from modeling will be in the form of
exposure profiles similar to the release profiles discussed in Chapter 2. Due
to dispersion, degradation, and other factors, the exposure profile at any
given exposure point will be attenuated compared to the release profile. That
is, the peak concentration will not be as high as the concentration associated
with the release volumes, and the length of time that the chemical .will be
present at the exposure point will be longer than the release duration.
Exhibit 5-5 depicts an idealized curve of concentration versus time and, as
shown, the concentration will generally increase over time to some maximum
level and then decrease (assuming the release ends) to a background level.
This background level may actually remain higher than the previous background
level due to chemical- and media-specific properties (e.g., adsorption).
Short-term concentrations (STC) are averaged over a relatively short time
period (10 to 90 days) and are used to evaluate potential subchronic effects
of exposure for the human health effects evaluation and acute effects for the
environmental impact evaluation. Long-term concentrations (LTC) are averaged
over longer time periods, up to an average human lifetime (70 years) for the
health effects evaluation and less for the environmental impact evaluation.
LTCs are used to assess both the carcinogenic and chronic noncarcinogenic
effects of exposure. For human exposure and environmental receptor exposure,
the LTC will always be less than or equal to the STC.
Exhibit 5-5 illustrates the difference between STC and LTC. The STC may
be viewed as the highest average concentration occurring during any group of
consecutive days (generally 10 to 90). In Exhibit 5-5, the STC is essentially
the peak concentration (since 10 to 90 days is a short time compared to the
time frame of this particular curve). The LTC is somewhat more difficult to
derive than the STC. In addition, different LTCs are often used to assess
carcinogenic and chronic noncarcinogenic health risks. One method for
assessment of carcinogenic human health risk is to estimate the area under the
curve of exposure point concentration versus time, either graphically or
mathematically, and divide by 70 years. This procedure is illustrated by the
large shaded box in Exhibit 5-5. For assessment of chronic noncarcinogenic
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OSWER Directive 9483.00-:
Exhibit 5-5
ILLUSTRATION OF SHORT-TERM AND.
LONG-TERM CONCENTRATIONS*
Release
Short-Term
Concentration
(STC)
Exposure
Point
Concentration
Long-Term
Concentration
(LTC)
Background
Short-Term Average
Concentration vs. Time
Actual Concentration
vs. Time
Long-Term Average
Concentration vs. Time
90 Days
70 Years
Time
"Not to Scale
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OSWER Directive 9483.00-2
5-18
health risks, the LTC should sometimes be an average over a shorter time
period than 70 years (thereby avoiding the artificial reduction of the LTC
value resulting from averaging over a full lifetime). The averaging time for
assessing long-term noncarcinogenic human health risk should correspond to
that used in the to.xicologic study from which the toxicity values (i.e.,
reference doses) were derived. Unless otherwise known, 10 years should be
used for human exposure (corresponding to the 90-day subchronic studies from
which many of the chronic toxicity values are derived). Therefore, the LTC to
use for assessing chronic noncarcinogenic human health risk would be the
highest 10-year average concentration. If significant noncarcinogenic human
health risk is projected using this approach, it may be .-necessary to refer to
the specific toxicologic studies on which the toxicity values are based to
determine the most appropriate averaging period.
The following example illustrates the above points. The concentration
from a catastrophic release might be high for a few months and then decrease
substantially. The human STC would be obtained by averaging concentrations
over the 10- to 90-day period of greatest exposure, the LTC for assessing
human cancer risk would be the average over the 70-year period that results in
the highest concentration, and the LTC for assessing human noncancer risk
would be the average over the 10 year period that results in the highest
concentration.
There are three recommended approaches for addressing the unavoidable
estimation uncertainties likely to be encountered in the exposure assessment.
One is to use a conservative (i.e., reasonable worst-case) approach in- making
the assumptions necessary for a particular estimation method. The consequence
of making conservative assumptions is that risks may be substantially
overstated but are unlikely to be understated in the final analysis. All
assumptions and the basis for each should be recorded. This simple
conservative approach is probably sufficient for the environmental impact
evaluation, but is usually insufficient for the health effects evaluation
because of the need to characterize uncertainty using a range of estimates.
A second and generally better approach is to calculate lower,
representative, and upper estimates for all exposure point chemical
concentrations. Ranges of constituent concentrations in the tank systems and
ranges of hydrogeologic parameters are values that may be used to calculate
lower, representative and upper exposure point concentrations. If this
approach is followed and all three sets of concentration estimates are carried
through the entire hazard evaluation (ultimately resulting in three sets of
risk estimates), the results will provide not only an estimate of the risk
magnitude but also a good indication of the overall uncertainty of the
analysis. Of course, this approach requires more calculation effort, but it
is a straightforward way to account for analytical and data uncertainties.
This approach, which yields a lower, representative, and upper estimate of
each risk projection, emphasizes the uncertainty involved by displaying it
quantitatively. A large disparity between the estimates would indicate
relatively high uncertainty, and vice-versa. This approach requires that
three sets of worksheets be completed, one for the lower estimate, one for the
representative estimate, and one for the upper estimate. The worksheets in
this document are based on this approach.
A third possible approach, preferred, but generally beyond the scope of
the risk-based variance process, is to model the important variables
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OSWER Directive 9483.00-2
5-19
determining chemical concentration and risk stochastically. This approach is
similar to the second in that a range of estimates is obtained. This
stochastic approach differs from the first two deterministic approaches by
allowing estimation of a risk distribution from which median and 90th (or
other) percentile values can be determined. But this stochastic approach is
more complex and time-consuming than a deterministic approach, and it still
only accounts for uncertainty due to the variables modeled stochastically. It
does not address other sources of uncertainty such as applicability of the
release or transport models to the real site situation (i.e., model
uncertainty).
To account for the behavior of all released chemicals, it is necessary to
consider systematically the extent of chemical fate and transport in each
environmental medium. In this way, one can consider the predominant
mechanisms of chemical transport and transformation, and disregard less
significant mechanisms. In the following sections, brief descriptions of the
mechanisms for each of the major environmental release media are presented.
Worksheets 5-3 and 5-4 are provided as formats for recording the estimated
chemical concentrations for each exposure point.
5.2.1 Surface Water Transport Modeling
The environmental fate of hazardous materials entering surface water
bodies is highly dependent on the type of water body and the specific
chemicals involved. Relatively simple, straightforward approaches are
available for estimating environmental concentrations in rivers and streams.
Mora complex methods, however, may be necessary for predicting concentrations
resulting from releases to lakes, reservoirs, and estuaries. Applicable
methods are described elsewhere (see footnote 2). In addition, states
oftenhave approved models for use in issuing the National Pollutant Discharge
Elimination System (N'PDES) Permits as required by the Clean Water Act.
At some sites, relatively precise estimates of chemical fate and transport
in surface water may be required. Sophisticated computer models are available
for predicting the behavior of chemicals released to water. The models have
varying capabilities, data requirements, computer resource requirements, and
sophistication of output. The reasons for selecting a particular model should
be well documented. Generally, for risk assessments in the risk-based
variance application, the simplest model that reasonably represents the system
should be used.
5.2.2 Ground-Water Transport Modeling
In describing the behavior of contaminants released to ground water from a
hazardous waste tank system, two major subsurface zones must be considered:
the unsaturated soil zone above the ground water (vadose zone), and the
saturated zone, commonly called the aquifer. In general, after a substance is
released, it first moves vertically down through the unsaturated soil zone to
the ground water. Then, after initial mixing in the ground water, the
substance travels horizontally because of the advective flow of the ground
water underlying the site. The main processes that affect the fate and
transport of contaminants in these two zones are advection (including
infiltration and leaching from the surface), dispersion, sorption (including
-------
WORKSHEET 5-3
CON IAM I NAN I CUNCENIRATIONS AI HUMAN EXPOSURE POINTS
INSIRUCIIONS:
1. List all human indicator chemicals (use additional
worksheets if necessary).
2. List all release media Tor each chemical: ij round water,
surface water, soil, and air.
3. List all exposure points Tor each release mod mm.
<4. List projected short-term and long-term cuiK.ontra t ions
(lower, tipper, and representative) Tor each e>post
-------
WORKSHEET 5-H
CON IAMI NAN I CONCI MIRATIONS AT ENVIRONHENIAL RECEPTOR EXPOSURE POINIS
INS!RUCTIONS;
1. list all environmental indicator chemicals (use additional
worksheets if necessary).
2. List all release media Tor each chemical.
3. List all environmental receptor exposure points for each release medium.
<4. List projected short-term and long-term concentrations for each
exposure point. Be sure to include backijiouiid concentrations
Prom Worksheet 'i-2. Note that water concent rat ions are in mg/l
and air concentratons are in mg/m3. Attach all calculations
documenting the concentration estimates to this worksheet.
facility il>:
Cluster/Tank System:
On m:
Analyst:
Qua Ii ty Control:
Chemical
Release
Modi urn
1. Benzene
Exposure
Point
Concentration
Units
Short-Term
Concentrat ion
Iong-Term
Concentration
Spring
mg/l
0.01
0^008
2. Lead
Ground Water
Spring
mg/l
0.005
0.001
3. Zinc
Ground Water
Spring
mq/l
0.001
0.0003
H.
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OSVER Directive 9483.00-2
5-22
reversible adsorption, ion exchange, coraplexation, and precipitation), and
degradation. As a released substance flows away from the source area, these
processes generally act to reduce its concentration.
Time plays a key role in the movement of contaminants in the subsurface
environment. Unlike the air (see below) and surface water media where
releases of chemicals generally result in downwind or downstream ambient'
concentrations within relatively short times after release (i.e., minutes,
hours, or days), ground water moves slowly and takes much longer (years) to
transport contaminants. Consequently, the estimation of ground-water
concentrations at a given exposure point must be bounded by a specified time
frame for which the hazard evaluation will be conducted. Therefore, for
purposes of evaluating long-term individual human health risks, ground-water
concentrations estimated for the long-term time period with the highest
average concentration should be used. To represent short-term concentrations,
use the peak concentration value.
Numerous mathematical models are available that describe pollutant fate
and transport in the subsurface environment. These models are described
elsewhere (see footnote 2). These models attempt to define waste migration
over time and distance using the physical and chemical processes involved.
The physical and chemical characteristics considered by these models include
the following:
boundary conditions (hydraulic head distributions,
recharge and discharge points, locations and types of
boundaries);
material properties (hydraulic conductivity, porosity,
transmissivity, extent of hydrogeologic units);
attenuation mechanisms (adsorption-desorption, ion
exchange, complexing, nuclear decay, ion filtration, gas
generation, precipitation-dissolution, biodegradation,
chemical degradation);
molecular diffusion and hydrodynamic dispersion
(transverse, longitudinal, vertical, and multi-phase);
and
waste constituent concentrations (initial and
background concentrations, boundary conditions).
These characteristics are incorporated into models by combining two sets of
transport expressions: a ground-water flow equation and a chemical mass
transport equation. The result is a prediction of solute transport in the
ground-water system, with chemical reactions considered.
Separate models exist for predicting transport through both the
unsaturated and saturated zones. Models are often linked into a comprehensive
package to effectively simulate movement through both unsaturated and
saturated soil zones. In addition, some ground-water models have the
capability of predicting hazardous substance fate throughout both zones. Most
of these models are designed to be used with a computer.
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OSWER Directive 9483.00-2
5-23
Models for ground-water transport generally have not been fully verified,
and their reliability is difficult to assess. Site-specific conditions and
the analyst's ability to account for site-specific characteristics with
quantitative input data influence the reliability of model results. Carefully
applied professional judgment is therefore necessary both in using the models
and in interpreting the results. Important sources of uncertainty should be
noted and their impact on model results should be anticipated and recorded.
5.2.3 Air Transport Modeling
The predominant mechanisms that affect the atmospheric fate and transport
of substances released to the air are advection, dispersion and, in some
cases, natural decay. Ambient concentrations of a chemical at a specified
downwind distance from the site or in the ambient indoor air can be determined
as a direct function of chemical release rate when these key processes are
considered. See footnote 2 for guidance on appropriate modeling techniques .
Sophisticated computer models are also available for the analysis of
environmental fate of hazardous substances in air. As with the models for
other media, these models vary in complexity, input data requirements,
computer resource requirements, and model capabilities. Again, simple models
are generally preferable. If a computer modeling approach is desired for a
particular situation, select the modeling procedure most appropriate to the
circumstances under study. Again, document the rationale for selecting a
particular model.
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OSWER Directive 9483.00-2
CHAPTER 6
HEALTH EFFECTS EVALUATION
The health effects evaluation is a major part of the demonstration for a
risk-based variance from the secondary containment requirements of the
hazardous waste tank system regulations. This chapter presents a method for
compiling the information described in Chapters 2 through 5 for the purpose of
evaluating the present and potential hazard to human health in the event of a
release of hazardous waste from specific tank systems or components. The
evaluation has two main components: (1) a comparison of estimated human
exposure point concentrations (from Chapter 5) to health-reiated quality
standards; and (2) a quantitative estimate of potential noncarcinogenic and
carcinogenic risk. The first component of the health effects evaluation,
comparison of exposure point concentrations to quality standards, is addressed
in Section 6.1. In certain situations this comparison to standards will
suffice for the health effects evaluation. The second component, quantitative
estimates of risk, is addressed in Sections 6.2, 6.3, and 6.4. Section 6.2
provides a format for estimating chemical intake by humans at the exposure
points, Section 6.3 guides the applicant in obtaining toxicity values of the
chemicals, and Section 6.4 demonstrates the procedures for combining intakes
with toxicity values to obtain estimates of human health risk. See Exhibit
6-1 for a flowchart of this process.
6.1 COMPARE EXPOSURE POINT CONCENTRATIONS TO'ESTABLISHED
QUALITY STANDARDS
At this point in the process, the projected concentrations of indicator
chemicals at exposure points1-1 are compared to established quality
standards.2-1 If the ratio of a projected concentration to an established
quality standard for a particular chemical at an exposure point is greater
than one, then adverse health effects may be anticipated. To consider
possible cumulative effects, the ratios of projected concentration to
established quality standard for each chemical are summed for each exposure
media (i.e., water or air) at each exposure point. If this sum is greater
than one, and if the standard is entirely health-based and chemicals involved
produce the same adverse effect by similar modes of action, then adverse
effects may be anticipated. Further guidance on the interpretation and
calculation of the summation of ratios may be obtained from the Guidelines for
the Health Risk Assessment of Chemical Mixtures (51 Federal Register 34014,
September 24, 1986).
There are basically two types of quality standards: (1) those that are
strictly health-based; and (2) those that, in addition to being health-based,
also consider risk-benefit balancing or technological feasibility. If any
standards exist for an indicator chemical, then the standards(s) must be
1J Note that the list of indicator chemicals includes the background
chemicals evaluated in Chapter 4.
2J For the purpose of this discussion, "standard" refers to any
health-based standard, criterion, goal, or advisory.
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OSWER Directive 9483.OC
Exhibit 6-1
OVERVIEW OF HEALTH EFFECTS EVALUATION
SECTION 6.1
Compare estimated exposure point concentrations (from Chapter 5)
to established quality standards (from Appendix C).
Health effects
evaluation complete.
Do
acceptable
standards exist
for all indicator
chemicals ?
No
' SECTION 6.2
Calculate intakes from air, water,
food, and dermal absorption.
SECTION 6.3
Identify Toxicity Values (from Appendix C):
Acceptable Imake-Subchromc (AIS);
Acceptable Intake-Chronic (AIC); and
Carcinogen Potency Factor (CPF).
SECTION 6.4
Characterize risk:
For non-carcinogens, compare estimated intakes (from Section 6.2)
with AlSs and AlCs (from Section 6.3).
For carcinogens, combine estimated intakes (from Section 6.2)
and CPF (from Section 6.3).
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OSWER Directive 9483.00-2
6-3
compared to the estimated exposure point concentrations. The standards that
are most pertinent to site exposure conditions will be judged for accept-
ability. That is, the organism (tested or studied), the temporal aspect, any
economic and/or technological considerations, and the environmental media and
its use must all be reasonably identical to those of the exposure point. For
example, standards that were established under statutory authority requiring
risk-benefit balancing or technology-based considerations may not always be
acceptable.3J
This section describes the procedure for comparing exposure point
concentrations to standards. Although the applicant should be aware that EPA
continues to update toxicological information and, based on these updated
data, may issue revised standards, the focus is on numerical criteria that are
in the form of ambient environmental concentration levels. Standards
expressed in intake or dose units are considered in the sections concerning
quantitative estimates of risk (Sections 6.2, 6.3, and 6.4).
The comparison of exposure point concentrations to acceptable established
standards for all indicator chemicals will usually suffice for a human health
effects evaluation. Consequently, if all indicator chemicals in a tank system
have acceptable standards, then the remainder of the risk assessment described
in this chapter is not necessary. At sites where some indicator chemicals do
not have acceptable standards, make the comparison for those chemicals that do
have standards and then proceed with the complete risk characterization
process for all indicator chemicals. Therefore, in cases where acceptable
standards are not available for all indicator chemicals, the health effects
evaluation will include both .a comparison to standards and the risk assessment
process described in the remainder of this chapter.
At the present time, EPA considers the established standards to be Safe
Drinking Water Act maximum contaminant levels (MCLs), MCL goals (MCLGs),
federally-approved state water quality standards"-1 developed under the Clean
Water Act, other state standards, federal ambient water quality criteria
(WQC), and national ambient air quality standards (NAAQSs). -Federal drinking
water health advisories (DWKAs) are nonregulatory (i.e., nonenforceable)
standards, although they are useful for comparison purposes in lieu of other
standards. Appendix C lists all of the above standards and criteria for
ambient environmental concentrations of contaminants.
IJ 51 Federal Register 25453, July 14, 1986.
UJ States known to have specific numerical ambient water quality
standards for toxic chemicals include Alabama, Alaska, Arizona, Arkansas,
Delaware, Florida, Illinois, Indiana, Iowa, Kentucky, Louisiana, Minnesota,
Mississippi, Montana, Nebraska, New Jersey, New Mexico, North Dakota, Ohio,
Oregon, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia,
West Virginia, and Wisconsin. Appropriate state agencies for these and other
states should be consulted to determine if such standards are in effect at the
time of the site evaluation.
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' OSVER Directive 9483.00-2
6-4
The determination of exactly which standards are acceptable to a
particular site should be made on a site-specific basis. Not all standards
will be acceptable for every site. For potential ground-water and surface
water exposure via public drinking water, the most acceptable comparison
values may be MCLs. For other surface water, when aquatic organism ingestion
is an exposure pathway, unadjusted ambient water quality criteria may be most
acceptable. For other potential ground-water exposures, acceptable comparison
values may be adjusted (for drinking water only) ambient water quality
criteria. For air exposure,5-1 NAAQSs are acceptable. Other standards may
be used for comparison as well, provided they correspond to the environmental
medium for which they were designed and are appropriate to site conditions.
Criteria inappropriate for a health effects evaluation of long-term chemical
exposures include LD-n values (the dose of a chemical that-results in SO
percent fatality in a population) and unadjusted occupational threshold limit
values (TLVs; average concentrations of chemicals in air that should not be
exceeded during an eight hour per day, 40 hour work week). Standards should
correspond to the medium (i.e., water or air) for which they were developed
and must be relevant to site conditions. If standards are available for all
indicator chemicals, but are not acceptable given the site exposure
conditions, a full risk characterization must be completed.
Some ambient concentration standards will be pertinent to specific site
conditions, while others can be adjusted to make them useful. For example, if
a standard applies to a different environmental medium or exposure route than
one of concern at a site, it would usually not be appropriate to use the
standard without adjustment. As an illustration of this situation, water
quality criteria, which were developed for surface water, will need to be
adjusted for application to ground water by deletion of the fish ingestion
exposure component (as in Exhibit C-10). Concentration requirements and
criteria may also be based on a different level, frequency, or duration of
exposure than those found at a specific site.
For some chemicals, several different standards .may be acceptable as
comparison values. In this case, note the most appropriate comparison value.
Appropriateness is determined in part by how pertinent the criterion is to
exposure conditions at the site (e.g., exposed population characteristics,
duration and timing of exposure, exposure pathways) and in part by how
recently the value was developed. Some standards have been developed recently
and may reflect new information compared to older values. Some standards may
have been scrutinized more closely than others and may consequently have more
scientific credibility. Other standards may be current and scientifically
accepted but not pertinent to exposure routes at the site and, therefore,
unsuitable. Consequently, the most appropriate comparison value is the most
current, credible, and pertinent value available.
Use Worksheet 6-1 to compare established quality standards to
environmental concentrations projected for human exposure points (from
Worksheets 5-1 and 5-3). Calculate ratios between predicted concentrations
SJ Secondary containment may appreciably decrease air exposure risk from
tank systems containing highly volatile compounds.
-------
WORKSHEET 6-1
COMPARISON Of HUMAN IXI'OSUHE POINT CONCENIKATIONS TO ESTABLISHED STANDARDS
INSTRUCT IONS;
1. Indicate exposure point and list all indicator chemicals (use additional
worksheets if necessary).
2. Record each chemical's concentration range anil ieprcsentative value
(from Worksheet 3-3).
3. Refer to Exhibits C-8 to C-12 and any existing state water quality standards
to obtain the established standards. Recoid the value of the standard (include:
facility 10:
Cluster/Tank System:
O.i to:
Analyst:
Qua Ii ty Control:
the risk, if known, in parentheses), its source (i.e.. Maximum Contaminant Level (MCI), Clean Water Act State Standard
(CWASS), Other State Standard (OSS). National Ambient Air Quality Standard (NAAQS). MCI Goal (MCIG), Water Quality Criteria
(WQC), or Drinking Water Health Advisory (OWIIA)), and any other pertinent information (e.g.. whether a Owl IA value refers to a
one-day or ten-day exposure). Indicate llio most appropriate standard with an asterisk.
i|. Calculate the ratios of concentrations to standards.
5. Sum the ratios within a standard (e.g., add all the MCI ratios), and sum the most appropriate ratios (no more than one Tor
each chemical). Summed ratios greater than out; should not be intrepreted too strongly unless further analysis has segregated
the chemicals and their standards by critical oiled.
Exposure Point: facility boundary, west.
Concentration (circle one): Short-term
Long-term
ChemicaI
Projected Exposure
Point. Concentration {!OU/..Ll
Cstab 11 shed
ua jj tv Standards_
Ratio of Exposure Point
Concentration to Standard
1. Cadmium
2. Ethyl benzene
3.
Lower Upper Rep res. Value (mg/l) Source
0.001 0.1 0,08 0.01 MCL"
0.01 WQC
0,018 OWIIA
0,5 2.0 1.0 - MCL
2.H WQC"
3 . '( OWIIA
Totals: MCL
WQC
OWIIA
Host appropriate:
Lower
0.1
0,1
0.06
0.21
0.15
0, 1
0,31
0.21
0.31
Upper Repres.
10 ' 8
10 8
" "
tf.83 0,'|2
0,59 0,29
10 8
10.83 8.i|2
6.19 i|.69
"Most appropriate standard.
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OSWER Directive 9483.00-2
6-6
and standards, and designate whether concentrations exceed or fall below the
standards. Indicate the most appropriate standard based on the criteria
discussed previously in this section. When risk levels associated with these
standards are known, they should also be recorded. Although individual ratios
may be less than one (indicating adverse health effects due to that chemical
are unlikely), summing the ratios may result in a value greater than "one
(indicating possible health effects). Therefore, sum the ratios for each
chemical within a standard (e.g., add all the MCL ratios) to obtain an
indication of cumulative effects. Also, sum the most appropriate ratios (one
for each chemical) from the worksheet. The assumption of additivity reflected
in the ratio summation procedure is applied most properly to chemicals that
produce the same effect by the same mechanism. Therefore, summed ratios
greater than one should not be interpreted too strongly uniess further
analysis has segregated the chemicals and their standards by critical effect.
Factors used in the development of the required standards listed in
Appendix C are discussed briefly in the following subsections.
6.1.1 National Primary Drinking Water Standards/Maximum
Contaminant Levels (MCLs)
Drinking water standards developed under the Safe Drinking Water Act are
promulgated as maximum contaminant levels (MCLs). MCLs are currently
available for 16 specific chemicals (10 inorganics and 6 organic pesticides),
total trihalomethanes (covers four chemicals), certain radionuclides, and
microorganisms. An MCL for a toxic'chemical represents the allowable lifetime
exposure to the contaminant for an adult weighing 70 kilograms who is assumed
to ingest two liters of water per day. Total environmental exposure of a
particular contaminant from various sources was considered by EPA in
calculating specific MCLs. The amount of the substance to which the average
person is likely to be exposed from all sources (e.g., air, food, water) was
estimated, and then 'the fraction of the total intake resulting from drinking
water ingestion was determined. Lifetime exposure limits were set at the
lowest practical level to minimize the amount of contamination ingested from
water, especially when exposure from other sources is large. The MCL
calculation is adjusted by an exposure factor to reflect bodily absorption
associated with water consumption.
In addition to health factors, an MCL is required by law to reflect the
technological and economic feasibility of removing the contaminant from the
water supply. The limit set must be feasible given the best available
technology and treatment techniques. A safety factor is included in each of
the standards to provide adequate protection for sensitive populations that
may be at special risk, such as infants and children. Safety factors vary ,
from chemical to chemical because of the different health effects associated
with each.
Note that EPA recently proposed MCLs, which will be established standards
when promulgated, for eight volatile organic chemicals (50 Federal Register
46902-46933, November 13, 1985). They are currently in the form of MCL goals
(MCLGs) (See Section 6.1.2)'-. Under the Safe Drinking Water Act Amendments of
1986 (P.L. 99-339), EPA is required to promulgate MCLs for 83 contaminants
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OSWER Directive 9483.00-2
6-7
within three years. When promulgated, these MCLs will also become established
standards. Exhibit C-8 lists the MCLs promulgated as of publication of this
document.
6.1.2 MCL Goals (MCLGs)
EPA is now in che process of developing maximum contaminant level goals
(MCLGs),Sj which are entirely health-based, to serve as guidance for
establishing drinking water MCLs. EPA recently promulgated MCLGs for eight
volatile organic chemicals (40 CFR 141.50 (50 Federal Register 46880-46901,
November 13, 1985)) and proposed MCLGs for a larger group of synthetic organic
chemicals, inorganic chemicals, and microorganisms (50 Federal Register
46936-47022, November 13, 1985). When these proposed MCLGs are promulgated,
they will automatically become established standards. Exhibit C-9 lists the
MCLGs promulgated as of publication of this document.
6.1.3 Federally-Approved State Water Quality Standards
Federally-approved state water quality standards developed under the Clean
Water Act are established standards in that state. At a minimum, states
listed in footnote 4 have promulgated at least some federally-approved water
quality standards for specific toxic chemicals. The tank owner/operator is
responsible for determining the availability of appropriate state water
quality standards for the water resources surrounding a facility.
State water quality standards under the Clean Water Act serve the dual
purposes of establishing the water quality goals for a specific water body and
the regulatory basis for water quality-based controls beyond the
technology-based levels of treatment required by Sections 301(b) and 306 of
the Clean Water Act. Water quality standards are adopted by states (or, where
necessary, promulgated by EPA) to prote-ct public health and welfare, enhance
the qualicy of the water, and serve the purposes of the Act. A water quality
standard consists of basically two parts: (1) a "designated use" (or uses),
based on the water body's use and value for public water supplies, propagation
of fish, shellfish, wildlife, recreation, navigation, agriculture, industry,
and other purposes; and (2) "criteria," which are numerical limits or
narrative statements necessary to protect the designated use.
States must adopt appropriate water quality criteria sufficiently
stringent to protect the designated uses. Numerical criteria may be based on
ambient water quality criteria recommendations published by EPA (see Section
6.1.4) or developed by other scientifically defensible methods. States may
also modify EPA's recommended criteria to reflect local environmental
conditions and human exposure patterns before incorporation into water quality
standards. When a criterion for the protection of human health must be
developed for a chemical for which a national criterion has not been
recommended, the state should consult EPA headquarters for assistance.7-1
*J MCLGs were previously known as recommended MCLs (RMCLs).
7J Guidelines for deriving human health-based water quality criteria are
published in 45 Federal Register 79318-79379, November 28, 1980.
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OSWER Directive 9483.00-2
6-8
6.1.4 Federal Ambient Water Quality Criteria (WQC)
Federal ambient water quality criteria (WQC) for the protection of human
health have been developed for 62 out of 65 classes of toxic pollutants (a
total of 95 individual chemicals have numerical health criteria). The health
criterion is an estimate of the ambient' surface water concentration that will
not result in adverse health effects in humans. In the case of suspect or
proven carcinogens, concentrations associated with an incremental cancer risk
of 10 are provided to supplement a criterion of zero. The federal
criteria are non-enforceable guidelines, which many states have used in the
development of enforceable ambient water quality standards (see Section 6.1.3).
For most chemicals, federal WQC to protect human health have been
published for two different exposure pathways. One criterion is based on'
lifetime ingestion of both drinking water and aquatic organisms, and the other
is based on lifetime ingestion of aquatic organisms alone. The calculations
incorporate the assumption that a-70-kilogram adult consumes 2 liters of water
and/or 6.5 grams of aquatic organisms daily for a 70-year lifetime. Because
the criteria based on lifetime ingestion of aquatic organisms alone are not
relevant to most exposure situations, calculations have been made to derive an
adjusted criterion for drinking water ingestion only, based on the two
published criteria and the same intake assumptions. Exhibit C-10, therefore,
presents the following: 1) the criteria based on lifetime ingestion of both
drinking water and aquatic organisms; and 2) the adjusted criteria for
drinking water only. The adjusted criteria are more appropriate than the
non-adjusted for sites with potential contamination of ground-water sources of
drinking water because they are based on more realistic exposure assumptions
(i.e., exclusion of aquatic organism ingestion as an exposure pathway). WQC
have been derived for both noncarcinogens and carcinogens. The following
paragraphs briefly describe the methods used by EPA to derive WQC.
Derivation of Criteria for Noncarcinogens. On the basis of a survey of
the toxicology literature, EPA established a "no observed adverse effect
level" (NOAEL) for each chemical. The NOAELs are usually based on animal
studies, although human data are used whenever available. By applying a
safety factor to account for the uncertainty in using available data to
estimate human effects, an acceptable daily intake (ADI) is determined.
Criteria (i.e., water concentrations) are then derived from the ADIs and the
standard intake assumptions given above.
Derivation of Criteria for Carcinogens. The same exposure and intake
assumptions used for noncarcinogens are used for potential carcinogens. A
literature search for human and animal carcinogenic effects form the basis for
EPA's estimate of the risk posed by potential "human carcinogens. Because
methods are not currently available to establish the presence of a threshold
for carcinogenic effects, the criteria for all carcinogens state that the
recommended concentration for maximum protection of human health is zero. EPA
also estimated water concentrations corresponding to incremental risk levels,
using a linear, non-threshold extrapolation model. Extrapolation models
provide only an estimate of risk, but represent the best available tool for
describing the potential threat of a substance, given certain assumptions. In
its published criteria, EPA provides water concentrations corresponding to
incremental lifetime cancer risks of 10 ,10 , and 10
-------
OSWER Directive 9483.00-2
6-9
6.1.5 National Ambient Air Quality Standards (NAAQSs)
NAAQSs are available for six chemicals or chemical groups and for airborne
particulates; of these, the NAAQSs for lead, hydrocarbons, and airborne
particulates appear to be the most useful for the health effects evaluation.
In the development of NAAQSs, sources of the contaminant that contribute to
air pollution and all sources of exposure to the contaminant (e.g, food,
water, air) are considered in determining the health risk. N'AAQSs are based
exclusively on air quality criteria (e.g., health effects, visibility) for
each air pollutant and not the costs (economics) of achieving the standards or
the technological feasibility of implementing the standards. Standards can be
promulgated as annual maximums, annual geometric means, annual arithmetic
means, or other time periods which vary from one hour to one year depending on
the pollutant.
The standards must allow for an adequate margin of safety to account for
unidentified hazards and effects. There is no rule used in setting the margin
of safety for the standards. The law requires EPA to direct its efforts at
groups of particularly sensitive citizens, such as bronchial asthmatics and
emphysematics. In developing NAAQSs, EPA must specify the nature and severity
of the health effects of each contaminant, characterize the sensitive
population involved, determine probable adverse health effect levels in sensi-
tive persons, and estimate the level below which an adequate margin of safety
reduces or eliminates risks. NAAQSs are based primarily on the direct health
effects of chemicals to sensitive groups based on scientific data. Exhibit
C-12 lists the existing NAAQSs.
6.1.6 Drinking Water Health Advisories (DWHAs)
In addition to MCLs and MCLGs, EPA also provides drinking water suppliers
with guidance on chemicals that may be encountered in a water system, but for
which no federal standard exists. The Office of Drinking Water's nonregu-
latory (i.e., nonenforceable) DWHAs are concentrations of contaminants in
drinking water at which adverse effects would not be anticipated to occur.
Therefore, they are useful as an indication of potential hazard. A margin of
safety is included to protect sensitive members of the population. The DWHA
numbers are developed from data describing noncarcinogenic end-points of
toxicity (e.g., neurological effects, kidney damage). They do not incorporate
quantitatively any potential carcinogenic risk from such exposure. The Office
of Drinking Water has recently developed DWHAs for 54 chemicals or chemicals
groups, and these values are summarized in Exhibit C-ll.
Under certain circumstances and when the appropriate toxicological data
are available, DWHAs may be developed for one-day, ten-day, longer-term
(several months to several years), and lifetime durations of exposure.
One-day and ten-day DWHAs are calculated for a 10 kg child (a one-year old
infant) assumed to drink one liter of water per day. Lifetime DWHAs are
calculated for a 70 kg adult, assumed to drink two liters of water per day.
Longer-term DWHAs are calculated for both a 10 kg child and a, 70 kg adult.
For chemicals that are known or probable human carcinogens according to the
proposed Agency classification scheme, non-zero one-day, ten-day, and
longer-term DWHAs may be derived, with attendant caveats. DWHAs for lifetime
exposures are not recommended for this group of substances. For these
-------
OSWER Directive 9483.00-2
6-10
potential carcinogens, drinking water concentrations associated with a
projected excess lifetime cancer risk of 10 are provided. Comparison of
these values to measured or predicted drinking water concentrations provide an
indication of the magnitude of potential carcinogenic risk.
6.2 ESTIMATE CHEMICAL INTAKES
If acceptable, established quality standards exist for all indicator
chemicals, then the health effects evaluation is complete and, therefore,
there is no need to proceed with Sections 6.2, 6.3, and "6.4. If acceptable
standards do not exist for all indicator chemicals then proceed with Sections
6.2, 6.3 and 6.4. In this section (Section 6.2), methods are presented for
estimating human exposures using the environmental concentrations of
substances that were estimated by the methods described in Chapter 5.
Human exposure is expressed in terms of intake, which is the amount of
substance taken into the body per unit body weight per unit time.IJ Intakes
are calculated separately for exposures to chemical contaminants in each
environmental medium (air, ground water, surface water, and soil). Then, for
each potntially exposed population, intakes for the same route of exposure are
summed, resulting in a total oral exposure and total inhalation exposure.
Dermal exposure, if determined to be important, should be estimated separately.
Because short-term (subchronic) exposures to relatively high concentra-
tions of chemical contaminants can cause different toxic effects than those
caused by long-term (chronic) exposures to lower concentrations, two intake
levels are calculated for each chemical: (1) the subchronic daily intake
(SDI); (2) and the chronic daily intake (GDI). These calculated intakes are
based on short-terra and long-term concentrations derived for each indicator
chemical and any identified chemicals from other sources (i.e., background)
using the procedures in the preceding chapter. All intakes are expressed in
mg/kg/day.
The following subsections give standard methods to estimate human intakes
through air, ground water, and surface water. If other exposure routes, such
as dermal absorption and soil ingestion are important, contact the Exposure
Assessment Group, Office of Research and Development, U.S. EPA, Washington,
D.C. 20460, for additional guidance. Standard intake assumptions are given
in Exhibit 6-2. If more accurate site-specific information is available, it
can be used to give a better representation of risk at the site. See Exhibit
6-2 for an example of how to use the standard assumptions and how to make
*J The term "intake" (i.e., the amount of substance taken into the
body) is used instead of dose (i.e., the amount of substance absorbed by the
body) because the information required to estimate dose is often unavailable.
To estimate dose, information indicating the amount of a chemical that may be
absorbed (e.g., across lung or gastrointestinal tract lining or through the
skin) and subsequently distributed to target organs or tissues would be
needed. When absorption data are available they can be incorporated into the
assessment. Because adequate absorption data for specific chemicals are
relatively rare, they cannot be used consistently and are not included here.
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OSWER Directive 9483.00-2
6-11
EXHIBIT 6-2
STANDARD VALUES USED IN DAILY INTAKE CALCULATIONS a/
Parameter Standard Value Reference
Average body weight, adult 70 kg - EPA, 1980
Average body weight, child 10 kg ICRP, 1975
Amount of water ingested
daily, adult 2 liters MAS, 1977
Amount of water ingested
daily, child 1 liter NAS, 1977
Amount of air breathed
daily, adult 20 a1 EPA, 1980
Amount of air breathed 5 m3 FDA, 1970
daily, child
Amount of freshwater fish
consumed daily, adult 6.5 g EPA, 1980
a/ Example 1: Applying the standard assumptions.
Human Intake Factor = 2 liters/day water consumption * 70 kg body weight
= 0.029 liters/kg/day.
If contaminant concentration is 3 mg/liter in drinking water:
Human Intake Factor x 3 mg/liter = 0.086 mg/kg/day intake.
Example 2: Applying adjusted assumptions.
If site data indicate that the exposed population has a water consumption
rate of 1.2 liters/day and an average weight of 60 kg:
Human Intake Factor = 1.2. liters/day * 60 kg = 0.02 liters/kg/day.
If the contaminant concentration is 3 mg/liter in drinking water:
Human Intake Factor x 3 mg/liter =0.06 mg/kg/day intake.
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OSWER Directive 9483:00-2
6-12
adjustments based on more accurate intake and body weight information for the
potentially exposed population. For example, higher than average fish
consumption may be important for some sites where surface water contamination
is a possible problem. In addition, the standard intake values do not account
for reduced intakes resulting from human activity patterns that reduce human
contact with the contamination (i.e., it is assumed that exposure occurs 24
hours per day for the entire period that contamination is present). This
conservative approach can be modified based on site-specific information to .
the contrary. For example, if an industrial area is an inhalation exposure
point, it may be appropriate to adjust the standard intake factor by the
fraction of a year spent at the exposure point.
6.2.1 Calculate Ground-Water Intakes
Human exposure to contaminated ground water can occur when contaminated
wells are used as a drinking water source. The degree of exposure depends on
the concentration of the contaminant in drinking water, the amount of water
consumed per day, and the duration of exposure. The measured or predicted
concentrations (short-term and long-term) of each contaminant in ground water
at each exposure point are given in Worksheet 5-3. Insert these values 'into
appropriate columns of Worksheets 6-2 and 6-3. Note that separate worksheets
must be prepared for each ground-water exposure point. Using Exhibit 6-2
and/or other available information, calculate a standard human intake
coefficient for use in determining drinking water exposures. The intake
coefficient is calculated by dividing the average drinking water intake by the
average body weight to give a value in 1/kg/day. This coefficient is then
inserted into Worksheets 6-2 and 6-3.
Using Worksheets 6-2 and 6-3, estimate subchronic and chronic drinking
water intakes for each indicator chemical at all relevant ground-water
exposure points. Include the duration of exposure.
6.2.2 Calculate Surface Water Intakes
For potential exposures to contaminated surface water, calculate intakes
from ingestion of drinking water and ingestion of contaminated fish, as
appropriate for the site being assessed.
Drinking Water. Human exposure to contaminated surface water can occur
when the surface water is used as a drinking water source. The degree of
exposure to contaminants present in drinking water derived from surface water
depends on the same factors described for drinking water derived from ground
water. Obtain the concentrations (short-term and long-term) of each chemical
present in surface water at each exposure point from Worksheet 5-3. Insert
these values into the appropriate columns of Worksheet 6-4 and 6-5. The
standard human intake coefficient for drinking water is the same as that used
for calculating ground-water intakes (1/kg/day). Using Worksheets 6-4 and
6-5, estimate subchronic and chronic drinking water intakes for each indicator
chemical at all relevant surface water exposure points. Include the duration
of exposure.
-------
WORKSHEET 6-2
SUIICIIKONIC CKOUNO-WAfER INTAKES
4S1RUC1IONS:
1. Indicate exposure point anil estimated duration nl exposure. Duration should
correspond to whether intake is snlichtonic or chiornc (e.g., 3 months for
stibchronic and 70 years Tor chronic).
2. Using Exhibit 6-2 and/or other available information, calculate a 'human
intake factor by dividing ground-water intake per clay by body weight (e.g..
2 l/day/70 kg = 0.029 I/kg/day).
3. List all indicator chemicals (use additional worksheets if necessary) and their
short-term concentrations in ground water (from HOikshcet !>-3).
<4. Determine Stibchronic Daily Intake (SOI) using tin; following formula:
SOI = Human Intake factor x Short-lenn Concentration.
Facility ID:
Cluster/lank System:
Date;
Analyst:
Qua I i ty Com ro I:
Exposure Point: Nearest residences' private wolls
Duration of Exposure: 30 days
Population: 100
Human Intake factor (I/kg/day):
I/day/70 ker flepres.
03 0,02
0 0.
Lower
.00029
0
Upper
,0082
0
Repres.
,00.58
0
-------
WOHKSIIfET 6-3
CllltONIC GROUND-WATER INTAKES
INSTRUCT IONS:
1. Indicate exposure point and estimated duration or exposure. Duration should
correspond to whether intake is subchronic or chronic (e.g., 3 months Tor
subchronic and 70 years for chronic).
2. Using Exhibit 6-2 and/or other available inTo mini ion, calculate a human
intake factor by dividing ground-water intake per day by body weight (e.g., 2 I/day
//O kg = 0.029 I/kg/day).
3. ' tist all indicator chemicals (uso additional worksheets if necessary) and their
long-term concentrations in ground water (from Worksheet 5-3).
>l. Determine Chronic Daily Intake (GDI) using the following formula:
GUI = Human Intake Factor x Long-Term Concentiat ion.
FaciIjty ID:
Cluster/lank System:
Onto:
Annlyst:
Qua Ii ty Control:
Exposure Point: Nearest
Duration of Exposure: 50
Chemica 1
1 . Benzene
2. Lead
3.
residences' private wells
years Human Intake
Exposure Point
. Long- Term Concentration
1 mo/ 1 I
Lower Upper Rep res.
0,0001 0.003 0.002
00 0
Population: 100
Factor (l/kg/day): 2 1 /day/70 kq
Oa i ly Intake
(ma/kq/day)
Lower Upper
.000029 .00087
0 0
= 0.029 l/kq/dav
Rep res.
,00058
0
1.
5.
-------
WORKSHEET 6-5
CIIKUNIC SURFACE WATER INTAKES
1. Indicate exposure point and estimated duration of exposure. Duration should
correspond to whether intake is subchronic or chronic (e.g., 3 months for
subchronic and 70 years for chronic).
2. Using Exhibit 6-2 and/or other available infoii«.>i ion, calculate a human
intake factor by dividing surface water intake %0r day by body weight
(e.g., 2 l/day/70 kg = 0.029 I/kg/day).
3. list all indicator chemicals (use additional woiksheets if necessary) and their
long-term concentrations in surface water (from Worksheet 5-3).
4. Determine Chronic Daily Intake (CDI) using the following formula:
GDI = Human Intake Factor x Long-Term Concentration.
facility ID:
Cluster/lank System:
D.I to:
Analyst:
Qua)i ty Control:
Exposure Point: City residences
Duration of Exposure: 50 years
Chemical
1 . Benzene
2. Lead
Population: 100
Human Intake Factor (1/kq/dayV: 2 l/dny/70 kq - O.029 l/kq/day
t~X|>osuie Point '
Long-leim Concentration Daily Intake
(m
-------
WORKSHEET 6-*l
SUIICIIRONIC SURFACE WATER INIAKES
INSTKUCIIONS:
1. Indicate exposure point and estimated duration or exposure. Duration should
correspond to whether intake is subchronic or chronic (e.g.. 3 months for
subchronic and 70 years Tor chronic).
2. Using Exhibit 6-2 and/or other available infoimaiion. calculate a human
intake factor by dividing surface water intake per day by body weight
(e.g.. 2 l/day/70 kg = 0.029 I/kg/day).
3. list all indicator chemicals (use additional worksheets if necessary) and their
short-term concentrations in surface water (front Worksheet 3-3).
l|. Determine Subchronic Daily Intake (SDI) using tlu; following formula:
SDI = Human Intake factor x Short-Term Concentration.
faci I i ty II):
Cluster/Tank System:
Date:
Analyst:
Qua Ii ty Control:
Exposure Point: Cit
Duration of Exposure:
Chemica 1
1 . Ocnzene
2. Lead
3.
1.
5.
v residences Populat
30 days Human Intake Factor (I/kg/day):
Exposure Point
Short-lcnu Concentration
( ma/ I »
Lower Upper Rep res. Lower
0.001 0,03 0.02 .000029
000 0
ion: 100
2 l/day/70 kg - 0.029 1 /kg/day
Da i ly Intake
(ma/kg/day)
Upper Hopres.
.00087 J_00(i
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OSWER Directive 9483.00-2
6-17
Fish Consumption. Another potential'route of exposure from contaminated
surface water is through the ingest ion of contaminated fish. The factors that
determine human exposure from contaminated fish are the contaminant
concentration in. the fish, the amount of fish consumed, and the duration of
exposure. The concentration of a contaminant in fish can be estimated by
multiplying the estimated concentration of the contaminant in surface water by
the fish bioconcentration factor for that chemical. Obtain surface water
concentrations for each chemical at each exposure point from Worksheet 5-3.
Insert the appropriate values into the appropriate columns of Worksheets 6-6
and 6-7. Standard human intake coefficients are calculated by dividing
standard freshwater fish intake per day by the average adult body weight.
Obtain the fish bioconcentration factor for each chemical from Appendix C or
other sources. Using Worksheets 6-6 and 6-7, estimate subchronic and chronic
daily intakes (kg fish/kg body weight/day) from contaminated fish for each
indicator chemical at all relevant surface water exposure points. Include the
duration of exposure (i.e., the averaging time used for the short- and
long-term exposure point concentrations).
6.2.3 Calculate Air Intakes
As discussed in Chapter 5, significant air risks are only expected when
the hazardous waste constituents are highly volatile. Therefore, the
reduction in direct air risk that secondary containment provides will
generally be relatively small compared to the reduction in ground water and
surface water risks. Consequently, extensive assessment of direct air intakes
is unlikely to be required at most sites. Some situations will exist,
however, where direct air risk (e.g., from volatile chemicals on soils-) and
indirect air risk (e.g., from showering in water contaminated with volatile
chemicals) may be substantial and, therefore, must be considered.
Human intake of contaminants present in the air is dependent on the
contaminant concentration, the frequency and volume of inhalation, the
duration of exposure, and, in the case of particulates, particle size. The
measured or predicted air concentrations (short-term and long-term) of each
contaminant at specific exposure points are given in Worksheet 5-3. Insert
these values into the appropriate columns of Worksheets 6-8 and 6-9. Note
that a separate worksheet must be prepared for each inhalation exposure
point. Using Exhibit 6-2 and/or other available information, calculate a
standard human intake coefficient for use in determining air exposures. This
value takes into account the frequency (breathing rate), volume, and duration
of inhalation intake as well as an average human body weight. The intake
coefficient is calculated by dividing the average daily air intake by the
average body weight to give a value in m3/kg/day. Insert the calculated
coefficient into Worksheets 6-8 and 6-9.
Using Worksheets 6-8 and 6-9, estimate subchronic and chronic air intakes
for each indicator chemical at all relevant exposure points. Include the
duration of exposure. Note that absorption of chemicals into the body is not
accounted for by the intake estimates (or by the critical toxicity values
described in the latter part of this chapter). Therefore, if chemical-
specific absorption data are available, they can be used to refine the
assessment as long as the procedures and values are clearly documented.
-------
WORKSHEET 6-6
SUIiCIIRONIC FISH INTAKES
INSTRUCTIONS:
I. Indicate exposure point and estimated duration of exposure. Duration should
correspond to whether intake is subchronic or chronic (e.g., 3 months Tor
subchronic and 70 years for chronic).
2. Record the b ioconcentra t ion factor (BCf) for aactt chemical (from Appendix C).
3. Using Exhibit 6-2 and/or other available infoim.ii ion, calculate a human
intake factor by dividing fish intake pur day by body weight (e.g., 6.5 gm/day/
70 kg x IE-3 kg/gm = 9.3E-5 kg/kg/day).
-------
WORKSIILEl 6-7
CHRONIC fISII INIAKES
INSIHUCrIONS:
1. Indicate exposure point and estimated duration of exposure. Duration should
correspond to whether intake is subclircnic or chronic (e.g., 3 months for
subchronic and 70 years Tor chronic).
2. Record the bioconcentrat Ion factor (BCF) for each chemical (from Appendix C).
3. Using Exhibit 6-2 and/or other available inloim,u ion, calculate a human
intake factor by dividing fish intake par day by body weight (e.g., 6.5 gm/day
/70 kg x 1E-3 kg/gm = 9.E-5 kg/kg/day).
<4. List all indicator chemicals (use adiJiiion.il woikshcets if necessary) and their
long-term concentrations in surface water (from Worksheet 5-3).
5. Determine Subchronic Daily Intake (SDI) using the following formula:
SDI = Human Intake Factor x DCf x Long-lerui Concentration.
faciIi ty ID:
Cluster/Tank System:
Date:
Annlyst:
Qua Ii ty Control:
Exposure Point: Genera
Duration of Exposure:
Chemical
1 . Benzene
2. Lead
3.
1 population
50 years
BCf
(I/kg)
5.2
Human Intake factor
Exposure Point
Short-lenn Concentration
(mq/l)
Lower Upper Repres.
0.001 0.03 0.02
00 0
Population: 20
(kq/kq/dav): 6.5E-3 kq/dav/70 kq =
Daily Intake
(mq/kq/day)
Lower Upper
,OQOOOOi|8 ,000015
0 0
9.3L-5 kq/kq/dav
Repres.
. 00009 7
0
5.
-------
WORKSHEET 6-8
SimCHRONIC AIR INIAKES
INSTRUCTIONS;
1. Indicate exposure point and estimated duration or exposure. Duration should Facility ID:
correspond to whether intake is suhchronic or chronic (e.g., 3 months for
subchronic and 70 years for chronic). Cluster/Tank System:
2. Using Exhibit 6-2 and/or other available infoi ni.it ion. calculate a human Onte:
intake factor by dividing air intake per day by body weight (e.g.. 20 ml/day
/10 kg = 0.29 mJ/kg/day). Analyst:
3. List all indicator chemicals (use additional woiK&hoets IT necessary) and their Quality Control:
short-term concentrations In air (from Worksheet *>-3).
osiire Point
Short-IIM in Concentration Daily Air Intake
Chemical l!0!l/!!>3J (mg/kg/dav)
Lower U|»por Wepres. Lower Upper Repres.
1.
2.
3.
Benzene
Lead
0.01 0.3
0 0
0.2
0
.0029
0
.087
0
.058
0
5.
-------
WORKSHEET 6-9
CHRONIC AIR INIAKES
I. Indicate exposure point and estimated duration or exposure. Duration should
correspond to whether intake is siibchronic or chronic (e.g., 3 months Tor
subchronic and 70 years Tor chronic).
2. Using Exhibit 6-2 and/or other available information, calculate a human
intake factor by dividing air intake per day by body weight (e.g., 20 m3/day
/70 kg = 0.29 m3/kg/day).
3. List all indicator chemicals (use additional worksheets if necessary) and their
long-term concentrations in air (from Worksheet b-3).
-------
OSWER Directive 9483.00-2
6-22
6.2.4 Calculate Intakes From Other Exposure Pathways
There are a number of other potentially important exposure pathways that
are more difficult to quantify than those just described. Nevertheless, the
human chemical intakes received through such pathways may be extremely
important to certain populations at risk. For example, exposure may be by
dermal absorption or direct ingestion of soil that has been contaminated by
surface runoff.'-1 Another potential exposure pathway could be agricultural
land being irrigated with contaminated surface or ground water; human exposure
would occur if produce is contaminated and ingested. Humans may also be
exposed via consumption of game animals that reside in contaminated areas.
Contaminated surface waters, in addition to providing dfinking water, may be
used for recreation and, therefore, humans may be exposed by swimming in such
waters. This use may result in dermal, oral, and inhalation exposures.
During bathing or showering, dermal or inhalation exposure may occur.10-1
Volatilization while washing dishes or cooking with contaminated water may
result in oral and inhalation exposure. If these additional intakes were not
addressed in previous sections, they should be addressed here.
Formulas for these less common exposure pathways have not been included in
this manual because there has been little experience on which to base standard
formulas. It should be noted, however, that at certain sites and for certain
populations at risk, these less common routes of exposure may be significant.
