EPA/530-SW-87 031
OSWER DIRECTIVE
9481.00-11
INTERIM FINAL
ALTERNATE CONCENTRATION LIMIT
GUIDANCE
BASED ON §264.94 (b) CRITERIA
PART II
CASE STUDIES
OFFICE OF SOLID WASTE
WASTE MANAGEMENT DIVISION
U.S. ENVIRONMENTAL PROTECTION AGENCY
401 M STREET, S.W.
WASHINGTON, D.C. 20460
MAY 1988
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OSWER Directive 9431.00-11
DISCLAIMER
These case studies constitute Part II of the ACL Guidance Document. They are
intended to assist Regional and State personnel in exercising the discretion
conferred by regulation in evaluating applications for alternate concentration limits
(ACLs) submitted pursuant to 40CFR 264.94. Conformance with the ACL guidance is
expected to result in ACL applications that meet the regulatory standard of
protecting human health and the environment. However, EPA will not in all cases
limit its review to demonstrations that comport with the guidance set forth herein.
This document is not a regulation (i.e., it does not establish a standard of conduct
that has the force of law) and should not be used as such. Regional and State
personnel must exercise their discretion in using this guidance document as well as
other relevant information in determining whether an ACL demonstration meets
the regulatory standard. -
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ACKNOWLEDGEMENTS
These case studies were developed by the EPA's Office of Solid Waste under
the direction of Dr. Vernon Myers, Chief of the Ground-Water Section of the Waste
Management Division. Trie case studies were prepared by the joint efforts of Dr.
Myers, Mr. Mark Salee of the Permits and State Programs Division, and Mr. Jerry
Garman of the Waste Management Division. Technical and production assistance
was provided by NUS Corporation.
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OSWER Di recti ve 9481 00-11
PREFACE
The hazardous waste regulations under the Resource Conservation and
Recovery Act (RCRA) require owners and operators of hazardous waste facilities to
utilize design features and control measures that prevent the leaking of hazardous
waste into ground water. Further, all regulated units (i.e., all surface
impoundments, waste piles, land treatment units, and landfills that received
hazardous waste after July 26, 1982) are also subject to the ground-water
monitoring and corrective action standards of 40 CFR Part 264, Subpart F. To
establish the facility's ground-water protection standard (GWPS) under Subpart F
(40 CFR 264.92), the Regional Administrator is required to establish in the facility
permit, for each hazardous constituent entering the ground water from a regulated
unit, a concentration limit that cannot be exceeded. The concentration limits are
the "triggers" that determine when corrective action is required.
There are three possible concentration limits that can be used to establish the
GWPS:
I. Background levels of the hazardous constituents,
2. Maximum concentrations listed in Table I of Section 264.94(a) of the
regulations, or
3. Alternate concentration limits (ACLs).
The first two levels are established in the facility permit as the GWPS, unless
the facility owner or operator applies for an ACL However, some States have non-
degradation policies (which are either regulatory or statutory requirements) that
prohibit the release of any pollutants into the ground water. These policies may
prevent the use of an ACL altogether if the State has an authorized program for 40
CFR Part 264, Subpart F.
An Announcement of Availability of Part I of the ACL Guidance Document was
noticed in the Federal Register on July 22, 1987 (52 FR 27579). That document
provides guidance to RCRA facility permit applicants and writers concerning the
establishment of ACLs. To obtain an ACL, a permit applicant must demonstrate that
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OSWER Directive 9481.00-11
the hazardous constituents detected in the ground water will not pose a substantial
present or potential hazard to human health or the environment at the ACL levels.
ACLs are granted through the permit process under Parts 264 and 270, and are
established in the context of the facility GWPS. The 19 factors, or criteria, that are
used to evaluate ACL requests are listed in Section 264.94(b) of the regulation.
Detailed information on each of these criteria is not required in every ACL
demonstration because each demonstration requires different types and amounts
of information, depending on the site-specific characteristics. A separate chapter of
the ACL Guidance Document, Part I, is devoted to each of these criteria. The criteria
are briefly discussed, along with the type, quantity, and quality of information that
should be provided, depending on the site-specific characteristics.
The following is a synopsis of the policy described in Part I of the ACL Guidance
Document. The reader is referred to Part I for a more comprehensive explanation of
the ACL policy.
ACL Definitions
To establish ACLs, two points must be defined on a RCRA facility's property
(see Figure 1): the Point of Compliance (POC) and the Point of Exposure (POE). The
POC is defined in the Subpart F Regulations (40 CFR § 264.95) as a "vertical surface"
located at the hydraulically downgradient limit of the waste management area that
extends down into the uppermost aquifer underlying the regulated unit The POC is
the place in the uppermost aquifer where ground-water monitoring takes place and
the ground-water protection standard is set. The ACL, if it is established in the
permit, would be set at this point.
The point of exposure (POE) is the point at which it is assumed a potential
receptor can come in contact, either now or in the future, with the contaminated
ground water. Therefore, the ground-water quality at the POE must be protective
of that receptor. For example, a facility may have a ground-water contaminant
plume restricted to a small portion of its property. In this case, it may be
appropriate to assume that people will be exposed through a drinking water well to
the ground water immediately at the edge of the plume. The ground water at that
point, the POE, must then be safe for human consumption. Likewise, if the ground-
water contamination is discharging to onsite surface water, the potential receptor
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r
Regulated
Unrt
_________
Point of
Compliance
Point of
i /- Paeil
i £_.
FKility Boundary
Exposure
PLAN VIEW
Regulated
Point of
Compliane
Point of
Exposure
CROSS-SECTION VIEW
POINT OF EXPOSURE (POE) - Point at which potential
exposure to contaminants is assumed. Location is site
specific. Allowable exposure is met here.
POINT OF COMPLIANCE (POO - The point on the downgradiant
side of the unit where the ground-water protection
standard is met. The ACL is set here.
CONTAMINANT PLUME - The volume of ground water that
contains the leaking pollutants.
FACILITY BOUNDARY - The property boundary of the
facility.
REGULATED UNIT - The area where the hazardous
wastes are kept (landfill, surface impoundment).
Figure 1. Definitions
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may, in some cases, be an aquatic organism. In this example, the aquatic organisms
must be protected from adverse effects of the discharging contaminants.
Understanding and identifying the spatial relationship between the POC and
the POE is critical in the establishment of an ACL Mechanisms that attenuate
contaminants may be considered .only over the area between the POC and the
downgradient POE. If the POE is established at the POC, then no form of
attenuation will be considered in setting the ACL In such a case (POC = POE), the
ACL would be equal to the allowable health or environmental exposure level, with
the assumption that exposure would occur at the waste management unit
boundary. However, if the POE is removed a specified distance from the POC, then
appropriate and conservative estimates of contaminant attenuation may be used in
calculating the ACL. These mechanisms of attenuation would only be considered
over that distance between the POC and the POE.
ACL Policy
Experience gained over the last several years has allowed the Agency to
develop a better understanding of ground-water contamination problems. This has
led EPA to develop general policy guidelines for the use of ACLs at RCRA hazardous
waste disposal facilities. These guidelines are designed to establish an ACL
procedure that will be protective of human health and the environment.
Three basic policy guidelines have been identified to assist the permit writer
and applicant in implementing the ACL process for useable ground water:
1. Ground-water contaminant plumes should not increase in size or
concentration above allowable health or environmental exposure levels;
2. Increased facility property holdings should not be used to allow a greater
ACL; and
3. ACLs should not be established so as to contaminate offsite ground
water above allowable health or environmental exposure levels.
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Useable ground water is either a current or potential drinking water resource
or ground water that has some other beneficial use. ACLs in unusable ground water
will be assessed on a case-by-case basis.
Examples
To provide national consistency in calculations used to estimate the potential
impacts of releases of hazardous constituents to ground water from regulated
units, Agency policy is that the points of exposure be assumed as discussed below.
These POEs were chosen because the Agency believes that they are realistic and
conservative estimates of where environmental or human receptors would likely be
exposed to the contaminants.
Case 1: For regulated units located above useable ground water where
ground-water contamination has not been detected at the time of permit issuance,
the potential POE will be assumed to be directly at the POC (Figure 2). That is, for
units at which no ground-water contaminant plume exists, the potential point of
exposure is assumed to be at the waste management unit boundary. Therefore, no
attenuation can be presumed for contaminants that leach from a unit in the future.
Fate and transport arguments cannot be used to support ACL demonstrations if no
ground-water contamination plume exists at the time of permit issuance. This
policy will help to prevent contaminants from entering the ground water above
allowable health and environmental levels. All new units seeking permits for
operation and old units that have not detected contamination will be held to this
policy.
Case Study 1 is an example of an ACL application where contamination of
ground water at a facility has been detected at the POC after permit issuance. In
this example, the ground water under the facility is useable as a drinking water
source. Therefore, the potential POE is assumed to be at the POC. ACLs were
derived directly from the maximum allowable concentrations.
Case 2: For units located above useable ground water that have existing
contamination that is confined to the facility property, the POE will be assumed to
be no farther from the POC than the outer edge of the existing plume (Figure 3). if
the permitting authority concludes it is protective of human health and the
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| Regulated j
I Unit i
i i
j .— Facility Boundary
Point of
Compliance
and
Point of
Exposure
PLAN VIEW
Ragulatad
h Unit—H
Facility
Boundary
Watar Tabte
Point of
Compliance
and
Point of
Exposure
CROSS-SECTION VIEW
Figure 2. Casel: No Contamination at Original Permit Issuance
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OSWER Directive 9481.00-11
r
Point of
Compliance
Point of
! Exposure
Facility Boundary
i /- raeimy Boundary '
PLAN VIEW
^ Ragulatad ,
p—Unit —H
Facility
Boundary'
Point of
Complianca
Point of
Exposure
CROSS-SECTION VIEW
FigureB. Case 2: Contamination Confined to Facility Property
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OSWER Directive 9481.00-11
environment, then the point of exposure may be set at the leading edge of the
plume. In this situation, mechanisms of contaminant attenuation (fate and
transport) may be considered in establishing the ACL at the point of compliance.
Monitoring for the ACL constituents at the POE should be performed to verify the
attenuation mechanisms that were accounted for.
Case Study 2 is an example of an ACL application where ground-water
contamination is confined within the facility boundary. In this example the ground
water under the facility is useable as a drinking water source. The POE was set at
the edge of the contamination. Attenuation between the POE and POC, and the
maximum allowable concentration levels at the POE, were used to derive the ACLs.
Case 3: For units located over useable ground water, if the leading edge of
the plume extends off the facility property, the POE will be assumed to bt no
farther from the POC than the facility property boundary (Figure 4). Fate and
transport arguments may then be applied to the ground-water contamination
between the POC and the POE at the facility boundary, assuming there is no
possible route of exposure on the facility property. At no time may the designated
POE be beyond the original facility boundary.
Case Study 3a is an example of an ACL application where ground-water
contamination has migrated off the facility property. In this example ground water
under the facility is useable as a drinking water source. The potential POE was set at
the facility boundary. Because the boundary of the facility was near the POC, no
attenuation between the POC and POE was assumed. The ACLs were derived from
maximum exposure concentrations at the POE.
Case Study 3b is also an example of an ACL application where ground-water
contamination has migrated off the facility property. The ground water under the
facility is potentially useable as a drinking water source; however, use is not
expected in the near term. Because the facility is closing, no attenuation of the
contaminants was assumed and the potential POE was set at the POC. The ACLs
were derived from maximum exposure concentrations at the POE.
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j Regulated
j Unit
i
Facility Boundary
Point of
Exposure
PLAN VIEW
Regulated
•Unit
Facility
Boundary ""^\
Point of
Compliance
Point of
Exposure
CROSS-SECTION VIEW
Figure 4. Case 3: Contamination that Extends Offsite
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Case 4: ACLs may be based on contaminant discharge into a surface water
body if a facility owns the property up to the surface water body (Figure 5). The
permitting authority should allow this only if: (1) the contaminant plume has
already reached the surface water body, (2) the contaminants do not cause a
statistically significant increase over background in the surface water
concentrations of those contaminants, and (3) the contaminants will not reach a
receptor at an unsafe level before they reach the surface water body. Though it
may be acceptable to allow some contaminants in the ground water to discharge
into a nearby surface water body, in no case may the ACL be derived so as to allow
releases into that surface water body that result in a statistically significant increase
in the concentration of the contaminants in the surface water body.
Case Study 4 is an example of an ACL application where ground-water
contamination discharges to a river. In this example, ground water under the
facility is useable and the river sustains a sport fishery. None of the contaminants
have been detected at statistically significant levels. The ACLs were derived from
allowable surface water exposure levels and current levels found in the ground
water.
Case 5: For those units over a non-potable aquifer, the location of the POE will
be established on a case-by-case basis (Figure 6). Such non-potable aquifers will
usually be highly saline, containing more than 10,000 ppm total dissolved solids. In
such situations, protection of environmental receptors may be the overriding factor.
In any case, the ACL must be established so as to pose no unacceptable risk to public
health and the environment. To apply this option, the permit applicant must
thoroughly demonstrate that the nonpotable aquifer is isolated from any potable
aquifer.
Case Study 5 is an example of an ACL application where ground-water
contamination has migrated off the facility property. In this example ground water
under the facility is highly saline. The proposed ACLs rely on fate and transport
considerations, and were based on the current levels at the POC.
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OSWER Directive 9^31 00-1
Point Of
Compliance
• Facility Boundary
No Statistical
Significance
I
PLAN VIEW
Facility
Boundary
Regulated
U—Unit—*j
Point of
Compliance
No Statistical
Significance
CROSS-SECTION VIEW
Figure 5. Case 4: Contamination Discharging into a Surface Water Body
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OSWER Directive 9481 00-
Point of
Exposure
• i- Facility Boundary
PLAN VIEW
Ragulatad
[« Unit—-»j
Faeilrty
Boundary "Nv
Point of
Compliance
Point of
Expoturt
CROSS-SECTION VIEW
Figure 6. Case 5: Contamination Offsite and in a Naturally Non-Potable Aquifer
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CASE STUDIES
These case studies are a series of examples of the type of information that
would be appropriate for ACL demonstrations under 40 CFR Part 264.94(b). They
are designed to serve as models to aid in implementing Part I of the ACL Guidance
Document. As such, they represent the five types of ACL cases presented in Part I.
These case studies are hypothetical examples based in part on actual hazardous
waste facilities. In many cases, data from these actual facilities have been
manipulated to better fit the type of ACL demonstration being presented. The data
on specific hazardous constituents related to toxicity and environmental fate may
not be current. ACL applicants and reviewers should always check with the U.S. EPA
for the current status of toxicity and fate information of hazardous constituents.
Also, throughout the case studies the term "potency factor* is used to identify
toxicity data for carcinogenic compounds. As used in the case studies, this term is
equivalent to a qi* or a slope factor. It is not the same as the "F factor", whichf is
also termed the potency factor in the Cancer Reportable Quantity Methodology. ;
The case studies focus on presenting and organizing the arguments that would go
into ACL demonstrations; they are not meant to be comprehensive and exacting
models of ACL demonstrations. Actual ACL demonstrations may require more
specific supporting data and analyses.
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Case 2
Case 3a
Case 3b
Case 4
OSWER Directive 9481.00-11
SUMMARY OF CASE STUDIES
Case 1
• No ground-water contamination at initial permit issuance
• Northeastern U.S.
• Useable ground water-
• ACLs based on POE equal to POC
• Ground-water contamination confined to facility property
• Southeastern U.S.
• Useable ground water
• ACLs based on POE at edge of plume
• Ground-water contamination off facility property
• Northeastern U.S.
• Useable ground water
• ACLs based on POC at facility boundary
• Ground-water contamination off facility property
• Western U.S.
• Useable ground water
• ACLs based on POE at facility boundary
• Ground-water contamination discharges to surface water
• Southeastern U.S.
• Useable ground water
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• ACls based on no statistically significant increase over background in the
surface water
CaseS
• Ground-water contamination off facility property
• Western U.S.
• Saline aquifer
• ACLs based on fate and transport considerations
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ACL
CASE STUDY 1
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CONTENTS
SECTION PAGE
1.0 EXECUTIVE SUMMARY 1-1
2.0 INTRODUCTION 2-1
2.1 FACILITY DESCRIPTION 2-1
2.2 APPROACH TO ACL DETERMINATION 2-1
2.3 REPORT ORGANIZATION 2-3
3.0 IDENTIFICATION OF ACL CONSTITUENTS 3-1
3.1 HAZARDOUS CONSTITUENTS IN THE WASTE 3-1
3.2 EXTENT AND DEGREE OF CONTAMINATION 3-1
4.0 GENERAL INFORMATION 4-1
4.1 LAND USE 4-1
4.2 WATER USE AND USERS 4-1
4.3 PRECIPITATION 4-3
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION 5-1
5.1 REGIONAL GEOLOGY 5-1
5.2 SITE GEOLOGY 5-1
5.3 GROUND-WATER HYDROLOGY 5-6
6.0 EXPOSURE PATHWAYS 6-1
6.1 POTENTIAL HUMAN EXPOSURE 6-1
6.2 POTENTIAL ENVIRONMENTAL EXPOSURE 6-1
6.3 MAXIMUM ALLOWABLE EXPOSURE CONCENTRATIONS 6-2
7.0 DEVELOPMENT OF ACLs 7-1
8.0 GROUND-WATER MONITORING PROGRAM 8-1
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CONTENTS (continued)
REFERENCES
R-1
APPENDICES
B
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
CHEMICAL AND PHYSICAL PROPERTIES AND
IRIS (INTEGRATED RISK INFORMATION SYSTEM)
DATA BASE FOR 1,1,-DICHLOROETHYLENE,
TOLUENE, 1,1,1-TRICHLOROETHANE,
TRICHLOROETHYLENE, AND XYLENE
A-1
B-1
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05WER Directive 9431 00-n
TABLES
NUMBER PAGE
3-1 Appendix IX Hazardous Constituents Present in the Landfill 3-2
3-2 Maximum Concentrations of Hazardous Constituents 3-4
Observed in the Ground Water Near the Landfill
4-1 Inventory of Wells Within One Mile of the Facility 4-3
5-1 Measured Permeability and Hydraulic Gradient 5-7
6-1 Maximum Allowable Exposure Concentrations 6-3
7-1 Proposed Alternate Concentration Limits 7-2
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OS WE R Directive 9481.00-11
FIGURES
NUMBER PAGE
2-1 Site Layout and Topography 2-2
3-1 Location of Monitoring Well Clusters 3-3
4-1 Land Uses 4-2
5-1 Regional Topography 5-2
5-2 Location of Geologic Cross Sections 5-3
5-3 Generalized Site Stratigraphy 5-4
5-4 Upper Till Water Table Contours 5-5
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1.0 EXECUTIVE SUMMARY
This case study is a hypothetical example of an application for alternate
concentration limits (ACLs) where contamination in ground water at the Facility 0
point of compliance (POC) has been detected after permit issuance. This case study
is an illustration of Case 1 as described in Parti of the ACL Guidance Document. Part
I states that for regulated units located above useable ground water that have not
detected ground-water contamination at the time of permit issuance, the potential
point of exposure (POE) will be assumed to be at the POC.
Facility D received a RCRA operating permit for its secure landfill two years
ago. At the time of permit issuance, contamination had not been detected in the
ground water; thus, the permit contained a detection monitoring program. This
ACL application is part of Facility D's application for a permit modification as
required under 40 CFR 264.98(h)(4) and (5). *
Facility D is on a glacial plain near one of the Great Lakes. The .area
surrounding the facility consists largely of industrial facilities, commercial property
and some open grassy areas. The nearest town is 1.6 miles to the northwest.
Another community lies 2 miles to the northeast. There are no private residences
within a one-mile radius of the landfill on the Facility D property.
Three of the fourteen wells at the compliance point exhibit elevated levels of
ground-water contaminants. None of the downgradient wells were contaminated,
which suggests that the contamination has not migrated a significant distance past
the POC. This application specifies ACLs for 1,1-dichloroethane, toluene, 1,1,1-
trichloroethane, trichloroethylene, and xylene.
All drinking water in the region is provided by a public water distribution
system that is supplied by surface water sources. The major regional source of
ground water is the glaciolacustrine silt/sand (GSS) aquifer. Although the GSS is of
relatively poor quality (mean TDS of 200 mg/l), its use is not restricted. However,
there are no private wells within the three-mile radius.
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The potential pathway for human exposure is assumed to be oral ingestion of
contaminated drinking water from wells developed in the GSS aquifer at the POC.
Maximum allowable concentrations for drinking water were calculated for each of
the five contaminants. These drinking water concentration limits were used as the
basis for the proposed ACLs. These ACLs do not take into account contaminant
attenuation because the POE is the Same as the POC.
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2.0 INTRODUCTION
This document is a hypothetical example of an application by Facility D for
Alternate Concentration Limits (ACLs) under 40 CFR 264.94(b) and 264.98(h)(5) for
specific hazardous constituents detected in the ground water at the facility. The
five constituents are: 1,1-dichloroethylene, toluene, 1,1,1-trichloroethane,
trichloroethylene, and xylene.
2.1 Facility Description
Facility D disposes of a variety of industrial wastes that contain some
hazardous chemicals. This ACL application addresses ground-water contamination
beneath the active landfill at the facility. The active landfill has six secure cells; two
of them (cell 5 and cell 6) are currently in operation, and four (cells 1, 2, 3, 4) have
been closed. The landfill is in the southern portion of the facility property, as shown
in Figure 2-1. Cell 5 occupies the northeastern corner of the landfill area and cell 6
occupies the southeastern corner of the landfill area.
The closed landfill cells were constructed with synthetic liners placed above
compacted clay liners. These four units were closed in accordance with applicable
regulations in 1983. The two operating units have been constructed to meet
minimum technology standards. Both active cells have a double synthetic liner
system above a compacted clay liner with leachate collection systems above and
between the liners.
2.2 Approach to ACL Determination
Approximately two years ago, Facility 0 was issued a permit under 40 CFR
124.15. At the time of permitting, contamination had not been detected in the
ground water. As a result, the permit contained a detection monitoring program
for ground-water monitoring. Recently, contaminants were found in the ground
water above background concentrations. These contaminants have not been found
above background concentrations outside of the facility boundary. This ACL
application is being submitted as part of a permit modification to establish a
compliance monitoring program in the facility permit.
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FACILITY D BOUNDARY
LEGEND
^&~~ Elevation (feet. MSL)
0 500 1000 1500
Scale. FMt
1
m
30
O
3
FIGURE 2-1. SITE LAYOUT AND TOPOGRAPHY
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Part I of the ACL Guidance Document (EPA, 1987a) establishes five cases for
ACL demonstrations. This application by Facility D meets the conditions of Case 1
because the facility is located over useable ground water and contamination has
only recently been detected at the point of compliance (POC). Because it is EPA
policy that contaminant plumes not increase in size or concentration, the assumed
point of exposure (POE) will be the same as the POC. Thus the proposed ACLs are
equal to the maximum allowable exposure concentrations for drinking water.
2.3 Report Organization
This application is presented in eight sections: executive summary,
introduction, identification of ACL constituents, general information, geologic and
hydrologic information, exposure pathways, development of ACLs, and ground-
water monitoring program. The discussion in these sections assumes a familiarity
with EPA's ACL guidance document, Part I, Information Required in ACL
Demonstrations. The discussion also assumes a familiarity with information in the
RCRA Part B permit application and the ground-water monitoring report, submitted
as part of the permit modification package for this facility. Data that appear in that
document are not reproduced in this application unless they are deemed necessary
for the sake of clarity and continuity. Appendix A contains a cross reference
between the ACL regulatory criteria and this application. Appendix B contains
chemical and physical properties and information from the Integrated Risk
Information System (IRIS) Data Base for the five constituents detected.
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3.0 IDENTIFICATION OF CONSTITUENTS
3.1 Hazardous Constituents in the Waste
The secure landfill cells are used for disposal of a variety of petroleum refinery
waste products. Table 3-1 presents a list of Appendix IX hazardous constituents
known to be contained in this landfill.
3.2 Extent and Degree of Contamination
Detection monitoring in the ground water downgradient of the secure landfill
initially detected statistically significant increases in concentrations of two indicator
parameters: total organic carbon and trichloroethylene. Facility D immediately
sampled the ground water in all of the monitoring wells and analyzed the sampfes
for all the constituents listed in Appendix IX of Part 264. The monitoring well
locations are shown in Figure 3-1. The wells shown in this figure are all well clusters,
with separate wells drilled to monitor the different aquifer units.
The Appendix IX scan identified five hazardous constituents in the ground
water above background concentrations: 1,1-dichloroethylene, toluene, 1,1,1-
trichloroethane, trichloroethylene, and xylene. To date, contamination has been
detected only in the upper glacial tills in three wells immediately downgradient of
the landfill cells. These wells, SP-3, SP-7, and G-14, combined with newly installed
wells C-1 through C-7, form the point of compliance (POC) for the six landfill cells.
Table 3-2 summarizes the recent ground-water monitoring data for hazardous
constituents at wells SP-3, SP-7 and G-14. The table presents maximum
concentrations of the five hazardous constituents observed in the three wells.
Complete monitoring and analysis data are presented in the ground-water
monitoring report, submitted as part of the permit modification package.
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TABLE 3-1.
APPENDIX IX HAZARDOUS CONSTITUENTS
PRESENT IN THE LANDFILL
Dichloropropane
Dichloropropene
Diethyl phthalate
7,12-Oimethyl-benz(a)anthracene
2,4-Dimethylphenol
Dimethyl phthalate
4,6-Dinitro-o-cresol
2,4-Dinitrophenol
2,4-Dinitrotoluene
Di-n-octyl phthalate
1,4-Dioxane
Fluoranthene
Indeno (1,2,3-cd) pyrene
Lead
Mercury
Methapyriline
3-Methylcholanthrene
Methyl ethyl ketone
Naphthalene
Nickel
p-Nitroaniline
Nitrobenzene
4-Nitrophenol
Pentachlorophenol
Phenol
Selenium
Tetrachloroethanes
Tetrachloroethylenes
Toluene
Trichlorobenzenes
Trichloroethanes
Trichloroethene(Trichloroethylene)
Trichlorophenols
Xylene
Acetonitrile
Acrolein
Acrylonitrile
Aniline
Antimony
Arsenic
Benzene
Benzo (b) fluoranthene
Benzo (a) pyrene
Beryllium
Bis (2-chloroisopropyl) ether
Bis (2-ethylhexyl) phthalate
Butyl benzyl phthalate
Cadmium
Carbon disulfide
p-Chloro-m-cresol
Chlorobenzene
Chloroform
Chloromethane (Methyl chloride)
2-Chloronaphthalene
2-Chlorophenol
Chromium
Chrysene
Cresols (Cresyiic acid)
Cyanide
1,2-Dibromomethane
(Ethylene dibromide)
Di-n-butyl phthalate
Dichlorobenzenes
1,2-Dichloroethane
trans-1,2-Dichloroethane
1,1-Dichloroethylene
Dichloromethane
(Methylene chloride)
2,4-Dtchlorophenol
3-2
-------
• G-8
G-6
• G-9
• B-42
• G-11
DB-512*
• G-2V
I G-12»
L.
SP-3
» C"2
C-1
»Z-13
5-19
• G-22 G-23»
• G-25
FACILITY D
PROPERTY BOUNDARY
LEGEND
• MONITORING WELL CLUSTERS
0 500 1000 1500
Scale, Feet
I
1
m
SO
FIGURE 3-1. LOCATION OF MONITORING WELL CLUSTERS
o
o
-------
OSWER Directive 9481.00-11
TABLE 3-2.
MAXIMUM CONCENTRATIONS OF HAZARDOUS CONSTITUENTS
OBSERVED IN THE GROUND WATER NEAR THE LANDFILL
Constituent
1,1-Dichloroethylene
Toluene
1,1,1 -Trich Soroethane
Trichloroethylene
Xylene
; Detection
Limit (ug/0
1
5
5
1
5
Maximum Concentration
Observed (ug/l)a
SP-3
BD
120
BD
4
450
SP-7
5
BD
26
3D
BD
G-14
BD
BD
BD
3
3D
BD - Below detection limit.
a In monitoring wells screened in the upper glacial till at POC.
Ground-water samples from the. lower strata have not shown
elevated levels of any hazardous constituents.
3-4
-------
OW5ER Directive 9481.00-11
4.0 GENERAL INFORMATION
This section describes some of the general characteristics of the facility that
pertain to the ACL application, including land use, water uses, and precipitation.
4.1 Land Use
Facility D is on an 850-acre site located in an industrial area in the northeast
United States. Figure 4-1 shows the current land uses in the area surrounding
Facility D. Roughly forty percent of the land within a one-mile radius of the landfill
is facility property, and a large portion of the remainder belongs to neighboring
industrial facilities. The only other land uses within the one-mile radius are
commercial and open space. There are no private residences within a one-mile
radius, but there are residences and agricultural lands within three miles.
The nearest town is Community A, 1.6 miles northwest. Community B lies 2
miles to the northeast. There is currently no agricultural use of the lands within a
mile of the landfill, but some lands beyond one mile and to the northeast are used
as pasture and for the cultivation of feed grasses.
4.2 Water Use and Users
The drinking water in the region is provided by surface water reservoirs and
distributed by a public water system. All domestic and industrial use water is
provided by the public water system. The ground water in the glaciolacustrine
silt/sand (GSS) aquifer is somewhat saline (mean TDS of 200 mg/L), and is lower in
quality than the water distributed by the public water system, but it is well within
Federal and State drinking water quality standards.
The State in which Facility D is located follows a "reasonable use" system of
ground-water allocation. All state residents are entitled to ground-water use.
Permits are required for well drilling and the State keeps an inventory of permitted
wells.
4-1
-------
NJ
RESIDENTIAL
APPROXIMATE 1 MILE
RADIUS FROM NW
BOUNDARY OF
LANDFILL
RESIDENTIAL
AND
COMMERCIAL
0 1000 2000
ssia=
Scale. Feet
3000
FACILITY D
BOUNDARY
m
7)
LEGEND
• IW-2 INDUSTRIAL WELL
FIGURE 4-1. LAND USES
o
9
-------
OWSER Directive 9*81.00-11
Although there are no private wells within a three-mile radius of the facility,
there are industrial wells in the vicinity of Facility D that pump water from the GSS
aquifer. This water is used for cooling and industrial cleaning purposes only. Figure
4-1 shows the location of these wells, and Table 4-1 describes their pertinent usage
characteristics.
TABLE 4-1.
INVENTORY OF WELLS WITHIN ONE MILE OF THE FACILITY
Well
IW-1
IW-2
IW-3
Aquifer
GSSb
GSS
GSS
Casing
elevation
(ft, MSL)
319
319
315
Well
Depth
(ft)
45
45
40
Depth
to Water
(ft)
16
16
15
Use*
Cooling & Cleaning
Cooling & Cleaning
Cooling
4.3
All uses listed are industrial.
GSS = Glaciolacustrine silt/sand.
Precipitation
Precipitation data is collected at a National Oceanographic and Atmospheric
Administration (NOAA) weather station five miles northeast of the facility.
Precipitation is distributed uniformly throughout the year. The wettest month is
August, which accounts for approximately 9 percent of the total annual
precipitation. Precipitation in this region exceeds evaporation by approximately 10
inches per year.
4-3
-------
OSWER Directive 9*81 JO-' '
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION
Facility D lies on a glacial plain near one of the Great Lakes. The Plain has a
gentle slope of approximately 0.3 percent toward the north. Figure 5-1 shows the
topography of the area between the facility and the lake.
5.1 Regional Geology
The bedrock units in this region are comprised of a series of shales, limestones
and dolostones. The rock units are relatively flat, lying with a regional dip of
approximately 0.75 percent to the south-southwest. The bedrock is overlain by
unconsolidated materials consisting of glacial deposits from several major periods
of glaciation overlain by recent alluvium.
The major drainage direction in the region is to the north, toward the lake.
On a local scale lakes, streams, bogs and ponds dot the irregular surface of the
glacial deposits. In some areas the glacial deposits have been reworked by streams.
The glacial units constitute the highest yield aquifer within the region;
however, ground water is available from bedrock aquifers in areas where the
unconsolidated deposits are absent, thin, or poorly permeable.
5.2 Site Geology
The geology of the site area has been characterized by extensive information
gathered during several field investigations. More than 450 borings and test pits
from several site studies were used in the Part B permit application to describe the
geology of the area. These are discussed in detail in the Part B permit application,
Section II. Locations of geologic cross sections are presented on Figure 5-2. Figure 5-
3 shows the generalized site stratigraphy utilizing a northwest-southeast cross
section (A-A'), and a west to east cross section through the landfill (B-B').
5-1
-------
OWSER Directive 9481.00-11
GREAT LAKE
LEGEND
ELEVATION (fsat, MSL)
FIGURE 5-1. REGIONAL TOPOGRAPHY
5-2
-------
en
I
UJ
FACILITY D
PROPERTY BOUNDARY
LEGEND
• MONITORING WELL CLUSTERS
0 500 1000 1500
Scale. Feet
o
on
m
30
O
FIGURE 5-2. LOCATION OF GEOLOGIC CROSS SECTIONS
O
o
-------
OSWER Directive 9481.00-11
NORTHWEST
ELEVATION
PCETMSL A
320 -] BOREHOLE
c-a
300-
280-
260-
240-
220 -J
UPPER
ALLUVIUM
WATER
TABLE
SOUTHEAST
A'
BOREHOLE
G-1
GLACJOLACUSTRINE CLAY
• GLACIOLACUSTRINE SILT/SANO
•BASAL RED TILL
HIGHLY WEATHERED FRACTURED SHALE
PARTIALLY WEATHERED SHALE BEDROCK
CROSS SECTION A-A'
ELEVATION
FEETMSL
r- 320
- 300
_ 280
- 260
- 240
I—220
ELEVATION
FEETMSL
320-1
300-
280-
260-
240-
220-
200—1
WEST
B ?ABLEER 8°R^°LE
BOREHOLE \ BOREHOLE
G-21 X
i*~-
GLACIOLACUSTRINE
CLAY
ELEVATION
FEET MSL
r- 320
- 300
- 280
r- 260
GLACIOLACUSTRINE
SILT/SANO
BASAL RED TILL
HIGHLY WEATHERED FRACTURED SHALE
-PARTIALLY WEATHERED SHALE BEDROCK
CROSS SECTION B-B'
0 500 TOOO 2000
HORIZONTAL SCALE IN FEET
VERTICAL EXAGGERATION, SO TIMES
FIGURE 5-3. GENERALIZED SITE STRATIGRAPHY
- 240
- 220
>- 200
5-4
-------
en
i
in
L.
1
31A
LEGEND
—— WATER TABLE CONTOUR (feel, MSL)
•+ FLOW DIRECTION
• TEST WELL
G-1
/ FACILITY D
/ PROPERTY
? BOUNDARY
I
O
i/i
m
2Q
O
0 500 1000 1500
Scale, Feet
O
o
FIGURE 5-4. UPPER TILL WATER TABLE CONTOURS
-------
OSWER Directive 9481.00-11
5.3 Ground-Water Hydrology
Shallow ground water occurs in the upper till at a depth of approximately 3 to
5 feet. Water table contours in the upper till, as shown in Figure 5-4, indicate that
the shallow ground water moves horizontally to the north-northwest. Vertical flow
in the upper till is low due to the underlying less permeable glaciolacustrine clay.
The glaciolacustrine clay is the main retarding layer to vertical flow in the site
area. Downward vertical gradients across the unit range from 0.1 to 0.58 with a
mean of 0.35.
Flow m the GSS (glaciolacustrine silt/sand) aquifer is essentially horizontal to
the north and west. The most transmissive portion of the aquifer is its thickest
portion, where a coarser sub-unit is present. As the ground water flows northward,
,-i-
it moves toward the areas of higher transmissivity.
Flow within the basal red till is controlled by pressure differences within the
GSS aquifer and the underlying bedrock. The shallow bedrock exhibits flow that is
predominantly horizontal toward the north and west, similar to flow in the GSS
aquifer. The shallow bedrock has a low hydraulic conductivity and is not a
significant regional aquifer. The values for hydraulic conductivity are 1 x 10-5
cm/sec in the shallow rock and 5x10-6 cm/sec in the deeper rock zones. Table 5-1
gives the permeability and the hydraulic gradient for the major hydrogeologic
units.
5-6
-------
OSWER Directive 9481.00-11
TABLE 5-1.
MEASURED PERMEABILITY AND HYDRAULIC GRADIENT
Geologica
Formation(a)
UT
GC
MST
GSS
BRT
SB
Permeability, K
(cm/s)
Horizontal
2x10-6
5x10-8
3x10-6
2x10-*(e)
4x10-8
1x10-5
Vertical
6x10-7(0
2x10-8
1x10-7
2x10-4(e)
3x10-8
-
Gradient, i
(ft/ft)
Horizontal(b)
0.002
0.001
0.005
0.007
0.004
0.004
Vertical
0.012
0.35
0.007(d)
6x10-6(d)
0.04
-
Notes:
(a) Formations
UT-Upper Till
GC - Glaciolacustrine Clay
MST-Middle Si It Til I
GSS - Glaciolacustrine Silt/Sand
BRT-Basal Red Till
SB-ShallowBedrock
(b) Exit gradient from property.
(c) Kv = 6x10-7 cm/s due to structural discontinuities.
(d) Estimated to maintain continuity.
(e) Coarse portion of aquifer with Kv = KH-
5-7
-------
OSWER Directive 9481 00-11
6.0 EXPOSURE PATHWAYS
This section reviews the various pathways by which contaminants released
from Facility D may threaten human health and the environment. The exposure
pathways are discussed and the maximum allowable concentration for each
constituent is determined for the designated receptor.
The policy described in Part I of the ACL Guidance Document states that all
facilities with RCRA permitted units that have contaminant plumes in useable
ground water should prevent these plumes from expanding and contaminating
more ground water. Since Facility D is a RCRA unit that has contaminated useable
ground water, it should follow the above policy. Therefore, for this application, the
point of exposure (POE) is assumed to be the same as the point of compliance (POC).
6.1 Potential Human Exposure -
Although the water from the upper till (water table aquifer) is of relatively
poor quality, its use is not restricted. All water quality parameters are within
Federal and State drinking water standards and the aquifer was used as a source of
drinking water prior to 1950. As discussed above, the POE equals the POC. Human
exposure at the POC/POE may take the form of drinking water exposure, dermal
exposure, industrial exposure, or agricultural exposure. Agricultural exposure is
ruled out as the lands near the POC/POE are not suitable for agriculture. Dermal
exposure is not well understood, and to date, effects from this type of exposure are
not easily quantifiable. Contaminant doses from industrial exposure would not be
expected to exceed those from daily exposure to contaminated drinking water.