Therefore, Worksheets 6-10 and 6-11 have been provided to allow calculation of
these other intakes (e.g., inhalation while showering, exposure to soil,
dermal exposure or surface water ingestion while swimming). If one of these
exposure pathways has been identified as significant, then, for guidance on a
method for calculating chemical intakes, contact the Exposure Assessment
Group, Office of Research and Development, U.S. EPA, 401 M Street, S.W.,
Washington, D.C. 20460.
6.2.5 Combine Pathway-Specific Intakes to Yield Total Oral and
Total Inhalation Intakes
In this step, total exposure scenarios are developed for each exposure
point, and the relevant route-specific intakes are combined for the affected
*J This route of exposure is especially important for children playing
outdoors. If young children will have access to an area with contaminated
surface soil, exposure for this subpopulation via soil ingestion can be
estimated based on the following assumptions: (1) ingestion is primarily of
concern for children between age two and six; (2) ingestion rate varies from
0.1 to 5 grams per day, with higher values representative of pica behavior;
and (3) body weight of children in this age group averages 17 kg, and ranges
from 10 to 25 kg. These assumptions are based on U.S. EPA (1984), Kimbrough,
et al. (1984), and Anderson, et al. (1984).
10J Recent studies indicate that intake of volatile chemicals due to
showering in contaminated water may be greater than intake from drinking the
contaminated water. For a reference list and recent review, see the
following: Foster, S.A. and Chrostowski, P.C., Integrated Household Exposure
Model for Use of Tap Water Contaminated with Volatile Organic Chemicals,
ICF-Clement Associates, Inc., Washington, D.C., June 1986".
-------
WORKSHEET 6-10
OIIILR SUBCIIRONIC INIAKES
IHSIHUCIIONS:
1. Indicate exposure paint, type or intake, ami est im.i toil duration of
exposure. Duration should correspond to whether intake is subclironic
or chronic (e.g., 3 months for subclironic and 70 years Tor chronic).
2. Using Exhibit 6-2 and/or other available infonnation, calculate a human
intake factor.
3. List all indicator chemicals (use additional worksheets if necessary) and their
short-term concentrations (from Worksheet 'j-J).
>l. Determine Subchronic Daily Intake (SOI) using the following formula:
SOI = Human Intake Factor x Short-Terra Concentration.
fac i I i ty II):
Cluster/lank System:
Date:
Analyst:
Qua Ii ty Control:
Exposure Point: Nearest residences Population: 100
Duration of Exposure: 30 days Human Intake Factor:
Exposure Point
Chemical Short-Teiin Concentration"
tower Upper Repres. Lower
1. Benzene 0.001 0.03 0.02 .00029
2. Lead 000 0
Intake: Soil inhalation
20 m3/day//0 kq = 0.29 mS/kg/day
Da i ly Intake
(mij/kqyday)
Upper Reprcs.
.0087 .00r>8
0 0
3.
14.
5.
Air concentrations, in mg/ml.
-------
WORKSHEET 6-11
OIIIER CHRONIC INTAKES
INSTRUCTIONS;
1. Indicate exposure point, type or intake, anil <;si im/iiud duration of
exposure. Duration should correspond to whether intake is stibcliroriic
or chronic (e.g., 3 months for subchronic and 70 yi.-nrs for chronic).
2. Using Exhibit 6-2 and/or other available infix maiion, calculate a human
intake factor.
3. List all indicator chemicals (use additional worksheets if necessary) and their
long-term concentrations (from Worksheet 'j-J).
4. Determine Chronic Daily Intake (CDI) using the following formula:
CDI = Human Intake Factor x Long-Term Concentration.
facility 10:
Cluster/Tank System:
Date;
Analyst:
Qua Ii ty Control:
Exposure Point: Nearest residences
Duration of Exposure: 50 years
Lxposure Point
Chemical Long-Turin Conceritrai
Lower Upper
1. Benzene O.ooui 0.00}
2. Lead 0 0
3.
Population: 100 Intako
Human Intake Factor: 20 m3/day/70 kq = 0.
Da i ly Intake
ion (raq/kg/day)
Repres. Lower Upper
0,002 ,000029 ,00087
'0 00
So i 1 i nha 1 a t i on
29 inj/ktj/dav
Rupres.
. 00058
0
«l.
5.
* Air concentrations, in mg/m3.
-------
OSVER Directive 9483.00-2
6-25
population. This exposure summation gives the total daily oral intake and
total daily inhalation intake of each chemical to which the population may be
exposed.
In Chapter 5, chemical concentrations at the significant exposure points
were estimated for each identified exposure pathway (see Worksheets 5-1 and
5-3). Recall chat the significant exposure point for a pathway is the point
of highest individual exposure, although locations with large exposed
populations and lower exposure levels should also be included in' the analysis
as supplementary exposure points. Now the task is to determine, for each
significant exposure point identified in Chapter 5, which of the other
exposure pathways could contribute to total exposure at that point. Use
Worksheet 6-12 to record this information. Be sure to list- any potentially
important non-quantified exposure pathways on Worksheet 6-12. If the
populations at risk for different exposure pathways are mutually exclusive, do
not sum intakes from both pathways for the same exposure point. For example,
it is incorrect to sum the intakes associated- with ingesting, drinking water
from different sources if each person's exposure is exclusively from one of
the sources.
After a total exposure scenario has been developed for each significant
exposure point (e.g., a population living near the site with private drinking
water), combine the individual chemical intakes calculated for each of the
oral exposure pathways identified for that exposure point. Do the same for
inhalation. Referring to Worksheet 6-12, insert the appropriate intakes to be
combined (from Worksheets 6-2 through 6-11) into Worksheet 6-13 (SDIs) and
Worksheet 6-14 (CDIs). Note that some intake values from Worksheets 6-2
through 6-11 may need to be adjusted when-applied to exposure points other
than those specified. In situations where the significant exposure points of
two pathways are relatively far apart, one must judge whether the additional
calculation effort is warranted or whether simply summing the intakes for the
significant exposure points is sufficient. For example, if the significant
exposure points for an air and a ground-water pathway differ, one may choose
either to adjust the intakes from Worksheets 6-2, 6-3, 6-8, and 6-9 before
using them for a total exposure estimate or combine the unadjusted intakes for
a conservative total exposure estimate.
The next step in the summation procedure is to add the intakes from
drinking water, fish, and other oral ingestion for each chemical to give the
total oral SDI (Worksheet 6-13) and GDI (Worksheet 6-14) for the population
at risk at each significant exposure point. The existence of any
non-quantified exposure pathways should be noted on these summary intake
worksheets. In addition, be sure to note the number of people exposed at each
significant exposure point.
The intake summation procedure described here is most relevant to the
estimation of total chronic exposure levels. When estimating total subchronic
exposures, be sure not to sum peak intake values estimated for different time
periods for the same release. Remember, the time period defined as short-term
is anywhere from a 10 to a 90 day period. If the SDI for one pathway is
estimated to occur immediately and the SDI for another pathway affecting the
same exposure point from the same release is predicted to occur in 5 years, it
would be improper to sum these (they would affect the same population, but at
-------
OSWER Directive 9483.00-2
6-26
WORKSHEET 6-12
PATHWAYS CONTRIBUTING TO TOTAL EXPOSURE
INSTRUCTION'S:
1. List the exposure points for all
exposure pathways being evaluated
(from Worksheet 5-1) (use additional
worksheets if necessary).
2. Determine the exposure pathways con-
tributing to total exposure for each
listed exposure point.
3. Note in the comments column which
exposure pathways are only short-term,
which are non-quantified, and any other
pertinent information.
Facility ID:
Cluster/Tank System:
Date:
Analyst:
Quality Control:
Exposure Point
Exposure Pathways
Contributing to
Total Exposure
Comments
1. Nearest downgradient
facilitv boundarv
Ground-water ingestion
Soil contact
Non-quantified
Air inhalation
2. Residences 1 mile SW on
vulnerable oublic wells
Ground-water ingestion
Air inhalation
Low exoosure
3. Hosoital at 2 miles on
Ground-water ingestion
public well (sensitive)
-------
WOKKSIIltl 6-13
IOIAI StmCIIHONIC OAIIY INTAKE (Sl)l)
INSTRUC1IONS:
1
Indicate exposure point, number of people, .11 id whether intake
estimates are lower, representative, or upper values
(complete a separate worksheet Tor each type of estimate).
2. List all indicator chemicals (use additional woikslioets if necessary).
3. He,for to Worksheet 6-12 and determine which exposure pathways are
relevant Tor the exposure point.
l«. Record SOIs (in mg/kg/day) for the exposure point from Worksheets 6-2,
6-U, 6-6, 6-fl, and 6-10 in the appropriate columns.
5. Determine total SDI by adding the component SI)Is Cor each chemical.
Tor example, ground-water, surface water, nnd fish intakes would
sum together Tor total oral SDI.
fac iIi ty 10:
Cluster/Tank System:
Date:
Analyst:
QunIi ty Control;
Exposure Point:
Intake Estimates
Chemica 1
1 . Benzene
2. Lead
3.
Nearest residences on private we
(circle one): Lower Upper
Ground Surface
Water Water
SDI SDI
0,0058
0.0013
Ms
Represents t i vc
fish Other
Ingest ion Oral.
'SOI SOI
. OOOO'i?
.0000038
Population: 100
lotal Other lotal
Oral Air Inhalation Inhalation
SDI SOI SDI SDI
0.0058 - - O
0.0013 - - 0
U.
5.
-------
WORKSIIEEI 6-111
IUIAI CHRONIC DAILY INIAKC (Cl)l)
INSIRUCI IONS;
1. Indicate exposure point, number or people, and whether intake
estimates are lower, representative, or upper values
(complete a separate worksheet For each type of estimate).
2. List all indicator chemicals (use additional worksheets if necessary).
3. Refer to Worksheet 6-12 and determine which exposure pathways are
relevant Tor the exposure point.
>t. Record GDIs (in mcj/kg/day) for the exposure point from Worksheets 6-3,
6-5, 6-7, 6-9, and 6-11 in the appropriate columns.
5. Determine total CD) by adding the component CD Is for each chemical.
For example, ground-water, surface water, and fish intakes would
sum together Tor total oral GDI.
Exposure Point: Nearest residences on private wells' Popula
Intake Estimates (circle one): lower Upper Representative
1 .
2.
3.
1.
5.
Ground Surface Fish Other Total
Water Water Inyostion Oral Oral
Chemical CDI GDI GDI GDI GDI
Uenzene 0,0008 - . OOOOOOIJ - o 0008
Lead 0.0009 - .00000018 - 0.0009
f ac i 1 i ty ID:
Cluster/lank System:
Date;
Ann lyst :
Qua 1 i ty Control :
-
tion: 100
Other Total
Air Inhalation Inhalation
COI GDI CDI
0
0
'
-------
OSWER Directive 9483.00-2
6-29
different times). In this situation, assessing short-term risks based on the
higher of the two values usually will provide a reasonable assessment of
short-term risks. Alternatively, if releases can occur from the same or
different systems and result in SDIs from two different (or the same) pathways
at the same time, then the total exposure would be the summation of these
individual SDIs.
6.3 DETERMINE CHEMICAL TOXICITIES
The determination of whether or not a chemical poses a hazard to humans is
crucial to the evaluation of the chemical's possible health effects.
Information on toxicity must be used in conjunction with data on estimated
intakes to characterize risk. Critical toxicity values for many common toxic
substances, as documented in the Superfund Public Health Evaluation Manual,
are presented in Appendix C of this guidance. Toxicity information for
specific chemicals not listed in Appendix C is available through the
Environmental Criteria and Assessment Office (ECAO), U.S. EPA, 26 W. St. Clair
Street, Cincinnati, Ohio 45268. In some cases, it may be necessary to derive
appropriate values based on available toxicological or epidemiologic data.
Three values that describe the degree of toxicity posed by a chemical are
required in the evaluation of possible health effects:
the acceptable intake for subchronic exposure (AIS)11J;
the acceptable intake for chronic exposure (AIC)llJ;
and
the carcinogenic potency'factor (for potential
carcinogenic effects only).
These values are based on empirical data and have not been adjusted for
site-specific conditions. In some cases, separate critical toxicity values
will be available for ingestion and inhalation routes of exposure. These
values are provided in Appendix C for many chemicals.
AIS and AIC values are required for all chemicals being evaluated. These
values are derived from quantitative information available from studies of
animals (or observations made in human epidemiologic studies) that examine the
relationship between intake and non-carcinogerric toxic effects. They are
designed to be protective of sensitive populations. For example, for
teratogenic chemicals, AIS values are generally derived for the teratogenic
effects.
If a chemical has a verified reference dose (RfD), that value^should be
used as the AIC.12J Verified RfDs are for noncarcinogenic effects and are
11J The terms "AIC" and "AIS" are defined here only for the purposes of
this evaluation.
12J For chemicals without EPA-verified RfD values, AIC values may be
developed from other sources, such as EPA's Health Effects Assessment
documents.
-------
Directive y4.6j.uu-/
6-30
similar in concept to acceptable daily intakes (ADIs). In general, RfDs are
based on the most sensitive effect resulting from chronic exposure. RfDs are
being verified by an EPA Work Group chaired by the Office of Research and
Development, in a process begun in 1985; they currently are available for
approximately 100 chemicals.
AIS values are determined by a process similar to that used to develop
RfDs, except that subchronic studies are the basis of the values instead of
chronic studies. Most AIS values are based on subchronic animal studies (10
to 90 days), although some are derived from human exposure data. For
chemicals without appropriate human data, the highest subchronic exposure
level not causing adverse effects, or the "no observed -adverse effect level"
(N'OAEL), is determined from all of the animal studies available in the
literature. The NOAEL is then divided by appropriate uncertainty factors to
derive the AIS. Uncertainty factors usually include a factor of ten to
account for extrapolation from animal experiments to human effects and a
factor of ten for intraspecies variability (i.e., to account for the fact that
two individuals of the same species may not react to the same quantity of a
chemical with the same level of response).
AIC values are usually based on long-term animal studies. Adequate human
data are available for a few chemicals, and these data are used whenever
possible. Literature values from all appropriate studies are used to
determine the highest chronic exposure level that does not cause an adverse
effect (NOAEL). As for the AIS determination, the NOAEL is divided by ten to
extrapolate from animal effects to human effects, and is divided by ten to
account for intraspecies variability. If sufficient data cannot be obtained
on chronic effects, subchronic NOAELs are used and divided by an additional
factor of ten to account for uncertainties caused by extrapolation from
subchronic to chronic effects.
The carcinogenic potency factor is an estimated upper 95 percent
confidence limit of the carcinogenic potency of the chemical. It is expressed
as the lifetime cancer risk corresponding to one milligram of chemical intake
per day per kilogram of body weight (mg/kg body weight/day) and it can be used
at low doses co estimate an upper bound of cancer risk for a chemical.
Generally only a limited amount of new work will be necessary to determine
chemical toxicities, as the assessment has already been done for many toxic
chemicals. Thus, for most cases, it is only necessary to summarize to'xicity
data already available. If EPA has completed verification of an RfD for a
specific chemical, it should be used as the AIC. If toxicity values are not
available in Appendix C, contact ECAO for guidance. Use Worksheet 6-15 to
summarize available data.
Three kinds of toxicity information should now have been gathered on each
chemical of concern. These are subchronic and chronic acceptable intakes for
noncarcinogenic effects, and carcinogenic potency factors for potential
carcinogenic effects. The information that has been gathered on toxicity can
be combined with data on estimated intakes to characterize long-term and
short-term health risks. The procedure for doing this characterization is
described in the next section.
-------
OSWER Directive 9483.00-2
6-31
WORKSHEET 6-15
CRITICAL TOXICITY VALUES
INSTRUCTIONS:
1. List all components of the waste or
indicator chemicals (use additional
worksheets if necessary).
2. List subchronic acceptable intake (AIS),
chronic acceptable intake (AIC), and car-
cinogenic potency factor values (includ-
ing carcinogenicity weight-of-evidence
ratings).
3. For teratogenic chemicals (indicated in
Appendix C), list a separate AIS for that
effect only.
Facility ID:
Cluster/Tank System:
Date:
Analyst:
Quality Control:
AIS
Chemical (mg/kg/day)
Inhalation Route:
1. Benzene
2. Lead
3. Methvl ethvl ketone 2.2
Ingestion Route:
1. Benzene
2. Lead
3. Methvl ethyl ketone
Carcinogenic
AIC Potency Factor
(mg/kg/day) (kg-day/mg)
0.026(A) a/
0.00043 NA
0.22 NA
0.052(A) a/
0.0014 NA
0.050 NA
a/ EPA weight-of-evidence rating in parentheses for potential carcinogens
(provided in Appendix C).
NA
not applicable.
-------
OSWER Directive 9483.00-2
6-32
6.4 RISK CHARACTERIZATION
This step involves a comparison for noncarcinogens between the projected
intakes determined in Section 6.2 and the acceptable intakes calculated in
Section 6.3. For carcinogens, projected intakes from Section 6.2 are
converted to carcinogenic risks and compared with a target risk for total
exposure to carcinogens. The methodology for making each of these comparisons
is different, so these two classes of toxicity are discussed separately in the
remainder of this section. Exposure point concentrations have already been
compared to established quality standards in Section 6.1 for those chemicals
that have such standards; these comparisons will be combined with the risk
characterization results in the overall health effects evaluation.
6.4.1 Noncarcinogenic effects
The overall process for evaluating noncarcinogenic effects is illustrated
in Exhibit 6-3. If the hazardous waste tank for which the application is
being submitted contains only one constituent of concern, the comparison
between projected intake and acceptable intake is straightforward. If the
projected intake is lower than the acceptable intake, no adverse health
effects will be expected. If the projected intake exceeds the acceptable
intake, adverse health effects may be anticipated.
In most cases, hazardous waste tanks will contain a number of constituents
of concern. If this number is large, the applicant may have selected
indicator chemicals to represent the wastes as described in Section 2.2 and
these indicator chemicals should be evaluated here. If the intake of any
constituent is greater than its acceptable intake for subchronic exposure
(AIS) or acceptable intake for chronic exposure (AIC), then an adverse health
effect is likely. If this is not the case, then the ratios of daily intake
to acceptable intake (one for each chemical) summed for each pathway of
exposure (e.g., oral, inhalation) at each exposure point. This procedure
should be followed for both chronic and subchronic exposures.
As a first approach co risk characterization for several noncarcinogenic
chemicals and effects, the assumption should be made that subthreshold
exposures to the chemicals are additive and in total may cause an adverse
effect. This approach reflects the Hazard Index approach presented in the
Guidelines for the Health Risk Assessment of Chemical Mixtures (51 Federal
Register 34014-34025, September 24, 1986). Hazard Indices are evaluated for
each exposure point and are calculated as follows:
Subchronic Hazard Index1'-1 = SDI, + SDI- + + SDI
i z i
AIS1 AIS2 AIS^
where SDI. = subchronic daily intake calculated for the ith
toxicant at an exposure point, and
acceptable intake for subchronic e>
ith toxicant at an exposure point; and
AIS. = acceptable intake for subchronic exposure to the
IJJ Ratios should be summed only for chemicals and exposure pathways for
which the short-term concentration time period is the same.
-------
OSWER Directive 9483.00-2
Exhibit 6-3
DECISION TREE FOR THE EVALUATION OF
POTENTIAL NONCARCINOGENIC EFFECTS
How many constituents of concern
does the tank contain?
Does projected intake
exceed the
acceptable intake?
Yes
Does projected intake
exceed acceptable intake
for any individual chemical?
No
No
Yes
No
Does either the subchronic
or chronic hazard index
exceed one?
Yes
Separate chemicals by
critical effect and calculate
separate hazard indices for
each effect. Do any of the
hazard indices exceed one?
Adverse health effects
are unlikely.
No
Adverse health effects
are possible.
Yes
-------
OSWER Directive 9483.00-2
6-34
Chronic Hazard Index = CDI1 + CDI2 + +
AIC1 AIC2 AICi
where GDI. = chronic daily intake calculated for the ith toxicant
at an exposure point, and
AIC. = acceptable intake for chronic exposure to the ith
toxicant at an exposure point.
If either hazard index does not exceed one, then adverse health effects will
likely not be experienced, but if either index exceeds one, then further
analysis is necessary.
If the projected intake for any individual chemical of concern is greater
than its acceptable- intake, adverse health effects may be anticipated. The
assumption of additivity reflected in the hazard index equation is applied
most properly to chemicals that produce the same effect by the same
mechanism. Therefore, if the equation is applied to a mixture of chemicals
that produce different adverse effects, it is likely to overestimate the
potential for an adverse effect. Consequently, if the sum of the ratios of
daily intake to acceptable intake is greater than one, the chemicals should be
segregated by critical effect, and separate hazard indices should be derived
for each effect. Critical effects can be found in Health Effects Assessment
Documents available from ECAO, U.S. EPA, Cincinnati, Ohio. A list of-
chemicals for which these documents are available as of October 1986 can be
found in Appendix C, Exhibit C-7. Use Worksheets 6-16 and 6-17 to calculate
hazard indices for subchronic and chronic exposures, respectively.
Intakes and risks from oral and inhalation exposure pathways should be
estimated separately so that route-specific toxicity data in Appendix C can be
used. However, the possible effects of multimedia exposure should be
evaluated by summing the hazard indices for inhalation and oral exposures at
each exposure point. This procedure will ensure that acceptable levels are
not being exceeded by combined intakes when multiple exposure pathways exist.
It is emphasized that the hazard index is not a mathematical prediction of
incidence or severity of effects. It is simply a numerical index to help
identify potential exposure problems. Results for multiple chemicals should
not be interpreted too strongly. A hazard index greater than one for multiple
chemicals and effects indicates a potential for concern rather than a definite
problem. Although a hazard index greater than one for multiple chemicals with
the same effect is more indicative of a problem, uncertainty still exists
because of the additivity assumption.
If some of the chemicals do not have adequate toxicity information, thus
preventing their inclusion in the hazard index, the hazard index may not be
reflective of potential hazard from the tank. Consideration of chemicals that
do not have toxicity values could significantly increase the hazard index to
levels of concern. Professional judgment (e.g., from a toxicologist) is
required to determine how to interpret the hazard index for a particular tank.
-------
OSWER Directive 9483.00-2
6-35
WORKSHEET 6-16
CALCULATION OF SUBCHRONIC HAZARD INDEX
FOR EACH EXPOSURE POINT
INSTRUCTIONS:
1. Identify exposure point and sub-
chronic constituents of concern (use
additional worksheets if necessary).
2. List the total oral subchronic daily
intake (SDI) and total inhalation SDI
in the appropriate columns for each
chemical (in mg/kg/day).
Facility ID:
Cluster/Tank System:
Date:
Analyst:
Quality Control:
3. List route-specific subchronic acceptable intake (AIS) values and calculate
route-specific SDI:AIS ratios for each chemical.
4. Sum and record route-specific SDI:AIS ratios.
5. Sum and record total (oral plus inhalation) SDI:AIS ratios only if the
SDIs for the two routes refer to the same time period. If the sum is
greater than 1, it may be possible to separate the ratios according to
health endpoint and complete a separate worksheet for each endpoint.
Exposure Point:
Intake Estimates
Chemical
1. Xylene
2. Manganese
3.
Facility boundary Population: Future shoooing area
(circle one): Lower Upper Representative
Oral Inhalation
SDI AIS SDI:AIS SDI AIS SDI:AIS
0.008 0.1 .08 0.004 0.69 0.006
0.001 0.53 .002 0 0.003 0
4.
Sum of Oral SDI:AIS Ratios = .082
Sum of Inhalation SDI: AIS Ratios = .006
Sum Total of All Ratios = .088
-------
OSWER Directive 9483.00-2
6-36
WORKSHEET 6-17
CALCULATION OF CHRONIC HAZARD INDEX
FOR EACH EXPOSURE POINT
INSTRUCTIONS:
1.
2.
3.
Identify exposure point and chronic,
non-carcinogenic constituents of
concern (use additional worksheets
if necessary).
List the total inhalation chronic
daily intake (GDI) and total oral
GDI in the appropriate columns for
each for each chemical (in mg/kg/day)
Facili'ty ID:
Cluster/Tank System:
Date:
Analyst:
Quality Control:
List route-specific chronic acceptable intake (AIC) values and
calculate route-specific GDI:AIC ratios for each chemical.
Sum and record route-specific GDI:AIC ratios.
Sum and record total (oral plus inhalation) GDI:AIC ratios. If the sum is
greater than 1, it may be possible to separate the ratios according, to
health endpoint and complete a separate worksheet for each endpoint.
Exposure Point:
Intake Estimates
Chemical
1. Xylene
2 . Lead
Nearest residences Population: 1,000
(circle one) : Lower Upper Representative
Oral Inhalation
GDI AIC CDI:AIC GDI AIC GDI: AIC
0.004 0.01 0.04 0.002 0.4 0.005
0.001 0.22 0.005 0 0.003 0
3.
4.
Sum of Oral GDI: AIC Ratios = 0.045
Sum of Inhaltion GDI: AIC Ratios = 0.005
Sum Total of All Ratios = 0.050
-------
OSWER Directive 9483.00-2
6-37
6.4.2 Carcinogenic Effects
Risks for potential carcinogens are estimated as probabilities. The
carcinogenic potency factor, which is an upper 95 percent confidence limit on
the probability of response per unit intake of a chemical over a lifetime
(i.e., only 5 percent chance that the probability of response could be greater
than the estimated value on the basis of the experimental data used), is used
to convert estimated intakes to incremental risk. These carcinogenic potency
factors can be found in Appendix C, Exhibit C-4. Because the exposure
assessment is conservative, the resultant risk predicte.d is an upper-bound
estimate and may overestimate the actual risk from a release of contaminants
from a tank system. This method is used, however, because it is important not
to underestimate carcinogenic risk.
For the calculation of incremental risk from relatively low intakes, it
can be assumed that the dose-response relationship will be in the linear
portion of the dose-response curve. This procedure implies that the slope of
the dose-response curve is equivalent to the carcinogenic potency factor
(CPF). The relationship between risk and intake is given by the following
equation:
Risk = GDI x CPF
This equation is valid only at low risk levels. But because the risk-
based variance will likely not be granted when chemical intake and estimated
-4
carcinogenic risk are large (e.g., above 10 ), it would not be necessary to
calculate potential risk accurately. If the tank contains multiple chemicals,
assuming individual intakes are small, the risk equation is generalized to the
following:
Risk = I (GDI. x CPF.)
This equation is based on the assumption that there are no synergistic or
antagonistic chemical interactions and that all chemicals have the same type
of carcinogenic effect. If there is expected to be more than one route of
exposure, the total carcinogenic risk is assumed to be additive, that is:
Total carcinogenic risk for a chemical =
CDI(inhalation) x CPF(inhalation) + CDI(oral) X CPF(oral)
The total potential risk from a hazardous waste tank will be the sum of all
the total carcinogenic risks for each chemical contained in the tank at a
given point of exposure. Current Agency policy identifies a risk of 10* as
A * A.
the point of departure within a risk range of 10 to 10 for known or
suspected carcinogens. A target risk higher than 10 should be accompanied
by an appropriate justification. Worksheet 6-18 is provided for calculating
total potential carcinogenic risk.
6.4.3 Other Considerations
The calculations described above are based on a number of assumptions, and
there are many uncertainties inherent in the risk assessment process. Results
-------
OSWER Directive 9483.00-2'
6-38
WORKSHEET 6-18
CALCULATION OF POTENTIAL CARCINOGENIC RISKS
FOR EACH EXPOSURE POINT
INSTRUCTIONS;
1. Identify exposure point and
potentially carcinogenic consti-
tuents of concern (use additional
worksheets if necessary).
2. List- all exposure routes for each
chemical.
Facility ID:
Cluster/Tank System:
Date:
Analyst:
Quality Control:
3. Record chronic daily intake (GDIs) and carcinogenic potency factors
(including carcinogenicity weight-of-evidence; e.g., A, Bl, B2, etc.) for
each chemical and each exposure route.
4. Multiply the potency factor by the GDI to get the route-specific risk; then
sum the route-specific risks for each chemical.
5. Sum all of the chemical-specific risks to give an estimate of total
incremental risk due to potential carcinogens.
Exposure Point: On-Site
Population: 20
Intake Estimates (circle one): Lower Upper Representative
Exposure
Chemical Route
Carcinogenic Route-
GDI Potency Factor specific
(mg/kg/day) (kg/day mg) Risk
Total
Chemical-
specific
Risk
1. Benzene
Oral
2.5E-4
Inhalation 1.2E-3
5.2£-2(A) 1.3E-5
2.6E-2CA) 3.1E-5
4.4E-5
2.
TOTAL UPPER BOUND RISK = 4.4E-5
-------
OSWER.-Directive 9483.00-2
6-39
that show intakes or risks below the target intakes or risk levels do not
necessarily mean that a risk-based variance should be granted. Other
available information must first be considered and professional judgment
applied to each variance petition.
If indicator chemicals have been used in the risk assessment, it is
important to reevaluate the choice of these chemicals and determine whether
any information has been uncovered that suggests the need to include other
chemicals in the assessment. Care should be taken to include any chemicals
that are known to have a synergistic effect. A literature search should be
performed to determine if there is any evidence for synergism of the chemicals
being evaluated. When specific data are available that support a synergistic
effect between two or more chemicals contained in the hazardous waste tank,
these data should be considered carefully and the risk assessment modified
accordingly. However, the compounds in a mixture may also interfere with the
synergism of chemicals. If data on chemical interactions are available but
are not adequate to support a quantitative assessment, they should be
considered after completion of the risk assessment as factors that may affect
the risk.
-------
OSVER Directive 9483.00-2
CHAPTER 7
ENVIRONMENTAL IMPACT EVALUATION
This chapter is-designed to be used to evaluate risks to the environment
in the event of releases of waste constituents from hazardous waste tanks
without secondary containment. To evaluate environmental risks for this final
phase of the risk-based variance procedure, a comparison is made between
projected environmental exposure levels of indicator chemicalsIJ and the
harmful levels of these chemicals for animals, plants, and physical
structures. The exact nature of this comparison depends upon needs and
conditions at individual sites. If water quality criteria "are available for
all indicator chemicals, this evaluation is based on a comparison of
environmental receptor exposure point concentrations, as determined using
Worksheet 5-4, to the relevant water quality criteria as described in Section
7-. 1.
If general water quality criteria are based on irrelevant species or may
be affected by site-specific aquatic chemical conditions, then more
appropriate site-specific criteria can be derived based on guidance in Section
7.2 for either aquatic or terrestrial exposures. It is not likely that
derivation of site-specific criteria will be necessary for most sites. If a
criteria is not available for a particular chemical, then the applicant will
be expected to include any available relevant environmental information that
may exist. Regardless of whether general water quality criteria or site-
specific criteria are used, the ratios of environmental receptor exposure
point concentrations and criteria for all chemicals at each exposure point are
added together based on the assumption that multiple sub-threshold exposures
may result in an adverse effect and that the magnitude of the adverse effect
will be proportional to the sum of the ratios of the sub-threshold exposures
to criteria. Finally, Section 7.3 provides limited guidance on field
evaluations that can be used to characterize environmental threats if the
criteria comparisons indicate the possibility of environmental harm.
The assessment of environmental risk is generally more complex than a
human health evaluation. This additional complexity occurs because the
"environment" consists of an assembly of species of plants, animals and
microbes as opposed to the single species considered in a human health
evaluation. In addition, all of these species have some degree of interaction
with many others in the community and with the physical/chemical
characteristics of the abiotic environment. At the same time, the endpoint of
concern in an environmental evaluation is population maintenance, not
individual health as in an evaluation of human health effects.
Species interactions and differences in the endpoints of concern tend" to
limit the amount of available information which is useful for estimation of
IJ The list of indicator chemicals include the background chemicals
evaluated in Chapter 4.
-------
OSWER Directive -9483.00-2
7-2
environmental impact. As a result, toxicity data for "environmental" species
are generally less abundant than for humans. For example, it is not possible
to derive toxicity constants for individual chemicals as was done for the
human health evaluation. This lack of data requires many simplifying
assumptions to complete the evaluation. Extensive extrapolations from
chemical analogs or laboratory bioassay data do not accurately reflect
chemical impacts at the ecosystem level. However, these data are often the
only information available, and, consequently, a large degree of uncertainty
results. Thus, many parameters must be ignored or estimated using
conservative assumptions, especially when endangered species or unique
habitats are considered.
This environmental impact evaluation compares exposure"point
concentrations in surface water and ground water estimated in Chapter 5 to
quality criteria for water2-1 . However, no comparable set of quality
criteria for environmental exposure to soil- or sediment-bound chemicals are
available. Thus, if these routes of exposure are thought to be important,
either a site-specific conversion factor or experimental data may be required
to complete the evaluation. Likewise, the degree of projected damage to
physical structures will have to be estimated based upon existing corrosion
resistence data for the affected structure.
Carcinogenic effects are not considered in the environmental impact
evaluation. In the absence of data to the contrary, carcinogens potent enough
to result in population perturbations in the ecosystem are assumed to be
adequately addressed at lower levels in the human health evaluation.
Distinctions between toxicological effects of different chemicals are
generally not possible. Therefore, any observed effect which may reduce the
lifespan or reproductive potential of an organism or population is considered
a hazardous effect.
The basic process of the environmental impact evaluation is illustrated in
Exhibit 7-1. In general, potential hazards to the environment are assessed by
comparing exposure point concentrations to established standards or guide-
lines. A field evaluation may be useful to provide information concerning the
species present at exposure points, the population sizes, the presence of
endangered or threatened species, and the proximity to parkland or human-made
structures. This information can be used to determine the scope necessary for
the environmental evaluation.
The next step is to list the important chemicals and calculate exposure
point concentrations associated with each chemical (see Chapter 5). Note that
this list may be a more extensive list of chemicals than that used in the
health evaluation described in Chapter 6. The calculations of exposure point
concentrations for any chemicals not included in the list of indicator
chemicals evaluated in Chapter 6 are based on methods presented' in Chapter 5.
These calculated values of exposure point concentrations are then compared
with quality criteria previously established by EPA. If site-specific
conditions warrant, alternative methods of deriving appropriate criteria values
Ij EPA, Quality Criteria for Water, Office of Water Regulations and
Standards, 440/5-86-001, 1986.
-------
OSWER Directive 9483.00-2
Exhibit 7-1
OVERVIEW OF ENVIRONMENTAL IMPACT EVALUATION
Identify exposure point concentrations
(from Chapter 5).
SECTION 7.1
Do
relevant
quality criteria
exist for all
chemicals?
No
SECTION 7.2
Calculate exposure
point concentration:
quality criteria ratios.
Derive site-specific
quality values.
Sum ratios for
indicator chemicals for
each exposure point.
Do
ratios
indicate potenual
ecological
damage?
Environmental impact
evaluation complete.
SECTION 7.3
Conduct environmental
site evaluation.
-------
OSWER Directive-9483.Op-2
7-4
are used as presented in Section 7.2. Site-specific adjustment-of criteria
may be needed because a species at a site is more or less sensitive than those
used to determine the national criteria value. Physical and chemical
characteristics of the site may ameliorate or enhance the biological
availability and/or toxicity of chemicals and could warrant the development of
site-specific criteria. In some situations, water quality criteria will not
be available for all indicator chemicals and the development of site-specific
criteria will be necessary to perform the evaluation. In the event that the
evaluation indicates potential environmental harm, Section 7.3 presents
guidance on the types of information which will be needed for a risk-based
variance. " __
7.1 COMPARE EXPOSURE POINT CONCENTRATIONS AND QUALITY STANDARDS
The first step in the evaluation of environmental risk, the determination
of environmental receptor.exposure point concentrations, has been performed in
Chapter 5. After the exposure point concentrations have been determined,
projected concentrations are compared to EPA's water quality criteria.5-1
Consideration of the assumptions made to derive the water quality criteria
should be made in order to determine if they are relevant to use for
comparison. Water quality criteria were developed to be relevant and useful
for most situations. However, unusual differences in species sensitivity or
site chemistry may warrant development of site-specific criteria for some
sites. Marine criteria are for applications in which exposure occurs in salt
water.
For each environmental exposure point, list the chemicals and projected
concentrations on Worksheet 7-1. Exposure point concentrations can be
obtained from Worksheet 5-4. Refer to Exhibit 7-2 and record each chemical's
chronic quality criteria. Water quality criteria are available for only a
limited number of chemicals. However, lowest observed effect levels (LOELs)
are available for a substantially larger number of chemicals. These
concentrations are also listed on Exhibit 7-2 and marked by an asterisk. If a
criterion is not listed, use either the chronic LOEL divided by 10 or the
acute LOEL divided by 100, whichever is lowest. These divisors are derived
from currently available data on the toxicity and ecological effects of
chemicals released in the environment, and they take into account the
uncertainties due to such variables as test species sensitivity, laboratory
test conditions and age-group susceptibility. A support document containing a
detailed discussions of the derivation of the values is available from EPA's
Office of Toxic Substances."-1
J-i EPA, Quality Criteria for Water, Office of the Water Regulations and
Standards, 440/5-86-001, 19S6.
UJ EPA, Estimating "Concern Levels" for Concentrations of Chemical
Substances in the Environment (unpublished), available from Office of Toxic
Substances, Health and Environmental Review Division, Environmental Effects
Branch, 1984.
-------
WORKSHEET 7-1
COMPARISON 01 I NVIKONHf NIAl RECEPTOR EXPOSURE I'OINT CONCENTRAI I ON
Wl III WATER QUALITY CRITERIA
INSTRUCTIONS:
1. List all chemicals for the exposure point.
2. List projected total exposure point concentration
from Worksheet 5-^. Indicate whether short-term or long-term concentration.
3. list type (e.g., criteria, LOEL) and value of relevant water
quality criteria for each chemical.
it. Divide projected exposure concentration by criteria concentration.
5. Sum the ratios Tor all chemicals at the exposure point.
faciIi ty ID:
Cluster/lank System:
Date:
Analyst:
Qua Ii ty Control:
Exp
1 .
2.
3.
losure Point:
Chemica 1
Arsenic! tri )
Cadmium
Lead
1 ron
Sprinq
Exposure Point
Concentration
(mg/l)
0,005 mq/l
0.005 mq/l
0,001 mq/l
0.250 mq/l
Type of Criteria
1 rush Chronic
fresh Chronic
Eresh Chronic
LOll/lO
Concentration (circle one): Short-term Long term
Qua I i ty Cr i teria
Va 1 uc Rn t i o
(n>9/D
0. 190 mq/l
0.0011 mq/l
0,0032 mq/l
0, 1 mq/l
0.026
'1.51)5
0.313
2.500
Total: 7.38'i
-------
EXHIBIT 7-2
a/
ACU1E AND CHRONIC UAIER QUALITY CRITERIA TOR PROTECTION
OF IKISHWATER AND MARINE ORGANISMS AND
I Of I (LOWEST OBSEIiVEO EFFECT LEVEL) VALUES b/
AcenapLhene
Ac ro 1 c i n
Acryloni tri le
Aldrin
Alkal inl ty
Ammonia ( Tola 1 )
Ammonia (Un- ionized)
Ant imony
Arsenic(pont )
Arsenicf tri )
Benzene
Denzidine
Be ry 1 1 i urn
BIIC
Cadi urn
Carbon Tetrachloride
Chlorakyl ethers
Chlordane
Chlorinated Benzenes
Chlorinated Napthiha lenes
Chlorinated Phenols
Chlorine
Chloro i| Methyl-3-Phenol
Chloroform
Chlorophenol
Chlorophenol 2
Chlorophenol <4
Chromfum( Ilex)
Chromiuroj Tri )
Copper
Cyanide
DDE
DDT
Demeton
Dichloroethane
D i ch 1 orobenzenes
D i ch 1 o roe thy 1 ones
Ui Chlorophenol 2,
-------
EXIIIHIT 7-2
a/
ACU1E AND CIIHONIC WAUR QUAl I IY CRITERIA TOR PROTECTION
01 IIUSIIWAIIR AND MARINE ORGANISMS AND
I 01 I (IOWISI OUSERVfO EFEECT LEVEL) VAIUES b/
Concentrations in uq/l
0 ichloropropcne
Uicldrin
Oimclhyl Phenol 2.M
Uini troiulucno
Oioxin(2.3.7.8-TCDO)
U i phony I hd raz i ne
Dissolved Oxygen
Endosul fan
Endrin
Eihy (benzene
E 1 no rant lie ne
Cull) ion
lla loethers
Ha lorne thanes
lleptnchlor
lloxaclilorobutad icne
llexach lorocyc lohexane ( Linda ne )
llexach lorocyc (open lad icne
llexach lo roe thane
1 ron
1 sophorone
1 ead
Ma lath ion
Mercury
Methoxychlor
Mi rex
Naphtha lene
Nickel
Ni trobenzene
Ni trophcnol s
Ni irosamines
Para th ion
PCD's
Pentachlorinated Ethanes
Pcntach lo ropheno I
pll
Phenol
Phosphorus Elemental
Phthalate Esters
1 roi.li Acni c
Cri tuna; I Ol L b/
6,06(1"
2.5
V. 120"
330"
0.01"
2/11"
6, 5O»
0.22
0. 16
32,000"
3,900"
360"
1 1 ,000"
0.52
90"
2.0
/"
980"
I 1 7,000"
82
2.U
2, 300"
1,800
2/.000"
230"
5,aI>o't
2.0
/,2'lO"
55"
1O,200»
9'lO"
( rcsh Chronic
Criteria; LOEl b/
2i|i|"
0.0019
230"
0.0056"
',000
0.006
0.0023
0.01"
122"
0.0038
9.3"
0.08
5.2"
5'iO"
1,000"
3.2
.01
0.012
0.03
0.001
620"
96
150"
O.Oii
0 . 0 1 l|
1. 100"
3.2"
6.5-9
2.560"
3"
Marine Acute
Criteria; LOEL
790"
0.71
590"
0.03'l
0.037
'i30"
lO"
12,000"
0.053
32"
0. 16
7"
' 9'iO«
12.900"
I'lO
2. 1
2.350"
I'lO
6.680"
M. 850"
3,300.000"
10
390"
53"
5.800"
2.9»i«4"
Marino Chronic
b/ Criicrni; LOEL b/
0.001 9
370"
0.0087
0.0023
16"
0.01"
6.»lOO»
O.0036
5.6
.01
0.025
0.03
0.001
7.1
O.Oil"
0.03
281"
3'l"
6.5-8.5
0. 1
3.»i"
-------
EXJIIllIT 7-2
a/
ACUIE AND CIIKONIC WAUR QUAI. I IY CRIUKIA I OR PROTECTION
Of IIUSMHAICH AND MARINE ORGANISMS AND
101 I (LOWLST OBSERVED EFFECT LEVEL) VALUES b/
Concenjra i joiis [n_ucj/J___
Fresh Chronic Marine Acute
Mesh Acme Fresh Chronic Marine Acute Marino Chronic
Criteria; IOEL b/ Criteria; LOEL b/ Criteria; LOEL b/ Criteria; LOEL b/
Polynuclear Aromatic
Hydrocarbons
Se lenium
Silver
Sul fide-Hydrogen Sulfide
Tetrachlorinated Ethanes
Tetrachloroethane 1,1,2,2
Tetrachlorocthylene
Tetrachlorophenol 2,3,4,6
Tha 1 1 Jura
lo lilt; no
loxaphene
Trichlor inated Ethanes
T r i ch 1 o roe t hy 1 ene
T richlorophenol 2. b. 6
Zinc
260
'i. 1
9, 120"
5,280"
I,I|OD"
17,500"
1.6
18,0011"
»l5.0Otl"
320
35
0. 12
2
2.1400
8i|0"
»lO»
0.013
21,900"
970"
»»7
300"
1*10
2.3
9,020"
10,200"
2-, 130"
6,300"
0.07
2.000
170
5'l
2
1(50"
»|I|0"
5.000"
58
a/ EPA has identified many chemicals (primarily metals) as having variable toxicity depending upon
water hardness. Applicants will need to consult the Quality Criteria Tor Water 1986 (EPA. 1986) to
identify which chemicals have variable toxicity and for the specific regression equations to
calculate quality criteria at ambient water hardness. The criteria presented in this exhibit are
based on a water hardness of 100 imj/l.
b/ LOEL values are reported when insufficient data exist
are denoted with an asterisk (*).
to calculate a water quality criterion and
-------
OSWER Directive 9483.00-2
7-9
For each chemical, divide the projected exposure point concentration by
the quality criterion to obtain a ratio of projected to protective
concentrations. If quality criteria are not available for one or more of the
chemicals, site-specific values must be derived as outlined in Section 7.2
before this worksheet can be completed. When all the criteria values have
been finalized, sum the ratios for all chemicals at each exposure point.
If the sum of the ratios is less than or equal to 1.0, there is a low
probability of environmental harm. A value between 1.0 and 10 is indicative
of possible harmful effects. A value greater than or equal to 10 is an
indication of probable environmental harm. This method -is similar to the
Office of Pesticide Programs' risk assessment method.SJ The main difference
between the two methods, however, is that in the Office of 'Pesticide Programs'
method, the effect level is related to a toxic concentration limit, while in
the environmental impact evaluation method of the risk-based variance, a lower
effect level (i.e., a less severe endpoint) is used for comparison (namely
quality criteria for protection of aquatic life).
At this point, an evaluation of the underlying assumptions may be
warranted. For example, if the most mobile indicator chemical is used to
represent all the indicator chemicals, a question to ask is whether the
transport rate of the most mobile chemical is radically different from the
other chemicals. If this is the case, the sum of the ratios may- be
artificially high. Conversely, this analytical method does not take into
account the possible impact of synergistic enhancement or antagonistic
reduction of toxicity by a mixture of chemicals. The approach assumes that
multiple subthreshold exposures result in adverse effects at a magnitude
proportional to the sura of the ratios of expected exposures versus acceptable
exposures.
A complete summary of levels of uncertainty, assumptions and
extrapolations should be included. Also, this summary should include a
discussion of the health of the ecosystem at the points of exposure. The
health of an ecosystem can be discussed in terms of stressed communities,
population diversity, important functional parameters of the community,
productivity, and stability. This information may be generated from site
surveys or from private, state, or federal information sources.
Human-made structures may also be affected from contamination with
hazardous waste. Potential contamination of physical structures is evaluated
by comparing estimated exposure point concentrations at the structure to the
corrosion resistance of the structural materials8-1 7J to individual
Sj EPA, Hazard Evaluation Division Standard Evaluation Procedure -
Ecological Risk Assessment, Office of Pesticide Programs, 540/9-85-001, 1986.
*J National Association of Corrosion Engineers, Corrosion Data Survey -
Nonmetals Section, (Houston: National Association of Corrosion Engineers,
1975).
7J National Association of Corrosion Engineers, Corrosion Data Survey -
Metals Section, (Houston: National Association of Corrosion Engineers, 1985).
-------
OSWER Directive 9483.00-2
7-10
contaminants. If concentrations of hazardous waste constituents exceed the
level that would ensure corrosion resistance of the structural material to a
specific chemical, deterioration of the structure may be of concern.
7.2 DERIVATION OF SITE-SPECIFIC CRITERIA
The purpose of this section is to provide guidance to applicants who need
to use alternate criteria for calculating concentration ratios because
available criteria either do not address or are not relevant for chemicals or
conditions at the site. The values derived in this section may be used where
local conditions warrant an adjustment (up or down) in existing criteria.
When a criterion does not exist for a chemical, provide the concentrations
estimated in Chapter 5 and any available toxicity information.
The EPA derives criteria for water quality by the complex manipulation of
a toxicity data base for aquatic organisms which is referred to as 'the
national acute toxicity data set. The data set contains verified toxicity
concentrations for the organisms listed in Exhibit 7-3. For both fresh and
saltwater environments, acute toxicity data for eight families of organisms,
acute-chronic ratios for three families, acute toxicity to an algal species or
vascular plant species and a measurement of bioconcentration are required to
calculate the water quality criteria.
Site-specific criteria development may be justified because species at a
given site may be more or less sensitive than those represented in the
national criteria document.lj For example, the national criteria data set
contains data for trout, salmon, penaeid shrimp, and other aquatic species
that have been shown to be especially sensitive to some chemicals. Because
these or other sensitive species may not occur at a particular site, they may
not be representative of those species that do occur there. Conversely, a
site may have untested sensitive species that are ecologically important and
need to be protected.
In addition, differences in physical and chemical characteristics of the
site have been demonstrated to ameliorate or enhance the biological
availability and/or toxicity of chemicals. For example, alkalinity, hardness,
pH, suspended solids and salinity influence the concentration^) of the toxic
form(s) of some heavy metals, ammonia, and other chemicals.
7.2.1 Derivation of Aquatic Criteria
EPA recognizes three methods for calculating site-specific water quality
criteria'-1 depending on why the site-specific criteria are needed for the
site. These methods are as follows: 1) recalculation procedure, which is
used if the species used to determine the toxicity data on which the water
quality critera are based are not relevant to the site; 2) indicator species
*J EPA, Quality Criteria for Water 1986, Office of Water Regulations
and Standards, 440/5-86-001, 1986.
SJ EPA, Waste Qualty Standards Handbook, Office of Water Regulations
and Standards, 1983.
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OSVER Directive 9483.00-2
7-11
EXHIBIT 7-3
CHEMICAL SPECIFIC TOXICITY INFORMATION IN THE
NATIONAL ACUTE TOXICITY DATA SET
I. Fresh Water
Acute toxicity
concentrations for
a Salraonid (trout or salmon)
a warmwater commercial or- recreational fish
(bluegill, catfish)
a third fish species or amphibian
a planktonic crustacean (cladoceran, copepod)
a benthic crustacean (ostracod, isopod,
crayfish)
an insect
a species which is not an arthropod or
vertebrate (molluscs, rotifers, annelids)
a family in any order of insect or phylum not
already represented
at least one fish species
at least an invertebrate species
at least one acutely sensitive species
a freshwater algal species or vascular plant
(if plants are among the aquatic organisms
that are most sensitive to the material,
results of a test with a plant in another
division is also required)
Bioconcentration factor - for at least one appropriate species
II. Salt Water
Acute-chronic ratios for -
Acute toxicity
concentrations for
Acute toxicity
concentrations for
Acute-chronic ratios for -
two vertebrate families
any crustacean in the Mysid or Penaeid family
three other non-vertebrate families
a species which is not a vertebrate or anthropod
any family not already used
a fish species
an invertebrate species
an acutely sensitive saltwater species
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7-12
EXHIBIT 7-3 (Continued)
CHEMICAL SPECIFIC TOXICITY INFORMATION IN THE
NATIONAL ACUTE TOXICITY DATA SET
Acute toxicity
concentrations for - a saltwater algal species or vascular plant
(if plants are among the aquatic organisms that
are most sensitive to the material, results of
a test with a plant in another division is also
required)
Bioconcentration factor - for at least one appropriate species
III. Other Information
Information on dependence of toxicity of the chemical on environmental
factors (e.g., water hardness and metals)
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7-13
procedure, which is used to adjust for differences in water quality that may
affect the toxicity and biological availability of hazardous waste at the
site; and 3) resident species procedure, which is used to concurrently adjust
for species sensitivity and aquatic chemistry effects that may simultaneously
occur necessitating criteria adjustment. Details of the three procedures are
given in the above reference. These procedures range from relatively simple
and straightforward to quite complex laboratory analyses. Professionals
trained in aquatic toxicology may be required to perform some of these tests
and interpret che results. A brief discussion of the conditions under which
these procedures may be used are outlined below to give _the applicant an
overview of the subject.
Recalculation Procedure
The recalculation procedure allows modifications in the national acute
toxicity data set by eliminating data for species that are not resident at the
site.'. This procedure is designed to compensate'for any real difference
between the sensitivity range of species represented in the national data set
and species found at a site. Sufficient toxicity data may be available for
other, more relevant species, allowing simple recalculation with the relevant
toxicity data. However, elimination of data for this recalculation procedure
may result in insufficient data to meet the national minimum data set
requirements, in which case additional resident species acute testing in
laboratory water is required before this procedure can be used.
Certain families or organisms have been specified to be represented in the
National Guidelinesl°J acute toxicity minimum data set (e.g., Salmoidae in
freshwater and Penaeidae or Mys'idae in saltwater). All specified families may
not exist at any given site. If this or any other requirement cannot be met
because the family or other group (e.g., insect or benthic crustacean in
freshwater) is not represented by resident species, select a substitute(s)
from a sensitive family represented by one or more resident species to meet
the eight family minimum data set requirement. If all the families at the
site have been tested 'and che minimum data set requirements have been met, use
the most sensitive resident family mean acute value as the site-specific Final
Acute Value (FAV), which is defined as an estimate of the chemical
concentration that is not acutely toxic to 95 percent of the species present
at the site. No chronic testing is required by this procedure since the
acute/chronic ratio will be used with the site-specific FAV to obtain the
site-specific Final Chronic Value (FCV). The acute/chronic ratio is the
quotient of the mean acute toxicity concentration divided by the mean chronic
toxicity concentration for the chemical. Therefore, the site-specific FCV is
the ratio of the site-specific FAV to the acute/chronic ratio.
In addition to toxicity values, Final Residual Values (FRV) may also be
calculated for areas where the occurrence of elevated contaminants in the
flesh of commercially or environmentally important species is possible. For
lipid soluble chemicals whose FRVs are based on Food and Drug Administration
(FDA) action levels, adjustments in these values based on the percent lipid
IOJ EPA, Quality Criteria for Water 1986, Office of Water Regulations
and Standards, 440/5-86-001, 1986.
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Uirective y4<3J. 00-2
7-14
content of resident aquatic species is appropriate for the derivation of
site-specific FRVs. For lipid soluble chemicals, the national FRV is based on
an average 11 percent lipid content for edible portions for the freshwater
chinook salmon and lake trout and an average of 10 percent lipids for the
edible portion for saltwater Atlantic herring. An adjustment for these
differences may be necessary, because resident species of concern at any given
site may have higher (e.g., Lake Superior siscowet, a race of lake trout) or
lower (e.g., many sport fish) percent lipid content than those species used
for the national FRV.
For some lipid soluble chemicals such as polychloriaated biphenyls (PCB)
and DDT, the national FRV is based on wildlife consumers of fish and aquatic
invertebrate species rather than an FDA action level because the former
provides a more stringent residue level1 IJ. Since the data base on the
effects of ingested aquatic organisms on wildlife species is extremely
limited, it would be inappropriate to base a site-specific FRV on resident
wildlife species. Consequently, site'specific modifications for these
chemicals are based on percent lipid content of resident species consumed by
humans.
For the lipid soluble chemicals whose national FRVs are based on wildlife
effects, the limiting wildlife species (mink for PCB and brown pelican for
DDT) are considered acceptable surrogates for resident avian and mammalian
species (e.g., herons, gulls, terns, otter) and a less restrictive
modification of the national FRV is not appropriate. The site-specific FRV
would be the same as the national value.
Indicator Species Procedure
This procedure is based on the assumption that physical and/or chemical
characteristics of water at an exposure site influences biological
availability and/or toxicity of a chemical. This procedure is designed to
compensate for site water quality characteristics which may affect the
biological availability and/or toxicity of a chemical. Major factors
affecting aquatic toxicity values of many chemicals, especially heavy metals,
have been identified. For example, the carbonate system of natural waters
(pH, hardness, alkalinity, and carbon dioxide relationships) has been the most
studied and quantified with respect to effects on heavy metal biological
availability and/or toxicity to aquatic life.
Acute toxicity in site water and laboratory water is determined using
representative species resident at the site, or acceptable non-resident
species as indicators or surrogates for species found at the site. The
difference between toxicity values determined for the site water and for the
laboratory water on which the national criteria were based, expressed as a
water effect ratio, is used to convert the national maximum concentration for
a chemical to a site-specific maximum concentration from which a site-specific
Final Acute Value (FAV) is derived.
1IJ EPA, Quality Criteria for Water 1986, Office of Water Regulations
and Standards, 440/5-86-001, 1986.
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This procedure also provides three methods for obtaining a site-specific
Final Chronic Value (FCV). One method consists of calculating the FCV (no
testing required) if a Final Acute/Chronic Ratio for a given chemical is
available in the national criteria document.11-1 This ratio is simply
divided into the site-specific FAV to obtain the site-specific FCV. The
second consists of obtaining the FCV by performing at least two acute and
chronic toxicity tests on both fish and invertebrate species (resident or
non-resident) in site water. Acute/chronic ratios are calculated for each
species, and the geometric mean of these ratios are then divided into the
site-specific FAV to obtain the site-specific FCV. The -third method consists
of obtaining an FCV by performing chronic toxicity tests- with at least one
fish and one invertebrate (resident or non-resident) in both laboratory water
and site water and calculating a geometric mean chronic water effect ratio
which is used to modify the national FCV.
Resident Species Procedure
This procedure is designed to compensate concurrently for any real
differences between the sensitivity range of species represented in the
national data set and for site water conditions that may markedly affect the
biological availability and/or toxicity of the material of interest. The
purpose is to develop the complete acute toxicity minimum data set using site
water and resident species. Derivation of the site-specific maximum and
chronic concentration would be accomplished after conducting tests with a
sufficient number of resident species in site water. Sufficient species must
be tested to satisfy acute toxicity minimum data set requirements. Chronic
tests may also be necessary to derive site-specific acute-chronic ratios.
7.2.2 Derivation of Terrestrial Criteria
The evaluation of effects of released chemicals on terrestrial biota is
considerably more complex than for aquatic biota. Data on the routes of
exposure and chemical transfer between organisms via the food web are very
limited. Mammals, birds, and crop plants are given more emphasis in this
regard than the other terrestrial species because there are established
protocols for testing these species and they have a greater direct economic
value than other types of organisms. This emphasis does not necessarily
indicate, however, that they are the most important or the best indicators of
environmental quality. As with site-specific water quality criteria,
terrestrial values may be derived from scientific literature values or
laboratory or field data. For mammalian values, data from mammalian (rat)
toxicity studies for use in human health evaluations may be used in addition
to wild mammal toxicity studies or field studies. Protocols for toxicity
testing are specified by EPA in 40 CFR Parts 796, 797, and 798. For the
purpose of animal environmental evaluations, only oral or dermal routes of
exposure are usually considered relevant.
IJJ EPA, Quality Criteria for Water 1986, Office of Water Regulations
and Standards, 1986.
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Exposure to hazardous substances may come partly from surface water,
partly from contaminated plants, and partly from contaminated prey (in the
case of predators). Methodologies for establishing dose levels for
terrestrial animals have been detailed by the Office of Pesticide
Programs.lJJ The methods require a series of data inputs and conversions to
derive a concentration level. LD.Q (lethal dose to 50 percent of test
organisms) data are converted to LD-.s relative to animal body weight. The
quantity of toxicant available to the organism is generated using exposure
route information from Chapter 5, and estimates in intak.e/exposure are
developed based on site-specific information concerning-relevant species and
exposure scenarios. The mass of toxicant actually ingested must be estimated
either from extrapolations of laboratory data on indicator species, on
resident species, or from actual field studies. These values will vary
tremendously with the species tested. For terrestrial plants, dose is
relatively straightforward. The.environmental receptor exposure point
concentration in the ground water or soil is quantified in Chapter 5 and this
level is compared to toxic levels (similar to the methods for aquatic
organisms). However, few data are available on the toxicity of RCRA hazardous
substances to terrestrial vegetation. Thus, measurements will be required or
the uncertainties associated with a qualitative assessment must be acceptable.
For environmental impact evaluations, a range of organisms (mammal, bird,
vascular plant) and a range of sensitivity must be included. The objective of
the study is to obtain "no observed effect levels'1 (NOELs), or an exposure
concentration at which no effect on the organism is observed. The NOEL is
distinct from the the "no observed adverse effect level" (NOAEL). In the'
latter case, effects are observed due to exposure, but they are not considered
adverse for the test species.
A safety factor of either 100 or 10 is applied to the lowest NOEL. If
available data are for acute toxicity tests, divide the NOEL by 100. If the
available data are for chronic toxicity, divide the NOEL by 10. If an
endangered species has been identified as utilizing the potentially
contaminated environment, apply an additional safety factor of 10 to the
data. Use the resultant values to calculate the ratio between exposure point
concentration and criteria levels for each exposure point and chemical.
7.3 SITE-SPECIFIC EXPOSURE POINT EVALUATION
In the event that chemical concentrations are projected to be above the
water quality criteria as determined in Section 7.1 or site-specific criteria
as determined in Section 7.2, a variance permit may still be sought. However,
field evaluation of each exposure point where chemical concentrations indicate
the possibility of environmental harm will be necessary. The field evaluation
will include, but may not be limited to, compilation of species lists (plant
and animal), population estimates and diversity indices, population trends for
dominant species, projected impacts of the chemicals on population trends,
13J EPA, Hazard Evaluation Division Standard Evaluation Procedures -
Ecological Risk Assessment, Office of Pesticide Programs, 540/9-85-001, 1986.
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OSWER Directive 9483.00-2
7-17
presence of endangered or threatened species, proximity to protected habitats
or parkland, recreational use of the area, agricultural or other commercial
use of the area, and proximity to buildings, historical sites, utility
conveyances or other man-made structures. The species considered must include
both permanent residents and migrating species which may utilize the habitat
for only part of the year. Some of this information will already have been
generated in Chapters 4 and 5 and Section 7.1.
Surveys for compiling species lists are straightforward and standard
methods exist. The level-of-detail of the environmental survey will depend on
site-specific needs. Local educational institutions or"a state agency may
already, have the necessary information. The local office of the Fish and
Wildlife Service, U.S. Department of Interior, will be ablfe to provide lists
of endangered or threatened species, habitats and parklands. Local Chamber of
Commerce offices or the appropriate state agency may provide information on
agricultural production and value and information on utilities and
archeological or historical sites and their nature.
The most difficult aspect of the evaluation will be projecting the impacts
on population trends for the operating life of the tank system or beyond,
depending upon environmental transport rates. Note that the impacts must be
projected based upon present environmental conditions. This evaluation will
likely be qualitative because adequate quantitative data are not likely to be
available. If the exposure site is already chemically degraded or otherwise
stressed, the impact of additional chemical insult must be determined.
. Factors to take into consideration may include community stability and
productivity, impacts of released chemicals on functional parameters (e.g.,
nutrient cycling, community respiration, reproductive capacity, and carrying
capacity), bioaccumulation and food web transfers, and predator-prey
relations. Investigation of all of these factors will require the input
and/or active participation of knowledgeable professionals in the field (e.g.,
an ecologist). Field studies of actual community response to chemical
exposures may be necessary at some sites. The overriding principle in any
field survey, microcosom or field exposure study is to target the most
sensitive parameter in the impacted ecosystem.
Environmental impact evaluations can be complex assessments given the
variation in number and types of species possible at a site. These
calculations should address the limits of uncertainty in any of the
measurements and criteria being used and should include an assessment of the
assumptions, extrapolations, and data gaps which are inherent in any such
study. Exposure point concentrations, chemical intakes, and toxicity and
criteria data are all potential sources of uncertainty. On the other hand,
most environmental evaluations will not require elaborate scientific
procedures or development of specific criteria. Professional judgment is,
nevertheless, required in interpreting results of this evaluation to ensure
that relevant species are covered and proper criteria have been used. The
conclusions of the reports must satisfy the Regional Administrator that the
studies are valid, address the proper parameters, and clearly demonstrate a
lack of substantial environmental risk posed by the release scenario.
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OSWER Directive 9483.00-2
CHAPTER 8
SUMMARIZING THE RISK-BASED VARIANCE APPLICATION
At this point in the risk-based variance application process, the
following analyses have been completed:
a health effects evaluation; and
an environmental impact evaluation.
This chapter provides guidance for summarizing the results" of these
evaluations. In general, the summary must provide the following: (1) a
rationale for the level of detail of the analysis; (2) a description of each
of the steps discussed in Chapters 2 through 7 that were used in the analysis;
(3) the worksheets (or their equivalent) listed in Exhibit 8-1; (4) a
discussion of all the major sources of uncertainty in the data and estimates
(e.g., assumptions, data gaps, model uncertainties, sample variations,
detection limits); and (5) a conclusion.
As with the narrative component of the main text of the application, the
narrative component of the summary also plays a very important role. It
should briefly, but clearly, explain the methods used to generate the data in
the application. Recognizing that some reports or portions of reports may be
reviewed by the public, and especially by members of the potentially exposed
population, care must be taken to summarize the major steps and results of the
application in terms that are easily understood.
The following sections briefly describe the major topics that need to be
addressed in the summary of the application. Section 8.1 provides guidance on
summarizing the source, surrounding area, and exposure characteristics
addressed by Chapters 2, 3, 4, and 5. Section 8.2 pertains to Chapter 6
(Health Effects Evaluation), and Section 8.3 addresses Chapter 7
(Environmental Impact Evaluation). The applicant must refer to the individual
chapters of this manual to obtain a more thorough discussion of the topics
that must be addressed.
8.1 SUMMARIZE THE SOURCE, SURROUNDING AREA, AND EXPOSURE
CHARACTERISTICS
This section provides guidance on summarizing Chapters 2, 3, 4 and 5.
First, provide a brief site description and include a map indicating the
location of the systems or components in the application. Discuss the notice
of intent to apply for a variance, and how the estimated timetable (Worksheet
1-1) corresponded with the actual application.
Using worksheets and text generated by Chapter 2, discuss the physical,
chemical, and toxicological properties of the waste constituents in the tank
systems or components. Note any highly mobile, persistent, or toxic
chemicals. Provide the rationale for the indicator chemicals selected.
Discuss each chemical not selected and the reasons for not selecting it.
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OSWER Directive 9483.00-2 . .
8-2
EXHIBIT 8-1
WORKSHEETS FOR SUMMARIZING
THE RISK-BASED VARIANCE APPLICATION
Worksheet
Title Number
Timetable for Demonstration of Risk-Based Variance from 1-1
Secondary Containment
Scoring for Indicator Chemical Selection: Overall Concentration, 2-4
Koc, and log Kow Values
Scoring for Indicator Chemical Selection for Human Health Effects 2-8
Evaluation: Evaluation of Exposure Factors and Final Chemical
Selection
Scoring for Indicator Chemical Selection fer Environmental Impact 2-9
Evaluation: Evaluation of Exposure Factors and Final Chemical
Selection
Release Volume Profiles Associated with Each Tank System 2-10
Measured Ground-Water Concentrations of Background Chemicals 4-2
Measured Surface Water Concentrations of Background Chemicals 4-6
Potential Human Exposure Pathways 5-1
Potential Environmental Receptor Exposure Pathways 5-2
Contaminant Concentrations at Human Exposure Points 5-3
Contaminant Concentrations at Environmental Receptor Exposure Points 5-4
Comparison of Human Exposure Point Concentrations to 6-1
Established Standards
Pathways Contributing to Total Exposure 6-12
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8-3
EXHIBIT 8-1 (continued)
WORKSHEETS FOR SUMMARIZING
THE RISK-BASED VARIANCE APPLICATION
Worksheet
Title . . Number
Total Subchronic Daily Intake (SDI) ' 6-13
Total Chronic Daily Intake (GDI) 6-14
Critical Toxicity Values _ ~~ 6-15
Calculation of Subchronic Hazard Index for Each Exposure Point . 6-16
Calculation of Chronic Hazard Index for Each Exposure Point 6-17
Calculation of Potential Carcinogenic Risks for Each Exposure Point 6-18
Comparison of Environmental Receptor Exposure Point Concentration 7-1
with Water Quality Criteria
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OSWER Directive 9483.00-2
8-4
Include a brief discussion of the indicator score rankings and other factors
used to determine the indicator chemical list. Referring to Worksheet 2-10,
discuss the worst-case release .volumes and release masses. Identify each tank
system component, and briefly describe the release volumes of each. Include
the rationale for the chosen release rates. Discuss each tank system's
minimum, maximum, and representative release mass profile.
Summarize information gathered from the hydrogeologic characterization of
the facility (Chapter 3), including climatic features, geology at and
surrounding the site, lithologic and hydrologic features of the unsaturated
and saturated zones, ground-water flow directions and rates, and surface water
features.
Discuss the surrounding land use, water use, and water quality of both
surface waters and ground water in the vicinity of the facility (Chapter 4).
Existing background levels of contamination for both surface waters and ground
waters should be discussed (Worksheets 4-2 and 4-6). If the facility has
experienced a prior release, special attention should be devoted to discussing
the effects of the release or releases on ground-water and surface water
quality. The applicant should also briefly describe other suspected release
sources in the area such as naturally occurring background chemicals, CERCLA
sites, other RCRA facilities, and wastewater dischargers; highlight any
significant adverse effects on water quality in the area that might be
attributable to these sources. Any ongoing remediation efforts in connection
with other release sources should also be discussed.
Drawing upon the appropriate worksheets and text generated by Chapter 5,
discuss the current and future potential human and environmental exposures
associated with the site. If it was determined that neither current nor
future potential exposures exist, and, therefore, that no substantial present
or potential hazards exist, then clearly summarize the determination of no
exposures. If current or future potential exposures do exist, then discuss
the highest current and/or future potential exposure. Also, note all other
potential exposures. Describe where the exposure points are in relation to
the site and how exposure might occur there. Discuss the release sources,
transport mechanisms, transport media, exposure routes, and exposed
populations. Note any sensitive subpopulations. Describe the fate and
transport models that were used to estimate the exposure point
concentrations. Provide the rationale for the models chosen and include a
brief discussion of the supporting documentation. Timing of exposures (i.e.,
short-term and long-term) must also be discussed.
8.2 SUMMARIZE THE HEALTH EFFECTS EVALUATION
The first major topic of the health effects evaluation (Chapter 6) is the
established quality standards relevant to the site (Worksheet 6-1). Note any
acceptable standards that are violated by the estimated chemical concentra-
tions; identify the chemicals involved, the standard and its numerical value,
and the numerical values of the lower, representative, and upper concentration
estimates. Discuss the standards determined to be most appropriate. Address
cumulative (i.e., additive) effects as depicted by the summed ratios of
estimated concentrations to acceptable standards and most appropriate
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. OSWER Directive 9483.00-2
8-5
standards. Note any summed ratios that exceed one. If an acceptable standard
exists for each indicator chemical, indicate this and omit the following'
summary discussion on intake estimation and noncarcinogenic and carcinogenic
risk characterization; proceed instead to the discussion on unquantified
health considerations.
Discuss the chemical intake estimates used in the risk characterization
(Worksheets 6-12, 6-13, and 6-1A.). Address the exposure routes, durations,
and amounts of intake. Present the total exposure scenarios for each exposure
point; include a summary of the relevant route-specific, estimated intake.s that
were combined to give total daily oral intake and total- daily inhalation
intake.
Chemical toxicity values used to characterize risk must be discussed
(Worksheet 6-15). If it was necessary to derive a value based on available
toxicological or epidemiological data, provide a brief description of the data
and the process used to develop the toxicity value. If a toxicity value was
needed but not derived, indicate the reasons for not doing so.
Summarize health risk due to noncarcinogens (Worksheet 6-16 and 6-17).
Discuss the lower, representative, and upper estimates of the subchronic and
chronic hazard indices calculated for all noncarcinogens for each total
exposure point; include each chemical's severity rating (.a qualitative scale
indicating the severity of the health endpoint; the severity rating scale is
given in Exhibit D-l). If an index exceeds one and was recalculated for each
health endpoint, summarize this information. Discuss the chemicals that
dominate the risks.
Information about carcinogenic risk must be summarized (Worksheet 6-18).
First, address the range of total carcinogenic risk at each total exposure
point. The weight-of-evidence rating, a qualitative scale based on the
amount, relevance, and quality of the toxicity data, must be included. This
value can be found in Appendix C. If possible, include some measure of che
reliability of the risk information (e.g., 95 percent confidence level,
standard deviation). At many sites, some chemicals will be responsible for
most of the risk at the site because of high toxicity, large projected
releases, or high concentrations. Discuss these especially important
chemicals here.
Describe the unquantified health considerations at this point. Address
any of the exposure pathways from Worksheet 5-1 that were not considered in
the comparisons to standards or the calculations of noncarcinogenic indices or
carcinogenic risks. Explain why it was not necessary to consider these
exposure pathways.
Sources of uncertainty, such as data gaps, incomplete toxicity informa-
tion, sample variation, and uncertainty contributed by modeling, and all
assumptions, must be discussed. If ranges of uncertainty or confidence levels
for particular circumstances are known, they must be included. Finally, any
comments that are necessary to explain assumptions, difficulties, results, or
conclusions relating to the assessment should be made at this point.
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8-6
8.3 SUMMARIZE THE ENVIRONMENTAL IMPACT ASSESSMENT
To facilitate presentation and review of the environmental impact
assessment, the applicant must first summarize and explain the basis for the
quality criteria used in the environmental assessment. When criteria
established by EPA (e.g., Exhibit 7-2) have been used, only the selection of
fresh water or salt water and chronic or acute values needs to be summarized.
When criteria have bocn derived from other published data or site-specific
measurements, a brief presentation of analytical methods and calculations is
necessary.
Summarize the ratios of exposure point concentration to ambient quality
criteria (Worksheet 7-1). In the event that the- overall sum of the
concentration/criteria ratios for an exposure point exceeds one, the variance
demonstration should include a presentation and discussion of any
concentration/criteria ratios calculated for each of the separate toxicity
mechanisms of concern.
8.4 CONCLUDE AND SUBMIT THE RISK-BASED VARIANCE APPLICATION
The demonstration of no substantial present or potential hazard to human
health and the environment should provide a conclusion by the applicant that
addresses the question of substantial present or potential hazard. It should
clearly state the rationale for the conclusions that are drawn. If any
concentration/standard ratio summations or noncarcinogenic hazard indices
exceed one, or if carcinogenic risk exceeds 10 , or if hazardous substances
for which criteria could not be derived are included in the variance
demonstration, the applicant must provide further explanation to demonstrate
that a risk-based variance is appropriate. The nature of the evidence required
for the risk-based demonstration in this case is primarily a function of
site-specific conditions, so detailed guidance on the material to be included
in the application is not presented here.
The applicant should be aware that even if concentration/standard ratio
summations and noncarcinogenic hazard indices are less than one, if
carcinogenic risk is less than 10 , and if all indicator chemicals have
toxicity values or standards, an application may still be inadequate in
demonstrating no substantial hazard. A demonstration may be inadequate for a
variety of reasons. For example, the applicant may have failed to choose
appropriate indicator chemicals, exposure pathways, or environmental fate and
transport models; or the uncertainty involved with modeling at a particular
site may be too high.
Finally, the narratives, worksheets, maps, and appendices generated as
described in this volume of the technical resource document, and any other
information deemed useful by the applicant, must be bound and delivered to the
appropriate U.S. EPA Regional Administrator no later than the statutory
deadline stated in the original notice of intent to apply. Failure to submit
a complete application by the deadline may result in denial of the
application, which Uill in turn result in a requirement that the applicant
install secondary containment for the hazardous waste tank systems or
components in question.
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OSWER Directive 9483.00-2
REFERENCES
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'68-03-3116.
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OSWER Directive 9483.00-2
-2-
Fetter, C.W. Jr., 1980. Applied Hydrogeology. Charles E. Merrill,
Columbus, Ohio.
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Foster, S.A. and Chrostowski, P.C., 1986. Integrated Household Exposure
Model for Use of Tap Water Contaminated with Volatile Organic Chemicals:
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Minneapo1 is, Minnesota.
Freeze, R. and Cherry, J., 1979. Groundwater. Prentice-Hall, Englewood
Cliffs, New Jersey.
GCA Corporation, 1982. Evaluation and Selection of Models for Estimating
Air Emissions from Hazardous Waste Treatment, Storage, and Disposal
Facilities. Prepared for U.S. Environmental Protection Agency, Office of
Solid Waste, Washington, D.C.
Grain, C.F., 1982. Vapor Pressure. Chapter 14 in Lyman et al., Handbook
of Chemical Property Estimation Methods, McGraw-Hill, New York.
Holzer, T.L., 1984. Ground Failure Induced by Ground-Water Withdrawal
from Unconsolidated Sediment. In: Man-Induced Land Subsidence, Volume VI of
Reviews in Engineering Geology. Geological Society of America, Boulder,
Colorado.
International Committee on Radiologic Protection (ICRP), 1975. Report of
the Task Group on Reference Man. Pergamon Press, New York.
Jaber, H.M., Mabey, W.R., Liu, A.T., Chow, T.W., Johnson, H.L., Mill, T.,
Podall, R.T., and Winterle, J.S., 1984. Data Acquisition for Environmental
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U.S. Environmental Protection Agency, Washington, D.C., EPA 600/6-84-009.
Kenaga, E.E. and Goring, C.A.I., 1978. Relationship Between Water
Solubility, Soil-Sorption, Octanol/Water Partitioning, and Bioconcentration of
Chemicals in Biota. In: Aquatic Toxicology, ASTM STP 707, J.G. Eaton, P.R.
Parris'h, and A.C. Hendricks, Eds. American Society for Testing and Materials,
Philadelphia, Pennsylvania.
Kimbrough, R.D., Falk, H., Stehr, P., and Fries, G., 1984. Health
implications of 2,3,7,8-tetrachlorodibenzodioxin (TCDD) contamination of
residential soil. J. Tox. Environ. Health 14:47-93.
Kruseman, G.P. and N.A. DeRidder, 1979. Analysis and Evaluation of
Pumping Test Data. International Institute for Land Reclamation and
Improvement Bulletin 11, Wageningen, The Netherlands.
Loucks, D., Stedinger, J., and Haith, D., 1981. Water Resource Systems
Planning and Analysis. Prentice-Hall, Englewood Cliffs, New Jersey.
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OSWER Directive 9483.00-2 <,
-3-
Lyman, W.J., Reehl, W.F., and Rosenblatt, D.H., 1982. Handbook of
Chemical Property Estimation Methods. McGraw-Hill, New York.
Lyman, W.J., 1982a. Solubility in Water. Chapter 2 in Lyman et al.,
Handbook of Chemical Property Estimation Methods, McGraw-Hill, New York.
Lyman, W.J., 19S2b. Adsorption Coefficient for Soils and Sediments.
Chapter 4 in Lyman et dl., Handbook of Chemical Property Estimation Methods,
McGraw-Hill, New York.
Mabey, W.R. , Smith, J.H. , Podoll, R.T., Johnson, H.-L. , Mill, T. , Chou,
T.W., Gates, J., Patridge, I.W., Jaber, H., and Vandenberg, D., 1982. Aquatic
Fate Process Data for Organic Priority Pollutants. Prepared by SRI
International, EPA Contract Nos. 68-01-3867 and 68-03-2981, prepared for
Monitoring and Data Support Division, Office of Water Regulations and
Standards, Washington, D.C.
Maki, A.W., Dickson, K.L., and Cairns, J., eds., 1980. Biotransforma-
tion and Fate of Chemicals in Aouatic Environments. American Society for
Microbiology, Washington, DC.
Menzer, R.E. and Nelson, J.O., 1980. Water and Soil Pollutants. Chapter
25 in Doull, J., Klaassen, C.D., and Aradur, M.D., Toxicology, MacMillan, New
York.
Mills, W..B., Dean, J.D., Porcella, D.B. et al., 1982. Water Quality
Assessment: A Screening Procedure for Toxic and Conventional Pollutants,
Parts One and Two. Office of Research and Development, U.S. Environmental
Protection Agency, Athens, Georgia. EPA 600/6-82-004 a and b.
Mullineaux, D.R., 1976. Preliminary Overview May of Volcanic Hazards in
the 48 Conterminous United States: U.S. Geological Survey. Miscellaneous
Field Studies Map MF-786, Scale 1:7,500,000.
National Academy of Sciences, 1977. Drinking Water and Health. NRC
Press, Washington, D.C.
National Association of Corrosion Engineers (NACE), 1975. Corrosion Data
Survey - Nonmetals Section. Houston, Texas.
National Association of Corrosion Engineers (NACE), 1985. Corrosion Data
Survey - Metals Section. Houston, Texas.
Nelson, D.W., Elrick, D.E., Tangi, K.K., Krai, D.M., and Hawkins, S.L.,
eds., 1983. Chemical Mobility and Reactivity in Soil Systems: Proceedings of
a symposium sponsored by the American Society of Argonomy and the Soil Science
Society of America. American Society of Agronomy, The Soil Science Society of
America, Madison, Wisconsin.
NIOSH, 1980. Registry of Toxic Effects of Chemical Substances. DHHS
Publication No. 80-111.
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OSWER Directive 9483.00-2
-4-
Rawls, W.J., Brakensiek, D.L., and Saxton, K.E. 1982. Estimation of Soil
Water Properties. American Society of Agricultural Engineers Trans.
25:1316-1320.
Reid, Robert C., Prausnitz, John M., and Sherwood, Thomas K., 1977. The
Properties of Gases and Liquids, 3rd ed. McGraw-Hill, New York.
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Detroit, Michigan.
Ruffner, J.A. and F.E. Blair, 1981. The Weather Almanac. Gale Research
Company, Detroit, MI.
Spangler, Merlin G. and Handy, R.L., 1982. Soil Engineering. Harper and
Row, New York.
Tafaak, H.H., Quave, S.A., Mastmi, C.I., and Barth, E.F., 1981. Biodegrad-
ability studies with organic priority pollutant compounds. J. Water Pollution
Control Fed. 53(10):1503-1518.
Turner, D.B., 1970. Workbook of Atmospheric Dispersion Estimates. AP-26,
U.S. Environmental Protection Agency, Office of Air Programs, Research
Triangle Park, North Carolina.
U.S. Environmental Protection Agency, 1986. Alternate Concentration Limit
Guidance Based on Section 264.94(b) Criteria, Part I: ACL Policy and
Information Requirements, Draft (December). Office of Solid Waste,
Washington, D.C.
U.S. Environmental Protection Agency, 1986. Criteria for Identifying
Areas of Vulnerable Hydrogeology Under RCRA: Statutory Interpretative
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Facilities. Office of Solid Waste and Emergency Response, Washington, D.C.
U.S. Environmental Protection Agency, 1986. Guidelines for Carcinogen
Risk Assessment. Federal Register 51:33992-34003.
U.S. Environmental Protection Agency, 1986. Guidelines for Exposure
Assessment. Federal Register 51:34042-34054.
U.S. Environmental Protection Agency, 1986. Guidelines for Ground-Water
Classification Under the EPA Ground-Water Protection Strategy, Final Draft
(December). Office of Ground-Water Protection, Washington, D.C.
U.S. Environmental Protection Agency, 1986. Guidelines for Mutagenicity
Risk Assessment. Federal Register 51:34006-34012.
U.S. Environmental Protection Agency, 1986. Guidelines for the Health
Assessment of Suspect Developmental Toxicants. Federal Register
51:34028-34040.
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OSWER Directive 9483.00-2 <.
-5-
U.S. Environmental Protection Agency, 1986. Guidelines for the Health
Risk Assessment of Chemical Mixtures. Federal Register 51:34014-34025.
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Standard Evaluation Procedure - Ecological Risk Assessment. Office of
Pesticide Programs, Washington D.C. EPA 540/9-85-001.
U.S. Environmental Protection Agency, 1986. Hazardous Waste Management
System; Standards for Hazardous Waste Storage and Treatment Tank Systems and
Generators; Final Rule and Advance Notice of Proposed Ruleraaking. Federal
Register 51:25422-25488.
U.S. Environmental Protection Agency, 1986. Quality Assurance Program
Plan for the Office of Solid Waste. Office of Solid Waste, Washington, D.C.
U.S. Environmental Protection Agency, 1986. Quality Criteria for Water.
Office of Water Regulations and Standards, Washington, D.C. 440/5-86-001.
U.S. Environmental Protection Agency, 1986. Superfund Exposure Assessment
Manual, Draft (January). Office of Emergency and Remedial Response,
Washington, D.C.
U.S. Environmental Protection Agency, 1986. Superfund Public Health
Evaluation Manual. Office of Emergency and Remedial Response, Washington,
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U.S. Environmental Protection Agency, 1985. Guidance on Feasibility
Studies Under CERCI^A. Office of Emergency and Remedial Response, Washington,
D.C.
U.S. Environmental Protection Agency, 1985. Guidance on Remedial
Investigations Under CERCLA. Office of Emergency and Remedial Response,
Washington, D.C.
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OSWER Directive 9483.00-2
-6-
U.S. Environmental Protection Agency, 1983. Water Quality Standards
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Walton, W.C., 1970. Ground-Water Resource Evaluation. McGraw-Hill
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Ear.thquake, Landslide, Expansive Soil Loss Models: J.H. Wiggins Company
Technical Report. Redondo Beach, California.
Zamuda, C.D., 1986. The Superfund Record of Decision Process: Part I--The
Role of Risk Assessment. ' Chemical Waste Litigation Reporter 11:847-859.
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OSWER Directive 9483.00-2
APPENDIX A
PRELIMINARY SCREENING FOR RISK-BASED VARIANCE
A:1 INTRODUCTION
A final rule was enacted July 14, 1986, for new and existing interim
status, permitted, and 90-day accumulation tank systems that substantially
amends pertinent sections of 40 CFR Parts 260, 261, 262, 264, 265, 270, and
271 (51 Federal Register 25422). One major feature of the rule is the
requirement for secondary containment with leak detection (hereafter simply
referred to as secondary containment) for most hazardous waste tank systems
(40 CFR 264.193 (51 Federal Register.25474)).^
The requirement for secondary containment may be waived in one of two
ways: (1) a technology-based variance involving the demonstration that
alternative design or operating practices will detect leaks and prevent the
migration of any hazardous waste beyond a zone of engineering control; or (2)
a risk-based variance involving the demonstration that if a release of
hazardous waste does occur, there will be no substantial present or potential
hazard to human health or the environment. The applicant for the risk-based
variance could demonstrate no hazard in one of two ways: (1) that no exposure
pathways exist; or (2) that potential exposure point concentrations do not
pose a hazard to human health and the environment. The second demonstration
involves using appropriate environmental fate and transport models, toxicity
characteristics of the waste, estimated exposures, and established
environmental quality standards.
The purpose of this appendix is to present a methodology that will help
the potential applicant decide whether to apply for a risk-based variance.
Potential applicants include owners/operators of interim status, permitted,
and 90-day accumulation hazardous waste tank systems who are required to
install secondary containment and are considering applying for a risk-based
variance. This appendix provides guidance on the use of a relatively simple
screening process using readily available information to assist the potential
applicant in deciding whether to apply for a variance or install secondary
containment. In addition to providing guidance, this screening procedure also
assists potential applicants in determining the level of detail that is likely
to be needed for the risk-based variance application. For example,
ground-water modeling may not be needed if it can be demonstrated that present
or potential exposure pathways do not exist.
The purpose of the screening procedure is to provide the applicant with a
quick and straightforward procedure for assessing whether to go forward with
the variance process. The screening process should take no more than eight
hours, although in situations where data must be collected from outside
sources it may take longer. It addresses some of the major issues affecting
IJ All references to regulations for owners and operators of permitted
hazardous waste facilities (40 CFR 264) also apply to interim status standards
for owners and operators of hazardous waste facilities (40 CFR 265).
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OSWER Directive 9483.00-2
A-2 .
a risk-based variance. The purpose of the screening process is to inform the
applicant of situations for which a variance from the secondary containment
requirement is not allowed, and of the types of issues and detailed data
gathering efforts that will need to be addressed in the actual variance
application. The preliminary screening also provides guidance to the
applicant on whether to continue with the screening process and variance
application.
It should be noted that professional judgment is needed for using and
interpreting this screening procedure. Although every effort has been made
in this screening procedure to recommend the appropriate course of action for
the potential applicant (i.e., when to apply for a variance and when to
install secondary containment), due to highly variable site-specific
conditions and constraints in the readily available information used in this
screening procedure, not all possible outcomes of a variance application are
foreseeable. Therefore, this screening procedure must be used with
caution. There will be some situations that at first appear to be less than
substantial hazards, only to become substantial after further analysis; the
reverse, of course, is also true. For example, as identified in the screening
questions of Section A.2, hazardous waste tanks located in areas where the
depth to ground water is greater than 50 feet are considered to pose a lower
hazard than those situated at shallower depths. The recent case of pesticide
contamination of the ground water in Hawaii at a depth of 800 feet2-1
demonstrates, however, that contamination of deep aquifers can occur in some
situations. Thus, although lack of shallow ground water at a site may
increase the likelihood that a variance is appropriate, it by no means ensures
that a variance 'application will be granted.
A.2 MAJOR ISSUES AFFECTING A RISK-BASED VARIANCE
The preliminary screening uses a question and answer format to assist the
potential applicant in deciding whether to apply for a risk-based variance
from the requirements for secondary containment of hazardous waste tank
systems. Worksheets are provided no assist the potential applicant in
summarizing all relevant information. This screening procedure will assist
the applicant in identifying:
Situations for which secondary containment is not required.
Consequently, an application for a variance is not needed.
Situations for which a variance is not allowed. Consequently,
the applicant should not proceed with the variance application.
Potential necessary future data gathering efforts. If
available information is limited, the applicant should
reconsider whether to pursue the variance process because
2J L.S. Lau and K.R. Green, Subsurface Water Quantity: Organic
Chemical Contamination of Oahu Groundwater. Special Report 7.0:85 prepared
by Water Research Center, University of Hawaii, for Hawaii State Legislature
and the Office of Environmental Quality Control, 1985.
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OSWER Directive 9483.00-2
A-3
extensive data gathering efforts may be necessary to support a
demonstration of no substantial hazard.
tfhether exposure pathways exist. If no exposure pathways
exist, then this approach will likely be used for the variance
demonstration. Otherwise, the demonstration will likely be
based on a demonstration of no hazard to human health and the
environment due to the chemical concentrations at exposure
points.
Section A.2.1 identifies tank systems and generators that are exempt from
the secondary containment requirement and tank systems that are ineligible for
a variance from the secondary containment requirement. Section A.2.2 provides
guidance on comparing chemical concentrations to established environmental
standards. Section A.2.3 identifies situations that are likely to pose more
of a hazard to human health and the environment than other situations. This
identification is based on surrounding hydrogeological, water use, and water
quality characteristics. The purposes of Sections A.2.2 and A.2.3 are to
provide the applicant with additional guidance on the types of information
that are likely to be required for the application. Section A.2.4 describes a
simple procedure to identify exposure pathways. Section A.2.5 provides
guidance on whether or not the applicant should continue with the screening
procedure and variance application process.
A.2.1 Regulatory Constraints
It is prudent to first determine whether secondary containment is even
required for the tank system or component of concern. Hazardous waste tank
systems used by generators of small quantities of waste, hazardous waste tank
systems that contain no free liquids and are situated inside a building with
an impermeable floor, and hazardous waste tank systems that serve as part of a
secondary containment system are currently exempt from the secondary contain-
ment requirement and, therefore, do not need a variance. Some guidance on
determining status is provided in Section A.2.1.1 below; other situations
exist, however, that allow regulatory exemptions from the secondary contain-
ment requirement. Those applicants unsure of their status concerning
secondary containment requirements are urged to examine the appropriate
sections of the regulations, or call the EPA RCRA/CERCLA Hotline at
(800) 434-9246 or, in Washington, D.C., at (202) 382-3000.
This section addresses conditionally exempt hazardous waste generators and
hazardous waste tanks (Section A.2.1.1) and situations that would definitely
result in no waiver from the secondary containment requirements due to
regulatory constraints. These situations involve new underground tank systems
or components (Section A.2.1.2), and time constraints resulting in a late
advance notice of intent to apply for a variance (Section A.2.1.4). Questions
for determining eligibility for exemptions and denial of applications can be
found in Worksheets A-l, A-2, and A-3. Following completion of the worksheets
the applicant will know whether further efforts toward obtaining a variance
are appropriate. All pertinent issues relating to regulatory constraints are
presented in the worksheets. Consequently, the applicant can identify whether
a variance is feasible without reading Sections A.2.1.1 through A.2.1.4.
These sections are provided for applicants who want additional details on the
particular issues.
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WORKSHEET A-l
JEST fOR APPI ICAIIIUIY Of THE SfCONOARY CONTAINMENT REQUIREMENT TO THE FACILITY
ICJi ONS:
1. Starting with the left-most column, determine which generator class
the faciIi ty is in.
2. Dot ermine which combination of accumulation LI inf.- anil amount stored
on site at one time matches the facility com) itinns.
3. Place a check in the right-hand column of the row that matches the
facility conditions. The column second fiom the right states whether
the facility is exempt from the secondary containment requirement.
NEXt STEPS:
If the facility is not exempt, continue wiih the screening process
(Worksheet A-2).
FaciIi ty ID:
Da to:
Analyst:
Qua Ii ty Control:
Quantity of Hazardous Waste Accuinul.it ion
Generated in a Calendar Month Time
< 100 kg
100-1000 kg
> 1000 kg
n. a.
< 100 days
> 180 days
n. a .
< 1BO days
> 160 days
n. a.
n.a.
Amount Stored On Site
At Any One Time
< 1000 kg
1000-6000 kg
> 1000 kg
> 6000 kg
< 6000 kg
n.a.
> 6000 kg
n.a.
Exempt/Not Exempt Check Applicable Category
exempt
exempt
not exempt
not exempt
exempt
not exempt
not exempt
not exempt
Note: If the facility is found to be exempt from the secondary containment requirement according to the table above, but
generates acute hazardous waste (as defined in <|0 Cfft 261.31. 261.32, and 261.33(o)) in excess of 1 kg in a calendar
month, or generates less than 1 kg of acute hazardous waste in a calendar month and more than 1 kg is stored on site at
one time for more than 180 days, the tanks storing acute hazardous waste are not exempt from the secqndnry containment
requirement. Generators who have questions as to the applicability of the secondary containment requirement to their tank
systems should call the EPA HCUA/CLKOIA Hotline at (800) M3'i~92M6. or. in Washington, O.C., at (202) 382-3000.
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WORKSITE I A-2
TEST fOR API'LICAOII IIY <)l Illl SECONUAKY CONIAINMENI REQUIREMENT AND ELICIOILITY
I OK A VARIANCE FOR INDIVIDUAL 1ANKS
INSTRUCTIONS:
1. lor each hazardous waste tank system or component for which a variance
Is being sought, respond yes or no to the iiuustions below.
2. Begin with question I and contine to the next recommended question.
NEXT STEPS;
1. IT the tank system or component is determined to be eligible to apply Tor a
variance (i.e., a variance is not forbidden mid itie tank system or component is not
exempt from secondary containment), cunt nine in Worksheet A-3 to determine the date
by which a notice of application Tor a variance must be submitted Tor the tank
system or component.
FaciIi ty ID:
Tank System:
Date:
Analyst:
Quality Control:
Quest ion
Response
(yes/no)
Next Step If Response Yes
Next Step IT Response No
1.
2.
3.
Does the tank system serve only as
part oT a secondary containment
system used to collect or contain
releases of hazardous waste?
Is the hazardous waste stored in
the tnnk absent of free liquids, as
demonstrated by EPA Method 9095?
Is the tank system
a buiIding wi th an
located inside
impermeable floor?
Does tank system ancillary equipment
include afooveground piping (exclusive
of flanges, joints, valves, and other
connections), welded flanges, welded
joints and welded connections that are
visually inspected daily, seal loss or
magnetic coupling pumps that are
visually inspected daily, or pressur-
i?ed aboveground piping systems with
automatic shut-off devices that are
visually inspected daily?
Exempt.
Continue to next question.
Exempt.
Ancillary equipment components'
identified are exempt from sec-
ondary containment. Continue to
next question.
Continue to next question.
Co to question 'I.
Continue to next question.
.Continue to next question.
-------
WORKSHLET A-2 (Continued)
1ESF IOR APPLICAUII I IV 01 lilt SECONDARY CONIAINMENI REQUIREMENT AND ELIGIBILITY
I OK A VARIANCE TOR INDIVIDUAL TANKS
Question
((espouse
(yes/no)
Next Step If Response Yes
Next Slop If Response No
5. Is the tank system or component new
(i.e., did construction begin after
July I'l, 1986) or has the tank system
been repaired after July l
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WORKSHEET A-J
DEADLINES fOK I'UOVIDING NOTICE Of INTENT TO APPLY FOR A VARIANCE a/
TaciIi ty ID:
lank System:
Rate:
An.i lys t:
Quality Control:
NEXT STEPS:
1. If the deadline can be met Tor providing notice of intent to apply Tor a variance, continue with the screening tool,
1. Hie following deadlines have been set Tor lank owners to provide to the
Regional Administrator written notice of intent to apply for a variance.
If these deadlines cannot be met. the variance application will be denied.
2. Clicck only one category that describes the li.i/.inlous waste tank in question.
Some categories may also require a dale to he written in that is determined
by the tank age.
Check Applicable
Category
Tank Description
Dead!ine
Tank used to store or treat a
waste that became hazardous after
January 12, 198?.
New tank (construction began after
July 1i|, 1966)
Existing tank (regardless of whether
the age of the tank system is known)
used to store or treat hazardous waste
identified by the following f I'A hazardous
waste numbers: (020, F021, 1022. 1026,
or F027.
For an existing tank system of known and documented age:
Tank system U or more years old as
of January 12, 1987.
Tank system less than 1J years old as
of January 12, 1987.
Replace January 12, 1987 in the below cutoff dates and age
categories with the date the waste was made ha/n rtlous, then
determine which category the tank falls under and write the deadline
date below.
Date:
30 days prior to entering a contract for installation.
January 12. 1987
January 12, 1987
Before the tank reaches 13 years in age.
Date:
For an existing tank system for which the age cannot be documented:
January 12, 1993 (6 years after January 12, 1987)
Facility less than 7 years old as
of January 12, 1987.
Facility between 7 and 13 years old
as of January 12, 1987.
Facility greater than 13 years old
as of January 12, 1987.
before the facility reaches l"3 years in age.
Date:
January 12, 1987
a/ Those deadlines am effective in unauthorised status. To the extent these deadlines are applicable wilder HSWA authorities.
they are also applicable in authorised states. '
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OSWER Directive 9483.00-2
A-8
A.2.1.1 Conditionally Exempt Hazardous Waste Generators and Hazardous
Waste Tanks
As discussed in the introduction, not all hazardous waste tank
owners/operators are required to install secondary containment. This section
will identify some situations where conditional exemptions exist. Worksheet
A-l addresses the types of exemptions that may apply to a whole facility.
Questions 1 through 4 in Worksheet A-2 are designed to test if individual tank
systems or components are exempt from the secondary containment requirement.
One exemption is for chose hazardous waste tank owners/operators who,
after determining their status based on all of the pertinent regulations,
conclude that they are generators of between 100 and 1000 k-g per month of
hazardous waste and that they accumulate this waste in tanks for less than 180
days (or 270 days if the generator must ship the waste greater than 200 miles)
and do not accumulate over 6,000 kg on-site at any time (40 CFR 265.201 (51
Federal Register 25485)). These generators are presently exempt from the
secondary containment requirement and, therefore, need not apply for a
variance.JJ Generators of less than 100 kilograms of hazardous waste in a
calendar month are also exempt from the secondary containment requirement (as
well as all other requirements), as long as they do not accumulate more than
1000 kilograms of hazardous waste on site at any one time (40 CFR 261.5).
Generators of acute hazardous waste, as listed in 40 CFR 261.31, 261.32,
and 261.33(e), are subject to different limits on their waste generation rates
and on-site accumulation in determining whether they are exempt from secondary
containment requirements. As long as no more than one kilogram of acute
hazardous waste is generated in a month and no more than one kilogram is
accumulated on site at any one time, the waste is not subject to secondary
containment requirements (or any other requirements) if it is stored in tanks
(40 CFR 261.5). Therefore, generators of acute hazardous waste who utilize
tank storage and meet these limitations do not need to apply for a variance
from the secondary containment requirement.
Another exemption from the secondary containment requirement is for tanks
that are used to store or treat hazardous waste that does not contain free
liquids and are situated inside a building with an impermeable floor (40 CFR
264.190 (51 Federal Register 25472)). To demonstrate the absence or presence
of free liquids in the stored/treated waste, EPA Method 9095 (Paint Filter
Liquids Test), as described in "Test Methods for Evaluating Solid Wastes,
Physical/Chemical Methods" (EPA Publication No. SW-846), must be used.
Tanks and sumps, as defined in 40 CFR 260.10 (51 Federal 'Register 25471),
that serve only as part of a secondary containment system to collect or
contain releases of hazardous wastes are also exempt from the secondary
containment requirement.
1J These generators should be aware, however, that EPA has proposed to
subject generators of 100 to 1000 kg/mo to the secondary containment
requirements (51 Federal Register 36342, October 9, 1986).
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OSWER Directive 9483.00-2
A-9
A.2.1.2 New Underground Tank System or Component
A new tank system is defined as a tank system that will be used for the
storage or treatment of hazardous waste and for which construction commences
after July 14, 19S6. A risk-based variance from secondary containment is not
allowed for new underground tank systems (40 CFR 264.l93(g) (51 Federal
Register 25473, July 14, 1986)). Questions 5 and 6 in Worksheet A-2 address
these types of tank systems.
A.2.1.3 Existing, Underground, Unfit-For-Use Tan-k System or Component
The definition of an unfit-for-use tank system or component is one from
which there has been a leak or spill (40 CFR 264.196 (51 Federal Register
25477)) or that has been determined through an integrity assessment or other
inspection to be no longer capable of storing or treating hazardous waste
without posing a threat of release of hazardous waste to the environment (40
CFR 260'. 10 and 264.196 '(51 Federal Register 25471 and 25477)). Such a system
or component must be immediately removed from service (pursuant to 40 CFR
264.196 (51 Federal Register 25477)). In addition, tank systems with leaks
from portions that are not readily accessible for visual inspection must be
provided with secondary containment (40 CFR 264.196(e)(4) (51 Federal
Register 25477)). If the repaired or replaced tank system or component is
underground, a variance is not allowed because it is treated as if it were a
new tank system and, therefore, must have leak detection as required by
Section 3004(o) of RCRA. Questions 7 through 9 in Worksheet A-2 address"this
type of tank system.
A.2.1.4 Time Constraints
Because the requirement for installation of secondary containment, in most
cases, depends on the age of the tank system, the age of the tank system is
important for determining variance eligibility requirements. Also, because
time is needed to apply for the risk-based variance and for the Regional
Administrator to review the application, the'regulations require tank
owners/operators to provide advance notice of intent to apply for a variance.
The variance may be denied if the notice of intent to submit a variance is not
submitted on or before the required date. Worksheet A-3 addresses these time
constraints.
For existing tank systems (i.e., where construction began before July 14,
1986), the owner/operator must provide written notice of intent to conduct and
submit a demonstration for a variance from secondary containment to the
Regional Administrator 24 months prior to the date that secondary containment
must be provided (40 CFR 264.193(h)(1)(i) (51 Federal Register 25476)). For
new eligible or non-underground tank systems (i.e., where construction began
after July 14, 1986), this notice must be provided at least 30 days prior to
entering into a contract for installation (40 CFR 264.193(h)(1)(ii) (51
Federal Register 26576)).
If an existing tank system is used to store or treat EPA Hazardous Wastes
F020, F021, F022, F023, F026, or F027, then written notice must be provided
before January 12, 1987 (40 CFR -264.193(a)(2) (51 Federal Register 25477)).
If the age of the existing tank system is known and documented, and the system
is 13 or more years old as of January 12, 1987, then written notice must be
-------
OSWER Directive 9483.00-2
A-10
provided before January 12, 1987; if the tank system is less than 13 years
old, then written notice must be provided before the system becomes 13 years
old (40 CFR 264.193(a)(3) (51 -Federal Register 25474)).
If the age of the tank system is not documented, and the facility is less
than seven years old as of January 12, 1987, then written notice must be
provided before January 12, 1993; if the facility is seven years old or
greater but less than 13 years old as of January 12, 1987, then written notice
must be provided before the facility is 13 years old; if the facility is 13
years old or older, then written notice must be provided before January 12,
1987 (40 CFR 264.193(a)(4) (51 Federal Register 25474)).;
For tank systems that store or treat materials that become hazardous
wastes subsequent to January 12, 1987, the date that the material becomes a
hazardous waste must be used in place of January 12, 1987 in the above section
of the regulation. In place of January 12, 1993, written notice must be
provided six years after the date that the material becomes a hazardous waste
(40 CFR 264.193(a)(5) (51 Federal Register 25474)). For example, if the
waste becomes hazardous on October 21, 1990, this date should be used wherever
January 12, 1987 is found and October 21, 1996 should be used in place of
January 12, 1993 to determine when written notice must be provided.
A.2.2 Comparison of Chemical Concentrations to Standards
The purpose of this section is to present a format for comparing the waste
constituent concentrations in the tank system to established environmental
quality standards. For constituents that have established standards, this
comparison will provide an indication of the amount by which they' exceed the
standard. The greater this difference, the less likely a risk-based variance
application will be approved. This is because of the greater likelihood that
the exposure point concentration of the chemical will also exceed the
established limit. For example, a tank with a waste constituent concentration
1,000 times greater than a standard for that constituent will more likely
exceed the standard at the exposure' point of concern than a tank with the same
waste constituent but with a concentration only 10 times the standard. Of
course, chemical- and site-specific properties affecting mobility and
persistence of the constituents will greatly affect the present and potential
exposure point concentrations.
Comparison to standards involves examining the ratio of the concentration
of each waste stream constituent to its corresponding environmental quality
standard (if one exists). The standards used for this comparison are the
maximum contaminant levels (MCLs), maximum contaminant level goals (MCLGs),
federally-approved state water quality standards developed under the Clean
Water Act,uj federal ambient water quality criteria and adjusted criteria
"J States with specific numerical ambient water quality standards for
toxic chemicals include Alabama, Alaska, Arizona, Arkansas, Delaware, Florida,
Illinois, Indiana, Iowa, Kentucky, Louisiana, Minnesota, Mississippi, Montana,
Nebraska, New Jersey, New Mexico, North Dakota, Tennessee, Texas, Utah,
Vermont, Virginia, West Virginia, and Wisconsin. Appropriate agencies in
other states should be consulted to determine if such standards are currently
in effect.
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OSWER Directive 9483.00-2
A-ll
(adjusted for drinking water ingestion only), federal drinking water health
advisories, and other state criteria. Each of these standards is briefly
described at the end of this subsection.