Therefore, a hypothetical residential drinking water well that draws water at the
POC/POE will be used to determine the maximum allowable concentrations for
human exposure in this application.
6.2 Potential Environmental Exposure
The only environmental exposure that potentially could occur is through
contaminated ground water discharging into the Great Lake. The Great Lake is
approximately four miles north of Facility D. Because of the low contaminant
6-1
-------
OSWER Directive 9481 00-11
concentrations and the distance to the lake (i.e., human exposure levels set four
miles upgradient of potential ecosystem exposure), any significant environmental
exposures to the contaminants is extremely unlikely to occur
6.3 Maximum Allowable Exposure Concentrations
•r
The analysis of the potential exposure pathways in 6.1 and 6.2 demonstrates
that only human exposure potential exists. Thus, maximum allowable exposure
concentrations for human exposure will be used to determine the ACLs. The five
constituents addressed in this application are all known human health hazards.
Two of them (trichloroethylene and 1,1-dichloroethylene) have been identified as
suspected human carcinogens and four (1,1,1-trichloroethane, 1,1-
dichloroethylene, xylene, and toluene) have been identified as systemic toxicants
(EPA, 1987b). Maximum contaminant levels (MCLs) under the National Primary
Drinking Water Regulations have been established for 1,1-dichloroethylene, 1,1,1-
trichloroethane, and trichloroethylene (EPA, 1987c).
In order to derive allowable exposure concentrations for those constituents
(toluene and xylene) that do not have MCLs, this application uses reference doses
(RfDs) developed for toluene and xylene by the EPA's Environmental Criteria and
Assessment Office (EPA, 1986). Standard drinking water exposure assumptions of a
70 kg adult consuming two liters of water per day are used to calculate maximum
allowable exposure concentrations using the following equation:
C = RfD x 70 kg (6-1)
21
where C = exposure concentration, mg/l
RfD = reference dose, mg/kg/day
70 = average adult weight, kg
2 = water intake, I/day.
The maximum allowable exposure concentrations from Equation 6-1 for
xylene and toluene are listed in Table 6-1. Also listed are the MCLs for 1,1-
dichloroethylene, 1,1,1-trichloroethane, and trichloroethylene. These five
concentrations will be used as the proposed ACLs.
6-2
-------
OSWER Directive 9481.00-11
TABLE 6-1.
MAXIMUM ALLOWABLE EXPOSURE CONCENTRATIONS
Constituent
1,1-
Dichloroethylene
Toluene
1.1,1-
Trichloroethane
Trichloroethylene
Xylene
RfD
(mg/kg/day)
NA
0.3
NA
NA
2.0
Maximum Allowable
Concentration (mg/l)
0.007(i]
10 [21
0.20m
0.005(1]
70 (21
NA - Not applicable.
in - Maximum Contaminant Level under the National Primary
Drinking Water Regulations.
(21 - Based on Equation 6-1.
6-3
-------
OSWER Directive 9481.00-11
7.0 DEVELOPMENT OF ACLs
This section presents the alternate concentration limits (ACLs) proposed in this
application and summarizes the procedures used in developing the ACLs. The ACLs
are based on the maximum allowable concentrations developed in Section 6 of this
application.
*
Alternate concentration limits for this application are based on human
exposure to drinking water at the POOPOE. ACLs for the five contaminants are
based on their allowable human health exposure levels. These exposure levels are
MCLs for 1,1-dichloroethylene, 1,1,1-trichloroethane, and trichloroethylene, and
maximum exposure concentrations derived from RfDs for toluene and xylene. Table
7-1 gives the maximum allowable concentrations and ACLs for the five ground-
water contaminants. ACLs are set at the same levels as the maximum allowable
concentrations for the contaminants.
The proposed ACLs are based on the following practices and assumptions: (1)
Facility 0 received its RCRA permit approximately 2 years ago; no contamination in
the ground water above background was detected at that time; (2) five
contaminants have recently been detected in the ground water at the compliance
point; the contaminant plume does not extend an appreciable distance past the
POC; (3) these conditions indicate that Facility D meets the conditions of Case 1 of
the ACL Guidance Document (EPA, 1987a); the POE should be set at the POC; (4) for
the ACL demonstration, the principal exposure pathway is assumed to be human
exposure to drinking water at a hypothetical well located at the POC/POE; (5) the
maximum allowable concentrations are calculated assuming daily exposure to
contaminated drinking water; and MCLs take precedence over other calculated
maximum exposure concentrations; and (6) because the POE is at the POC, the
proposed ACLs are set at the same levels as the maximum allowable concentrations
for each contaminant.
7-1
-------
OSWER Directive 9481.00-11
TABLE 7-1.
PROPOSED ALTERNATE CONCENTRATION LIMITS
Constituent
1,1-Dichloroethylene
Toluene
1,1,1-
Trichloroethane
Trichloroethylene
Xylene
Carcinogen
X
X
Systemic
Toxicant
X
X
X
X
Maximum
Observed
Concentration
(mg/0-
5. Ox 10-3
1.2x10-1
2.6x10-2
4.0x10-3
4.5x10-1
Maximum
Allowable
Concentration
(mg/l)
7.0x10-3
10
2.0 x 10-1
5.0x10-3
70.0
Proposed
Alternate
Concentration
Limit (mg/l)
7.0 x 10-3
10
2.0 x 10-1
5.0x10-3
70.0
* From Table 3-2.
7-2
-------
OSWER Directive 9431 CO-1)
8.0 GROUND-WATER MONITORING PROGRAM
Ground water will be monitored quarterly at the POC (wells SP-3, SP-7, G-14,
and C-1 through C-7) for the five hazardous constituents detected and annually for
all Appendix IX constituents as required in the compliance monitoring program
under 40 CFR 264.99. The groufld-water flow rate and direction will also be
determined annually for the active life of the landfill area (including the closure
period).
If additional hazardous constituents are found, or if concentrations exceed the
ACLs, Facility D will report the concentrations to the Regional Administrator within
seven days of completion of the analysis. If the increase is statistically significant for
any of the five constituents, Facility D will notify the Regional Administration within
seven days of the concentration limits that have been exceeded and, within- 180
days, submit an application for a permit modification to establish a corrective action
program.
8-1
-------
OSWER Directive 9481 00-1 i
REFERENCES
EPA (U.S. Environmental Protection Agency), 1986. Research and Development.
Verified Reference Doses (RfDs) of the U.S. EPA, ECAO-CIN-475,
EnvironmentalCriteria and Assessment Office, Cincinnati, Ohio, January.
EPA (U.S. Environmental Protection Agency), 1987a. Alternate Concentration Limit
Guidance, Part 1, ACL Policy and Information Requirements. EPA/530-SW-87-
017, OSWER, Washington, D.C.July.
EPA (U.S. Environmental Protection Agency), 1987b. Integrated Risk Information
System: Chemical Files, EPA/600-8-86-032, OHEA, Washington, D.C. March,
EPA (U.S. Environmental Protection Agency), 1987c. "National Primary Drinking
Water Regulations - Synthetic Organic Chemicals; Final Rule," Federal
Register, 52:25690, July 8,1987.
Other Resource Documents
U.S. Environmental Protection Agency, "Preamble - Section D: Ground-Water
Protection." Federal Register. 47:33292. July 26. 1982.
U.S. Environmental Protection Agency, "Proposed Guidelines for Health Risk
Assessment of Chemical Mixtures," Federal Register, 50:1170-1176, January
9,1985.
R-1
-------
OSWER Directive 9481.00-11
APPENDIX A
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
A-1
-------
OSWER Directive 9481.00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
Criteria for Assessing Potential Adverse Effects on . r, r _eo 0 .
Ground-Water Quality: Jfii £? y
§264.94(b)(1) Sectlon No
(i) The physical and chemical characteristics of the 3.1,3.2
waste in the regulated unit, including its
potential for migration;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3
facility and surrounding land;
(iii) The quantity of ground water and the direction 5.3
of ground-water flow;
(iv) The proximity and withdrawal rates of ground- 4.2
water users;
(v) The current and future uses of ground water in 4.1,4.2
the area;
(vi) The existing quality of ground water, including 3.2
other sources of contamination and their
cumulative impact on the ground-water
quality;
(vii) The potential for health risks caused by human 6.1,6.3
exposure to waste constituents;
(viii) The potential damage to wildlife, crops, 6.2,6.3
vegetation, and physical structures caused by
exposure to waste constituents;
(ix) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects;
A-2
-------
OSWER Directive 9481.00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
(Continued)
Criteria for Assessing Potential Adverse Effects on An r ctudv
Hydraulically-Connected Surface-Water Quality: s^tinn No
§264.94(b){2) beaion N0-
(i) The volume and physical and chemical 3.1,3.2
characteristics of the waste in the regulated
unit;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3,5.4
facility andsurrounding land;
(iii) The quantity and quality of ground water, and 5.3,5.4
the direction of ground-water flow;
(iv) The patterns of rainfall in the region; 4.3
(v) The proximity of the regulated unit to surface 4.2
waters;
(vi) The current and future uses of surface waters in 4.1,4.2
the area and any water quality standards
established for those surface waters;
(vii) The existing quality of surface water, including 3.2
other sources of contamination and the
cumulative impact on surface water quality;
(viii) The potential for health risks caused by human 6.1, 6.3
exposure to waste constituents;
(ix) The potential damage to wildlife, crops, 6.2, 6.3
vegetation, and physical structures caused by
exposure to waste constituents; and
(x) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects.
A-3
-------
OSWER Directive 9481 00-11
APPENDIX B
CHEMICAL AND PHYSICAL PROPERTIES1 AND IRIS (INTEGRATED
RISK INFORMATION SYSTEM) DATA BASE FOR 1,1-DICHLOROETHYLENE,
TOLUENE, 1,1.1-TRICHLOROETHANE. TRICHLOROETHYLENE, AND XYLENE
1 Adapted from: Chemical, Physical and Biological Properties of Compounds Present
at Hazardous Waste Sites. Final Report, Office of Waste Programs Enforcement
(OWPE) and Office of Solid Waste and Emergency Response (OSWER), U.S. EPA,
September 27,1985.
B-1
-------
OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
1,1-DICHLOROETHYLENE
Summary
CAS Number: 75-35-4
Chemical Formula: CH2C£l2
IDPACName: 1,1-Dichloroethene
Important Synonyms and Trade Names: Vinylidene chloride, VDC,
1,1-dichloroethene, 1,1-DCE
Chemical and Physical Properties
Atomic Weight: 96.94
Boiling Point: 37°C
Melting Point: -122.1°C
Specific Gravity: 1.218at20°C
Solubility in Water: 400 mg/liter at 20°C
Solubility in Organics: Sparingly soluble in alcohol, ether, acetone, benzene,
and chloroform
Vapor Pressure: 500 mmHg at 20°C
Vapor Density: 3.25
Log Octanol/Water Partition Coefficient: 1.48
B-2
-------
OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (lRIS):Chemical Files
1,1-Dichloroethylene; CAS No. 75-35-4 (Revised 11/16/1986)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only
after a comprehensive review of ctUonic toxicity data by work groups
composed of U.S. EPA scientists from several Agency Program Offices. The
summaries presented in Sections-1 and II represent a consensus reached in
those reviews. The conceptual bases of these risk assessments are described
in Appendices A & B in Service Code 4. The other sections are supplementary
information which may be useful in particular risk management situations, but
have not yet undergone comprehensive U.S. EPA review. The risk management
numbers (Section V) may not be based on the most current risk assessment, or
may be based on a current, but unreviewed, risk assessment, and may take into
account factors other than health effects (e.g., treatment technology). When
considering the use of risk management numbers for a particular situation,
note the date of their development, the date of the most recent risk
assessment, and whether technological factors were considered. For a more
detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR 1,1 -Dichloroethylene
I. Chronic Systemic Toxicity: Noncarcinogenic Health Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
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OSWER Directive 9481 00-11
assessment information pertaining to the carcinogenicity of this compound Please
refer to the Background Document on the Rf D (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: 1,1-Dichloroethylene (Vinylidene Chloride)
CAS No.: 75-35-4 ' Preparation Date 04/17/86
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Hepatic lesions NOAEL: None 1000 1 9E-3
mg/kg/day
Rat chronic oral LOAEL: 9 mg/kg/day
bioassay
Quart eta I. (1983)
* Dose Conversion Factors & Assumptions: none
2. PRINCIPAL AND SUPPORTING STUDIES
Quast, J.F., C.G. Humiston. C.E.Wade, etal. 1983. A chronic toxicity
andoncogenicity study in rats and subchronic toxicity study in dogs on ingested
vinylidene chloride. Fund. Appl. Toxicol. 3:55-62.
Groups of 48 each, male and female, Sprague-Dawley rats (Spartan substrain)
were administered 50,100or200ppm 1,1-dichloroethylene in drinking water for a
period of 2 years. Control groups of 80 animals/sex were maintained for the same
period. Daily intake was calculated by the authors to be 7, 10 or 20 mg/kg bw/day
for males and 9,14 or 30 mg/kg bw/day for females. There were no treatment-
related effects on mortality, body or organ weight, clinical chemistry, urinalysis,
hematology or numbers of tumors. The only pathological findings were of hepatic
lesions, generally characterized by minimal mid-zonal hepatocellular fatty change,
and hepatocellular swelling. These were noted in rats of all female treatment
groups. In male rats only the 200 ppm treatment group showed a statistically
significant increase in incidence of hepatocellular swelling, but this trend was also
observed in animals receiving 100 ppm 1,1-dichloroethylene.
As part of this same study, beagle dogs (4/sex/group) were administered 6.25,
12.5 or 25 mg/kg bw/day in gelatin capsules. Treatment for 97 days had no effect.
This study, as well as a review of the available data, indicate that the liver is the
most sensitive target organ and rats are the most sensitive species. The drinking
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OSWER Directive 9481.00-11
water exposure reported byQuastetal. (1983) offers a more suitable model for
potential human exposure to 1,1-dichloroethylene than does the NTP bioassay
wherein animals were gavaged. It is, therefore, appropriate to set an RfD based on
the LOAELof 9mg/kg bw/day for hepatic lesions in female rats.
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 1000. A factor of 10 each was used for use of a LOAEL, for interspecies
variation, and for protection of sensitive human subpopulations.
MF = 1
4. ADDITIONAL COMMENTS
1,1-Dichloroethylene has been shown to be fetotoxic, but notteratogenic
to rodents after exposure in drinking water or by inhalation (Short et al.,
1977; Murray etal., 1979).
5. CONFIDENCE IN THE RfD
Study: Medium Data Base: Medium RfD: Medium
The study by Quast et al. (1983) was conducted using appropriate numbers of
animals of two species, and measured several end points, and was of chronic
duration (rats). As there are corroborative chronic and subchronic oral bioassays,
confidence in the study, data base and RfD are considered medium.
6. DOCUMENTATION AND REVIEW
U.S. EPA. 1985. Drinking Water Criteria Document for 1,1-Dichloroethylene
(Vinylidene Chloride). Office of Drinking Water, Washington, DC.
This document has received a lengthy internal review and has undergone public
comments.
Agency RfD Work Group Review: 01/22/85
Verification Date: 01/22/85
7. U.S. EPA CONTACTS
Primary: P. Fenner-Crisp FTS/382-7589 or 202/382-7589
Office of Drinking Water
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OSWER Directive 9481.00-11
Secondary: M.L Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: 1,1-Dichloroethylene
CAS No.: 75-35-4
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: 1,1-Dichloroethylene (vinylidene chloride)
CAS No.: 75-35-4 Preparation Date: 02/19/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification: C, possible human carcinogen; based on tumors observed in one
mouse strain after inhalation exposure. Other studies were of
inadequate design. Vinylidene chloride is mutagenic and a
metabolite is known to alkylate and to bind covalently to DNA. It is
structurally related to the known human carcinogen, vinyl chloride.
1. HUMAN DATA
Inadequate. An epidemiologic study of 138 workers showed no carcinogenic
effect associated with vinylidene chloride exposure (Ott et al., 1976). Based on
power considerations, this study is inadequate for assessing cancer risk in humans.
2. ANIMAL DATA
Limited. Eighteen animal studies have been reported, which provide
information about the carcinogenic potential of vinylidene chloride. Eleven of the
studies involved inhalation exposure, five were oral, and one each was by skin
application and subcutaneous injection. Most were not designed for maximum
sensitivity to detect carcinogenic effects. None of the 11 inhalation exposures were
for lifetime; all were 12 months or less. Three of the five oral studies were lifetime
exposure. Of all the studies, only one inhalation study produced a response as a
complete carcinogen.
In the inhalation study by Maltoni et al. (1985) both sexes of Swiss mice were
exposed 10 and 25 ppm (MTD) for 4-5 days/week for 12 months. A statistically
significant increase in kidney adenocarcinoma was noted in male mice. Although
statistically significant increases in mammary carcinomas in female mice and
pulmonary adenomas in both sexes were reported, dose-response relationships
were unclear. A second Maltoni study exposed Sprague-Dawley rats to 10, 25, 50,
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OSWER Directive 9481.00-11
100 or 150 ppm, 4-5 days/week for 12 months and observed them until spontaneous
death. A statistically significant increase in total mammary tumors, but not
carcinomas alone, was seen only at 10 and 100 ppm. Nodose-response relationship
was apparent and the overall interpretation of the mammary tumor incidence is
inconclusive.
Four gavage studies (in rats and mice) and one drinking water study in rats
have been negative (Maltoni etal., 1985; Quastetal., 1983; Humiston etal., 1978;
NCI/NTP, 1982; Ponomarkov and "Tomatis, 1980). Only the NCI/NTP (1982) corn oil
gavage study in Fischer 344 rats and female B6C3F1 mice and the drinking water
study in Sprague-Dawley rats undertaken for drinking water study did not achieve a
maximum dose of metabolite. All to detect a response.
Vinylidene chloride did not act as a complete carcinogen when applied
topically or s.c. to ICR/Ha mice but did serve as an initiator when followed by
phorbol myristate acetate treatment (van Duuren et al., 1980).
3. SUPPORTING DATA
Vinylidene chloride has been shown to be mutagenic for Salmonella typhi-
murium in multiple assays. This activity is largely dependent on the pres-
ence of microsomal enzymes. It has been used as a positive control in
studies of chemicals that are gases in or near room temperature. Both con-
ventional and host-mediatedassays of Saccharomyces cerevisiae have been
positive for mitotic gene conversion (Bronzetti et al., 1981). Vinylidene
chloride was not mutagenic for V79 cells exposed to vapor in vitro (Drevon
and Kuroki, 1979), nor did it produce chromosomal aberrations in bone marrow
cells of ICR mice given single or repeated i.p. treatment in vivo (Cerna and
Kypenova, 1977). CD-1 mice and Sprague-Dawley rats treated in vivo with
labeled Vinylidene chloride showed evidence of DNA alkylation and subsequent
repair whicn was specific to liver and kidney. Kidney in rat and mouse had
higher alkylation than liver (Reitz etal., 1980). Covalent binding of VC. closely
correlates with metabolite formation. McKenna etal. (1977) observed greater
binding in kidney than liver and mouse binding was greater than rat. Vinylidene
chloride failed to induce dominant lethal mutations in mice (Anderson et al., 1977)
or rats (Short et al., 1977). Vinylidene chloride is structurally related to the known
carcinogen, vinyl chloride.
B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 0.6/mg/kg/day
1. UNIT RISK SUMMARYTABLE
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/L)
6ug/L 6E-1 ug/L 6E-2 ug/L 1.7E-5 LM, extra risk
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2. DOSE-RESPONSE DATA
Species/Strain -Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Rat, F344, male;
adrenal
pheochromocytomas
*
mg/kg/day
0
0.71
3.57
mg/kg/day
0
0.120
0.603
6/50
5/48
13/47
NCI/NTP,
1982
Human equivalent doses were determined by adjusting the administered
animal dose by the cube root of the ratio of the weight of the animal (estimated
0.43 kg) to human weight (70 kg), and adjusting for length of exposure and length
of the experiment.
The unit risk estimate chosen was the highest of four slope factors calculated
from two studies that did not show a statistically significant increase in tumor
incidence attributable to oral exposure of vinylidene chloride. The drinking water
study in rats(Quastetal., 1983) produced the lowest slope factor of 0.2/mg/kg/day.
The highest slope factor (0.6/mg/ kg/day) was based on male rat adrenal tumors
from NCI/NTP (1982). Use of data from this study wherein there were no statistically
significant increases in tumor incidence appears justified as the slope factor derived
is within a factor of 2 of the slope factor based on data from the inhalation study of
Maltonietal. (1977,1985).
3. ADDITIONAL COMMENTS
Animal pharmacokinetic data show that metabolite elimination is dose-
dependent and saturable at inhalation concentrations of 150-200 ppm, or
approximately 50 mq/kg oral ingestion. Vinylidene chloride is rapidly absorbed, has
limited solubility and is not stored in body tissues. None of the available bioassays
have totally adequate design given the pharmacokinetic and metabolism data. The
positive Maltoni inhalation study comes closest to achieving a maximum dose of
metabolite, albeit less than lifetime exposure, but less than maximum dosing vis-a-
vis metabolites. The water unit risk based on incidence data from a drinking water
study was chosen because of the appropriate route of administration to oral risk
estimation.
The unit risk should not be used if the water concentration exceeds 6E + 2 ug/L,
since above this concentration the slope factor may differ from that stated.
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OSWER Directive 9481.00-11
4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE ESTIMATE
The confidence that the upper limit is not greater than 0.6/mg/kg/day is high
since it is the largest value by a factor of 3 from four rat data sets in two studies. If
drinking water alone is considered they might be reduced by a factor of 3. Overall
confidence, however, in an estimate based on negative animal data is rated low.
The slope factors for the oral guantitative estimate based on inhalation and
based on the negative oral data are within a factor of 2.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
C. INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 1.2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
2ug/cu.m 2E-1 ug/cu.m 2E-2 ug/cu.m 5.0E-5 LM, extra
risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Mouse/Swiss, male; Route: Inhalation Maltoniet
kidney adenocar- al, 1977.
cinoma 1935
ppm mg/kg/day
0 0 0/56
0 0 0/70
10 0.078 0/25
25 0.195 3/21
25 0.195 25/98
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OSWER Directive 9481.00-11
3. ADDITIONAL COMMENTS
Within each dose pair there were not statistically significant differences between
incidences in the two control and the 25 ppm groups. Human equivalent doses
were determined assuming 0.035 kg as the average weight of the male mice,
adjusting for continuous lifetime exposure in the mice, accounting for metabolism
and pharmacokinetics for mice and using 70 kg with 1.85 sq.m surface area for
humans (U.S. EPA, 1985).
The unit risk should not be used if the air concentration exceeds 2E + 2
ug/cu.m, since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
Sufficient numbers of animals were used for treatment and controls. Only two
dose points provided data suitable for quantitation. Confidence is low that the
upper limit estimate is predictive of low exposure risk.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
D. DOCUMENTATION AND REVIEW
1. REFERENCES
U.S. EPA. 1985. Health Assessment Document for Vinylidene Chloride. Prepared by
the Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Research Triangle Park, NC. EPA 600/8-83-031F.
Maltoni, C, G. Lefemine, P. Chieco, et al. 1985. Experimental research on vinylidene
chloride carcinogenesis. In: Archives of Research on Industrial Carcinpgenesis, Vol.
3, C. Maltoni and M. Mehlman, Ed. Princeton Scientific Publishers, Princeton, NJ.
2. REVIEW
The values in the 1985 Health Assessment Document for Vinylidene Chloride
received extensive peer and public review.
Agency Work Group Review: 12/04/86, 01/07/87
Verification Date: 01/07/87
3. U.S. EPA CONTACTS
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OSWER Directive 9481.00-11
Primary: J.C. Parker 303/293-1789 or FTS/564-1789
Office of Research and Development
Secondary: S. Bayard 202/382-5722 or FTS/382-5722
Office of Research and Development
III. DRINKING WATER HEALTH. ADVISORIES
Chemical: 1,1-Dichloroethylene
CAS No.: 75-35-4
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical: 1,1-Dichloroethylene
CAS No.: 75-35-4 Preparation Date: 09/30/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
A. RISK MANAGEMENT ACTIONS
Risk Status Risk Considers
Management Management Econ/Tech
Action Date Value Feasibility Reference
Reportable Statutory 50001bs no 50 FR 13456
Quantity (RQ) 1980 04/04/85
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OSWER Directive 9481.00-11
Water Quality
Criteria (WQC):
a. Human Health Final 0.033 ug/l no 45 FR 79318
1980 11/28/80
b. Aquatic Toxicity
1) Freshwater Final Acute no ibid.
1980 11,600 ug/l (LEL)
Chronic
none
2) Marine Final Acute no ibid.
1980 224,000 ug/l (LEL)
Chronic
none
Clean Air Act Current Decision not no 50 FR 32633
Regulatory 1985 to regulate 08/13/85
Decision
(NESHAPorNSPS)
B. RISK MANAGEMENT RATIONALE
RQ
The statutory RQ of 5000 pounds established under Section 311(b)(4) ofthe
Clean Water Act is retained until the assessment of potential carcinogenicity is
complete.
Contact: RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
WQC
Contact: Office of Water Regulations and Standards
202-382-5400 or FTS-382-5400
a. Human health: The WQC of 0.033 ug/l represents a cancer risk level of 1E-6,
based on consumption of contaminated organisms and water. A WQC of 1.85 ug/l
(cancer risk level of 1E-6) has also been established based on consumption of
contaminated organisms alone.
b. Aquatic toxicity: Water quality criteria for the protection of aquatic life are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The "(LEL)" after the value indicates that the minimum data were not
available and the concentration given is not a criteria value but the lowest effect
level found in the literature. Values given represent trihalomethanes as a class. No
specific chemicals were mentioned.
CAA Regulatory Decision
While there is some evidence of carcinogenicity (rare kidney tumors in one sex
of one strain of one species), EPA concluded tnat the overall weight of evidence was
not sufficient to warrant regulation as a carcinogen. Also, measured and modeled
ambient concentrations were well below any non-cancer health effects of concern.
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OSWER Directive 9481.00-11
Thus, EPA concluded that no regulation under the CAA of routine emissions was
warranted at the current time.
Contact: Chief, Pollutant Assessment Branch
919/541-5645 or FTS/629-5645
V. SUPPLEMENTARY DATA
Chemical: 1,1-Dichloroethylene
CAS No.: 75-35-4
Information is not available at this time.
Synonyms: ETHYLENE, 1.1-DICHLORO-; CHLORURE DE VINYLIDENE (French); 1,1-
DCE; 1,1-DICHLOROETHENE(9CI); 1,1-DICHlOROiTHYLENE; ETHENE, 1.1-
DICHLORO-; NCI-C54262; RCRA WASTE NUMBER U078; SCONATEX; VDC;
VINYLIDENE CHLORIDE; VINYLIDENE CHLORIDE (II); VINYLIDENE CHLORIDE
(ACG1H); VINYLIDENE DICHLORIDE; VINYLIDINE CHLORIDE; 1,1-
DICHLOROETHYLENE; ETHYLENE, 1,1-DICHLORO-(8CI); UN1303(DOT); VDC;
VINYLIDENE CHLORIDE, inhibited; VINYLIDENE CHLORIDE, inhibited (DOT)
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RESOURCE DOCUMENTS FOR 1,1,-DICHLOROETHYLENE
INTERNATIONAL AGENCY FOR RESEARCH ON CANCER (IARC) Monographs on the
Evaluation of Carcinogenic Risk of Chemicals to Humans, Vol. 19: Some
Monomers. Plastics and Synthetic Elastomers, and Acrolein, World Health
Organization, Lyon, France, 1979.
NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH. Registry of Toxic
Effects of Chemical Substances-Data Base. Washington, D.C., October, 1983.
NATIONAL TOXICOLOGY PROGRAM, Carcinoqenesis Bioassayof Vinylidene
Chloride (CAS No. 75-35-4) in F344 Rats and B6C3F Mice (Gavaqe Study). NTP
Technical Report Series No. 228, DHHS Publication No. (NIH) 82-1784,
Washington, D.C., 1982.
U.S. ENVIRONMENTAL PROTECTION AGENCY, Water-Related Environmental Fate of
129 Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December, 1979.
U.S. ENVIRONMENTAL PROTECTION AGENCY, Ambient Water Quality Criteria for
Dichloroethylenes, Office of Water Regulations and Standards, Criteria and
Standards Division, EPA/440-5-80-041, Washington, D.C., October, 1980.
U.S. ENVIRONMENTAL PROTECTION AGENCY, Health Effects Assessment for 1,1-
Dichloroethylene, Final Draft, Environmental Criteria and Assessment Office,
Cincinnati, Ohio, ECAO-CIN-H051, September, 1984.
U.S. ENVIRONMENTAL PROTECTION AGENCY, Health Assessment Document for
Chloroform. Office of Health and Environmental Assessment, EPA/600-8-84-
004F, Washington, D.C. September, 1985.
VERSCHUEREN, K., Handbook of Environmental Data on Organic Chemicals, Van
Nostrand Reinhold Co., New York, 1977, 659 pages.
WEAST, R.E., ed.f Handbook of Chemistry and Physics 62nd ed, CRC Press, Cleveland,
Ohio, 1981, 2,332 pages.
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CHEMICAL AND PHYSICAL PROPERTIES OF
TOLUENE
CAS Number: 108-88-3
«z
Chemical Formula: CeHsCHs
IDPACName: Methylbenzene
Important Synonyms and Trade Names: Toluol, phenylmethane, methylbenzene
Chemical and Physical Properties
Molecular Weight:
Boiling Point:
Melting Point:
Specific Gravity:
Solubility in Water:
Solubility in Organics:
Vapor Pressure:
Vapor Density:
Viscosity:
Flash Point:
92.13
110.6X
-95°C
0.8669 at 20°C
534.8 mg/liter
Soluble in acetone, ligroin, and carbon disulfide;
miscible with alcohol, ether, benzene, chloroform,
glacial acetic acid, and other organic solvents
28.7mmHgat25°C
3.14
0.625 centipoise at 15.6°C
4.4°C
Log Octanol/Water Partition Coefficient: 2.69
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OSWER Directive 9431.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Toluene; CAS No. 108-88-3 (Revised 11/16/1986)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic foxicity data by work groups composed or U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Toluene
I. .Chronic SystemicToxicity: Noncarcinogenic Health Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: none
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Toluene
CAS No.: 108-88-3 Preparation Date: 01/08/86
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Clinical chemistry 300 ppm (1130 mg/cu. 100 1 3E-1
and hematological m) converted to 29 mg/kg/day
parameters mg/kg/day (NOAEL)
Rat chronic inha- LOAEL: None
lation study
CUT (1980)
* Dose Conversion Factors & Assumptions: 5 days/7 days, 6 hours/24 hours;
0.5 absorption factor, 20 cu.m human breathing rate; 70 kg; thus, 1130
mg/cu.m x 5 day/7 days x 6 hours/24 hours x 0.5 x 20 cu.m/day / 70 kg =
28.8 mg/kg/day
2. PRINCIPAL AND SUPPORTING STUDIES
CUT (Chemical Industry Institute of Toxicology). 1980. A 24-month inhalation
toxicology study in Fischer-344 rats exposed to atmospheric toluene. CUT, Research
Triangle Park, NC.
Toluene is most likely a potential source of respiratory hazard. The only
chronic toxicity study on toluene was conducted for 24 months in male and female
F344 rats (CUT, 1980). Toluene was administered by inhalation at 30,100 or 300
ppm (113, 377 or 1130 mg/cu.m) to 120 male and 120 female F344 rats for 6
hours/day, 5 days/week. The same number of animals (120 males and 120 females)
was used as a control. Clinical chemistry, hematology and urinalysis testing was
conducted at 18 and 24 months. All parameters measured at the termination of the
study were normal except for a dose-related reduction in hematocrit values in
females exposed to 100 and 300 ppm toluene.
Based on these findings, a NOAEL of 300 ppm or 1130 mg/cu.m was derived.
An oral RfD of 20 ma/day can be derived using route-to-route extrapolation. This
was done by expanding the exposure from 6 nours/day, 5 days/week to continuous
exposure and multiplying by 20 cu.m/day and 0.5 to reflect a 50% absorption factor.
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3. UNCERTAINTY AND MODIFYING FACTORS
UF = 100. An uncertainty, factor of 100 (10 for sensitive individuals and 10 for
intraspecies extrapolation) was also applied.
MF = 1
4. ADDITIONAL COMMENTS
The only oral study found in the data base (Wolf etal., 1956) contains
subchronic data in which no adverse effects of toluene were reported at the highest
dose tested (590 mg/kg/day).
5. CONFIDENCE IN THE RfD
Study: High Data Base: Medium RfD: Medium
Confidence in the critical study is high because a large number of animals/sex
were tested in each of three dose groups and many parameters were studied.
Interim kills were performed. The data base is rated medium because several
studies support the chosen effect level. The confidence of the RfD is not higher than
medium because the critical study was by the inhalation route.
6. DOCUMENTATION AND REVIEW
Limited Peer Review and Agency-wide Internal Review, 1984.
U.S. EPA. 1985. Drinking Water Criteria Document for Toluene. Office of
Drinking Water, Washington, DC.
Agency RfD Work Group Review: 05/20/85, 08/05/85,08/05/86
Verification Date: 05/20/85
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7. U.S. EPA CONTACTS
Primary: C.T. DeRosa FTS/684-7534 or 513/569-7534
Office of Research and Development
Secondary: M.L Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Toluene
CAS No.: 108-88-3
This chemical has not been evaluated by the U.S. EPA for evidence of human
carcinogenic potential.
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical: Toluene
CAS No.: 108-88-3 Preparation Date: 09/30/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in Sections I & II), as this may explain apparent inconsistencies. Also
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OSWER Directive 9481.00-11
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
A. RISK MANAGEMENT ACTIONS
Risk
Management
Action
Reportable
Quantity (RQ)
Status
Date
Final
1985
Risk
Management
Value
1000 IDS
Considers
Econ/Tech
Feasibility
no
Reference
50 FR 13456
04/04/85
Water Quality
Criteria (WQC):
a. Human Health Final
1980
b.AquaticToxicity
1) Freshwater Final
1980
2) Marine
Clean Air Act
Regulatory
Decision:
(NESHAPorNSPS)
Final
1980
Final
1984
14.3 mg/1
no
Acute no
17,500 ug/l (LEL)
Chronic
none
Acute no
6,300 ug/l (LEL)
Chronic
5,000 ug/l (LEL)
Decision not no
to Regulate
45 FR 79318
11/28/80
ibid.
ibid.
49 FR 22195
05/25/84
B. RISK MANAGEMENT RATIONALE
RQ
The final RQ is based on aquatic toxicity, as established under Section 311(b)(4)
of the Clean Water Act, ignitability and chronic toxicity. Available data indicate
that the aquatic 96-Hour Median Threshold Limit for Toluene is between 10 and 100
ppm. Its closed cap flash point is less than 100 degrees F and its boiling point is
greater than 100 degrees F. RQ assignments based on chronic toxicity reflect two
primary attributes of the hazardous substance, the minimum effective dose (MED)
levels for chronic exposure (mg/day for 70-kg man) and the type of effect (liver
necrosis, teratogenicity, etc). In accordance with the methodology described in the
Agency's "Technical Background Document to Support Rulemaking Pursuant to
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OSWER Directive 9481.00-11
CERCLA Section 102, Volume 1" of March 1985 and 50 FR 13468 (04/04/85), a
composite score is determined from an evaluation of these two attributes. Toluene
was determined to have a composite score between 6 and 20, corresponding to a
chronic toxicity RQ of 1000 pounds.
Contact: RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
WQC
Contact: Office of Water Regulations and Standards
202-382-5400 or fTS-382-5400
a. Human health: The WQC of 14.3 mg/l is based on consumption of
contaminated aquatic organisms and water. A WQC of 424 mg/l has also been
established based on consumption of contaminated aquatic organisms alone.
b. Aquatic toxicity: Water quality criteria for the protection of aquatic life are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The "(LED" after the vafue indicates that the minimum data were not
available and the concentration given is not a criteria value but the lowest effect
level found in the literature.
CAA Regulatory Decision
EPA concluded that current information does not indicate that toluene
endangers public health at ambient concentrations (excluding emergency releases),
and thus no regulation directed specifically at toluene is necessary at this time
under the CAA.
Contact: Chief, Pollutant Assessment Branch
FTS/629-5645 or 919/541-5645
V. SUPPLEMENTARY DATA
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
Synonyms: ANTISAMa, METHYL-BENZENE, METHACIDE, PHENYL-METHANE,
METHYLBENZENE, METHYLBENZOL, NCI-C07272, PHENYLMETHANE, RCRA WASTE
NUMBER U220, TOLUEEN (Dutch), TOLUEN (Czech),TOLUENE , TOLUOL, TOLUOLO
(Italian), TOLU-SOL, UN 1294
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OSWER Directive 9481.00-11
RESOURCE DOCUMENTS FOR TOLUENE
American Conference of Governmental Industrial Hygienists, Documentation of
the Threshold Limit Values. 4th ed.. Cincinnati. Ohio. 1980,488pp.
McCoy and Associates, "Physical/Chemical Data Compendium for Common
Solvents," The Hazardous Waste Consultant. Vol. 4, No. 6, Nov./Dec., 1986, pp.
4-1 to 4-32.
National Institute for Occupational Safety and Health. Criteria for a Recommended
Standard-Occupational Exposure to Toluene. DHEW Publication No. (NIOSH)
HSM73-11023. Washington, D.C., 1983.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base. Washington. D.C., October, 1983.
National Research Council, The Alkyl Benzenes. National Academy Press,
Washington, D.C., 1980.
Sax, N. I., Dangerous Properties of Industrial Materials, 4th ed.. Van Nostrand
Reinhold Co., New York, 1975,1,258 pp.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Toluene. EPA/440-5.-80-075, Office of Water Regulations and Standards,
Criteria and Standards Division, Washington, D.C., October, 1980.
U.S. Environmental Protection Agency, Health Effects Assessment for Toluene.
Final Draft. ECAO-CIN-HO-03, Environmental Criteria and Assessment Office,
Cincinnait, Ohio, September, 1984.
U.S. Environmental Protection Agency. Water-Related Environmental Fate of 129
Priority Pollutants. EPA/440-4-79-024, Washington, D.C., December 1979.
Weast, R. E., ed., Handbook of Chemistry and Physics. 62nd ed., CRC Press,
Cleveland, Ohio, 1981,2,332 pp.