Using Worksheet A-4, record the lower (minimum), upper (maximum), and
"representative" chemical concentration for each constituent in the tank "
system. Determination of the representative concentration should be based on
an analysis of all monitoring or inventory data, with the goal being to
represent long range trends. It may be appropriate to use a geometric or
arithmetic mean of some or all of the samples as the most representative
concentration, or it may be more appropriate to choose a- concentration that
reflects a time trend occurring in the tank. The next step in comparing
chemical concentrations to standards is to list all the standards that may
exist for each chemical.
For some chemicals, several standards may be available as comparison
values. In this case, highlight the most appropriate value for comparison
(e.g., with an asterisk on Worksheet A-4). Appropriateness is determined in
part by relevance of the criterion to exposure conditions at the site (e.g.,
exposed population characteristics, duration and timing of exposure, exposure
pathways) and in part by how recently the value was developed. Some criteria
have been developed recently and may reflect new information compared to older
values.
The final steps are to calculate the ratios of the tank constituent
concentrations to the standards, sum the ratios for each chemical within a
standard '(e.g., add all the MCL ratios), and then sum the ratios for each
chemical within the most appropriate standards (i.e., add all the most
appropriate standard ratios). Although this comparison of chemical
concentrations with environmental standards may not provide the applicant with
a clear decision on whether to apply for a variance, much of the information
will be needed for a risk-based variance demonstration.
Maximum Contaminant Levels (MCLs) are drinking water standards
promulgated under the Safe Drinking Water Act. MCLs are listed in Exhibit C-8
and are currently available for 16 specific chemicals (10 inorganics and 6
organic pesticides), total trihalomethanes (covers four chemicals), certain
radionuclides, and microorganisms. An MCL is health-based, but it also
reflects the technological and economic feasibility of removing the
contaminant from the water supply. An MCL for a toxic chemical represents the
allowable lifetime exposure to the contaminant for a 70 kg adult who is
assumed to ingest two liters of water per day.
Maximum Contaminant Level Goals (MCLGs) are also available and are
listed in Exhibit C-9.SJ MCLGs are entirely health-based and, like MCLs,
Sj MCLGs, which were formally known as recommended MCLs (RMCLs), serve
as guidance for establishing drinking water MCLs. EPA recently proposed MCLGs
for a group of synthetic organic chemicals, inorganic chemicals, and
microorganisms (50 Federal Register 46936-47022, November 13, 1985). EPA
.also proposed MCLs for the same eight volatile organic chemicals for which
final MCLGs were promulgated (50 Federal Register 46902-46933, November 13,
1985).
-------
WORKSHEET A-l|
WASH COHSIMUIHI CONCEN IKAT IONS ANO COMPARISON 10 STANDARDS
INSTRUCTIONS:
1. List all waste constituents (use additional worksheets if necessary).
2. Record each chemical concentration range .mil representative value.
3. Refer to Exhibits C-8 through C-12, and/or, lor federally-approved state water
quality standards, the appropriate sl.no .Kjcncy. to obtain established water
standards. Record the value of the standard, its source (i.e.. Maximum Contaminant
level (MCL), MCL Coal (HCIC), federally-approved state standard (fASS), Water
Quality Criteria (WQC), or Drinking Water Health Advisories (UWMA)), and any other
pertinent information (e.g., whether WQC value refers to a one-day or ten-day exposure).
Indicate the most appropriate standards for c;n:h chemical with an asterisk.
faciIi ty ID:
Date:
Analyst:
Qua Ii ty Control:
i|. Calculate the ratios of concentrations to sl.nuM rds.
5. Sum the ratios within a standard (e.g., add all MCI
of the most appropriate standards (no more Ui;m one
NCXT SUPS:
ratios), and sum the ratios
for each chemical).
If several representative concentrations exceed standards by several orders of magnitude,
applying for a variance.
then user may want to reconsider
ChemicaI
Chemical Concent rat ion
iwn i ______ .
Upper Hep res.
Lower
I stab Ii shed Water
Quality Standards
Value (mg/I ) Source
Ratio or Chemical
Concentration to Standard
Lower Upper Rep res.
1.
2.
3.
Iota I:
Host appropriate;
-------
OSVER Directive 9483.00-2
A-13
represent the allowable lifetime exposure to the contaminant for a 70 kg adult
who is assumed to ingest two liters of water per day.
Federally-Approved State Water Quality Standards developed under the
Clean Water Act are enforceable standards in that state. At a minimum, states
listed in footnote 4 have promulgated at least some federally-approved water
quality standards for specific toxic chemicals. The applicant is responsible
for determining the availability of applicable state water quality standards
for a site.
Federal Ambient Water Quality Criteria for the protection of human
health have been developed for 62 out of 65 classes of toxic pollutants (a
total of 95 individual chemicals have numerical health criteria). The health
criterion is an estimate of the ambient surface water concentration that will
not result in adverse health effects in humans. In the case of suspect or
proven carcinogens, concentrations associated with a range of incremental-
cancer risks are provided to supplement a criterion of zero. The federal
criteria are non-enforceable guidelines, which many states have used in the
development of enforceable ambient water quality standards. Exhibit C-10
lists federal ambient water quality criteria for specific chemicals.
For most chemicals, federal water quality criteria to protect human health
have been published for two different exposure pathways. One published
criterion is based on lifetime ingestion of both drinking water and aquatic
organisms, and the other is based on lifetime ingestion of aquatic organisms
alone. The calculations incorporate the assumption that a 70-kilogram adult
consumes 2 liters of water and/or an average of 6.5 grams of aquatic organisms
daily for a 70-year lifetime. Calculations can be made to derive an adjusted
criterion for drinking water ingestion only, based on the two published
criteria and the same intake assumptions. Exhibit C-10 presents the published
criterion based on lifetime ingestion of both drinking water and aquatic
organisms and the adjusted criterion for drinking water only. The adjusted
criterion is more appropriate than the non-adjusted criteria for sites with
potential contamination of ground-water sources of drinking water because they
are based on more realistic exposure assumptions (i.e., exclusion of aquatic
organism ingestion as an exposure pathway).
Drinking Water Health Advisories are provided by EPA, in addition to
MCLs, to drinking water suppliers as guidance on chemicals that may be
encountered in a water system, but for which no federal standard exists. The
Office of Drinking Water's nonregulatory health advisories are concentrations
of contaminants in drinking water at which adverse effects would not be
anticipated to occur. A margin of safety is included to protect sensitive
members of the population. The health advisory numbers are developed from
data describing noncarcinogenic endpoints of toxicity. They do not
quantitatively incorporate any potential carcinogenic risk from such
exposure. The Office of Drinking Water has recently developed health
advisories for 54 chemicals or chemical groups, and these values are
summarized in Exhibit C-ll. Under certain circumstances and when the
appropriate toxicological data are available, health advisories may be
developed for one-day, ten-day, longer-terra (several months to several years),
and lifetime durations of exposure.
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OSWER Directive 9483.00-2
A-14
A.2.3 Site Characteristics
This section identifies situations, types of information, and factors that
are related to the potential threat to human health and the environment posed
by leakage from a hazardous waste tank. This identification is based on
hydrogeologic considerations (Section A.2.3.1) and surrounding water use,
water quality, and land use considerations (Section A.2.3.2).
As with earlier sections, a question and answer format is used with the
worksheets. The questions are intended to be simple, relatively easy to
answer, and be directly applicable to assessing potential environmental
threat. These questions help identify situations that pose more of a risk
than others. Consequently, there is no "next step" as with earlier sections.
Comments are provided to assist with the interpretation of answers. It must
be kept in mind that the potential risk indicated by the answer to a
particular question may be influenced by other factors, as indicated by the
answers to other questions and the evaluation of additional factors.
It is recommended at this stage that the preliminary screening questions
of this section be answered using the best available (i.e., off-the-shelf)
information. Potential data sources for use in obtaining information to
answer questions are provided for applicants who want to obtain more accurate
information. These sections are intended to indicate to the applicant the
type of information that is required for the risk-based variance. Limited
availability of these data will require the applicant to gather additional
data. Consequently, if many data elements are not available, the applicant
may want to reconsider applying for a variance.
A.2.3.1 Hydrogeologic Considerations
Ground water is a valuable resource and often a major source of drinking
water. Therefore, the potential for contamination of this resource by leakage
from a hazardous waste tank must be carefully evaluated both in the process of
determining whether to apply for a risk-based variance from secondary
containment and in the review of such an application. Screening questions in
this section are designed to evaluate the potential for ground-water
contamination by possible leakage from a hazardous waste tank depending on
characteristics of the hazardous waste tank location. This evaluation can be
addressed through questions about significant hydrogeological characteristics
of a site which are important in pollution potential assessment.
Hydrogeological considerations comprise the major geologic and hydrologic
factors which affect and control ground-water movement into, through, and out
of an area, and include geographical and climatic considerations.
Generalizations about ground water availability and potential for
contamination can be derived from the assessment of these factors.
The screening questions of this section are presented in Worksheet A-S.
Whether the answer to a question puts a hazardous waste tank site at a higher
or lower risk for potential contamination is identified in the worksheets.
Questions are presented in approximate order of decreasing importance in
screening considerations. Again, the potential risk indicated by the answer
to a particular question may be influenced by other factors, as indicated by
the answers to other questions.
-------
WORKSHEET A-5
IIYIMOCIOI 00 IC CONS I Of HA r IONS
INSTRUCT IONS;
1. Provide a response to each question.
2. If tho applicant wants to provide moii; accurate responses
to the quest ions, the applicant may investigate ilie listed
data sources.
Sit PS;
1. If tho applicant has no knowledge or information relating to
the presented questions, or most response:. indicate a high
risk situation, applicant may want to reconsider applying Tor
a variance.
Faci I i ty II):
lank System:
Date:
Analyst:
Qua I i ly Com ro I :
Quest ion
Response
(yes/no)
Is the hazardous waste
tank located below the
water table level?
What is the depth to water
at the hazardous waste
tank site? a/
Data :>ource
Potentid I
Lower
JOsk
Higher
Commonis
Si te OperatlonaI
Records
U. S,G. S.
U. S.I). A. ( Soi I
Conservation Service)
local W.i tc r Supply
Aijenc ius and
Compantes
u. s.o. s.
U. S.I). A. ( So i I
Conserva t ion
So rvice )
tocal Water Supply
Agencies and
Compan i es
Well logs or hydrogeo-
locj ica I reports .
yes
ft.
<'ju ft. g/
Any leal-age results in immediate
contamination of ground water. Risk
associated with a "Mo" answer is
dependent on many other factors.
Determines the depth of material
through which a contaminant must
travel to reach an aquifer. The
extent of attenuation or removal of
contaminant generally increases with
increasing depth.
What is the tinsatitrated
zone at a hazardous
unsat-
waste tank site composed
of? b/
U.S. I). A. (Soil
Conservat ion
Service):
SoiI Maps
Soil Survey Reports
Shale Him or More porous materials such as sand
Silt/Clay Absent or gravel or the absence of an
Glacial Till Sand or tirated /one betweon the tank and the
Gravel ground water indicates faster trans-
Karst Lime- port of potential contaminants to
stone c/ ground water.
-------
WORKSlllEl A-'j (continued)
IIYUHOGLOLOGIC CONSJIHI1AI IONS
Quest ion
Response
(yes/no)
Data Source
J'B tOt! t' 0 I l< i.§ k
Lower Higher
Comments
Is the net recharge rate
high or low (0-2"/yr)
ground-
at ttio site? d/
Genera Ily.
u.s.u. s
Slate; Department of
Resources
local W.iter Supply
Agencies or Companies
U.S. I). A. (Soil Conser-
vat ion Service )
NOAA (National Weather
Sc'i v ice )
Low
High
Ccnoially, tin; gusitcr the recharge,
the greater tin: potential for
water contain inn t ion ilne to greater
transport to water utilu.
areas with nncoiil iiiecl aquifers and
high recharge ,in; at groator risk
than areas with confined aquifers.
Is the aquifer under a
hazardous waste tank site
confined or unconfirmed? e/
What is the composition of
aquifer media at hazardous
conta-
waste tank site? £/
U.S.C.S: Water Resources Confined
l)i vi si on
State Ocpa rtniunt of Water
Kcsonicos
Local W.itcT Supply
Aijoncius or Companies
U. S.«. S.
State Department of
Water Resources
local W.i te r Supply
C i us or Companies
Massive
Sha Ic
fractured
Bedrock
Unconfined Generally, unconfinod aquifers are
considered to In: at higher risk than
confined aquifers due to the ease of
contaminant movement into them.
Karst I ime- Aquifer media exerts the major con-
stone trol over the route and path a
Sand and minant must follow. If aquifer is
Gravel very deep, this consideration is
much less important.
Is the hazardous waste tank
located on or near to a
faultfs) °r fault zone?
ti.S.C.S. Geological Haps, No
liulletins, or Reports
Yes
These features can provide major
pathways of migration lor contami-
nant transport to ground water.
-------
WORKSIUff *-5 (continued)
IIYOItOCUOl 00 1C CONSIUtltAI IONS
Quest ion
He spoil se-
lves/no)
Data Source'
potent iaI Hi sK
Lower Higher
Comments
Is the hazardous waste tank
located in a flood-prone
area?
HOAA (N.it i(ina I Weather
Si:i v in:);
Hooding levels (ele-
vnlions
U. i>. C. S :
lopoi|raphic mnps
( b i i
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OSVER Directive 9483.00-2
A-18
Again, sources for obtaining data to answer the screening questions of
this section are identified on the worksheets. This information is not
intended to. be inclusive of all or even most of the sources for such
information. While not identified on the worksheets of Section A.2.3, when
the U.S. Geological Survey is listed as a data source, the representative
State Geological Survey may also serve as a data source, and may in fact offer
a more accessible and extensive (for local information) source of needed data.
A.2.3.2 Surrounding Water Use, Water Quality, and Land Use
Considerations
This section presents screening questions that are designed to assess the
impact or potential adverse effects to ground-water and surface water quality
from failure of and subsequent release from a hazardous waste tank system.
Consideration is given to the proximity of drinking water users, proximity of
surface water, current and potential usages of ground water, and potential
damage.to wildlife, crops, and vegetation.
Ground-water questions presented herein are intended to provide a general
indication of ground-water use and quality at a hazardous waste tank site.
For a more rigorous discussion on characterizing ground waters, readers are
directed to Chapter 4 of this document.
Owners or operators of hazardous waste tanks who can determine that ground
water surrounding or underlying their site is not a potential source of
drinking water and is of limited beneficial use would be more likely to apply
for a risk-based variance, since this would indicate no exposure pathway for
contamination. It should be noted, however, that a number of states have
their own ground-water protection policies, which may differ from the
characterization process presented here and thereby affect conclusions reached
regarding the appropriateness of a variance based on this characterization.
The screening questions of this section are presented in Worksheet A-6.
When answering questions, a two-mile radius from the sice or site boundaries
should be reviewed.'- Whether a question's answer puts a facility at a
potentially higher or lower risk is identified in the worksheet.
Considerations of other factors such as waste (Section A.2.2) and
hydrogeologic characteristics (Section A.2.3.1) are especially important for
owners or operators who find they are located near ground or surface water of
special or beneficial use.
A.2.4 Human Exposure
This section provides guidance, in addition to that provided in Section
A.2.3, on examining present or potential exposure pathways that may affect the
appropriateness of a variance from hazardous waste tank secondary containment
requirements. Identifying exposure pathways is important for two reasons. If
there are no present or potential exposure pathways, the applicant will not
*J EPA, Guidelines for Ground-Water Classification Under the EPA
Ground-Water Protection Strategy, Final Draft, Office of Ground-Water
Protection, December 1986.
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WORKSHEET A-6
SURROUNDING WAIfK US! , WAIER QUALIIY, AND LANL) USE CONS IOERAIIONS
INSIRUC1IONS:
I. Provide a response to each question.
2. If the applicant wants to provide more accurate responses
to the questions, the applicant may investigate tin; listed
data sources.
NEXT SIEPS:
1. IP the applicant has no knowledge or inTo mint ion relating to
the presented questions, or most responses indicate a high
risk situation then the applicant may want to reconsider applying
'for a variance.
faciIi ty 10:
Date:
Analyst:
Qua I i ty Com ro I:
Quest ion
Response
(yes/no)
Oata Source
Commonts
_-
Lower
Higher
Is the ground water at or
near the hazardous waste
tank site saline (or have
a total dissolved solids
(TDS) concentration over
10,000 mg/I) to an extent
which would not allow
drinking or other benefi-
cial uses?
Is ground water at a site
considered to be ecologi-
cally vital (i.e., does
ground water supply a unique
terrestrial or aquatic
habitat associated with
surface water bodies that
if polluted would destroy
a unique habitat)?
Sensitive ecological
include:
systems
a) Docs ground water at a
site supply a habitat
for an endangered or
threatened species of
animals and/or plants?
Nation Water Well Asso-
ciation library (Ohio)
U.S.G.S. :
Ha si (i Investigations
NAWDfX a/
Army Corps of Engineers
Local sources:
I* In lining boards
Government Councils
State t nv i rorimunta I
Protection Offices
State Universities
U.S. fish and
Wild! lie Sorv ice
State I nilaiiijeied Species
Coordinator
National Park Seivice
U.S. Co rest Service
U.S. Bureau of Land
Management
Army Corps of Engineers
Yes
No
If yes, and is hydrogeologicaIly
isolated and is of limited benefi-
cial use, may be appropriate to
continue screening and variance
process.
No
Yes
If ground water is ecologically
vital a successful variance
demon s t ra t i'on is unlikely.
No
Yes
Pursuant to the Endangered Species
Act of 1973.
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WORKSHEET A-6 (continued)
SURROUNDING WA 11 R USl . WAILH QUALI1Y, AND LAND USE CONSIDERATIONS
Question
Response
(yes/no)
Data Sou i <:i;
Potent ia | R i sk
Lower Hiqher
Comments
b) Is hazardous waste tank
located in wetlands?
No
Yes
c)
d)
Is hazardous
located in a
area?
waste lank
coastal
Is hazardous waste tank
located in any other
sensitive environmental
area -- such as water-
sheds selected by state
and local governments
for protection?
No
No
Yes
Yes
Wetlands arc ecologically sensitive
as they support vegetation adapted
Tor life in saturated soil condi-
tions. May be protected under state
statutes, the Clean Water Act, or
Executive Order 11990.
May be regulated under the Coastal
Zone Management Act, or State Coastal
Zone Management Programs.
Is ground water at or near
a hazardous waste tank site
"i rreplaceable"?
This can be assessed by the
following questons:
a) Does ground water serve
a substantial population?
b) Is ground water of sur-
rounding hazardous waste
tank site located in
areas where there is no
alternative source of
drinking water or an
insufficient alternative
source for a substantial
populat ion?
Local Welter Supply
Agencies and Companies
No
Yes
No
No
Yes
Yes
If ground water is irreplaceable and
highly vulnerable to contamination,
a successful variance demonstration
is unlikely.
A substantial population being
approximately 25UO people within or
near the 2-mile review radius, b/
Includes islands, peninsulas, and
isolated ground water over bedrock.
-------
WOHKSMfET A-6 (continued)
SURKOUNOING WAHK USI . WAILH QUALIIY, AND LAND USL CONS I OtRAT IONS
Quest ion
Response
(yes/no)
Data Source
Potential Risk
Lower Higher
Comments
Is ground water at or near
hazardous waste tank site
located in an aquifer desig-
nated as a Sole'Source Aquifer
under the Safe Drinking Water
Act?
Local W.IK!r Supply
Agencies and Companies
No
Yes
If yes, potential risk is greater.
Is ground water at or near
the site a current or
potential source of
drinking water?
Can be assessed by:
a) Arc there operating
drinking water wells
(or springs) in the area
(wi thin the 2-mj le
review radius)?
b) Would a well or spring
in the area be capable
of yielding a quantity
of drinking water suf-
ficient for the needs
of an average family
(150 gal/day)?
Is the hazardous waste tank
located near a scenic river
or recreational area such
that leakage of hazardous
waste would adversely affect
the area?
Local W.i te r Supply
Agencies and Companies
No
Yes
If yes. potential risk is greater.
National Park Service
County Recreation
Department
No
Yes
Such area's may be protected under
State statutory and/or regulatory
author!ty.
Are there agricultural
lands located in the area
of the hazardous waste
tank?
If so, can potentially
adverse effects be iden-
tified if leakage occurs
from a hazardous waste
tank?
U.S. Department, of
Agriculturn (SoiI
Conservation Service)
No
Yes
Protection policies are identified
in the USDA »arm I and Protection
Policy and the tPA's "Policy to
Protect Lnvi ronmeiita I ly Significant
Agricultural lands."
t *
-------
WORKSHEET A-6 (continued)
SURROUNDING WAUR USf. WATER QUALIIY. AND LAND USE CONSIDERATIONS
Question
Response
(yes/no)
Data Source
Potential Ris k_
Lower
Higher
Comments
Is hazardous waste tank
located such that releases
could migrate directly to
"drinking water or a drink-
ing water supply?
Local W.itor Supply
Agencies and Companies
No
Yes
If yos, can pose: a tin cat to human
hcaIth.
Docs ground water at or near
a hazardous waste site dis-
charge to surface water
bodies that serve as a
drinking water supply
U.S.G.S.
Has in Investigations
NAWDIX a/
Local Water Supply Agencies
and Companies
No
Yes
If yes. surface-water quality may be
degraded.
a/ National Water Data Exchange
b/ Source: EPA. Guidelines for Ground-Water Classification Under the EPA Ground-Water Protection Strategy. Office of
Ground-Water Protection, December 1986.
-------
OSWZR Directive 9483.00-2
A-23
need to demonstrate that containment concentration levels do not pose a
substantial hazard to human health and the environment. If, on the other
hand, exposure pathways are identified, then this information will be useful
for the risk-based variance demonstration.
An exposure pathway consists of four necessary elements: (1) a source and
mechanism of chemical release to the environment; (2) an environmental
transport medium (e.g., ground water, surface water) for the released
chemical; (3) a point of potential human contact with the contaminated medium
(referred to as the exposure point); and (4) a human ex-posure route (e.g.,
drinking water ingestion) at the exposure point. Exhibit A-l illustrates the
elements of an exposure pathway. Each pathway therefore describes a unique
mechanism by which a population or an individual is exposed to contaminants
originating from a site. The overall risks posed by a site are a composite of
the set of individual pathway risks. Risks for individual pathways, however,
may not be additive because they may represent risks to different populations.
The analysis described here is a first-cut organization of the relevant
site information so that major exposure pathways can be defined. It is not
intended as a time-consuming task in the overall screening process.
Iterations of this procedure for the variance application will confirm the
important exposure pathways.
Although all four elements are necessary to identify an exposure pathway,
for this preliminary screening process, the applicant can assume the chemical
release is due to either a catastrophic event or a slow leak due to a seam
crack or corrosion hole. The necessary steps for the remaining three elements
are described below.
Identify Environmental Transport Medium. Using professional
judgment and knowledge of the surrounding environment, the
applicant should determine whether or not ground water or
surface water is nearby.
Identify Potential Exposure Points. The applicant needs to
identify the point of future use of ground water and/or surface
water that would result in the highest individual exposure
(usually the facility boundary) as well as the point of current
use of ground water and/or surface water that would result in
the highest individual exposure.
Identify populations that could potentially be exposed. The
applicant needs to identify the population that may be exposed.
The exact number of people is not necessary at this point, but
the applicant should identify whether the source is or will be
used to serve a large municipality or private wells. In
addition, the applicant should identify if a sensitive
population, such as elderly people or children, is a large
portion of the potentially exposed population.
Worksheet A-7 provides a matrix to screen potential exposure pathways
associated with ground water and surface water. First, identify if ground or
surface water is nearby. Then identify if potential exposure points (e.g.,
-------
-------
HOHKSIIEET A-7
SCKIININC OF POIENTIAL EXPOSURE PAIIIWAYS
INS1HUCTIOHS; facility II):
1. List all release sources and median i sins by release medium. Onto:
2. Describe the nature of the exposure point nnd its location Analyst:
with respect to release source (e.g., nearest potable well
to release site. SOU feet NW). Denote significant exposure Quality Control:
points with an asterisk.
3. List exposure route (e.g., ingesiion).
/I. Report the number of people potentiaIly exposed at the exposure point.
5. Determine number, location, and nature of sensitive population.
6. Mark where exposure pathways are complete (i.e., where release source,
transport medium, exposure point, and exposure route all exist).
Release/ Release Source/ Exposure Exposure Number of Sensitive: Pathway
Transport Medium a/ Mechanism Point Home People Population Complete
Ground water
Surface water
a/ Direct air exposure need not be considei o
-------
uirective
A-26
facility boundary, private wells, irrigation wells) exist and the number of
potentially exposed individuals. A complete exposure pathway is one that has
all necessary components: a mechanism of chemical release (e.g., catastrophic
release), environmental transport medium (e.g., ground water or surface
water), a potential exposure point, and an exposure route (e.g., ingestion of
contaminated drinking water by the exposed population).
Upon complccion of Worksheet A-7 the applicant should carefully review the
information. In particular, the applicant should consider the reliability of
the information presented in the worksheet. For example, the applicant may
know of some nearby private wells and a large development complex farther from
the tank facility. The applicant should not consider the conclusions reached
from the worksheet to be reliable if the worksheet does not reflect knowledge
of the-drinking water source for the development complex.
The purpose of the worksheet is to provide the applicant with a
preliminary indication of the likelihood that a variance will be granted and
to help the applicant identify which approach should be taken to apply for a
risk-based variance. For example, if the applicant is unable to identify an
exposure pathway, then the applicant will likely focus the variance on the
demonstration of no exposure pathways. Alternatively, if an exposure pathway
is identified and the potentially exposed population is large, the applicant
may decide to forego the variance process.
A.2.5 Summary of Screening Process
The issues affecting a risk-based variance, most of which are addressed in
the above sections, are inherently related and, in many ways, overlapping.
This summary compiles these issues so that the potential applicant for a
risk-based variance from secondary containment may more easily determine the
next course of action; i.e., whether to not apply for a variance (due to being
exempt from secondary containment), install secondary containment, or apply
for a variance.
Secondary Containment Not Required. Certain exemptions, discussed in
Section A.2.1.1, result in secondary containment not being required.
Consequently, an application for a variance is not needed. These situations
are summarized below:
Generators of between 100 and 1000 kg per month of
hazardous waste who accumulate the waste for less than
180 days (or 270 days if the generator must transport
the waste greater than 200 miles);
Generators of less than 100 kg per month of hazardous
waste who accumulate less than 1,000 kilograms of waste;
Generators of acute hazardous waste that generate less
than one kilogram of acute hazardous waste in a month
and accumulate no more than one kilogram on site at a
time;
-------
OSWER Directive 9483.00-2
A-27
Tanks that do not contain free liquids and are located
in buildings with impermeable floors; and
Tanks and sumps that serve only as part of a secondary
containment system.
Variance Not Allowed. Certain tank systems must comply with the
secondary containment requirements. Consequently, for these tank systems a
variance is not allowed. These tank systems were addressed in Sections
A.2.1.2 and A.2.1.3 and are summarized below:
New underground, hazardous waste tank systems or
components;
Existing, underground, unfit-for-use tank systems or
components; and
Potential Necessary Future Data Gathering Efforts. The type of
information that is likely to be required for a demonstration of no
substantial hazard and/or no exposure pathway was presented in Sections A.2.2
and A.2.3. It should be noted that these sections only highlight the areas
for which more detailed information is likely to be required. If the
applicant has limited detailed information relating to these areas, then the
applicant may want to reconsider applying for a variance. Several options for
obtaining more detailed information are as follows:
Chemical concentrations at exposure points7-1 --
surface water or ground-water release modeling;
Hazardous and unstable terrain characteristics --
surveying, topographic map, geologic map;
Hydrogeologic characteristics -- hydrogeologic
study, including the installation of observation wells
and stratigraphic poreholes such that field tests can
be conducted; andlj
Surrounding water use and water quality -- conduct
procedure as outlined in Chapter 4 of this document.
7J Section A.2.2 was based on a comparison of chemical concentrations in
the tank to environmental quality standards. The purpose was to provide the
applicant with an indication of the degree to which tank hazardous constituent
concentrations are above or below the standards. If the concentrations in the
tank are below the standards, then the applicant will probably not need to
determine chemical concentrations at exposure points.
*J The amount of data necessary to characterize the stratigraphic units
within the unsaturated and saturated zones will increase with the increasing
heterogenicity of the zones.
-------
OSWER Directive 9483.00-2
A-28
Focus of Variance Application. The applicant can demonstrate no
substantial present or future potential hazard in one of two ways: 1)
demonstrating that no present or potential exposure pathways exist; or 2)
using appropriate environmental fate and transport models, toxicity
characteristics of the waste and estimated exposures to assess risks and
demonstrate that the concentration levels do not pose a hazard to human health
and the environment. Section A.2.4 presented a simplified procedure to
identify exposure pathways. If the applicant has confidence in the results, of
the procedure then che applicant can identify the likely focus of the variance
application. If the applicant is unsure of the results, but believes that no
exposure pathways exist, the applicant may want to initially pursue this
approach for the variance application as described in Chapter 5 of the
guidance manual.
The Agency is developing a screening tool program for use on an IBM
compatible personal computer. The purpose of this screening tool will be to
provide a preliminary indication of whether a tank system poses substantial
risk to human health and the environment. The screening tool will use
straightforward conservative, ground-water transport and exposure models.
These models will require information that is more extensive and less
accessible than that required for Appendix A. The Agency intends to make this
program available to Regional Administrators and variance applicants in the
near future. If the Agency is able to provide this program to the public, EPA
will publish a Notice of Availability in the Federal Register.
-------
OSWER Directive 9483.00-2
APPENDIX B
INFORMATION SOURCES FOR ENVIRONMENTAL AND
HYDROGEOLOGIC INFORMATION
Federal Agencies
U.S. Environmental Protection Agency, Headquarters (U.S. EPA)
--Office of Water Enforcement and Permits
--Office of Water Regulations and Standards
--Office of Water Programs Operations
--Office of Drinking Water
--Office of Ground-Water Protection
401 M Street, S.W.
Washington, DC 20460
(202) 735-9112
U.S. Geological Survey (U.S.G.S)
Water Resources Scientific Information Center
425 National Center
Reston, VA 22902
(702) 860-7455
U.S. Department of Agriculture (U.S.D.A)
--Agricultural Extension Service
--Soil Conservation Service
Washington, DC 20250
(202) 447-2791
Regional EPA Offices
Region I
Water Management Division
John F. Kennedy Federal Building
Boston, MA 02203
(617)223-7210
Region II
Water Management Division
26 Federal Plaza
New York, NY 10278
(212) 264-2525
Region III
Water Management Division
841 Chestnut Street
Philadelphia, PA 19107
(215) 597-9800
Region IV
Water Management Division
345 Courtland Street, NE
Atlanta, GA 30365
(404) 881-4727
Region V
Water Division
230 South Dearborn Street
Chicago, IL 60604
(312) 353-2000
Region VI
Water Management Division
1201 Elm Steet
Dallas, TX
(214) 767-2600
-------
B-2
OSWER Directive 9483'.00-2
Regional EPA Offices (cont'd)
Region VII
Water Management Division
726 Minnesota Avenue
Kansas City, KS 66101
(913) 236-2800
Region VIII
Water Management Division
One Denver Place
919 18th Street Suite 300
Denver, CO 80202-2413
(303) 293-1603
Region IX
Water Management Division
215 Fremont Street
San Francisco, CA 94105
(415) 974-8071
Region X
Water Division
1200 Sixth Avenue
Seattle, WA 98101
(206) 442-5810'
State Agency ContactsIJ and Federal Agency State Offices
Alabama
Department of Public Health
Environmental Health Administration
Public Water Supply Division
Montgomery, AL 36130
Water Improvement Commission
749 State Office Building
Montgomery, AL 36130
U.S. Geological Survey
Water Resources Division
University of Alabama
Oil & Gas Bldg - Room 202
P.O. Box V
Tucaloosa, AL 35486
(205) 752-8104
Geological Survey of Alabama
P.O. Drawer 0
University, AL 35486
(205) 349-2852
lj Source for State Agency Contacts: Wendy Gordon, A Citizens Handbook
on Groundwater Protection, (New York: Natural Resources Defense Council,
1984), pp. 162-170.
-------
OSWER Directive 9483.00-2
B-3
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Soil Conservation Service
State Conservation Office
Wright Building
138 South Gay Street
P.O. Box 311
Auburn, AL 36830
(202) 821-8070
Alaska
Water Quality and Environmental Sanitation Division
Alaska Department of Environmental Conservation
Pouch 0
Juneau, AK 99811
Division of Forest, Land and Water Management
Alaska Department of Natural Resources
323 East Fourth
Anchorage, AK 99501
Alaska Division of Geology and Geophysical Surveys
3001 Porcupine Drive
Anchorage, AK 99501
(907) 279-1433
U.S. Soil Conservation Service
State Conservation Office
Suite 129, Professional Building
2221 E. Northern Lights Boulevard
Anchorage, AK 99504
(907) 276-4246
U.S. Geological Survey
Water Resources Division
218 E. Street
Anchorage, AK 99501
(907) 271-4138
Arizona
Planning Division
Arizona Department of Water Resources
222 North Central, Suite 850
Phoenix, AZ 85004
-------
OSWER Directive 94d3.0u-
-------
OSWER Directive 9483.00-2
B-5
State Agency Contacts and Federal Agency State Offices (cont'd)
California
California Department of Water Resources
P.O. Box 388
Sacramento, CA 95802
California Division of Mines and Geology
California Department of Conservation
1416 9th St., Room 1341
Sacramento, CA' 95814
(916) 445-1923
U.S. Soil Conservation Service
State Conservation Office
2828 Chiles Road
Davis, CA 95616
(916) 758-2200 ext. 210
U.S. Geological Survey
Water Resources Division
855 Oak Grove Avenue
Menlo Park, CA 94025
(415) 323-8111
Colorado
Colorado Water Resources Division
Department of Natural Resources
1313 Sherman Street
Room 818
Denver, CO 80203
Colorado Water Quality Division
Department of Helath
4210 East llth Avenue
Denver, CO 80220
Colorado Geological Survey
1313 Sherman St., Room 715
Denver, CO 80203
(303) 839-2611
U.S. Soil Conservation Service
State Conservation Office
2490 W. 26th Avenue
P.O. Box 17107
Denver, CO 80217
(303) 837-4275
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OSWER Directive 9483.00-2
B-6
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Geological Survey
Water Resources Division
Building 53
Denver Federal Center
Lakewood, CO S0225
(303) 234-5092
Connecticut
Connecticut Natural Resources Center
Department of Environmental Protection
State Office Building, Room 553
Hartford, CT 06115
Connecticut Geological & Natural History Survey
State Office Building, Room 553
165 Capitol Avenue
Hartford, CT 06115
(203) 566-3540
U.S. Soil Conservation Service
State Conservation Office
.Mansfield Professional Park
Route 44A
Storrs, CT 06268
(203) 429-9361/9362
U.S. Geological Survey
Water Resources Division
135 High Street - Room 235
Hartford, CT 06103
(203) 244-2528
Delaware
Delaware Department of Natural Resources
and Environmental Control
Water Supply Branch
Edward Tatnall Building
P.O. Box 1401
Dover, DE 19901
Delaware Geological Survey
University of Delaware
Newark, DE 19711
(302) 738-2833
-------
OSWER Directive 9483.00-2
B-7
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Soil Conservation Service
State Conservation Office
Treadway Towers, Suite 2-4
9 East Loockerman Street
Dover, DE 19901
(302) 678-0750
U.S. Geological Survey
Water Resources Division
Subdistrict-Dist. Office/MD
Federal Building - Room 1201
Dover, DE 19901
(302) 734-2506
Florida
Flordia Department of Environmental Regulation
Division of Environmental Programs
Groundwater Section
2600 Blair Stone Road
Tallahassee, FL 32301
Florida Bureau of Geology
903 W. Tennessee St.
Tallahassee, FL 32304
(904) 488-4191
U.S. Soil Conservation Service
State Conservation Office
Federal Building
P.O. Box 1208
Gainesville, FL 32602
(904) 377-3732
U.S. Geological Survey
Water Resources Division
324 John Knox Rd. Suite F-240
Tallahassee, FL 32303
(904) 386-1118
Georgia
Georgia Department of Natural Resources
Water Protection'Branch
270 Washington Street, S.W.
Atlanta, GA 30334
-------
. OSWER Directive 9483.00-2
B-8
State Agency Contacts and Federal Agency State Offices (cont'd)
Georgia Department of Natural Resources
Environmental Protection Division
Geological Survey and Water Resources Section
270 Washington Street, S.W.
Atlanta, GA 30334
Georgia Department of Natural Resources
Geological & Water Resources Division
19 Dr. Martin Luther King, Jr. Drive, S.W.
Atlanta, GA
(404) 656-3214
Soil Conservation Service
State Conservation Office
Federal Building
355 E. Hancock Avenue
P.O. Box 832
Athens, GA 30603
(404) 546-2274
U.S. Geological Survey
Water Resources Division
Suite B
6481 Peach Tree, Indust. Blvd
Doraville, GA 30360
(404) 221-4858
Hawaii
Hawaii Division of Water and Land Development
Department of Land and Natural Resources
P.O. Box 373
Honolulu, HI 96809
(808) 548-7533
U.S. Soil Conservation Service
State Conservation Office
300 Ala Moana Blvd.
Room 4316
P.O. Box 5004
Honolulu, HI 96850
(808) 546-3165
U.S. Geological Survey
Water Resources Division
P.O. Box 50166
300 Ala Moana Blvd.-Rm 6110
Honolulu, HI 96850
(808) 546-8331
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OSWER Directive 9483.00-2
B-9
State Agency Contacts and- Federal Agency State Offices (cont'd)
Idaho
Idaho Department of Water Resources
State House
Boise, ID S3720
Idaho Bureau of Mines & Geology
Moscow, ID 83543
(208) S85-6785
U.S. Soil Conservation Service
State Conservation Office
304 North 8th Street, Room 345
Boise, ID 83702
(208) 384-1601 ext. 1601
U.S. Geological Survey
Water Resources Division
P.O. Box 2230
Idaho Falls, ID 83401
(208) 526-2438
Illinois
Illinois Environmental Protection Agency
Public Water Supply Division
2200 Churchill Road
Springfield, IL 62706
Illinois State Water Survey
605 E. Springfield Avenue
P.O. Box 5050, Station A
Champaign, IL 61820
Illinois Scare Geological Survey
121 Natural Resources Building
Urbana, IL 61801
(217) 333-5111
U.S. Soil Conservation Service
State Conservation Office
Federal Building
200 W. Church Street
P.O. Box 678
Champaign, IL 61820
(217) 356-3785
-------
Directive
B-10
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Geological Survey
Water Resources Division
P.O. Box 1026
605 N. Nek Street
Champaign, IL 61820
(217) 398-5353
Indiana
Indiana Department of Natural Resources
Division of Water
608 State Office Building
Indianapolis, IN 46204
Environmental Health
Indiana State Board of Health
1330 W. Michigan Street
Indianapolis, IN 46206
Department of Natural Resources
Indiana Geological Survey
611 North Walnut Grove
Bloomington, IN 47401
(812) 337-2862
U.S. Soil Conservation Service
State Conservation Office
Atkinson Square-West Suite 2200
5610 Crawfordsville Road
Indianapolis, IN 46224
(317) 269-3785
U.S. Geological Survey
Water Resources Division
1819 North Meridan Street
Indianapolis, IN 46202
(317) 269-7101
Iowa
Iowa Natural Resources Council
Wallace State Office Building
East 9th and Grand
Des Moines, IA 50219
Iowa Department of Environmental Quality
Division of Water Supply
Wallance State Office Building
East 9th and Gran
Des Moines, IA 50319
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OSWER Directive 9483.00-2
B-ll
State Agency Contacts and Federal Agency State Offices (cont'd)
Iowa Geological Survey
123 N Capital
Iowa City, IA 52242
(319) 338-1173
U.S. Soil Conservation Service
State Conservation Office
693 Federal Building
210 Walnut Street
Des Moines, IA 50309
(515) 862-4260
U.S. Geological Survey
Water Resources Division
Federal Building - Rra 269
P.O. Box 1230
Iowa City, IA 52244
(319) 337-4191
Kansas
Kansas Oil Field and Environmental Geology
Department of Health and Environment
Topeka, KS 66620
State Geological Survey of Kansas
Raymond C. Moore Hall, University of Kansas
1930 Ave. A, Campus West
Lawrence, KS 66044
(913) 864-3965
U.S. Soil Conservation Service
State Conservation Office
760 South Broadway
P.O. Box 600
Salina, KS 67401
(913) 825-9535
U.S. Geological Survey
Water Resources Division
University of Kansas
1950 Avenue A, Campus West
Lawrence, KS 66045
(913) 864-4321
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OSWEK Directive 94S3.UU-2
B-12
State Agency Contacts and Federal Agency State Offices (cont'd)
Kentucky
Kentucky Division of Water Resources
Department for Natural Resources and
Environmental Protection
Capital Plaza Tower, Fifth Floor
Frankfort, KY 40601
Kentucky Geological Survey
University of Kentucky
311 Breckinridge Hall
Lexington, KY 40506
(606) 622-3720
U.S. Soil Conservation Service
State Conservation Office
333 Waller Avenue
Lexington, KY 40504
(606) 233-2749 ext. 2749
U.S. Geological Survey
Water Resources Division
Federal Building - Room 572
600 Federal Place
Louisville, KY 40202
(502) 582-5241
Louisiana
Office of Public Works
Louisiana Department of Transportation
and Development
1201 Capital Access Road
Baton Rouge, LA 70804
Louisiana Geological'Survey
Box G. University Station
Baton Rouge, LA 70893
(504) 342-6754
U.S. Soil Conservation Service
State Conservation Office
3737 Government Street
P.O. Box 1630
Alexandria, LA 71301
(318) 448-3421
U.S. Geological Survey
Water Resources Division
6554 Florida Boulevard
Baton Rouge, LA 70896
(504) 389-0281
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OSVER Directive 9483.00-2
B-13
State Agency Contacts and Federal Agency State Offices (cont'd)
Maine
*
Maine Office of Legislative Assistants '
State Capital
Augusta, ME 04333
Maine Geological Survey
State Office Bldg., Room 211
Augusta, ME 04330
(207) 289-2801
U.S. Soil Conservation Service
State Conservation Office
USDA Building ^_
University of Maine ~~~
Orono, ME 04473
(207) 866-2132/2133
U.S. Geological Survey
Water Resources Division
(District Office in Mass.)
26 Ganneston Drive
Augusta, ME 04330
(207) 623-4797
Maryland
Division of Water Supply
Maryland Department of Health and Mental Hygiene
201 W. Preston Street
O'Connor Building
Baltimore, MD 21201
Water Resources Administration
Maryland Department of Natural Resources
Tawes State Office Building
580 Taylor Avenue
Annapolis, MD 21401
Maryland Geological Survey
Merryraan Hall
Johns Hopkins University
Baltimore, MD 21218
(301) 235-0771
U.S. Soil Conservation Service
State Conservation Office
Room 522, Hartuick Building
4321 Hartwick Road
College Park, MD 20740
(301) 344-4180
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OSWER Directive 9483.00-2
B-14
State Agency Contacts and Federal Agency State Offices (con'td)
U.S. Geological Survey
Water Resources Division
208 Carroll Building
S600 Lasalle Road
Towson, MD 21204
(301) 82S-1535
Massachusetts
Massachusetts Department of Environmental
Management
Water Resources Division
100 Cambridge Street
Boston, MA 02202
Massachusetts Department of Environmental
Management
Water Resources Commission
100 Cambridge Street
Boston, MA 02202
Massachusetts Department of Environmental
Quality Engineering
Division of Waterways - Room 532
100 Nashua Street
Boston, MA 02114
(617) 727-4793
U.S. Soil Conservation Service
State Conservation Office
29 Cottage Street
Amberst, MA 01002
(413) 549-0650
U.S. Geological survey
Water Resources Division
150 Causeway St., Suite 1001
Boston, MA 02114
(617) 223-2822
Michigan
Water Quality Division
Michigan Department of Natural Resources
P.O. Box 30028
Lansing, MI 48909
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OSWER Directive 9483.00-2
B-1S
State Agency Contacts and Federal Agency State Offices (cont'd)
Michigan Department of Natural Resources
Geological Survey Division
P.O. Box 30028
Lansing, MI -8909
(517) 373-1256
Michigan Department of Public Helath
Water Supply Division
3500 N. Logan
P.O. box 30035
Lansing, MI 48909
U.S. Soil Conservation Service
State Conservation Office
1406 South Harrison Road
Room 101
East Lansing, MI 48823
(517) 372-1910 ext. 242
U.S. Geological Survey
Water Resources Division
6520 Mercantile Way - Suite 5
Lansing, MI 48910
(517) 372-1910
Minnesota
Minnesota Department of Natural Resources
Water Division
300 Centennial Building
St. Paul, MN 55155
Minnesota Pollution Control Agency
1935 West Country Road, B-2
Roseville, MN 55113
Minnesota Health Department
717 Delaware Street, N.E.
Minneapolis, MN 55440
Minnesota Geological Survey
1633 Eustis" Street
St. Paul, MN 55108
(612) 373-3372
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OSWER Directive 9483.00-2
B-16
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Soil Conservation Service
State Conservation Office
200 Federal Bldg. & U.S. Courthouse
316 North Robert Street
St. Paul, MX 55101
(612) 725-7675
U.S. Geological Survey
Water Resources Division
702 Post Office Building
St. Paul, MN 55101
(612) 725-7841
Mississippi
Bureau of Land and Water Resources
Mississippi Department of Natural Resorces
P.O. Box 10631
Jackson, MS 39209
Mississippi Board of Health
Mississippi Bureau of Environmental Health
Water Supply Division
Jackson, MS 39209
Mississippi Geological, Economic,
and Topological Survey
P.O. Box 4915
Jackson, MS 39216
(601) 354-6228
U.S. Soil Conservation Service
State Conservation Office
Milner Building, Room 590
210 South Lamar Street
P.O. Box 610
Jackson, MS 39205
(601) 969-4330
U.S. Geological Survey
Water Resources Division
Federal Building, Suite 710
100 West Capitol Street
Jackson, MS 39201
(601) 969-4600
-------
. OSWER Directive 9483.00-2
B-17
State Agency Contacts and Federal Agency State Offices (cont'd)
Missouri
Missouri Department of Natural Resources
Division of Environmental Quality
Water Supply Program
P.O. box 1363
Jefferson City, MO 65102
Missouri State Geological Survey
P.O. Box 250
Rolla, MO 65401
(314) 364-1752
Missouri Department of Natural Resources
Division of Environmental Quality
Public Drinking Water Program
P.O. Box 1368
Jefferson City, MO 65102
U.S. Soil Conservation Service
State Conservation Office
555 Vandiver Drive
Columbia, MO 65201
(314) 442-2271 ext 3155
U.S. Geological Survey
Water Resources Division
Mail Stop 200
1400 Independence Road
Rolla, MO 65401
(314) 341-0824
Montana
Montana Water Rights Bureau
32 South Ewing
Helena, MT 59620
Water Quality Bureau
Montana Department of Health and
Environmental Science
Helena, MT 59601
Montana Bureau of Mines & Geology
Montana College of Mineral Science
and Technology
Butte, MT 59701
(406) 792-8321
-------
OSWER Directive 9483.00-2
B-18
State Agency Contacts and Federal Agency State Offices fcont'd)
U.S. Soil Conservation Service
State Conservation Office
Federal Building
P.O. Box 970
Bozeman, MT 59715
(406) 587-5271 ext. 4322
U.S. Geological Survey
Water Resources Division
Federal Building - Drawer 10076
Helena, MT 59601
(406) 559-5263
Nebraska
Nebraska Department of Environmental
Control
301 Centennial Mall South
P.O. Box 94877
Lincoln, NE 68509
Nebraska Department of Water Resources
30T Centennial Mall South
P.O. Box 94676
Lincoln, NE 68509
Conservation & Survey Division
University of Nebraska
Lincoln, NE 68508
(402) 472-3471
U.S. Soil Conservation Service
State Conservation Center
Federal Building
U.S. Courthouse, Room 345
Lincoln, NE 68508
(402) 471-5301
U.S. Geological Survey
Water Resources Division
Federal Building/Courthouse - Room 406
100 Centennial Mall North
Lincoln, NE 68508
(402) 471-5082
-------
OSWER Directive 948-3.00-2
B-19
State Agency Contacts and Federal Agency State Offices (contrd)
Nevada
Scate Engineer
Nevada Department of Conservation and
Natural Resources
201 South Fall Street
Carson City, NV 89710
Nevada Bureau of Mines & Geology
University of Nevada
Reno, SV 89557
(702) 784-6691
U.S. Soil Conservation Service
State Conservation Office
U.S. Post Office Bldg., Rm 308
P.O. Box 4850
Reno, NV 89505
(702) 784-5304
U.S. Geological Survey
Water Resources Division
Federal Building - Room 227
705 North Plaza Street
Carson City, NV 89701
(702) 882-1388
New Hampshire
New Hampshire Office of State Planning
Division of Water Supply
2 1/2 Beacon Street
Concord, NH 03301
Office of State Geologist
James Hall
University of New Hampshire
Durham, NH 03824
(602) 862-1216
U.S. Soil Conservation Service
State Conservation Office
Federal Building
Durham, NH 03824
(603) 868-7581
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OSWER Directive 9483.00-2
B-20
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Geological Survey
Water Resources Division
Subdistrict-Dist. Off./Mass
Federal Bldg. - 210
55 Pleasant Street
Concord, NH 03301
(603) 224-7273
New Jersey
New Jersey Department of Environmental
Protection
Division of Water Resources
P.O. Box CN-029
Trenton, NJ 08625
New Jersey Bureau of Geology
& Topography
P.O. box 1390
Trenton, NJ 08625
(609) 292-2576
U.S. Soil Conservation Service
State Conservation- Office
1370 Hamilton Street
P.O. Box 219
Somerset, NJ 08873
(201) 246-1205 ext. 20
U.S. Geological Survey
Water Resources Division
Federal Bldg. Room 436
402 E. State St.
P.O. Box 1238
Trenton, NJ 08607
(609) 989-2162
New Mexico
Water Resources Division
New Mexico Natural Resources Department
Bataan Memorial Building
Santa Fe, MM 87503
Water Pollution Control Bureau
New Mexico Environmental Improvement
Division
P.O. Box 968
Santa Fe, NM 87503
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OSWER Directive 9483.00-2
B-21
State Agency'Contacts and Federal Agency State Offices (cont'd)
New Mexico Interstate Stream commision
Bataan Memorial Building
Santa Fe, NM 87503
New Mexico Bureau of Mines
& Mineral Resources
New Mexico Tech
Socorro, NM 87S01
(505) 835-5^20
U.S. Soil Conservation Service
State Conservation Office
517 Gold Avenue, SW
P.O. box 2007
Albuquerque,.NM 87103
(505) 766-2173
U.S. Geological Survey
Water Resources Division
Western Bank Building
505 Marquette, NW
Albuquerque, NM 87125
(505) 766-2430
New York
New York Department of Environmental
Conservation
Division of Pure Waters
50 Wolf Road
Albany, NY 12233
New York State Geological Survey
State Education Building
Albany, NY 12234
(518) 474-5816
U.S. Soil Conservation Service
State Conservation Office
U.S. Courthouse & Federal Bldg.
100 S. Clinton Street, Room 771
Syracuse, NY 13260
(315) 423-5493
U.S. Geological Survey
Water Resources Division
236 U.S. Post Office/Courthouse
P.O. Box 1350
Albany, NY 12201
(518) 472-3107
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OSVER Directive 9483'.00-2
B-22
State Agency Contacts and Federal Agency State Offices (cont'd)
North Carolina
North Carolina Department of Natural
Resources and Community Development
Division of Environmental Management
P.O. Box 27687
Raleigh, NC 27611
(919) 733-3833
U.S. Soil Conservation Service
State Conservation Office
310 New Bern Avenue,
Federal Bldg., Room 544
P.O. Box 27307
Raleigh, NC 27611
(919) 755-4165
U.S. Geological Survey
Water Resources Division
Century Station - Room 436
Post Office Building
P.O. Box 2857
Raleigh, NC 27602
(919) 755-4510
North Dakota
North Dakota State Water Commission
900 East Boulevard
Bismarck, N'D 58506
Division of Water Supply and
Pollution Control
North Dakota Department of Health
1200 Missouri Avenue
Bismarck, ND 58505
North Dakota Geological Survey
University Station
Grand Forks, ND 58202
(701) 777-2231
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OSWER Directive 9483.00-2
B-23
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Soil Conservation Service
State Conservation Office
Federal Building - Roser Ave. & 3rd
P.O. Box 1458
Bismarck, ND 58501
(701) 255-4011 ext. 421
U.S. Geological Survey
Water Resources Division
821 E. Interstate Avenue
Bismarck, ND 58501
(701) 255-4011
Ohio
Ohio Department of Natural Resources
Division of Water
Groundwater Section
Fountain Square, Building D
Columbus, OH 43224
Ohio Division of Geological Survey
Fountain Square, Bldg. B
Colurabu-s, OH 43224
(614) 466-5344
U.S. Soil Conservation Service
State Conservation Office
200 No. High St., Room 522
Columbus, OH 43215
(614) 469-6785
U.S. Geological Survey
Water Resources Division
975 West Third Avenue
Columbus, OH 43212
(614) 469-5553
Oklahoma
Chief, Planning and Development Division
Oklahoma Water Resources Board
P.O. Box 53585
N.E. 10th and Stonewall Street
Oklahoma City, OK 78152
Oklahoma Geological Survey
830 Van Vleet Oval, Rm. 163
Norman, OK 73019
(405) 325-3031
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OSWER Directive 9483.00-2
B-24
State Agency Contacts and Federal Agency State Offices Ccont'd)
U.S. Soil Conservation Service
State Conservation Office
Agriculture Building
Farm Road & Brumley Street
Stillwater, OK 74074
(405) 624-4360
U.S. Geological Survey
Water Resources Division
215 N.W. 3rd - Room 621
Oklahoma City, OK 73102
(405) 231-4256
Oregon
Groundwater Section
Oregon Water Resources Department
555 13th Street, N.E.
Salem, OR 97310
Oregon Water Quality Division
P.O. Box 1760
Portland, OR 97207
State Department of Geology and
Mineral Industries
1069 State Office Bldg.
1400 S.W. Fifth Avenue
Portland, OR 97201
(503) 229-5580
U.S. Soil Conservation Service
State Conservation Office
Federal Office Building
1220 S.W. 3rd Avenue
Portland, OR 97209
(503) 221-2751
U.S. Geological Survey
Water Resources Division
P.O. Box 3202
830 N.E. Holladay St.
Portland, OR 97208
(503) 231-5242
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' OSWER Directive 9483.00-2
B-25
State Agency Contacts and Federal Agency State Offices (cont'd)
Pennsylvania
Pennsylvania Department of Natural
Resources
Bureau of Water Quality Management
Box 1467
Harrisburg, PA 17120
Pennsylvania Bureau of Topography
and Geological Survey
Dept. of Environmental Resources
P.O. Box 2357
Harrisburg, PA 17120
(717) 787-2169
U.S. Soil Conservation Service
State Conservation Office
Federal Bldg. & Courthouse
Box 985 Federal Square Station
Harrisburg, PA 17108
(717) 732-4403
U.S. Geologial Survey
Water Resources Division
Federal Bldg. - 4th Floor
Harrisburg, PA 17108
(717) 782-4514
Puerto Rico
Director
Servicio Geologico de P.R.
Dept. of Recursos Naturales
Apartado 5887, Puerto de Tierra
San Juan, PR 00906
(809) 722-3142
U.S. Soil Conservation Service
State Conservation Office
Federal Office Bldg. Room 633
Mail: GPO Box 4868
Puerto Rico, San Juan 00936
Hato Rey, PR 00918
(809) 753-4206
U.S. Geological Survey
Water Resources Division
Building 652, Ft. Buchanan
G.P.O Box 4424
San Juan, PR 00936
(809) 783-4660
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OSWER Directive 9483.00-2
B-26
State Agency Contacts and Federal Agency State Offices (cont'd)
Rhode Island
Rhode Island
Water Resources Board
P.O. Box 2772
Providence, RI 02907
Rhode Island
Assoc. State Geologist for
Marine Affairs
Graduate School of Oceanography
Kingston, RI 02881
U.S. Soil Conservation Service
State Conservation Office
46 Quaker Lane
West Warwick, RI 02893
(401) 828-1300
U.S. Geological Survey
Water Resources Division
(District Office in Mass.)
Federal Bldg. & U.S. Post Office
Room 224
Providence, RI 02903
(401) 528-4655
South Carolina
South Carolina Water Resources Commission
Division of Hydrology
3330 Forest Drive
P.O. Box 4515
Columbia, SC 29240
South Carolina Geological Survey
State Development Board
Harbison Forest Road
Columbia, SC 29210
(803) 758-6431
U.S. Soil Conservation Service
State Conservation Office
"240 Stoneridge Drive
Columbia, SC 29210
(803) 765-5681
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OSWER Directive 9483.00-2
B-27
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Geological Survey
Water Resources Division
Strom Thurmond Federal Bldg.
1835 Assembly St., Suite 658
Columbia. SC 29201
(803) 765-5966
South Dakota
South Dakota Water and Natural
Resources
Joe Foss Building
Pierre, SD 57501
South Dakota State Geological Survey
Science Center
University of South Dakota
Vermillion, SD 57069
U.S. Soil Conservation Service
State Conservation Office
Federal Building, 200 4th St., S.W.
P.O. Box 1357
Huron, SD 57350
(605) 352-8651
Tennessee
Tennessee Department of Public Health
Bureau of Environmental Health
Division of Water Quality Control
Nashville, TN 37220
Tennessee Department of Conservation
Division of Water Resources
4721 Trousdale Avenue
Nashville, TN 37220
Tennessee Department of Conservation
Division of Geology
G-5 State Office Building
Nashville, TN 37219
(615) 741-2726
U.S. Soil Conservation Service
State Conservation Office
675 U.S. Courthouse
Nashville, TN 37203
(615) 749-5471
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OSVER Directive 9483.00-2
B-28
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Geological Survey
Water Resources Division
U.S. Federal 3uilding-A-413
Nashville, TN 37203
(615) 251-5424
Texas
Texas Department of Water Resources
Box 13087, Capital Station
Austin, TX 78711
Texas Bureau of Economic Geology
University Station, Box X
Austin, TX 78712
(512) 471-1534
U.S. Soil Conservation Service
State Conservation Office
W.R. Poage Federal Building
Temple, TX 76501
(817) 773-1711 ext. 331
U.S. Geological Survey
Water Resources Division
Federal Building - 649
300 East 8th Street
Austin, TX 78701
(512) 397-5766
Utah
State Engineer
Utah Department of Natural Resources
231 East 400 South
Salt Lake City, UT 84111
Utah Geological & Mineral Survey
606 Black Hawk Way
Salt Lake City, UT 84108
(801) 581-6831
U.S. Soil Conservation Service
State Conservation Office
4012 Federal Bldg.
125 S. State St.
Salt Lake City, UT 84138
(801) 524-5051
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OSWER Directive 9483.00-2
B-29
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Geological Survey
Water Resources Division
Administration Bldg. - 1016
1745 West 1700 South
Salt Lake City, IT 84104
(801) 524-5663
Vermont
Vermont Agency of Environmental Conservation
State Office Building
5 Court Street
Montpelier, VT 05602
(802) 828-3357
U.S. Soil Conservation Service
State Conservation Office
1 Burlington Square, Suite 205
Burlington, VT 05401
(802) 862-6501 ext. 6261
U.S. Geological Survey
Water Resources Division
(District Office in Mass.)
U.S. Post Office/Courthouse
Rooms 330B and 330C
Montpelier, VT 05602
(802) 229-4500
Virginia
Virignia State Water Control 3oard
P.O. Box 11143
2111 Hamilton Street
Richmond, VA 23230
Bureau of Water Supply Engineering
State Health Department
109 Governor's Street
Richmond, VA 23219
Virginia Division of Mineral Resources
P.O. Box 3667
Charlottesville, VA 22903
(804) 293-5121
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OSWER Directive 9483.00-2
B-30
State Agency Contacts and Federal Agency State Offices (cont'd)
U.S. Soil Conservation Service
State Conservation Office
Federal Bldg, Room 9201
400 N. 8th Street
P.O. Box 10026
Richmond, VA 23240
(804) 782-2457
U.S. Geological Survey
Water Resources Division
200 West Grace St. - Room 304
Richmond, VA 23220
(804) 771-2427
Washington
Washington Department of Ecology
Office of Water Programs
Water Resources Management
Olympia, WA 98504
Washington Dept. of Natural Resources
Geological & Earth Resources Division
Olympia, WA 98504
(206) 753-6183
U.S. Soil Conservation Service
State Conservation Office
360 U.S. Courthouse
W.920 Riverside Avenue
Spokane, WA 99201
(509) 456-3711
U.S. Geological Survey
Water Resources Division
1201 Pacific Ave - Suite 600
Tacoma, WA 98402
(206) 593-6510
West Virginia
West Virginia Department of Natural
Resources
Division of Water Resoures
1201 Greenbrier
Charleston, WV 25311
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OSWER Directive 9483.00-2
B-31
State Agency Contacts and Federal Agency State Offices (cont'd)
West Virginia Geological &
Economic Survey
P.O. Box 879
Morgantown, WV 26505
(304) 292-6331
U.S. Soil Conservation Service
State Conservation Office
75 High Street, P.O. Box 865
Morgantown, WV 26505
(304) 599-7151 .
U.S. Geological Survey
Water Resources Division
Federal Building/U.S. Courthouse
500 Quarrier St. East-Room 3017
Charleston, WV 25301
(304) 343-6181
Wisconsin
Bureau of Water Management
Wisconsin Department of Natural Resources
P.O. Box 7921
Madison, WI 53707
Wisconsin Geological & Natural
History Survey
1815 University Ave.
Madison, WI 53706 '
(608) 262-1705 '
U.S. Soil Conservation Service
State Conservation Office
4601 Hammers ley Road
Madison, WI 53711
(608) 252-5351
U.S. Geological Survey
Water Resources Division
1815 University Building
Madison, WI 53706
(608) 262-2488
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OSWER Directive 9483.00-2
B-32
State Agency Contacts and Federal Agency State Offices (cont'd)
Wyoming
Department of Environmental Quality
Water Quality Division
401 West 19th Street
Cheyenne, WY 82002
State Engineer
Barrett Building
Cheyenne, WY 82002
Wyoming Geological Survey
Box 3008, University Station
Laramie, WY 82071
(307) 742-2054
U.S. Soil Conservation Service
State Conservation Office
Federal Office Bldg.
P.O. Box 2440
Casper, WY 82601
(307) 265-5550 ext. 3217
U.S. .Geological Survey
Water Resources Division
P.O. box 1125
J C. O'Mahoney Federal Center
2120 Capitol Avenue - Room 5017
Cheyenne, WY 82001
(307) 778-2220
Private Organizations
The Nature Conservancy
National Office Heritage Task Force
1800 North Kent Street
Arlington, VA
(703) 841-5300
National Water Well Association
500 West Wilson Bridge Road
Worthington, OH 43085
(614) 846-9355
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OSWER Directive 9483.00-2
APPENDIX C
TABLES OF CHEMICAL-SPECIFIC DATA
Appendix ClJ contains the following six summary data tables:
Exhibit C-l: Physical, Chemical, and Fate Data
Exhibit C-2: Half-Lives in Various Media
Exhibit C-3: Toxicity Data for Potential Carcinogenic Effects
-- Selection of Indicator Chemicals Only
Exhibit C-4: Toxicity Data for Potential Carcinogenic Effects
-- Risk Characterization
Exhibit C-5: Toxicity Data for Noncarcinogenic Effects --
Selection of Indicator Chemicals Only
Exhibit C-6: Toxicity Data for Noncarcinogenic Effects -- Risk
Characterization
These tables summarize key quantitative parameters for more than 300
chemicals or chemical groups that were evaluated as part of the Superfund
reportable quantity (RQ) adjustment process or the intra-agency reference dose
(RfD) review process. These specific chemicals are included because of the
amounts of readily available toxicity information. This list should not be
interpreted as a complete list of chemicals of concern for hazardous waste
tank systems. Other substances may be important at certain facilities.
However, this appendix covers many toxic chemicals commonly stored and treated
in hazardous waste tank systems.
Chemical-specific parameters listed in the tables are primarily those
referred to in this manual, although a limited amount of other useful
information (e.g., CAS number, molecular weight) is also provided. Values for
physical, chemical, and fate parameters given in Exhibits C-l and C-2 are
provided for the convenience of the user and have not been fully peer reviewed
within EPA. Conversely, values given in Exhibits C-4 and C-6 for acceptable
intake level and/or carcinogenic potency have been reviewed within EPA and
should generally be used in the health effects evaluation of the risk-based
variance to secondary containment of hazardous waste tanks. The sources of
values and data transformation procedures, if any, are described in the
following sections.
In addition to the six data summary tables described above, a list of
chemicals for which EPA Health Effects Assessment documents are available is
provided in Exhibit C-7.
1J Appendix C is a copy of Appendix C in: EPA, Superfund Public Health
Evaluation Manual, Office of Emergency and Remedial Response, October 1986.
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OSWER Directive 9483.00-2
C-2
C.I EXHIBIT C-1: PHYSICAL, CHEMICAL, AND FATE DATA
The physical, chemical, and fate data shown in Exhibit C-1 were either
recorded directly from standard secondary references or were derived based on
information contained in such references. A general hierarchy of sources was
established, and values were taken from sources in order of the hierarchy. In
general, succeeding references were used only when a value could not be
obtained from a reference higher in the hierarchy. Priority was given to more
recent sources, and measured values were chosen over estimated values even if
obtained from a source lower on the hierarchy. The hierarchy of sources used
to select values for Exhibit C-1 is shown below and is 1'ettered to correspond
with the sources referenced in the exhibit. More complete reference
information for each of these sources is in the reference list for Appendix
C. A brief description of the derivation of values for e-ach parameter in
Exhibit C-1 follows the hierarchy listed below.
A) ECAO, EPA, Health Effects Assessments, 1985
B) Jaber et a_l. , 1984
C) Mabey et al., 1982
D) Calla'han et al. , 1979
E) ORD, EPA, 1981
F) Dawson et al., 1980
G) Lyman et ajL. , 1982
H) OWRS, EPA, 1980
I) Weast et al., 1979
J) Verschueren, 1983
K) Windholz et al., 1976
L) Perry and Chilcon, 1973
M) OSW, EPA, 1984b
N) OSW, EPA, 1984a
Water Solubility is the maximum concentration of a chemical that
dissolves in pure water at a specific temperature and pH. It is a critical
property affecting environmental fate and transport. Values for water
solubility, in mg/1, were recorded in Exhibit C-1 directly using the hierarchy
of sources and general decision rules outlined above. Values are given for a
neutral pH and a temperature range of 20 to 30 C. Chemicals listed in the
literature as being "infinitely soluble" were assigned a solubility value of
1,000,000 mg/1.
Vapor Pressure is a relative measure of the volatility of a chemical in
its pure state and is an important determinant of its rate of vaporization.
Values for this parameter, in^ units mm Hg, were recorded directly from the
hierarchy of sources listed above. Values are given for a temperature range
of 20 to 30° C.
Henry's Law Constant is another parameter important in evaluating air
exposure pathways. Values for Henry's Law Constant (H) were calculated using
the following equation and the values previously recorded for solubility,
vapor pressure, and molecular weight:
H(atm-m /mole) = Vapor Pressure (atm) x Mole Weight (g/mole)
3
Water Solubility (g/m )
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. OSVER Directive 9483.00-2
CT-3
Organic Carbon Partition Coefficient (Koc) is a measure of the tendency
for organics to be adsorbed by soil and sediment and is expressed as:
Ko'c = mg chemical adsorbed/kg organic carbon
mg chemical dissolved/liter of solution
The Koc is chemical specific and is largely independent of soil properties.
Most Koc values in Exhibit C-l were recorded directly from the above hierarchy
of sources. However, some Koc values were estimated using methods specified
in Lyman (1982). Estimated values are clearly designated as such.
Octanol-Water Partition Coefficient (Kow) is a measure of how a chemical
is distributed at equilibrium between octanol and water, and is used often in
the assessment of environmental fate -and transport for organic chemicals.
Additionally, Kow is a key variable used in the estimation of other
properties. For the convenience of the user, values for log Kow have been
included in Exhibit C-l. These values were recorded directly from the
hierarchy of sources referenced above.
Bioconcentration Factor as used in this manual is a measure of the
tendency for a chemical contaminant in water to accumulate in fish tissue.
The equilibrium concentration of a contaminant in fish can be estimated by
multiplying the concentration of the chemical in surface water by the fish
bioconcentration factor for that chemical. This parameter is therefore an
important determinant for human intakes via the aquatic food ingestion route.
Values for bioconcentration factors shown in Exhibit C-l were recorded
directly from the above hierarchy of sources.
C.2 EXHIBIT C-2: HALF-LIVES IN VARIOUS MEDIA
Chemical Half-Lives are used in this manual as measures of persistence,
or how long a chemical will remain, in various environmental media. Exhibit
C-2 presents values for overall half-lives, which are the result of all
removal processes (e.g., phase transfer, chemical transformation, and
biological transformation) acting together rather than a single removal
mechanism. All of the half-life values in Exhibit C-2 were recorded directly
from two sources, ECAO Health Effects Assessments (ECAO, 1985) and exposure
profiles for the RCRA Risk-Cost Analysis Model (OSW, 1984b). The same source
lettering convention was followed for Exhibit C-2 as for Exhibit C-l.
C.3 EXHIBIT C-3: TOXICITY DATA FOR POTENTIAL CARCINOGENIC
EFFECTS -- SELECTION OF INDICATOR CHEMICALS ONLY
For the risk assessment process outlined in this manual, data presented in
Exhibit C-3 are used only in the selection of indicator chemicals and not in
actual risk characterization.. These data were obtained from information
contained in the Reportable Quantity (RQ) data base (OHEA, 1986). The
procedures used to convert source data to the values given in Exhibit C-3 are
described briefly below.
The 10?; Effective Dose (ED ) represents the dose at which a 10 percent
incremental carcinogenic response is observed. This parameter was calculated
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OSWER Directive 9483.00-2
C-4
for both oral and inhalation routes by taking the reciprocal of the Potency
Factor Estimate (PFE) given in the RQ data base (this source defines PFE =
I/ED ; therefore, ED Q = 1/PFE). The ED.Q is in units of mg/kg/day.
Toxicity Constants vary for different exposure media. As such, Exhibit
C-3 contains toxicity constant values specific to water (wTc) and soil (sTc)
for the oral route, and a value for air (aTc) for the inhalation route. Each
of these conscants for potential carcinogens is based on the ED -, standard
intake assumptions for the respective media, and a standard body weight. The
specific equations and assumptions used to calculate the various toxicity
constants are presented and discussed in further detail in Appendix D.
C.4 EXHIBIT C-4: TOXICITY DATA FOR POTENTIAL CARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Data presented in Exhibit C-4 are for use in risk characterization, as
opposed to the selection of indicator chemicals. Values in this exhibit were
derived in the following manner.
Carcinogenic Potency Factors are upper 95 percent confidence limits on the
slope of the dose-response curve. These values were recorded directly from
HEAs or CAG summary tables, with the actual source cited in the exhibit for
each value and then fully referenced at the end of the exhibit. Potency
factors are used to estimate potential carcinogenic risk. These factors,
specific to different exposure routes, are given in Exhibit C-4 in units of
(mg/kg/day) .
Weight of Evidence ratings qualify the level of evidence that supports
designating a chemical as a human carcinogen. Exhibit C-4 lists ratings based
on EPA categories for potential carcinogens, which are fully itemized in
Exhibit D-2. The ratings were recorded directly from the RQ data base.
(Note: Weighc-of-evidence racings are also used in the procedure for
selecting indicator chemicals.)
C.5 EXHIBIT C-5: TOXICITY DATA FOR NONCARCINOGEN 1C EFFECTS --
SELECTION OF INDICATOR CHEMICALS ONLY
The data in Exhibit C-5 were generated based on information contained in
the RQ data base for chronic effects (ECAO, 1984). Values for the parameters
in Exhibit C-5, which are used in the selection of indicator chemicals but not
in risk characterization, were derived in the following manner. In addition,
chemicals marked in Exhibit C-5 with "@" also exhibit potential carcinogenic
effects. The reader is referred to Exhibits C-3 and C-4 for information
concerning these effects.
To determine the human Minimum Effective Dose (MED), the RQ data base was
reviewed to identify the studies with the highest composite score (a score
that combines MED and severity of effect) for oral and for inhalation exposure
routes. These MEDs were recorded under the appropriate exposure route in
Exhibit C-5. If composite score values were reported to be equal, the study
that yielded the lowest MED was used. For metals, one MED value was derived
-------
OSWER Directive 9483.00-2
C-5
from all studies for the various compounds of a given metal. Human MED values
are expressed in Exhibit C-5 in terms of mg/day. If an MED was available for
only one exposure route, it was recorded in Exhibit C-5 for the other exposure
routes _without modification unless the toxic effect was at the site of entry.
Severity of Effect Ratings, or RVe's, were recorded from the RQ data base
for the same study used to determine MED values. These rating constants are
unitless integers ranging from 1 to 10, corresponding to various levels of
severity of effects. The severity scale is presented in Exhibit D-l.
Toxicity Constants for noncarcinogenic effects, like those for
carcinogens, are specific to water, soil, and air and are designated in
Exhibit C-5 as wTn, sTn, and aTn, respectively. Again, these toxicity
constants are used only in the indicator chemical selection step of the
process. Values in Exhibit C-5 are based on standard intake assumptions as
well as a chemical's RVe and MED values. Ref.er to Appendix D for the specific
toxicity constant equations and for a discussion on their application.
C.6 EXHIBIT C-6: TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Exhibit C-6 gives values for parameters that are used in actual risk
characterization. The methods used to derive these values are described
below. Although the data in Exhibit C-6 are for noncarcinogenic effects,
several of the chemicals listed in the exhibit (those marked with an "(§") also
exhibit potential carcinogenic effects. Exhibits C-3 and C-4 should be
referred to for information concerning carcinogenic effects.
Subchronic acceptable intake (AIS) values are short-term acceptable
intake levels and are recorded directly from the appropriate HEA. Likewise,
values for chronic acceptable intake (AIC), which is the long-term acceptable
intake level for noncarcinogenic effects, were recorded directly from the
appropriate HEA or from compilations of Agency-verified reference dose (RfD)
values. These verified reference doses were developed by an EPA work group
chaired by the Office of Research and Development in 1985 and 1986. The
actual source used for each value is cited in Exhibit C-6 and is referenced
fully at the end of the exhibit. AIS and AIC are used to characterize risks
of noncarcinogenic effects. Both AIS and AIC values are in units of mg/kg/day.
-------
OSVER Directive 9483.00-2
C-6
REFERENCES FOR APPENDIX C
GAG, U.S. EPA, 1985. Relative Carcinogenic Potencies Among 54 Chemicals
Evaluated by the Carcinogen Assessment Group As Suspect Human Carcinogens.
Callahan e_t al. , 1979. Water-Related Environmental Fate of 129 Priority
Pollutants, Volumes I and II, Office of Water Planning and Standards, Office
of Water and Waste Management, U.S. EPA, EPA Contract Nos. 68-01-3852 and
68-01-3867. (Source D*]
Dawson, e_t a 1. , 1980. Physical/Chemical Properties of Hazardous Waste
Constituents. Prepared By Southeast Environmnetal Research Laboratory for
U.S. EPA. [Source F*]
ECAO, U.S. EPA, 1985. Health Effects Assessment for [Specific Chemical].
(Note: 58 individual documents available for specific chemicals or chemical
groups] [Source A*]
ECAO, U.S. EPA, 1984. Summary Data Tables for Chronic Noncarcinogenic
Effects. [Note: Prepared during RQ adjustment process]
Jaber, et al., 1984. Data Acquisition for Environmental Transport and Fate
Screening. Office of Health and Environmental Assessment, U.S. EPA,
Washington, DC, EPA 600/6-84-009 [Source B-]
Lyman, 1982, Adsorption Coefficient for Soils and Sediments. Chapter 4 in
Lyraan et al., Handbook of Chemical Property Estimation Methods.
McGraw-Hill, New York.
Lyman, e_t a_l., 1982. Handbook of Chemical Property Estimation Methods.
McGraw-Hill, New York. [Source G-]
Mabey, e_t al. , 1982. Aquatic Fate Process Data for Organic Priority
Pollutants. Prepared by SRI International, EPA Contract Nos. 68-01-3867 and
68-03-2981, prepared for Monitoring and Data Support Division, Office of Water
Regulations and Standards, Washington, DC. [Source C*]
OHEA, U.S. EPA, 1986. Methodology for Evaluating Reportable Quantity
Adjustments Pursuant to CERCLA Section 102, External Review Draft. OHEA-C-073.
ORD, U.S. EPA, 1981. Treatability Manual, Volume I, EPA 600/2-82-OOla.
(Source E-]
OSW, U.S. EPA, 1984a. Characterization of Constituents from Selected Waste
Streams Listed in 40 CFR Section 261. Prepared by Environ Corporation.
[Source N*]
*Source letters correspond to Exhibits C-l and C-2.
-------
OSWER Directive 9483.00-2
C-7
OSW, U.S. EPA, 1984b. Exposure Profiles for RCRA Risk-Cost Analysis Model.
Prepared by Environ Corporation. [Source M*]
OWRS, U.S. EPA, 1980. Ambient Water Quality Criteria Documents for [Specific
Chemical]. [Source H-']
Perry and Chilton, 1973. Chemical Engineers' Handbook, McGraw-Hill, 5th Ed.
[Source !/'"]
Verschueren, 1983. Handbook of Environmental Data for Organic Chemicals.
Van Nostrand Reinhold Co., New York, 2nd ed. [Source J*J
Weast e_t al. , 1979. CRC Handbook of Chemistry and Physics.' [Source I*]
Windholz, ejc a_l. , 1976. The Merck Index. [Source K*]
-Source letters correspond to Exhibits C-l and C-2.
-------
IXIIIDI I C-l
Date Prepared: October 1^
PHYSICAL. CHEMICAL, AND EAIE OA[A
Chemical Name
Acenaphthene
Acenaplitliy I e/ta
Acetone
Ace ton Itrile
2-Acetylaioinof luorene
Ac ryIi c Ac i d
Acrylonitrile
Aflaioxin 81
Aldlcarb
Aldrin
Ally! Alcohol
Aluminum Phosphide
'I-Ami nob ! phony I
Am i t roIe
Ammon i a
Anthracene
Antimony and Compounds
Arsenic and Compounds
Asliestos
Auramlne
Azaserine
A/i rid I no
Han urn and Compounds
honor in
benzene
Runzidine
f)enz( a (anthracene
Bcnzjcjacridine
ltcnzo( a Jpyrorie
llcnzoj b)n iiuranthnne
DOMZO( yli I )purylcn«
llenzoj K iriuoranthone
Bciizotrichloride
Benzyl Chloride
Beryllium arid Compounds
1, I-I) i phony I
Bis(2-chloroethyl)uthcr
Uis(2-chloroisopropyI(ether
Disjchloromethyl (ctlioc
Bis(2-ethylhcxyl )phthalate (Of III')
Uromomuthnni)
Bfomoxynil Ucianoate
1. 3-Biitadieiio
n-Butanol
Buty Iphtha lyl liutyly lycolatc
Cacodylic Acid
Cadiniun and Compounds
Captan
Carbaryl
Carbon Disulfide
Carbon letrachlor(do
Chlordane
Cnlorobenzene
Chlorobonzllate
Hole Mater
Moiyht Sol nb i 1 i ty
CAS t (y/mole) (mj/l) S»
83-32-9
/0-00-B
01-96-3
I'l- III- /
Id/- 1 1- 1
1 162-60-8
1 16-06-3
309-OO-2
10/-1II-6
21)809- / 1-8
92-6 /- 1
6i-a;'-'»
7 !><>'( -'( 1 - 7
K'(l- 1 if- /
/'i'ill-16-O
/'I'lO- 1U-2
1 3 3 (,
6.116
6.06
6 . '. 1
6.06
2.6J
1 . 00
«'. 10
0. 3(1
1.99
0 . OO
.-'. JO
;. if,
.'. DO
;*. Ci'i
j! i;1
i'.H'l
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; . 09
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c
j
i
ii
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c
c
a
u
it
r
A
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1)
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c
c
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C
A
A
C
f
C
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c
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r
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A
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II
II
II
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II
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r
ii
ii
u
-------
IXIIIBII C-l
(Com inued)
I'llYSICAL. CllfMICAl , ANO fAlt OA(A
Oato Prepared: Uciolioi 1,
Chemical Name
Chloroform
Chlorometliyl Hnlhyl llhor
l|-Chloro-o-to In idine llydrochlnr ide
Chromium I I I and Compounds
Chromium VI and Compounds
Chrysene
Copper and Compounds
Creosote
Crcsol
CrotonaIdehydo
Cyanides
-- ha Hum Cynnidii
-- Cntciura Cyanide
-- Coppur Cyanide
-- Cy.iiuxjun
-- <;y.iiioy<;n Chloride
-- Hydrogen Cyanide
-- Nickel Cyanide
-- Potassium Cyanide
-- Potassium Silver Cyanide
-- Si Iyer Cyanide
-- Sodium Cyanide
-- Zinc Cyanide
CycIuphospharoide
Oa Upon
01)0
1)1)1
Dccabrnmod iphenyI E tho r
Dial late
2. 'l -I) i aw i no to I no no
1,2,7,8-Oiben7opyrciio
0 i ben? ( a. It) anthracene
1 , 2-l)ibronio-3-chlorupropane
0 i billy I ni trnsamine
Uibtityl Phth.ilate
1 , 2-Dichlorohenzene
1 , 3-Oichlorohc;n?ene
1, 'i-Uichlorobcn?enn
3 , 3'-Qichlorouenzidine
Dichlorodi I I no i omo thii/ic
, 1-Oichlorocllinnc
.2-Oicliloruelh.iim (IDC)
, l-Uichloioethylone
. 2-Oichlorof:thy lene ( t rans |
,?-l)ichloroothylene (cis)
Dichlorniiietliane
2.l|-l)ichloioplienol
2. I* -1) i oh I o rophenoxy ace 111:
Acid (?,l(-0l
'!-(?, l«-l>f chlorophenoxy Jbiityi ic
Acid (2,I|-OI»)
Dichlorophenylarsino
1,2-Uichloropropane
Hole Water
WiMijht Sol lib i 1 i ty
CAS H (y/iunle) (iicj/l)
107-30-2
3160-91-1
/i|i|O~ 'l / ~ 3
/ (41*1(1 - i| / - J
2HI-OI-9
7<('(0-00-n
HOI) 1-011-9
1119-//-1
12 1- / 1-9
0/-I2-0
5'l2-fi2- 1
OO.'-OI-ft
S'l'l-9.'- 1
«(60- 19-0
006- //-'l
/'i-90-B
557-19-7
101-00-11
OU6-6 1-6
506-6»l-9
I'd- 1 1-9
507-21-1
Oo- in-o
/0-99-0
72-0'l-fl
/ 2 - 0 0 - 9
5O-29- 1
1 Hil-19-0
23U3- I6-'I
90-8O- /
109-00-9
0 J- 7O- 1
96- 12-fl
9/'l- 16-1
90-00- 1
O'l 1 - / 3- I
Io6-'i6- /
9I-9'I- 1
/ 0 - / 1 - 0
/O- I'l- 1
10 7-O6-2
/'.- lO-'i
O'lU-09-O
O'll) - 09 -O
70-O9- 2
120-111-2
V'l "/***"/
*^'l - 111* ~ (»
7I1-H7-5
1 19
81
02
228
6'i
NA
108
/O
NA
1119
92
90
02
61
27
102
60
199
1 3't
'(9
117
261
I'll
320
310
300
909
27<4
122
305
2/8
236
102
2/8
| J| /
I'l/
Hi 7
203
121
99
99
9/
97
97
BO
163
221
223
111
8
1
3
2
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1
5
8
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1
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5
1
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1
1
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7
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6
3
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6
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.801 -03
. 101 *O'(
.501*00
.501 »O3
.GOl«06
.OOL*05
.20t*05
. 31E*09
.OUE-OI
.OOE-02
.OOE-03
. MOf *OI
. 7/L*0'l
. tot -01
.OOE-O'I
.001 403
. 30E*I>I
.001 »02
.211 «02
.901 *0l
.001 *00
.801 »O2
.50L*03
.52f *03
.201*03
. 30O03
.501 «01
.OOI «l)l|
.601*03
.20E«02
. 701*03
S«
A
A
E
K
r
t
K
II
B
C
C
A
0
B
U
C
B
C
C
C
C
C
C
A
A
A
A
A
C
C
f
C
Vapor
Pressure
(mm lly)
0
0
6
0
2
1
6
1
6
5
6
3
1
1
1
1
2
1
1
li
1
6
6
3
2
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. OOE*00
.()()( «00
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.1(01-01
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. 891 -06
. 001 -06
.50L-06
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.801-05
.001-10
.ODE +00
.oor-05
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.2HI +00
. 1HI*00
.00( -00
.8/1 +O3
.02f+02
.1(01 +01
.001*02
.2'll »O2
.OOI *02
.621*02
.90E-02
.001 -01
.20L*OI
Henry's law
Constant Koc
S»( ai«-»3/mol ) (ml/9)
A
E
[
A
C
J
J
E
C
C
A
li
B
C
0
C
c
c
c
c
A
A
A
A
A
C
C
f
C
2
1
1
7
6
5
1
1
/
3
2
1
3
2
8
1|
9
3
6
7
2
2
1
2
.8/E-03
NA
NA
NA
NA
.05E-06
NA
NA
. IOE-06
NA
NA
.96E-06
.80E-O5
.UE-014
.65E-0»|
.28E-1IJ
NA
.33E-08
. 1 IE-Oil
NA
.02F-07
.91E-03
.59E-03
.89L-03
.33E-07
. 31E-03
.7HE-0'l
. 'iOF-02
.06C-03
.58F-03
.03F.-03
. /5E-06
.88t-0'l
NA
. 3IE-03
31
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0.01(2
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12OO
130000O
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k
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C
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k
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c
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-------
tXIIIBII C-l
(Continued)
PHYSICAL. CIIIMICAL. AND fAlE IMIA
Datu Pieparoil: October .1. 12fl6
Chonical Name
I,3-Uichlnruprupene
DieIdrin
Oiepoxybuiano
Dielhanolnitrosamine
Oictliyl Arsine
1,2-Die thy Iliydrazine
Oiutliy Ini trosawine
Diethyl Phlhalate
DiolhylKU Iliasirol (OtS)
0 i liyd rosa f role
Dime t homo
3,3' -Oimelhnxybenz idini!
Dimothylauunc
Dime thy I Sullalo
01moldy I lorephlha Iato
I) line thy la»ino»zobunzen;n-i|
l,'l|-i|ii- }
//- /It- 1
I2O-6 1-6
60- 1 1- /
5 / -9 7-6
1 19-91- /
/9-li'l- /
'jl- til-it
5'io- /i-ll
62- /5-9
9V-65-O
51 '1-52- 1
5 I-2U-5
602-01 - /
121- Ih-2
6 1 9 - 1 '. - a
6(16-211-2
61(1- 1 9 - 9
88-85- /
121-91-1
122- )9-'l
122-66- /
62I-6H-7
290-0'l-'l
1 15-29- /
IO6-B9-8
6'i- 1 7-5
Mil- /H-6
62-50-0
KIO-'II-II
5 10- 15-6
IO6-91-I|
/',-; |-||
96-'l5- /
/S9-/J-9
fjlj- /J'-o
9OO'i-6fi-l|
2O6-'l'|-O
116- / 1- /
//».'-' l-'l
59 /M.-oll-'l
'.O-on-O
1 1 1
301
a 6
13'!
1 3 'l
ea
102
222
260
16 'I
229
2'l'l
l5
126
I'V'l
225
?56
2 12
100
60
60
7'!
168
190
Id'l
182
182
102
182
1H2
2'lO
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169
ia'i
no
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-------
rxmDM c-i
(CuntInued)
I'llYSICAl, CHIMICAl, ANO I AIL UAIA
Date Proparuil: October Ai_!9.86
Chemical Name
fornic Acid
f uran
GlycidaIdehyde
Glycol Ethurs
-- Dicthylono Clycol,
Honoclhyl Ether
-- Z-Elhoxyeihanol
-- Elhylene Clycol,
Monobutyl Ether
-- 2-Methoxyeihanol
*- Propylene Glycol,
Monoeihyl Ethor
-- Propylone Glycol,
Monomelhyl Llher
llnptachlor
lleptachlor Epoxide
llexach I o rohenzerie
HexachIorolmladlene
Mexnclilorocyclopenl.iJ luni;
a Ipha-llexachlorocyc I oho xn no (IICCII)
biita-IICCII
gamma-IICCII (Lindane)
delta-IICCII
llexach loroeihane
lloxachlorophene
Hydrazinc
Hydrogen Sullide
lndcno(1,2.3-cd)pyrune
lodomelhane
I run and Compounds
Isobtiianol
Isopreno
I sosafrole
I Kopliorone
IsopropaI in
Kcpone
I n sioca rpinc
lead and Compounds ( I noi ijan i c )
Iinuron
Ma I all)ion
Manganese and Compounds
hclphnIan
Mercury and Compounds (A IKyI)
Mcicury and Compounds ( Inuiyanic|
Mercury fulminate
Melhanol
Mi: thy I Chloride
Ethyl Ketone
Ethyl Ketono I'IM oxide
Isobutyl Keionu
Methacrylate
Parathion
2-Mi: thy I -l|-»:hlorophoiioxyac:i!i ic
2(2-Melhy I l-'l-ChloiopliiMioxy-
propionic Acid
Methyl
ML; thy I
Miilhyl
Mtuhyl
Mijtiiyl
Ac i d
Mole
He icjht
CAS It (ij/mole]
6'l- II) -6
1 IO-OO-9
NA
1 1 1-90-0
1 10-BO-O
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120-08- t
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280
261
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291
291
291
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73E-09
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(Co/it I (Hied)
I'llYSICAL, CHEMICAL, AND fAlE DA IA
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o'l'-'.-lii-;'"0
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130
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Hi s :oi«N) I|9T f (Sfi«>l «<;<;'0-) = 30» B"l '"<>< i"nli:i (>uinii|(o| j»m K<\ pnieuniso oox JJ
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«|SI I
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jodcA JOICM o | OH
VIVO 3IVI
(1NV '
1V3IHIII3
'1V3ISAIM
(panui 11103)
1-3
II9IIIX 1
npii|(lsoi|,| out/ --
spuooilmo-j pue nil |/
(pax i ui) ouo|Ax
OpiJOI'13
spunodiuon puo
spiioodiiioo pue
pjcisnw I ! :>e'l)
on 11| UK I J |
UIIJJO|I|3I J
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( in j n | (iiiio ni ) uiici|loiiioinnj n ; J
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apixo ni
wit)
niuuoi|Ji'3 nil)
inn i
pue am | | ei|i
iXipoeiloi
:ps>JB«IOJH
-------
Cheuical Name
Acenaphlhenc
Acenaphthylene
Acetone
Acotonltrile
2-Aceiylaniinofluorene
Ac ryIi c Ac i d
Acryloni trile
AMatoxin 01
Aldicarb
Aldriu
AIlyl Alcohol
Aluminum Phosphide
'i - Am i nob i phony I
Am 11 ro I e
Aniiiion i a
Anthracene
Antimony and Compounds
Arsenic and Compounds
Asbestos
Aniamine
A2aserinn
Az i ridino
Barium and Compounds
HcneCin
Ounzenn
llcnzid me
IK:(iz(a (anthracene
l)i:nz(c (acrid ino
IK;nzo( a (pyrenc
(lun/oj ti) TI ci i-'i '> --.-i-?
Pl'lO- 3')- } *l . 80
IIU.I-'IO- 1
M-'U-;' 6.00
?<;;";'- \ ^°
50-lP-H l|20.00 M80.00 A 1.00 6.OO
205-VV-2 5.50
1 91 -:'!-?
20 /-!)»- 9
9U-0/-/
Idd-'l'i- /
1 1 l-'l'i-'l
100-6(1- 1
5l|2-IIH- 1 0. I'l 2.00
1 1 /-III- /
/
IOij-99-O
/I- 16-1
//'KI-ill-9 '1.80
1 1 )-()(,-?
Surface Water (.loiind Viator
S* low Iliijh S" low High S»
M 0. 125 - M
H /.(Id - H
H 2. II) /.OO II
5.OO - M
M I'lliS"" - M
M PI IIS - M
H HHS - M
M PIUS - H
A 1 .OO 6.0O A
H 0.10 5 . 00 H
A (1. 'id - A
H 1 . OO 2 . OO M
1 . 5O - H
M O.OOO/ - H
H PHIS - M
j- I'l-ll
6030.00
'10.00
3.50
A
H
A
0. 30
'I2O.OO
O. 30
300.00
5OO.OO
A
A
A
-------
ChenicaI Name
Ch lorod Ibromometliane
Chloroform
Chtoroom thy I Me .thy I Cihor
I|-Cli loro-o- lo I ii i d i ne llyd roch I or i do
Chromium III and Compounds
Chromium VI and Compounds
Cliryseite
Copper and Compounds
Creosote
Cresol
Cf 0100,1Idehydo
Cyanides
-- Barium Cyanide
-- Calcium Cyaindu
-- Copper Cyanide
-- Cyanoijcn
-- Cynnoijiiii Chloride
-- llydrmjen Cyanide
-- Nickel Cyanide
-- Potassium Cyanide
-- Potassium Silver Cyanide
-- Si Ivor Cyanide
-- Sodium Cyanide
-- Zinc Cyanide
Cyc lophosphaniide
Dalapon
DDO
OOP
DOI
DecahroroodiphenyI Ether
Dial laic
2, 'i-Oiaminolo luene
1,2. 7,8-Dibenzopyiene
l)i benzf a, h )anthracene
1,2-Oibroino-3-i:hloro|>ropaiio
Oiliutylni tros.imine
Diliulyl Phthnlate
.2-Oichlorobenzone
, 3-l)ichloiolien?cne
. l| - 01 cli I o rolHin/ei te
, 3 ' - D i i:h I o rnbiii iz i d i no
)ich I o roil i 1 I no mine t ha no
, l-l)i<:hf oroutlianc
.2-l)icliloio«:ili;in«; (IDC)
. l-l)ichloioelliylone
.?-Oichloroelhylone ( ir.ins)
. ?-Oichlui oulhyleiie (i; i b )
Dichloroineihanc
2,'i-Oichlornplionol
2 l|-l)ichloi ophonoxy.icel ic
Acid (2,11-1))
Acid (2,l|-l)ll)
CAS H
6 / -66-1
lll/-1ll-^
lid1)-'))- J
^ iii-m -y
/'I'ni-'iii-n
1I-/-/I-3
',116- //-ii
/'I-9D-H
l'il-JJ-9
t> >/-?!- 1
jll- IH-0
'ju -;><)- 3
1 161- !')-'>
'J3-/0-1
Half-life llnnijn (l).iys)
Soi 1
lliijli
Air Surfaco V/.m:i
low High S* low lliijli
i.iiiiinil
low
W.i lit r
lliijli
S»
looo.uo 5^00.00 A
80.00
'l.Hll
26.00
23.00
36.01)
?.00
?.1O
i . 30
'j3.^o
?.30
12/.00
O.3O 3O.IIO A
H 3. DO
H O.20
H 0.33
0 . 0208
II
M
0.80 M
t>6.()() HO. 01)
2.08
H
H
A
A
A
A
A
M
M
1
1.
1.
1).
1 .
1
1.
1
6
.';0
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.00
. I/
.OO
00
,(IO
.I'll
.DO
a
a
'>
6
6
6
'j
.'JO
.!»0
.11(1
-
.Ill)
.(III
. im
.80
-
M
M
A
A
A
A
A
M
M
-------
Chemical Nnmu
Oiclilorophenylarsine
1,2-Oicliloropropanc
1. 3-l)ichloropropene
Dieldrin
Dicpoxyhtitane
Ilieilianolni tiosamine
Dicthyl Arsint)
1.2-Diethylhydrazme
Diethy Ini I rusaame
Dietbyl Pbihalale
Diothy1stiIbostrol (DCS)
Diliydrosafrole
Dimothonte
3. 3' -Oinicllioxybenz id i ne
Oimuthy lamuiR
Dimethyl Snlf.itu
Dimethyl lerejihl ha In tc
I)iiimthy (aminunzobenzoiii;
/, 12-Dimethylbcnz(a)anthrucene
3.3* -I) i me thy Ibenz idine
Uimethy Icnrb.iiuoy I Chloride
I, I-Dimelhy Iliydraz mo
I,?-DimcthyIhydraz inc
Oioictnylni t rosamine
1. 3-Dmi trolionzene
I|,6-Dini lro-o-cresol
2. 'i-Dini trophcnol
2,3-Dini trotoluene
i irotoliiunu
2,6-l)ini trotolnoni;
l,ii-l)ini l ro toluene
Oinosob
I.il-Uiox.inu
N,N-l)i|)licMiy l.iniinu
I . ?-l)i|ihcny Iliydraz me
Dip ropy I (i i trosamioe
l)i snl loion
iDdo&till'iin
[[tjchloruliydrin
rthanol
Ithyl Auetatn
I thy I Molhanosul fonate
I thy I benzene
I thy I -'l,l| ' -dichloroben/1 i late
Lthyluiin Uibiomide (I 1)11)
I thy I one Oxide
I ihylKitcuhKiurca
1-1 thy I -ni irosonrna
I lliylplitlialyl flnyl Clyi.-olali;
lorric Dnxtmn
I liiorniilheno
I Inoriiiie
(.AS X
(,')(,-,'U-ti
IB-ttl-->
60-S/-I
I I U.-SH-f
H,is-nn-i
','>- \n-'j
U'l-66-2
sr.-si-1
9'i-SB-6
11- Itt- \
l.'0-li l-(l
611-II-/
S/-V/-A
IIV-V1-/
0/-l'l-'l
Sim- / »-a
cn;'-()l- /
l.M- l'i-?
(> IV- IS-tt
6ii6-;Mi-;'
(i Hi- lv-9
ll(l-fl'>-/
KM-VI-I
IIV- Jv-'i
I.V-6f. - /
(>',' >-t,>i- 1
uif,-n')-n
6'l-l/-S
l'il-/ll-6
6;'-Ml-(i
IIMI-|||-'I
S 10- IS -6
HK,-'M-'i
/'j-i'l-ll
'H,-it'i- I
/S'J- / 1-9
H'I-/,'-II
1XIIIUII i:~2
(Corn inuud)
Date Crejiared: UcKibur_ I . .J2S6
IIAll-LIVIS IN VAUIOUS HI I) I A
llnir-lil'e llancjn (li.iys)
Sufi Air Surface W
-------
Chemical Name; CAS
fluorides //li;'-i| l-l|
I Kir I done VJ/'jd-i.o-'i
formaldehyde MJ-IIII-O
I urnic Ac id f.'i- IH-i.
luran I ID-DO-')
ClycIdaIdohydo Id')- 3'i-'i
Glycol fibers HA
-- Dieihy luiio Glycol.
Monoelliyl filter MI-'JO-O
-- 2-Ethoxyclhanol I Ui-llii-'j
-- £ thy I one Clyi:ol.
Monobiiiy I I lliiii
-- 2-MutrioxyuLliiKiol
-- I'ropylijne (Jlycol,
Monoethyl drier 'iS \?'i-'t J-fl
-- Propyluno Clyool,
Monometliyl fttiur KI/-VH-?
llcpiaclilor /d-'|i|-n
Ht.'piachlGi ((.oxide l(l.''i-'i/-3
lluxachlornuun^ciic I la- /'i-1
Hcxnch loioluiiail luni; fl/-r,ft- I
lloxnchlonicyc lopniund tuiii; / /-'i 7*'i
(i Iplia-llcxachlorocyc lohiix.ine (IK.'CM) )IV-ll'i-(>
botn-IICCII 119-ft'j-/
ijainnia-IICCII (Luiilane) MI-ll'J-V
dolta-MCCII il'J-llfi-8
lluxiiclilorucllinnc (>!-!'.'- I
lli;xncliloro(>liuno /u- lu-'i
llyclraz ine 3l)^-iil-l
llyttrogen SulPidc //ll 1-uo-ii
iniluiiol 1,?. 3-cd)pyrene I9J- IV-'j
lodoinolhano //-HM-II
ron anil Compounds IMiia-ll-O
souutanol
sopruno
sosafi ole
sophoronc /tl-S'j-l
sopropalin 3 llt.'li-'> }-n
Kcponu li|3-Ml-l»
.T!, iDCiirpini! Id 1- I'l-'l
(;.H| and Conipdiuids ( linn giinii:) /'i I'*-1*.'- I
11 in i on J \(\-'j'j-'i'
Ma I ill hi on I.'I-/'<-/
H.IIKJ.HICSI; and Compounds /'i tv-')l>-'>
Molplialan UiM-IC'-i
MiMiMiiy and Coiii|ioiinds (Alkyl) /i|J9-9/-6
Mercury and Compounds I Inor yanu:) /'ilV-')/-6
Misri-'iiry fiilnnnalo 6,'(l-»jf<-'i
Molhanol (,l-'tl,-\
Mi.'lhyl Piloriilo /<(-»/-I
Moihyl fltiyl Koiorie /ll-'M-J
M«-'lliyl I lliyl Koioiic d.-ioxnlu I III)-.'' I -'I
MtUhyl Isobulyl Kuioru: lull-ID-I
rxillDII C-?
(Coin iiuicd )
IIAII-IIVIS IN VAIUOUS MLDIA
Dale Pruparcsd: ()i:iuliur _ I ,_L28(j
llair-lil'e Hanyo (Days)
bo i I
I <>w
High
Air
I ow II i
Sin face Wali.-r
S" low IlKjh
I ow
Wninr
lliijli
0.8U
M 0.90 3. '>) H
I1UU.UU 22UU.UU A
'Ul.OU
8O.OO
0. I'l
7900
H 0.96 - H
M (I. 3O IOO.OO A
H 20.00 230(1.00 A
M O.OO/ - II
I . II)
M O.O20B
9. '
2. Uli M
"1.80
l|.80
( ItS
I .1)1)
10.00
M
A
-------
Chemical Name
(.AS
Methyl Mclhacrylaie an-62-6
Methyl Parathlon 2liH-oo-0
2-Helhyl-'l-clil«rophcn
Hetliy I thiouraci I 'i6-(l'i-.'
MethylvinyInl irosanine iiVi'l-'iu-O
N-Mu thy I -N1 -ni t ro-N-ni t rosoyii.in.id in/o-,"i- /
Hi lomyc in C 0('-o/- /
Mustard Gas Ml'i-do-,'
l-Nnpthylaminc li'i-l.'-/
2-Naplhylamina yi-VJ-8
Nickel a»id Cnntpouiids /'I'lD-oi'-d
Nitric Oxido HMII2-l|}-9
Nitrobenzene ' Vll-V'j-1
Nitrogen Dioxide H)li)?-i|ii-o
Ni t ro some t liy In ro thane 6 I >-'>} -;
N-N i I rosop i per id i ne IDll-i
N-Ni trosupyirolid me
*>-N 11 ro-o- loin id ine
Osoiiiim leiroxide
l' l> 'i- l«>i i act) loi o
I XII11) I I C.-2
(ContInued)
Oalo I'reparcMl: "ctoliur I, .J286
MALI-LI VIS IN VAItlOOS Hi I) IA
llair-lifu Kaniju (l).iys)
So i I
I ow lliijli S"
Air
I ow Iliyli
SiirTace Waic:r (irouud Water
S* low lliqli S* I ow Iliijh S"
12. '
2) . 00 - M *). OO - M
O..J« 2.1)0 A
0.62 9.00 A 0.62 9.00 A
jB.OO - M 2.00 12.90 II
0.08 2.00 A
2.00
M
U,Ml. (Ill l| HID. (Ill
Jo'j.DO /JO.OO A
1 t
-------
Chemical Name
I. I. 1,2- JeiranliloroBtliaiie
1. 1 . 2,2-letrai:liloroelhano
leirachloroclliylene
2. 1,14.6-Jeirachloroplieiiol
2, J, >, 6- lei rachloroiur uphtlia lali;
Acid (OCI'A)
lot ractliy I lead
Ilia I Hum and Compounds
-- Thai inn Acetate
-- Dial i(im Car bonn lo
-- Ilia I I urn Chloride
-- Ilial iinu Nil (all;
-- lhal ic Oxide
-- lhal nun Sulfato
I hioacetaniido
Iliiourea
o - I <» I i d i ne
luiucno
o-loliiidine llydroclilordlc
Inxaphone
r ibrumoinelhane ( llroiiiol 01 m )
.2, 'i -I richloroben/eiie
, I , l-Iricliloruelliaiiu
, 1,2-1 r i cli loroe tliano
r ichloroethy lene
rjclilorfon
r icliloromonur Itioromutlianu
?, 'l , 5-T r i cli lorojiliciio I
2 . 'l , 6 - I r i <:! I oro(ilicn<) I
2.4,5-1 ricliloroplienoxyaceUc Acid
,2,1-1 richloropropano
, 1 ,2-Irichloro-1.2,2, -
tri f lunruutliane
rl s(2, 3-dibroinopropyl (pliospha to
rim t ro to I ue no (INI)
rypan Ulue
llracll Mil s Lard
Uranium and Compoufids
llriiihano
Vanadiiiro and Coinpotinds
Vinyl Clilurido
Warfarin
o-Xyli!iie
in- Xy lene
p-Xylenc
Xylenc (mixed)
7inc and Compounds
-- ^inc Phospliido
Zlneb
>(, )-dn-H
6MI-/1-V
7/9I-12-O
HI IO.'-i|'>- I
I ll'i- I;'-';
/'i'Ui-ia-6
6;'-V>-'_>
6;'-'>6-f«
I 1 9 - 9 1 - /
\oa-aa-j
6J6-;'i-5
8OOI-3'>-2
l'j-2'j-?