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OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
1,1,1-TRICHLOROETHANE
CAS Number: 71-55-fr
Chemical Formula: CHaCGa
IUPAC Name: 1,1,1-Trichloroethane
Important Synonyms and Trade Names: Methyl chloroform, chlorothene, 1,1,1 -TCA
Chemical and Physical Properties
Molecular Weight:
Boiling Point:
Melting Point:
Specific Gravity:
Solubility in Water:
Solubility in Organics:
Vapor Pressure:
Vapor Density:
Viscosity:
Flash Point:
133.41
74.1°C
-30.4°C
1.34 at 20°C (liquid)
480-4,400 mg/liter at 20°C (several divergent values were
reported in the literature)
Soluble in acetone, benzene, carbon tetrachloride,
methanol, ether, alcohol, and chlorinated solvents
123mmHgat20°C
4.63
0.889 centipoise at 16°C
Not flammable
Log Octanol/Water Partition Coefficient: 2.17
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
1,1,1-Trichloroethane; CAS No. 71-55-6 (Revised 09/30/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
"•
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic toxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR 1,1,1 -Trichloroethane
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: under review
III. Drinking Water Health Advisories: none
IV. Regulatory Actions: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may
exist for certain toxic effects such as cellular necrosis, but may not exist for other
toxic effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
.noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6 . Preparation Date: 03/18/87
1. REFERENCE DOSE SUMMARY TABLE
i
Critical Effect Experimental Doses * UF MF RfD
No adverse effects NOAEL: 500ppm(air) 1000 1 9E-2
(2730mg/cu.m) mg/kg/day
Guinea Pig 6-Month converted to
Inhalation Study 90/mg/kg/day
Torkelson etal.,
1958
Slight growth LOAEL: 650 ppm (air)
retardation (3550 mg/cu.m)
(converted to
Guinea Pig 120 mg/kg/day)
2-3 Month
Inhalation Study
Adams etal., 1950
* Dose Conversion Factors & Assumptions: dose (mg/cu.m) x 7 hours/24 hours x 5
daysx(0.3)x(0.23cu.m/day/0.43 kg) where: 0.3 is the assumed inhalation
retention factor, and 0.23 cu.m/day /0.43 kg are the assumed ventilation rate
and body weight of the guinea pig, respectively.
2. PRINCIPAL AND SUPPORTING STUDIES
Torkelson, T.R., F. Oven, D.D. McCollister and V.K. Rowe. 1958. Toxicity of 1,1,1-
trichloroethane as determined on laboratory animals and human subjects. Am. Ind.
Hyg.Assoc.J. 19:353-362.
Adams, E.M., H.C. Spencer, V.K. Rowe and D.D. Irish. 1950. Vapor toxicity of 1,1,1-
trichloroethane (methyl chloroform) determined by experiments on laboratory
animals. Arch. Ind. Hyg. Occup. Med. 1: 225-236.
Torkelson et al. (1958) exposed groups of rats, rabbits, guinea pigs and
monkeys to 1,1,1 -trichloroethane vapor at concentrations or 500, 1000, 2000 or
10,000 ppm. From these studies, it was determined that the female guinea pig was
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OSWER Directive 9481.00-11
the most sensitive species of those tested. At 500 ppm, groups of eight male and
eight female guinea pigs showed no evidence of adverse effects compared with
unexposed and air-exposed controls after exposure for 7 hours/day, 5 days/week for
6 months. Groups of five female guinea pigs exposed to 1000 ppm 1,1,1-
trichloroethane vapor 3 hours/day, 5 days/week for 3 months had fatty changes in
the liver and statistically significant increased liver weights. Thus, this study defined
a NOAEL of 500 ppm (2730 mg/cu.m) in guinea pigs.
Adams etal. (1950) subjected groups of 6-10 male and female guinea pigs to
650 ppm 1,1,1 -trichloroethane vapor 7 hours/day, 5 days week for 2-3 months.
These animals exhibited a slight depression in weight gain compared with both air-
exposed and unexposed controls, thereby establishing a LOAEL of 650 ppm (3550
mg/cu.m) in guinea pigs.
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 1000. Factors of 10 each were employed for use of a subchronic assay, for
extrapolation from animal data, and for protection of sensitive human sub-
populations.
MF = 1
4. ADDITIONAL COMMENTS
The 1,1,1-trichloroethane samples used byTorkelson etal. (1958) were found
to be 94-97% pure while the samples used in the Adams et al. (1950) study had a
purity of greater than or equal to 99%.
The effects of 1,1,1-trichloroethane vapor have been investigated in mice
(Quast et al., 1984; McNutt et al., 1975), rats (Quast et al.f 1978), and rabbits and
dogs (Pendergast et al., 1967). The only chronic oral exposure study was conducted
by NCI (1977) in rats. The observations from these studies and from Torkelson et al.
(1958) and Adams et al. (1950) are somewhat inconsistent, thus making conclusions
difficult regarding which dose levels of 1,1,1-trichloroethane result in adverse
effects. For example, exposure to 650 ppm in the Adams et al. (1950) inhalation
study was associated with slight growth retardation in guinea pigs. Further review
of this study indicates that 1500 ppm exposure also caused slight growth
retardation without causing any organ specific adverse effects following 1-3 months
exposure. These observations are in contrast with those of Torkelson et al. (1958)
who observed adverse effects in the liver and lungs of guinea pigs exposed to 1000
ppm for 90 days. Results and technical evaluation of recent inhalation studies in
mice (Quast etal., 1984) and rats conducted by Dow Chemical will be of greater
value for the overall RfD consideration for 1,1,1-trichloroethane.
5. CONFIDENCE IN THE RfD
Study: Low DataBase: Medium RfD: Medium
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OSWER Directive 9481.00-11
Although both the Adams et al. (1950) and Torkelson et al. (1958) studies used
both sexes of several species, the number of animals at each dose level was limited,
the length of exposure varied with different dose levels, and few toxic endpoints
were examined. Confidence in these studies is thus considered low. The data base is
fairly comprehensive; however, results from these studies are somewhat
inconsistent and some of the more recent studies have yet to be critically evaluated.
Confidence in the data base is, therefore, rated medium while the RfD is rated
medium to low.
6. DOCUMENTATION AND REVIEW
The only U.S. EPA documentation at present is on IRIS.
Agency RfD Work Group Review: 05/31/85, 07/08/85,07/22/85,05/15/86
Verification Date: 05/15/86
7. U.S. EPA CONTACTS
Primary: M.L.Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
Secondary: Y. Patel FTS/382-7585 or 202/382-7585
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6
This chemical is among those substances evaluated by the U.S. EPA for
evidence of human carcinogenic potential. This does not imply that this chemical is
necessarily a carcinogen. The evaluation for this chemical is under review by an
inter-office Agency work group. A risk assessment summary will be included on IRIS
when the review has been completed.
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OSWER Directive 9481.00-11
III. DRINKING WATER HEALTH ADVISORIES
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6
Information is not available at this time.
IV. REGULATORY ACTIONS
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6 Preparation Date: 09/30/87
INTERPRETATION OF REGULATORY ACTION INFORMATION
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Regulatory actions are frequently not
updated at the same time. Carefully read the dates for the regulatory actions (in
this section) and the verification dates for the risk assessments (in sections I & II), as
this may explain apparent inconsistencies. Also note that some regulatory actions
consider factors not related to health risk, such as technical or economic feasibility.
Such considerations are indicated for each action following (Econ/Tech Feasibility
entry). In addition, not all of the regulatory actions listed in this section involve
enforceable federal standards. Please direct any questions you may have
concerning the use of risk assessment information in making a regulatory decision
to the U.S. EPA contact listed for that particular regulatory action. Users are
strongly urged to read the background information on each regulatory action in
Appendix D in Service Code 4.
A. AIR
Information is not available at this time.
B. WATER
MAXIMUM CONTAMINANT LEVEL GOAL (MCLG); for Drinking Water
Value (status) - 200 ug/L (Final, 1987)
Considers technological or economic feasibility? -- NO
Discussion -- An MCLG of 200 ug/L for 1,1,1-trichloroethane is proposed based upon
a DWELand an assumed drinking water contribution of 20%. A DWELof 1.0 mg/L
was calculated based on liver toxicity in mice (inhalation study).
Reference -- 52 FR 25690 (07/08/87)
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OSWER Directive 9481.00-11
US EPA Contact-- Office of Drinking Water
202/382-5543 or FTS/382-5543
C. TOXICS /PESTICIDES
Information is not available at this time.
D. SUPERFUND
Information is not available at this time.
V. SUPPLEMENTARY DATA
Chemical: 1e1,1=Trichloroethane
CAS No.: 71-55-6
Information is not available at this time.
SYNONYMS: ETHANE, 1,1,1-TRICHLORO-; AEROTHENE TT; CHLOROETENE;
CHLOROETHENE; CHLOROETHENE NU; CHLOROFORM, METHYL-; CHLOROTHANE
NU; CHLOROTHENE; CHLOROTHENE(lnhibited); CHLOROTHENE NU;
CHLOROTHENE VG; CHLORTEN; INHIBISOL; METHYLCHLOROFORM; METHYL
CHLOROFORM (ACGIH.DOT); METHYLTRICHLOROMETHANE; NCI-C04626; RCRA
WASTE NUMBER U226; SOLVENT 111; STROBANE; alpha=T; 1,1.1-TCE; 1,1.1-
TRICHLOORETHAAN (Dutch); 1,1,1-TRICHLORAETHAN (German); TRICHLORO-1,1,1-
ETHANE (French); alpha-TRICHLOROETHANE; 1,1,1-TRICHLOROETHANE; 1,1,1-
TRICHLOROETHANE (DOT); 1,1,1-TRICLOROETANO (Italian); TRI-ETHANE; UN 2831
(DOT)
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OSWER Directive 9481.00-11
RESOURCE DOCUMENTS FOR 1,1,1-TRICHLOROETHANE
International Agency for Research on Cancer, "IARC Monographs on the Evaluation
of the Carcinogenic Risks of Chemicals to Humans", Vol. 20: Some
Haloqenated Hydrocarbons. World Health Organization, Lyon, France, 1979,
pp. 515-531.
National Cancer Institute* Bioassav of 1.1.1-Trich!oroethane for Possible
Carcinoqenicitv. NCI CarcinogenesisTechnical Report Series No. 3, DHEW
Publication No. (NIH) 77-803, Washington, D.C., 1977.
National Institute for Occupational Safety and Health, Criteria for a Recommended
Standard-Occupational Exposure to 1.1.1-Trichloroethane (Methyl
Chloroform). DHEW Publication (NIOSH) 76-184, Washington, D.C., 1976.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base. Washington. D.C. October 1983.
National Toxicology Program, Annual Plan for Fiscal Year 1984. NTP-84-023,
DHHS Public Health Service, Research Triangle Park, N.C., 1984.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Chlorinated Ethanes. EPA/440-5-80-029, Washington, D.C., October, 1980.
U.S. Environmental Protection Agency, Health Effects Assessment for 1.1.1 -
Trichloroethane. Final Draft. ECAO-CIN-HO-05, Environmental Criteria and
Assessment Office, Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Water Related Environmental Fate of 129
Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December, 1979.
Vershueren, K.f Handbook of Environmental Data on Organic Chemicals, Van
Norstrand Reinhold Co., New York, 1977, 659 pp.
Weast, R.E., ed., Handbook of Chemistry and Physics, 62nd ed., CRC Press, Cleveland,
Ohio, 1981,2332pp.
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CHEMICAL AND PHYSICAL PROPERTIES OF
TRICHLOROETHYLENE
CAS Number: 79-01-6
Chemical Formula: C2HC13
IDPACName: Trichloroethene
Important Synonyms and Trade Names: Trichloroethene, TCE, and ethylene
trichloride
Chemical and Physical Properties
Molecular Weight: 131.5
Boiling Point: 87°C
Melting Point: -73°C
Specific Gravity: 1.4642 at 20°C
Solubility in Water: 1,000 mg/!iter
Solubility in Organics: Soluble in alcohol, ether, acetone, and chloroform
Henry's Law Constant: 8.92 x 10-3 atm-m3/mole at 25°C
Vapor Pressure: 60 mm Hg at 20°C
Vapor Density: 4.53
Viscosity: 0.610 centipoise at 15.6°C
Flash Point: 32°C (closed cup)
Log Octanol/Water Partition Coefficient: 2.29
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INTEGRATED RISK INFORMATION SYSTEM (IRIS):Chemical Files
Trichloroethylene; CAS No. 79-01-6 (Revised 03/31/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronictoxicity data by work groups composed or U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most,
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Trichloroethylene
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: under review
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Trichloroethylene
CAS No.: 79-01-6
A risk assessment for this chemical is under review by an EPA work group.
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B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available.at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Trichloroethylene
CAS No.: 79-01-6 Preparation Date: 02/18/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification: B2, probable human carcinogen; based on positive responses in ,
two strains of mice by two routes and suggestive increases in tumor
incidences in male rats by gavage. Supporting evidence does not
downgrade the classification.
1. HUM AN DATA
Three cohort studies of exposed workers (Axelson, 1978; Tola et al., 1980;
Malek et al., 1979) found no excess cancer risk associated with trichloroethylene
exposure. Results from a case-control study of malignant lymphoma cases by
Hardell (1981) were suggestive of an association between trichloroethylene
exposure and malignant lymphoma, but the study had various limitations. Studies
by Novotnaetal. (1979) and Paddle (1983) of liver cancer cases found no association
with trichloroethylene exposure. No controls were used in the latter two studies.
2. ANIMAL DATA
Positive evidence of carcinogenicity has generally come from studies of mice.
Negative results have been obtained from gavage treatment of Osborne-Mendel
rats, Sprague-Dawley rats and ICR/Ha Swiss mice (NCI, 1976; Maltoni, 1979;
Henschler et al., 1984). The NCI (1976) study may be inconclusive due to high
mortality and the Maltoni (1979) exposure was carried out for a less-than-lifetime
period. An NTP (1983) study found a small increase in incidence of renal
adenpcarcinomas in male Fischer 344 rats treated by gavage. This was significant by
statistical tests that took survival differences into account, but not by the
unadjusted Fisher Exact test.
Henschler et al. (1980) found a significant increase in malignant lymphomas in
female Han:NMRI mice exposed by inhalation. The spontaneous incidence of
lymphomas in controls was also high. Inhalation treatment of the following
produced negative results: Charles River rats; Han:Wist rats, Syrian hamsters and
male Han:NMRI mice (Bell et al., 1978; Henschler et al., 1980).
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Trichloroethylene did not serve as either an initiator or as a complete skin
carcinogen (van Duuren et al., 1979). Trichloroethylene oxide was also negative in
an initiation-promotion assay and after s.c. injection.
Male and female B6C3F1 mice were treated 5 days/week for 78 weeks by corn
oil gavage with epoxide-stabilized trichloroethylene. Doses were TWA were 1169
and 2339 mg/kg for males and 869 and 1739mg/kg for females cinomas (NCI, 1976).
A repeat bioassay confirmed the observation of increased incidence of
hepatocellular carcinoma. In this study, male and female B6C3F1 mice were treated
with purified trichloroethylene containing no detectable epoxides by corn oil
gavage of 1000 mg/kg/day, 5 days/week for 103 weeks (NTP, 1983).
3. SUPPORTING DATA
Trichloroethylene of various grades of purity was negative or weakly positive
in mutagenicity assays with S. typhimurium, E. coli and S. pombe. It was mutagenic
for both S. cerevisiae and in the mouse spot test. While tests for chrompsomar
aberrations were negative, trichloroethylene produced mitotic recombination in S.
cerevisiae and borderline positive responses in assays of SCE (after occupational
exposure) and unscheduled DMA synthesis. Metabolites of trichloroethylene have
likewise produced variable, largely negative, responses (U.S. EPA, 1985).
Trichloroethylene oxide, however, has been shown to transform Syrian hamster
embryo cells after in vitro exposure (DiPaolo and Doniger, 1982).
B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 1.1 E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 C/ug/L)
3E + 2 ug/L 3E +1 ug/L 3 ug/L 3.2E-7 LM, extra
risk
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2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Slope Reference
Tumor Type Administered Human Equivalent Incidence Factor
Mouse/B6C3F1, Route: Oral, gayage
male and
female;
hepatocellular
carcinomas mg/kg/day mg/kg/day /mg/kg
/day
male 0 0 8/48 1.9E-2 NTP, 1983
1000 47.39 30/50
female 0 0 2/49 8.0E-3
1000 45.62 13/49
male 0 0 1/20 1.8E-2 NCI, 1976"
1169
2339
female 0
869
1739
45.11
85.80
0
31.65
61.43
26/50
31/48
0/20
4/50
11/47
5.8E-3
3. ADDITIONAL COMMENTS
Metastases to the lungs were observed in one control male and five treated
males in the NTP (1983) study. Survival of treated males was decreased by
comparison with controls. Doses for the NCI (1976) study are TWA. There was little
toxicity in this study not attributed to tumor development. The slope factor used
for the unit risk is tne geometric mean of the four slope factors above.
Data on metabolism of gavaged trichloroethylene in Swiss Cox mice (Buben
and O'Flaherty, 1985) suggest that the NTP (1983) gavage assay dose of 1000
mg/kg/day is within the linear portion of the dose/amount metabolized curve; the
high doses of the NCI (1976) bioassay approach the saturation of metabolism.
Human equivalent lifetime average metabolized doses were calculated as follows:
human equivalent dose = weeks treated/weeks observed x 5 days/7 days x
animal metabolized dose in (mg/day) x (WH/WA)
**2/3
where: WH = 70kg
WA = 0.04 kg male mice, 0.035 female mice (NTP, 1983); 0.033
kg male, 0.026 female (NCI, 1976)
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The unit risk should not be used if the water concentration exceeds 3E + 4
ug/L, since above this concentration the slope factor may differ from that
stated.
4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE RISK ESTIMATE
Slope factors for male and female B6C3F1 mice from two independent studies
are very close (all within a factor of 3). Adequate numbers of animals were studied,
and tumor incidences were significantly elevated comparably, although the follow-
up studies had only only one positive dose group. Confidence in the risk estimate is
rated medium to high.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
C. INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 1.3E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
8E + 1ug/cu.m 8 ug/cu.m 8E-1 ug/cu.m 1.3E-6 LM, extra
risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Calculated from oral data as follows:
Unit risk = 1.3E-2 X9.9E-5
where: 1.3E-2 = slope factor (/mg metabolized dose/kg/day)
9.9E-5 = body metabolite load
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3. ADDITIONAL COMMENTS
Data by Monster etal. (1976) were used as the basis for estimation of the
amount of trichloroethylene metabolized by humans exposed to 1 mg/cu.m. The
mean amount metabolized was 439 mg for four subjects exposed to 70 ppm for 4
hours. The amount of metabolite formed following continuous 24-hour exposure
to 1 ug/cu.m was estimated to be 9.9E-S mg/kg/day.
The unit risk should not be used if the air concentration exceeds 8E + 3
ug/cu.m, since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
There are data from metabolism studies on inhalation of trichloroethylene by
human subjects to justify dose assumptions. Confidence in this inhalation risk
estimate derived from oral data is rated medium.
Note: Although the statement of confidence in the quantitative estimate is a -
consensus of the Agency Work Group, it is a somewhat subjective judgment. The,
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete. ;
D. DOCUMENTATION AND REVIEW
1. REFERENCES
U.S. EPA. 1985. Health Assessment Document for Trichloroethylene. Prepared by
the Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Research Triangle Park, NC. EPA 600/8-82-006F.
NTP (National Toxicology Program). 1983. Carcinogenesis Bioassay of
Trichloroethylene (CAS No. 79-01-6). NTP Report No. 81-84. Dept. HHS. Publ. No.
83-1799.
NCI (National Cancer Institute). 1976. Carcinogenicity Bioassay of Trichloroethylene
(CAS No. 79-02-6). Carcinogenesis Technical Report Series No. 2.
2. REVIEW
The 1985 Health Assessment Document for Trichloroethylene received both an
Agency and external review.
Agency Work Group Review: 12/04/86
Verification Date: 12/04/86
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3. U.S. EPA CONTACTS
Primary: R. Beliles 202/382-7436 or FTS/382-7436
Office of Research and Development
Secondary: C.Chen 202/382-5898 or FTS/382-5898
Office of Researched Development
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical: Trichloroethylene
CAS No.: 79-01-6 Preparation Date: 03/31/87
INTERPRETATION OF RISK MANAGEMENT DATA .
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
A. RISK MANAGEMENT ACTIONS
Risk Status Risk Considers
Management Management Econ/Tech
Action Date Value Feasibility Reference
Reportable Proposed 100 Ibs no > 52 FR 8140
Quantity (RQ) • 1987 03/16/87
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Clean Air Act (CAA)
Regulatory Decision:
Nat Emissions Current Under no 50 FR 52422
Standards for 1985 development 12/23/85
Hazardous Air
Pollutants (NESHAP)
B. RISK MANAGEMENT RATIONALE
RQ
The proposed RQ fortrichloroethylene is 100 pounds, based on potential
carcinogenicity. The available data indicate a hazard ranking of low, based on a
potency factor of 0.070 (mg/kg/day)-1 and weight-of-evidence classification B2,
which corresponds to an RQ of 100 pounds.
Contact: Office of Emergency and Remedial Response
202/382-2180 or FTS/382-2180
CAA Regulatory Decision
NESHAP: Trichloroethylene (TCE) is a probable human carcingen (EPA Group
B2) and according to EPA's preliminary risk assessment from ambient air exposures,
public health risks are significant (4.1 cancer cases per year and maximum lifetime
individual risks of 9.4x10-5). Thus, EPA indicated that it intends to add TCE to the
list of hazardous air pollutants for which it intends to establish emission standards
under section 112(b)(1)(A) of the Clean Air Act. The EPA will decide whether to add
TCE to the list only after studying possible techniques that might be used to control
emissions and further assessing the public health risks. The EPA will add TCE to the
list if emissions standards are warranted.
Contact: Chief, Pollutant Assessment Branch
FTS/629-5645 or 919/541-5645
V. SUPPLEMENTARY DATA
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available at this time.
SYNONYMS: ETHYLENE,TRICHLORO-; ACETYLENE TRICHLORIDE; ALGYLEN;
ANAMENTH; BENZINOL; BLACOSOLV; BLANCOSOLV; CECOLENE; CHLORILEN; 1-
CHLORO-2,2- DICHLOROETHYLENE; CHLORYLEA; CHLORYLEN; CHORYLEN;
GRCOSOLV; CRAWHASPOL; DENSiNFLUAT; 1,1-DICHLORO-2-CHLOROETHYLENE;
DOW-TRI; DUKERON; ETHINYLTRICHLORIDE; ETHYLENE TRICHLORIDE; FLECK-FLIP;
FLOCK FLIP; FLUATE; GEMALGENE; GERMALGENE; LANADIN; LETHURIN;
NARCOGEN; NARKOGEN; NARKOSOID; NCI-C04546; NIALK; PERM-A-CHLOR;
PERM-A-CLOR; PETZINOL; PHILEX; RCRA WASTE NUMBER U228; TCE;
THRETHYLEN; THRETHYLENE; TRETHYLENE; TRI; TRIAD; TRIAL; TRIASOL;
TRICHLOORETHEEN (Dutch); TRICHLOORETHYLEEN, TRI (Dutch); TRICHLORAETHEN
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(German); TRICHLORAETHYLEN,TRI (German); TRICHLORAN; TRICHLOREN;
TRICHLORETHENE (French); TRICHLORETHYLENE; TRICHLORETHYLENE, TRI
(French); TRICHLOROETHENE; TRICHLOROETHYLENE; 1,1,2-TRICHLOROETHYLENE
1,2,2-TRICHLOROETHYLENE; TRICHLOROETHYLENE (ACGIH,DOT); TRI-CLENE;
TRICLORETENE (Italian); TRICLOROETILENE (Italian); TRIELENE; TRJELIN; TRIELINA
(Italian); TRIKLONE; TRILEN; TRILENE; TRIUNE; TRIMAR; TRIOL; TRI-PLUS; TRI-PLUS
M; UN 1710 (DOT); VESTROL; VITRAN; WESTROSOL
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RESOURCE DOCUMENTS FOR TRICHLOROETHYLENE
International Agency for Research on Cancer, "Some Halogenated Hydrocarbons,"
IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to
Humans, Vol. 20, World Health Organization, Lyon, France, pp. 545-572.
McCoy and Associates, "Physical/Chemical Data Compendium for Common
Solvents," The Hazardous Waste Consultant Vol. 4, No. 6, Nov./Dec., 1986, pp
4-1 to 4-32
National Cancer Institute, Bioassay of Trichloroethylene for Possible
Carcinoqenicitv. CAS No. 79-01-6, NCI Carcinogenesis Technical Report Series
No. 2, DHEW Publication No. (NIH) 76-802, Washington, D.C, 1976.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base. Washington, D.C., October 1983.
National Toxicology Program, Carcinoqenesis Bioassav of Trichloroethylene.
CAS No. 79-01-6, NTP81-84, NIH Publication No. 82-1799,1982.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Trichloroethylene. EPA/400-5-80-077, Office of Water Regulations and
Standards, Criteria and Standards Division, Washington, D.C., October 1980
U.S. Environmental Protection Agency, Health Assessment Document for
Chloroform. EPA/600-8-84-004F, Office of Health and Environmental
Assessment, Washington, D.C., September 1984.
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants. EPA 440/4-79-029, Washington, D.C, December 1979.
Verschueren, K.. Handbook of Environmental Data on Organic Chemicals.
Van Nostrand Reinhold Co., New York, 1977, 659 pp.
Waters, E.M., Gerstner, H.B., and Huff, J.E., "Trichloroethylene: 1. An Overview,"
J.Toxicol. Enivron Health. 2:674-700.
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OSWER Directive 9481 00-11
Weast, R.E., ed., Handbook of Chemistry and Physics, 62nd ed., CRC Press,
Cleveland, Ohio, 1981,2,332 pp.
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OSW E R Di recti ve 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
XYLENES
Summary
Xyiene has three isomers, o-, m-, and p-xylene. These three generally have
similar chemical and biological characteristics and therefore will be discussed
together.
CAS Number: Mixed: 1330-20-7
m-Xylene: 108-38-3
o-Xylene: 95-47-6
p-Xylene: 106-42-3
Chemical Formula: CgH^CHa^
IDPACName: Dimethylbenzene
Important Synonyms and Trade Names:
Mixed xylene: Dimethylbenzene, xylol
m-Xylene: 1,3-Dimethylbenzene, m-xylol
o-Xylene: 1,2-Dimethylbenzene, o- xylol
p-Xylene: 1,4-Dimethylbenzene, p-xylol
Chemical and Physical Properties
Molecular Weight: 106.17
Boiling Point: Mixed: 137-140X
m-Xylene: 139°C
o-Xylene: 144°C
p-Xylene: 138°C
Melting Point: m-Xylene: -48°C
o-Xylene: -25°C
p-Xylene: 13°C
Specific Gravity: 0.86
Solubility in Water: 160 mg/liter at 25°C
Solubility in Organics: Soluble in alcohol, ether, and other organic sovlents
Vapor Pressure: 10mmHgat25°C
Vapor Density: 3.7
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Flash Point: 25°C (closed cup)
Log Octanol/Water Partition Coefficient: 3
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INTEGRATED RISK INFORMATION SYSTEM (IRIS):Chemical Files
Xylenes; CAS No. 1330-20-7 (Revised 09/30/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chroni.ctoxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Xylenes
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: none
III. Drinking Water Health Advisories: none
IV. Regulatory Actions: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Xylene (mixed isomers)
CAS No.: 1330-20-7 ,' Preparation Date: 09/30/87
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Hyperactivity, NOAEL: 250 mg/kg/day 100 1 2E + 0
decreased body (converted to 179 mg/kg/day
weight and mg/kg/day)
increased mortality
(males)
FEL: 500 mg/kg/day
Chronic Rat Gavage (converted to 357
Study mg/kg/day)
NTP, 1986
* Dose Conversion Factors & Assumptions: Dose adjusted for gavage schedule (5
days/week).
2. PRINCIPAL AND SUPPORTING STUDIES
NTP (National Toxicology Program). 1986. NTP Technical Report on the Toxicology
and Carcinogenesis of Xylenes (mixed) (60.2% m-xylene, 13,6% p-xylene, 17.0%
ethylbenzene and 9.1% 0-xylene) (CAS No. 1330-20-7) in F344/N rats and B6C3F1
mice (gavage studies). U.S. DHHS, PHS, NIH, NTP, Research Triangle Park, NC. NTP
TR 327, NIH Publ. No. 86-2583.
Groups of 50 male and 50 female Fischer 344 rats and 50 male and 50 female
B6C3F1 mice were given gavage doses of 0,250, 500 mg/kg/day (rats) and 0, 500,
1000 mg/kg/day (mice) for 5 days/week for 103 weeks. The animals were observed
for clinical signs of toxicity, body weight gain and mortality. All animals that died or
were killed at sacrifice were given gross necropsy and comprehensive histological
examinations. There was a dose-related increased mortality in male rats, and the
increase was significantly greater in the high-dose group compared with controls.
Although increased mortality was observed at 250 mg/kg/day, the increase was not
significant. Although many of the early deaths were caused by gavage error, NTP
(1986) did not rule out the possibility that the rats were resisting gavage dosing
because of the behavioral effects of xylene. Mice given the high dose exhibited
hyperactivity, a manifestation of CNS toxicity. There were no compound-related
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histopathological lesions in any of the treated rats or mice. Therefore, the high
dose is a PEL and the low dose a NOAEL
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 100. An uncertainty factor of 100 was chosen: 10 for species-to-
species extrapolation ana 10 to protect sensitive individuals.
IN/IF = 1
4. ADDITIONAL COMMENTS
U.S. EPA (1984) reported an R^D of 0.01 mg/kg/day. based on a rat dietary
NOAEL of 200 ppm or 10 rng/kg/day as defined by Bowers etaL (1982) in a
6-month study. This NOAEL was divided by an uncertainty factor of 1000. U.S.
EPA (1985,1986a) noted that this study used aged rats, l©ssof xyiene from
volatilization was not controlled, only one exposure level was used, and
histopathological examination was incomplete. An RfDof 4.31 mg/day (about
0.06 mg/kg/day) based on an inhalation study (Jenkins et al., 1970) using
rats, guinea pigs, monkeys and dogs exposed to o-xylene at 3358 mg/cu.m, 8
hours/day, 5 days/week for 6 weeks or at 337 mg/cu.m continuously for 90 days
was derived by U.S. EPA (1985). Deaths in rats and monkeys, and tremors in
dogs occurred at the highest dose; whereas, no effects were observed in the
337 mg/cu.m continuous exposure group. The RfD based on the NTP (1986) study
is preferrable because it is based on a chronic exposure in two species by a
relevant route of administration, and comprehensive histology was performed.
Xyiene is fetotoxic and teratogenic in mice at high oral doses (Nourot and
Staples, 1981; Marks etaL, 1982), but the RfD as calculated should be
protective of these effects.
5. CONFIDENCE IN THE RfD
Study: Medium DataBase: Medium RfD: Medium
The NTP (1986) study was given a medium confidence level because it was a
well designed study in which adequately sized groups of two species were tested
over a substantial portion of their lifespan, comprehensive histology was performed
and a NOAEL was defined; but clinical chemistries, blood enzymes and urinalysis
were not performed. The data base was given a medium confidence level because,
although supporting data exist for mice and teratogenicity and fetotoxicity data are
available with positive results at high oral doses, a LOAEL for chronic oral exposure
has not been defined. Medium confidence in the RfD follows.
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6. DOCUMENTATION AND REVIEW
U.S. EPA. 1986a. Health and Environmental Effects Profile for Xylenes (o-, m-, p-).
Prepared by the Office of Health and Environmental Assessment, Environmental
Criteriaand Assessment Office, Cincinnati, OH and the Environmental Criteria and
Assessment Office, Research Triangle Park, NC for the Office of Solid Waste and
Emergency Response and the Off ice of Air Quality Planning and Standards, Off ice of
Air and Radiation, Washington, DC.
Limited peer review and extensive agency-wide review, 1986.
U.S. EPA. 1985. Drinking Water Criteria Document For Xylenes. Prepared by Office
of Health and Environmental Assessment, Environmental Criteria and Assessment
Office, Cincinnati, OH for the Office of Drinking Water, Washington, DC.
Extensive peer review agency-wide review.
U.S. EPA. 1984. Health Effects Assessment for Xylene. Prepared by the Office of
Health and Environmental Assessment, Environmental Criteria and Assessment
Office, Cincinnati, OH for the Office of Emergency and Remedial Response,
Washington, DC.
ECAO internal review and limited agency review.
Agency RfD Work Group Review: 12/05/85,03/19/87
Verification Date: 03/19/87
7. U.S. EPA CONTACTS
Primary: H. Choudhury FTS/684-7536 or 513/569-7536
Office of Research and Development
Secondary: CT. DeRosa FTS/684-7534 or 513/569-7534
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Xylenes
CAS No.: 1330-20-7
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical Xylenes
CAS No.: 1330-20-7
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This chemical has not been evaluated by the U.S. EPA for evidence of
human carcinogenic potential.
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Xylenes
CAS No.: 1330-20-7
Information is not available at this time.
IV. REGULATORY ACTIONS
Chemical: Xylene
CAS No.: 1330-20-7 Preparation Date: 09/30/87
INTERPRETATION OF REGULATORY ACTION INFORMATION
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Regulatory actions are frequently not
updated at the same time. Carefully read the dates for the regulatory actions (in
this section) and the verification dates for the risk assessments (in sections I & II), as
this may explain apparent inconsistencies. Also note that some regulatory actions
consider factors not related to health risk, such as technical or economic feasibility.
Such considerations are indicated for each action following (Econ/Tech Feasibility
entry). In addition, not all of the regulatory actions listed in this section involve
enforceable federal standards. Please direct any questions you may have
concerning the use of risk assessment information in making a regulatory decision
to the U.S. EPA contact listed for that particular regulatory action. Users are
strongly urged to read the background information on each regulatory action in
Appendix D in Service Code 4.
A. AIR
Information is not available at this time.
B. WATER
MAXIMUM CONTAMINANT LEVEL GOAL (MCLG); for Drinking Water
Value (status) -- 0.44 mg/L (Proposed, 1985)
Considers technological or economic feasibility? -- NO
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Discussion - An MCLG of 0.44 mg/L for xylene is proposed based upon a DWEL of
2.2 mg/L and an assumed drinking water contribution of 20%. A DWEL (provisional)
of 2.2 mg/L was calculated fro ma NOAELof 337 mg/m3 (only dose tested) for body
weight, nematology and histopathologic effects in rats, guinea pigs, monkeys and
dogs in a 90-day inhalation study (Jenkins, 1970). An uncertainty factor of 1000 was
applied and human water consumption of 2 L/day was assumed.
Reference -- 50 FR 46936 Part IV (VI/13/85)
U.S. EPA Contact -- Office of Drinking Water
202/382-5543 or FTS/382-5543
C. TOXICS/PESTICIDES
Information is not available at this time.
D. SUPERFUND
Information is not available at this time.
V. SUPPLEMENTARY DATA
Chemical: Xylenes
CAS No.: 1330-20-7
Information is not available at this time.
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RESOURCE DOCUMENTS FOR XYLENES
NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH, Registry of Toxic
Effects of Chemical Substances. Data Base. Washington, D.C., October. 1983.
NATIONAL RESEARCH COUNCIL, The Alkyl Benzenes, National Academy Press,
Washington, D.C., 1980. •
U.S. ENVIRONMENTAL PROTECTION AGENCY, Initial Report of the TSCA Interaqencv
Testing Committee to the Administrator; Environmental Protection Agency.
EPA/560-10-78-001, January, 1978.
U.S. ENVIRONMENTAL PROTECTION AGENCY, Water-Related Environmental Fate of
129 Priority Pollutants. EPA/440-4-79-029, Washington, D.C, December, 1979.
U.S. ENVIRONMENTAL PROTECTION AGENCY, Health Effects Assessment for Xylene.
Final Draft, Environmental Criteria and Assessment Office, ECAO-CIN-H006,
Cincinnati, Ohio, September, 1984.
VERSCHUEREN, K.. Handbook of Environmental Data on Organic Chemicals. Van
Nostrand Reinhold Co., New York, 1977,659 pages.
WEAST, R.E.. ed.. Handbook of Chemistry and Physics. 62nd ed.. CRC Press,
Cleveland, Ohio, 1981,2,332 pages.
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ACL
CASE STUDY 2
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OSWER Directive 9481 00-11
CONTENTS
SECTION PAGE
1.0 EXECUTIVE SUMMARY. 1-1
2.0 INTRODUCTION • 2-1
2.1 FACILITY DESCRIPTION 2-1
2.2 APPROACH TO ACL DETERMINATION 2-4
2.3 REPORT ORGANIZATION 2-5
3.0 IDENTIFICATION OF ACL CONSTITUENTS 3-1
3.1 HAZARDOUS CONSTITUENTS IN THE WASTE 3-1
3.2 EXTENT AND DEGREE OF CONTAMINATION 3-1
4.0 GENERAL INFORMATION 4-1
4.1 LAND USE 4-1
4.2 WATER USE AND USERS 4-1
4.3 PRECIPITATION 4-3
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION 5-1
5.1 REGIONAL GEOLOGY 5-1
5.2 SITE GEOLOGY 5-3
5.3 GROUND-WATER HYDROLOGY 5-3
5.4 SURFACE WATER HYDROLOGY 5-8
6.0 EXPOSURE PATHWAYS 6-1
6.1 POTENTIAL HUMAN EXPOSURE 6-1
6.2 POTENTIAL ENVIRONMENTAL EXPOSURE 6-2
6.3 MAXIMUM ALLOWABLE EXPOSURE CONCENTRATIONS 6-3
7.0 DEVELOPMENTOFACLs 7-1
8.0 MONITORING PROGRAM 8-1
8.1 GROUND-WATER MONITORING 8-1
8.2 OTHER MONITORING 8-3
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CONTENTS (continued)
REFERENCES
R-1
APPENDICES
B
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
CHEMICAL AND PHYSICAL PROPERTIES FOR
BENZENE, CHROMIUM, METHYLENE
CHLORIDE, 1,1,1-TRICHLOROETHANE, AND
TRICHLOROETHYLENE; AND IRIS (INTEGRATED
RISK INFORMATION SYSTEM) DATA BASE FOR
CHROMIUM, METHYLENE CHLORIDE, 1,1,1-
TRICHLOROETHANE, AND TRICHLOROETHYLENE
A-1
B-1
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TABLES
NUMBER PAGE
3-1 Appendix VII Constituents Present at Facility K 3-2
3-2 Maximum Observed Concentrations (mg/L) at Sampling 3-4
Locations
3-3 Dimensions of Plumes 3-11
4-1 Inventory of Wells Within 3.1 Miles (5 Km) of the Facility 4-2
4-2 Average Monthly Precipitation 4-3
5-1 Hydraulic Conductivity Tests 5-9
6-1 Maximum Contaminant Levels 6-3
6-2 Allowable Exposure Levels for Ingestion of Water and Aquatic 6-6
Organisms
6-3 Allowable Freshwater Exposure Levels 6-7
6-4 Maximum Allowable Exposure Concentrations 6-8
7-1 Development of Attenuation Factor 7-2
7-2 Proposed Alternate Concentration Limits 7-4
8-1 POC Monitoring Wells 8-1
8-2 POE Monitoring Wells 8-2
-------
OSWER Directive 9481.00-11
FIGURES
NUMBER PAGE
2-1 Site Layout 2-2
3-1 Monitoring Well Locations and POEs 3-3
3-2 Isoplethsfor Benzene (mg/l) Based on Maximum 3-6
Concentrations (1984-1985)
3-3 Isoplethsfor Chromium (mg/l) Based on Maximum 3-7
Concentrations (1984-1985)
3-4 Isopleths for Methylene Chloride (mg/l) Based on Maximum 3-8
Concentrations (1984-1985)
3-5 Isoplethsfor 1S 1,1 -Trichloroethane (mg/l) Based on Maximum 3-9
Concentrations (1984-1985)
3-6 Isopleths for Trichloroethylene (mg/l) Based on Maximum 3-10
Concentrations (1984-1985)
5-1 Site Topography 5-2
5-2 Location of Cross Sections 5-4
5-3 Cross Sections A-A'and B-B' 5-5
5-4 Saturated Thickness of the Alluvial Aquifer (feet) 5-6
5-5 Flow Net for the Alluvial Aquifer 5-7
VI
-------
OSWER Directive 9481 00- n
1.0 EXECUTIVE SUMMARY
Case Study 2 is a hypothetical example of an application for alternate
concentration limits (ACLs) for five hazardous constituents (benzene, chromium,
methylene chloride, 1,1,1-trichloroethane, and trichloroethylene) in ground water
within the Facility K boundary. The contaminated ground water has not reached
surface waters and wetlands adjacent to the facility.