I;'O-H,'- I
/ I -'<*- 6
l'}-i>(i-'j
/V-lll-6
9')-9'>-'i
afl -06 - ?
yi-/(>-')
96- l8-'i
/6-lJ-l
\ '.'(,- I:'- I
IKl-'ii,-/
/.'-') /- I
r,(.-/'j-l
/'I'Ki-d I - I
!>l-/'j-6
/'I'm- (,;'-?
/'<-(il-'i
HI -HI-;'
IXIIIlll I C-2
(fontinued)
MALI-I I VIS IN VARIOUS HLOIA
Date Prepared: Uciolier 1. 1966
Hall-I i fe Itango (Days)
Soi 1
(.AS * Low Iliyh !
6JO-;'O-6
/<>- »!,-,
127-lH-il
!>«-9o-2
ini.i-j^- 1
n\-^lt>-?
Air
>" low 11*9(1 S"
U/.OO - . A
Surface W.IKM CKHIIK
1 ow Iliijh '.« | nw
1 . 'id - M
O.O'l - A
1.00 10.00 A
Iliijh S»
72.00
5.OU
A
A
1 . 10
ItO.OO
aoj.no
2'l.00
3.70
I .00
I7i2.00
A
M
A
A
A
0. 17
2.0O
1 . 2»
0. Ml
1.90
1 . 00
-
l'l.20
_
7 . OO
-
90 . 00
A
M
II
A
A
A
I .20
O.'jO
II.BO
20.00
M
H
1.00
I . OO
1 . 'j
puts
19.00
9.00
M
M
" tellers denote the son no ol the d.H.i, ;is listed in Soclion C.I.
"* I'fHS indiciites tin; cluMiiica I i & pc;c s, i MCIIL fur' that need i nra.
-------
C-20
OSWER Directive 9483.00-2'
Date Prepared: October 1, 1986
EXHIBIT C-3
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY '-
Oral Route
Inhalation Route
Chemical Name
2-Acecylaminofluorene
Acryionitrile
Aflatoxin Bl
Aldrin
Amitrole
Arsenic and Compounds
Asbestos
Auramine
Azasenne
Aziridine
Benzene
Benzidine .
Benz(a)anthracene
Benz(c)acridine
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzotrichloride
Benzyl Chloride
Beryllium and Compounds
Bis(2-chloroethyl)ether
Bis(chloromethyl)ether
3 is(2-ethyIhexy1)phtha1 ate (DEHP)
Cacodylic Acid
Cadmium and Compounds
Carbon Tetrachloride
Chlordane
Chloroform
4-Chloro-o-toluidine Hydrochloride
Chromium VI and Compounds
Chrysene
Cyclophosphamide
ODD
DDE
DDT
Diallate
10%
Effective
Dose
(ED10)
mg/kg/day
2.
4.
1.
1.
/ .
1.
3.
3.
4.
4 .
6.
6.
8.
8
-
5
1
6
5
8
5
7
2
1
4
60E-02
39E-01
-NA
52E-02
39E-01
03E-03
NA
08E+00
NA
60E-03
70E+00
50E-04
92E-02
67E-05
28E-03
NA
NA
.91E-03
NA
NA
.23E-02
. 22E-04
.OOE^Ol
NA
NA
.52E-02
.61E-02
.08E-01
. 13E-01
NA
NA
.70E-02
.69E-01
.53E-01
.79E-01
.24E-01
Toxicity
Constant
Water
(wTc)
1/mg
1.
6.
1.
1.
4.
2.
7.
7.
6.
5.
4.
4.
3.
3.
3
5
1
*
5
3
5
3
1
1
6
10E+00
S1E-02
NA
88E-HDO
51E-01
07E-KXT
NA
66E-02
NA
93E+00
71E-03
34E+01
a IE -or
29E-HD2
55E-KDO
NA
NA
.21E+00
NA
NA
.47E-01
. 96E-H31
. 71E-04
NA
NA
.381+00
.32E-01
.63E-02
.51E-02
NA
NA
.01E-01
. 71E-02
. 13E-01
.59E-01
.74E-02
5 .
3.
9.
7.
2.
1.
3.
3.
3.
2.
2.
i
1.
1.
1
t
9
i
2
1
2
.1
5
7
3
Soil
(sic)
kg/mg
50E-05
26E-06
NA
40E-05
56E-06
03E-04
NA
33E-06
NA
97E-04
86E-07
17E-03
91E-05
14E-02
28E-04
NA
NA
60E-04
NA
NA
.74E-Q5
.98E-03
. S6E-08
NA
NA
.41E-05
. 16E-05
.81E-06
.76E-06
NA
NA
.50E-05
.86E-06
.64E-06
.97E-06
.37E-06
10%
Effective
Dose
(ED10)
mg/kg/day
2.
4.
1.
1.
7.
1.
3.
3.
4 .
4.
6.
6.
8,
1
3
*
5
1
i_
6
5
8
0
5
7
2
1
4
60E-02
39E-01
NA
52E-02
89E-01
03E-03
NA
08E+00
NA
60E-03
70E-MDO
50E-04
92E-02
67E-05
.28E-03
NA
NA
.91E-03
NA
.25E-02
. 23E-02
22E-04
OOEi-01
NA
.T3E-02
.52E-02
.61E-02
.08E-01
.13E-01
.57E-03
NA
. 70E-02
.69E-01
.53E-01
.79E-01
.24E-01
Air
Toxicity
Constant
CaTc)
(m3/mg)
1.
6.
1.
1.
4.
2.
; .
7.
6.
5 .
4.
4.
3.
i
3
^
5
i
i
&*
5
3
1
5
3
1
1
6
10E+01
51E-01
NA
asE+oi
5 1E+00
07E+01
NA
66E-01
NA
93E-01
71E-02
34E+02
SIE+OO
29E+03
55E-H31
NA
NA
,21E-t-01
NA
. 2SE-H31
.4TE-00
96E^02
. 7 1 Z - C 3
NA
. 65E*01
. 53E-01
. 32E-00
.63E-01
.51E-01
. HE-t-02
NA
.01E+OC
.71E-01
. ISE-t-OC
.59E-*-OC
. 74E-0'
-------
C-21
OSWER Directive 9433.00-2"
Date Prepared: October 1, 1986
EXHIBIT C-3
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
Diarainotoluene (nixed)
1,2,7,8-Dibenzopyrene
Dibenz(a,h)anthracene
1,2-Dibromo-3-chloropropane
Dibutylnitrosaraine
3,3'-Dichlorobenzidine
1,2-Dichloroethane (EDC)
1,1-Dichloroethylene
Dichloromethane
Dieldrin
Diepoxybutane
Diethano Lnitrosamine
Diethyl Arsine
1,2-Diethylhydrazine
Diethylnitrosamine
Diethylstilbestrol (DES)
Dihydrosafrole
3,3'-Dimethoxybenzidine
Dimethyl Sulfate
D methyl am inoazobenzene
7 ,12-Dime thy lbenz( a'(anthracene
3,3'-DinethyIbenzidene
Dimethylcarbamoyl Chloride
1,1-DimethyIhydrazine
1,2-Dimethylhydrazine
Dime thy Initrosajnine
Dinitrotoluene (mixed)
2,4-Dinitrotoluene
2,6-Dinitrotoluene
1,4-Oioxane
1,2-Diphenylhydrazine
Dipropylnitrosamine
Epichlorohydrin
Ethyl-4,4'-dichlorobenzilate
Ethylene Dibromide (EDB)
Ethylene Oxide
lor.
Effective
Dose
(ED10)
mg/kg/day
3
2
6
t
1
4
2
7
3
1
2
9
2
9
5
3
1
7
i
3
2
2
2
2
2
5
i
4
.40E-01
NA
.83E-03
.OOE-03
.29E-02
.20E-01
.88E-01
.33E-01
' NA
.81E-03
.58E-02
NA
NA
NA
.03E-03
.11E-04
.26E-01
.OOE-i-01
NA
.52E-03
.23E-06
.70E-02
.98E-03
.44E-02
.87E-04
.91E-02
.62E-01
.62E-01
NA
.94E-I-01
. 19E-01
NA
. 70E-MDO
.59E-01
.56E-03
. 13E-01
Toxicity Constant
Water
(wTc)
1/mg
8
1
4
1
2
5
1
3
7
2
1
3
1
3
3
7
1
3
1
7
1
1
9
1
1
5
1
6
.40E-02
NA
.01E-M31
.76E+00
.25E-MDO
.39E-01
.86E-02
.23E-01
NA
.66E+00
.98E-01
NA
NA
NA
.77E-MD1
.35E-t-02
.09E-02
.43E-03
NA
.OOE-'-OO
.46E-M33
.71E-01
. 44E-I-01
.84E-01
. 33E+02
.30E-01
.09E-01
.09E-01
NA
. 71E-04
.31E-01
NA
.06E-02
. 11E-02
. 11E+01
.91E-02
4
.
5
2
6
1
2
6
1
3
1
6
1
7
1
2
3
T
1
7
3
5
5
4
6
5
2
5
3
Soil
(sTc) '
kg/nig
.20E-06
NA
.04E-04
.3SE-04
.24E-05
.19E-05
.93E-06
.14E-06
NA
.83E-04
.99E-05
NA
NA
NA
.38E-03
.77E-03 .
.54E-06
.14E-08
NA
.50E-04
.73E-01
.36E-OS
.22E-04
.92E-OS
.65E-03
. 65E-05
.46E-06
.46E-06
NA
. 86E-08
.53E-06
NA
.29E-07
.56E-06
.57E-04
.46E-06
10%
Effective
Dose
(ED10)
mg/kg/day
3.
2.
6.
2.
1.
4.
2.
7.
3.
1.
2.
9.
2
9.
5 .
3.
l_ .
7 .
i.
3 .
2 .
2
2.
i
2.
5.
2.
4.
40E-01
NA
83E-03
OOE-03
29E-02
20E-01
8SE-01
33E-01
NA
81E-03
38E-02
NA
NA
NA
03E-03
11E-04
26E-01
OOE-HD1
NA
52E-03
23E-06
70E-02
96E-03
44E-02
87E-04
91E-02
62E-01
62E-01
NA
94E+01
19E-01
NA
70E+00
59E-01
56E-03
13E-01
Air
Toxicity
Constant
(aTc)
m3/mg
8.
1.
4.
1.
2.
5.
1.
3.
7.
2.
1.
3.
1.
3.
5 .
-
I _
3.
1.
~
1.
1.
9.
1.
1.
5.
1.
6.
40E-01
NA
01E-KJ2
76E+01
25E-KI1
39E+00
86E-01
23E-HDO
NA
66E+01
9SE-H10
NA
NA
NA
77E-HD2
35E+03
09E-01
43E-02
NA
OOE-01
'*6E*04
::E-OO
44£-r02
84E-00
33E-HD3
SOE-'-OO
09E4-00
09E-»-00
NA
71E-03
31E-I-00
NA
06E-01
11E-01
11E+02
91E-01
-------
C-22
OSVER Directive 9483.00-2-
Date Prepared: October 1, 1986
EXHIBIT C-3
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Chemical Name
Ethylenethiourea
Ethyl Methanesulfonate
1-Ethyl-nitrosourea
Formaldehyde
Glycidaldehyde
Hepcachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorobutadiene
alpha-Hexachlorocyclohexane (HCCH)
beca-HCCH
gamma-HCCH (Lindane)
Hexachloroethane
Hydrazine
Indenod ,2,3-cd)pyrene
lodomethane
Isosafrole
Kepone
Lasiocarpine
Melphalan
Methyl Chloride
3-Methylcholanthrene
4,4'-Methylene-bis-2-chioroaniline
Methylnitrosourea
Methylnitrosourethane
Methylthiouracil
Methylvinylnitrosamine
N-Methyl-N'-nitro-N-nitrosoguanadine
Mitoraycin C
1-Napthylamine
2-Napthylamine
Nickel and Compounds
N-Nitrosopiperidine
N-Nitrosopyrrolidine
5-Nitro-o-toluidine
Pentachloronitrobenzene
Oral Route
10*. 1
Effective
Dose
(ED10)
mg/kg/day
7.
5.
1.
<* ,
3.
8.
3.
8.
1.
1.
5.
5 .
1.
1.
1.
2.
2.
9.
1.
* .
8.
9.
3.
le 1.
1.
3.
5.
7 .
7.
69E-01
58E-03.
HE-Ol'
90E-02
45E-01
93E-03
45E-03
51E-02
69E-HDO
83E-02
75E-01
46E-01
25E+01
27E-02
NA
NA
67E+00
09E-02
66E-02
09E-04
05E+01
64E-02
20E-01
43E-05
NA
50E-02
NA
79E-02
NA
NA
98E-01
NA
88E-02
36E-03
14E+00
04E-01
foxicity Constant
Water
(wTc)
1/mg
3
5
2
5
8
3
3
3
1
1
4
5
2
2
1
1
1
3
2
o
3
3
8
1
1
7
5
4
4
. 71E-02
. 12E+00
.50E-01
.83E-01
.29E-02
.20E+00
.2SE-KJO
.36E-01
.69E-02
. 56E+00
.97E-02
.23E-02
. 29E-03
. 25E+00
NA
NA
.71E-02
.37E-*-00
.08E*00
. 1-E-KJ1
. 71E-03
. 16E-01
.^9E-02
.01E-rQ2
SA
. 16E-01
NA
.59E+00
NA
NA
.iiE-01
NA
.37E-01
.33E+00
.OOE-03
.06E-02
Soil'
(sic)
kg/mg
1
2
1
2
4
1
4
1
S
7
2
2
1
1
" 8
6
5
1
1
3
1
1
4
7
7
3
2
2
2
.86E-06
.56E-04
.25E-05
.92E-05
. 14E-06
. 60E-04
. 14E-04
.68E-05
.43E-07
. 79E-05
.49E-06
.61E-06
. 14E-07
. 13E-04
NA
NA
.57E-07
.35E-05
.3SE-05
.57E-03
.36E-07
.OSE-03
.74E-06
.51E-02
NA
.08E-05
NA
.97E-05
NA
NA
.21E-06
NA
.68E-05
.66E-04
.OOE-07
.03E-06
Inhalation
10%
Effective
Dose
(ED10)
tng/kg/ day
7.
5 .
1.
4 .
3.
8.
3.
8.
1.
1.
5.
5.
1.
1.
1.
2.
2 .
9.
1.
4 .
S.
9.
3.
1.
1.
1.
3.
5 .
7 .
7.
69E-01
58E-03
14E-01
90E-02
45E-01
93E-03
45E-03
51E-02
69E-KJO
S3E-02
75E-01
46E-01
25E-K31
27E-02
NA
NA
67E--00
09E-02
66E-02
09E-04
05E-K31
6-.Z-02
20E-01
48E-05
SA
50E-02
NA
79E-02
NA
NA
9SE-01
.OOE-01
.88E-02
,36E-03
, 14E+00
.04E-01
Route
Air
Toxicity
Constant
(aTc)
m3/mg
3.
5.
2.
5.
8.
3.
8.
3.
1.
1.
4.
5.
2.
1
1.
1.
1.
3.
i
6 .
3 .
->
8.
1.
1.
1
4. .
7.
5 .
4.
4.
71E-01
12E-I-01
50E-H30
83E+00
29E-01
20E+01
28E-KI1
36E-t-00
69E-01
56E+01
97E-01
23E-01
29E-02
25E*01
NA
NA
71E-01
37E-HD1
OaE+Ol
14E-02
71E-02
16E+00
49E-C1
01E-Q3
NA
16E^OO
NA
59E+01
NA
NA
44E+00
SSE-t-00
37E-»-00
33E-H31
OOE-02
06E-01
-------
C-23
OSVER Directive 9483.00-2
Date Prepared: October 1. 1986
EXHIBIT C-3
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Chemical Name
Pentachloropheno1
Phenacetin
Polychlorinated Biphenyls (PCBs)
Polynuclear Aromatic Hydrocarbons
Propane Sultone
1,2-Propylenimine
Saccharin
Safrole
Streptozocin
2,3,7,8-TCDD (Dioxin)
1,1,1,2-Tetrachloroethane
1,1,2,2-Tetrachloroethane
Tetrachloroechylene
Thioacetaraide
Thiourea
o-Toluidine hydrochloride
Toxaphene
1,1,2-Trichloroethane
Trichloroechylene
2 , 4,6-Trichiorophenol
Tris(2,3-dibromopropy1)phosphate
Trypan Blue
Uracil Mustard
Urethane
Vinyl Chloride
Oral Route
ior.
Effective
Dose
(ED10)
mg/kg/day
1.
5.
2 _
3.
2.
5 .
9.
8.
1.
6.
3.
4.
9.
6.
1.
2.
6.
1.
1.
i
1.
6.
NA
25E-M31
OOE-02
NA
85E-02
35E-02
44E-K12
OOE+00
17E-03
33E-06
20E+00
02E-01
23E-KDO
04E-02
52E-01
37E-01
02E-01
78E-H30
67E-HDO
25E+01
02E-01
78E-too
NA
56E+00
67E+00
Toxicity Constant
Water
(wTc)
1/og
2
5
1
8
1
5
3
3
2
4
8
7
3
4
2
1
u
1
2
1
1
4
NA
.29E-03
.71E-01
NA
.OOE+00
.53E-01
.17E-04
-71E-03
.12E-I-00
.43E+03
.37E-02
.74E-02
.86E-03
.07E-01
.OOE-02
.49E-02
.80E-01
.03E-02
.29E-03
.29E-03
.79E-01
.03E-02
NA
.83E-02
.29E-03
1
2
5
4
5
2
1
1
1
2
L
3
1
2
1
5
2
1
1
5
9
2
Soil
(sic) '
kg/rag
NA
.14E-07
.86E-05
NA
.01E-05
.27E-05
.86E-09
.86E-07
.56E-04
.71E-01
.19E-06
.37E-06
.43E-07
.54E-05
.30E-06
.24E-06
.40E-05
. 14E-07
.14E-07
. 14E-07
.39E-05
. 14E-07
SA
. 14E-07
. 14E-07
Inhalat
10%
Effective
Dose
(ED10)
mg/Xg/day
1
5
2
3
2
5
9
8
1
6
3
4
9
6
1
2
6
1
1
t
1
6
NA
.25E+01
.OOE-02
NA
.85E-02
.35E-02
.44E-I-02
.OOE-t-00
. 17E-03
.33E-06
.20E+00
.02E-01
.23E+00
.04E-02
.52E-01
.37E-01
.02E-01
. 78E-*-00
.67E+00
.25E-^01
.02E-01
.75E-00
NA
.56E*00
.oTE-i-OO
ion Route
Air
Toxicity
Constant
(ale)
m3/mg
2
5
1
S
1
5
3
3
2
4
8
;
3
4
2
1
4*
2
n
t
i.
i
^
NA
.29E-02
.71E-00
NA
.OOE-MD1
.53E+00
.17E-03
.71E-02
. 12E+01
.43E-^04
.37E-01
. 74E-Q1
.86E-02
.07E-*-00
.OOE-01
.49E-01
.80E-I-00
.03E-01
.29E-02
0 9 " - P, °
.79E-00
.C3E-C1
NA
.S3E-G1
.29E-02
l- The list of chemicals presented in this exhibit is based on EPA's Reportable
Quantities Analysis and should not be considered an all-inclusive list of suspected
carcinogens. Refer to Exhibit C-4 for toxicity data for risk characterization for the
chemicals listed here.
-------
C-24
OSVZR Directive 9483.00-1
Date Prepared: October 1. 1986
EXHIBIT C-4
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- RISK CHARACTERIZATION l-
Oral Route
Inhalation Route
Chemical Name '
2-Acetylaminofluorene
Acrylonitrile
Aflatoxin Bl
Aldrin
Amitrole
Arsenic and Compounds
Asbestos
Auramine
Azaserine
Aziridine
Benzene
Benzidine
Benz(a)anthracene
Benz(c)acndine
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzotrichloride
Benzyl Chloride
Beryllium and Compounds
Bis(2-chloroethyl)ether
Bis(chloromethy1)ether
Bis(2-ethylhexyl)phthalate (DEH?)
Cacodylic Acid
Cadmium and Compounds
Carbon Tetrachlcride
Chlordane
Chloroform
4-Chloro-o-toluidine Hydrochloride
Chromium VI and Compounds
Chrysene
Cyclophosphamide
ODD
DDE
DDT
f
J
mj
2.
1.
1.
5.
1,
1
6.
1
1
a
3
'otency
'actor
(PF)
5/kg/d)-l
90E-MD3
14E+01
50E+01
20E-02
. 15E-M31
NA
. 10E-HDO
.84E-04
NA
.30E-01
.61E+00
. 10E-02
NA
.40E-01
Source2- E
CAG
CAG
HEA
HEA
HEA
CAG
CAG
HEA
HEA
HEA
HEA
EPA Potency EPA
Weight - Factor Weigh
of (PF) of
Evidence (mg/kg/d)-l Source2-1 Eviden
B2 , E
Bl 2.40E-01 CAG I
B2 I
B2 !
B2 :
A S.OOE-i-01 HEA
A
B2
B2
B2
A 2.60E-02 HEA
A 2.30E+02 CAG
B2
C
B2 6.10E+00 HEA
B2
D
B2
C
Bl 4.86E+00 CAG
B2
A 9.30E-HD3 CAG
B2
D
6 . 10E+00 HEA
B2
B2
B2
B2
4.10E+01 HEA
B2
Bl
B2
B2
B2
-------
C-2S
OSWER Directive 9*53.00-2
Date Prepared: October 1. 1986
EXHIBIT C-4
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- RISK CHARACTERIZATION
Chemical Name
Diallate
Diaroinotoluene (mixed)
1,2,7,8-Dibenzopyrene -
Dibenz(a,h)anthracene
l,2-Dibromo-3-chloropropane
Dibutylnitrosaraine
3,3'-Dichlorobenzidine
1,2-Dichloroethane (EDC)
1,1-Dichloroethylene
Dichlorotne thane
Dieldrin
Diepoxybutane
Diethanolnitrosamine
Diethyl Arsine
1,2-Diethylhydrazine
Diethylnitrosamine
Diethylstilbestrol (DES)
Dihydrosafrole
3,3' -Diraethoxybenzidine
Dimethyl Sulfate
Dimethylaminoazobenzene
7 ,12-Diaiethy Iber.zf a ) anthracene
3,3' -Dimethylbenzidene
Dimethylcarbamoyl Chloride
1,1-DimethyIhydrazine
1,2-Dime thyIhydrazine
DimethyInitrosamine
Dinitrotoluene (mixed;
1,4-Dinitrotoluene
2,6-Dinitrotoluene
1,4-Dioxane
1,2-DiphenyIhydrazine
DipropyInitrosamine
Epichlorohydrin
Ethyl-4,4'-dichlorobenzilate
Ethylene Dibromide (EDB)
Oral Route
Inhalation Route
Potency
Factor
(?F)
Cmg/kg/d)-l
5
1
9
5
7
3
4
2
3
7
9
4
.4QE+00
./OE-t-00
. 10E-02
.80E-01
.50E-03
.OOE-t-01
.40E+01
.60E+01
. 10E-01
. 70E-01
.90E-04
.10E-KH
EPA _' Potency EPA
Weight Factor Weight
of . (?F) of
Source*j Evidence ("mg/kg/d)-l Source2- Evidence.
CAG
CAG
HEA
HEA
HEA
CAG
CAG
CAG
CAG
CAG
CAG
CAG
C
B2
B2
B2
B2
B2
82
B2 3.50E-02 HEA
C 1.16E-MDO HEA
B2 1.43E-02 HEA
B2
82
82
D
B2
B2
A
B2
B2
82
82
82
32
82
82
B2
82
B2
82
C
82
81
82
82
B2
B2
BI
32
B2
B2
B2
32
32
32
C
32
32
BT
u ^
32
" ' D
32
32
A
32
31
32
" "^
w .
51
3;
32
32
C
"*
32
C
32
32
32
32
32
32
-------
C-26
OSVER Directive 9i83.00-2
Date Prepared: October 1. 1986
EXHIBIT C-4
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Name
Potency EPA
Factor Weight
(PF) ' of
(mg/kg/d)-l Source*J Evidence
Potency EPA
Factor Weigh"
(PF) of
("mg/kg/d)-l Source2- Eviden
Ethylene Oxide
Ethylenethiourea
Ethyl Methanesulfonate
1-Ethyl-nitrosourea
Formaldehyde
Glycidaldehyde
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorobutadiene
alpha-Hexachlorocyclohexane (HCCH)
beta-HCCH
garama-HCCH (Lindane)
Hexachloroethane
Hydrazine
IndenoC1,2,3-cd)pyrene
lodomethane
Isosafrole
Kepone
Lasiocarpine
Melphalan
Methyl Chloride
3-MethyIcholanthrene
i ,* ' -Methy lene-bis -2-chioroaniline
Methylnitrosourea
Methylnitrosourethane
Methyl-thiouracil
Methylvinylnitrosamine
N-Methyl-N1-nitro-N-nitrosoguanadine
Mitomycin C
1-Napthylamine
2-Napthy1amine
Nickel and Compounds
N-Nitrosopiperidine
N-Nitrosopyrrolidine
5-Nitro-o-toluidine
3.
3.
2.
1.
7.
1.
1.
1.
1.
3.
.e
2.
30E+01
iOE+00
60E+00
69E+00
73E-03
10E+01
80E+00
33E*00
40E-02
OOE+02
NA
10E+00
CAG
CAG
CAG
HEA
HEA
CAG
CAG
HEA
CAG
CAG
CAG
B1/B2 3.50E-01 CAG
B2
B2
'B2
82
B2
B2
B2
B2
C
B2
C
B2/C
C
B2
C
C
B2
B2
B2
Bl
C
32
B2
B2
B2
B2
B2
B2
B2
C
A
A 1.19E+00 HEA
B2
B2
C
Bl/E
I
I
I
I
B2
-------
C-27
OSWER Directive 9483.00-2
Date Prepared: October 1. 1986
EXHIBIT C-4
(Continued)
TOXICITY DATA FOR POTENTIAL CARCINOGENIC EFFECTS
-- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Name
Pentachloronitrobenzene
Pentachlorophenol
Phenacetin
Polychlorinated Biphenyls (PCSs)
Polynuclear Aromatic Hydrocarbons
Propane Sultone
1,2-Propylenimine
Saccharin
Safrole
Streptozocin
2,3,7,8-TCDD (Dioxin)
1,1,1,2-Tetrachloroethane
1,1,2,2-Tetrachloroethane
Tetrachloroethylene
Thioacetamide
Thiourea
o-Toluidina' hydrochloride
Toxaphene
1,1,2-Trichloroethane
Trichloroethylene
2 ,4, 6-Trichlorophenol
Tris(2,3-dibromopropy1)phosphate
Trypan Blue
Uracil Mustard
Urethane
Vinyl Chloride
Potency
Factor
fmg/kg/d)-l
EPA
Weight -
of -
Source2' Evidence
Potency
Factor
(PF)
(mg/kg/d)-l
EPA
Source
2-
of-
Evidence
1.15E-MD1
1.56E-t-05
2.00E-01
5.10E-02
1. lOE-i-00
5.73E-02
1. 10E-02
1.98E-02
2.30E+00
HEA
HEA
HEA
HEA
HEA
CAG
HEA
HEA
HEA
HEA
C
D
82
B2
82
82
C
82
82
82
82
C
82
82
82
82
82
C
82
82
82
32
82
32
A
6.11E-MDO
HEA
1.70E-03
HEA
4.60E-03
HEA
C
D
82
- - B2
32
82
C
82
82
B2
C
C
32
32
82
B2
82
C
32
E2
2 1
2 50E-02
HEA
lj The list of chemicals presented in this exhibit is based on EPA's Reportable Quantities
Analysis and should not be considered an all-inclusive list of suspected carcinogens. Refer
to Exhibit C-3 for toxicity constants for indicator selection for the chemicals listed here.
IJ Sources for Exhibit C-4:
HEA = Health Effects Assessment, prepared by the Environmental Criteria and
Assessment Office, U.S. EPA, Cincinnati, Ohio, 1985 (updated in May 1986).
CAG = Evaluation by Carcinogen Assessment Group, U.S. EPA, Washington, D.C., 1985.
-------
OSVER Directive 9*83.00t2
C-28
EXHIBIT C-5
Date Prepared: October 1. I
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY l-
Oral Route
r.outa
Chemical Name
Acenaphthene 3
Acenaphthylene @
Acetone
Acetonitrile
2-Acetylaminofluorene 3
Acrylic Acid
Acrylonitrile 3
Aflatoxin Bl 3
Aldicarb
Aldrin 3
Allyl Alcohol
Aluminum Phosphide
4-Aminobiphenyl 3
Amitrole 3
Ammonia
Anthracene (§
Antimony and Compounds
Arsenic and Compounds 3
Asbestos 3
Auramine 3
Azaserine 3
Aziridine 3
Barium and Compounds
Benefin
Benzene 3
Benzidine 3
3enz(a)anthracene 3
Benz(c)acridine 3
Benzo(a)pyrene 3
Benzo(b)fluoranthene 3
Benzo(ghi)perylene 3
Benzo(k)fluoranthene 3
Benzotrichloride 3
Benzyl Chloride 3
Beryllium and Compounds 3
1,1-Biphenyl
Bis(2-chloroethyl)ether 3
Bis(2-chloroisopropyl)ether
Bis(chloromethyl)ether 3
Bis(2-ethylhexyl)phthalate (DEHP)
Brofflomethane
Minimum
Effective
Dose
(MED)
mg/day
2.
3.
8.
4.
1.
4.
3.
2 .
99E+01
80E-01
60E-KIO
OOE-MDO
90E-HDO
55E-01
2-.E-H31
Toxicity
Water
(win)
RVe 1/mg
9 6.02E-01
6 3.39E+00
3 6.82E+00
10 4.35E+00
9 1.80E+01
10 4.0SE-K30
5 1.17E-01
8 7.14E-01
Constant
Soil
-"(sin)
kg/mg
3.01E-05
1.69E-04
3.41E-04
2. 17E-04
9.00E-04
2.04E-04
5 .S5E-06
3.57E-05
Minimum
Effective
Dose
(MED)
mg/day RVe
1.23E-K12 -8
4.34E+01 10
3,^ .
4.25E+01 5
7.00E-01 8
l.OOE+00 * 9
2.70E-02 10
4.90E-KJO * 10
1.70E-rOO 10
1.19E-*-01 7
A
Tox
Con
(-a
i.:
*.,
3.
2
i
1
'
4
:
1
6.00E-01
2.67E-»-01 1.33E-03 6.2SE^OO
7.43E+02 10 2.69E-02 1.35E-06
1.10E-02
'.43E+02 * 10
-------
OSVER Directive 9433.00-2
C-29
EXHIBIT C-5
(Continued)
Date Prepared: October 1, I9S6
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Route
Chemical Name
Bromoxynil Octanoate
1,3-Butadiene
n-Butanol
Bucylphthalyl Butylglycolate
Cacodylic Acid i§
Cadmium and Compounds (?
Captan
Carbaryl
Carbon Disulfide
Carbon Tetrachloride (§
Chlordane @
Chlorobenzene
Chlorobenzilate @
Chlorodibromotne thane
Chloroform @
Chloromethyl Methyl Ether @
4-Chloro-o-toluidine Hydrochlondei?
Chromium III and Compounds
Chromium VI and Compounds §
Chrysene .?
Copper and Compounds
Creosote 5
Cresol
Crotonaide'nyde
Cyanides (n.o.s.) Jj
-- Barium Cyanide
-- Calcium Cyanide
-- Cyanogen
-- Cyanogen Chloride
-- Copper Cyanide
-- Hydrogen Cyanide
-- Nickel Cyanide
-- Potassium Cyanide
-- Potassium Silver Cyanide
-- Silver Cyanide
-- Sodium Cyanide
- Zinc Cyanide
Cyclophosphamide @
Dalapon
ODD @
M in imum
Effective
Dose
(MID)
mg/day RVe
2.39E+00 4
4 49E*00 10
9.S5E-H32 10
3.30E-r01 * 7
6.30E-t-01 * 10
5.60E+01 4
6.60E-00 6
1. 401*01 5
1.34E+00 * 4
Toxicity Constant
Water Soil
(wTn) (sin)
1/mg kg/ nig
3.35E+00 1.67E-04
4.45E-K30 2.23E-04
2.03E-02 1.02E-06
4.24E-01 2.12E-05
3.17E-01 1.59E-05
1.43E-01 7.14E-06
1.82E-K30 9.09E-05
7 . 14E-01 3 .57E-Q5
5 . 97E-00 2 . 99E-0^
Minimum
Effective
Dose
(MED)
mg/day
2
4
9
3
6
7
6
5
6
L
1
.39E+00 *
.46E-01
.85E+02 *
.30E-I-01
.30E-HD1
. 18E*01
. 60E-»-00 *
.90E+00
.40E-HDO
.40E-01 ~
.34E^-00
RVe
4
8
10
j
10
1
6
7
8
5
^
Air
Toxic-ity
Constant
(aTn)
m3/kg
3
3
2
4
3
2
1
2
2
;
5
.35E+01
,59EJ-02
.03E-01
.24E-QO
. 17E*00
.79E-01
.S2E-01
.37E-01
. 50E-01
. 14E-00
_ 9 7£-r '
-------
OSWER Directive 9483.00-2
C-30
EXHIBIT C-5
(Continued)
Date Prepared: October 1. 19?
TOXICITY DATA FOR NONCARCINOGEN 1C EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Chemical Name
DDE @
DDT <§
Decabromodiphenyl Ether
Diallate @
2,4-Diaminotoluene (§
1,2 ,7 ,8-Dibenzopyrene (§
Dibenz(a,h)anthrace.ne 3
1,2-Dibromo-3-chloropropane (3
Dibutylnitrosamine @
Dibutyl Phthalate
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
3,3' -Dichlorobenzidine (3
Dlchlorodifluoromethane
1,1-Dichlcroethane
1,2-Dichloroethane CEDC) 5
1,1-Dichloroethylene (3
1,2-Dichloroethylene (cis)
1,2-Dichloroethylene (trans)
Dichloromethane (§
2.--Dichlorophenol
2,4-Dichlorophenoxyacetic
Acid (2,4-D)
4- (2,4-Dichlorophenoxy)butyric
Acid (2,4-DB)
Dichlorophenylarsine @
1,2-Dichloropropane
1,3-Dichloropropene
Dieldrin (§
Diepoxybutane (2
Diethanolnitrosamine @
Diethyl Arsine (§
1,2-Diethylhydrazine (§
Diethylnitrosamine @
Diethyl Phthalate
Diechylstilbestrol (DES) §
Dihydrosafrole @
Dimethoate
3,3 '-Dimethoxybenzidine (§
Inhalation Route
M in imum
Effective
Dose
I MED)
mg/day
Toxicity Constant
RVe
Water
(win)
1/mg
Soil
(sin)
Minimum
Effective
Dose
(MED)
1.29E-02
2.00E+02 10
6.00E-01 1
1.24E-01 6.20E-06 1.29E+02 * 8
l.OOE-01 5.00E-06
3.33E+00 1.67E-04
2.00E+02 10
3.24E+00 5
2.99E+04
2.67E-04 1.34E-08 2.99E-H54
Aii
Toxic
Consi
(air
mg/day RVe m3/l
4
1
1
1
5
1
3
1
1
2
1
. 20E+02
.54E+02
.54E+02
. 54E-K32
.42E+02 *
. 14E+03
. 77E+01
. 89E+02 *
. 89E-H32 *
. 18E+04
. 21E-K32
8
4
4
4
7
10
7
5
5
10
5
3.
5.
5.
5 .
2.
1.
3,
5 .
5 .
9
8.
81E-02
19E-02
19E-02
19E-02
,58E-02
, 76E-02
.71E-01
.29E-02
. 29E-02
. 20E-04
,:cE-02
1.
2.
2.
2.
1.
8.
1.
2.
2.
4 .
4.
90E-06
60E-06
60E-06
60E-06
29E-06
80E-07
86E-05
65E-06
65E-06
60E-C8
13E-06
4.
2.
2.
2.
5 .
1.
1.
1.
1.
2 .
1
20E+02
77E+02
77E+02
77E+02
42E-KJ2
45E+02
77E+01
89E+02
89E-t02
1SE-HD4
21E*C2
* 8
* 5
5
5
-
a
5
5
5
* 10
5
3
3
3
3
2
1
5
5
5
9
3
,3
. 6
. 6
. 6
5
.1
.6
. ^
. 2
^
V
3.
2.
-------
CSVER Directive 9483.00-2
C-31
Date Prepared: October 1. 19S6
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Roi:te
Toxicity Constant
Chemical Name
Diraethylamine
Dimethyl Sulfate @
Dimethyl Terephthalate
Dimethylaminoazobenzene @
7,12-Dimethylbenz(a)anthracene
3,3'-Dimethylbenzidine §
Dimethylcarbamoyl Chloride <2
1,1-Dimethylhydrazine ?
1,2-Dimethylhydrazine i§
Dimethylnitrosaraine (2
1,3-Dinitrobenzene
4,6-Dinitfo-o-cresol
2,4-Dinitrophenol
2,3-Dinitrotoluene @
2,4-Dinitrotoluene (?
2,5-Dinitrotoluene @
2,6-Dinitrotoluene @
3,4-Dinitrotoluene (?
Dinoseb
1,4-Dioxane §
S.N'-Diphenylamine 3
1,2-Diphenylhydrazine =
Dipropylnitrosamine §
Disuifocon
Zndosulf an
Epichlorohydrin §
Echanol
Ethyl Acetate
Ethyl Methanesulfonate (§
Ethylbenzene
Ethyl-4,41-dichlorobenzilate §
Ethyiene Dibromide (EDS) (§
Ethylene Oxide (?
Ethylenethiourea @
1-Ethyl-nitrosourea (§
Ethylphthalyl Ethyl Glycolate
Ferric Dextrau @
Jluoranthene (3
Fluorene (§
Fluorides
innaiation
Minimum
Effective
Dose
(MED)
mg/day
RVe
3.70E+01 * 6
Water
(win)
1/mg
Soil
(sTn)
Minimum
Effective
Dose
(MED)
mg/day RVe
Air
Constant
(aTn)
m3/kg
3.24E-01 1.62E-05 3.70E-K51
1
2
1
2
2
.35E+00
.45E+00
.40E+01
.05E-HJ1
.99E+01
6
8
3
9
9
8.89E+00 4.44E-04
6.53E-I-00 3.27E-04
1.14E+00 5.71E-05
1.35E+00 * 6
2.45E-H30 * 8
1.40E+01 * 8
8.78E-01 4.39E-05 2.05E+01 * 9
6.02E-01 3.01E-05 2.99E+01 * 9
5.98E^-01 10 3.34E-01 1.67E-05 5.98E-<-01 * 10
2.40E+04 10 8.33E-04 4.17E-08 2.40E-0^ * 10
7.24E+02 * 4 1.10E-02 5.52E-07 7.24E-K32 4
3.24E-t-00
6.53E-+-01
S.78E-rOO
6.02E-00
S.33I-;
i. IDE-::
8.01E+00
1.25E+00 6.24E-05
-------
OSWER Directive 9483.00-2
C-32
Date Prepared: October 1, 198
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral. Rouce
Toxicity Constant
Inhalation Route
Chemical Name
Minimum
Effective
Dose
(MED)
mg/day
RVe
Water
(win)
1/mg
Soil
(sin)
Minimum Air
Effective Toxic
Dose ConTt
(MED) (aTn
mg/day RVe m3/Vc
Fluridone
Formaldehyde
Formic Acid
Fur an
Glycidaldehyde @
Glycol Ethers (n.o.s.)
-- Diethylene Glycol, Monoethyl Ether
-- 2-Ethoxyethanol
-- Ethylene Glycol, Monobutyl Ether
-- 2-Methoxyethanol
-- Propylene Glycol, Monoethyl Ether
- Propylene Glycol, Monomethyl Ether
Heptachlor (?
Heptachlor Epoxide (3
Hexachlorobenzene £ 5.00E+01 10
Hexachlorobutadiene @
Hexachlorocyclopentadiene
alpha-Hexachlorocyclohexane (HCCHli?
beta-HCCH §
gamma-HCCH (Lindane) @
delta-HCCH 3
Hexachloroechane >§ i.SlE-HH 6
Kexachlorophene 2.99E-01 9
Hydrazine 5
Hydrogen Sulfide
Indenod , 2 , 3-cd)pyrene ?
lodomethane §
Iron and Compounds
Isobutanol
Isoprene 5.50E-K12 * 4
Isosafrole (2
Isophorone
Isopropalin
Kepone (?
Lasiocarpine (§
Lead and Compounds (Inorganic) 2.24E+01 10
Linuron
Malathion
Manganese and Compounds
Melphalan (?
l.OOE+00
1.401
4.00E-01 2.00E-OS 5.00E-M31 * 10 4.Of
6.62E-03 3.31E-07
6.02E-01 3.0IE-05
i.i9E-02 10
2.99E+01 * 9
1.45E-02 7.2/E-O"
5.50E+02
8.93E-01 4.46E-05 2.24E+01 * 10 8
-------
OSVER Directive 9453.00-2
C-33
EXHIBIT C-5
(Continued)
Date Prepared: October I. 1986
TOXICITY DATA FOR NONCARCINOGENIC EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inhalation Kouca
Chemical Name
Mercury and Compounds (Alkyl)
Mercury and Compounds (Inorganic)
Mercury Fulminate
Methanol
Methyl Chloride
Methyl Ethyl Ketone
Methyl Ethyl Ketone Peroxide
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl Parathion
2-Methyl-4-Chlorophenoxyacetic Acid
2(2-Methyl-4-Chlorophenoxy)
propionic Acid
3-Methylcholanthrene
-------
C-34
OSVER Directive 9483.00-2
Date Prepared: October I. I9g
EXHIBIT C-5
(Continued)
TOXICITY DATA FOR NONCARCINOGEN 1C EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Chemical Name
m-Phenylenediamine
Phenyl Mercuric Acetate
Phosphine
Polychlorinated Biphenyls (PCBs)
Propane Sultone @
Propylenimine <§
Pyrene (§
Pyridine
Saccharin @
Safrole i§
Selenium and Compounds (n.o.s.)
-- Selenious Acid
-- Selenourea
-- Thallium Selenite
Silver and Compounds
Sodium Diethyldithiocarbamate
Streptozocin (§
Strychnine
Styrene
1,2 ,<* ,5 -Tetrachlorobenzene
2,3,7,8-TCDD (Dioxin) ^
1,1,1,2-Tetrachloroethane 3
1,1,2,2-Tetrachloroethane §
Tetrachloroethy ler.e §
2,3, i,6-Tetrachlorophenol
2,3,5,6-Tetrach1oroteraphthalate
Acid (DCPA)
Tetraethyl Lead (§
Thallium and Compounds (n.o.s.)
- Thallium Acetate
-- Thallium Carbonate
-- Thallium Chloride
-- Thallium Nitrate
-- Thallic Oxide
-- Thallium Sulfate
Thioacetamide @
Thiourea @
o-Tolidine @
Toluene
o-Toluidine Hydrochloride (?
Minimum
Effective
Dose
(MED)
mg/day RVe
Toxicity Constant
Water
(win)
1/mg
Soil
(sTn)
kg/fflg
Minimum Air
Effective Toxic
Dose Const
(MED) (aTr
mg/day RVe m3/V
1.90E-01 10 1.05E-»-02 5.26E-03 1.90E-01 * 10 1.03
1.001-01 1 2.00E+01 l.OOE-03 l.OOE-01 * 1 2.0C
2.05E+01 1 9.76E-02 4.88E-06 2.05E+01 * 1 9.
2.20E~01
i.55E-01 2.27E-03
9.62E-03 4.S1E-07
1.50E*00 7.i8E-05
Z.20E+01
7.27E-03
1.07E-r01
3
10
8
l.iOE-03
'.l-Ei-03 3.57E-01 2.50E*00
2.69E+03 * 7 5.20E-03 2.60E-07 2.69E+03 7
-------
OSVER Directive 9483.00-2*
C-35
EXHIBIT C-5
(Continued)
Date Prepared: October 1. 1986
TOXICITY DATA FOR NONCARCINOGEN 1C EFFECTS
-- SELECTION OF INDICATOR CHEMICALS ONLY
Oral Route
Inriaiation Route
Chemical Name
Toxaphene @
Tribromomethane (Bromofonn)
1,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane @
Trichloroethylene @
Trichlorofon
Tnchlororaonof luoromethane
2,4,5-Tnchlorophenol 1.18E-HJ2
2,4,6-Trichlorophenol 3
2,4,5-Trichlorophenoxyacet ic Acid
1,2,3-Trichloropropane
1,1,2-Trichloro-l, 2,2-trifluoroethane
Tris(2,3-dibromopropyl)phosphate ?
Trinitrotoluene (TNT)
Trypan Blue i|
L'racil Mustard @
I'ranium and Compounds 1.7QE+00
Urethane (2
Vanadium and Compounds 1.4QE-K11
Vinyl Chloride x 2.2SE+02
Warfarin
o-Xylene
m-Xylene
p-Xylene
Xylenes (mixed)
Zinc and Compounds 1.50E-1-02
-- Zinc Phosphide
Zineb
Minimum
Effective
Dose
(MED)
6 ,
3.
5 ,
9,
4,
mg/day
.60E-K30
. 73E-01
.45E+03 *
, 50E-H30
.52E-*01
RVe
6
4
2
5
10
Toxicity
1
2
7
1
*»
Water
(wTn)
1/mg
.82E+00
.14E-01
.33E-0'4
.05E+00
.42E-01
Constant
9.
1.
3.
5 .
2.
Soil
(sin)
kg/mg-
09E-05
07E-05
67E-08
26E-05
21E-05
Minimum
Effective
Dose
(MED)
6,
1,
5,
t
4
mg/day
. 60E+00 *
. 32E-KI1
. 45E-MD3
. 70E-*-00
. 52E-HH -
RVe
6
1
2
4
10
Air
Toxic iiy
Constant
(aTr.)
rc3/kg
1.
1.
"
2.
4.
.82E-KI1
.SIE-^OO
.33E-03
,96E*01
2E4-00
1.02E-01 5.10E-06 1.18EA02
1
10
7.06E+00 3.53E-04 l./OE-^OO
1.43E-01 7.14E-06 l.iOE-t-01
8.77E-02 4.39E-06 2.28E-02
1
10
1.07E-01 5.23E-06 1.5CE-02
1.02E-QO
'.G6E-01
Potential carcinogenic effects also. See Exhibits C-3 and C-4.
MZD and RVe values marked with an asterisk are based on values for the other exposure
route.
1J Refer to Exhibit C-6 for toxicity data for risk characterization for the chemicals
listed here.
IJ N.O.S. = not otherwise specified.
-------
OSWER Directive 9483.00-2
C-36
EXHIBIT C-6
Date Prepared: October 1, 1986
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION l-
Oral Route
Acceotable Intake
Inhalation Route
Acceptable Intake
Chemical Name
Acenaphthene @
Acenaphthylene (§
Acetone
Acetonitrile
2-Acetylaminofluorene @
Acrylic Acid
Acrylonitrile ?
Aflatoxin Bl <§
Aldicarb
Aldrin @
Allyl Alcohol
Aluminum Phosphide
4-Arainobiphenyl @
Amitrole @
Ammonia
Anthracene <§
Antimony and Compounds
Arsenic and Compounds !?
Asbestos (9
Auramine (?
Azaserine (?
Aziridine ?
Barium and Compounds
Benefin
Benzene (?
Benzidine (?
Benz(a)anthracene 3
Benz(c)acridine 5
Benzo(a)pyrene §
Benzo(b) f luoranthene t?
Benzo(ghi)perylene 3
Benzo(k) f luoranthene <§
Benzotrichloride (§
Benzyl Chloride (§
Beryllium and Compounds (§
1,1-Biphenyl
Bis(2-chloroethyl)ether (§
Bis(2-chloroisopropyl)ether
Bis(chloromethyl)ether @
Bis(2-ethylhexyl)phthalate (DEHP)
Bromomathane
Bromoxynil Octanoate
1,3-Butadiene
Subchron Chronic S_ubchron Chronic
(AIS) (AIC) -'(AIS) (AIC)
--mg/kg/day-- Source2-1 --mg/kg/day-- Source2-
l.OOE-01
8.00E-02
l.OOE-02
3.00E-05
5.00E-03
i.OOE-04
4.00E-04
5.1QE-Q2
3 OOE-01
5.00E-04
5.00E-02
2.00E-02
4.00E-04
3.00E-02
RfD 3.00E+01 3.00E+00
RfDJJ
RfD
RfD
RfD
RfD
RfD
HEA
HEA L.4'E-3("nu- 1.40E-04 HZ A
RfD
RfD
RfD
RfD
RfD
RfD
-------
OSVER Directive 9483.00-2'-
C-37
Date Prepared: October I. 1986
EXHIBIT C-6
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Oral Route Inhalation
Chemical Name
n-Butanol
Butylpthalyl Butylglycolate
Cacodylic Acid @
Cadmium and Compounds ?
Captan
Carbaryl
Carbon Disulfide
Carbon Tetrachloride (?
Chlordane @
Chlorobenzene I
Chlorobenzilate @
Chlorodibromoraethane
Chloroform (§
Chloromethyl Methyl Ether @
4-Chloro-o-toluidine Hydrochloride^
Chromium III and Compounds
Chromium VI and Compounds (?
Chrysene (3
Copper and Compounds
Creosote @
Cresol
Crotonaldehyde
Cyanides (n.o.s.) *-
-- Barium Cyanide
-- Calcium Cyanide
-- Cyanogen
-- Cyanogen Chloride
-- Copper Cyanide
-- Hydrogen Cyanide
-- Nickel Cyanide
Potassium Cyanide
-- Potassium Silver Cyanide
-- Silver Cyanide
-- Sodium Cyanide
-- Zinc Cyanide
Cyclophosphanide @
Dalapon
DDD @
DDE @
DDT @
Decabromodiphenyl Ether
Diallate @
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day--
Source
Acceptable Intake
Jubchron Chronic
(AIS) (AIC)
-Jmg/kg/day--. Source
1
1
1
2
1
1
5
. 70E-01 2
.OOE-01
.OOE+00
.OOE-02
.9QE-OU
.OOE-01
.OOE-01
.OOE-05
.70E-02
RfD
RfD
RfD
HZA
RfD
RfD
RfD
HEA 5.30E-02 5.70E-Q3 KEA
1.OOE-02
RfD
l.^OE+01
2.50E-02
3.70E-02
1.
5.
3
5
1
^
/
t4
i
5 .
7,
2
2,
5.
2
1,
U
5,
a,
5
1
.OOE+00
.OOE-03
. 70E-02
.OOE-02
.OOE-02
.OOE-02
.OOE-02
.OOE-02
.OOE-02
.OOE-02
.OOE-02
.OOE-02
.OOE-02
, OOE-02
.OOE-01
.OOE-01
.OOE-02
.OOE-02
.OOE-02
. OOE-04
.OOE-02
RfD
HEA
HEA
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
5.10E-03
1.OOE-02
1.OOE-01
HEA
HEA
HZA
-------
CSVER Directive 9483.00-3-
C-38
Date Prepared: October 1. 19S6
EXHIBIT C-6
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Oral Route Inhalation Route
Acceptable Intake Acceptable Intake
Subchron Chronic Subchron Chronic
(AIS) (AIC) (AIS) (AIC)
Chemical Name --mg/kg/day-- Source --.mg/kg/day- Source
2,4-Diarainotoluene @
1,2, 7 ,8-Dibenzopyrene @
Dibenz(a,h)anthracene @
1,2-Dibromo-3-chloropropane (?
Dibutylnitrosamine (2
Dibutyl Phthalate l.OOE-01 RfD
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
3,3'-Dichlorobenzidine @
Dichlorodifluoromethane 2.00E-01 RfD
1,1-Dichloroethane 1.20E+00 1.20E-01 HEA I.38E+00 1.38E-01 HEA
. 1,2-Dichloroethane (EDC) (§
1,1-Dichloroethylene @ 9.00E-03 RfD
1,2-Dichloroethylene (cis)
1,2-Dichloroethylene (trans)
Dichlororaethane @ 6.00E-02 RfD
2,4-Dichlorophenol 3.00E-03 RfD
2,4-Dichlorophenoxyacetic
Acid (2,4-D)
4- (2 ,4-Dichlorophenoxy)butyric
Acid (2,4-DB) ' 8.00E-03 RfD
Dichlorophenylarsine 3
1,2-Dichloropropane
1,3-Dichlorcpropene
Dieldrin (?
Diepoxybutane §
Diethanolnitrosaaiine 3
Diethyl Arsine (§
1,2-Diethylhydrazine (?
Diethylnitrosamine (§
Diethyl Phthalate 1.30E---01 RfD
Diethylstilbestrol (DES) (3
Dihydrosafrole <3
Dimethoate 2.00E-02 RfD
3,3'-Dimethoxybenzidine @
Dimethylamine
Dimethyl Sulfate @
Dimethyl Terephthalate l.OOE-01 RfD
Dimethylaminoazobenzene (3
7,12-Dimethylbenz(a)anthracene (§
3,3'-Dimethylbenzidine @
-------
OSWER Directive 9-83.00-2
C-39
Date Prepared: October I. 1986
EXHIBIT C-S
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZAT-ION
Chemical Name
Dimethylcarbamoyl Chloride (§
1,1-Dimethylhydrazine @
1,2-Dimechylhydrazine ?
Dimethylnitrosamine (§
1,3-Dinitrobenzene
^,6-Dinitro-o-cresol
2,^-Dinitrophenol
2,3-Dinitrotoluene (?
2,^-Dinitrotoluene i§
2,5-Dinitrotoluene (§
2,6-Dinitrotoluene @
3,i-Dinitrotoluene §
Dinoseb
1,4-Dioxane (?
N.N-Diphenylamine (?
1,2-Diphenylhydrazi.ne ?
Dipropylnicrosamine '5
Disulfocon
Endosulfan
Epichiorohydrin 5
Echanol
Eihyl Acecace
Echyl Mechanesulfonare 2
E'hylbenzene
Ethyl-'*. ,i ' -dichlorobenzilate
E'hylene Dibrotnide (EC3) §
Ethylene Oxide 5
Echylenechiourea 3
1-Ethyl-nicrosourea (3
Erhylphchalyl Echyl Glycolace
Ferric Dextran ?
Fluoranchene §
Fluorene @
Fluorides
Fluridone
Formaldehyde
Formic Acid
Furan
Glycidaldehyde (§
Glycol Ethers (n.o.s.)
-- Diethylene Glycol,
Monoethyl Ether
Oral Houce
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
Inhalation Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
'--mg/kg/day-- Source
2.00E-03
l.OOE-03
4..00E-03
1.50E-05
2.00E-03
9.00E-01
9.70E-01 l.OOE-01
3.00E+00
6.00E-02
8.00E-02
2.00E+00
l.OOE-03
5.00E-KJO 2.00E+00
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
HEA
-------
OSWER Directive 94S3.0G-2
C-40
EXHIBIT C-6
(Continued)
Date Prepared: October 1. 1986
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Chemical Name
Oral Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day- Source
Inhalation Route
Acceptable Intake
"Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
4.7E-KT) 3.60E-01
-- 2-Ethoxyethanol
-- Ethylene Glycol,
Monobutyl Ether
-- 2-Methoxyethanol
-- Propylene Glycol,
Monoethyl Ether
-- Propylene Glycol,
Monomethyl Ether
Heptachlor @
Heptachlor Epoxide @
Hexachlorobenzene.(?
Hexachlorobutadiene @
Hexachlorocyclopentadiene
alpha-Hexachlorocyclohexane (HCCH)@
beta-HCCH @
gamma-HCCH (Lindane) @
delta-HCCH @
Hexachloroethane @
Hexachlorophene
Hydrazine (3
Hydrogen Sulfide
Indenod ,2 , 3-cd)pyrene ?
lodomethane {?
Iron and Compounds
Isobutanol
Isoprene
Isosafrole §
Isophorone
Isopropalin
Kepone (2
Lasiocarpine (§
Lead and Compounds (Inorganic)
Linuron
Malathion
Manganese and Compounds
Melphalan @
Mercury and Compounds (Alkyl)
Mercury and Compounds (Inorganic) 2.00E-03 2.00E-03
Mercury Fulminate 3.00E-03
Methane1 5.00E-01
Methyl Chloride
Methyl Ethyl Ketone 5.00E-02
6.3GE-HDO 6.30E-01
6.SOE-1-00 6.80E-01
3.00E-05
2.00E-03
7.00E-02 7.00E-03
3.00E-04
3.00E-03
3.00E-01
2.00E-01
3.00E-02
1.40E-03
2.00E-02
5.30E-01 2.20E-01
2.80E-04 3.00E-04
HEA
HEA
HEA
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
HEA
RfD
HEA
RfD
RfD
RfD
RfD
6.9E-2(T) 5.00E-02
1.60E-01 1.60E-02
5.9E-2(T) 2.40E-02
4.90E+00 4.90E-01
2.90E-03 6.60E-05
8.60E-C3
4.30E-04
3.00E-04 3.00E-04
l.OOE-04 l.OOE-04
5.10E-04 5.10E-05
HEA
HEA
HEA
HEA
HEA
HEA
RfD 2.20E+00 2.20E-01
HEA
HEA
HEA
HEA
HEA
-------
OSVER Directive 94S3.0Q-2-
C-41
Date Prepared: October 1. 1986
EXHIBIT C-6
(Continued)
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Oral Route
Inhalation Route
Chemical Name
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day-- Source
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day- Source
Methyl Ethyl Ketone Perioxide
Methyl Isobutyl Ketone
Methyl Methacrylate
Methyl Parathion
2-Methyl-4-Chlorophenoxyacetic Acid
ZCZ-Methyl-^-Chlorophenoxy)
propionic Acid
3-Methylcholanthrene !?
4,4* -Methylene-bis-2-chloroaniline
-------
OSWER Directive 9483.00-2
C-42
Date Prepared: October 1, 1986
EXHIBIT C-6
(Continued)
TOXICITY DATA FOR NONCARGINOGEN 1C
EFFECTS -- RISK CHARACTERIZATION
Chemical Name
Saccharin @
Safrole @
Selenium and Compounds (n.o.s.)
- Selenious Acid
-- Selenourea
-- Thallium Selenite
Silver and Compounds
Sodium Diethyldithiocarbamate
Streptozocin @
Strychnine
Styrene
1,2,4,5-Tetrachlorobenzene
2,3,7,8-tCDD (Dioxin) <§
1,1,1,2-Tetrachloroethane @
1,1,2,2-Tetrachloroethane @
Tetrachloroethylene @
2,3,4,6-Tetrachlorophenol
2,3,5,6-Tetrachloroterephthalate
Acid (DCPA)
Tetraethyl Lead ?
Thallium and Compounds (n.o.s.)
-- Thallium Aceta-e
-- Thallium Carbonate
-- Thallium Chloride
-- Thallium Nitrate
-- Thallic Oxide
-- Thallium Sulfate
Thioacetaniide 2
Thiourea (3
o-Tolidine (2
Toluene
o-Toluidine Hydrochloride @
Toxaphene @
Tribromomethane (Bromoform)
1,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane @
Trichloroethylene @
Trichlorofon
Trichloromonofluoromethane
2,4,5-Trichloropheno1
2 ,4,6-Trichlorophenol @
Oral Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--tng/kg/day-- Source
Inhalation Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
-*mg/kg/day-- Source
3.20E-03 3.00E-03 HEA
3.00E-03 RfD
5.00E-03 RfD
5.00E-04 RfD
3.00E-03 RfD
3.00E-02 RfD
3.00E-04 RfD
2.00E-01 RfD
3.00E-04 RfD
2.00E-02 RfD
l.OOE-02 RfD
4.30E-01 3.00E-01
2.00E-02
5.40E-01
3.00E-01
l.OOE+00 l.OOE-01
l.OOE-03
HZA
5,
1.
4» ,
5
^
5
5
i* .
5
.OOE-02
.OOE-07
.OOE-04
.OOE-04
.OOE-04
.OOE-04
.OOE-04
.OOE-04
.OOE-04
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD
RfD 1.50E-H30 1.50E-rOO
RfD
HEA
RfD
RfD
1.10E+01 6.30E-*-00
HEA
HZA
-------
C-43
EXHIBIT C-6
(Continued)
OSVZR Directive 9483.00-2
Date Prepared: October 1, 1986
TOXICITY DATA FOR NONCARCINOGENIC
EFFECTS -- RISK CHARACTERIZATION
Chemical Name
2,4,5-Trichlorophenoxyacetic Acid
1,2,3-Trichloropropane
l,l,2-Trichloro-l,2,2-
Trifluoroethane
Tris(2,3-dibroraopropyl)phosphate (3
Trinitrotoluene (TNT)
Trypan Slue (2
Uracil Mustard @
Uranium and Compounds
I'rethane (3
Vanadium and Compounds
Vinyl Chloride @
Warfarin
o-Xylene
m-Xylene
p-Xylene
Xylenes (mixed)
Zinc and Compounds
-- Zinc Phosphide
Zineb
Oral Route
Acceptable Intake
Subchron Chronic
(AIS) (AIC)
--mg/kg/day--
Source
Inhalation Route
Acceptable Intake
Subchron Chronic
-(AIS) (AIC)
--rag/kg/day- Source
3.00E-02
l.OOE-01
3.00E-KU
2.00E-04
RfD
RfD
RfD
RfD
2.00E-02 RfD
3.00E-04 RfD
l.OOE-01 l.OOE-02 HEA
l.OOE-01 l.OOE-02 HEA
l.OOE-01 l.OOE-02 HEA
2.10E-01 2.10E-01 HEA
3.00E-04 RfD
5.00E-02 RfD
9.6E-KT) 2.00E-01. HEA
l.OOE+00 2.00E-01 HEA
6.9E-UT) 4.00E-01 HEA
l.OOE-01 l.OOE-02 HEA
5 Potential carcinogenic effects also. See Exhibits C-3 and C-4.
l- Refer to Exhibit C-5 for toxicity data for indicator selection for the
chemicals listed here.
2- Sources for Exhibit C-6:
RfD = Agency-wide reference dose value, developed by an inter-office work group
chaired by the Office of Research and Development, U.S. EPA, Washington, D.C.,
1986.
HEA = Health Effects Assessment document, prepared by the Environmental Criteria
and Assessment Office, U.S. EPA, Cincinnati, Ohio, 1985 (updated in May 1986).
lj The RfD values listed here are EPA-verified numbers. All RfD values were
derived based on oral exposure; however, in the absence of other more specific data,
these values may also be useful in assessing risks of inhalation exposure.
*J T indicates that teratogenic or fetotoxic effects are the basis for the AIS
value listed.
Sj N.O.S. = not otherwise specified.
-------
OSWER Directive 9483.00-2
C-44
EXHIBIT C-7
CHEMICALS AND CHEMICAL GROUPS HAVING 'EPA HEALTH
EFFECTS ASSESSMENT (HEA) DOCUMENTS ^
CHEMICAL
NTIS2J PB NUMBER
Acetone
Arsenic and Compounds
Asbestos
Barium and Compounds
Benzene
Benzo(a)pyrene
Cadmium and Compounds
Carbon Tetrachloride
Chlordane
Chlorobenzene
Chloroform
Chromium III and Compounds
Chromium VI and Compounds
Coal Tars
Copper and Compounds
Cresol
Cyanides
DDT
1 , 1-Dichloroethane
1 , 2-Dichloroethane (EDC)
1 , 1-Dichloroethylene
1 ,2-cis-Dichloroethylene
1 , 2 -trans -Dichloroethylene
Dichlorome thane
Ethylbenzene
Glycol Ethers
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
gamma-Hexachlorocyclohexane (Lindane)
Iron and Compounds
Lead and Compounds (Inorganic)
Manganese and Compounds
Mercury
Methyl Ethyl Ketone
Naphthalene
Nickel and Compounds
Pentachlorophenol
Phenanthrene
Phenol
Polychlorinated Biphenyls (PCBs)
86 134277/AS
86 134319/AS
86 134608/AS
86 134327/AS
86 134483/AS
86 134335/AS
86 134491/AS
86 134509/AS
86 134343/AS
86 134517/AS
86 134210/AS
86 134467/AS
86 134301/AS
86 134350/AS
86 134368/AS
86 134616/AS
86 134228/AS
86 134376/AS
86 134384/AS
86 134137/AS
86 134624/AS
86 134269/AS
86 134525/AS
86 134392/AS
86 134194/AS
86 134632/AS
86 134285/AS
86 134640/AS
86 134129/AS
86 134673/AS
86 134657/AS
86 134665/AS
86 134681/AS
86 134533/AS
86 134145/AS
86 13425 I/AS
86 134293/AS
86 134541/AS
86 134400/AS
86 134186/AS
86 134152/AS
-------
OSWER Directive 9483.00-2
C-45
EXHIBIT C-7
(Continued)
CHEMICALS AND CHEMICAL GROUPS HAVING EPA HEALTH
EFFECTS ASSESSMENT (HEA) DOCUMENTS 1J
CHEMICAL
NTIS2J PB NUMBER
Polynuclear Aromatic Hydrocarbons
Pyrene
Selenium and Compounds
Sodium Cyanide
Sulfuric Acid
2,3,7,8-TCDD (Dioxin)
1,1,2,2-Tetrachloroethane
Tetrachloroethylene
Toluene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Vinyl Chloride
Xylene
Zinc and Compounds
Complete Set of 58 HEAs
86 134244/AS
86 134418/AS
86 134699/AS
86 134236/AS
86 134426/AS
86 134558/AS
86 134434/AS
86 134202/AS
86 134442/AS
86 134160/AS
86 134566/AS
86 134574/AS
86 134459/AS
86 134582/AS
86 134475/AS
86 134178/AS
86 134590/AS
86 134111/AS
l- As of the date of publication for this manual.
2- National Technical Information Service.
-------
OSWER Directive 9483.00-2
C-46
EXHIBIT C-8
SAFE DRINKING WATER ACT
MAXIMUM CONTAMINANT LEVELS (MCLs) a/
CONCENTRATION
CHEMICAL (mg/1)
Arsenic 0.05
Barium 1.0
Cadmium 0.01
Chlorophenoxys
2,4-Dichlorophenoxyacetic
acid (2,4-D) 0.1
2,4,5-Trichlorophenoxy-propionic 0.01
acid (2,4,5-TP)
Chromium VI (hexavalent) 0.05
Endrin 0.0002
Fluoride 1.4-2.4
Lindane (99% gamraa-HCCH) . 0.004
Lead 0.05
Mercury 0.002
Methoxychlor 0.1
Nitrate (as N) 10.0
Radionuclides
Radiura-226 and 228 5 pCi/1
Gross alpha activity 15 pCi/1
Tritium 20,000 pCi/1
Strontium-90 8 pCi/1
Other man-made radionuclides b/
Selenium 0.01
Silver 0.05
Toxaphene 0.005
Trihalomethanes (total) c/ 0.1
a/ EPA has also proposed MCLs for eight volatile organic chemicals:
trichloroethylene, carbon tetrachloride, 1,1,1-trichloroethane, vinyl
chloride, 1,2-dichloroethane, benzene, 1,1-dichloroethylene, and
p-dichlorobenzene (50 Federal Register 46902-46933, November 13, 1985).
b/ Radionuclides in drinking water are limited to activity levels
corresponding to a total body or any internal organ dose of 4 millirem/year,
summed over all radionuclides present.
c/ Total trihalomethanes refers to the sum concentration of chloroform,
bromodichloromethane, dibromochloromethane, and bromoform.
-------
OSWER Directive 9483.00-2
C-47
EXHIBIT C-9
SAFE DRINKING WATER ACT MAXIMUM
CONTAMINANT LEVEL GOALS (MCLGs) a/
CONCENTRATION
CHEMICAL (mg/1)
Benzene 0
Carbon tetrachloride 0
p-Dichlorobenzene 0.75
1,2-Dichloroethane 0
1,1-Dichloroethylene 0.007
1,1,1-Trichloroethane 0.2
Trichloroethylene 0
Vinyl chloride 0
a/ EPA has also proposed MCLGs for 40 additional
chemicals.
-------
OSWER Directive 9483.00
C-48
EXHIBIT C-10
EPA AMBIENT WATER QUALITY CRITERIA
(WQC) FOR PROTECTION OF HUMAN HEALTH
CHEMICAL
CONCENTRATON a/
Aquatic Organisms
and Drinking Water.
Adjusted for Drinking
Water Only b/ -
Acenaphthene
Acrolein
Acrylonitrile*
Aldrin*
Antimony*
Arsenic*
Asbestos
Benzene*
Benzidine*
Beryllium*
Cadmium-"
Carbon tetrachloride*
Chlordane*
Chlorinated benzenes
Hexachlorobenzene*
1,2,4,5-Tetrachlorobenzene"
Pent ach lor obenzene ''"
Trichlorobenzene*
Nonochlorobenzene*
Chlorinated ethanes
1,2-Dichloroethane'-
1,1,1-Trichloroethane-
1,1,2-Trichloroechane-
1,1,2,2-Tetrachloroethane-
Hexachloroethane-
Monochloroethane
1,1-Dichloroethane-
1,1,1,2-Tetrachloroethane
Pentachloroethane
Chlorinated naphthalenes
Chlorinated phenols
3-Monochlorophenol
'4 -Monoch loropheno 1
2,3-Dichloropheno1
2,5-Dichlorophenol
2,6-Dichloropheno1
3,4-Dichlorophenol
2,3,4,6-Tetrachlorophenol*
2,4,5-Trichloropheno1*
20 ug/1 (Organoleptic)
320 ug/1
0 (58 ng/1)
0 (0.074 ng/1)
146 ug/1
0 (2.2 ng/1)
0 (30,000 fibers/1)
0 (0.66 ug/1)
0 (0.12 ng/1)
0 (3.7 ng/1)
10 ug/1
0 (0.4 ug/1)
0 (0.46 ng/1)
0 (0.72 ng/1)
38 ug/1
74 ug/1
Insufficient data
488 ug/1
0 (0.94 ug/1)
18.4 mg/1
0 (0.6 ug/1)
0 (0. 17 ug/1)
0 (1.9 ug/1)
Insufficient data
Insufficient data
Insufficient data
Insufficient data
Insufficient data
c'/ 20 ug/1 (Organoleptic
540 ug/1
0 (63 ng/1)
0 (1.2 ng/1)
146 ug/1
(25 ng/1)
(30,000 fibers/1)
0 (0.67 ug/1)
0 (0.15 ng/1)
0 (3.9 ng/1)
10 ug/1
0 (0.42 ug/1)
0 (22 ng/1)
0 (21 ng/1)
180 ug/1
570 ug/1
Insufficient data
488 ug/1
0 (0.94 ug/1)
19 mg/1
0 (0.6 ug/1)
0 (0.17 ug/1)
0 (2.4 ug/1)
Insufficient data
Insufficient data
Insufficient data
Insufficient data
Insufficient data
0.1 ug/1 (Organoleptic)
0.1 ug/1 (Organoleptic)
0.04 ug/1 (Organoleptic)
0.5 ug/1 (Organoleptic)
0.2 ug/1 (Organoleptic)
0.3 ug/1 (Organoleptic)
1.0 ug/1 (Organoleptic)
2600 ug/1
0.1 ug/1 (Organolept
0.1 ug/1 (Organolept
0.04 ug/1 (Organolej
0.5 ug/1 (Organolepi
0.2 ug/1 (Organolepi
0.3 ug/1 (Organolep-
1.0 ug/1 (Organolep
2600 ug/1
-------
OSWER Directive 9483 ."00-2
C-49
EXHIBIT C-10
(Continued)
EPA AMBIENT WATER QUALITY CRITERIA
(WQC) FOR PROTECTION OF HUMAN HEALTH
CHEMICAL
CONCENTRATON a/
Aquatic Organisms
and Drinking Water"
Adjusted for Drinking
Water Only b/ ~
2,4,6-Trichlorophenol*
2-Methyl-4-chlorophenol
3-Methyl-4-chlorophenol
. 3-Methyl-6-chlorophenol
Chloroalkyl ethers
bis-(Chloromethyl) ether*
bis-(2-Chloroethyl) ether*
bis-(2-Chloroisopropyl) ether
Chloroform""
2-Chlorophenol
Chromium Cr+6*
Cr+3*
Copper*
Cyanide*
DDT*
'Dichlorobenzenes* (all isomers)
Dichlorobenzidines
Dichloroethylenes
1,1-Dichloroethylene*
1,2-Dichloroethylene
Dichloromethane*
2, 4-Dichloropheno !"''
Dichloropropanes/Dichloropropenes
Dichloropropanes
Dichloropropenes
Dieldrin*
2,4-D imethyIpheno1
2,4-Dinitrotoluene*
1,2-Diphenylhydrazine*
Endosulfan*
Endrin
Ethylbenzene*
Fluoranthene
Haloethers
Halomethanes
Heptachlor*
Hexachlorobutadiene*
Hexachlorocyclohexanes (HCCH)
alpha-HCCH*
0 (1.2 ug/1)
1800 ug/1 (Organoleptic)
3000 ug/1 (Organoleptic)
20 ug/1 (Organoleptic)
0 (0.0038 ng/1)
0 (30 ng/1)
34.7 ug/1
0 (0.19 ug/1)
0.1 ug/1 (Organoleptic)
50 ug/1
170 ng/1
1 mg/1 (Organoleptic)
200 ug/1
0 (0.024 ng/1)
400 ug/1
0 (10.3 ng/1)
0 (33 ng/1)
Insufficient data
See Halomethanes
3.09 mg/1
Insufficient data
87 ug/1
0 (0.071 ng/1)
400 ug/1 (Organoleptic)
0 (0.11 ug/1)
0 (42 ng/1)
74 ug/1
1 ug/1
1.4 rag/1
42 ug/1
Insufficient data
0 (0.19 ug/1)
0 (0.28 ng/1)
0 (0.45 ug/1)
0 (9.2 ng/1)
0 (1.8 ug/1)
1800 ug/1 (Organoleptic)
3000 ug/1 (Organoleptic)
20 ug/1 (Organoleptic)
0 (0.0039 ng/1)
0 (30 ng/1)
34.7 ug/1
0 (0.19 ug/1)
0.1 ug/1 (Organoleptic)
SO ug/1
179 mg/1
1 mg/1 (Organoleptic)
200 ug/1
0 (> 1.2 ng/1)
470 ug/1
0 (20.7 ng/1)
0 (33 ng/1)
Insufficient data
See Halomethanes
3.09 mg/1
Insufficient data
87 ug/1
0 (1.1 ng/1)
400 ug/1 (Organoleptic)
0 (0.11 ug/1)
0 (46 ng/1)
138 ug/1
1 ug/1
2.4 mg/1
188 ug/1
Insufficient data
0 (0.19 ug/1)
0 (11 ng/1)
0 (0.45 ug/1)
0 (13 ng/1)
-------
OSWER Directive 9483.00-
C-50
EXHIBIT C-10
(Continued)
EPA AMBIENT WATER QUALITY CRITERIA
(WQC) FOR PROTECTION OF HUMAN HEALTH
CHEMICAL
CONCEN'TRATON a/
Aquatic Organisms
and Drinking Water _"
Adjusted for Drinking
Water Only b/ j;
beta-HCCH*
gamma-HCCH*
delta-HCCH
epsilon-HCCH
Technical-HCCH
Hexachlorocyclopentadiene*
Isophorone*
Lead*
Mercury*
Naphthalene
Nickel*
Nitrobenzene*
N'itrophenols
2,4-Dinitro-o-cresol
Dinitrophenol*
Mononitrophenol
Trinitrophenol
Nitrosaraines
n-Nitrosodimethylamine*
n-N11rosodiethy 1amine*
n-Nitrosodi-n-butylamine*
n-Nitrosodiphenylamine
n-Nitrosopyrrolidine*
Pentachlorophenol*
Phenol*
Phthalate esters
Dimethylphthalate
DiethyIphthaiate*
Dibutylphthalate*
Di-2-ethylhexylphthalate*
Polychlorinated biphenyls (PCBs)*
Polynuclear aromatic hydrocarbons
(PAHs)*
Selenium*
Silver*
2,3,7,8-TCDD*
Tetrachloroethylene*
Thallium*
0 (16.3 ng/1)
0 (12.3 ng/1)
Insufficient data
Insufficient data
0 (5.2 ng/1)
206 ug/1
5.2 mg/1
50 ug/1
144 ng/1
Insufficent data
13.4 ug/1
19.8 mg/1
13.4 ug/1
70 ug/1
Insufficient data
Insufficient data
(1.4 ng/1)
(0.8 ng/1)
(6.4 ng/1)
(4.9 ug/1)
(16 ng/1)
.01 mg/1
3.5 mg/1
313 mg/1
350 mg/1
34 mg/1
15 mg/1
0 (0.079
ng/D
0 (2.8 ng/1)
10 ug/1
50 ug/1
0 (0.000013 ng/1)
0 (0.8 ug/1)
13 ug/1
0 (23.2 ng/1)
0 (17.4 ng/1)
Insufficient data
Insufficient data
0 (7.4 ng/1)
206 ug/1
5.2 mg/1
50 ug/1
10 ug/1
Insufficient data
15.4 ug/1
19.8 mg/1
13.6 ug/1
70 ug/1
Insufficient data
Insufficient data
(1.4 ng/1)
(0.8 ng/1)
(6.4 ng/1)
(7.0 ug/1)
(16 ng/1)
.01 mg/1
,5 mg/1
350 mg/1
434 mg/1
44 mg/1
21 mg/1
0 (> 12.6 ng/1)
0 (3.1 ng/1)
10 ug/1
50 ug/1
0 (0.00018 ng/1)
0 (0.88 ug/1)
17.8 ug/1
-------
OSWZR Directive 9483.00-2
C-51
EXHIBIT C-10 '
(Continued)
EPA AMBIENT WATER QUALITY CRITERIA
(WQC) FOR PROTECTION OF HUMAN HEALTH
CHEMICAL
CONCENTRATOR a/
Aquatic Organisms
and Drinking Water-"
Adjusted for Drinking_
Water Only b/
Toluene*
Toxaphene*
Trichloroethylene*
Vinyl chloride*
Zinc*
14.3 mg/1
0 (0.71 ng/1)
0 (2.7 ug/1)
0 (2.0 ug/1)
5 mg/1 (Organoleptic)
15 mg/1
0 (26 ng/1)
0 (2.8 ug/1)
0 (2.0 ug/1)
5 mg/1 (Organoleptic)
Toxicity values necessary for risk characterization are given in Appendix C.
a/ The criterion value is zero for all potential carcinogens. The
concentration value given in parentheses for potential carcinogens corresponds to a
risk of 10 , which is the midpoint of the range of 10 to 10 given in
water quality criteria documents. To obtain concentrations corresponding to risks
of 10 , the 10 concentrations should be multiplied by 10. To obtain
concentrations corresponding to risks of 10
be divided by 10.
-7
the 10 concentrations should
b/ These adjusted criteria, for drinking water ingestion only, were derived
from published EPA ambient water quality criteria (45 Federal Register 79318-79379,
November 23, 1980) for combined fish and drinking water ingestion and for fish
ingestion alone. The adjusted values are not official EPA ambient water quality
criteria, but may be appropriate for sites with potentially contaminated ground
water. In the derivation of these values, intake was assumed to be 2 liters/day
for drinking water and 6.5 grams/day for fish, and human body weight was assumed to
be 70 kilograms. Values for bioconcentration factor, carcinogenic potency, and
acceptable daily intake were those used for water quality criteria development.
c/ Criteria designated as Organoleptic are based on taste and odor effects,
not human health effects. Health-based water quality criteria are not available
for these chemicals.
-------
CXIIIUI T C-l 1
lien 1 ill Adv i sorics
CIIIMICAL
Aery 1 amide
Alachlor
Aid ica rb*
Arsenic*
Ba r i um"
Benzene"
Cadmium"
Ca rbofuran
Carbon Tetrachloride*
Chlordane*
Chlorobenzene*
Chromium*
Cyanide*
2,i)-D
0 i b romoch 1 o rop ropane
o-/m-Di chlorobenzene*
p-Oi chlorobenzene
1 ,2-Dichlo roe thane*
1 , 1-Dichloroethylene*
c i s-1 , 2-Dichloroethylene
t ran s-1 ,2-Oichloroethy len
Onn-day
10 kg
1500
15000
12
50
--
233
M3
50
1)000
63
1800
I'lOO
220
1100
200
8930
10700
7')0
1000
1)000
e 2720
loo-day
i !!.<]/!)
10 kg
300
15000
12
50
--
233
a
50
160
63
1800
111 00
220
300
50
8930
10700
7'|0
1000
1000
1000
I oncjcr
(u
10 kg
20
NA
12
50
--
NA
5
50
71
--
9000
2<)0
220
--
NA
8930
10700
71(0
1000
1000
1000
-term a/
70kg
70
NA
«42
50
--
NA
18
180
250
--
30000
800
750
--
NA
31250
37500
2600
3500
3500
3500
Li fct ime
70 kg
--
NA
1)2
50
1800
NA
18
180
--
--
3150
170
750
350
NA
3125
3750
NA
--
350
350
Reference Conconira t ion Tor
Potential Carcinogens b/
JlKI/l)
/() kg
0.01
0. 15
NA
0.0022
NA
0.35
NA
NA
0.3
0.0218
NA
NA
NA
NA
0.025
NA
NA
0.95
0.2l|
NA
NA
-------
CHEMICAL
Di ch loromethane*
1 ,2-Dichloropropane
p-Oioxane
Dioxin*
Endr in
Ep i ch 1 orohyd r i n*
Ethy Ibenzene*
Ethylene Dibromide*
Ethylene Glycol*
lleptach lor*
Heptachlor Epoxide*
lie xachlo robe nzene*
n-Hexane
Lead*
Lindane*
Mercury*
Methoxychlor
Methyl Ethyl Ketone"
Nickel*
Nitrate c/
EPA
One-day
10 kg
13300
--
5660
0.001
20
UlO
21000
8
19000
10
--
50
13000
--
1200
--
6'lOO
75000
--
10000 ('1 kg)
DRINKING WAN
l"
-------
1 XIIIUIT C-11
(Com i nued )
EPA
DRINKING WAII It
MEAL III ADV 1 SOR 1
ES AND
RECOMMENDED CONCENfRAllON
Hi: a 1 ih Adv i sor i es
CHEMICAL
Oxamyl
PCBs*
Pentach 1 o ropheno 1 *
Styrerie*
Tetrachloroethylene*
Toluene*
Toxaphene*
2,i4,5-TP»
1,1, 1-Tr ichlo roe thane*
Trichloroethylene"
Vinyl Chloride*
Xy lenes*
One-day
{ua/ll
10 kg
350
--
1000
27000
--
18000
500
200
1»lOOOO
--
2600
12000
1 on-day
1() kq
350
--
30(1
20000
3'lOOO
6000
80
200
35000
--
2600
7000
Longer-term a/
( U(f/ 1 )
10 kg
--
--
300
20000
19'lO
--
--
--
35000
--
13
7800
70kg
--
--
1050
70000
6800
--
--
--
125000
--
'.6
27300
1 i fet ime
(uaZJ_l_
70 kg
810
--
1050
--
--
10800
--
260
1000
--
NA
2200
Reference Concentration for
Potential Carcinogens b/
/O kg
NA
--
NA
0 . 0 1 '1
0.7
NA
0.031
NA
22000
2.8
0.015
NA
* Toxicity values necessary for risk characterization are given in Appendix C.
a/ Longer term health advisories are for exposures ranging from several months to several yea'rs and should generally be
compared only to estimated short-term concentrations (SIC).
b/ The concentration given corresponds to a potential carcinogenic risk of 1f-06. To obtain concentrations corresponding to
risks of IE-0'I and 1E-05, the 1E-06 concentrations should be multiplied by 100 and 10, respectively. To obtain concentrations
corresponding to risks of 1E-07, the 1E-06 concentrations should be divided by 10.
c/ The one- and ten-day health advisories lor nitrate and nitrite are given for both a (4 kg newborn and a 10 kg infant.
-------
OSWER Directive 9483.00-2
C-55
EXHIBIT C-12
CLEAN AIR ACT NATIONAL AMBIENT
AIR QUALITY STANDARDS (NAAQS)
CHEMICAL
CONCENTRATION
ug/m3
Carbon monoxide
40,000 (1-hour) a/
10,000 (8-hour) a/
Hydrocarbons (non-methane)
Lead
Nitrogen dioxide
Ozone
Particulate Matter
Sulfur oxides
160
1.5
100
235
260
75
365
80
(3-hour) a/
(90-day) b/
(1-year) c/
(1-hour) a/
(24-hour) a/
(1-year) d/
(24-hour) a/
(1-year) c/
a/ Maximum concentration not to be exceeded more than once per year,
b/ Three-month arithmetic mean concentration.
d/ Annual arithmetic mean concentration.
d/ Annual geometric mean concentration.
-------
OSVER Directive 9483.00-2
APPENDIX D
DETAILED PROCEDURES FOR DETERMINING TOXICITY
CONSTANTS FOR INDICATOR CHEMICAL SELECTION
The method for selecting indicator chemicals for a site, described in
Chapter 2 of this manual, requires the determination of toxicity constants
(T) . For many chemicals, these values are given in Appendix C. This appendix
(Appendix D) presents methods for calculating toxicity constants for chemicals
not listed in Appendix C.lj If, in the process of preparing a public health
evaluation for a site, such chemicals are found, you should request help from
EPA headquarters before doing these calculations. As new information becomes
available or new chemicals are identified as problems, the list in Appendix C
will be updated and expanded.
Toxicity constants, T, are medium-specific. A toxicity constant for use
w
with drinking water concentrations is referred to as T, whereas one for
concentrations in air is T, and and one for concentrations in soil is
T. Toxicity constants for potential carcinogens are based on the
ED 2J ; for noncarcinogens they are based on the minimum effective dose
(MED) and a severity of effects rating. All toxicity constants also have
standard intake assumptions built in. Units of toxicity constants are the
inverse of concentration units.
Values of T, T, and T for a variety of compounds are given in
Appendix C. In the event that values are not present in Appendix C, they can
be calculated as follows:
Potential Carcinogens
w 2 liters drinking water/day
70 kg ED1Q
0.0001 kg soil/day
[2]
70 kg ED1Q
a 20 m3 air/day
Tc = _ [3]
70 kg ED1Q
lj Appendix D is a copy of Appendix D in: EPA, Superfund Public Health
Evaluation Manual, Office of Emergency and Remedial Response, October 1986.
2j ED Q = dose in mg/kg/day at which 10% incidence above control is
observed for a tumor type showing a statistically significant incidence.
-------
OSWER Directive 9483.00-2
D-2
where the ED.n is derived from carcinogenicity dose-response data and is
expressed in mg/kg/day.
Noncarcinogens
w 2 liters drinking water/day RVe
Tn = . [4]
MED (oral)
s 0.0001 kg soil/day RVe
Tn = . [5]
MED (oral)
a 20 ra] air/day RVe
Tn = [6]
MED (inhalation)
where RVe is a rating value based on the severity of effect and scored as
indicated in Exhibit D-l, and MED is the human minimum effective dose in
mg/day for a given effect. If the MED is given in mg/kg/day, multiply it by
70 and then substitute it into the above equation.
The soil toxicity constant ( T) is incorporated as a way to estimate the
overall exposure that might be contributed by contaminated soil. Inclusion of
ST in the indicator selection process is a way to use the soil concentration
data gathered in most site characterizations, in part so that compounds found
in soil and not in air and water could be considered in indicator compound
scoring. The ST equation is based on a child's consumption of contaminated
soil as detailed in a recent ORD risk assessment of contaminated soil (EPA,
198^) .
The ORD document estimates that children between the ages of two and six
consume at least 100 mg of soil per day, and that in situations of direct
ingestion of soil (i.e., pica) the rate could go as high as 5 g per day. The
lower value was selected for this procedure because it was more comparable to
the standard consumption values used in calculating the other T values. The 5
g per day value is representative of a pathologic state (pica), and using it
to calculate T would correspond to assuming 8 liters or more as the daily
consumption of water (to reflect the diabetic who consumes 8 liters of water
per day).
Although Equations 2 and 5 are based on ingestion by a child, the intake
is not normalized to an equivalent lifetime intake. The equations use an
intake rate during childhood rather than an lifetime average daily intake to
ensure that compounds are identified on the basis of their potential to harm a
child. Thus, the equations compare a child's daily intake rate to a lifetime
average daily intake (expressed as an MED or an ED^g). wnich> strictly
speaking, may be inappropriate. Unfortunately, the most appropriate data to
use, dose-response information .for children, do not exist, and even data for
dose-response relationships in immature animals are rare. What little
-------
OSWER Directive 9483.00-2
D-3
EXHIBIT D-l
RATING CONSTANTS (RVe) FOR NONCARCINOGENS a/
Severity
Effect Rating (RVe)
Enzyme induction or other biochemical change with no pathologic 1
changes and no change in organ weights.
Enzyme induction and subcellular proliferation or other changes 2
in organelles but no other apparent effects.
Hyperplasia, hypertrophy or atrophy, but no change in organ 3'
weights.
Hyperplasia, hypertrophy or atrophy with changes in organ weights. 4
Reversible cellular changes: cloudy swelling, hydropic change, 5
or fatty changes.
Necrosis, or metaplasia with no apparent decrement of organ 6
function. Any neuropathy without apparent behavioral, sensory,
or physiologic changes.
Necrosis, atrophy, hypertrophy, or metaplasia with a detectable 7
decrement of organ functions. Any neuropathy with a measurable
change in behavioral, sensory, or physiologic activity.
Necrosis, atrophy, hypertrophy, or metaplasia with definitive 8
organ dysfunction. Any neuropathy with gross changes in behavior,
sensory, or motor performance. Any decrease in reproductive
capacity, any evidence of fetotoxicity.
Pronounced pathologic changes with severe organ dysfunction. Any 9
neuropathy with loss of behavioral or motor control or loss of
sensory ability. Reproductive dysfunction. Any teratogenic
effect with maternal toxicity.
Death or pronounced life*shortening. Any teratogenic effect with- 10
out signs of maternal toxicity.
a/ Rating scale identical to that used by EPA in the RQ adjustment
process, as described in EPA (1983).
-------
OSWER Directive 9483.00-2
D-4
information is available seems to indicate that the young are generally more
sensitive to the toxic effects of chemicals than adults. Although this
approach is not strictly accurate it errs on the more protective side, while
at the same time achieving the goal of being a simple way to incorporate soil
concentration information into the indicator selection process.
Although not used directly in the calculation of indicator scores for
potential carcinogens, a qualitative weight-of-evidence rating is considered
in the final selection of indicators. The EPA weight-of-evidence criteria
(EPA, 1986) are given in Exhibit D-2 and should be used to categorize
potential carcinogens not listed in Appendix C. The EPA approach for
determining weight of evidence is similar to the International Agency for
Research on Cancer (IARC) approach, differing primarily by having an
additional category for "no evidence of carcinogenicity in humans" and revised
criteria for defining evidence as "sufficient", "limited", or "inadequate."
REFERENCES FOR APPENDIX D
U.S. EPA, 1983. Methodology and Guidelines for Reportable Quantity
Determinations Based on Chronic Toxicity Data, External Review Draft.
Prepared by the Environmental Criteria and Assessment Office, Office of Health
and Environmental Assessment. ECAO-CIN-R245.
U.S. EPA, 1986. Guidelines for Carcinogen Risk Assessment. Federal'
Register 51:33992.
U.S. EPA, 1984. Risk Analysis of TCDD Contaminated Soil. Prepared by the
Exposure Assessment Group, Office of Health and Environmental Assessment. EPA
600/8-84-031.
-------
OSVER Directive 9483.00-2
D-5
EXHIBIT D-2
EPA WEIGHT-OF-EVIDENCE
CATEGORIES FOR POTENTIAL CARCINOGENS
EPA
Category
Description
of Group
Description of Evidence
Group A Human Carcinogen Sufficient evidence from epidemiologic studies
to support a causal association between exposure
and cancer
Group Bl
Probable Human
Carcinogen
Limited evidence of carcinogenicity in humans
from epidemiologic studies
Group B2
Probable Human
Carcinogen
Sufficient evidence of carcinogenicity in
animals, inadequate evidence of carcinogenicity
in humans
Group C Possible Human Limited evidence of carcinogenicity in animals
Carcinogen
Group D Not Classified Inadequate evidence of carcinogenicity in animals
Group E No Evidence of No evidence for carcinogenicity in at least two
Carcinogenicity adequate animal tests or in both epidemiologic
in Humans and animal studies
-------
OSVER Directive 9483.00-2
APPENDIX E
BLANK WORKSHEETS
-------
WORKSHEET 1-1
TIMETABLE FOR DEMONSTRATION OF UISK-UASEI) VARIANCE FROM SECONDARY CONTAINMENT
I. HII III Slnrlliig Dale and MiiUlilog Dnlc.
2. Place a K" at expected lime of completion fur each activity.
3. Next lo *". place expected date In parenthesis (e.g., (10/25/88))
Facility ID:
Dale:
Analyst:
Quality Control:
Starting Date
ACTIVITY
Finishing Date
WEEK
2 3 4 S 6 7 8 9 10 II 12 13 14 IS 16 17 18 19 20 21 22 2) 24 25 26
I. Source Characterization
a. Identify Physical and Chemical
Characlerislics of Consiiluenis
b. Select Indicator Chemicals
c. Determine Worst Case Release
Volumes
II. llydrogcological Characteristics
a. Characterize Climate
h. Characterize Regional and Site
Geology
c. Characterize Unsaturated and
Saturated Zones
d. Characterize Surface Water
HI. Surrounding Land Use, Water Use,
and Water Quality Characteristics
a. Characterize Ground-Water Use and
Quality
h. Characterize Surface Water Use and
Quality
c. Characterize Surrounding Land Use
and Quality
-------
WORKSHEET l-l
TIMETAHLE FOR DEMONSTRATION OF RISK-BASED VARIANCE FROM SECONDARY CONTAINMENT
(Continued)
Starting Date
Finishing Date
WEEK
ACTIVITY
/ 2 3 4 5 6 7 8 9 10 II 12 13 14 IS 16 17 18 19 20 21 22 23 24 25 26
IV. Exposure Point Concentration
a. Identify Exposure Pathways
b. Estimate Exposure Point Concentrations
V. Health Effects Evaluation
a. Compare Exposure Point
Concentrations (o Established
Health Standards
b. Estimate Chemical Intakes
c. Determine Chemical Toxicilies
d. Characterize Risk
VI. Environmental Impact Evaluation
a. Compare Exposure Point
Concentrations to Quality
Standards
b. Derive Site Specific Criteria
c. Evaluate Site Specific Exposure
Points
VII. Preparation of (he "No-Substantial
Hazard" Demonstration
a. Summarize Results of the
Risk-Hased Assessment
b. Prepare Supporting
Documentation
c. Submit to Regional Administrator
-------
WORKSHEET 2-1
PHYSICAL AND CHEMICAL CHARACTERISTICS OF CONSTITUENTS
of
INSTRUCTION:;:
1. List all chemicals and tlielr Chemical Abstract Service (CAS) lumber.
2. Refer to Exhibit C-1 and C-2 and recoi tl each chemical's solubility, vapor pressure.
Henry's law constant, Koc, 109 Kow, and half-lives In cjrnnnd water (GW), surface water (SW),
soil, and air* Refer to chemical handbooks and record each chemical's specific gravity,
viscosity and oxidation state.
Facility ID:
hate:
Analyst:
QualIty Control:
Chemical
CAS I
Water Vapor Henry's l-aw
Solubility Oxidation Specific Viscosity a/ pressure Constant log
(rag/1) State Gravity (cent Ipolse) (mm Hg) (ado-mj/mol) Koc Kow
Half-Life (Pays)
SW
Soil
Air
a/ At 20° C.
ASSUMPTION;
List all major assumptions made in the develojment of data for this worksheet:
-------
WORKSIUU 2-?
INIHCAIOR CllfMICAl 1 OX I C I I Y INIOHMAIION
Pa (jo of
IONS:
1 Record compounds from Worksheet 2-1. then refer to Ixhibit C-3 and C-'j and note
whether they are classified as potential carcinogen (PC) or noiicarc inogcn ( NC ) or both.
2. Record the rating value ( nnncarc inogcns, Ixhihit C-5) or f PA category
(potential carcinogens, Exhibit C-'t) lor each compound in each class.
If there are route-specific differences ( i . e . . oral or inhalation), record both values.
3. Refer to Exhibits C-3 and C-5 and record the toxicily constant value associated with water.
FaciIi ty ID:
Date:
Ana lyst.:
Qua I i ty Com ro I :
ChemicaI
1 oxicologic Class
(PC. NC)
Rating Value/EPA Category a/
Water loxicity Constant
( I /mg)
a/ Rating value is for severity-of-effect for noncareinogens, range is l(low) to 10(high); EPA category is a qualitative
weight-of-evidence designation for potential carcinogens; explanation of the categories is presented in Exhibit ?-2.
Information taken from Appendix C.
ASSUftmONS:
List all the major assumptions made in developing the data for this worksheet:
-------
I'a0« . of
WOllKSIIl I f 2-3
CALCUIAIION 01 OVIKAtt CIUMICAI CONCI N I UAH ONS IN TANK SYSKHS
JNSIRUCIIONS:
1. Identify tho chemicals in the lank systems (use one worksheet for each chemical). Facility II):
?. Identify tank systems that contain each chcm H::I I . Date:
3. Identify annual throughput of each lank system in liters (to convert Analyst:
from gallons to liters multiply by 3 . 78Vi) .
Quality Control:
'l. Identify chemical concentrations (minimum, maximum, representative)
in each tank system.
'j. for each tank system, calculate the annual mass of chemical handled by the tank
(the annual mass equals the product of the anniiaI throughput and concentration,
divided by 1,000,000 to convert to kilograms).
6. Calculate total annual throughput of all tanks and total annual mass of chemical
handled in all tank systems.
7. Calculate the overall chemical concentration within the tank systems (divide total
annual mass of chemical by total annual throughput and multiply by 1,000,000 to
convert to milligrams).
Chem i caI:
Chemical Concentration Annual Mass of Chemical
Annual LfJ._la.Uh_Syst^m_[m(j/i ) Hajid LSd_in_J.ank_Sys tem_Xkg I
Tank System ID Throughput (liters) Minimum Maximum Representative Minimum Maximum Representative
TotaI:
Overall chemical concentration in tank systems:
ASSU.M.PIJ.ONS: 1
List all major assumptions made in developing the data for this worksheet:
-------
woRKSiiirr 2-M
scon INC ion INDICATOR ciifMiCAt srircnoN:
OVMtAI I CONCINI NATIONS. Koc, AND log Kow VALUFS
Paqn
of
INSIHUCIIONS:
I. Write down each chemical round within tin; tank system and ils Koc and
locj Kow vnltios (from Worksheet 2-1) (uso .nliliiioii.il workshoets if necessary).
2. IT more than 20 chemicals are listed, identity those with the ten highest
Koc values with nn II and those with the ton lowest Koc values with an t.
In addition, identify those with the ten highest log Kow values with an II" and
those with the ten lowest log Kow values with .in 1". Qua
3. Record an overall minimum, maximum and "re-pi csiMita t i vo" concentration from
Worksheet 2-3 and enter it; indicate in footnotes the basis of.the representative
value (e.g., Waste Analysis Report).
i|. Record indicator chemical toxicity constant value from Woiksheet 2-2.
5. Record the freshwater chronic water quality criteria from Exhibit 1-2. II" not available state NA.
Faei I i ty II):
Date;
Annlyst:
I i ty Control:
ChemicaI
Koc log Kow . nv'-'faiL Chomt£aJ_Coi)centra t io[Llmg/_ll
Value Value Mininuin Maximum Representative a/ Reference b/
Indicator Chemical
lox ic i ty Constant
LLZJB3J
NC PC
Fresh
Chronic
Cri teria
(mg/l)
a/ Mean of reported values used as representative! concentration for all lank systems used to store or
treat the chemical; zero used for all values leported as below detection limit.
b/ Page numbers follow document designation.
ASSUMPIIONS:
list all the major assumptions made in developing the data for this worksheet; also indicate any
tnnrrimc ahnut the waste analysis data.
-------
Page of
WORKSIIffl 2-5
SCOKINC. I OH INDICATOR CIIIMICAI SflfCIION:
CAICUIAIION 01 I NO ICAI OK SCOKI VAlUfS AND HNIAIIVf. RANK I OR CARCINOGfNIC rrftCfS
INSIRUCItQNS:
1. | ist all of ttie chemicals to be considered as potential carcinogens. facility ID: '_
2. Calculate overall concentration times toxicity (Cl) values using the infoimatinn from Date:
Worksheets 2-1 and 2-2. Calculate a Cl based (in [lie overall minimum, maximum, and
representative concentrations. Analyst:
3. Rank the compounds based on their minimum, maximum, and representative indicator Quality Control:
score values. Also, enter their f PA we i cjht-of-ev i dence category in the final
coIumn.
indicator Score Value Icntative Rank Weight of
Chemical Minimum "Maximum Representative Maximum Minimum Hepresentative Evidence
ASSUMPI!QNS:
list all major assumptions made in, deve lop i ni) the data for this worksheet:
-------
Page __ of
WORKSIIF I F 2-6
SCOKINC 1011 INOICAFOR CIICHICAI SrifCFION:
CAICWAIION Of INDICAIOK SCOKI VAHI1 S AND ILNIAIIVF HANK FOR NONCARCIHOOF N 1C FflLCIS
INSIRUCI IONS:
I list nil of the chemicals to bo considered lor noiu:arc inogrsnic effects. facility ID:
2. Calculate overall concentration limes loxicriy (Cl) values using the information Da in:
from Worksheets ?-1 and 2-2. Calculate Cl values hased on the overall minimum,
maximum, and representative concentrations. Analyst:
3 Hank the compounds hased on their minimum, m;ix-irnum, and representative Quality Control:
indicator score values. Also enter the suvi; rrty-of-effects rating value(s)
i n the f inaI column.
Ra t ing
Lndjcatgr Score, ya lire leniative Rank VOJilSlS 1
Chemical Minimum * "Maximum Itepreseniative Minimum Maximum Representative Oral Inhalation
ASSUMIMIONS:
list all major assirmptions made in developing the data for this worksheet:
-------
l'n<;<.' of
WOKKSlim ?-/
SCOKINC I OK INOICA10R CIIIHICAI Sf I EC I I ON:
CAICUIAIION Of I NOICAIOK SI OKI VAl IK S AND IINIAIIVI ItANK K)K INVIRONMfNIAl II f I C I S
IONS:
1. I IM all of the chemicals 10 hi; considered loi environmental effects. facility II): _ _.
?. Ca I cti I a to indicator scores by dividing overall concentration by frosh water chronic Dale;
water quality criteria using the i nl or in.i I i on I i om Worksheets 2-1 and ?-2. Calculate
w.-itcr utia I i ty indicator score values based on the overall minimum, maximum, and Analyst:
re present a t i ve concert t ra t ions .
OuaI i ty Con11oI:
3. Hiinh the compounds based on their minimum, m
-------
Pago of
WOHKSIIlEr 2-fl
SCORING FOR INUICAIOR CIIIMICA1 SFlfCIION FOR HUMAN HtAllll FFFFCFS EVALUAIION:
fVAIUAMON Ol IXI'OSUHL /ACIOftS AND IINAI CIICMICAI SIIECFION
JNSIIUJCl IONS:
1. List the lop 15 to 20 PC and NC chemicals based on health-based indicator score (ISM) Facility ID:
values, giving their ISM values and their r,inking (use additional sheets).
Date:
?.. Refer to Worksheet 2-1 and record each chemical's solubility, vapor pressure,
Henry's law constant, Koc, and half-lives in i|ioimd water, surface water, soil, and air. Analyst:
3. Select the final 10 to 15 indicator chemicals b.ised on the guidelines presented in quality Control:
Section 2.3.3. Use your judgment -- if a compound has a high water solubility
and a long half-life, yet is ranked lower than a compound with minimal water solubility
and a short ha If-life, you may wish to move it up in the ranking.
it. Document any changes in ranking made because of exposure factors.
5. in the last column indicate with a "+" those chemicals that have been selected as indicator chemicals (1C).
a/ Water Vapor Henry's Law
I Sll Va lues .RjUihH'.U Solubility Pressure Constant M3j-fr.LiC*?-_LI)a,y5 )__
Chemical PC NC PC NC (mg/l) (mm llg) (alm-m3/mole) Koo CW SW Soil Air 1C
a/ Based on overall representative concentrations.
ASSUMPlIONS:
list all major assumptions made in the deveIupmont of data for this worksheet:
-------
Pago of
WOUKSIIH I 2-9
SCORING HM INUICAIOK CIIIHICAl SflCCIION I OH I NV I KOHMf N I A| IMPACT FVALUAIION:
EVAIDA1ION 01 I XI'OSIIIU fACIOKS AND IINAI CIIIHICAl SLILCIION
INSIRIICI IONS:
I. 1 isl the top I1) to 20 chemicals according to environmental gun Iity-basod indicator facility ID:
sco io (IS() values, giving their I SI values and their ranking. Also list chemicals
th.it could not bo scored (use additional sheet1.). Da to:
2. Refer to Worksheet 2-1 and record each chemical's solubility, vapor pressure. Analyst:
Henry's law constant, Koc, and half-lives in giouud water (CH), surface water (SW),
soil, and air. Quality Co/it ro I:
3. Select the fin.il 10 to 1'j indicator chemicals based on the guidelines presented
in Section 2.2.3. Use your judgment -- il a compound has a high water solubility
and a long ha IT-life, yet is ranked lower than a compound with minimal water
solubility and a short hair-life, you may wish to move it up in the ranking.
i|. Document any changes in ranking made because of exposure factors.
5. In the last column indicate with a "+" those chemicals that have been selected as indicator chemicals (1C).
Water Vapor Henry's law
a/ Solubility Pressure Constant Ha Lf.r_L'C£ (I>i>Y_sJ
Chemical ISE Values Ranking (mg/\) (mm llg) (a tm-m3/mo le) Koc CW SW" ' Soil Air 1C
a/ Based on overall representative concentrations.