The facility is adjacent to a large river in the southeastern United States. There
are wetlands adjacent to the river. Land use in the area surrounding the facility
includes industrial, residential, and agricultural uses. There is a town of 8,500
persons 2 miles west of the facility and a small residential community to the
southwest.
Principal sources of water in the region are two aquifers separated by an
aquitard at least 30 feet thick. Facility K and neighboring industries use water from
the uppermost aquifer for industrial and/or domestic purposes. Surface water in
the vicinity of Facility K is used for industrial purposes, recreation, and recreational
fishing only.
Potential exposure pathways for humans include: (a) ingestion of
contaminated drinking water from the river or wells in the uppermost aquifer; and
(b) ingestion of contaminated aquatic species from the river. The potential
exposure pathway for ecosystems is by ground-water discharge to surface waters in
the wetlands and the river.
Maximum allowable concentrations at the point of exposure (POE) for: 1)
drinking water, 2) combined drinking water and fish ingestion, 3) acute ecosystem
exposure, and 4) chronic ecosystem exposure are compared for the five constituents.
The proposed ACL for each constituent is based on the lowest of these
concentrations multiplied by a factor that accounts for attenuation between the
Point of Compliance (POC) and the POE.
1-1
-------
OSWERDi reai ve 9481 00-11
2.0 INTRODUCTION
This is a hypothetical example of an application by Facility K for Alternate
Concentration Limits (ACLs) under 40 CFR 264.94 (b) for five hazardous constituents
(benzene, chromium, methylene chloride, toluene, 1,1,1-trichloroethane, and
trichloroethylene) that have been detected in the ground water beneath the
facility. Part I of the ACL Guidance Document (EPA, 1987a) discusses five cases
(scenarios) that illustrate the policies and terms presented in the document. The
demonstration presented in this application meets the conditions for Case 2
because Facility K is located above useable ground water that already has
contamination confined to the facility property. The Point of Exposure (POE) will be
assumed to be no farther from the Point of Compliance (POC) than the outer edge
of the existing plume.
Interim corrective actions, instituted under EPA's Corrective Action Order,
included closing Landfill A in April 1985, opening Landfill 8 (meeting minimum
technology requirements), and retrofitting the wastewater treatment lagoons to
meet minimum technology requirements. In addition, process changes were
undertaken to reduce the concentration of hazardous constituents in the
wastewater effluent and sludges in the treatment lagoons. It is understood that
EPA will evaluate the need for additional corrective action, especially as it pertains
to ground-water cleanup, after its review of this demonstration.
2.1 Facility Description
Facility K is a chemical manufacturing facility that manufactures petrochemical
products. Manufacturing of these products is performed in the eastern portion of
the property (Figure 2-1). The hazardous waste management area consists of the
following units:
• four wastewater treatment lagoons, numbered 1 through 4, and
• two landfill units, A and B.
A Part B permit application was submitted in the summer of 1985 covering the
operation of the lagoons and Landfill B and the closure of Landfill A.
2-1
-------
N>
I
ro
Agricultural
Town A
(2 miles)
Residential
LEGEND
• Production Well
O Upgradient Well
^lO^EIewation (feet. MSL)
X~V 0 1000 2000
* W Scale. Feet
Wastewater
Treatment
Lagoons
Eastern
Manufacturing
I Facilities
Manufacturing
FACILITY K
X-Corp. Facility
Mutufacturiiu Unit
Z-Corp. Faciliiy
Manufacturing Unit
2
m
&
-------
OSWER Directive 9481 00-11
The wastewater treatment lagoons receive wastewaters contaminated with
arsenic, benzene, chromium, methylene chloride, 1,1,1-trichloroethane, and
trichloroethylene and other hazardous constituents as described in Section C of the
Part B permit application. Presently, only three lagoons at a time receive
wastewater for treatment, allowing the sludge in the fourth lagoon todewaterand
dry prior to disposal. The active lagoons are rotated to allow sludge removal (and to
allow inspection and repair of the liner systems should this be required) at each
lagoon on an annual basis. The treated wastewater effluent is discharged via an
open ditch to Stream C which carries the effluent to River A (Figure 2-1).
Currently, the effluent discharged into the wastewater treatment lagoons
meets the criteria established in 40 CFR 268, Subpart D. The effluent discharged to
the ditch meets NPDES permit requirements established by the State. Monitoring
for compliance with the NPDES permit conditions is performed by a composite
sampler located in the effluent ditch near the lagoons. Effluent monitoring data
are presented in Section C, and the NPDES permit is presented in Appendix 1, of the
PartB permit application.
Prior to January 1985, the sludges from the treatment lagoons were placed in
Landfill A without drying. (No other materials were disposed of in Landfill A.)
However, disposal of sludges was discontinued in January 1985 because of
regulatory constraints on the disposal of bulk liquids in landfills, and Landfill A was
closed because interim status ground-water detection monitoring had detected
significant increases above background for the contaminants identified above.
Landfill B was built to receive non-liquid treatment lagoon sludge (that is, sludge
that passes the paint filter test).
In response to the corrective action order, process changes were made to
reduce contaminants in the wastewater and sludges, and the single-lined Lagoons 1
through 4 were retrofitted with double liners and leachate collection systems.
Retrofitting of the lagoons to meet minimum technology requirements was
completed in March 1987.
Ground-water detection monitoring, initiated in 1983, was extended in July
1985 to include the lagoons and Landfill B as part of the approved ground-water
2-3
-------
OSWER Directive 9481.00-11
assessment monitoring program under 40 CFR Part 265, Subpart F, and in response
to the minimum technology requirements for these hazardous waste
treatment/disposal units.
Additional facility descriptive information is presented in Section B of the Part
B permit application.
2.2 Approach to ACL Determination
Facility K is adjacent to River A, a large river in the southeastern United States.
Immediately underlying the facility is a silty clay layer approximately 10 to 20 feet
thick. Below this clay layer is the uppermost aquifer, composed of Pleistocene
terrace and alluvial deposits.
Five hazardous constituents have been detected in the ground water at
Landfill A and in lesser concentrations at the wastewater treatment lagoons north
of Landfill A. The plumes of constituents originate in the area of Landfill A and
Lagoons 1 through 4. The plumes are migrating toward the river, but have not
crossed the facility boundary. These plumes are discussed further in Section 3. Since
closure of Landfill A and retrofitting of the lagoons, the ground-water
concentrations of the hazardous constituents have decreased, and no leaks have
been detected at Landfill B or at the wastewater treatment lagoons.
For this demonstration several exposure pathways are evaluated, namely:
• Human exposure to drinking water obtained from either River A or
ground water,
• Combined human exposure to drinking water and aquatic organisms,
and
• Ecosystem exposure.
Allowable exposure levels are estimated for each human exposure pathway by
considering maximum contaminant levels (MCLs), carcinogenic effects at the 10-6
2-4
-------
OSWER Directive 9481 00-H
risk level, and systemic effects. Water quality criteria for acute and chronic exposure
to the ecosystem are also considered.
The POE is conservatively established between the POC and the leading edge
of the plumes. The lowest of the allowable exposure levels for each hazardous
constituent is selected as the maxirnum allowable exposure concentration to be met
at the POE. These maximum allowable exposure concentrations are then multiplied
by an attenuation factor (to account for the decrease in contaminant
concentrations between the POC and POE), yielding the proposed ACLs to be met at
the POC. The attenuation factor was empirically derived from ground-water
monitoring data, as discussed in Section 7.
2.3 Report Organization
This application is presented in eight sections: executive summary,
introduction, identification of ACL constituents, general information, geologic and
hydrologic information, exposure pathways, development of ACLs, and monitoring
program. The ACL criteria listed in 40 CFR 264.94 (b) are discussed within these
eight sections. Appendix A shows the correspondence between the regulatory
requirements and the location of material within this application. Appendix B
provides the chemical and physical properties of the hazardous constituents which
have exceeded background values in the ground water.
The discussion in these sections presumes a familiarity with Part I of EPA's ACL
guidance (EPA, 1987a) on information required in ACL demonstrations. The
discussion also assumes a familiarity with information in the Part B permit
application for this facility. Data that would appear in that document are not
reproduced in this case study except where they were deemed necessary for the
sake of clarity and continuity. Specific sections of the Part B permit application are
referenced throughout this application.
2-5
-------
OSWER Directive 9481.00-11
3.0 IDENTIFICATION OF ACL CONSTITUENTS
3.1 Hazardous Constituents in the Waste
Previous analytical work identified the 40 CFR 261 Appendix VIII constituents
present in the waste streams produced at Facility K (Section C of the Part B permit
application). These hazardous constituents, listed in Table 3-1, are expected to be
present in the waste streams generated in the facility's manufacturing process.
3.2 Extent and Degree of Contamination
Five Appendix VIII constituents have been found in ground water beneath the
facility downgradient of the hazardous waste units. These constituents are
benzene, chromium, methylene chloride, 1,1,1-trichloroethane, and
trichloroethylene. Appendix B describes the pertinent physical and chemical
properties of these constituents.
All ground-water monitoring wells installed at Facility K are shown in Figure
3-1. There are five background monitoring wells and thirty-six downgradient wells
including twelve assessment monitoring wells.
In 1984, several samples were taken from both aquifers downgradient of
Landfill A and analyzed for Appendix VIII constituents. The five constituents named
above were detected above background concentrations in the uppermost aquifer;
but not in elevated concentrations in the deeper aquifer. Similar chemical analyses
performed in 1986 on samples from the uppermost aquifer downgradient of the
wastewater lagoons showed elevated concentrations of the constituents. None of
the Appendix VIII constituents have been detected in the upgradient wells (see
Section F of the Part B permit application.)
Table 3-2 presents the maximum concentrations of the five constituents of
concern observed at monitoring wells screened in the uppermost aquifer. The
maximum concentrations observed are graphically portrayed in Figures 3-2 through
3-6 by contouring the data presented in Table 3-2. The contaminant plumes,
defined by maximum observed concentrations, extend from the southeast portions
3-1
-------
OSWER Directive 9481 00-1
TABLE 3-1.
APPENDIX VIII CONSTITUENTS PRESENT AT FACILITY K
Acetonitrile
Acrylonitrile
Aniline
Antimony
Arsenic
Barium
Benz (a) anthracene
Benzene
Beryllium
Bis (2
-------
OSWER Directive 9481 QQ-11
FACILITY K BOUNDARY
Eastern
Manufacturing
Facilities
24 25 26 27
LEGEND
• Detection Well (Compliance)
• Assessment Well
•••• Point of Exposure (POE)
KEY
21
'4*
0 100 200 300 400 500
csaess
Scale, Feet
Boundary
FIGURE 3-1. MONITORING WELL LOCATIONS AND "POEs"
3-3
-------
OSWER Directive 9481.00-11
TABLE 3-2.
MAXIMUM OBSERVED CONCENTRATIONS (mg/l) AT SAMPLING
LOCATIONS
Sample
Location
Monitoring
W«lh
MW-1
MW-2
MW-3
MW-4
MW-5
MW-6
MW-7
MW-8
MW-9
MW-10
MW-11
MW-1 2
MW-1 3
MW-1 4
MW-1 5
MW-16
MW-1 7
MW-1 8
MW-1 9
MW-20
MW-21
MW-22
MW-23
MW-24
MW-25
MW-26
MW-27
MW-28
MW-29
B«n£cn«
'8445
ND
NO
NO
0.016
0.051
0.112
0.033
0.005
0.012
0.045
0.064
0.027
0.009
0.017
0.032
0.039
0.018
0.007
0.01
0.018
0.017
0.009
0.006
0.019
0.007
NO
ND
ND
ND
1987
ND
ND
ND
0.013
0.042
0.093
0.027
0.005
0.009
0.037
0.057
0.026
0.006
0.017
0.027
0.03S
0.014
0.006
0.008
0.014
0.015
0.008
0.006
0016
0.005
ND
ND
NO
ND
Ctaomium
'84-85
NO
NO
ND
0.045
0.15
0.097
0.053
0.01
0.047
0.062
0.051
0.042
0.038
0.036
0.043
0.039
0.026
0.015
0.013
0.011
0.01
0.012
NO
0.016
0.017
ND
ND
NO
ND
1987
NO
ND
NO
0.043
0.136
0.093
0.048
0.009
0.043
0.06
0.047
0.038
0.04
0.032
0.039
0.035
0.024
0.014
0.011
NO
ND
0.01
NO
0.014
0.015
NO
ND
ND
ND
Methylen«
Chloride
'84-85
NO
ND
0.002
0.012
0.04
0.087
0.026
NO
0.018
0.035
0.049
0.021
0.008
0.013
0.025
0.031
0.014
0.007
0.008
0.014
0.013
0.007
0.005
0.014
0.005
ND
ND
NO
ND
1987
ND
ND
ND
0.01
0.036
0.08
0.024
NO
0.016
0.035
0.044
0.019
0.006
0.011
0.022
0.03
0.012
0004
0.003
0.013
0.013
0.005
0.001
0.013
ND
NO
NO
ND
ND
1.1,1-
Triehloro«than«
'84-85
ND
ND
NO
0.006
0.019
0.041
0.012
NO
0.008
0.016
0.023
0.01
NO
0.006
0.012
0.015
0.007
ND
ND
0007
0006
NO
NO
NO
ND
ND
ND
ND
ND
1987
NO
0.001
NO
0.004
0.014
0.04
0.012
NO
0.006
0.012
0018
0.008
NO
0.002
0.009
0.015
0.006
NO
0.001
0.005
0.004
0.001
NO
NO
NO
NO
ND
NO
0002
Trichloroethylene
'84-85
ND
NO
ND
NO
0.009
0.035
0.008
NO
NO
0.007
0011
NO
ND
NO
0.006
0.007
ND
NO
NO
NO
NO
ND
ND
ND
ND
NO
ND
ND
NO
'1987
NO
NO
NO
NO
0.008_
0.029
0.005
NO
NO
0.001
0.01
NO
NO
NO
0.003
0.007
NO
ND
NO
ND
ND
NO
NO
NO
ND
NO
ND
ND
NO
3-4
-------
OSWER Directive 9481.00-11
TABLE 3-2. (continued)
MAXIMUM OBSERVED CONCENTRATIONS (mg/l) AT SAMPLING
LOCATIONS
Sample
Location
Monitoring
Wells
MW-30
MW-31
MW-32
MW-33
MW-34
MW-35
MW-36
MW-37
MW-38
MW-39
MW-40
MW-41
Effluent
Ditch
Offsite
Stations*
S-1(R.A,
upstream)
S-2(R.A,
dwnstrm)
S-3 (wet-
lands)
XCorp
Well
Detection
Limits
AAS"
VOA"*
Benzene
'84-85
NO
0.015
0.05
0.058
0.006
NO
0.011
0.008
0.028
NO
0007
0.011
0.006
0.002
0.004
NO
0.002
0.001
1987
NO
0.012
0.04
0.056
0.005
NO
0.009
0.006
0023
NO
0.004
0.003
0.006
,
Chromium
'84-85
NO
NO
0.061
0.126
0.022
0.011
0.045
0.025
0.056
NO
0.022
0.015
0.029
0.012
0.012
NO
0.01
0.01
1987
NO
NO
0.056
0.115
0.02
0.011
0.040
0.020
0.051
NO
0.017
0.014
0.031
Methylene
Chloride
'84-85
NO
0012
0039
0.045
NO
NO
0.008
0.006
0.022
NO
0.005
0.009
0.006
NO
0.001
0.001
NO
0.001
1987
NO
0.011
0.034
0.041
NO
NO
0.004
0.005
0.021
NO
0.004
0.008
0.006
1,1,1-
Trichloroethane
'84-85
NO
0.006
0.018
0.021
NO
NO
NO
NO
0.006
NO
0.003
NO
0.064
0.008
0.007
0.003
0.003
0.001
1987
NO
0.003
0.013
0015
NO
NO
NO
NO
0005
NO
0001
NO
0.073
Trichloro«thylene
'84-85
NO
NO
0.024
0.031
NO
NO
NO
NO
0012
NO
0005
NO
0009
0.001
0.001
NO
NO
0.001
1987
NO
NO
0.020
0.026
NO -
NO
NO
NO
0.008
NO
0.003
NO
0.007
ND =
*
**
«*•
Not Detected
See Figure 5-1 for locations
Atomic Absorption Spectrophotometry
Volatile organic compound analysis by gas chromatography/mass spectrometry
3-5
-------
OSWER Directive 9481 00-11
FACILITY K BOUNDARY
Eastern
Manufacturing
Facilities
0 100 200 300 400 500
i i i
Scale, Fwt
\
LEGEND
• Detection Well (Compliant)
• Assessment Well
KEY
Boundary
FIGURE 3-2. ISOPLETHS FOR BENZENE (mg/l) BASED ON MAXIMUM
CONCENTRATIONS (1984 - 1985)
3-6
-------
OSWER Directive 9481.00-1
FACILITY K BOUNDARY
Eastern
Manufacturing
Facilities
LEGEND
• Ottection Well (Compliance)
• Assessment Well
KEY
0 100 200 300 400 500
E5E5S
Scale, Feet
Boundary
FIGURE 3-3. ISOPLETHS FOR CHROMIUM (mg/l) BASED ON MAXIMUM
CONCENTRATIONS (1984 - 1985)
3-7
-------
OSWER Directive 9481.00-11
FACILITY K BOUNDARY
Eastern
Manufacturing
Facilities
0 TOO 200 300 400 500
LEGEND
• Detection Well (Compliance)
• Assessment Well
FIGURE 3-4. iSOPLETHS FOR METHYLENE CHLORIDE (mg/l) BASED ON
MAXIMUM CONCENTRATIONS (1984 - 1985)
3-8
-------
OSWER Directive 9431 00-1
FACILITY K BOUNDARY
Eastern
Manufacturing
Facilities
0 100 200 300 400 500
EZ=5
Scale. Feet
LEGEND
• Detection Well (Compliance)
• Assessment Well
FIGURE 3-5. ISOPLETHS FOR 1,1,1-TRICHLOROETHANE (mg/l) BASED ON
MAXIMUM CONCENTRATIONS (1984-1985)
3-9
-------
OSWER Directive 9481.00-11
FACILITY K BOUNDARY
39
• 29
27
Landfill hj
,' ,
M I ^m
23
22
21
19
20
0 100 200 300 400 500
Scale, Feet
\
LEGEND
• Detection Well (Compliance
• Assessment Well
KEY
Soundary
FIGURE 3-6. ISOPLETHS FOR TRICHLOROETHYLENE (mg/l) BASED ON
MAXIMUM CONCENTRATIONS (1984 - 1985)
3-10
-------
OSWER Directive 9481 QQ-11
of both Landfill A and wastewater treatment Lagoons 2 and 3 and are somewhat
elliptical in shape. The approximate maximum and minimum lengths of the axes are
indicated in Table 3-3:
TABLE 3-3.
DIMENSIONS OF PLUMES
Location
Landfill A
Wastewater
Treatment
Lagoons
Constituent
Methylene Chloride
Trichloroethylene
Methylene Chloride
1,1,1 -Trichloroethane
Major Axis
NW-SE (ft)
1,280
720
840
580
Minor Axis
NE-SW(ft)
890
480
550
510
Although the plumes occur beneath Landfill B and the lagoons, the secondary
leachate collection systems have remained dry since their installation. Therefore,
the contaminant plumes appear to represent releases from Landfill A and past
releases from the lagoons. As evidenced from the maximum concentration maps,
the contaminant plumes are within the boundary of Facility K and have not reached
River A, the sensitive ecosystem of the wetlands near River A, Pond B, or the well at
X Corporation.
The concentrations of the six hazardous constituents of concern have been
declining with time (see Table 3-2). Thus, the contaminant plumes are decreasing in
size, and are now smaller than depicted in Figures 3-2 through 3-7.
The limited data available for the off-site well at X Corporation and data for
several surface water samples from the open effluent ditch and River A are also
reported in Table 3-2.
3-11
-------
OSWER Directive 9^81 00-11
4.0 GENERAL INFORMATION
This section provides a brief description of the site characteristics relevant to
this application. A more complete description of these characteristics is provided in
Section B of the Part B permit application for this site. The text that follows
describes land use, water use, and precipitation.
4.1 Land Use
Facility K is located in southern portion of County C in State D, on the
northwest bank of River A. This area of the State is highly industrialized, in part
because of a readily available source of water, River A. Industrial development
along the river is particularly high. As shown in Figure 2-1, the area surrounding the
facility supports industrial, residential, and agricultural land uses. There are
undeveloped wetlands on both banks of River A. (See Section 5.4 of this application
and the Part B permit application, Section B and Plate 3.) Agricultural lands are
north and west of Facility K. Immediately west of Facility K is Fadlity Y, which
manufactures chemicals. The X Corporation, a steel plate fabricating facility, shares
its northern and eastern boundaries with Facility K. The Z Corporation operates a
plating company on the opposite side of River A.
Town A, with a population of about 8,500 people, lies about 2 miles west of
Facility K. There is a small residential community of about 10 homes on the outskirts
of Town A's corporate limit, south of Facility Y and west of Facility K.
4.2 Water Use and Users
Ground water is a major source of both industrial and drinking water for the
region, and it is an important source of water for both industrial and domestic users
in the immediate vicinity of Facility K. Ground water is pumped from two aquifer
systems, the upper aquifer composed of Pleistocene terrace and alluvial sediments
(known locally as the alluvial aquifer) and the lower, Miocene aquifer. Both are
described in Section 5 of this application. The community well fields serving Town A
are 1-1/2 miles northwest of the town and three miles west of Facility K. Two of the
residences in the small community east of Town A are served by private wells; the
other eight are served by the Town A municipal water system wells. All ground-
water users with in 3.1 miles (5 kilometers) of Facility K are identified in Table 4-1.
4-1
-------
OS WE R Directive 9481.00-11
TABLE 4-1.
INVENTORY OF WELLS WITHIN 3.1 MILES (5 KM) OF THE FACILITY
Production
Well
Facility K
K-1
K-2
K-3
K-4
K-5
X Corporation
Z Corporation
Facility Y
Town A
Residence 1
Residence 2
Aquifer
Unit
c='
Alluvial
Miocene
Miocene
Alluvial
Alluvial
Alluvial
Alluvial/
Miocene
Alluvial
Alluvial/
Miocene
Alluvial
Alluvial
Pumping
rate (gpm)
30-50
75-100
150-200
75-100
30-50
350-500
300=450
350-500
500-600
10-20
10-20
Use
Industrial
Industrial/domestic
Industrial/domestic
Industrial
Industrial
Industrial/domestic
Industrial/domestic
Industrial/domestic
Domestic
Domestic
Domestic
The western manufacturing area of Facility K has a well field that pumps from
both the alluvial and Miocene aquifers, as does the well at the 2 Corporation
property. At both Facility K and the Z Corporation, industrial process water is
obtained from both aquifers, but domestic water is obtained only from the Miocene
aquifer. In contrast, the wells at X Corporation and Facility Y pump only from the
alluvial aquifer and use this water for both industrial and domestic purposes.
Ground-water withdrawal in this state is governed by the common law-
reasonable use system of allocation. There is little or no regulation of withdrawals
by private, industrial or agricultural users.
Surface water in the area includes River A, Pond B, and Stream C. River A is
used for recreation and recreational fishing. Pond B is located on the X Corporation
property and is used for the discharge of cooling water and industrial wastewaters
under an NPDES permit. Stream C is dammed on Facility K's site and the impounded
water is used in the manufacturing process at Facility K.
4-2
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OSWER Directive 9481.00-11
Industries upstream of Facility K have contributed hazardous constituents to
the river (Table 3-2). The slight increases in constituent concentrations observed in
the wetlands adjacent to Facility K and downstream of Facility K are attributable to
the NPDES discharges from Facility K and X Corporation, as well as other industries
along the eastern side of River A.
Conversations with County Planners indicate surface and ground-water use in
the area is unlikely to change much in the next twenty years (Section B of the Part B
permit application).
4.3
Precipitation
The climate of the area is very humid and subtropical. The average annual
precipitation is roughly 59 inches, with December through April being the wettest
months and August through November the driest. Table 4-2 presents the average
monthly precipitation observed at an airport approximately eight miles west of the
facility for the years 1955 through 1985.
TABLE 4-2.
AVERAGE MONTHLY PRECIPITATION*
Month
January
February
March
April
May
June
July
August
September
October
November
December
Total
Average Rainfall
(inches)
4.84
4.74
6.54
5.66
4.63
4.99
5.40
7.16
4.83
4.38
2.54
3.65
59.36
Source: NOAA, 1986.
* Based on 30 years of records.
4-3
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OSWER Directive 9481 00-11
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION
This section summarizes geologic and hydrologic characteristics pertinent to
this application. A complete characterization of the geology and hydrology is
presented in the Part B permit application, Sections B and D.
Facility K is located adjacent to River A in the southeastern United States. The
site topography consists of rolling hills with a general southeast gradient toward
the river. The edge of the terrace on which most of Facility K is located terminates
east and south of Landfills A and B (Figure 5-1), where the ground slopes steeply to
the floodplain of River A.
5.1 Regional Geology
The site is in the Gulf Coastal Plain Province. The characteristic Gulf Coastal
Plain strata are present as a series of overlapping layers that dip to the south toward
the Gulf of Mexico. These deposits are made up of soft unconsolidated sand, gravel
and clay, and consolidated or semiconsolidated calcareous sand.
The surficial materials in the general vicinity of Facility K are alluvial and
terrace deposits of Pleistocene age. These are underlain by undifferentiated
Miocene deposits consisting of sand, clay, and gravelly sand. The unconsolidated
units extend to a depth of over 700 feet. The Miocene deposits are underlain by
limestone deposits of Oligocene age.
Water-bearing units are present in all of these formations, although water
from the Oligocene limestone tends to be high in total dissolved solids (TDS).
Regional ground-water users pump from both the Pleistocene and the Miocene
units. Well yields in these two units are high, generally capable of 500 gpm, and the
water quality is well within all federal and state drinking water standards. The
Miocene unit, however, has higher TDS concentrations and is therefore less valued
as a source of drinking water.
5-1
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OSWER Directive 9481.00-11
Wastewater
Treatment
Lagoons
Western
Manufacturing I
• Facilities
and Well Field
LEGEND
* Surface Water Sample Point
O Upgradient Well
Elevation (feet, MSL)
FIGURE 5-1. SITE TOPOGRAPHY
5-2
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O5WER Directive 9481 00-1
5.2 Site Geology
The southeastern portion of Facility K is on the western floodplain of River A.
The stratigraphy beneath the site has been identified by a series of monitoring wells
and is summarized in two geologic cross sections, the locations of which are
indicated in Figure 5-2. The cross/sections are presented in Figure 5-3. Additional
cross sections and the complete boring logs are presented in Sections B and D of the
Part B permit application.
Thesurficial material is a Pleistocene clay that is 10 to 20 feet thick beneath the
facility and thinner (possibly vanishing in some places) near River A. This clay is
underlain by 30 to 50 feet of Pleistocene alluvial deposits of interbedded layers of
sand, gravel, and clay. Elevation irregularities of the top of the underlying
sediments, which represents an ancient erosional surface, influence the thickness of
Pleistocene alluvial sediments.
The sediments underlying the Pleistocene sediments are Miocene clays and
sandy clays with thicknesses ranging from 30 to more than 100 feet overlying 600
feet of alternating layers of Miocene sand, clay and gravel.
5.3 Ground-Water Hydrology
The site is underlain by two hydraulically separate aquifers, an upper, alluvial
aquifer of Pleistocene sediments and a lower, Miocene aquifer, separated by the
Miocene clays.
The upper, alluvial aquifer is recharged by rainfall and infiltration from
streams and lakes. Ground water in it flows under semiconfined conditions to the
southeast toward the river. The saturated thickness, as shown in Figure 5-4, varies
between 25 and 50 feet. The aquifer may be hydraulically connected to wetland
areas east and south of the facility. Few tests have been performed in this area, but
nearby borings (presented in Section D of the Part B permit application) show that
the surficial clay thins to less than 3 feet in this area. A horizontal flow net of this
aquifer unit is presented as Figure 5-5.
5-3
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OSWER Directive 9481 00-11
FACILITY K BOUNDARY
Eastern
Manufacturing
Facilities
LEGEND
• Detection Well (Compliance)
• Amument Well
G Upgradient Well
^ Elevation (feet, MSL)
0 100 3)0 300 400 500
FIGURE 5-2. LOCATION OF CROSS SECTIONS
5-4
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OSWER Directive 9481 00-11
o
£
HI
Ul
o
Ul
-50 -J
250
Scale, Feet
500
FIGURE 5-3. CROSS SECTIONS A-A' AND B-8'
5-5
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OSWER Directive 9481.00-11
1 FACILITY K BOUNDARY
i
/ i
/
J
f V
I
u,
j
Reservoir :;A
f 30
/
/
<-v
Lagoon
1
Lagoon
4
A
\
\
Lagoon
2
\
\
Lagoon
3
£4
s
Bj
33
] 31 32
Eastern
Manufacturing
Facilities
• 35
^
^^ ***
36
•37
• 38
i
i
»
1
1
0 100 200 300 400 500
Scale, Feet
LEGEND
• Detection Well (Compliance)
• Assessment Well
KEY
^
vM/A
\^ '&****/A
^~W>
t^^rt'A
Boundary
FIGURE 5-4. SATURATED THICKNESS OF THE ALLUVIAL AQUIFER (feet)
5-6
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OSWER Directive 9481 00-1
FACILITY K BOUNDARY
LEGEND
• Detection Well (Compliance)
• Assessment Well
-i^-Flow Line * I
^•Ground-water Elevation (Faet, MSL)
0 100 200 300 400 500
'4*
Not*: Ground-witcr ilcvation is in f««t. MSL.
Scale. Feet
Boundary
FIGURE 5-5. FLOW NET FOR THE ALLUVIAL AQUIFER
5-7
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OSWER Directive 9481.00-11
The underlying Miocene aquifer is a true confined unit. Section D of the Part B
permit application demonstrates the independence of these units by presenting the
results of pump tests and slug tests performed at the site and at several points
downgradient of the site. The 30- to 100-foot-thick Miocene clay layer was shown
by evaluation of the slug test data to have a hydraulic conductivity on the order of
10-7 cm/sec (Table 5-1).
The potentiometric surface in the Miocene aquifer has been significantly
influenced by pumping at Facility K industrial/domestic wells. Prior to these
activities, the potentiometric surface in the Miocene aquifer was higher than that in
the alluvial aquifer. Today, due to the pumping at Facility K, head elevations in the
Miocene unit are below those in the alluvial unit. The downward head differential
is 15 to 20 feet near the production wells and 5 to 8 feet beneath the waste
management units.
Hydraulic parameters of the alluvial aquifer beneath the site have been
defined through field tests at the monitoring wells. Longitudinal and transverse
dispersivities were measured to be 60 feet and 240 feet, respectively. These
parameters agree with field tests for similar media over similarly large scales. The
hydraulic conductivity tests showed values to range from 1.2 x 10-3 to 9 x 10-2
cm/sec in the alluvial aquifer while the upper clay layer is measured at 4 x 10-6 to 2 x
10-4 cm/sec and the Miocene clay was measured at 1 x 10=7 to § x 10-8 cm/sec. Both
pump tests and slug tests were used. A summary of these tests is presented in Table
5-1. More complete data and analysis are available in Section D of the Part B permit
application.
The hydraulic conductivity of the Miocene clay is at most 1.0 x 10-7 cm/sec. The
low hydraulic conductivity and the thickness (30-100 feet) of the clay should protect
the underlying Miocene aquifer from contamination from the alluvial aquifer.
5.4 Surface Water Hydrology
River A is the dominant surface-water feature in the vicinity of Facility K. The
river flows from northeast to southwest, eventually emptying into the Gulf of
Mexico. As indicated in Figure 4-1, wetlands dominate the areasadjacent to the
5-8
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OSWER Directive 9481 00-1
TABLE 5-1.
HYDRAULIC CONDUCTIVITY TESTS
Strata
Surficial clay
Alluvial aquifer
Miocene clay
Miocene aquifer
Test Type
piezometer
pump-
drawdown
pump-recovery
piezometer
piezometer
pump-recovery
No.
of
Tests
6
6
2
5
3
3
Range of Values
(cm/sec)
4x 10-6 to 2 x 10-4
1.2 x 10-3 to 9 x 10-2
4.9x10-3 to 2.1 x10-2
3.3x10-3 to 1.7x10-2
5x10-8 to 1 x10-7
9.7x10-4 to 1.8x 10-2
Monitoring
Wells
3,4,5,7,32,
33
6, 12, 17,
25,32
7,17
10,15,24,
31,39
8,27,31
11M,21M,
38M
river. Between the river and the terrace, the terrain is flat and contains wetland
areas that can extend for over a mile along the bank. This area forms the 100-year
floodplain.
The flow in River A has been measured since 1950 at a gauging station 20 miles
upstream of the facility. The flow during the period between 1950 and 1984
averaged 21,000 cfs with a record low flow of 902 cfs observed on June 28,1966 and
a maximum of 49,000 on January 6, 1955. The United States Army Corps of
Engineers has established a policy to maintain a minimum flow of 1500 cfs along
this reach of River A. As described in the Part B permit application, this is achieved
by regulating flow from a series of upstream dams used for hydroelectric power
generation.
The other surface water body of interest to this application is Pond B, located
on the X Corporation property south of Facility K. This pond receives cooling water
and wastewater discharges from the X Corporation's manufacturing facility. It is
connected to the river by a narrow channel at its southeastern edge.
The Facility K site is dissected by several small streams (A, B and C) that direct
runoff from the site southeast toward the river. A small reservoir has been created
on site by damming stream C. An effluent ditch from the Facility K wastewater
5-9
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OSWER Directive 9481.00-11
treatment unit runs from Lagoon 4 to Stream C .cross a relatively flat portion of this
site. Neither this effluent ditch nor the streams at the facility cut through the
surficial clay unit.
5-10
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OSWER Directive 9481 00- n
6.0 EXPOSURE PATHWAYS
This section identifies and characterizes the potential exposure pathways by
which .contaminants released to the ground water from the waste management
units in the eastern part of Facility. K may pose a threat to human health and the
environment. Ground-water monitoring has shown that five hazardous
constituents are migrating from facility K's waste management units toward River
A and the southeastern property boundary. Potential receptors include (a) human
exposure to contaminated water from drinking water wells and River A, and to
contaminated aquatic life from River A and (b) ecosystem exposure to contaminants
in the wetland area and River A. Exposure to contaminants released from Facility K
may occur at various points along these paths, but due to attenuation of the plume,
the critical points of exposure will tend to be closer to the sources of .the
contamination.
In the sections that follow, these potential exposure pathways are evaluated
and allowable exposure levels calculated for each of the five hazardous constituents
of concern. From these values, maximum allowable exposure concentrations are
selected as criteria to be met at the Point of Exposure (POE) by Facility K (discussed
in Section 7).
6.1 Potential Human Exposure
No current human exposures to contaminants from the hazardous waste
management units at Facility K have been identified, but humans could become
exposed to the contaminants by ingestion of water and/or aquatic organisms. The
paths of possible human exposure considered for this demonstration are:
• Ingestion of contaminated drinking water from wells developed in the
alluvial (uppermost) and/or Miocene aquifers,
• Ingestion of contaminated drinking water from River A, and
• Combined ingestion of contaminated aquatic organisms and drinking
water from River A.
6-1
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OSWER Directive 9481 00-11
As noted in Sections 3 and 5, human exposure to drinking water from wells is
unlikely for the following reasons:
• The low hydraulic conductivity and thickness of the Miocene clay protect
the underlying Miocene aquifer from contaminants released to the
alluvial aquifer,
• Contamination is limited to the alluvial aquifer and is confined to the
Facility K property, and
• Onsite and offsite process and drinking-water wells are not down-
gradient of the contaminant plumes.
Human exposure to contaminated water or aquatic life in River A is also
believed unlikely because:
• No contaminant plume has reached River A or the wetland areas
bordering the river, and
• The concentration of all five hazardous constituents is now decreasing
following closure of Landfill A and retrofitting of the lagoons to
minimum technology requirements.
6.2 Potential Environmental Exposure
Two environments were initially considered to be at risk of exposure to the
hazardous constituents released from the Facility K waste management units.
These environments are the wetlands bordering River A and River A itself. As noted
above, hazardous constituents are unlikely to reach either environment.
Several endangered or threatened species have been known to inhabit the
river and wetland ecosystems in this region of the southeastern United States. Fish
species include the Snail Darter, Slackwater Darter, Amber Darter, and Spotfin
Chub. Terrestrial species include the Eastern Indigo Snake.
6-2
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OSWER Directive 9481.00-11
None of these species were identified in the biological analysis of the site.
According to the Fish and Wildlife Service, none of these species have been
identified in the general vicinity of the site, and none are suspected to be acutely
sensitive to the six hazardous constituents (see the correspondence from the Fish
and Wildlife Service reproduced in Appendix 5 of the Part B permit application).
6.3
Maximum Allowable Exposure Concentrations
The critical exposure pathways identified above include (a) human ingestion
of water; (b) combined human ingestion of aquatic organisms and water; and (c)
ecosystem exposure. Allowable exposure concentrations are established below for
each of these pathways. From these values, maximum allowable exposure
concentrations are selected for each hazardous constituent for use as criteria to be
met at ground-water monitoring wells at the POE.
6.3.1 Ingestion of Water
According to the ACL guidance, maximum contaminant levels (MCLs) serve as
allowable exposure levels for human ingestion of drinking water. Four of the
hazardous constituents have MCLs established through the Safe Drinking Water Act
(EPA, 1980a; 1982; 1987b). The MCLs for these four hazardous constituents are
listed in Table 6-1.
TABLE 6-1.
MAXIMUM CONTAMINANT LEVELS
Constituent
Benzene
Chromium
1,1,1-Trichloroethane
Trichloroethylene
MCL (ug/l)
5
50
200
5
6-3
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OSWER Directive 9481.00-11
An MCL has not been established for methylene chloride. However, this
compound has been classified as a probable carcinogen as well as exhibiting
systemic toxk properties. When a constituent has both a carcinogenic effect and a
systemic toxic effect, the allowable concentration level should be based on the
effect resulting in the lower concentration. Allowable exposure levels are
estimated below on the basis of carcinogenic potency and a risk value, and on the
basis of a reference dose associated with its systemic toxicity (EPA, 1987a; Section 9).
Methylene chloride has an oral carcinogenic potency factor (PF), or slope
factor, of 0.0075 [mg/kg/day]-1 (IRIS data base presented in Appendix B). As noted
by EPA (1987a), a PF can be used to estimate a risk specific dose (RSD; a risk-specific
allowable exposure level) that corresponds to a particular statistical excess lifetime
cancer risk value. Most exposure assessments consider risk values ranging from 10-7
to 10-4, with 10-6 being the point of departure. Thus, for a 70-kilogram adult who
consumes 2 liters of water per day, the RSO allowable exposure level at the 10-6 risk
value is estimated by the following formula:
Allowable Exposure Level (RSO) - Weight x Risk Value (6-1)
PF x Water Ingestion Rate
= 70x10-6 a 0.005 mg/l.
0.0075 x 2
Using the above equation, the RSD allowable exposure level for methylene chloride
with an excess lifetime cancer risk level of 10-6 is estimated to be 5 ug/l.
The allowable exposure level associated with the systemic toxic properties of
methylene chloride can be estimated using the verified reference dose (RfD) of
0.060 mg/kg/day provided in the IRIS data base (Appendix B). In equation 6-2
below, it is assumed that a 70-kilogram adult is exposed to methylene chloride by
drinking 2 liters of water per day:
Allowable Exposure Level (RfD) = Weight x RfD (6-2)
Water Ingestion Rate
= 70x0.060 = 2.1 mg/l.
2
6-4
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OSWER Directive 9481.00-11
This method yields an allowable drinking water exposure level of 2,100 ug/l for
methylene chloride, which is less protective than the level (5ug/l) calculated using
equation 6-1.
6.3.2 Ingestion of Water and Aquatic Organisms
Human exposure levels for ingestion of both water and fish have been
published in the "Quality Criteria for Water, 1986" (EPA, 1986a) for all constituents
detected except methylene chloride. The value of methylene chloride can be
determined by using modified versions of the equations above.
These equations can be modified to account for ingestion of both water and
aquatic organisms by considering the aquatic bioconcentration factor (BCF) for the
hazardous constituent and average daily consumption (DC) of aquatic organisms, as
shown in equations 6-3 and 6-4.
Allowable Exposure Level (RSD;bcf) -• Weight x Risk Level (6-3)
PF x [Water Ingestion Rate + (DC x BCF)]
Allowable Exposure Level (RfD;bcf) = Weight x RfD (6-4)
[Water Ingestion Rate + (DC x BCF)]
The allowable exposure levels for drinking water and eating aquatic organisms
contaminated with methylene chloride are calculated below using equations 6-3
and 6-4 with a DC of 6.5 g/day (0.0065 kg/day), a BCF of 0.91 I/kg [EPA, 1986b], and
the appropriate values of Risk Level, PF, and RfD.
Allowable Exposure Level (Rso;bcf) = 70x10-6
0.0075[2 -i- 0.0065(0.91)]
0.005 mg/l.
6-5
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OSWER Directive 9481 00-11
Allowable Exposure Level (RfD;bcf)
70x0.060
[2 + 0.0065(0.91)]
2.09mg/l.
Allowable exposure levels for combined ingestion of both contaminated
water and aquatic organisms are provided in Table 6-2. Those combined levels for
benzene, chromium, 1,1,1-trichloroethane, and trichloroethylene are based on
"Quality Criteria for Water, 1986" (EPA, 1986a). However, the combined allowable
exposure level for methylene chloride presented in Table 6-2 is based on the
carcinogenic level calculated with equation 6-3, as it is more protective of human
health than the systemic toxicity based level calculated with equation 6-4 (5 ug/l vs
2090 ug/l).
TABLE 6-2.
ALLOWABLE EXPOSURE LEVELS FOR INGESTION OF
WATER AND AQUATIC ORGANISMS
Constituent
Benzene
Chromium
Methylene Chloride
1,1,1 -Trichloroethane
Trichloroethylene
Combined Allowable
Exposure Level (ug/l)
H'l
50m
5U!
18.400IM
3di
6.3.3
Ml Source: Quality Criteria for Water, 1986 [EPA, 1986b]
[2! Calculated using equation 6-3
Ecosystem Exposure
Acute and/or chronic exposures of freshwater ecosystems have been
established for four of the five hazardous constituents (benzene, chromium,
methylene chloride, and trichloroethylene) (EPA, 1986a and IRIS data base). These
criteria are used as allowable ecosystem exposure levels. Where needed, chronic
criteria can be estimated from the acute criteria by using a factor of safety of 100
(derived from an acute to chronic ratio (ACR) of 10 and a species sensitivity
uncertainty factor (SSUF) of 10). This procedure is discussed in detail in the EPA
6-6
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OSWER Directive 9431 00-1 '
document entitled "Technical Support Document for Water Quality-based Toxics
Control,"Box 3.4 (EPA, 1985).
The allowable freshwater ecosystem level for acute exposure to 1,1,1-
trichloroethane is based on the water quality criteria for trichlorinated ethanes.
The chronic level for this compound was derived by using a safety factor of 100 as
discussed above.
The allowable acute and chronic freshwater ecosystem exposure levels used in
this demonstration are listed in Table 6-3.
TABLE 6-3.
ALLOWABLE FRESHWATER EXPOSURE LEVELS
Constituent
Benzene
Chromium
Methylene Chloride
1,1,1 -Trichloroethane
Trichloroethylene
Allowable Freshwater Exposure Levels
Acute (ug/l)
5300m
16H I
11,000121
18,000n,4l
45,000(11
Chronic (ug/l)
53(31
11[U
110(31
180(31
21,900(11
in Source: Water Quality Criteria for Water, 1986 [EPA, 1986b]
[2] Source: IRIS data base
[3] Acute level divided by 100
w Level fortriehlorinated ethanes
6.3.4 Maximum Allowable Exposure Concentrations
The allowable exposure levels derived above are summarized in Table 6-4. The
maximum allowable exposure concentration for each of the five hazardous
constituents was established by first selecting the lowest human exposure level,
then comparing that value to the lowest ecosystem exposure level. The lower of
these two values was then chosen as the maximum allowable exposure
concentration for the specific hazardous constituent being evaluated. The
maximum allowable exposure concentrations are criteria to be met in the ground
water at the Point of Exposure (POE), as described in Section 7
6-7
-------
oo
TABLE 6-4.
MAXIMUM ALLOWABLE EXPOSURE CONCENTRATIONS
Chemical & CAS No.
Benzene
71-43-2
Chromium
7440-47-3
Methylene Chloride
75-092
1,1.1 -Trichloroethane
711-5-6
Trichloroethylene
79-01-6
MCLM1
(ug/i)
5
50
200
5
Human Exposures (pg/l)
Drinking
Water
NAI2I
NAI2I
5U1
NAUi
NAI21
Drinking
Water and
Fish
Ingestion
113)
50131
SK51
3.10015.81
3131
Ecosystem Exposures
(M9/D
Acute
5300131
1613!
11,000161
18.000I3-9J
45.000PI
Chronic
53131
11131
110171
180171
21.900131
Maximum Allowable
Exposure
Concentration
(wg/i)
1
D
11
5
200
3
ID Maximum Contaminant Level (EPA, 1980a, 1982; 1987b).
12) Not Applicable; MCL is available
131 Source: Water Quality Criteria for 1986 (EPA, 1986b).
I4) Calculated using current carcinogenicity (PF) data and a risk level of 10 6 as presented in the IRIS data base.
IS) Daily consumption (DC) and bioconcentration factor (BCF) from EPA (1980b and 1986b)
I6) Source: IRIS data base.
I7) Acute value divided divided by 100.
IB) Calculated value using current systemic toxicity (Rf D) data presented the IRIS data base
19) For trichlorinated ethanes.
m
70
ft
IB
O
9
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OSWER Directive 9481.00-11
ACL
CASE STUDY 2
-------
OSWER Directive 948' 30-'
7.0 DEVELOPMENT OF ACLs
ACLs are requested for benzene, chromium, methylene chloride, 1,1,1-
trichloroethane and trichloroethylene. The requested ACLs are based on the
maximum allowable exposure concentrations developed in Section 6.0 of this
application, and on an attenuation factor derived below.
The ACL is established at the Point of Compliance (POC). However, in some
cases a maximum allowable exposure concentration is set at the Point of Exposure
(POE) downgradient of the POC, and attenuation of contaminants between the POC
and the POE is considered in establishing the ACL. At a Case 2 site (contamination of
useable ground water is confined to the site), the POE is assumed to be no farther
from the POC than the outer edge of the existing plume. However, in accounting
for the attenuation between the POC and the POE, the concentrations in the plume
should not be allowed to in-crease above the maximum allowable exposure
concentration.
Facility K meets the definition of a Case 2 site. Thus, the ACL may be calculated
for the POC by considering the maximum allowable exposure concentration at the
POE, then accounting for the attenuation of the hazardous constituents between
the POC and POE. For Facility K the POE was set to be slightly within the plume
boundary. Because there are two distinct plumes with separate POCs and POEs at
Facility K (Figure 3-1), ACLs are proposed for both the lagoon POC and for the
landfill POC for each of the five hazardous constituents. See Figure 3-1 for the
location of the POEs and Figures 3-2 through 3-6 for the plume boundaries.
Attenuation of hazardous constituents was evaluated using the
concentrations of contaminants along the axes of the plumes (see Table 3-2). Two
procedures were used: a method of simple ratios and analytical ground-water
modeling.
Table 7-1 presents the data used to derive the attenuation factor by the
method of simple ratios. Maximum concentrations for each hazardous constituent
observed at the POC during 1984-1985 monitoring are reported under the "POC"
column headings for the lagoon and landfill areas of Facility K. Similarly,
7-1
-------
TABLE 7-1.
DEVELOPMENT OF ATTENUATION FACTOR
Constituent
Benzene
Chromium
Methylene
Chloride
1,1,1-
Trichloroethane
Trichlorethylene
1984-1985
Maximum Concentration (yg/l)
POC
Lagoons
58
126
45
21
31
Landfills
112
150
87
41
35
POE
Lagoons
11
25
9
3
5
Landfills
18
13
14
7
<1.0
Attenuation Factor
by Simple Ratios
Lagoons
5.3
5.0
5.0
7.0
6.2
Landfills
6.2
11.5
6.2
5.8
>35.0
Attenuation Factor
by Ground-water
Modeling
Lagoons
5.5
6.2
5.4
6.4
8.2
Landfills
5.9
9.9
7.0
7.5
25.0
m
3D
O
o
o
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OSWER Directive 9481 00-11
the maximum concentrations at the lagoon and landfill POEs for the same time
period are reported under the "POE" heading. The attentuation factors were
calculated by dividing the POC values by their corresponding POE values. In all
cases, the maximum concentrations measured at the POE in 1984 and 1985 were at
least a factor of 5 less than the POC concentrations, with a average decrease of
about sixfold (Table 7-1). Attenuation factors were also calculated from the 1987
data (Table 3-2), resulting in an average attenuation factor of about 8.0 and a
minimum attenuation factor of 5.0. The second method used to calculate
attenuation factors is described, and the results provided, in Appendix 6 of the Part
B permit application. The model is based on the rate of transport of contaminants
and considers adsorption and dispersivlty. The attenuation factors calculated by
this method are presented in the Part B permit application and are reproduced in
Table 7-1. For this demonstration, a conservative attenuation factor of 4 was
chosen.
For benzene, chromium, methylene chloride, and trichloroethylene, the
proposed ACLs were developed by multiplying the maximum allowable exposure
concentration by the attenuation factor. For example, the maximum allowable
exposure concentration for chromium is 11 ug/l (Table 6-4). This value multiplied by
the attenuation factor provides a proposed ACL of 44 ug/l (11 ug/l x 4 = 44 ug/0-
The proposed ACLs for these four constituents are less than their maximum
concentrations measured at either the lagoon or landfill POC in 1987 (Table 7-2).
To prevent the plume from expanding, the ACLs for 1,1,1-trichloroethane
were not calculated as just described. If the maximum allowable exposure
concentration (200 ug/0 for this hazardous constituent is multiplied by the
attenuation factor (4) the result (800 ug/0 is greater than the maximum
concentrations observed at the lagoon and landfill POCs in 1987 (15 and 40 ug/l,
respectively;" see Table 7-2). Therefore, for 1,1,1-trichloroethane, the proposed
ACLs are set equal to the maximum POC concentrations observed in 1987. This
procedure conforms with the guidance provided by EPA(1987a).
As may be noted from Table 7-2, further corrective action may be required for
benzene, chromium, methylene chloride and trichloroethylene because their
concentrations at the POC exceed their proposed ACLs.
7-3
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TABLE 7-2.
PROPOSED ALTERNATE CONCENTRATION LIMITS
Constituent
Benzene
Chromium
Methylene
Chloride
1,1.1-
Trichloroethane
Trichloroethylene
Maximum
Allowable
Exposure
Concentration ID
(ug/O
1
11
5
200
3
Attenuation
Factor
4
4
4
4
4
Proposed
ACL
(ug/0
Lagoons
4
44
20
15P!
12
Landfills
4
44
20
40(3)
12
Maximum
Concentration at
POCin1987l2]
(lig/D
Lagoons
56
115
41
15
26
Landfills
. 93
•c
136
80
40
29
HI From Table 6-4.
12] From Table 3-2.
13] Proposed ACLs established at maximum concentration measured in 1987 at their respective
POCs.
a
o
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OSWER Directive 9481.00-11
8.0
8.1
MONITORING PROGRAM
Ground-Water Monitorinq
A ground-water monitoring program has been in effect at Facility K since
1983. Analytical results of samplesrcollected from the monitoring wells installed for
detection and assessment mdnitoring under 40 CFR 265 indicate that the
concentrations of the five constituents are decreasing and that the plumes are
shrinking. Under 40 CFR 264, compliance monitoring is required at the POC.
Continued monitoring is also deemed necessary at the POE to verify the
assumptions used to derive the ACLs in Section 7. The compliance monitoring
system is described in detail in Section F of the Part B permit application. The
locations of the POC and POE monitoring wells are shown on Figure 3-1.
The POCs are at the edges of the monitored units, as required under 40 CFR
264.95. As described in Sections B and C of the Part B application, the present
interim status detection monitoring wells will serve as the compliance monitoring
wells (Figure 3-1). Thus, the POCs will be marked by the monitoring wells listed in
Table 8-1.
TABLE 8-1.
POC MONITORING WELLS
Facility
Landfill A
Landfill B
Lagoons 1-4
POC Monitoring Wells
MW-4throughMW-8
MW-24 through MW-28
MW-31 through MW-34
At a Case 2 site, the POE may be set as far from the POC as the leading edge of
the plume. For this demonstration, it is proposed to establish the POE as shown in
Figure 3-1. Comparison with the plume maps provided in Section 3 shows that the
location of the POE is within the boundary of the plume. The monitoring wells
marking the POE are shown in Table 8-2.
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OSWER Directive 9481 00-11
TABLE 8-2.
POE MONITORING WELLS
Facility
Landfill A
Landfill B
Lagoons 1 -4
POE Monitoring Wells
MW-19 through MW-23, and
MW-27
Not Applicable*
MW-39 through MW-41 and
MW-37
Landfill B is not leaking hazardous constituents
to the ground water.
The POCs will be monitored quarterly for the five constituents and annually
for ail Appendix IX constituents. Compliance monitoring will continue at the
lagoons for the active life of the units and at Landfill A until the ground-water
protection standard has not been exceeded for three consecutive years.
The POEs will be monitored annually for the five constituents that have been
detected until concentrations drop below the detection level. As the plumes shrink,
monitoring will be shifted closer to the units and will cease when the plumes are no
longer detectable.
Background wells in both alluvial and Miocene aquifers will be monitored
annually for the five constituents, as will a Miocene well downgradient of Landfill A
and each of of the lagoons (MW-21M and MW-38M). Ground-water levels will be
measured at the same time and ground-water flow paths determined. Current
ground-water levels and well elevations are shown in Section D of the Part B permit
application.
The monitoring program will be expanded, as appropriate, if concentrations
of any hazardous constituents are found to be increasing or if either plume appears
to be expanding.
Corrective action under the Corrective Action Order has been completed.
However, constituent concentrations at the POC are currently above the proposed
ACL limits for all of the hazardous constituents of concern, except 1,1,1-
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OSWER Directive 9481.00-11
trichloroethane. It is understood that EPA will evaluate the need for additional
corrective action after its review of this demonstration.
8.2 Other Monitoring
Monitoring will continue at offsite stations and at the onsite effluent ditch on
an annual basis (see Table 3-2). • Samples will be analyzed for the five constituents
that have been detected.
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OSWER Directive948l.QO-11
REFERENCES
EPA (U.S. Environmental Protection Agency), 1980a. "Environmental Protection
Agency National Primary Drinking Water Regulations, 40 CFR Part 141,
SubpartB," Federal Register:45:47342. August 17.
EPA (U.S. Environmental Protection Agency), 1980b. Ambient Water Quality
Criteria for Chlorinated Ethanes, EPA/440-5-80-029, Washington, D.C.,
October.
EPA (U.S. Environmental Protection Agency), 1982. "Environmental Protection
Agency National Primary Drinking Water Regulations, 40 CFR Part 141,
SubpartB," Federal Register47:10998. March 12.
EPA (U.S. Environmental Protection Agency), 1985. Technical Support Document for
Water Quality-Based Toxic Control, Office of Water, Washington, D.C.,
September.
EPA (U.S.Environmental Protection Agency), 1986a. Quality Criteria for Water. 1986.
EPA/440-5-86-001, Washington, D.C., May.
EPA (U.S. Environmental Protection Agency), 1986b. Superfund Public Health
Evaluation Manual. EPA/540-1-86-060, Office of Emergency and Remedial
Response (OERR), Washington, D.C., October.
EPA (U.S. Environmental Protection Agency), 1987a. Alternate Concentration Limit
Guidance. Part 1-ACL Policy and Information Requirements. EPA/530-SW-87-
017, OSWER, Washington, D.C, July.
EPA (U.S. Environmental Protection Agency), 1987b. "National Primary Drinking
Water Regulations," Federal Register 52:25690-25717, July 8.
NOAA (National Oceanic and Atmospheric Administration), 1986. Local
Climatoloqical Data, Annual Summaries for 1985, Part II - Southeastern Region.
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OSWER Directive 9481.00-11
Other Resource Documents
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Chromium, EPA/440-5-84-029, Washington, D.C.January, 1985.
U.S. Environmental Protection Agency, "Ambient Water Quality Criteria
Documents; Availability". -Federal Register 45:79313-79357, November 28,
1980.
U.S. Environmental Protection Agency, Health Effects Assessment for Benzene.
ECAO-CIN-HO-37, Environmental Criteria and Assessment Office, Cincinnati,
Ohio, September, 1984.
U.S. Environmental Protection Agency, Health Effects Assessment for Methylene
Chloride. ECAO-CIN-HO-28, Environmental Criteria and Assessment Office,
Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Health Effects Assessment for Toluene,
ECAO-CIN-HO-33, Environmental Criteria and Assessment Office, Cincinnati,
Ohio, September, 1984.
U.S. Environmental Protection Agency. Health Effects Assessment for 1.1.2. -
Trichloroethane. ECAO-CIN-HO-04, Environmental Criteria and Assessment
Office, Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Health Effects Assessment for
Trichloroethylene , ECAO-CIN-HO-46, Environmental Criteria and Assessment
Office, Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Health Effects Assessment for Trivalent
Chromium. ECAO-CIN-HO-35, Environmental Criteria and Assessment Office,
Cincinnati, Ohio, November, 1984.
U.S. Environmental Protection Agency, Slurry Trench Construction for Pollution
Migration. EPA/540-2-84-001, Washington, D.C., February, 1984.
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OSWER Directive 9481.00-1 1
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants, Volumes I and II, EPA/440-4-79-029a and b, Washington,
D.C., December, 1979.
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OSWER Directive 9481.00-11
APPENDIX A
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
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OSWER Directive 9481.00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
Criteria for Assessing Potential Adverse Effects on Ar. r e*.,,i»
Ground-Water Qualfty: *fL Case Study
§264.94(b)(1) Sectlon No-
(i) The physical and chemical characteristics of the 3.1,3.2
waste in the regulated-unit, including its
potential for migration;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3
facility ana surrounding land;
(iii) The quantity of ground water and the direction 5.3
of ground-water flow;
(iv) The proximity and withdrawal rates of ground- 4.2
water users;
(v) The current and future uses of ground water in 4.1,4.2
the area;
(vi) The existing quality of ground water, including 3.2
other sources of contamination and their
cumulative impact on the ground-water
quality;
(vii) The potential for health risks caused by human 6.1,6.3
exposure to waste constituents;
(viii) The potential damage to wildlife, crops, 6.2,6.3
vegetation, and physical structures caused by
exposure to waste constituents;
(ix) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects;
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OSWER Directive 9481.00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
(Continued)
Criteria for Assessing Potential Adverse Effects on Ar, r
Hydraulkally-Connected Surface-Water Quality: SSion 5n
§264.94(b)(2) . bection NO.
(i) The volume and physical and chemical 3.1,3.2
characteristics of the waste in the regulated
unit;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3,5.4
facility and surrounding land;
(iii) The quantity and quality of ground wat:--, and 5.3,5.4
the direction of ground-water flow;
(iv) The patterns of rainfall in the region; 4.3
(v) The proximity of the regulated unit to surface 4.2
waters;
(vi) The current and future uses of surface waters in 4.1,4.2
the area and any water quality standards
established for those surface waters;
(vii) The existing quality of surface water, including 3.2
other sources of contamination and the
cumulative impact on surface water quality;
(viii) The potential for health risks caused by human 6.1, 6.3
exposure to waste constituents;
(ix) The potential damage to wildlife, crops, 6.2, 6.3
vegetation, and physical structures caused by
exposure to waste constituents; and
(x) The persistence and permanence of the 3.1,3.2,8.1,6.2
potential adverse effects.
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OSWER Directive 9481 00-11
APPENDIX B
PHYSICAL AND CHEMICAL PROPERTIES OF
BENZENE, CHROMIUM, METHYLENE CHLORIDE
TOLUENE, 1,1,1-TRICHLOROETHANE.ANDTRICHLOROETHYLENE
AND
IRIS
(INTEGRATED RISK INFORMATION SYSTEM)
DATA BASE FOR
CHROMIUM, METHYLENE CHLORIDE,
TOLUENE, 1,1,1-TRICHLOROETHANE.ANDTRICHLOROETHYLENE
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OSWER Directive 9481 00-1
CHEMICAL AND PHYSICAL PROPERTIES OF
BENZENE
Summary
Benzene is an important industrial solvent and chemical intermediate. It is
rather volatile, and atmospherk photooxidation is probably an important fate
process. Benzene is a known human carcinogen, causing leukemia in exposed
individuals. It also adversely affects the hematopoietic system. Benzene has been
shown to be fetotoxic and to cause embryolethality in experimental animals.
Exposure to high concentrations of benzene in the air causes central nervous system
depression and cardiovascular effects, and dermal exposure may cause dermtitis.
CAS Numbers: 71-43-2
IDPACName: Benzene
Chemical Formula: Ce Hg
Chemical and Physical Properties
Molecular Weight: 78.12
Boiling Point: 80.1°C
Melting Point: 5.56°C
Specific Gravity: 0.879 at 20°C
Solubility in Water: 1,780 mg/liter at 25°C
Solubility in Organics: Miscible with ethanol, ether, acetic acid, acetone,
chloroform, carbon disulfide, and carbon tetrachloride
Henry's Law Constant: 5.5 x 10-3 atm -m3/mole at 25°C
Vapor Pressure: 75 mm Hg at 20°C
Vapor Density: 2.77
Viscosity: 0.693 centipoise at 16°C
FlashPoint: -11.1°C
Log Octanol/Water Partition Coefficient: 1.95-2.13
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OSWER Directive 9481.00-11
Transport and Fate
Volatilization appears to be the major transport process of benzene from
surface waters to the ambient air, and atmopsheirc transport of benzene occurs
readily (EPA, 1979). Although direct oxidation of benzene in environmental waters
is unlikely, cloud chamber data indicate that it may be photooxidized rapidly in the
atmosphere. In as much as volatilization is likely to be the main transport process
accounting from the removal of benzene from water, the atmospheric destruction
of benzene is probably the most likely fate process. Values for benzene's log
octanol/water partition coefficient indicate that adsorption onto organic material
may be significant under conditions of constant exposure. Sorption processes are
likely removal mechanisms in both surface water and groundwater. Although the
bioaccumulation potential for benzene appears to be low, gradual biodegradation
by a variety of microorganisms probably occurs. The rate of benzene
biodegradation may be enhanced by the presence of other hydrocarbons.
Health Effects
Benzene is a recognized human carcinogen (IARC, 1982). Several
epidemiological studies provide sufficient evidence of a causal relationship
between benzene exposure and leukemia in humans. Benzene is a known inducer
of aplastic anemia in humans, with a latent period of up to 10 years. It produces
leukopenia and thrombocytopenia, which may progress to pancyto-penia. Similar
adverse effects on the blood-cell-producing system occur in animals exposed in
benzene. In both humans and animals, benzene exposure is associated with
chromosomal damage, although it is not mutagenic in microorganisms. Benzene is
fetotoxic and causes empryolethality in experimental animals.
Exposure to very high concentrations of benzene [about 20,000 ppm (66,000
mg/m3) in air] can be fatal within minutes (IARC, 1982). The prominent signs are
central nervous system depression and convulsions, with death usually following as
a consequence of cardiovascular collapse. Milder exposures can produce vertigo,
drowsiness, headache, nausea, and eventually unconsciousness if exposure
continues. Deaths from cardiac sensitization and cardiac arrhythmias have also
been reported after exposure to unknown concentrations. Although most benzene
hazards are associated with inhalation exposure, dermal absorption of liquid
benzene may occur, and prolonged or repeated skin contact may produce
blistering, erythema, and a dry scaly dermatitis.
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OSWER Directive 9481 00-11
Toxicitv to Wildlife and Domestic Animals
The LCso values for benzene in a variety of invertebrate and vertebrate
freshwater aquatic species range from 5,300 ug/liter to 386,000 ug/liter (EPA, 1980).
However, only values for the rainbow trout (5,300 ug/liter) were obtained from a
flow through test and were based on measured concentrations. Results based on
unmeasured concentration in static tests are likely to underestimate toxicity for
relatively volatile compounds like benzene. A chronic test with Daphnia magna was
incomplete, with no adverse effects observed at test concentrations as high as
98,000 ug/liter.
For saltwater species, acute values for one fish and five invertebrate species
range from 10,900 ug/liter to 924,000 ug/liter. Freshwater and saltwater plant
species that have been studied exhibit toxic effects at benzene concentrations
ranging from 20,000 ug/liter to 525,000 ug/liter.
Standards and Criteria
National Primary Drinking Water Standard (U.S. EPA):
MCL: 50ug/l
Ambient Water Quality Criteria (U.S. EPA):
Aquatic Life
The available data are not adequate for establishing criteria. However, EPA
did report the lowest concentrations of benzene known to cause toxic effects
in aquatic organisms.
Freshwater
Acute toxicity: 5,300 ug/liter
Chronic toxicity: No available data
Saltwater
Acute toxicity: 5,100 ug/liter
Chronic toxicity: No available data
Human Health
Water and Aquatic Organisms Ingestion: 0.66 ug/l (10-6 Risk)
Aquatic Organisms Ingestion Only: 40 ug/l (10-6 Risk)
Other
(CAG Potency Factor: 3x10-2(mg/kg/day)-i
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OSWER Directive 9481.00-11
REFERENCES FOR BENZENE
EPA (U.S. Environmental Protection Agency), 1979. Water-Related Fate of 129
Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December.
EPA (U.S. Environmental Protection; Agency), 1980. Ambient Water Quality Criteria
for Benzene. EPA/440-5-80~ai8, Washington, D.C, October.
IARC (International Agency for Research on Cancer, 1982. "Some Industrial
Chemicals and Dyestuffs," IARC Monograph on the Evaluation of the
Carcinogenic Risk of Chemicals to Humans, Vol. 29, World Health
Organization, Lyon, France.
Other Resource Documents
American Conference of Governmental Industrial Hygienists, Documentation of the
Threshold Limit Values. 4th ed., Cincinnati, Ohio, 1980,488 pp.
Brief, R.S., J. Lynch, T. Bernath, and R.A. Scala, "Benzene in the Workplace", Am.
Ind. Hyq. Assoc. J. 41:616-623. 1980.
Dean, B.J., "Genetictoxicology of benzene, toluene, xylenes, and phenols", Mutat.
Res, 47:75-97, 1978.
Haak, H.L, "Experimental drug-induced aplastic anemia", Clin. Hematol. 9:621-639.
1980.
McCoy and Associates, "Physical/Chemical Data Compendium for Common
Solvents", The Hazardous Waste Consultant. Vol. 4, No. 6, Nov./Dec, 1986.
International Agency for Research on Cancer, "An evaluation of chemicals and
industrial processes associated with cancer in humans based on human and
animal data", IARC Monographs Volumes 1-20. Cancer Res. 40:1-12.1980.
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OSWER Directive 9481.00-11
International Agency for Research on Cancer, "Some Anti-Thyroid and Related
Substances, Nitrofurans, and Industrial Chemicals," IARC Monograph on the
Evaluation of the Carcinogenic Risk of Chemicals to Man, Vol. 7, World Health
Organization, Lyon, France, 1974.
U.S. Environmental Protection Ag'ency, Chemical. Physical and Biological Properties
of Compounds Present at Hazardous Waste Sites, Final Report, OWPE/OSWER,
Washington, D.C., September 27,1985.
U.S. Environmental Protection Agency, Health Assessment Document for
Chloroform. EPAy600-8-84-004F, Washington, D.C., September 1985.
U.S. Environmental Protection Agency, Health Effects Assessment for Benzene. Final
Draft, ECAO-CIN-HO-37, Environmental Criteria and Assessment Office,
Cincinnati, Ohio, September 1984.
Waldron, H.A., "Target organs: The blood." J. Soc. Ocup. Med. 29:65-71.1979.
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OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERITES OF
CHROMIUM
Summary
CAS Number: 7440-4/-3
Chemical Formula: Cr
IDPACName: Chromium
Chemical and Physical Properties (Metal)
Atomic Weight: 51.996
Boiling Point: 2672°C
Melting Point: 1857 _±_ 20°C
Specific Gravity: 7.20 at 28°C
Solubility in Water: Insoluble; some compounds are soluble
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Chromium(V1); CAS No. 7440-47-3 (Revised 09/30/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment inforrnatipn on chemicals is included in IRIS only after a
comprehensive review of chronic toxicity data by work groups composed of U.S.
EPA scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive US. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Chromium(VI)
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Regulatory Actions: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
8-8
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OSWER Directive 9481.00-1!
assessment information pertaining to the carcinogenicity of this compound. Please
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE {RfD) FOR ORAL EXPOSURE
Chemical: Chromium(VI), soluble salts
CAS No.: 7440-47-3 " Preparation Date: 12/15/86
___„___._._..._..—..——----.--.-.---- -*-,-.„..„.__.___.._--..-..-—.....—....—.. . .—.—„
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
No effects reported NOAEL: 25 mg/Lof 500 1 5E-3
chromium as K2CrO4 mg/kg/day
Rat, 1-Year Drinking (converted to 2.4 mg
Study of chromium(VI)/kg/day)
MacKenzie et al., LOAEL: none
1958
* Dose Conversion Factors & Assumptions: Drinking water consumption =
0.097 L/kg/day (reported)
2. PRINCIPAL AND SUPPORTING STUDIES
MacKenzie, R.D., R.U. Byerrum, CF. Decker, CA. Hoppert and R.F. Langham.1958.
Chronic toxicity studies. II. Hexavalent and trivalent chromium administered in
drinking water to rats. Am. Med. Assoc. Arch. Ind. Health. 18: 232-234.
Groups of eight male and eight female Sprague-Dawley rats were supplied
with drinking water containing 0-11 ppm (0-11 mg/L) hexavalent chromium (as
K2OO4) for 1 year. The control group (10/sex) received distilled water. A second
experiment involved three groups of 12 males and 9 female rats. One group was
given 25 ppm (25 mg/L) chromium (as K2OO4); a second received 25 ppm chromium
in the form of chromic chloride; and the controls again received distilled water. No
significant adverse effects were seen on appearance, weight gain, or food
consumption, and there were no pathologic changes in the blood or other tissues in
any treatment group. The rats receiving 25 ppm of chromium (as K2CrO4) showed
an approximate 20% reduction in water consumption. This dose corresponds to 2.4
mg chromium(VI)/kg/day based on actual body weight and water consumption
data.
For rats treated with 0-11 ppm (in the diet), blood was examined monthly, and
tissues (livers, kidneys and femurs) were examined at 6 months and 1 year. Spleens
were also examined at 1 year. The 25 ppm groups (and corresponding controls)
were examined similarly, except that no animals were killed at 6 months. An abrupt
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OSWER Directive 9481.00-11
rise in tissue chromium concentrations was noted in rats treated with greater than 5
ppm. The authors stated that "apparently, tissues can accumulate considerable
quantities of chromium before pathological changes result." In the 25 ppm
treatment groups, tissue concentrations of chromium were approximately 9 times
higher for those treated with hexavalent chromium than for the trivalent group.
Similar no-effect levels have been observed in dogs and humans. Anwar et al.
(1961) observed no significant effects in female dogs (2/dose group) given up to 11 2
ppm chromium(VI) (as K2CrO4) in drinking water for 4 years. The calculated doses
were 0.012-0.30 mg/kg of chrormcim(VI). In humans, no adverse health effects were
detected (by physical examination) in a family of four persons who drank for 3 years
from a private well containing Cr VI at approximately 1 mg/L (0.03 mg/kg/day for a
70-kg human).
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 500. The uncertainty factor of 500 represents two 10-fold decreases in dose to
account for both the expected interhuman and interspecies variability in the toxicity
of the chemical in lieu of specific data, and an additional factor of 5 to compensate
for the less-than-lifetime exposure duration of the principal study.
MF = 1
4. ADDITIONAL COMMENTS
ThisRfD is limited to metallic chromium(VI) of soluble salts. Examples of
soluble salts include potassium dichromate (K2CR2O7), sodium dichromate
(Na2Cr2O7), potassium chromate (K2CrO4) and sodium chromate (Na2CrO4).
Trivalent chromium is an essential nutrient. There is some evidence to indicate
that hexavalent chromium is reduced in part to trivalent chromium in vivo (Petrilli
and DeFlora, 1977,1978; Gruberand Jennette, 1978).
The literature available on possible fetal damage caused by chromium
compounds is limited. No studies were located on teratogenic effects resulting
from ingestion of chromium.
5. CONFIDENCE IN THE RfD
Study: Low DataBase: Low RfD: Low
Confidence in the chosen study is low because of the small number of animals
tested, the small number of parameters measured and the lack of toxic effect at the
highest dose tested. Confidence in the data base is low because the supporting
studies are of equal reduced quality, and teratogenic and reproductive endpoints
are not well studied. Low confidence in the RfD follows.
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OSWER Directive 9481.00-1
6. DOCUMENTATION AND REVIEW
U.S. EPA 1984. Health and Effects Assessment for Hexavalent Chromium. Prepared
by the Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Cincinnati, OH for the Office of Soild Waste and Emergency
Response, Washington, DC.
U.S. EPA. 1985. Drinking Water Health Advisory for Chromium. Prepared by the
Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Cincinnati, OH.for the Office of Drinking Water, Washington,
DC. (Draft)
Agency RfD Work Group Review: 11/21/85,02/05/86
Verification Date: 02/05/86
7. U.S. EPA CONTACTS
Primary: K.L Bailey FTS/382-5535 or 202/382-5535
Office of Drinking Water
Secondary: C.T. DeRosa FTS/684-7534 or 513/569-7534
B. REFERENCE DOSE (RFD) FOR INHALATION EXPOSURE
Chemical: Chromium (VI)
CAS No.: 7440-47-3
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: ChromiumVI
CAS No.: 7440-47-3 Preparation Date: 10/01/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification: A, human carcinogen by the inhalation route. Results of
epidemiologic studies are consistent across investigators and locations. Dose-
response relationships for lung tumors have been established.
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OSWER Directive 9481.00-11
1. HUMAN DATA
Sufficient. Epidemiologic studies of chromate production facilities in the
United States (Machle and Gregorius, 1948; Brinton et al., 1952; Mancusco
andHueper, 1951, Mancuso, 1975; Baetjer, 1950; Taylor, 1966; Enterline, 1974;
Hayes etal., 1979; Hill and Ferguson, 1979), Great Britain (Bidstrup, 1951; Bidstrup
and Case, 1956; Alderson et al., 1981), Japan (Watanabe and Fukuchi, 1975; Ohsaki
etal., 1978; Sanoand Mitohara, 1978; Satohetal., 1981) and West Germany
(Korallusetal., 1982; Bittersohlt.1971) have established an association for chromium
exposure and lung cancer. Mostof these studies did not attempt to determine
whether Cr III or Cr VI compounds were the etiologic agents.
Three studies of the chrome pigment industry, one in Norway (Langard and
Norseth, 1975), one in England (Davies, 1978, 1979), and the third in the
Netherlands and Germany (Frentzel-Beyme, 1983) also found an association
between occupational chromium exposure (predominantly to Cr VI) and lung
cancer.