ASSUMPI|ONS:
List all major assumptions made in the development of data for this worksheet:
-------
I'ago __ of
WOHKSIIllT 2-10
voioni riioriLts ASSOCIAUO wnn EACH IAHK SYSIEM
I NS I (<(l(: I I (IMS: facility II): _____
1. t ist each tank system, its components for which a variance is being sought Cluster:
or Tor which a variance was piev»ously qi.ml<;
-------
WORKSIU M 2-11
RfllASr MASS I'HOIIHS ASSOCI Alt I) WIIII J ACII INDICA10R CllfMICAl: MINIMUM CONCf N I RAT I ON
Page
or
INSIRUC1!QNS:
1. fill out a separate worksheet for each indicator chemical.
2. Identify tlie tank system(s) that contain tlin i ml u:a tor chemical.
3. I ist the minimum concentration within the tank systems from Worksheet 2-3.
'(. I ist the corresponding annual release volumes Iiom Worksheet 2-8 for each
tank system.
5. Calculate for tho indicator chemical the mass it; leased (in kilograms) for
each tank system (annual mass released equals the annual release volume
(in gallons) multiplied by 3./B'3'i to COMVIM t to liters, multiplied by the
-6
minimum concentration (in mg/liter), multiplied by Id to convert to
k ilog rams ).
6. Calculate the total chemical mass release;/ by summing the masses for the
individual tank systems.
facility 10:
Cluster:
Date:
Analyst:
Qua Ii ty Cont roI:
Indicator Chemical:
lank System
Minimum
Concentration (mg/liter)
Annual Volume Released
Year 1 Years 2-20 fper year)
Annual Mass Released (kg)
Year \ Years ?-2ll -(per year)
IOTAL
-------
Page of
WOHKSIIf F I 2-12
Rf.ll.ASE: MASS PHOIIUS ASSOCIA11 I) Will) EACH INDICATOR CHEMICAL: MAXIMUM CONCENTRATION
INSinilCI IONS:
1. Mil out a separate worksheet Tor each indicator chnmical. (anility ID: _ _
2. Identify the tank system(s) that contain tin: jndicntor chemical. Cluster:
3. I ist the maximum concentration within the tank systems from Worksheet 2-3. Onto:
i|. list the corresponding annual release volumes from Worksheet 2-8 for each Analyst:
tank system.
Qua Ii ty Corn ro I :
5. Calculate for tho indicator chemical the mass id eased (in kilograms) for
each lank system (annual mass released e<|uaIs tho annual release volume
(in gallons) multiplied by 3.785') to convert to liters, multiplied by the
-6
maximum concentration (in ing/liter), multiplied by 10 to convert to
k ilog rams ).
6. Calculate the total chemical mass released by summing the masses for the
individual tank systems.
Indicator Chemical:
Maximum Annual Volume Released (gallons) Annua I Mass Re leased ( kg )
Tank System Concentration (my/liter) Year I Years 2-20 (per year) Year 1 Years 2-2O (per year)
TOTAL
-------
of
WORKSIII II 2- 13
RFI EASr MASS PROMIES ASSOC I A 11 I) WIIII (ACII INIJICAIOR CHEMICAL: Rf PRI Sf N I AH VE CONCEN I RAT I ON
INS1RUCIIONS:
1. fill out a separate worksheet for each indicator chemical.
2. Identify the tank system(s) that contain tins indicator chemical.
3. list tho representative concentration within the lank systems from
Worksheet 2-3.
ll. list the corresponding annual release vo I tunes I mm Worksheet 2-8 for each
tank system.
5. Calculate for the indicator chemical, the mass released (in kilograms) for
each tank system (annual mass released equals the annual release volume
(in gallons) multiplied by 3 . 7fl5'l to convert to liters, multiplied by the
-6
representative concentration (in ing/liter), multiplied by 10 to convert to
kilog rams).
6. Calculate the total chemical mass released hy summing the masses for the
individual tank systems.
Iac iIity ID:
Cluster:
Date:
Analyst:
Qua Ii ty Cont roI:
Indicator Chemical:
lank System
Representa t i ve
Concentration (mg/liter)
Annual Volume Released (gallons)
Year 1 Years 2-20 (per year)
Annual Mass Released (kg;
Year I
Years 2-?0 (per year)
TOTAL
-------
rage
of
WOUKSIII El 'l-l
I'HOXIMIIY AND WIIIIDKAWAl KAILS Ol GKOUND-WA11 It USfRS
INSIRUC1IONS:
t. Indicate the location of ground-water wells in ihi; area.
2. list the approximate distance of the well in mete is from I lie release
source (i.e., tank system).
3. Indicate the depth of the well in meteis.
i|. Indicate tin; type of user associated with e.ich well (e.g., domestic,
residential, agricultural).
5. Specify peak, annual, and seasonal (if applicable) withdrawal rates.
6. Add any additional comments, such as the natuic of seasonal use.
Wei I
ID H
I ocat ion
Oi stance
from
He lease
Source (m)
faciIi ty ID:
Date:
Analyst:
Qua I Ity ControI:
We I I
Depth (m)
lype of User
Wi thdrawa!_Rates_ig/day}
Peak Annual Seasonal
Comments
-------
Page
of
WORKSHEET 4-2
MEASURED CHOIINII-WATEH CONCENTRATIONS OF BACKGROUND CHEMICALS
INSTRUCTIONS:
1. List all selected background chemicals and Indicator chanlcal s.
2. For each chemical listed. Identify the release source.
3. List the ranqe of measured upqradlent ambient concentration!) and median
concentration for each chemical*
4. List the range of measured downgradlent ambient concentrations and median
concentration for each chonlcal.
>. List the general or specific (If applicable) location of the sampling
point(s) used to determine the maximum measured concentration.
Facility ID:
Hate:
Analyst:
Qual Ity Control:
Chemical
Suspended
Release Source
Upqrail i eiit JUnb lent
Concent rat ions
__ | Of
Range Hodian SampI es
[)owiig^-ad lent Ambient
Concentrations
a/
Range
tedian
I of
Samples
Location of
Max Ini»i)
Measurements
Comments
cases only a single data point may be available.
-------
I'ngn of
WOrtKSIHff '1-3 I
COMPARISON OF BACKGROUND CllfMICAl CONCI NlltAl IONS IN GROUND WAIfR JO OR INKING WATffi SIANDAROS AND GUIDIIINfS
JNSirUICIJONS:
I. I isl all background and indicator chemicals. facility 10:
2. (or each chemical, list the median and maximum .imliiciu concentrations. Date:
3. List any relevant I PA standards and the somce of the standard . Analyst:
(i.e.. MCI, MCIC. WQC).a/
Qua Ii ty Control:
'I. Under the comments section, indicate whether I he background concentrations
exceed or Tall below the standards or whethei no standards are available.
Median Maximum Relevant
Chemical Concentration Concentration I PA Standard Source of the Standard Comments
a/ MCI = maximum contaminant level
MCI 0 - maximum contaminant level goal
WQC = water quality criteria
-------
Page
of
WORKSHEET l|-l|
I fU A I MINI OP I IONS (OR REDUCING CON I AH I NANF LEVELS
INSIRUCIIONS:
1. list use under considerat ion.
2. list all contaminants at levels exceeding those permissible to support the use.
3. for ench contnminant, identify the necessary contnmination reduction arid
potential methods to achieve the reduction.
Potential future Use:
Contaminant
Concentration
Current Necessary for
Maximum Potential Use
facility 10:
Date:
Analyst:
Qua Ii ty ControI:
Treatment Options
Level of Contiiiiii fjai\L_T i on tnient
Reduction Duration treatment Costs
-------
Pago of
WORKSHEET l|-5
SUIU ACE WATER CONTAMINATION SOURCES
1. list all poiential contami nat Ion sources. Facilily ID:
2. lor each source list the water body into which it discharges. Date:
3. If applicable and available, list discharye rate, contaminant Analyst.:
load allocations, and NI'Dl S permit number.
Qua I i ty Cont ro I :
Discharye Contaminant toad
Source Water Body Kate (m3/day) Allocations NPOES U Comments
-------
PJUJO of
WORKSIIfEl l|-6
HIASUHII) SUIUACI WAHH CONCfNIKAlIONS Of IIACKUIUXJNI) CllfMICAIS
INSIIUIC1 IONS:
1. list all surface water bodies in tin; area that could potentially be contaminated
by a release.
?. lor each water body list all selected backij i omul chemicals.
3. lor each chemical listed, identify the rele.isi; source.
ll. list the range and median measured ambient concentrations for each water body.
5. Identify the sampling locatlon(s) used to determine the maximum concentration.
Iac iIi ty 10:
Da to:
Analyst:
Qua Ii ty ControI:
Wai.er Body
ChcmicaI
Suspected Uelo.iso Source
Amb[ent Concentrations Number of
hange Median Samples
I ocat ion of
Max imiini
Measurement
Comment
-------
I'illJI! Of
WOIIKSIII f I >l- I
SUMMAItY 01 CUIUtl Ml AND lUlllltl USf S 01 SUKIACl WAI IKS IN I IK Aid A
INSlfUJCl IONS:
1. list nil surface water bodies that could pot cut i n I I y bo contnnii (ia Lod by a rolonsc. facility 10:
?. Provide a brief" description of the water body (e.g., lake, pond, reservoir). Date:
3. lor each water body, list the distance finm ihe lelease source. Analyst:
'I. lor each water body listed, identify current
-------
WOHKSIIfll 5-1
I'OHNIIAl HUMAN I Xl'OSUItl PAIIIWAYS
INSFRUCfJONS:
1. list all release sources, transport median i SIMS, iiiul transport media
(use additional worksheets if necessary).
?. Describe the nature of the exposuie point and its location with
respect to release source (e.g., neaiest residence to volatilization
release site, 300 feet NW). Attach a map indicating location of
system and exposure points.
J. list exposure route (e.g., inhalation, i n<|cs 11 on).
M. Report the numher of people potentially exposed at the exposure point.
>. Indicate if exposure pathways are complete (i.e., where release source,
transport mechanism, transport medium, exposuie point, and exposure
roiite all exi st).
»aciIi ty II):
Cluster/lank System:
Date:
Analyst:
Quality Control:
Re I ease
Source
T ransporl
Median i sm
I ransport
Modium
t xposure
Point
Exposure
Route
Sl7C Of
PopuI a t ion
Pathway
CompI etc?
-------
p,i-?
I'OIINIIAI INVIKOMMI NIAI HI CUM OR 1 XI'OSUIU I'AHIWAYS
[NSI RUG I IONS:
I. list nil re lease,sources, transport mcrcli.m i SIMS . antl transport media
(use additional worksheets if necessary).
?. Describe the exposure point.
3. List the exposure route ( ingestion, respiration).
'i. Describe what is affected at the exposure point (e.g., species list or
community description).
S. Attach a complete list of species, population levels, value (IT applicable)
and structures if not identified on worksheet.
FaciIty ID:
Cluster/lank System:
Oa tn:
Analyst:
Qua I i ty Conlro I :
Source
T ransport
Median! sm
Iranspoit
Mod him
Ixposure Po i nt
fxposure Route
Spec ics/Comimin i ty/
St ruetures
Pathway
CompIete?
-------
rage
ot
WORKSIU f F 5-3
CON I AM I NAN I CONCIN1RAI IONS A I HUMAN f XPOSUUf I'OINIS
INSIRUCI!QMS:
I. list nil human indicator chemicals (tiso iidil i l uiiia I
workslicnts if necessary).
?. list all release media for each chemiraI: ground water,
sn rl ace wa le r, so i I , and air.
}. I ist all exposure points for each loleasc medium.
'l. list projected short-term and long-term concent ra t ions
(lower, upper, and representative) Tor each exposure point.
()o sure to i nc I ude- backgi onnd concentrations ( i oni Worksheet
'l-?. Note that water concent ra t to/is are in m<;/ I , air con-
centrations are in mg/m3, and fish conreiitr.il ions are in imj/kg.
Attach to this worksheet all calculations documenting the
concentration estimates to this worksheet.
faci I i ty II):
Cluster/lank System:
Date:
Analyst:
Qua I i ty Cont.ru I :
ChemicaI
Re I ease
Med i tun
fxposure
Co i nl
Concent rati on Short-Ierni Concentration
Units tower Upper Repres.
tonn-Torm Concentrat jon
lowor ilppnr Repres.
-------
Pnijo of
WOHKSHCtr VI
CON I AM I NAN I COHCI H I KA I I ONS Al I NV I KONMl N I Al Id Ct I'I ()l( fXf'OSUKf I'UINIS
INSIRUCI IONS:
I. list all environmental indicator chenuca I s (usn additional
worksheets if necessary).
?. list nil release media for each chemical.
~l. list all environmental receptor exposure points for each release medium.
M. I ist projected short-term and long-teim concentiations for each
exposure point. Do sure to include tiack
-------
WORKSIIftl 6-1
COMPARISON 0[ HUMAN I XI'OSIIUI PO I N I CONCl N I RAI I ONS 1C) CS I AUL I Sill I) S1ANOAHIJS
INSIKUCIIONS: facility II):
I. Indicate exposure point and list all indicatoi (.hem ic;a I s (use additional Cluster/lank System:
worksheets if necessary).
Da t o:
?. Record each chemical's concentration range and i cprusoritai i ve value
(from Worksheet
-------
WORKSIIU I 6-2
SIIIICIIKON 1C (.HOUND-WAI IK INIAKIS
INS1KUCTIONS:
1 .
2.
3.
Indicate exposure point and estimated duration ol exposure.
correspond to whether intake is stibchronu: or chronic (e.g.,
snbchronic and /() years for chronic).
Dura tion should
3 months for
Using fxhibit 6-? and/or other available infoimation, calculate a human
intake factor by dividing ground-water intake per day by body weight (e.g.,
? I/day/70 kg = rt.029 I/kg/day).
list'all indicator chemicals (use additional woiKsheeis if necessary) and their
short-term concentrations in ground water (from Worksheet 5-3).
Cage of
FaciIi ty ID:
Cluster/tank System-:
Date:
Analyst:
'Qua Ii ty Control:
'I. Determine Snbchronic Daily Intake (SDI) us UK) ihe following formula:
SDI = Human Intake factor x Short-lent) Concentration.
F.xposure Point:
Duration of Exposure:
Populat ion:
Human Intake Factor (I/kg/day):
ChemicaI
(xposure Ho int
Short-)erm Concentration
1 m
-------
WORKSIILfl 6-3
CHRONIC GROUND-WAI I It INIAKIS
INSIRUCIIONS:
I. Indicate exposure point and estimated diiialion ol exposure. Duration should facility ID:
correspond to whether intake is siibchronic or chionii: (e.g., 3 months for
Mihchrnntc and /() years for chronic). Cluster/lank System:
2. Using Exhibit 6-2 and/or other available inl01 ma I ion, calculate a human Date:
intake factor by dividing ground-water intake per day by body weight (e.g., 2 I/day
//() kg = 0.029 I/kg/day). Analyst:
3. list all indicator chemicals (use additional worksheets if necessary) and their Quality Control:
long-term concentrations in ground water (from Worksheet 5-3).
>i. Determine Chronic Daily Intake (CDI) using the lollowing formula:
CD I = Human Intake factor x long-Term Concentration.
Exposure Point: _ Population:
Duration of Exposure: Human Intake factor (I/kg/day):
Ixposure Point
long-lerm Concentration Daily Intake
Chemical [ nig/ I )
Lower Upper Repres. Lower Upper Repres.
1 .
2.
3.
'I.
f>.
6.
7.
8.
9.
10.
-------
Page
or
HOKKSHIF r 6-'l
SlIIICIIKONIC SURrACf WAHR INfAKFS
INS IHUCI IONS:
1. Indicate exposure point and estimated duration of exposure. Duration should
correspond to whether intake is subchronic or chronic (e.g., 3 months for
subchronic and 10 years for chronic).
2. Using fxhibit 6-? and/or other available inf01 mation, calculate a human
intake factor by dividing surface water intake per day by body weight
(e.g., ? I/day/70 kg = 0.0?9 I/kg/day).
3. list all indicator chemicals (use additional worksheets if necessary) and their
short-term concentrations i n surface water (from Worksheet 5>-3).
«i. Determine Subchronic Daily Intake (SDI) using the following formula:
SDI - Human Intake factor x Short-term Concentration.
facility ID:
Cluster/lank System:
Date:
Analyst:
Qua Ii ty Control:
fxposure Point:
Duration of Exposure:
I'opu I a t ion:
Human Intake factor (I/kg/day):
ChemicaI
t xposurc Po i rit
long-term Concentration
Lower
-
Upper
Repres.
Lower
Da ily Intake
(mg/kji/diiy)
Upper
(tepres.
1.
2.
3.
it.
6.
I .
8.
9.
10.
-------
wonkSHLEI 6-5
UIKONIC SUIUACE WAUR INIAK[S
INS1KUCIIONS:
I. Indicate exposure point and cs limn ted duration <)/ <;>posure. Duration should
correspond to whether intake is subchronii: or chronic (e.g., 3 months for
siihchronic and 70 years for chronic).
2. Us i in) (xhil)it 6-2 and/or other available i nl 01111,11 i on, calculate a human
intake factor by dividing surface water intake; per day by body weight
(e.g., 2 I/day/70 kg = ().0?9 I/kg/day).
3. list all indicator chemicals (use addilion.il worksheets if necessary) and their
long-term concentrations in surface water (from Worksheet 5-3).
U. Determine Chronic Daily Intake (GDI) using the following formula:
CO I = Human Intake factor x long-Term Concent i
-------
of
WORKSIIEEI 6-6
SllltCIIHOMIC FISH INIAKIS
INSTRUCTIONS:
1 Indicate exposure point and estimated duration of exposure. Duration should
correspond to whether intake is subchronic or chronic (e.g., 3 months for
subchronic and 70 years for chronic).
2. Record the b ioconcentra t ion factor ( UCf ) for eat h chemical (from Appendix C).
3 Using Exhibit 6-2 and/or other available inform.)! ion, calculate a human
intake factor by dividing fish intake per day by body weight (e.g., 6.5 gm/day/
70 kg x IE-3 kg/gm = 9.3E-5 kg/kg/day).
i|. List all indicator chemicals (use additional woikshoeis if necessary) and their
short-term concentrations in surface water (from Worksheet 5-3).
5. Determine Subchronic Daily Intake (Sl)l) using the following formula:
SDI = Human Intake factor x BCf x Short-Term Concentration.
faciIi ty 10:
Cluster/Tank System:
Dale:
Analyst:
Qua I i ty Com ro I :
Exposure Point:
Duration of Exposure:
Populat ion:
Human Intake factor (kg/kg/day):
ChemicaI
BCf
( I/kg)
I xposure Po int
long-lerm Concentration
_.
lower
Upper
Repres.
Lower
Da ily Intake
(mq/kq/day)
Upper
Repres.
1.
2.
3.
M.
5.
6.
7.
8.
9.
10.
-------
woRKsiim 6-7
CIIKONIC I ISM INIAKf S
JNS1KUCF!QNS:
1. Indicate exposure point and cs limn led duration of exposure. Duration should
correspond to whether intake is subchromc or (.lunnic (e.g., 3 months for
subchromc and 70 years for chronic).
2. Record tho bioconcentrnlion factor (BCF) for each chemical (from Appendix C).
3. Using fxhibit 6-? and/or other available inloiiii.it/on, calculate a human
intake factor by dividing fish intake per day t>y body weight (e.g., 6.5 gm/day
/CO kg x U-3 kg/gm - 9.E-5 kg/kg/day).
i). list all indicator chemicals (use additional woiksheets if necessaiy) and their
long-term concentrations in surface water (fiom Worksheet 5-3).
5. Determine Subchronic Daily Intake (SOI) using the following formula:
SOI - Human Intake factor x DCf x Long-Term Concentration.
Fnci I i ty II):
Cluster/lank System:
Date:
Analyst:
Qua I ity Control:
Exposure Point:
Duration of Lxposure
1 .
2.
3.
'I.
Population:
Human Intake factor (kg/kg/day):
Lxposure Point
long-lerm Concentration
Chemical OCf
( I/kg)
1 owe r
fmq/M
Upper
Repres .
Da i ly Intake
(mq/kq/day )
Lower Upper
Kopr us.
6.
7.
8.
9.
JO.
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Page
of
WORKSHEET 6-8
SimCllllONIC AIK INIAKI S
INSIRUCIIONS:
1 .
2.
3.
I nil i en to exposure point and estimated duration i>l exposure.
correspond to whether intake is subchrnnic or cliionic (e.g.
Mibchronic and 70 years for chronic).
Our ,11 ion shod Id
3 months for
Using Exhibit 6-2 and/or other available i nl 01 m.i 11 on. calculate a human
intake factor by dividing air intake per day by body weight (e.g., 20 m3/day
/70 kg = 0.?9 m3/kg/day).
list all indicator chemicals (use additional worksheets if necessary) and their
short-term concentrations in air (from Worksheet l>-3).
Determine Subchronic Daily Intake (SDI) usinq tin; following formula:
SDI = Human Intake factor x Short-Ierm Concentration.
IaciIi ty ID:
CIuster/lank System:
Date:
Analyst:
Qua Ii ty Cont roI:
Exposure Point:
PopnI a t ion:
Duration of Exposure
Human Intake factor (ml/kg/day):
I xposure Po i nt
Long-lerm Concentration
Chemica 1 I m
-------
WOltKSlim 6-9
CllftONIC AIR INIAKfS
INSIIUICIJONS:
1. liulicnle oxpostiro point and estimated duration of exposure. Duration sliould
corr(!spond to whether intake is subchronic or clnonic (e.g., 3 months for
suhchronic and 70 years Tor chronic).
2. Using fxhibit (>-?. and/or other available information, calculate a human
intake factor by dividing air intake per day by body weight (e.g., 20 m3/day
/7(> kg = 0.29 m3/kg/day).
3. list all indicator chemicals (use additional worksheets if necessary) and their
long-term concent rat i ons in air (from Worksheet *>-3).
U. Determine Chronic Daily Intake (CDI) using the following formula:
CD I = Human Intake Factor x Long-Term Concentiation.
faciIi ty 10:
Cluster/lank System:
Date:
Ana Iyst:
Qua Iily ContioI:
Exposure Point:
Duration of exposure:
I'opu la t ion:
Human Intake factor (m3/kg/day):
Chem icaI
[xposure Point
Long-Ierm Concentration
Lower
Upper
__
Repres.
I ower
Da ily Intake
Upper
Hep res.
1 .
2.
3.
H.
6.
7.
8.
9.
10.
-------
Pn«jo
or
woHKSiirri 6-10
OIIIIH SUHCIIRONIC INIAKfS
INS1IUIC1IONS:
1. Indicate exposure point, typo of intake, and esl i m.i ted duration of
oxpor.uie. Duration should correspond to whether intake is subchronic
or chronic (e.g., 3 months Tor snbchronic and 70 ye.us for chronic).
2. Using (xhit)it 6-2 and/or other available i nl or m.i I i on, calculate a human
intake factor.
3. list all indicator chemicals (use additional woikshocts if necessary) and their
short-teim concentrations ( from Worksheet 'j-3).
'l. Determine Subchronic Daily Intake (SOI) usiruj tli.; lol lowing formula:
S|)l = Human Intake factor x Short-lei m Concent i .11 i on.
facility II):
Cluster/Iank System:
Date:
Analyst:
Qua I i ty Com ro I :
Exposure Point:
Duration of Exposure:
PupuI a tion:
Intake:
Human Intake factor:
Chem icaI
ixposure Point
Short- lei in (.UiiceiH ra t joit^
Lower Upper Repres.
Da i ly Intake
Lower
_
Upper
Repres.
1 .
2.
3.
4.
5.
6.
7.
8.
9.
10.
*Air concentrations, in mg/m3.
-------
WORKSIIl II 6-11
Ollll II UIHONIC INIAkf S
JNSIRUCIJONS:
1. Indicate exposure point, typo of ininko, anil i:s t im.i led duration of
exposure. Duration should correspond to whether int.-ike is subi:hronic
or chronic (e.g., 3 months Tor snbchronic: nnd'/() years for chronic).
2. Using fxhitiit 6-2 and/or other available i n( o MII.I I i on. calculate a human
i ntake I actor.
3. list all indicator chemicals (use additional worksheets if necessary) and their
long-term concentrations (from Worksheet *>-3).
l|. l)(;termine Chronic Daily Intake (CDI) using the following formula:
CO I = Human Intake factor x long-Term Concent i .111 on.
fnciIi ty ID:
CI ustcr/lank System:
Date:
Analyst:
Qua I i ty Coin, ro I :
Exposure Point:
Duration of Exposure:
Popu t a tion:
Human Intake factor:
Intake:
1 .
2.
3.
ChemicaI
Ixposure Point
Short-lerm Concentra t ion*
lower Upper Repres.
Da ily Intake
Lower
_.
Upper
____
Hepros.
5.
6.
7.
8.
9.
10.
*Air concentrations, in mg/m3.
-------
HORKSIII II 6-12
I'AIIIWAYS CON I Hint) I I NO IO F01AI fXI'DSUUT
I'age
or
IONS.-
1. list the exposure points Tor all nxposuro pathways he i ng evaluated
(from Worksheet r>-l) (use additional worksln:(!ls if necessary).
2. Determine the exposure pathways contr ibnt me) to (oial exposure for each
I i steel exposure point.
3. Note in the comments column which exposure pathways are only short-term,
which are non-quantified, and any other pertinent information.
Facility II):
(; I lister/lank System:
Date:
Analyst:
Qua Iily Control:
Fxposure Point
fxposdre I'.t tliways
Com r i but iny to
lota I (xposnrn
Comments
1 .
2.
3.
H.
-------
WOKKSIIf I I 6-13
IOIAI SOW.(IRON 1C DA I I Y INIAKf (SI) I)
IONS:
I. Indicate exposures point, mimtinr of people, and wln:tlu:r intake
estimates arc lower, rcpresenla t i ve, 01 nppci values
( romp I«to a soparnto worksho(!t for onch typo of estimate).
?. | jst all indicator chemicals (use additional worksheets if necessary).
3. Hefcr to Worksheet 6-12 and determine which exposure pathways nre
relevant for the exposure point.
i|. Record SI) I s (in mg/kq/day) for the exposure point from Worksheets 6-2,
fi-'i, 6-6, 6-fl, and 6-10 in the appropriate columns.
*). Determine total SDI by adding the component SOIs lor each chemical.
For example, ground-water, surface water, and fish intakes would
sum together for total oral SDI.
I aciIity ID:
Cluster/lank System:
Da in:
Ana Iyst:
Qua Iily ControI:
Exposure Point:
Intake estimates (circle one): lower
Upper
Itepresenta t i ve
ChemtcaI
Ground
Water
SDI
Surface
Water
SDI
r i sh
Ingest ion
SDI
Other
Ora I
SDI
Population:
lota I
Ora I
SDI
Air
SDI
Other
InhaI a t ion
SDI
lota I
Inhalax ion
SDI
1 .
2.
3.
'I.
5.
6.
7.
8.
9.
10.
-------
Page
or
WOKKSKEET 6-I'l
IUIAI CIIKONIC OAKY INIAKE (coi)
INSHUICI IONS:
1. Indicate exposure point, number of people, and whether intake
estimates are lower, representative, or upper values
(complete a separate worksheet for each typo i>< estimate).
?. list all indicator chemicals (use additional woikshoets if necessary).
3. Refer to Worksheet 6-1? and determine which exposure pathways are
relevant for the exposure point.
i|. Record CO Is (in mg/kg/day) Tor the exposure point from Worksheets 6-3,
6-5, 6-7, 6-9, and 6-1t in the appropriate columns.
5. Determine total COI by adding the component COIs for each chemical.
for example, ground-water, surface water, and fish intakes would
sum together for total oral COI.
I aci I i ty II):
Clustor/lank System:
Oa t e:
Analysl:
Qua Iity Cont roI:
Exposure Point:
Inta.ke Estimates (circle one): lower
Upper
Kuprcsentat i ve
Populat ion:
Chemica 1
Ground
Water
CDI
Surface
Wa,ter
CDI
f ish
Ingest i on
CDI
Other
Ora 1
COI
tola I
Ora 1
COI
Ai r
COI
Other
Inha la t ion
COI
lota 1
Inha lat ion
COI
1 .
2.
3.
14.
6.
7.
8.
9.
10.
-------
WOHKSIU LI 6- lr>
CHI I ICAl IOXICI IY VAIUtS
I'ago or
INSI WICIIONS:
I. list all components of the wnste or indicator chemicals (use additional
woikshools if necessary).
2. list siibchronic acceptable intake (AIS), chronic acceptable intake (AIC),
mid carcinogenic potency factor values (including <:a re i nogcn ic i ty
weight-of-evidcnce ratings marked in parentheses).
3. lor tcratogenic chemicals (indicated in Appendix C), list a separate AIS Tor that
effect only.
I nc i I i ty II):
Cluster/lank System:
Date:
Analyst:
Qua Ii ty Corn roI:
Ghent ica I
AIS
AIC
(mg/kg/day)
Ca reinogen i c
Potency ("actor
( kg-ilay/mq ) a/
ifl".? 1J tion Route :
1 .
2.
3.
I).
if!3Qs t ion Route:
1 .
2.
3.
'I.
a/ fl'A weight-of-evidence rating in parentheses lor potential carcinogens (provided in Appendix C).
-------
Page
or
WORKSHIET 6-16
CAICUIAIION Ol SUIIGIIRONIC HAZARD INDFX t OR EACH EXPOSURE POINT
INS1 RUG I IONS:
1. Identify exposure point and subchromc constituents of concern (use
additional worksheets if nocessary).
2. list the total oral subclirun ic daily intake (SI)!) and total inhalation SOI
in the appropriate columns for each chemical (in mg/kg/day).
3. I ist route-specific subchronic acceptable intake (AIS) values and calculate
route-specific SOI: AIS ratios for each chemical.
4. Sum and record route-specific SDI:AIS ratios.
5. Sum and record total (oral plus inhalation) SI)I:AIS ratios only if the SO Is
for the two routes refer to the same time peiiod. If the sum -is greater than
1, it may be possible to separate the ratios according to health endpoint and
complete a separate worksheet for each endpoint.
facility ID:
Cluster/Tank System:
Oate:
Analyst:
Qua Ii ty ControI:
Exposure Point:
Populat ion:
Intake Estimates (circle one): lower Upper Representative
1 .
2.
3.
Chemical
OraI (mg/kg/day1
SOI AIS SO I:AIS
SOI
j nhn Intion ( nu]/ki)/day )
A i S " "SI) I : AI S
5.
6.
7.
8.
Sum of Oral SI)I:AIS Ratios
Sum of Inhalation SOI:AIS Ratios -
-------
Pago
of
HOKKSlim 6-17
CAICDIAIION Ol CHRONIC IIAZAni) INOIX t OR EACH EXPOSURE POINT
JNSIKUCIIONS:
1. Identify exposure point and chronic, non-ca i <: i nogon i c const i Itionts of
concern (use additional worksheets if nocessaiy ) .
2. I ist the total inhalation chronic daily intake ((.1)1) and total oral
CD I in the appropriate columns for each for each chemical (in mg/kg/day).
3. list route-specific chronic acceptable intake (AIC) values and
calculate route-specific CL)I:AIC ratios for each chemical.
i(. Sum and record route-specific CDI:AIC ratios.
5. Sum and record total (oral plus inhalation) CI)l:AIC ratios. If the
sum is greater than 1, it may be possible to separate the ratios
according to health endpoint and complete a separate worksheet for
each endpoint.
Fac iIity ID:
Cluster/Tank System:
Oato:
Qua Ii ty ControI:
Analyst:
Exposure Point:
Intake Estimates (circle one): lower Upper Representative
Population:
ChemicaI
Oral (mg/kg/day)
SI) I AIS SOI :AIS
SOI
Inhalation (mg/kg/dny)
AIS " " SI) I : AIS
1 .
2.
3.
6.
7.
8.
Sum of Oral SDI:AIS Ratios
Sum of Inhalation SI)I:AIS Ratios -
Sum lota I of AM Rat ios
-------
Page
Of
WORKSIIEEI 6-18
CALCUIA1ION 01 POIINIIAL CARCINOGENIC RISKS FOR EACH EXPOSURE POINT
jNSHUlCILQNS:
1. Identify exposure point and potentially ca 11: i nixjen i c. const i tuents
of concern (use additional worksheets if necessary).
2. list all exposure routes for each chemical.
3. Record chronic daily intake (COIs) and carcinogenic potency factors
(including careinogonicity weight-of-evideuce, e.g.. A, Dl, B2, etc.)
for each chemical and each exposure route.
'I. Multiply the potency factor by the CDI to got ihe route-specific risk; then
sum tlie route-specific risks for each chemical.
5. ' Sum all of the chemicaI-specific risks to give an estimate of total incre-
mental, risk due to potential carcinogens.
faciIi ty ID:
Cluster/lank System:
Date:
Analyst:
Qua Iity Cont roI:
Exposure Point:
Intake Estimates (circle one): Lower
Upper
Ropresenta t i ve
PopuI at ion:
ChemicaI
Exposure
Route
cm
(imj/ky/day)
Ca re i nogen i c
Potency Factor
(kg/day mg)
Route-spec i f ic
Risk
Iota I
ChomicnI-spec!fie
Risk
Total Upper Bound Risk =
-------
P,-!
or
WORKSIUET 7-1
COMPARISON 01 INVIKONMI NIAL KECtPIOR fXPOSUlU I'D I N I CONCf N I RAT I ON
Wllll WAUR QUALITY CRIHRIA
INSIRUCI|ONS:
1. I ist all chemicals Tor the exposure point.
2. list projected total exposure point concentraI ion
from Worksheet 5-M. Indicate whether short-term or long-term concentration.
3. I ist type (e.g., criteria, lOfl) and value of relevant water
quality criteria for each chemical.
-------
woiiKsiiru A-i
If SI fOll AIM'l ICAIII I I IY Ol lilt SICONOARY CONIAINMfNI RCQUIRfMlNT IO Tllf fACILIIY
JNSIKIJC] JONS:
1. Starting witli the left-most column, dotoi mi no which gnneratur class
tho f ac iIily is in.
2. Determine which combination of accumulation turn; and amount stored
on site at one timo matches the facility conditions.
3. (Mace a check in the right-hand column of the i tiw that matches the
facility conditions. Ihe column second Iiom tho right states whether
the facility is exempt from the secondary containment roquirumcnl.
NIX I Sm-S:
If the facility is not exempt, continue with tho screening process
(Worksheet A-2).
r aci I i ly II):
Oa I e:
Analys t:
Qua Iily Cont roI:
Quantity of Hazardous Waste
Generated in a Calendar Month
< 100 kg
100-1000 kg
> 1000 kg
AccumnI ation
1 i me
Amount Stored On Site
At Any One Time
i). a .
< IflO days
> 180 days
n. a .
< IflO days
> IflO days
n. a .
11. a .
Exempt/Not Exempt Check Applicable Category
< 1000 kg
1000-6000 kg
> 1000 kg
> 6000 kg
< 6000 kg
n. a .
> 6000 kg
exempt
exempt
not exempt
not exempt
exempt
not exempt
not exempt
n. a.
not exempt
Note: If the facility is found to be exempt from the secondary containment requirement according to the table above, but
generates acute hazardous waste (as defined in
-------
or
WOIIKSIIIIT A-2
jrsi iOR ACPIiCAniiiiY 01 mi SECONDARY CONIAINMINT lUQuininrNi AND riiniuiniY
l()l< A VAUIANCI I OK INDIVUMIAI I AUKS
INSIRUClIONS:
1. lor each hazardous waste tank system or component (or which a variance
is lining sought, respond yns or no to the questions below.
?. Itegin with question 1 am) continue to thn nc;*i i ecommendod question.
HI XI SHI'S:
FaciIi ty ID:
lank System:
Date:
Ana lyst.:
Qua Ii ty Cont ro I :
If the tank system or component is deteimined lo he eligible to apply for a '
variance (i.e., a variance is not forbidden and the tank system or component is not ,
exempt from secondary containment), continue to Worksheet A-} to determine the date
by which a notice of application for a variance must be submitted for the tank
system or component.
Quest ion
((espouse
(yes/no)
Next Step ir Response Yes
Next Step If Response No
1. Does the tank system serve only as
part of a secondary containment
system used to collect or contain
releases of hazardous waste?
2. Is the hazardous waste stored in
the tank absent of free liquids, as
demonstrated by fPA Method 9095?
3. Is the tank system located inside
a building with an impermeable floor?
i|. Does tank system ancillary equipment
include abovegtound piping (exclusive
of flanges, joints, valves, and other
connections), welded flanges, welded
joints and welded connections that are
visually inspected daily, seal less or
magnetic coupling pumps that aie
visually inspected daily, or pressur-
ized aboveground piping systems with
automatic shut-off devices that ate
visually inspected daily?
Exempt.
Continue to next question.
Ixempt.
Continue to next question.
Go to question 'i.
Continue to next question.
Ancillary equipment components Continue to next question.
identified are exempt from sec-
ondary containment. Continue to
next quest ion.
-------
\ V-UIIL I IIUKll |
I [SI I OR APPLICAI1I I II Y 01 III) SICONDAIW DON I A I NMI N I RIQU I RIMINI AND ( I I C 1 1) I I I I Y
I OK A VAKIANCt I OH INDIVIDUAL 1ANKS
6.
Quest ion
!(< spouse
(yes/no)
Is the tank system or component new
(i.e., did construction begin after
July 1'i, 1986) or has the tank system
hcen repaired after July 1M, 1986 after
having leaked or been determined to be
nnf it for use?
Is the tank system or component
undo rg round?
Next Step If Hesponse Yes
Continue to next question.
Variance not allowed.
Next Step if Response No
Tank system or component is
eligible for a variance.
Tank system or component is
eligible for a variance.
-------
I'a yo
of
WOHKSIK IT A-3
(HADIIIHS I OH PROVIDING NO I I Of Of INFfNl 1O API'lY I OR A VARIANCE.
INSTRUCT IONS:
I. Ihe following deadlines have boon set lor tank owners to provide to the
Regional Administrator written notice of inirni to apply for a variance.
If tliese deadlines cannot be met, the vaii.uue application will he denied.
?. Chock only one category that describes the ha/.iidims waste tank in question.
Some categories may also require a dalo to In: written in that is determined
hy the tank age.
Cac iIi ty ID:
lank System:
Date:
Ana Iyst:
Qua Ii ty Cont roI:
NIX I SIM'S:
I. If the deadline can he mot for providing notice* of intent to apply for a variance, continue with the screening tool.
Check AppIicable
Ca tcgory
lank Descri pt ion
Dead I i no
lank used to store or treat a
waste that became hazardous after
January 12, 1987.
New tank (construction began after
July Hi. 1986)
Existing tank (regardless of whether
the ago of the tank system is known)
used to store or treat hazardous waste
identified by the following F PA hazardous
waste numbers: f()20, f021, fO^, H)26,
or F027.
Replace January 12, 1987 in the below
cutoff dates and age categories with
llie date the waste was made hazardous,
then determine which category the tank
falls under and write the deadline date
be low.
Date:
30 (Jays prior to entering a contract for
for i nstaI I a t i on.
January 12, 1987
For
j_ng _ tank^ syjLtSfll _t>C_ Jyjown _arul Documented _age:
Tank system 13 or more years old as
of January 12, 1987.
Tank system less than 13 years old as
of January 12, 1907.
January 12, 1987
Before the tank reaches 13 years in age.
Date:
5.f!h_sysieig__for_wli_ic]}__tl)e_ag« cannot be documented:
Facility less than 7 years old as
of January 12, 1987.
Facility between 7 and 13 years old
as of January 12, 1987.
January 12, 1993
(6 years after January 12, 1987)
Before the facility reaches 13 years In
age.
Date:
rhan 13 vears old
January 12, 1987
-------
WORKSIU I [ A-'l
WASIt CONSIIIUINI CONCfNIRAHONS AND COMPARISON 10 S1ANOARDS
INSIRUCMONS: facility ID:
I. List all wasto constituents (use additional woikslioets if necessary). Dnto:
2. Record each chcmic.il concent ra t ion i angn nnil representative value. Analyst:
3. (Infer to Exhibits C-8 thrnugli C-12, and/or, for fodera I ly-approved stale water Quality Control:
(ji''1 I i ly standards, the appropriate: st.iu; aijiMu-y, to obtain established water
standards. Record the value of the standard, its source (i.e.. Maximum Contaminant
level (MCL), MCL Coal (MCLC), fedora I ly-
-------
WOHKSIItf I A-5
IIYlMOCfOI OGIC CONSIOi RAI IONS
Pay is
INSUUtCI JONS:
1. Provide a response to each question.
2. If the applicant wants to provide muie accuiJli: icsponses
to the questions, the applicnnl m;iy investigate the listed
d;ita sources.
NfXI SUPS:
1. If the applicant has no know! edge or inlo iimn lolatmg to
the presented questions, in most responses indic.iiu a high
risk situation, applicant may want to lerons ider applying for
a variance.
I ;u:i I i I y II):
U.i ti::
Ana I ys| :
Qua I i I y ( mil i iu|>,m i (is
Well locjs or hydtogeo-
I ogicaI ieports.
Potent i
Lowe r
1(1 sk
II i ghcr
Yes
ft.
ft. g/
Any leakage results in immediate
contain i na t i on <>l tiiound water. Risk
a ssoc i a led with .1 "flu" answer is
di'pondeiil on ni.iuy ulhei I'.ictoi'S.
Determines iho depth ul in.itorial
Ihiough which a runt .11111 nanl must
travel to leach .in aquifer. Hie
extent of
-------
WOHKSHFl I A-t> (continued)
MYDKOCfOi OGIC CONS I Of HA I IONS
Page
lit
tines I ion
Is the net recharge rate
high or low |0-2"/yr)
a t the s i te? d/
Response
(yes/no)
O.i t a Source
u.s (;. s.
Sta I (.' Oi-p.i i I Nicitt OT
W.I I I'l IdiSOIII COS
t or.i I W.i t >'. i Sup)) I y
A()i*ii<: i os or Companies
U. S. I). A. ( So i I Conser-
va t i on St;i v i ce )
NOAA ( N.I I i nii,i I Weather
Si; r v ice )
I owe r
( ow
__
II i glier
II i
Gonorn I ly. tin; iji
tin; greatoi llic |i
vat e r contaiiit na i i
t ranspo i t to w.i i <
areas with iinrniil
li igh i ocha icji.' .11 <:
:iti'r the rcclinrt|Ci,
il nil i a I lor <)i (Mind-
in due to Creator
i .ill I c. CeniM at I y,
ni-cl ,H|II i I i:rs and
a I i| i i!,iti!f r i sk
than aieas with (onlincd aquifers.
Is the aquiTer under a
hazardous waste tank site
cofifined or iinconf i ned? e/
U.S.C.S: W.itei Rusotnces Confined
I) i v i s i on
St.) La l>i.>f>
-------
WOIIKSIIU 1 A-1) (com inuod )
IIYmtOGlOl OGIC CONSIOIKA1 IONS
Page
ul
Quest ion
Ho spouse
(yes/no)
Da la Sou i 1:1;
f'L'tentjaJ !o(| i aph 11: maps
(site cI ovaiions)
federal Insurance Adinrn-
islr ai ion:
I looil insurance rale
m.ip
I I ood ha/ard boundary
(ii.ip
No
Yi;s
I tod-prone aic.i-. i rrr I HI Id:
Coastal areas: (ro.i-.L.I I barrier
islands, erndini) slim i: I i nr.'s )
Cliannel oni: i r>ai him-ni .iicas
Wetlands ( I r r<|iiciil I y Moodod)
l(H)-ye,i r (' Inndp lain.
In the event ol .1 i < I i.'.'i'.o, flooding
will affecl ilii; l.iLr and transport
of waste constituent.
a/ Depth to water bei tig the depth to the w.ner surface or water table (i.e., pore spaces Tilled with waier) in an unconfined
aquifer, or to top of aguifer if confined.
b/ Unsaluraied zone includes soil arid rock material down to the water table or aquifer.
C/ Karst topography is characterized by closed depressions or sinkholes, caves, and underground drainage.
d/ Hecharge being the amount of water that penetrates the ground surface and reaches the water table. Depends on precipitation,
evaporation ( evapot ransp i ra I i on ), a/id unsaunaied zone media.
§/ A confined aquifer being one separated from upper materials by a layer of impermeable or low permeability ni.n tc i i ;i I .
£/ Defers to the consolidated or unconsoIida ted medium which serves as the aquifer (an aquifer defined as being a modiuin which
will yield sufficient quantities of water (or use). .
g/ A majority of beneficial use ground w.iter in tne U.S. being found at less than 50 feet.
-------
WOKKSlim A-6
SUHHOUNUINU WAIIH USi , WA I 11< QUALITY, AND I AND USE CONSIDERATIONS
INSIIUICJ JONS;
\
I. Provide a response to each question.
2. IT Hie applicant wants to provide more an mate responses
to llio questions, tlie applicant m.iy i lives t KI.I t<; the listed
data sources.
NLX.L S!f PS:
I. IT 11 ii' applicant hns no knowledge or ml 01 m.i i i on relating to
the presented questions, or most iespnnsrs indicate a high
risk situation then tlie applicant m.iy want lo leconsider applying
tor a variance.
Page
ol
I ac i I i i y ||);
ll.ili!:
Ann I y, I :
Qua I i ty Com i <> I :
Quest ion
Hesponse
(yes/no)
On I a Source
owe r
___
II i g her
Is (he ground water at or
near the hazardous waste
tank site saline (or have
a total dissolved solids
(IDS) concentration over
10.1(00 mg/l) to an extent
which would not allow
drinking or other benefi-
cial uses?
Is giotind water at a site
considered to be ecologi-
cally vital (i.e., does
ground water supply a unique
terrestrial or aquatic
habitat associated will)
surface water bodies that
if polluted would destroy
a tin i qtie hah i tat)?
Sensitive ecological
include:
systems
a) Does ground water at a
site supply a habitat
for an endangered or
threatened species of
animals and/or plants?
N.it i on Water Well Asso-
c i.) t i on I i bra ry ( Oh i o )
U. S.<;. S. :
IJ.i si M Investigations
NAWOIHa/
Aimy Corps of Engineers
t oca I sources:
I'I ami ing Hoards
Government Councils
Stati: I nv i ronmenta I
Protection Offices
Stale Un i ve rs i t i es
U.S. I i i,h and
Wildlife Service
State liidamjered Species
Coo i d i n,i tor
National Park Service
U.S. forest Service
U.S. dm c;au of Land
Management
Aiiny Corps of Engineers
Yes
No
No
Yes
No
Yes
IT yes. and is hyil i oiji-o I og i c:a I I y
isolated and is ol limited benefi-
cial use, m.iy hi* .ipp i upr i a 1C lo
continue sr;r i;i:n i ri«j and variance
p rocess.
If ground water is i-ro loq ica I ly
vital a success I u I variance;
demons 11 n l i on is tin I i ko ly.
Pursuant to the
Act or wn.
I ii(l.m<)<.''<
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WOliKSIICtl A-6 (conlinund)
SUKKOUNDINC WAI IK t/SI . WAI IK QIMLIIY. AND I AND US( CONSUMMATIONS
Page
Quest ion
Response
(yes/no)
Data Source
.
Lower
. ___
Higher
COIIIIIIIMI t s
b) Is hazardous waste tank
located in wetlands?
No
Yes
c)
Is hazardous
located in a
a rea?
waste tank
cua staI
Is hazardous waste tank
located in any other
sensitive environmental
ari.'a -- such as water-
sheds selected by state
and local governments
for protect ion''
No
No
Yes
Yes
Wetlands aie ero I<><| ira I ly sensitive
as they suppiti t vernation adapted
Tor life in :..i l in a i ril soil condi-
tions. May In: |>i oi n i ccl under slate
statutes, the ('. ir.m W.iu.-r Act, or
txeeutive Order liyjd.
Hay hi! reqiilatod iiiulei the Constnl
Zone M.in.T<)(Miioiii. AIM. or State Coastal
Zone Management I'r o<| i ams .
Is ground water at or nea r
a hazardous waste tank site
"i rreplaceable"?
Tins can be assessed by the
following questons:
a) Does ground water serve _
a substantial population?
b) Is ground water of sur-
founding hazardous waste
tank site located in
areas where there is no
alternative source of
drinking water or an
insufficient alternative
source for a substantial
populat ion?
I oca I W.i te r Supp ly
ACJCMC i <;b arid Companies
No
Yes
No
No
Yes
Yes
If () i omul water is i n t;p I .iceab Ic and
highly vu literal* !< in roiii ;inn nn t ion,
a successful va r i ance diMiionstra t ion
i s tin I i ke I y .
A substantial popu I a t ion be i nij
approx i in.i to I y ;">ui> ponpli; wiliiin or
near the ?-milo ii-vii.-w ladius. b/
Includi.-s islands, pen i nsu I as , and
isolated giound w;il»!r over bedrock.
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HOUKSIIltl A-6 (continued)
SURROUND INC WAIIIt USI . WAII ft QUAIIIY, ANO I AND USC CONS) III RAI IONS
Page
of
Quest ion
Response
(ycis/no)
i l.i Som co
Potent i a J
I owe r
Risk
II i (jiier
Comment
Is ground water at or near
hazardous waste tank situ
located in an aquifer desig-
nated as a Sole Source Aquifer
under tlie Safe Drinking Water
Acf
I ora I H.I lor Supp I y
A(|(.MIC i cs .iiid Companies
No
Yes
If yes, potential i i sk is greater.
Is ground water at or near
the site a current or
potential source of
drinking water?
Can be assessed by:
a) Aie there operating
drinking water wells
(or springs) in the area
(within the 2-tni le
rov i (!w rad i us )?
b) Would a well or spring
in Liu: j i ca be capable
of yielding a quantity
of drinking water suf-
ficient for the needs
of an average family
( 1'jO ga l/dayp
I oca I W.i ler Supp ly
Agencies and Companies
No
Yes
If yes, potential iisk is greater.
Is the hazardous waste tank
located near a scenic river
or recreational area such
that leakage of hazardous
waste would adversely affect
the area?
National I'ark Service
County Recreation
Depa r tment
NO
Yes
Such areas may he piutccind undor
State statutory and/or regulatory
author ity.
Are then; agricultural
lands located in the area
of the hazardous waste
tank?
U.S. Dep.i i tine Ml of
Ag r icuIiure (So i I
Consoivation Service)
If so, can potentially
adverse effects be iden-
tified if leakage occurs
from a hazardous waste
tank?
No
Yes
Protection policies a 11: identified
in the USDA l.uiiiland Pi nl <:c l i on
Policy and the ll'A's "Poliry to
Protect I nv i roniniMii a I I y Significant
Agr icu I tin a I I .mils . "
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WOHKSHH I A-6 (continued)
SUiUtOUNOINC, WM I It IISl . WAUR QUAIMY. AHO LAND USf CONS I OfRAl IONS
Page;
Quest ion
Hcsponse
(yes/no)
Da I <-' Source*
( a]
lower
l(i sk
Higher
Is ha/ardoiis waste tank
located such that releases
could migrate directly to
drinking water or a drink-
ing water supply?
I oca I W.i lei Supp I y
Agencies and Companies
No
Yes
If yes, can po:,e .1 ihrt*ai to tiiunnn
heaIih.
Does (jround water at or near
a ha/aidous waste site dis-
charge to surface water
hod ins that serve as a
drinking water supply
U. S.(,. b.
II,ism Investigations
NAWDlx a/
local V/.uei Supply Agencies
.mil Conipa/i i es
No
Yes
If yes, snrlace-watei gnaIity may he
degradeil.
a/ National Hater Data Exchange
b/ Source: IPA, OtiideJ,; nes f or Croiiijd^Wa tor (. I ass i f i ca t ion Urider the CPA Crotind-Water Protection Stiateijy. <>l I " i; <>t
Ground-Water Protection, Oecemher 19fio.
-------
WOKKSIIfll A-7
or POKNIIAL EXI-OSUIU PAIIIWAYS
JNSJIUKM |pNS:
1. I 1st all release soiucos and mechanisms l>y release medium.
?. Describe the nature of the exposuie point and its local ion
with respect to release source (e.g., neairsi potable well
to release site, 300 feet NW). Oenoli: s i (jn i f i c.in t exposure
points with an asterisk.
3. list exposure route (e.g., ingeslron).
'(. Report thn number of people potentially exposed at the exposure point.
>. Determine number, location, and nature of sensitive population.
6. Mark whore exposure pathways are complete (i.e., where release source,
transport medium, exposure point, and exposure route all exist).
Page
f ac: i I i ty II):
Date:
Analyst:
Qua I i ty Com ro I :
of
He I ease/
Transport Medium a/
Release Source/
Mechani sm
Ixposure
Co r nt
exposure
Route
Number of
Peop le
Sens i t ive
Copulat ion
Ca thway
Complete
Ground water
Surface water
a/ Direct air exposure need not be considered because secondary containment generally would not significantly reduce
risk due to direct air exposure. lor abovoground tank systems containing highly volatile constituents, however,
secondary containment, by restricting the surface area over which a release could spread, would reduce the
volatilization rate of the constituent and, hence, the risk from direct air exposure.
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