Results of two studies of the chromium plating industry (Royle, 1975;
Silverstein etal., 1981) were inconclusive, while the findings of a Japanese study of
chrome platers were negative (Okubo and Tsuchiya, 1979).the results of studies of
ferrochromium workers (Pokrovskaya and Shabynina, 1973; Langard et al., 1980;
Axelsson et al., 1980) were inconclusive as to lung cancer risk.
2. ANIMAL DATA
Sufficient. Hexavalent chromium compounds were carcinogenic in animal
assays producing the following tumor types: intramuscular injection site tumors in
Fischer 344 and Bethesda Black rats and in C57BL mice (Furst etal., 1976; Maltoni,
1974,1976; Payne, 1960; Heuperand Payne, 1959); intra-plural implant site tumors
for various chromium VI compounds in Sprague-Dawley and Bethesda Black rats
(Payne, 1960; Heuper 1961; Heuperand Payne, 1962); intrabronchial implantation
site tumors for various Cr VI compoundsin Wistar rats (Levy and Martin, 1983; Laskin
et al., 1970; Levy as quoted in NIOSH, 1975); and subcutaneous injection site
sarcomas in Sprague-Dawley rats (Maltoni, 1974,1976).
3. SUPPORTING DATA
A large number of chromium compounds have been assayed in in vitro genetic
toxicology assays. In general, hexavalent Cr is mutagenic in bacterial assays whereas
trivalentCrisnot(Lofroth, 1978; Petrellieand Flora, 1977,1978). Likewise Cr VI but
not Cr III was mutagenic in yeasts (Bonatti et al., 1976) and in V79 cells (Newbold et
al., 1979). Chromium III and VI compounds decrease the fidelity of DNA synthesis in
vitro (Loeb et al., 1977), while Cr VI compounds inhibit replicative DNA synthesis in
mammalian cells (Levis et al., 1978) and produces unscheduled DNA synthesis,
presumably repair synthesis as a consequence of DNA damage (Raffetto, 1977).
Chromate nas been shown to transform both primary cells and cell lines (Fradkin et
al., 1975; Tsuda and Kato, 1977; Castoetal., 1979). Chromosomal effects produced
by treatment with chromium compounds have been reported by a number of
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authors; for example, both Cr VI and Cr III salts were clastogenic for cultured human
leukocytes (Nakamuro etal., 1978).
B. ORAL QUANTITATIVE ESTIMATE
Not available.
There are no studies indicatingthat Cr VI is carcinogenic by oral administration.
Because there appears to be significant in vivo conversion of Cr VI to Cr III and III to
VI, exposure to one form of Cr involves exposure to all forms of Cr. Cr III is an
essential trace element.
C. INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 4.1 E + 1/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
8E-3 8E-4 8E-5 1.2E-2 MuJtistage
ug/cu.m ug/cu.m ug/cu.m (extra risk)
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Incidence
Route: Occupational exposure
(inhalation)
Age
(years)
50
60
70
Midrange
(ug/cu.m)
5.66
25.27
46.83
4.68
20.79
39.08
4.41
21.29
Deaths from
Lung Cancer
3
6
6
4
5
5
2
4
Person
Years
1345
931
299
1063
712
211
401
345
Mancuso,
1975
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OSWER Directive 9481.00-11
3. ADDITIONAL COMMENTS
The cancer mortality in Mancuso (1975) was assumed to be due to Cr VI, which
was further assumed to be no less than one-seventh of total Cr. It was also assumed
that the smoking habits of chromate workers were similar to those of the U.S. white
male population. Slope factors based on Langard etal. (1980), Axelsson etal.
(1980), and Pokrovskaya and Shabynina (1973) result in air unit risk estimates of
1.3E-1, 3.5E-2 and 9.2E-2 ug/cu.m,/espectively.
Hexavalent chromium compounds have not produced lung tumors in animals
by inhalation. Trivalent chromium compounds have not been reported as
carcinogenic by any route of administration.
The unit risk should not be used if the air concentration exceeds 8E-1 ug/cu.m,
since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
Results of studies of chromium exposure are consistent across investigators
and countries. A dose-relationship for lung tumors has been established. The :
assumption that the ratio of Cr III to Cr VI is 6:1 may lead to a 7-fold
underestimation of risk. The use of 1949 hygiene data, which may underestimate
worker exposure, may result in an overestimation of risk. Further overestimation of
risk may be due to the implicit assumption that the smoking habits of chromate
workers were similar to those of the general while male population, as it is
generally accepted that the proportion of smokers is higher for industrial workers
than for the general population. Confidence is rated medium.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
D. DOCUMENTATION AND REVIEW
1. REFERENCES
Mancuso, T.F. 1975. International Conference on Heavy Metals in the Environment.
Toronto, Ontario, Canada.
U.S. EPA. 1984. Health Assessment Document for Chromium. Prepared by the
Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Cincinnati, OH. EPA 600/8-83-014F.
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REVIEW
The quantification of cancer risk in the 1984 Health Assessment document has
received peer review in-public sessions of the Environmental Health Committee of
the U.S. EPA's Science Advisory Board.
Agency Work Group Review: 06/26/86
Verification Date: 06/26/86
3. U.S. EPA CONTACTS
Primary: C.W.Chen 202/382-5719 or FTS, 182-5719
Office of Research and Development
Secondary: H.J.Gibb 202/382-5898 or FTS/382-5898
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Chromium(VI)
CAS No.: 7440-47-3
Information is not available at this time.
IV. REGULATORY ACTIONS
Chemical: Chromium(VI)
CAS No.: 7440-47-3 Preparation Date: 09/30/87
INTERPRETATION OF REGULATORY ACTION INFORMATION
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Regulatory actions are frequently not
updated at the same time. Carefully read the dates for the regulatory actions (in
this section) and the verification dates for the risk assessments (in sections I & II), as
this may explain apparent inconsistencies. Also note that some regulatory actions
consider factors not related to health risk, such as technical or economic feasibility.
Such considerations are indicated for each action following (Econ/Tech Feasibility
entry). In addition, not all of the regulatory actions listed in this section involve
enforceable federal standards. Please direct any questions you may have
concerning the use of risk assessment information in making a regulatory decision
to the U.S. EPA contact listed for that particular regulatory action. Users are
strongly urged to read the background information on each regulatory action in
Appendix D in Service Code 4.
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A. AIR
CLEAN AIR ACT, Section 112
Action (status)-- Intenttolist (Current, 1985)
Considers technological or economic feasibility? -- NO
Discussion -- Chromium VI is considered a human carcinogen (IARC Group I), and
according to EPA's preliminary risk assessment from ambient air exposures, public
health rislcs are significant. There is considerable uncertainty as to the
carcinogenicity of other valence states of chromium and the proportion of
chromium VI in emission or ambient air samples. The EPA indicated that it intends
to add total chromium or chromium VI to the list of hazardous air pollutants for
which it intends to establish emission standards under section 112(b)(1 )(A) of the
Clean Air Act. The EPA will decide whether to add total chromium or chromium VI
to the list only after studying possible techniques that might be used to control
emissions and further assessing the public health risks. The EPA will add total
chromium or chromium VI to the list if emission standards are warranted.
Reference-- 50 FR 24317 (06/10/85)
U.S. EPA Contact -- Office of Air Quality Planning and Standards
919/541-5645 or FTS/629-5645
B. WATER
MAXIMUM CONTAMINANT LEVEL GOAL (MCLG); for Drinking Water
Value (status) -- 0 mg/L (Proposed, 1985)
Considers technological or economic feasibility? -- NO
Discussion -- An MCLG of 0.12 mg/L for total chromium (Cr III and CrVI) is proposed
based on a provisional DWELof 0.17 mg/L with data on human exposure factored in
(0.10mg/day inthedietand 0 mg/day by air). A DWELof 0.17 mg/L was calculated
fromaNOAELof 2.41 mg/kg/day in rats [1-year drinking water study (CrVI)], with
an uncertainty factor of 500 applied and consumption of 2 L of water/day assumed.
Reference -- 50 FR 46936 Part IV (11/13/85)
U.S. EPA Contact -- Office of Drinking Water
202/382-5543 or FTS/382-5543
C. TOXICS/PESTICIDES
Information is not available at this time.
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D. SUPERFUND
Information is not available at this time.
V. SUPPLEMENTARY DATA
Chemical: Chromium(VI)
CAS No.: 7440-47-3
Information is not available at this time.
SYNONYMS: CHROMIUM; CHROME; CHROMIUM (ACGIH)
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Chromium (III); CAS No. 16065-83-1 (Revised 11/16/1986)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic toxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Chromium (III)
I. Chronic Systemic Toxicity: Noncarcinogenic Health Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: none
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Chromium (III), Insoluble Salts
CASNo.: 16065-83-1 v Preparation Date: 05/13/86
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Rat chronic feeding NOEL: 5% Cr2O3 in 100 10 1
study diet 5 days/week for mg/kg/day
600 feed ings (1800 (as an
a/kg bw average total insoluble
dose) salt)
Ivankovicand
Preussmann(1975) LOAEL: None
* Dose Conversion Factors & Assumptions: 1800 g Cr2O3/kg bw x 1000 mg/g x
0.6849 Cr/g Cr2O3 / 600 feeding days x 5 feeding days/7 days = 1468
mg/kg/day
2. PRINCIPAL AND SUPPORTING STUDIES
Ivankovic, S. and R. Preussmann. 1975. Absence of toxic and carcinogenic effects
after administration of high doses of chromic oxide pigment in subacute and long-
term feeding experiments in rats. Food Cosmet. Toxicol. 13:
347-351.
Groups of 60 male and female rats were fed chromic oxide (Cr2O3) baked in
bread at dietary levels of 0,1, 2 or 5%, 5 days/week for 600 feedings (840 total days).
The primary purpose of this study was to assess the carcinogenic potential of Cr2O3.
Body weight and food consumption were monitored. The average total amounts of
ingested Cr2O3 were given as 360, 720 and 1800g/kg bw for the 1, 2 and 5%
treatment groups, respectively. The animals were maintained on control diets
following termination of exposure until they became moribund or died. All major
organs were examined histologically. Other toxicological parameters were not
mentioned explicitly, but may have included some or all of those described for the
accompanying subchronic study (see below). No effects due to Cr2O3 treatment
were observed at any dose level.
Ivankovicand Preussmann (1975) also treated rats (both sexes, 12-19
rats/group) at dietary levels of 0, 2 or 5% Cr2O3 in bread, 5 days/week for 90 days.
Food consumption and body weight were monitored. Toxicological parameters
included serum protein, bilirubin, hematology, urinalysis, organ weights and
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OSWER Directive 9481.00-11
histopathology. The only effects observed were reductions (12-37%) in the absolute
weights of the livers and spleens of animals in the high-dose group. Organ weights
relative to body weight were not reported. The high dose is equivalent to 1400
mg/kg/day (dose converted using reported data).
Other subchronic oral studies show no indication of adverse effects
attributable to trivalent chromium compounds, but dose levels were considerably
lower.
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 100. The factor of 100 represents two 10-fold decreases in mg/kg bw/day dose
that account for both the expected interhuman and interspecies variability to the
toxicity of the chemical in lieu of specific data.
MF * 10. The additional modifying factor of 10 is adopted to reflect uncertainty
around the NOEL because: 1) the effects observed in the 90-day study were not
explicitly addressed in the 2-year study and, thus, the highest NOAEL in the 2-year
study may be a LOAEL; 2) the absorption of chromium is so low(<1%) and is
influenced by a number of factors; thus, a considerable potential variation in
absorption exists; and 3) animals were allowed to die naturally after feeding
stopped (2 years) and only then was histology performed.
4. ADDITIONAL COMMENTS
This RfD is limited to metallic chromium (III) of insoluble salts.
Examples of insoluble salts include chromic III oxide (O203), chromium III chloride
(CrC13) and chromium III sulfate [Cr2(SO4)3].
Very limited data suggest that Cr III may have respiratory effects on humans.
No data on chronic or subchronic effects of inhaled Cr III in animals can be found.
Adequate teratology data do not exist, but reproductive effects are not seen at
dietary levels of 5% Cr2O3.
5. CONFIDENCE IN THE RfD
Study: Low DataBase: Low RfD: Low
The critical study is rated low because of the lack of explicit detail of study
protocol and results. Low confidence in the data base reflects the lack of high-dose
supporting data. The low confidence in the RfD reflects the foregoing, but also
reflects the lack of an observed effect level. Thus, the RfD, as given, should be
considered conservative, since the MF addresses only those factors which might
lower the RfD.
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OSWER Di recti ve 9481.00-11
6. DOCUMENTATION AND REVIEW
U.S. EPA. 1984. Health Effects Assessment for Trivalent Chromium. Prepared by the
Environmental Criteria and Assessment Office, Cincinnati, OH, OHEA for the Office
of Solid Waste and Emergency Response. ECAO-CIN-HO'35.
The ADI in the 1984 Health Effects Assessment document received an Agency review
with the help of two external scientists.
Agency RfD Work Group Review: '11/21/85, 02/05/86
Verification Date: 11/21/85
7. U.S. EPA CONTACTS
Primary: M.L Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
Secondary: C.T. DeRosa FTS/684-7 534 or 513/569-7534
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Chromium (III)
CAS No.: 16065-83-1
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Chromium (III)
CAS No.: 16065-83-1
This chemical has not been evaluated by the U.S. EPA for evidence of human
carcinogenic potential.
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Chromium (III)
CAS No.: 16065-83-1
Information is not available at this time.
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OS WE R Directive 9461 00-11
IV. RISK MANAGEMENT SUMMARIES
Chemical: Chromium (III), Insoluble Salts
CAS No.: 16065-83-1 Preparation Date: 09/30/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
A. RISK MANAGEMENT ACTIONS
Risk.
Management
Action
Reportable
Quantity (RQ)
Status
Date
Final
1985
Risk
Management
Value
none
Considers
Econ/Tech
Feasibility
no
Reference
50 FR 13456
04/04/85
Water Quality
Criteria (WQC):
a. Human Health
b. Aquatic Toxicity
1) Freshwater
2) Marine
Final
1980
Final
1980
170mg/l no
Acute no
various
Chronic
various
none
45 FR 793 18
1 1/28/80
ibid.
B. RISK MANAGEMENT RATIONALE
RQ
Though "Chromium (III), insoluble salts" is not specifically designated as a
CERCLA hazardous substance, insoluble chromium (III) salts would be considered
hazardous substances under the CERCLA broad generic listing for "CHROMIUM AND
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OSWER Directive 9481.00-11
COMPOUNDS." There is no corresponding reportable quantity (RQ) for this generic
class of compounds, but the releaser is still liable for cleanup costs if the designated
federal, On-Scene Coordinator (OSC) decides to take response action with respect to
the release of an insoluble chromium (III) salt which is not otherwise specifically
listed as a CERCLA hazardous substance. There are two chromium (III) salts which
are specifically listed as CERCLA hazardous substances, chromic acetate and chromic
sulfate. Both have been assigned final RQsof 1000 pounds based on aquatic toxicity
(as established under section 311 (b}(4) of the Clean Water Act).
Contact: Office of Emergency and Remedial Response
202/382-2180 or FTS/382-2180
WQC
Contact: Office of Water Regulations and Standards
202-382-5400 or FTS-382-5400
a. Human health: The WQC of 170 mg/l is based on consumption of
contaminated aquatic organisms and water. A WQC of 3433 mg/l has also been
established based on consumption of contaminated aquatic organisms alone.
b. Aquatic toxicity: Water quality criteria for the protection of aquatic life are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The data are assumed to be statistically representative and are used to
calculate concentrations which will not have significant short or long term effects
on 95% of the organisms exposed. Recent criteria (1985 and later) contain duration
and frequency stipulations: the acute criteria maximum concentration is a 1 -hour
average and the chronic criteria continuous concentration is a 4-day average which
are not to be exceeded more than once every three years, on the average (see
Stephen etal. 1985). Earlier criteria (1980-1984) contained instantaneous acute and
24-hour average chronic concentrations which were not to be exceeded. (FR 45:
79318: November 28,1980). These criteria vary with water hardness. For
freshwater aquatic life the concentration (in ug/l) of total recoverable trivalent
chromium should not exceed the numerical value given by the equations
"e**(0.8190 [In (hardness)J + 3.688)" for acute exposure and "e**(0.8190 [In
(hardness)] + 1.561)" for chronic exposure (** indicates exponentiation; hardness is
in mg/l). For example, at a hardness of 50 mg/l, the acute and chronic WQC would
be 980 and 120 ug/l respectively.
V. SUPPLEMENTARY DATA
Chemical: Chromium (III)
CAS No.: 16065-83-1
Information is not available at this time.
Synonyms: CHROMIUM, ION (Cr 3 +); CHROMIC ION; CHROMIUM (3 +);
CHROMIUM (III); CHROMIUM (III) ION; CHROMIUM ION (3 + )
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OSWER Directive 9481.00-11
RESOURCE DOCUMENTS FOR CHROMIUM
American Conference of Governmental Industrial Hygienists, Documentation of the
Threshold Limit Values. 4th ed., Cincinnati, Ohio, 1980,488 pp.
International Agency for Research on Cancer, "Some Metals and Metallic
Compounds," IARC Monograph on the Evaluation of the Carcinogenic Risk of
Chemicals to Humans. Vol. 23, World Health Organization, Lyon, France, 1980.
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OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
METHYLENE CHLORIDE
Summary
CAS Number: 75-09-2/
Chemical Formula: CH2C12
lUPACName: Dichloromethane
Important Synonyms and Trade Names: Methylene dichloride, methane
dichloride
Chemical and Physical Properties
Molecular Weight: 84.93
Boiling Point: 40°C
Melting Point: -95,1°C
Specific Gravity: 1.3266 at 20°C
Solubility in Water: 13,200-20,000 mg/liter at 25°C
Solubility in Organics: Miscible with alcohol and ether
Henry's Law Constant: 3.19x 10-3atm-m3/moleat25°C
Vapor Pressure: 362.4 mm Hg at 20°C
Vapor Density: 2.93
Viscosity: 0.470 centipoise at 16°C
Flash Point: Not Flammable
Log Octanol/Water Partition Coeffecient: 1.25
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Methylene Chloride (Dichloromethane); CAS No. 75-09-2 (Revised 05/21/1987)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic toxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4. .
STATUS OF DATA FOR Methylene Chloride
I. Chronic Systemic Toxicity: Noncarcinogenic Health Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed fora lifetime. RfDscan also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSW E R Oi recti ve 9481.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Methylene Chloride
CAS No.: 75-09-2 Preparation Date: 06/13/86
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Livertoxicity NOAEL: 5.85 and 6.47 100 1 6E-2
mg/kg/day for males mg/kg/day
2-year rat drinking and females,
water bioassay respectively
National Coffee LOAEL: 52.58 and
Association (1982) 58.32 mg/kg/day for
males and females,
respectively
* Dose Conversion Factors & Assumptions: none
2. PRINCIPAL AND SUPPORTING STUDIES
National Coffee Association. 24-Month chronic toxicity and oncogenicity study of
methylene chloride in rats. Final Report. Prepared by Hazleton Laboratories
America, Inc., Vienna, VA, August 11,1982.
The chosen study appears to have been very well conducted, with 85 rats/sex at
each of four dose groups. A high-dose recovery group of 25 rats/sex, as well as two
control groups of 85 and 50 rats/sex, was also tested. Many effects were monitored.
The supporting data base is limited. A NOAEL of 87 mg/cu. m was reported in
one inhalation study (Haun et al., 1972). [The equivalent oral dose isabout 28 mg/kg
bw/day (i.e., 87 mg/cu. m x 0.5 x 0.223 cu. m/day/0.35 kg; these exposure values are
for rats).]
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 100. ;0ax10h) The 100-fold factor accounts for both the expected intra- and
interspecies variability to the toxicity of this chemical in lieu of specific data.
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MF = 1
4. ADDITIONAL COMMENTS
None.
5. CONFIDENCE IN THE RfD
Study: High DataBase: Medium RfD: Medium
The study is given a high confidence rating because a large number of animals of
both sexes were tested in four dose groups, with a large number of controls. Many
effects were monitored and a dose-related increase in severity was observed. The
data base is rated medium to low because only a few studies support the NOAEL
Medium confidence in the RfD follows.
6. DOCUMENTATION AND REVIEW
U.S. EPA. Drinking Water Criteria Document for Methylene Chloride. Office of
Drinking Water, Washington, DC. (1985)(Draft)
The ADI has been reviewed by the U.S. EPA's ADI (RfD) Work Group.
Agency RfD Work Group Review: 06/24/85,07/08/85,11/06/85
Verification Date: 11/06/85
7. U.S. EPA CONTACTS
Primary: K. Khanna FTS/382-7588 or 202/382-7588
Office of Drinking Water
Secondary: M.L. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Methylene Chloride
CAS No.: 75-09-2
Information is not available at this time.
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II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Methylene Chloride (dichloromethane)
CASNo.: 75-09-2 Preparation Date: 05/21/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification: B2, probable human carcinogen; based on inadequate data in
humans and increased cancer incidence in rats and mice.
1. HUM AN DATA
Inadequate. Neither of two studies of chemical factory workers showed an
excess of cancers (Friedlander et al., 1978,1985; Ott et al., 1983). In the former
study, exposures were low, but the data provide some suggestion of an increased
incidence of pancreatic tumors. The latter report was designed to examine
cardiovascular effects, and the study period was too short to allow for latency of
site-specific cancers.
2. ANIMAL DATA
Sufficient. In a 2-year study (National Coffee Association, 1982,1983) F344 rats
received 0, 5, 50,125 or 250 mg dichloromethane/kg/day in drinking water. B6C3FI
mice consumed 0, 60,125,185 or 250 mg/kg/day in water. Female rats responded
with increased incidence of neoplastic nodules or hepatocellular carcinomas, which
was significant by comparison to matched but not to historical controls. Male rats
did not show an increased incidence of liver tumors. Male mice had elevated
incidences of combined neo-plastic nodules and hepatocellular carcinomas, but
female mice did not. This increase was not statistically significant or do$e-r'elated.
An NTP (1982) gavage study of rats and mice has not been published because of
data discrepancies.
Inhalation exposure of male and female Syrian hamsters to 0, 500,1500 or
3500 ppm dichloromethane for 6 hours/day, 5 days/week for 2 years did not produce
neoplasia. Female Sprague-Dawley rats exposed under the same conditions
experienced reduced survival at the highest dose. Increased incidences of mammary
tumors were noted in both males and females. Male rats also developed salivary
gland sarcomas (Burek et al., 1984). There is a question as to whether these doses
were at or near the MTD. In a subsequent study (Burek et al., 1984) male and female
rats were exposed to 0, 50, 200 or 500 ppm dichloromethane. No salivary tumors
were observed, but the highest dose resulted in mammary tumors.
Groups of 50 each male and female F344/N rats and B6C3FI mice were exposed
to dichloromethane 6 hours/day, 5 days/week for 2 years. Exposure concentrations
were 0,1000, 2000 or 4000 ppm for rats and 0, 2000 or 4000 ppm for mice. Survival
of male rats was low, but apparently not treatment related; survival was decreased
in a treatment-related fashion for male and female mice and female rats.
Mammary adenomas and fibroadenomas were increased in male and female rats as
were mononuclear cell leukemias in female rats. Among treated mice of both sexes
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OSWER Directive 9481.00-11
Mouse/B6C3F1, Route: Water National
male; hepato- Coffee
cellular car- mg/kg/day mg/kg/day Association,
cinomasor 1983
adenomas 0
60
125
185
250
0
4.5
9.4
14.0
7 18.9
24/125
30/100
31/99
35/125
51/200
3. ADDITIONAL COMMENTS
Dichloromethane is rapidly absorbed following either inhalation or ingestion.
Use of inhalation data for calculation of risk is justified if lung tumor data are
excluded. The slope factor is an arithmetic mean of slope factors derived from NTP
(1986) and the National Coffee Association (1983) data (2.6E-3 and 1.2E-2,
respectively). Dose conversions used the mouse assay midpoint weight of 0.032 kg
and estimated inhalation rate of 1.0407 cu.m/day. To obtain estimates of unit risk
for humans, an inhalation rate of 20 cu.m/day was assumed. Dichloromethane was
considered to be a well absorbed vapor at low doses. At the time of publication ot
U.S. EPA (1985), no pharmacokinetic or metabolism data were available to justify
modification of the dose assumptions used in the calculation of carcinogenic risk.
The unit risk should not be used if the water concentration exceeds 5E + 4 ug/L,
since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE ESTIMATE
Adequate numbers of animals were used in both assays. Incidences of tumors
in the NTP (1986) bioassay were significantly increased in a dose-related fashion.
Incidences in the National Coffee Association (1983) study were elevated by
comparison to controls (p<0.05 for the 125,185 and 250 mg/kg/day groups). Risk
estimates based on the more sensitive sex in each study were within a factor of 5.
Confidence is rated medium to high.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of tne Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
C. INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 1.4E-2/mg/kg/day
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OSWER Oirective 9481.00-11
there were increased incidences of hepatocellular adenomas and carcinomas and
highly significant increases in alveolar/bronchiolar adenomas and carcinomas (NTP,
1986).
Two inhalation assays using dogs, rabbits, guinea pigs and rats were negative,
but were not carried out for thelifetime of the animals (Heppel etal., 1944;
MacEwen etal., 1972). Theissetal. (1977) injected strain A male mice
intraperitoneally with 0,160,400 Qr 800 mg/kg for 16-17 times. Pulmonary
adenomas were found, but survival of animals was poor.
3. SUPPORTING DATA
Dichloromethane is mutagenic for Salmonella typhimurium with or without
added hepatic enzymes (Green, 1983) and produced mitotic recombination in yeast
(Callen et al., 1980). Results in cultured mammalian cells have generally been
negative, but dichloromethane has been shown to transform rat embryo cells and
to enhance viral transformation of Syrian hamster embryo cells (Price et al., 1978;
Hatch etal., 1983).
B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 7.5 E-3/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/L)
5E + 2 ug/L 5E + 1 ug/L 5 ug/L 2.1E-7 LM, extra
risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Mouse/B6C3F1,
female; hepato-
cellular
adenomas or
carcinomas
Route: Inhalation
ppm mg/kg/day
0 0
2000 1582
4000 3162
NTP, 1986
mg/kg/day
0
122
244
3/50
16/48
40/48
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OSWER Directive 9481.QO-11
1. UNIT RISK SUMMARYTABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
2E + 1 2 2E-1 4.1 E-6 LM, extra
ug/cu.m ug/cu.m irg/cu.m risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Mouse/B6C3F1, Route: Inhalation NTP, 1986
female; combined
carcinomas and ppm mg/kg/day mg/kg/day
adenomas of the
lung or liver 00 0 5/50
2000 5.82 122 36/48
4000 31.64 244 46/47
3. ADDITIONAL COMMENTS
Dose conversions used the mouse assay midpoint weight of 0.032 kg and
estimated inhalation rate of 1.04 cu.m/day. To obtain estimates of unit risk for
humans, an inhalation rate of 20 cu.m/day was assumed. Dichloromethane was
considered to be a well absorbed vapor at low doses. There are currently no
pharmacokinetic or metabolism data to justify modification of dose assumption
used in the calculation of carcinogenic risk.
The unit risk should not be used if the air concentration exceeds 2E + 3
ug/cu.m, since above this concentration the slope factor may differ from
that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
Adequate numbers of animals were observed and tumor incidences were
significantly increased in a dose-dependent fashion. Analysis excluding animals
which died before observation of the first tumors produced similar risk estimates as
did time-to-tumor analysis. Risk estimates for both sexes of mice (NTP, 1986) were
within a factor of 2, as the slope factor for male mice was 7.0E-3. Confidence is
rated medium to high.
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Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
D. DOCUMENTATION AND REVIEW
1. REFERENCES
U.S. EPA. 1985. Addendum to the Health Assessment Document for
Dichloromethane (methylene chloride). Updated carcinogenicity assessment.
Prepared by the Carcinogen Assessment Group, OHLA, Washington, DC. EPA
600/8-B2/004FF.
NTP (National Toxicology Program). 1986. Toxicology and carcinogenesis studies of
dichloromethane (methylene chloride) in F344/N rats.and B6C3FI mice (inhalation
studies). NTP-TRS-306.
National Coffee Association. (1983). Twenty-four month oncogenicity study of
methylene chloride in mice. Prepared by Hazelton Laboratories, America Inc.,
Vienna, VA. Unpublished.
2. REVIEW
The Addendum to the Health Assessment Document for Dichloromethane
(methylene chloride) received Agency and external review including a review by the
Science Advisory Board.
Agency Work Group Review: 12/04/86
Verification Date: 12/04/86
3. U.S. EPA CONTACTS
Primary: H. Spitzer 202/382-7669 or FTS/382-7669
Office of Research and Development
Secondary: D.Singh 202/382-5898 or FTS/382-5898
Office of Research and Development
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Methylene Chloride
CAS No.: 75-09-2
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Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical:
CAS No.:
Methylene Chloride
75-09-2
Preparation Date: 10/16/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in Sections I & II), as this may explain apparent inconsistencies. Also
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
A. RISK MANAGEMENT ACTIONS
Risk
Management
Action
Reportable
Quantity (RQ)
Status
Date
Final
1985
Risk
Management
Value
IOOO Ibs.
Considers
Econ/Tech
Feasibility
no
Reference
50 FR 13456
04/04/85
Water Quality
Criteria (WQC):
a. Human Health
b. Aquatic Toxicity
1) Freshwater
2) Marine
Final
1980
Final
1980
Final
1980
0.19 ppb no
Acute no
11,000 ug/l
Chronic
none
Acute no
12,000 ug/l
Chronic
6,400 ug/l
45 FR 79318
1/13/80
ibid.
ibid.
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OSWER Directive 9481.00-11
Clean Air Act (CAA)
Regulatory Decision:
Nat. Emissions Current Under no FR
Standards for 1985 development 10/17/85
Hazardous Air
Pollutants (NESHAP)
Hazardous Waste Final : Listed no 40 CFR Part
Constituent 1985 ' 261
(App.VIII) ' App. VIII
B. RISK MANAGEMENT RATIONALE
RQ
The final adjusted RQ of 1000 pounds is based upon a chronictoxicity score of
10. This substance has recently been identified for assessment of carcinogenicity,
and the RQ will be reevaluated when that assessment is completed.
Contact: RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
WQC
Contact: Office of Water Regulations and Standards
202-382-5400 or FTS-382-5400
a. Human health: Methylene chloride is classified as a carcinogen, and under the
assumption of no threshold for a carcinogen, the recommended WQC is zero.
However, if zero cannot be obtained and exposure is via ingestion of water and
aquatic organisms, 0.19 ug/l is associated with an upper-bound excess lifetime risk
of 1.0E-6 [other risk levels to consider: 1.0E-5 (1.9 ug/l) and 1.0E-7 (0.019 ug/l)]. If
exposure is only via ingestion of aquatic organisms, the WQC associated with an
upper-bound excess lifetime risk or 1 .OE-6 is 15.7 ug/l. The criteria are based on
halomethanes as a class.
b. Aquatic toxicity: Water Quality criteria for the protection of aquatic life are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The "(LEL)" after the value indicates that the minimum data were not
available and the concentration given is not a criteria value but the lowest effect
level found in the literature. The values are based on halomethanes as a class - no
specific chemicals are cited.
V. SUPPLEMENTARY DATA
Chemical: Methylene Chloride
CAS No.: 75-09-2
Information is not available at this time.
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OSWER Directive 9481.00-11
Synonyms: Methane, dichloro- (8CI9CI); Aerothene MM; Chlorure de methylene
(French); Dichlormethan, uvasol; Dichloromethane; DCM; Freon 30; Methane
dichloride; Methylene bichloride; Methylene chloride (ACN); Methylene dichloride;
Metylenu chlorek (Polish); Narkotil; NCI-C50102; R30; Solaesthin; Solmethine;
WIN: G1G; 1,1-Dichloromethane.
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OSWER Directive 9481.00-11
REFERENCES FOR METHYLENE CHLORIDE
Burek, J.D., K.D. Nitschke, T.J. Bell, D.L Wackerle, R.C Childs, J.E. Beyer,
D.A.Dittenber, LW. Rampy, and M.J. McKenna, 1984. "Methylene chloride: A
two-year inhalation toxicity and oncogenicity study in rats and hamsters,"
Fundamentals of Applied Toxicology, 4:30-47.
EPA (U.S. Environmental Protection Agency), 1979. Water-Related Environmental
Fate of 129 Priority Pollutants. EPA/440-4-79-029, Washington, D.C, December.
EPA (U.S. Environmental Protection Agency), 1985. Health Assessment Document
for Chloroform, EPA 600/8-84-004F, Office of Health and Environmental
Assessment, Washington, D.C., September.
NTP (National Toxicology Program), 1984. NTP Technical Report on the Toxicology
and Carcinoqenesis Studies of Methvlene Chloride (CAS No. 75-09- 2) in F344/N
Rats and B6C3F^ Mice (Inhalation Studies). NTP Technical Report No. 291,
USDHHS (NIH) Publication No. 85-2562, Research Triangle Park, North Carolina.
Other Resource Documents
American Conference of Governmental Industrial Hygienists, 1980, Documentation
of the Threshold Limit Values. 4th ed. Cincinnati, Ohio, 1980,488 pp.
McCoy and Associates, "Physical/Chemical Data Compendium for Common
Solvents," The Hazardous Waste Consultant. Vol. 4, No. 6, Nov./Dec., 1986, pp.
4-1 to 4-32.
National Institute for Occupational Safety and Health, Criteria for a Recommended
Standard—Occupational Exposure to Methvlene Chloride. DHEW Publication
No. (NIOSH) 76-138, Washington, D.C., March, 1976.
National Institute for Occupational Safety and Health, Registry of Toxic Effects
of Chemical Substances-Data Base. Washington. D.C.. 1983.
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OSWER Directive 9481 00-11
SAX, N.I., Dangerous Properties of Industrial Materials. 4th ed. Van Nostrand
Reinhold Co., New York, 1975,1,258 pp.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Halomethanes. EPA/440-5-80-051, Office of Water Regulations and
Standards, Criteria and Standards Divisions, Washington, D.C., October 1980.
U.S. Environmental Protection Agency, Health Effects Assessment for Methylehe
Chloride. Final Draft, ECAO-CIN-HO-28, Environmental Criteria and
Assessment Office, Cincinnati, Ohio, September 1984.
Weast, R.E., ed., Handbook of Chemistry and Physics. 62nd ed. CRC Press,
Cleveland, Ohio, 1981,2,332 pp
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CHEMICAL AND PHYSICAL PROPERTIES OF
1,1,1-TRICHLOROETHANE
Summary
CAS Number: 71-55-6
Chemical Formula: CHaCCIa
lUPACName: 1,1,1-Trichloroethane
Important Synonyms and Trade Names: Methyl chloroform, chlorothene,
1,1,1-TCA
Chemical and Physical Properties
Molecular Weight:
Boiling Point:
Melting Point:
Specific Gravity:
Solubility in Water:
Solubility in Organics:
Henry's Law Constant:
Vapor Pressure:
Vapor Density:
Viscosity:
Flash Point:
133.4
74.19C
-30.4°C
1.34 at 20°C (liquid)
480-4,400 mg/liter at 20°C (several divergent values were
reported in the literature)
Soluble in acetone, benzene, carbon tetrachloride,
methanol, ether, alcohol, and chlorinated solvents
4.92 x 10-3 atm -m3/mole at 25°C
123mmHgat20°C
4.63
0.889 centipoise at 16°C
Not flammable
Log Octanol/Water Partition Coefficient: 2.17
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OSWER Directive 9431.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
1,1,1-Trichloroethane; CAS No. 71-55-6 (Revised 09/30/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic.toxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4. •-"
STATUS OF DATA FOR 1,1,1-Trichloroethane
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: under review
III. Drinking Water Health Advisories: none
IV. Regulatory Actions: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may
exist for certain toxic effects such as cellular necrosis, but may not exist for other
toxic effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6 . Preparation Date: 03/18/87
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
No adverse effects NOAEL: 500ppm(air) 1000 1 9E-2
(2730 mg/cu.m) mg/kg/day
Guinea Pig 6-Month converted to
Inhalation Study 90/mg/kg/day
Torkelson etal.,
1958
Slight growth LOAEL: 650 ppm (air)
retardation (3550 mg/cu.m)
(converted to
Guinea Pig 120 mg/kg/day)
2-3 Month
Inhalation Study
Adams etal., 1950
* Dose Conversion Factors & Assumptions: dose (mg/cu.m) x 7 hours/24 hours x 5
days x (0.3) x (0.23 cu.m/day/0.43 kg) where: 0.3 is the assumed inhalation
retention factor, and 0.23 cu.m/day /0.43 kg are the assumed ventilation rate
and body weight of the guinea pig, respectively.
2. PRINCIPAL AND SUPPORTING STUDIES
Torkelson, T.R., F. Oven, D.D. McCollister and V.K. Rowe. 1958. Toxicity of 1,1,1 -
trichloroethane as determined on laboratory animals and human subjects. Am. Ind.
Hyg.Assoc.J. 19:353-362.
Adams, E.M., H.C. Spencer, V.K. Rowe and D.D.Irish. 1950. Vapor toxicity of 1,1,1 -
trichloroethane (methyl chloroform) determined by experiments on laboratory
animals. Arch. Ind. Hyg. Occup. Med. 1: 225-236.
Torkelson et al. (1958) exposed groups of rats, rabbits, guinea pigs and
monkeys to 1,1,1 -trichloroethane vapor at concentrations of 500,1000, 2000 or
10,000 ppm. From these studies, it was determined that the female guinea pig was
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OSWER Directive 9481.00-11
the most sensitive species of those tested. At 500 ppm, groups of eight male and
eight female guinea pigs showed no evidence of adverse effects compared with
unexposed and air-exposed controls after exposure for 7 hours/day, 5 days/week for
6 months. Groups of five female guinea pigs exposed to 1000 ppm 1,1,1-
trichloroethane vapor 3 hours/day, 5 days/week for 3 months had fatty changes in
the liver and statistically significant increased liver weights. Thus, this study defined
a NOAEL of 500 ppm (2730 mg/cu.m) in guinea pigs.
Adams etal. (1950) subjected groups of 6-10 male and female guinea pigs to
650 ppm 1,1,1-trichloroethane vapor 7 hours/day, 5 days week for 2-3 months.
These animals exhibited a slight'depression in weight gain compared with both air-
exposed and unexposed controls, thereby establishing a LOAEL of 650 ppm (3550
mg/cu.m) in guinea pigs.
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 1000. Factors of 10 each were employed for use of a subchronic assay, for
extrapolation from animal data, and for protection of sensitive human sub-
populations.
MF = 1
4. ADDITIONAL COMMENTS
The 1,1,1-trichloroethane samples used byTorkelson etal. (1958) were found
to be 94-97% pure while the samples used in the Adams et al. (1950) study had a
purity of greater than or equal to 99%.
The effects of 1,1,1-trichloroethane vapor have been investigated in mice
(Quastetal., 1984; McNuttetal., 1975), rats (Quast etal., 1978), and rabbits and
dogs (Pendergast et al., 1967). The only chronic oral exposure study was conducted
by NCI (1977) in rats. The observations from these studies and from Torkelson et al.
(1958) and Adams etal. (1950) are somewhat inconsistent, thus, making conclusions
difficult regarding which dose levels of 1,1,1-trichloroethane result in adverse
effects. For example, exposure to 650 ppm in the Adams et al. (1950) inhalation
study was associated with slight growth retardation in guinea pigs. Further review
of this study indicates that 1500 ppm exposure also caused slight growth
retardation without causing any organ specific adverse effects following 1-3 months
exposure. These observations are in contrast with those of Torkelson et al. (1958)
who observed adverse effects in the liver and lungs of guinea pigs exposed to 1000
ppm for 90 days. Results and technical evaluation of recent inhalation studies in
mice (Quast etal., 1984) and rats conducted by Dow Chemical will be of greater
value for the overall RfD consideration for 1,1,1-trichloroethane.
5. CONFIDENCE IN THE RfD
Study: Low Data Base: Medium RfD: Medium
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OSWER Directive 9481.00-11
Although both the Adams et al. (1950) and Torkelson et al. (1958) studies used
both sexes of several species, the number of animals at each dose level was limited,
the length of exposure varied with different dose levels and few toxic endpoints
were examined. Confidence in these studies is thus considered low. The data base is
fairly comprehensive; however, results from these studies are somewhat
inconsistent and some of the more recent studies have yet to be critically evaluated.
Confidence in the data base is, therefore, rated medium while the RfD is rated
medium to low.
6. DOCUMENTATION AND REVIEW
The only U.S. EPA documentation at present is on IRIS.
Agency RfD Work Group Review: 05/31/85, 07/08/85, 07/22/85, 05/15/86
Verification Date: 05/15/86
7. U.S. EPA CONTACTS
Primary: M.L. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
Secondary: Y. Patel FTS/382-7585 or 202/382-7585
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6
This chemical is among those substances evaluated by the U.S. EPA for
evidence of human carcinogenic potential. This does not imply that this chemical is
necessarily a carcinogen. The evaluation for this chemical is under review by an
inter-office Agency work group. A risk assessment summary will be included on IRIS
when the review has been completed.
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III. DRINKING WATER HEALTH ADVISORIES
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6
Information is not available at this time.
IV. REGULATORY ACTIONS '
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-55-6 Preparation Date: 09/30/87
INTERPRETATION OF REGULATORY ACTION INFORMATION
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Regulatory actions are frequently not
updated at the same time. Carefully read the dates for the regulatory actions (in
this section) and the verification dates for the risk assessments (in sections I & II), as
this may explain apparent inconsistencies. Also note that some regulatory actions
consider factors not related to health risk, such as technical or economic feasibility;
Such considerations are indicated for each action following (Econ/Tech Feasibility
entry). In addition, not all of the regulatory actions listed in this section involve
enforceable federal standards. Please direct any questions you may have
concerning the use of risk assessment information in making a regulatory decision
to the U.S. EPA contact listed for that particular regulatory action. Users are
strongly urged to read the background information on each regulatory action in
Appendix D in Service Code 4.
A. AIR
Information is not available at this time.
B. WATER
MAXIMUM CONTAMINANT LEVEL GOAL (MCLG); for Drinking Water
Value (status) - 200 ug/L (Final, 1987)
Considers technological or economic feasibility? -- NO
Discussion -- An MCLG of 200 ug/L for 1,1,1-trichloroethane is proposed based upon
a DWELand an assumed drinking water contribution of 20%. A DWELof 1.0 mg/L
was calculated based on liver toxicity in mice (inhalation study).
Reference -- 52 FR 25690 (07/08/87)
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US EPA Contact-- Office of Drinking Water
202/382-5543 or FTS/382-5543
C TOXICS/PESTICIDES
Information is not available at this time.
D. SUPERFUND
Information is not available at this time.
V. SUPPLEMENTARY DATA
Chemical: 1,1,1-Trichloroethane
CAS No.: 71-S5-6
Information is not available at this time.
SYNONYMS: ETHANE, 1,1,1-TRICHLORO-; AEROTHENE TT; CHLOROETENE;
CHLOROETHENE; CHLOROETHENE NU; CHLOROFORM, METHYL-; CHLOROTHANE
NU; CHLOROTHENE; CHLOROTHENE(lnhibited); CHLOROTHENE NU;
CHLOROTHENE VG; CHLORTEN; INHIBISOL; METHYLCHLOROFORM; METHYL
CHLOROFORM (ACGIH.DOT); METHYLTRICHLOROMETHANE; NCI-C04626; RCRA
WASTE NUMBER U226; SOLVENT 111; STROBANE; alpha-T; 1,1,1-TCE; 1.1,1-
TRICHLOORETHAAN (Dutch); 1,1,1-TRICHLORAETHAN (German); TRICHLORO-1,1,1-
ETHANE (French); alpha-TRICHLOROETHANE; 1,1,1-TRICHLOROETHANE; 1,1,1-
TRICHLOROETHANE (DOT); 1,1,1-TRICLOROETANQ (Italian); TRI-ETHANE; UN 2831
(DOT)
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REFERENCESFOR1.1.1-TRICHLOROETHANE
EPA (U.S. Environmental Protection Agency), 1980. Ambient Water Quality Criteria
for Chlorinated Ethanes, EPA/440-5-80-029, Washington, D.C., October
NCI (National Cancer Institute), 1977. Bioassav of 1.1.1 -Trichloroethane for Possible
Carcinoqenicitv. NCI Carcinogenesis Technical Report Series 3, DHEW
Publication (NIH) 77-803, Washington, D.C
NTP (National Toxicology Program), 1984. Annual Plan for Fiscal Year 1984. NTP-84-
023, DHHS Public Health Service, Research Triangle Park, N.C.
Other Resource Documents
International Agency for Research on Cancer, "Some Halogenated Hydrocarbons,
IARC Monograph on the Evaluation of the Carcinogenic Risks of Chemicals to
Humans. Vol. 20, World Health Organization, Lyon, France, 1979, pp. 515-531.
National Institute for Occupational Safety and Health, Criteria for a Recommended
Standard—Occupational Exposure to 1.1.1-Trichloroethane (Methyl
Chloroform). DHEW Publication (NIOSH) 76-184. Washington. D.C.. 1976.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base. Washington. D.C.. October, 1983.
U.S. Environmental Protection Agency, Health Effects Assessment for 1.1,1 -
Trichloroethane. Final Draft. ECAO-ClN-HO-05, Environmental Criteria and
Assessment Ofice, Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Water Related Environmental Fate of 129
Priority Pollutants.EPA/440-4-79-029. Washington, D.C., December, 1979.
Verschueren, K., Handbook of Environmental Data on Organic Chemicals, Van
Nostrand Reinhold Co., New York, 1977,659 pp.
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Weast, R.E., ed., Handbook of Chemistry and Physics. 62nd ed.. CRC Press,
Cleveland, Ohio, 1981,2332 pp.
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CHEMICAL AND PHYSICAL PROPERTIES OF
TRICHLOROETHYLENE
Summary
*
CAS Number: 79-0.t*'6
Chemical Formula: C2HC1a
IUPAC Name: Trichloroethene
Important Synonyms and Trade Names: Trichloroethene, TCE, and ethylene
trichloride
Chemical and Physical Properties
Molecular Weight: 131..5
Boiling Point: 8?c
Melting Point: -73°C
Specific Gravity: 1.4642 at 20°C
Solubility in Water: 1,000 mg/liter
Solubility in Organics: Soluble in alcohol, ether, acetone, and chloroform
Henry's Law Constent: 8.92 x 10-3 atm-m3/mole at 25°C
Vapor Pressure: 60 mm Hg at 20°C
Vapor Density: 4.53
Viscosity: 0.610 centipoise at 15.6°C
Flash Point: 32°C (closed cup)
Log Octanol/Water Partition Coefficient: 2.29
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INTEGRATED RISK INFORMATION SYSTEM (IRIS):Chemical Files
Trichloroethylene; CAS No. 79-01-6 (Revised 03/31/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic-'toxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Trichloroethylene
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: under review
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Trichloroethylene
CAS No.: 79-01-6
A risk assessment for this chemical is under review by an EPA work group.
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8. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Trichloroethylene
CAS No.: 79-01-6 Preparation Date: 02/18/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification: B2, probable human carcinogen; based on positive responses in
two strains of mice by two routes and suggestive increases in tumor
incidences in male rats by gavage. Supporting evidence does not
downgrade the classification. • '-
1. HUMAN DATA
Three cohort studies of exposed workers (Axelson, 1978; Tola et al., 1980;
Malek et al., 1979) found no excess cancer risk associated with trichloroethylene
exposure. Results from a case-control study of malignant lymphoma cases by
Hardell (1981) were suggestive of an association between trichloroethylene
exposure and malignant lymphoma, but the study had various limitations. Studies
by Novptna et al. (1979) and Paddle (1983) of liver cancer cases found no association
with trichloroethylene exposure. No controls were used in the latter two studies.
2. ANIMAL DATA
Positive evidence of carcinogenicity has generally come from studies of mice.
Negative results have been obtained from gavage treatment of Osborne-Mendel
rats, Sprague-Dawley rats and ICR/Ha Swiss mice (NCI, 1976; Maltoni, 1979;
Henscnleretal., 1984). The NCI (1976) study may be inconclusive due to high
mortality and the Maltoni (1979) exposure was carried out for a less-than-lifetime
period. An NTP (1983) study found a small increase in incidence of renal
adenocarcinomas in male Fischer 344 rats treated by gavage. This was significant by
statistical tests that took survival differences into account, but not by the
unadjusted Fisher Exact test.
Henschler et al. (1980) found a significant increase in malignant lymphomas in
female Han:NMRI mice exposed by inhalation. The spontaneous incidence of
lymphomas in controls was also high. Inhalation treatment of the following
produced negative results: Charles River rats; Han:Wist rats, Syrian hamsters and
male Han:NMRI mice (Bell etal., 1978; Henschler etal., 1980).
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Trichloroethylene did not serve as either an initiator or as a complete skin
carcinogen (van Duuren etal., 1979) Trichloroethylene oxide was also negative in
an initiation-promotion assay and after s.c. injection.
Male and female B6C3F1 mice were treated 5 days/week for 78 weeks by corn
oil gavage with epoxide-stabilized trichloroethylene. Doses were TWA were 1169
and 2339 mg/kg for males and 869 and 1739 mg/kg forfemales.cinomas(NCI, 1976).
A repeat bioassay confirmed the observation of increased incidence of
hepatocellular carcinoma. In this study, male and female B6C3F1 mice were treated
with purified trichloroethylene containing no detectable epoxides by corn oil
gavage of 1000 mg/kg/day, 5 days/week for 103 weeks (NTP, 1983).
3. SUPPORTING DATA
Trichlorpethylene of various grades of purity was negative or weakly positive
in mutagenicity assays with S. typhimurium, E. coli and S. pombe. It was mutagenic
for both S. cerevisiae and in the mouse spot test. While tests for chromosomaf
aberrations were negative, trichloroethylene produced mitotic recombination in S.
cerevisiae and borderline positive responses in assays of SCE (after occupational
exposure) and unscheduled DMA synthesis. Metabolites of trichloroethylene have
likewise produced variable, largely negative, responses (U.S. EPA, 1985).
Trichloroethylene oxide, however, has been shown to transform Syrian hamster
embryo cells after in vitro exposure (DiPaolo and Doniger, 1982).
B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 1.1E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/L)
3E + 2 ug/L 3E +1 ug/L 3 ug/L 3.2E-7 LM, extra
risk
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2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Slope Reference
Tumor Type Administered Human Equivalent Incidence Factor
Mouse/B6C3F1, Route: Oral, gavage
male and
female;
hepatocellular
carcinomas mg/kg/day
mg/kg/day
/mg/kg
/day
male 0
1000
female 0
1000
male 0
1169
2339
female 0
869
1739
0
47.39
0
45.62
0
45.11
85.80
0
31.65
61.43
8/48
30/50
2/49
13/49
1/20
26/50
31/48
0/20
4/50
11/47
.9E-2
8.0E-3
1.8E-2
5.8E-3
NTP, 1983
NCI, 1975
3. ADDITIONAL COMMENTS
Metastases to the lungs were observed in one control male and five treated
males in the NTP (1983) study. Survival of treated males was decreased by
comparison with controls. Doses for the NCI (1976) study are TWA. There was little
toxicity in this study not attributed to tumor development. The slope factor used
for the unit risk is the geometric mean of the four slope factors above.
Data on metabolism of gavaged trichloroethylene in Swiss Cox mice (Buben
and O'Flaherty, 1985) suggest that the NTP (1983) gavage assay dose of 1000
mg/kg/day is within the linear portion of the dose/amount metabolized curve; the
high doses of the NCI (1976) bioassay approach the saturation of metabolism.
Human equivalent lifetime average metabolized doses were calculated as follows:
human equivalent dose = weeks treated/weeks observed x 5 days/7 days x
animal metabolized dose in (mg/day) x
(WH/WA)**2/3
where: WH = 70 kg
WA = 0.04 kg male mice, 0.035 female mice (NTP, 1983); 0.033
kg male, 0.026 female (NCI, 1976)
The unit risk should not be used if the water concentration exceeds 3E + 4
ug/L, since above this concentration the slope factor may differ from that
stated.
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4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE RISK ESTIMATE
Slope factors for male and female B6C3F1 mice from two independent studies
are very dose (all within a factor of 3). Adequate numbers of animals were studied,
and tumor incidences were significantly elevated comparably, although the follow-
up studies had only only one positive dose group. Confidence in the risk estimate is
rated medium to high.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
C. INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 1.3E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
8E1 ug/cu.m 8ug/cu.m 8E-1 ug/cu.m 1.3E-6 LM, extra
risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Calculated from oral data as follows:
Unit risk = 1.3E-2 x9.9E-5
where: 1.3E-2 = slope factor (/mg metabolized dose/kg/day)
9.9E-5 = body metabolite load
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3. ADDITIONAL COMMENTS
Data by Monster etal. (1976) were used as the basis for estimation of the
amount of trichloroethylene metabolized by humans exposed to 1 mg/cu.m. The
mean amount metabolized was 439 mg for four subjects exposed to 70 ppm for 4
hours. The amount of metabolite formed following continuous 24-hour exposure
to 1 ug/cu.m was estimated to be 9.9E-5 mg/kg/day.
The unit risk should not be used if the air concentration exceeds 8E + 3
ug/cu.m, since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
There are data from metabolism studies on inhalation of trichloroethylene by
human subjects to justify dose assumptions. Confidence in this inhalation risk
estimate derived from oral data is rated medium.
Note: Although the statement of confidence in the quantitative estimate is a ,
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
D. DOCUMENTATION AND REVIEW
1. REFERENCES
U.S. EPA. 1985. Health Assessment Document for Trichloroethylene. Prepared by
the Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Research Triangle Park, NC. EPA 600/8-82-006F.
NTP (National Toxicology Program). 1983. Carcinogenesis Bioassay of
Trichloroethylene (CAS Nor. 79-01-6). NTP Report No. 81-84. Dept. HHS. Publ. No.
83-1799.
NCI (National Cancer Institute). 1976. Carcinogenicity Bioassay of Trichloroethylene
(CAS No. 79-02-6). Carcinogenesis Technical Report Series No. 2.
2. REVIEW
The 1985 Health Assessment Document for Trichloroethylene received both an
Agency and external review.
Agency WorkGroup Review: 12/04/86
Verification Date: 12/04/86
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3. U.S. EPA CONTACTS
Primary: R. Bellies 202/382-7436 or FTS/382-7436
Office of Research and Development
Secondary: C. Chen 202/382-5898 or FTS/382-5898
Office of Researched Development
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical: Trichloroethylene
CAS No.: 79-01-6 Preparation Date: 03/31/87
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
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A. RISK MANAGEMENT ACTIONS
Risk Status Risk Considers
Management Management Econ/Tech
Action Date Value Feasibility Reference
Reportable Proposed 100 Ibs no 52 FR 8140
Quantity (RQ) 1987-f 03/16/87
Clean Air Act (CAA)
Regulatory Decision:
Nat. Emissions Current Under no 50 FR 52422
Standards for 1985 development 12/23/85
Hazardous Air
Pollutants (NESHAP)
B. RISK MANAGEMENT RATIONALE
RQ
The proposed RQ for trichloroethylene is 100 pounds, based on potential
carcinogenicity. The available data indicate a hazard ranking of low, based on a
potency factor of 0.070 (mg/kg/day)-1 and weight-of-evidence classification 82,
which corresponds to an RQ of 100 pounds.
Contact: Office of Emergency and Remedial Response
202/382-2180 or FTS/382-2180
CAA Regulatory Decision
NESHAP: Trichloroethylene (TCE) is a probable human carcingen (EPA Group
B2) and according to EPA's preliminary risk assessment from ambient air exposures,
public health risks are significant (4.1 cancer cases per year and maximum lifetime
individual risks of 9.4x10-5). Thus, EPA indicated that it intends to add TCE to the
list of hazardous air pollutants for which it intends to establish emission standards
under section 112(b)(1 )(A) of the Clean Air Act. The EPA will decide whether to add
TCE to the list only after studying possible techniques that might be used to control
emissions and further assessing the public health risks. The EPA will add TCE to the
list if emissions standards are warranted.
Contact: Chief, Pollutant Assessment Branch
FTS/629-5645 or 919/541-5645
= = =
V. SUPPLEMENTARY DATA
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available at this time.
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SYNONYMS: ETHYLENE,TRICHLORO-; ACETYLENE TRICHLORIDE; ALGYLEN;
ANAMENTH; BENZINOL; BLACOSOLV; BLANCOSOLV; CECOLENE; CHLORILEN; 1-
CHLORO-2.2-DICHLOROETHYLENE; CHLORYLEA; CHLORYLEN; CHORYLEN;
CIRCOSOLV; CRAWHASPOL; DENSINFLUAT; 1J-DICHLORO-2-CHLOROETHYLENE;
DOW-TRI; DUKERON; ETHINYL TRICHLORIDE; ETHYLENE TRICHLORIDE; FLECK-FLIP;
FLOCK FLIP; FLUATE; GEMALGENE; GERMALGENE; LANADIN; LETHURIN;
NARCOGEN; NARKOGEN; NARKOSOID; NCI-C04S46; NiALK; PERM-A-CHLOR;
PERM-A-CLOR; PETZINOL; PHILEX'RCRA WASTE NUMBER U228; TCE;
THRETHYLEN; THRETHYLENE; TRETHYLENE; TRI; TRIAD; TRIAL; TRIASOL;
TRICHLOORETHEEN (Dutch); TRKHLOORETHYLEEN.TRI (Dutch); TRICHLORAETHEN
(German); TRICHLORAETHYLEN,TRI (German); TRICHLORAN; TRICHLOREN;
TRICHLORETHENE (French); TRICHLORETHYLENE; TRICHLORETHYLENE, TRI
(French); TRICHLOROETHENE, TRICHLOROETHYLENE; 1,1,2-TRICHLOROETHYLENE;
1,2,2-TRICHLOROETHYLENE; TRICHLOROETHYLENE (ACGIH.DOT); TRI-CLENE;
TRICLORETENE (Italian); TRICLOROETILENE (Italian); TRIELENE; TRIELIN; TRIELINA
(Italian); TRIKLONE; TRILEN; TRILENE; TRIUNE; TRIMAR; TRIOL; TRI-PLUS; TRI-PLUS
M; UN 1710 (DOT); VESTROL; VITRAN; WESTROSOL
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Verschueren, K., Handbook of Environmental Data on Organic Chemicals.
Van Nostrand Reinhold Co., New York, 1977, 659 pp.
Waters, E. M., Gerstner, H.B., and Huff, J.E., "Trichloroethyiene: 1. An Overview,'
J. Toxicol. Enivron. Health 2:674-700.
^
Weast, R.E., ed.f Handbook of Chemistry and Physics. 62nd ed.. CRC Press,
Cleveland, Ohio, 1981, 2,332 pp.
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REFERENCES FOR TRICHLOROETHYLENE
NCI (National Cancer Institute), 1976. Bioassay of Trichloroethylene for Possible
Carcinoqenicity. CAS No. 79-01-6, NCI Carcinogenesis Technical Report Series
No. 2, DHEW Publication No. (NIH) 76-802, Washington, D.C.
NTP (National Toxicology Program), 1982. Carcinoqenesis Bioassay of
Trichloroethvlene. CAS No. 79-01-6, NTP 81-84, NIH Publication No. 82-1799.
Other Resource Documents
International Agency for Research on Cancer, "Some Halogenated Hydrocarbons,"
IARC Monograph on the Evaluation of Carcinogenic Risk of Chemicals to
Humans, Vol. 20, World Health Organization, Lyon, France, pp 545-572.
McCoy and Associates, "Physical/Chemical Data Compendium for Common
Solvents," The Hazardous Waste Consultant. Vol. 4, No. 6, Nov./Dec, 1986, pp
4-1 to 4-32.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base. Washington, D.C., October, 1983.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Trichloroethylene. EPA/400-5-80-077, Office of Water Regulations and
Standards, Criteria and Standards Division, Washington, D.C., October, 1980
U.S. Environmental Protection Agency, Health Assessment Document for
Chloroform. EPA/600-8-84-004F, Office of Health and Environmental
Assessment, Washington, D.C., September, 1984.
U.S. Environmental Protection Agency, Health Assessment Document for
Trichloroethvlene. Review Draft. EPA/600-8-82-0068, Washington, D.C., 1983.
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December, 1979.
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ACL
CASE STUDY 3a
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CONTENTS
SECTION PAGE
1.0 EXECUTIVE SUMMARY 1-1
2.0 INTRODUCTION 2-1
2.1 FACILITY DESCRIPTION 2-1
2.2 APPROACH TO ACL DETERMINATION 2-3
2.3 REPORT ORGANIZATION 2-4
3.0 IDENTIFICATION OF ACL CONSTITUENTS 3-1
3.1 HAZARDOUS CONSTITUENTS IN THE WASTE 3-1
3.2 EXTENT AND DEGREE OF CONTAMINATION 3-1
4.0 GENERAL INFORMATION 4-1
4.1 LAND USE 4-1
4.2 WATER USE AND USERS 4-1
4.3 PRECIPITATION 4-4
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION 5-1
5.1 REGIONAL GEOLOGY 5-1
5.2 SITE GEOLOGY 5-4
5.3 GROUND-WATER HYDROLOGY 5-7
5.4 SURFACE WATER HYDROLOGY 5-14
6.0 EXPOSURE PATHWAYS 6-1
6.1 POTENTIAL HUMAN EXPOSURE 6-1
6.2 POTENTIAL ENVIRONMENTAL EXPOSURE 6-3
6.3 MAXIMUM ALLOWABLE EXPOSURE CONCENTRATIONS 6-4
7.0 DEVELOPMENT OF ACLs 7-1
8.0 GROUND-WATER MONITORING PROGRAM 8-1
8.1 COMPLIANCE MONITORING 8-1
in
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CONTENTS (continued)
REFERENCES
R-1
APPENDICES
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
A-1
B
CHEMICAL AND PHYSICAL PROPERTIES AND IRIS
(INTEGRATED RISK INFORMATION SYSTEM)
DATA BASE FOR TOLUENE AND
1,1,2-TRICHLORO€THANE
B-1
TYPICAL WETLAND SPECIES FOR COUNTY IN WHICH
FACILITY CIS LOCATED
C-1
IV
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TABLES
NUMBER PAGE
3-1 Hazardous Constituents Present in Wastes 3-2
3-2 Maximum Concentrations (mg/l) of Toluene and 1,1,2- 3-4
Trichloroethane During the Period 1978-1986
3-3 Concentrations (mg/l) of Toluene and 1,1,2-Trichloroethane 3-6
for 1981 and 1986
4-1 Inventory of Wells Within One Mile of the Facility 4-3
4-2 Monthly Precipitation 4-4
5-1 Ground-Water Elevations (1984) 5-10
5-2 Average Properties of the Uppermost Aquifer 5-12
5-3 Estimated Hydraulic Conductivities of the Uppermost Aquifer 5-13
6-1 Allowable Exposure Levels 6-6
7-1 Proposed Alternate Concentration Limits 7-1
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OSWER Directive 9481.00-11
FIGURES
NUMBER PAGE
2-1 Site Layout of Facility C 2-2
3-1 Monitoring and Compliance Well Locations 3-3
3-2 Isopleths for Toluene (mg/l) Based on Concentrations in 1981 3-8
3-3 Isopleths for Toluene (mg/l) Based on Concentrations in 1986 3-9
3-4 Isopleths for 1,1,2-Trichloroethane (mg/l) Based on 3-10
Concentrations in 1981
3-5 Isopleths for 1,1,2-Trichloroethane (mg/l) Based on 3-11
Concentrations in 1986
4-1 Topographic Map and Off-site Well Locations 4-2
5-1 Regional Topography 5-2
5-2 Site Topography 5-3
5-3 Location of Cross Sections 5-5
5-4 Cross Section A-A' 5-6
5-5 Cross Section B-B' 5-8
5-6 Water Table Contours 5-11
6-1 Flow Diagram of Pollutant Migration Pathways/Fate 6-2
VI
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OSWER Directive 9431 00-H
1.0 EXECUTIVE SUMMARY
Case Study 3a is a hypothetical example of an application by Facility C for
alternate concentration limits (ACLs) under 40 CFR 264.94(b) for hazardous
constituents that have been detected in the ground water at the facility. This case
study illustrates the approach outli-ned in Cases 1 and 3 of Part I of the ACL Guidance
Document (EPA, 1987a). Case 3 of Part I (Chapter 1) applies to units located over
useable ground water. Under Case 3, if the leading edge of the plume extends off
the facility property, the point of exposure (POE) will be assumed to be no farther
from the point of compliance (POC) than the facility property boundary. Case 1
applies to regulated units at which no ground-water contamination was detected at
the time of permit issuance. In this case, the POE will be established at the POC.
This hypothetical ACL application is for four closed cells under Case 3 and for one
active cell under Case 1.
Facility C is located in a rural area in the northeastern United States. Two
hazardous constituents have been detected in the ground water at the site: toluene
and 1,1,2-trichloroethane. The contaminated ground water at Facility C has
migrated off-site and is discharging into surface waters adjacent.to the facility.
Ground water is the principal source of water for nearby residences, all of which are
upgradient of the facility. Surface waters in the area are used for irrigation as well
as swimming, boating, and fishing.
Potential exposure pathways considered in this application include human
ingestion of contaminated water and fish and direct exposure of aquatic organisms
to contaminated surface waters. It was concluded that the areas of risk did not
include a cranberry bog that uses water for irrigation from a pond recharged by
ground water. This conclusion was based on the facts that contaminant
concentrations in the ground water and surface water immediately upgradient of
the bog are below health-based levels and that the concentrations have been
decreasing.
Allowable exposure levels for: 1) human drinking, 2) human drinking and fish
ingestion, 3) acute ecosystem exposure, and 4) chronic ecosystem exposure were
developed, compared, and evaluated for toluene and 1,1,2-trichloroethane. The
1-1
-------
OSWER Directive 9481.00-11
lowest allowable exposure concentrations for each of the contaminants were used
to develop the proposed ACLs.
Facility C is committed to a corrective action program because the
contaminant concentrations at the point of compliance for toluene and 1,1,2-
trichloroethane are above the proposed ACLs for those constituents.
1-2
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OS WE R Directive 9481 00-11
2.0 INTRODUCTION
Part I of the ACL Guidance Document describes five cases that show how the
ACL guidance and policy should be applied to five different site-specific situations.
This ACL application has been developed based on the situations described in Case 1
and Case 3. The four closed disposal units (described in Section 2.1, below) of
Facility C are representative of Case 3 because Facility C is located over useable
ground water and the plume of contamination from these units extends off the
facility property. The new active disposal unit is representative of Case 1 because
leakage from this unit has not been detected. This demonstration is part of the
facility's Part B permit application for an operating permit covering one active unit
and post-closure care for four closed units.
2.1 Facility Description
Facility C contains five regulated units: four closed landfill cells and one active
landfill cell as shown in Figure 2-1. The closed units are the Northeast, South,
Western and the Northwest Disposal Cells. The active landfill cell is designated Nu-
Cell.
Between 1977 and late 1982, the four closed cells received bulk and
containerized hazardous wastes generated by industrial facilities in the local area.
These cells are clay-lined. Ground-water contamination by toluene was detected
on-site and off-site in 1978. Contamination by 1,1,2-trichloroethane was detected
on-site in 1979. The contamination appeared to originate from at least two of the
four units: the Western Disposal Cell and the Northwest Disposal Cell. Efforts were
made to contain the leaks in 1978,1979, and 1980.
In 1980, the facility began construction of the Nu-Cell, an engineered landfill
cell, and temporarily suspended receipt of bulk hazardous wastes until completion
of the engineered cell. The new disposal cell consisted of a clay liner overlain by a
secondary leachate collection system, a synthetic impervious liner, and the primary
leachate collection system. It was completed in 1981 and began accepting
hazardous wastes with the same characteristics as the wastes disposed of in the
other units. The four inactive units were removed from service in late 1982, when
the leaking clay liners were determined to be irreparable.
2-1
-------
OSWER Directive 9481.00-1
\— South Disposal
Call
0 250 500
Seal*. F«at
FIGURE 2-1. SITE LAYOUT OF FACILITY C
2-2
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OSWER Directive 9481 00-11
In 1983, the bulk and containerized wastes were removed from the four
inactive units, and the units were capped and graded. These wastes and some
contaminated soils were placed in the Nu-Cell. However, some contaminated soils
were not removed, and the ground-water quality did not return to background
levels. The incomplete source removal necessitated that the facility meet post-
closure requirements under 40VCFR 265.117 through 265.120, including site
maintenance and ground-water monitoring. Monitoring has continued to detect
toluene and 1,1,2-trichloroethane in the ground water both on- and off-site and in
surface waters as far downgradient as Swamp A. Further details on the operating
characteristics of the facility are provided in Section B of the Part B permit
application.
2.2 Approach to ACL Demonstration
As described in Sections 4.1 and 4.2 of this application, Facility C is located'm
glacial terrain upgradient of a wetland area. The ground water passing beneath
the facility is not currently used for domestic, commercial, or industrial purposes
prior to discharge into the wetland area. The ACL demonstration is based on
wetland receptors and on human ingestion of contaminated water and fish for the
two hazardous constituents, toluene and 1,1, 2-trichloroethane. As appropriate for
Case 3, the point of exposure (POE) for the four closed units will be assumed to be
no farther from the point of compliance (POC) than the facility property boundary.
However, since the northern disposal cells are immediately adjacent to the property
boundary on their downgradient sides, the POE (facility boundary) and the POC are
essentially the same. Therefore, no attenuation will be accounted for in the
derivation of the ACLs for these units.
In addition to the application for ACLs for the closed units, this demonstration
is an application for ACLs for the Nu-Cell. Although contamination has been
detected in the Nu-Cell POC wells, the Nu-Cell is not believed to be leaking. As
regulatory authorities have agreed (see Section F of the Part B permit application),
the contamination in the Nu-Cell POC wells originates from the closed landfills.
Because the Nu-Cell is not leaking, it is similar to Case 1 in the ACL Guidance
Document. Therefore, the potential POE is assumed to be at the POC (i.e., at the
waste management unit boundary). No attenuation should be presumed for
2-3
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OSWER Directive 9481 00-11
contaminants that leach from a unit in the future, nor should fate and transport
arguments be used to support ACL demonstrations if no ground-water contaminant
plume exists at the time of permit issuance. Consequently, ACLs for the Nu-Cell will
be set at allowable health and environmental exposure levels.
The Nu-Cell has received waste from the old units and also receives new waste
of similar composition. Based on this fact, any releases from the Nu-Cell would
likely consist of the same constituents as have been released from the closed units.
Therefore, the application for ACLs at the Nu-Cell's POC are for the same
constituents as at the four closed cells.
Wetland aquatic organisms could be adversely impacted by exposure to the
two hazardous constituents. In addition, there is potential for human exposure
through ingestion of contaminated surface or ground water and through ingestion
of both contaminated water and aquatic organisms, principally fish. Although the
potential.for exposure to contaminants through ingestion of cranberries exists,
contaminant concentrations in the ground and surface waters immediately
upgradient of the cranberry bog (southwest of Swamp 8) are below health-based
levels. In addition, contaminant levels within the plume have been decreasing with
time. Thus, this ACL demonstration only addresses potential exposure via pathways
that could lead to (a) human exposure by ingestion of water and ingestion of both
fish and water and (b) exposure of aquatic organisms in the wetland area.
2.3 Report Organization
This application is presented in eight sections: executive summary,
introduction, identification of ACL constituents, general information, geologic and
hydrologic information, exposure pathways, development of alternate
concentration limits, and ground-water monitoring program. The ACL criteria
listed in 40 CFR 264.94(b) are discussed within these eight sections. Appendix A
contains a cross-reference of the 19 ACL criteria to the applicable section in this
application. Appendix B provides the chemical and physical properties and
integrated risk information system (IRIS) data base information for toluene and
1,1,2-trichloroethane. Appendix C provides the typical wetland species for the
county in which Facility C is located.
2-4
-------
OSWER Di rective 9481.00-11
The discussion in these sections presumes a familiarity with information given
in the RCRA Part B permit application for this facility. This ACL application presents
the arguments for the ACL demonstration for this facility. Data that appear in the
Part B permit application are not reproduced in this document unless they were
deemed necessary for the sake of clarity and continuity.
2-5
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OSWER Directive 9481 00-11
3.0 IDENTIFICATION OF ACL CONSTITUENTS
3.1 Hazardous Constituents in the Waste
Accurate records were not maintained at the time that hazardous wastes were
deposited at the four closed units* The list of constituents suspected to be present
at this site has been developed from sampling and analysis of waste materials and
soils removed from the closed units. The wastes and much of the soil were placed in
the Nu-Cell. Analysis of wastes presently being placed in the Nu-Cell also
contributed to the list of constituents because these new wastes originate from the
same process as the old wastes. This information is presented in Table 3-1. A
detailed description of the sampling and analysis of the waste is presented in
Section C of the Part B permit application.
3.2 Extent and Degree of Contamination
At Facility C, toluene and 1,1,2-trichloroethane have been detected in the
ground water on-site and off-site and in the downgradient surface waters. No
hazardous constituents other than toluene and 1,1,2-trichloroethane have been
detected; consequently, only toluene and 1,1,2-trichloroethane are addressed in
this ACL application. The physical and chemical properties and health and
environmental risk information of these constituents are described in Appendix B.
A ground-water monitoring program was initiated at Facility C in 1978. At
that time, 11 detection ground-water monitoring wells were installed, MW-1
through MW-11 (Figure 3-1). Additional wells (MW-12 through MW-36) and five
surface-water monitoring stations (S-1 through S-5) were added in late 1980 as part
of a program to assess the nature and extent of the contaminant plumes.
Monitoring station S-5 is not shown in Figure 3-1 but is at the point where Swamp A
enters Pond A. Table 3-2 presents the maximum concentrations measured for the
period 1978-1986 for toluene and 1,1,2-trichloroethane, with the year in which each
occurred. Compliance monitoring wells for the Nu-Cell (CW-1 through CW-5) were
installed in 1985. The regulatory agency has agreed that contaminant
concentrations detected at Nu-Cell compliance wells are related to the closed cells.
3-1
-------
OSWER Directive 9481.00-11
TABLE 3-1.
HAZARDOUS CONSTITUENTS PRESENT IN WASTES
Category
Volatile
Aromatic
Hydrocarbons
Chlorinated
Volatile
Organics
Ketones
Acid
Extractable
Organics
Base/Neutral
Extractable
Organics
Others
Compound
Benzene
Toluene
Ethylbenzene
Xylenes
Chlorobenzene
1,2-Oichloroethane
1,1,1-Trichloroethane
1,1-Dichloroethane
1,1,2-Trichloroethane (TCA)
1,1,2,2-Tetrachloroethane
Chloroethane
Chloroethene
Chloroform
1 , 1 -Dichloroethylene
Trans-1,2-dichloroethylene
Methylene chloride
Fluorotrichloromethane
Tetrachloroethylene
Trichloroethylene (TCE)
Carbon tetrachloride
Acetone
Methyl ethyl ketone
Methyl isobutyl ketone
Phenol
2-Nitrophenol
2,4-Dimethyl phenol
Bis (2-chloroethyl) ether
1 ,2-dichlorobenzene
Nitrobenzene
Isophorone
Naphthalene
Bis(2-ethylhexyl) phthalate
Tetrahydrofuran
PCB-1242
3-2
-------
OSWER Directive 9481.00-11
LEGEND
Monitoring Wall (MW)
Compllwie* Well (CW & MW)
FIGURE 3-1. MONITORING AND COMPLIANCE WELL LOCATIONS
3-3
-------
OSWER Directive 9481.00-11
TABLE 3-2.
MAXIMUM CONCENTRATIONS (mg/l) OF TOLUENE AND
1,1,2-TRICHLOROETHANE DURING THE PERIOD 1978-1986
Sampling Point9
MW-1
MW-2
MW-3
MW-4
MW-5
MW-6
MW-7
MW-8
MW-9
MW-10
MW-11
MW-1 3
MW-1 4
MW-1 6
MW-1 7
MW-1 8
MW-1 9
MW-20
MW-21
MW-27
MW-28
MW-30
MW-31
MW-32
MW-33
CW-1
G/V-2
CW-3
CW-4
CW-5
5-1
S-2
S-3
S-5
Toluene
15.2
12.9
107.6
29.4
33.3
32.0
53.9
42.6
4.1
4.8
26.8
1.7
1.2
0.870
3.6
1.2
8.9
0.860
17.7
7.0
NO
0.670
6.1
3.8
0.680
1.1
0.787
1.1
0.666
1.1
3.8
2.9
0.150
0.031
Year
; 78
78
78
78
81
78
78
78
81
81
81
81
81
81
81
81
81
81
81
81
81
81
81
86
86
86
86
86
86
81
81
81
81
1 , 1 ,2-Triehloroethane
1 .8
10.9
9.2
13.2
8.1
6.2
11.4
11.1
3.8
0.366
13.9
0.109
0.018
0.103
0.047
0.230
0.082
0.085
0.877
2.4
0.009
NO
0.067
0.012
NO
0.032
0.060
0.090
0.025
0.016
0.024
0.015
0.010
NO
Year
79
79
79
79
81
79
79
79
79
79
81 .
81
81 -
81
81
81
81
81
81
81
81
81
81
86
86
86
86
86
81
81
81
81
Sampling points MW-12, MW-15, MW-22-26, MW-29, MW-34, MW-35 and MW-36are
omitted because the constituents were not detected (NO)
3-4
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OSWER Directive 9481.00-11
This has been inferred from the data since the Nu-Cell is downgradient of the
leaking closed cells and because the concentrations in the Nu-Cell wells are at levels
that would be expected to occur if the Nu-Cell was not present. The most recent
ground-water monitoring was conducted in the fourth quarter of 1986.
Wells on the downgradient perimeter of the closed cells have been designated
compliance monitoring wells. These include MW-1 through MW-4, MW-6, MW-7,
and MW-9 through MW-14 (Figure 3-1). Additional details on ground-water
monitoring at the POCare presented in Section F of the Part B permit application.
A summary of the interim status ground-water monitoring data and the
analysis for Appendix IX constituents are presented in Section E of the Part B permit
application. Section F of the application contains a description of the contaminant
plumes, including monitoring results and estimates of plume migration rates.
Table 3-3 presents concentrations of toluene and 1,1,2-trichloroethane for
1981 and 1986. Section E of the Part B application contains concentration data for
the entire monitoring period 1978-1986. Isopleths derived from Table 3-3 are
presented for toluene in Figure 3-2 (1981) and Figure 3-3 (1986). Isopleths derived
from Table 3-3 are presented on Figure 3-4 (1981) and Figure 3-5 (1986) for 1,1,2-
trichloroethane. Two important observations can be made from this table and the
figures: (a) between 1981 and 1986 the concentrations of both contaminants have
decreased; and (b) the contaminant plumes travel both northwest and southwest.
The toluene and 1,1,2-trichloroethane plumes have very similar shapes. Each
has a northwest and a southwest lobe. The southwest lobes are within the property
boundary and have migrated toward the bedrock spring; the northwest lobes have
migrated off-site toward Swamp A. The northwest lobes exhibit higher
concentrations than the southwest lobes apparently because most of the leakage
has occurred from the two westernmost closed cells in areas where the ground-
water flow direction is toward the northwest.
3-5
-------
OSWER Directive 9481.00-11
TABLE 3-3.
CONCENTRATIONS (mg/l) OF TOLUENE AND
1,1,2-TRICHLOROETHANEFOR 1981 and1986(a)
Sampling Point or
Monitoring Well
MW-KW
MW-2
MW-3
MW-4
MW-5
MW-6
MW-7
MW-8
MW-9
MW-10
MW-11
MW-12
MW-13
MW-14
MW-15
MW-16
MW-17
MW-18
MW-19
MW-20
MW-21
MW-22
MW-23
MW-24
MW-25
Toluene
1981J
3.9
4.1
4.6
10.1
33.3
17.2
20.1
5.3
.4.1
4.8.
26.8
ND +
1.7
1.2
NO
0.870
3.6
1.2
9.8
0.860
17.7
ND
ND
NO
ND
1986
1.6
1.6
1.7
3.2
10.1
6.5
7.2
3.0
2.5
2.8
8.8
ND
0.931
0.387
ND
0.147
0.520
0.350
4:6
0.185
6.7
ND
ND
ND
ND
1,1,2-Trichloroethane
1981
0.751
7.8
12.3
12.6
8.1
1.4
11.6
10.3
2.7
0.134
13.9
ND
0.109
0.018
ND
0.103
0.047
0.230
0.82
0.085
0.877
ND
ND
ND
ND
1986
1 376
3.3
3.8
2.63
3.4
0.456
3.7
3.6
1.639
0.017
3.9
ND
0.021
ND
ND
0.016
0.002
0.054
0.006
0.007
0.445
ND
ND
ND
ND
3-6
-------
OSW E R Di recti ve 9481.00-11
TABLE 3-3. (continued)
CONCENTRATIONS (mg/l) OF TOLUENE AND
1,1.2-TRICHLOROETHANE FOR 1981 and 1986(a)
Sampling Pointer
Monitoring Well
MW-26
MW-27
MW-28
MW-29
MW-30
MW-31
MW-32
MW-33
MW-34
MW-35
MW-36
Nu-cell Compliance
Wells
CW-1
CW-2
CW-3
CW-4
CW-5
Surface Water
S-1
S-2
S-3
S-4
S-5**
Toluene
19df
ND
7.0
1.8
ND
0.067
6.1
3.8
0.520
ND
ND
ND
NS*
NS
NS
NS
NS
3.8
2.9
0.150
ND +
0.031
1986
ND
3.6
0.083
ND
ND
0.264
0.116
0.080
ND
ND
ND
1-1
0.787
1.1
0.666
1.5
0.133
0.123
0.016
ND
ND
1 , 1 ,2-Tnchloroethane
1981
IMD
2.4
0.01
ND
ND
0.067
0.012
ND
ND
ND
ND
NS
NS
NS
NS
NS
0.024
0.015
0.010
ND
NO
1986
ND
1.2
ND
ND
ND
0.004
ND
ND
ND
ND
ND
0.032
0.060
0.090
0.025
0.016
ND
0.004
0.005
ND
ND
(a) For data of the years not listed in table, see Section E of Part B permit application.
(b) Monitoring wells MW-1 through MW-4, MW-6, MW-7, and MW-9 through MW-14 are compliance
wells for the closed cells
* IMS » Not sampled, because the sampling point did not exist
** Located at point of overflow from Swam p A to Pond A
>. ND » Not detected (less than 0.001 mg/l)
3-7
-------
OSWER Directive 9481.00-11
+ - . "".-*- y^3
0 Montorin« W*«l (MW)
Compliwa «•)! (CV» & MW)
FIGURE 3-2. ISOPLETHS FOR TOLUENE (mg/1)
BASED ON CONCENTRATIONS IN 1981
3-8
-------
OSWER Directi ve 9481.00-11
v'tiiiij
LEGEND
Monitoring Well (MW)
Compliance WalMCW & MW)
Surfaea Sampling (S)
FIGURE 3-3. ISOPLETHS FOR TOLUENE (mg/l)
BASED ON CONCENTRATIONS IN 1986
3-9
-------
OSWER Directive 9481.00-11
fii
LEGEND
0 Monitoring Wall (MW)
• Compliance Wall (CW & MW)
Surfaca Sampling (S)
^•« Concvntration tOadMd Whara Infarrad)
FIGURE 3-4. ISOPLETHS FOR 1,1,2-TRICHLOROETHANE (mg/l)
BASED ON CONCENTRATIONS IN 1981
3-10
-------
OSWER Directive 9481.00-11
mjj/l^Q Y~
-*:imiit/ I
MW-29 J)
®MW-34
L Swamp 8 -
®MW.23 LEGEND
0 Monitoring Wall (MW)
• Compliance Wall (CW & MW)
® Surfaca Sampling (S)
l^j OnpocalCall ^^
•^•- Coneamration (Oaihad Whara Infarrad) Scala, Ft«t
250 500
FIGURE 3-5. ISOPLETHS FOR 1,1,2-TRICHLOROETHANE (mg/l)
BASED ON CONCENTRATIONS IN 1986
3-11
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OSWER Directive 9431 00-n
4.0 GENERAL INFORMATION
4.1 Land Use
The facility is located in a rural marshland area in the northeast United States.
Most of the land within a mile of the facility is marshland or meadow. The
meadowland was formerly used'as pasture but now lies vacant and overgrown.
Twenty private residences are located within one mile of the facility; three of these
are within one-half mile of the facility. The nearest community lies approximately 1-
1/2 miles northeast. The one commercial/agricultural operation in the area is a
cranberry bog 1-1/4 miles southwest of the facility. Figure 4-1 shows the
topography, ponds, cranberry bog, and wetlands in the vicinity of Facility C.
4.2 Water Use and Users
The natural background quality of the ground water meets all Federal and
State drinking water standards. This ground water is the principal source of water
for the nearby residences. The State has certified that the ground water in the
region of Facility C is of beneficial use to the public. All residences-within one-half
mile of Facility C have private wells upgradient of the facility. The twenty wells
within one mile of the facility (designated R-1 through R-20) are shown in Figure 4-1
and described in further detail in Table 4-1.
The nearest open surface water body is Pond A, which is approximately one-
half mile west of Facility C (see Figure 4-1) and is used for sport fishing by local
residents. Water from Pond A is also used to irrigate a commercial cranberry
growing operation at the cranberry bog 1-1/4 miles southwest of the facility. Water
from Pond A is pumped to the bog at the typical rate of 100 gallons per minute
during harvest and periods of drought.
Pond B is approximately one mile southwest of Facility C (see Figure 4-1). Pond
B is larger and more accessible than Pond A and is used for swimming, boating,
fishing, and general recreational purposes. Pond B is connected to Pond A by a
narrow inlet. The nearby marshes (Swamps A and B) have no known direct use to
humans. However, they provide valuable habitat for various species of plants and
4-1
-------
OSWER Directive 9481.00-11
Oom«rticW«ll
FIGURE 4-1. TOPOGRAPHIC MAP AND OFF-SITE WELL LOCATIONS
4-2
-------
OSWER Directive 9481.00-11
TABLE 4-1.
INVENTORY OF WELLS WITHIN ONE MILE OF THE FACILITY
Well
R-1
R-2
R-3
R-4
R-5
R-6
R-7
R-8
R-9
R-10
R-11
R-12
R-13
R-14
R-1 5
R-16
R-17
R-18
R-19
R-20
Ground
Elevation
(ft)
495
496
500
505
568
583
588
582
528
542
548
549
555
528
524
532 .
535
524
525
532
Well
Depth
/ (ft)
29
30
34
45
60
78
86
88
35
43
47
52
61
45
39
51
49
45
50
61
Depth to
Water
(ft)
9
10
16
20
45
65
67
65
20
27
31
30
39
23
25
28
26
29
27
42
Use
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Domestic
Pump
Capacity
(gpm)
10
10
10
20
20
10
10
10
10
10
10
20
10
10
10
10
20
10
20
10
4-3
-------
OSWER Directive 9481.00-11
animals. Indirectly the swamps benefit humans by improving water quality in the
ponds and by providing nesting areas for some of the sport fishes in the ponds.
4.3
Precipitation
Thirty years of precipitatiorfdata are available from a meteorological station
nine miles northeast of the facility. The average annual precipitation is 42.6 inches
with precipitation patterns varying relatively little from month to month. The
average monthly precipitation is shown in Table 4-2.
TABLE 4-2.
MONTHLY PRECIPITATION*
Month
January
February
March
April
May
June
July
August
September
October
November
December
Year
Average
Precipitation
(inches)
4.03
3.76
4.05
3.86
3.35
2.70
2.85
3.96
3.44
3.00
4.03
3.57
42.60
Source: NOAA, 1986
*Based on 30 years of records.
4-4
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OSWER Directive 9481.00-1 1
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION
Facility C is in glaciated terrain in the northeastern United States. The local
topography is characterized by small hills interspersed with marshland. Figures 5-1
and 5-2 show the location of the facility on a hill overlooking two swamps.
Constituents that have leaked from the facility have been observed to migrate
northwest toward Swamp A and southwest toward Swamp B.
This section of the ACL demonstration summarizes the information on
regional and site geology and hydrology pertinent to this ACL application. The
geology and hydrology of the facility are described in detail in Sections D, E, and F
of the Part B permit application.
5.1 Regional Geology
Surficial deposits in the site area are unconsolidated materials of Pleistocene
and Recent age, which discontinuously mantle an irregular bedrock surface.
Pleistocene deposits are glacial in origin. Recent deposits, being less abundant,
consist of stream and river alluvium, swamp deposits, and talus. During the
Pleistocene, the advancing ice sheet scoured away preglacial soils and regolith,
eroding considerable quantities of bedrock as well. This debris was incorporated
into and transported by the glacial ice. Deposition took place either directly, as
lodgement till beneath the advancing ice, or later, as ablation till during glacial
». *
retreat. The latter materials were often reworked by meltwater streams near the
front of the ice sheet. Postglacial deposits (Recent in age) are typically strips of
alluvial silt, sand, and gravel, which line stream beds. Talus slopes are well
developed at the base of cliffs where frost action and chemical weathering have
loosened weak materials from higher elevation. Swamp deposits are typically
composed of organic debris, silt, and fine sand. Located in topographic basins, the
swamp deposits may include layers of impure peat.
Bedrock is predominately granitic gneiss, consisting primarily of orthoclase
feldspar, quartz and biotite mica. Other rock types are present regionally in minor
amounts. Rock ages range from Precambrian to Pennsylvanian. The granitic
gneiss, which dominates the quadrangle and the site area, exhibits strong foliation.
5-1
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OSWER Directive 9481.00-11
FIGURE 5-1. REGIONAL TOPOGRAPHY
5-2
-------
OSWER Directive 9481.00-11
.490
500
510
520
490
500
530
Northeast
Oispotal
C«ll 540
*&°
LEGEND
® Monitoring Well (MW)
Surface EUvation Contour, Fwt (MSL)
100 200 300
=55
Scale, Feet
FIGURE5-2. SITE TOPOGRAPHY
5-3
-------
OSWER Directive 9481.00-11
This foliation generally strikes northward and dips westward, the same as bedding
structures in the other rock units. Locally, shear zones cross the foliation. In these
zones, rocks are typically finer grained. No major faults have been mapped in the
vicinity of Facility C (Section B of the Part B application).
5.2 Site Geology
The site is on a hill composed of a thick glacial deposit with many surface
boulders (some reaching 5 to 8 feet in diameter). Many of the granitic gneiss
cobbles and boulders exposed in pits near the site exhibit chemical weathering
along joints and between feldspar and biotite grains. Borings indicate that the
glacial deposit may exceed 40 feet in thickness beneath the facility, decreasing to
approximately 20 feet near Swamp A. Boring logs presented in Appendix II of the
Part B permit application also indicate many washed zones within the till, composed
principally of sand and gravel. These zones of internal stratification are clearly
exposed just northeast of the disposal site. The high percentages of sand and gravel
encountered in the boreholes and exposures indicate a sandy ablation till overlies
most of the bedrock at the site. Bedrock is exposed southwest of the Nu-Cell.
Swamp A consists of Recent-age organic and lacustrine deposits, and is
underlain by the same sandy, ablation till. Till in the vicinity of Swamp B consists of
a thin veneer of Recent-age organic deposits overlying bedrock. Bedrock springs,
such as the spring near the southwest corner of the facility, are typical of areas
where this veneer is not present.
Two geological cross sections were prepared using boring logs compiled from
field investigations. The orientation of these cross sections is shown in Figure 5-3.
The southwest-northeast section A-A' (Figure 5-4) runs from BRW-2, just southwest
of the disposal site, to MW-24. This section shows the subsurface adjacent to the
disposal areas and generally perpendicular to ground-water flow. Borings MW-28
and MW-24 at the north end of the section do not show the abundance of boulders
described in logs to the south. This absence of boulders may be indicative of
outwash from the ablation till to the south. However, a gravel pit 100 feet south of
MW-28 exhibits many cobbles and large boulders.
5-4
-------
OSWER Directive 9481 00-11
LEGEND
O Monitoring Wttl (MW)
Boring (ORW)
FIGURE 5-3. LOCATION OF CROSS SECTIONS
5-5
-------
EUvation From
Arbitrary
Bench Mark
Projected
W««t Call
cn
i
01
IW-9 /
MW-!
Section B-B- /Projected NWC.II
r-60
i;£-'i.£ .•-•^•'•-
-------
OSWER Directive 9481.00-11
Section B-B' (Figure 5-5) is roughly perpendicular to A-A' and provides a
subsurface cross section along a ground-water flow line typical of the northwest
lobe. The section transects the north end of the west disposal cell. A predominance
of sand and gravel in borings at the west end of section B-B' suggests deposition of
washed material at lower elevations. Localized pockets of fine sand and gravel
appear in borings higher on the hill.
Fractured bedrock beneath the site has been recorded in several borings. A
core obtained from boring BRW-1 shows fractures between 45 and 74 feet below
ground surface with an associated Rock Quality Designation (RQD) of 23 to 45
percent. A core from boring BRW-2 shows weathered gneiss extending from ten to
44 feet below the ground surface with associated RQD values of 30 to 55 percent.
At depth, fracturing becomes less frequent, and the degree of weathering of the
gneissic bedrock decreases.
5,3 Ground-Water Hydrology
Ground water beneath the site flows in two hydraulically-connected, water-
bearing formations. The upper portion of the aquifer consists of unconsolidated,
sandy glacial till and swamp deposits. The lower portion consists of approximately
30 feet of fractured bedrock. Hydraulic conductivities for the unconsolidated
deposits range from 3.2 x 10-4 to 3.5 x 10*3 cm/sec. Similar values of hydraulic
conductivity were observed within the fractured gneiss, ranging between 2.1 x 10-4
to 3.2 x 10-3 cm/sec. Vertical movement of water from one formation to the other is
governed by localized differences in conductivity between till and bedrock, and by
differences in potentiometric head.
In the upland area of the disposal site, potentiometric surface elevations from
wells screened in bedrock are slightly lower than elevations measured in adjacent
overburden wells. This difference indicates a downward component of flow,
consequently the disposal site represents an area of ground-water recharge. For
lowland areas, the vertical gradient is reversed, demonstrating that ground water
5-7
-------
OSWER Oi recti ve 9481 00-11
Elevation From
Arbitrary
Banch Mark
B
MW-
Section A-A
NW
EOB
EOS
LEGEND
«m Topsoil
••••9KEB1
'W$,
'/'•':••':'• -1' •'•'.
Note: Till
Silt
Sand & Gravel
Shown is Typical!
>-:::::::::::i:£:
:•:•:•:•:•:•:•'.•»:
V '•
• ' .;».-
M-C Sand & Gravel
Cobbles
8i?SI Bould">
»>&'•
#&
Ws
y a Combination
Till
Granitic Gneiss
Granitic Gneiss
With Fractures
Contact (Dashed Where Inferred)
R- Refusal
EOB — End of Boring
?— Inferred Sand Lens or
Bedrock Topography
0 200 40(
(In Oacraasing Amounti) of Sand, Graval
Cobbles, Boulders and Silt
Seal*., Foet
FIGURE 5-5. CROSS SECTION B-B'
5-8
-------
OSWER Directive 9481 00-H
discharges into the wetland areas. This scenario is typical of the glaciated terrain in
the northeast. In the vicinity of Swamp B, there is only a thin veneer of till overlying
the bedrock, resulting in areas of ground-water discharge from the bedrock such as
the bedrock spring noted in Figure 5-1.
Data obtained from the monitoring well network at the site (Table 5-1) were
used to develop a water table contour map (Figure 5-6). The upland area
immediately west of the site between Swamp A and Swamp B (see Figure 5-1) is
believed to act as a ground-water divide due to its higher elevation and relatively
low permeability (1.5 x 10-5 cm/sec). Because of the site's location on a convex hill
slope, and the presence of a ground-water divide through the disposal area,
contaminants introduced at the site have been observed to migrate as two lobes,
one to the northwest, the other to the southwest (compare Figures 3-2 and 3-3 with
Figure 5-6). The flow directions dictated by the local and regional divides remain
throughout the seasons. Changes in water level during the months of June,
September, and December (see Part B permit application) were minor fluctuations
and about the same magnitude in all wells.
The bedrock boring log for MW-36 indicates minimal weathering/fracturing at
depth for the area west of Swamp A. Seismic profiles indicate that the water table
surface follows the bedrock topography. The northernmost seismic data points in
the western profile show a higher water table in the western bedrock outcrop than
at Swamp A. This implies ground-water flow toward Swamp A.
Most of the ground water that flows from the site originates as recharge from
precipitation. Much of the site represents an upland area where the regional
ground-water flow contribution is limited.
The aquifer properties of principal interest are hydraulic gradient, hydraulic
conductivity, effective porosity, and dispersivity. Table 5-2 summarizes these
properties. The results of field and laboratory tests to determine these parameters
are described in detail in the Part B permit application, Section D.
5-9
-------
OSWER Directive 9481.00-11
TABLE 5-1.
GROUND-WATER ELEVATIONS (1984)
Well
MW-3
MW-4
MW-5
MW-6
MW-9
MW-10
MW-13
MW-15
MW-16
MW-17
MW-19
MW-20
MW-21
MW-22
MW-23
MW-24
MW-25
MW-26
MW-28
MW-29
MW-31
MW-34
MW-35
MW-36
June
Elevation
(ft) ;
497.4'
495.7
496.0
500.1
497.5
502.7
498.3
502.5
482.9
488.7
489.8
490.3
490.1
465.0
467.7
491.4
503.0
487.1
495.1
517.6
478.5
449.4
478.8
478.7
September
Elevation
(ft)
497.6
495.9
496.2
500.3
497.7
502.9
498.5
502.7
483.1
488.9
490.0
490.5
490.4
465.2
467.9
491.6
503.2
487.3
495.3
517.8
478.7
449.6
479.1
478.9
December
Elevation
(ft)
497.8
496.1
496.4
500.5
497.9
503.1
498.7
502.9
483.3
489.1
490.2
490.7
490.6
465.4
468.1
491.8
503.4
487.5
495.5
518.0
478.9
449.8
479.3
479.2
5-10
-------
OSWER Directive 9481.00-11
— j- Swamp A ...
— _—— 480
LEGEND
0 Monitoring Well (MW
• Compliance W«»l (CW & MW)
Surfica Sampling (S)
OltpoalC**)
•*— Qround-wrattr Flow
—- El«v«tion IDariMd WlMra Mtrrwl)
®MW-zj I
Water Surface Elevation
FIGURE 5-6. WATER TABLE CONTOURS (Feet Above MSL)
5-11
-------
OSWER Directive 9481.00-11
TABLE 5-2.
AVERAGE PROPERTIES OF THE UPPERMOST AQUIFER
Property
Hydrostratigraphy
Depth to Water Table
Horizontal Gradient
Vertical Gradient
Hydraulic Conductivity
Unconsolidated Deposits
Bedrock
Porosity
Dispersivity
Longitudinal
Transverse
Description/Value
Glacial deposits with sand and gravel
zones; granitic gneiss bedrock
10 to 40 ft
0.0 144 ft/ft
0.076 ft/ft
3.2 x 10-4 to 3.5 x 10-3 cm/sec
2.1 x 1 0-4 to 3. 2 x 10-3 cm/sec
0.10to0.25
208ft
53ft
5.3.1 Hydraulic Conductivity
Hydraulic conductivity values were obtained in the laboratory by analysis of
grain-size distributions of samples obtained during borehole drilling operations of
wells MW-3, MW-5, MW-8, MW-9, MW-15, MW-19 and MW-21. In situ hydraulic
conductivity was determined by two pump tests and seven slug tests. Aquifer pump
tests were performed at wells BRW-1 and BRW-2 while monitoring wells MW-19,
MW-21 and MW-16 were observed. Seven slug tests were conducted at the
following wells: bedrock wells MW-25, MW-27, and MW-28; and overburden/till
wells MW-5, MW-15, MW-21 and MW-31. Table 5-3 presents these data.
Conductivity values generally range within one order of magnitude in the two
major water-bearing formations.
5.3.2 Effective Porosity
Effective porosity of an aquifer material corresponds to the specific yield of an
aquifer under unconfined conditions. The specific yield was determined from the
pump testsat wells BRW-1 and BRW-2. The values, interpreted from drawdown/
5-12
-------
OSWER Directive 9481.00-11
TABLE 5-3.
ESTIMATED HYDRAULIC CONDUCTIVITIES OF THE UPPERMOST AQUIFER
Method of Analysis
Grain-size Distribution
MW-8
MW-9
MW-19
MW-3
MW-5
MW-15
MW-21
Aquifer Pump Test
BRW-ia
BRW-2a
MW-16
MW-21
MW-19
MW-10
AquiferSlugTestb
MW27a
MW-5
MW-15
MW-25
MW-28
MW-21
MW-31
Hydraulic Conductivity
ft/day
•
0.8
5.0
7.7
10.0
7.6
3.8
6.9
8.2
9.1
0.9
5.4
9.7
0.042
0.6
3.4
2.2
4.9
4.7
3.9
3.7
cm/sec
2.8x 10-4
1.8x 10-3
2.7x10-3
3.5x10-3
2.7x10-3
1.3x10-3
2.4x10-3
2.9x10-3
3.2 x 10-3
3.2 x 10-4
1.9x10-3
3.4 x 10-3
1.5x10-5
2.1 x 10-4
1.2x10-3
7.8x10-4
1.7x10-3
1.7x10-3
1.4x10-3
1.3x10-3
Bedrock wells.
Average values.
5-13
-------
OSWER Directive 9481.00-11
recovery data at nearby observation wells, were 0.25 (MW-19 and MW-21) and
0.10 (MW-16). The test at well BRW-1 stressed primarily overburden, thus affecting
MW-19 and MW-21. The test at BRW-2 stressed primarily bedrock, affecting MW-
16. The resulting calculated values were consistent with published ranges for
fractured gneiss and unconsolidated sand and gravel.
5.3.3 Oispersivity
A chloride tracer study was performed at the site and is documented in Section
D of the Part B permit application. Data obtained from the tracer study provides
calculated dispersivities of 208 feet (longitudinal) and 53 feet (transverse).
These values are within published ranges for sites of similar scale and aquifer
characteristics (Freeze and Cherry, 1979).
5.4 Surface Water Hydrology
Surface water runoff from the facility flows either northwest toward Swamp A
or southwest toward Swamp B. The majority of the surface water runoff discharges
into Swamp A. Swamp A is less than 100 feet from the northwest corner of Facility C
(see Figure 5-1). Water entering Swamp A flows to Pond A and into the cranberry
bog. Other sources of recharge to Pond A include ground-water discharge (i.e.,
springs) and direct precipitation.
A much smaller amount of site surface runoff discharges into Swamp B, which
is approximately one-half mile southwest of Facility C (see Figure 5-1). Swamp B
discharges into Pond B, which also receives water from Pond A, springs, and
precipitation.
5-14
-------
05WER Directive 9481.00-11
6.0 EXPOSURE PATHWAYS
Contaminants leaching from Facility C will generally follow the fate and
transport paths outlined in Figure 6-1. The northwest lobe of contamination flows
toward Swamp A, toward Pond A, and toward the cranberry bog while being
diminished by a variety of physical, chemical, and biological mechanisms. The
southwest lobe of contamination" flows toward the bedrock spring but has not
reached Swamp B. Exposure to contaminants released from the facility may occur at
various points along these paths, but, due to attenuation of the plume, the critical
points of exposure will tend to be closer to the source.
This analysis of potential exposures to the hazardous constituents considers
both human and environmental receptors. No current human exposures to
contaminants from this facility have been identified, but humans could be exposed
to the contaminants through contact with ground or surface waters, or via a
contaminated food chain. Ecosystems in the swamps, ponds, or cranberry bog are
ail potential contaminant receptors.
6.1 Potential Human Exposure
6.1.1 Exposure to Contaminated Drinking Water
The northwest contaminant plume extends offsite beyond the northern
facility property boundary. At this time, there are no supply wells intercepting
contaminated ground water emanating from the site. However, there are no local
or state laws to prevent a person from drilling a well into the contaminated ground
water. Therefore, for the inactive units, the human point of exposure (POE) from
drinking water will be a hypothetical well completed in the uppermost aquifer
along the northern facility property boundary.
Because there is no evidence of leakage of hazardous constituents into the
ground water from the Nu-Cell, the POE for drinking water for the Nu-Cell will be
assumed to be at the point of compliance (POC) along the Nu-Cell boundary (EPA,
1987a).
6-1
-------
OSWER Directive 9481.00-]]
NORTHEAST
CELL
ADSORPTION
ONTO SOIL
BIODEGRADATION
DISCHARGE TO
SWAMP A
SURFACE WATER
VOLATILIZATION TO
AMBIENT AIR
NORTHWEST
CELL
NORTHWEST
GROUND-WATER*
LOBE
DISCHARGE TO
POND A
WEST
CELL
ADSORPTION
ONTO SOIL
BIODEGRADATION
CRANBERRY
BOG
SOUTHWEST
GROUND-WATER
LOBE
SOUTH
CELL
BEDROCK
SPRING
VOLATILIZATION TO
AMBIENT AIR
FIGURE 6-1. FLOW DIAGRAM OF POLLUTANT MIGRATION PATHWAYS/FATE
6-2
-------
OSWER Directive 9481 30-P
6.1.2 Exposure to Contaminated Food Chain
Potential exposure to contaminants through the ingestion of contaminated
surface water and/or aquatic organisms could occur based on the uses of the
surrounding surface waters. As previously stated, both Pond A and Pond B are used
for recreational purposes, including sport fishing. Surface water is not used as a
local water supply for domestic purposes. Although the potential for exposure to
contaminants through ingestion of cranberries exists, the cranberry bog is not
receiving contaminated irrigation water, and contaminant levels within the plume
have been decreasing with time. The concentrations of contaminants in the ground
water discharging into Swamp A and Pond A are below allowable human health
exposure criteria.
6.2 Potential Environmental Exposure
Three environments were initially considered for risk of exposure: the
swamps, the ponds, and the cranberry bog. Sampling data (shown in the Part B
permit application, Section F) reveal that the cranberry crop is not at risk of
exposure to contaminants from this site for several reasons. Contaminants from the
site are discharged only into Swamp A where they are volatilized, biodegraded, and
adsorbed onto peat. Very small amounts of contaminants were detected in 1981 at
the inlet to Pond A from Swamp A (sampling point S-5 in Table 3-3). Those
contaminants are further degraded, diluted, and volatilized in the pond water.
Contaminants from the site have not and are not expected to reach the cranberry
crop at the south side of Pond A. No contaminants have been detected in Swamp B
or Pond B. A study of the surrounding area indicates that there are no other likely
contamination sources for the surface waters except Facility C.
Assessment of hydrogeologic data available for the site indicates that ground
water from the site is discharging into Swamp A, Swamp B, and the bedrock spring.
The swamps contain plant and animal organisms that may be adversely affected by
site contaminants. Although no detailed ecological data have been gathered on
the biota of Swamp A, it is possible to identify species known to occur in nearby
marsh areas. This information, provided in Appendix C, may be useful in tracing
- *
possible pathways of exposure and was supplied by the U.S. Fish and Wildlife
Service. The data are extracted from the New England Animal Species Data Base for
6-3
-------
OSWER Directive 9481.00-11
the county in which the site is located. Three distinct habitat types are given: (1)
emergent wetland (Table C-1); (2) scrub/shrub wetland (Table C-2); and (3) forested
wetland (Table C-3). Aerial photographs of the site show swamp maple and other
trees. There is no reported evidence of vegetative stress within the site boundary or
in the surrounding wetland areas that can be attributed to toluene and 1,1,2-
trichloroethane contamination of gVound water and surface water.
6.2.1 Endangered Species
No endangered species have been identified in the vicinity of Facility C, and
none are suspected to inhabit the area. The U.S. Fish and Wildlife Service has
provided a letter to this effect that is included in the Part B permit application.
6.3 Maximum Allowable Exposure Concentrations
The critical exposure pathways identified above include: (a) human ingestipn
of water; (b) combined human ingestion of aquatic organisms and water; and (c)
ecosystem exposure. Allowable exposure concentrations are calculated below for
each of these pathways.
Ingestion of contaminated water could pose a significant health risk because
both toluene and 1,1,2-trichloroethane have been recognized by the EPA to be
systemic toxicants. The U.S. EPA has also classified 1,1,2-trichloroethane as a
possible human carcinogen (Class C, based on (ARC criteria; EPA, 1987b).
Allowable exposure levels (C in equations 6-1 and 6-2) for ingestion of these
constituents have been calculated based on (a) the oral reference doses (RfDs) of 0.3
mg/kg/day for toluene and 0.2 mg/kg/day for 1,1,2-trichloroethane and (b) a risk
level (R) of 10-5 and the carcinogenic potency factor, or slope factor (PF), of 0.057
(mg/kg/dayH for 1,1,2-trichloroethane, a possible carcinogen (Class C). A risk level
of 10-5 was used because EPA ranks 1,1,2-trichloroethane as only a Class C
carcinogen and because there is no current use of ground water downgradient of
the facility. The other values were obtained from the Integrated Risk Information
System (IRIS) data base developed by EPA (1987b). Appendix B of this
demonstration contains the information obtained from IRIS on these constituents.
6-4
-------
OSWER Directive 9481 00-1
The exposure levels for the ingestion of water contaminated with toluene and
1, 1,2-trichloroethane are calculated (and reported in Table 6-1) using equations 6-1
and 6-2 and assuming an ingestion rate of 2 liters of water per day by a 70 kg adult
(EPA, 1987a). Equation 6-1 applies to the reference dose (RfD) methodology,
whereas equation 6-2 applies to the risk specific dose (RSD; carcinogenic)
methodology:
CRfo = RfD x W
(6-1)
Iw
CRSD = R xW (6-2)
IwxPF
where:
C = Exposure level developed by either the RfD or RSD method, mg/l;
R s Risk level, usually ranging from 10-* to 10-7;
RfD = Reference Dose, mg/kg/day;
W = Weight of an average adult, kg (assumed to be 70 kg);
Iw = Water intake by the average adult, I/day (assumed to be 2 I/day);
PF = Carcinogenic potency factor, or slope factor, (mg/kg/day)-i.
Similarly, the allowable exposure levels (C) associated with the ingestion of
both aquatic organisms and water contaminated with toluene and 1,1,2-
trichloroethane are calculated (and reported in Table 6-1) using equations 6-3 and
6-4, with an assumed ingestion rate of 2 liters of water per day by a 70 kg adult
(EPA, 1987a). These equations were modified from those used for water alone by
adding a term to account for the ingestion of contaminated aquatic organisms. For
this demonstration, it is assumed that the average adult ingests 0.0065 kg of fish per
day and that toluene and 1,1,2-trichloroethane have bioconcentration factors
(BCFs) of 10.7 I/kg and 5 I/kg, respectively (EPA, 1986b).
6-5
-------
TABLE 6-1.
ALLOWABLE EXPOSURE LEVELS
Chemical & CAS
No.
Toluene
108 88-3
1,1,2-
Trichloroethane
79-00-5
MCLH1
NA
NA
RfDUl
0.3
0.2
PF131
—
0.057
Human Exposures (mg/!)
Drinking
Water
(Eq. 6-1 & 6-2)
10.5(4]
7.0(4]
0.006(5]
Drinking Water and
Fish Ingestion
(Eq. 6-3 & 6-4)
10.2(4]
6.9(4]
0.006(5]
Ecosystem
Exposures
(mg/l)(6l
Acute
17.5
9.4
Chronic
0.175
9.4 '
Maximum Allowable
Exposure
Concentration!?]
(mg/l)
0.175
0.006
i .
a\
Notes:
[ 1 ] Maximum Contaminant Level, expressed in ug/l when available. NA = not available.
[2] Reference Dose, expressed in mg/kg/day.
[3] Carcinogenic Potency Factor, expressed in (mg/kg/day)-1.
[4] Based on Reference Dose (RfD) method.
[5] Based on Risk-Specific Dose (RSD) method.
[6] Based on Water Quality Criteria for 1986 (EPA, 1986a).
[7] Most protective exposure level tabulated for the specific hazardous constituent.
o
i/»
m
y»
O
s
3
n
I
o
o
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OSWER Directive 9481.00-11
C'Rfo - RfDxW
:(6-3)
Iw + (0.0065 xBCF)
C'RSD = R xW •
PFx[lw + (0.0065 x BCF)] (6"4)
Exposure levels for ingestion of fish only may be calculated by deleting the
water ingestion term (Iw) in equations 6-3 and 6-4.
The EPA freshwater quality criteria for acute and chronic ecosystem exposure
to the two hazardous constituents are also considered in determining the maximum
allowable exposure concentrations for use in setting ACLs. As noted in Appendix B
and in a 1986 EPA publication (EPA, 1986a), no acute or chronic aquatic freshwater
ecosystem criteria have been established for toluene or 1,1,2-trichloroethane.
However, the acute lowest effect level (LEL) for toluene is 17.5 mg/l and the chronic
LELfor 1,1,2-trichloroethane is 9.4 mg/l.
In the absence of chronic exposure data, EPA (1985; Box 3.4) suggests that
chronic exposure criteria be estimated from the acute criteria by using an acute to
chronic ratio (ACR) of 10 and a species sensitivity uncertainty factor of 10. Following
this procedure, the criteria for chronic exposure of aquatic organisms to toluene is
estimated to be 0.175 mg/l. For 1,1,2-trichloroethane, the acute exposure criteria
for aquatic organisms was established at the chronic LEL; this is a conservative
approach. Thus, 9.4 mg/1 will serve here as both the estimated acute and chronic
criteria for 1,1,2-trichloroethane (Table 6-1).
Table 6-1 presents the exposure levels for each of the hazardous constituents
using equations 6-1 through 6-4 and the acute and chronic aquatic ecosystem
exposure criteria discussed in the preceding paragraph. The most protective
exposure levels were then selected as the maximum allowable exposure
concentrations at the POE.
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OSWER Directive 9481 00-1
7.0
DEVELOPMENT OF ACLs
The proposed ACLs for Facility C are based on human ingestion of fish and
water for 1,1,2-trichloroethane and on chronic ecosystem exposure for toluene.
These ACLs are presented in Table 7-1. Because toluene and 1,1,2-trichloroethane
produce different types of adverse effects, dose additivity is not considered.
TABLE 7-1.
PROPOSED ALTERNATE CONCENTRATION LIMITS
Constituent
Toluene
1 ,1 ,2-Trichloroethane
Point of
Exposure
Facility boundary
Facility boundary
Maximum
Allowable
Concentrations
(ug/0
175
6
Proposed
ACL
(ug/D
175
6
a From Table 6-1
Note that since the northern disposal cells are immediately upgradient of the
property boundary, the POE (facility boundary) and the POC are essentially the
same. Therefore, the maximum allowable exposure concentrations are proposed as
the ACLs. Maximum allowable exposure levels for the Nu-Cell are the same as for
the four closed cells; therefore, the ACLs will also be the same.
The current levels of toluene and 1,1,2-trichloroethane (Tables 3-2 and 3-3)
exceed the proposed ACLs. Due to noncompliance for these constituents, a
corrective action program has been proposed in the Part 8 permit application
(Section J).
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OSWER Directive 9481.00-11
8.0 GROUND-WATER MONITORING
Analytical results of ground-water samples obtained from site monitoring
wells indicate that constituents are degrading in situ. Tables 3-2 and 3-3 show that
the concentrations are decreasing with time. The contaminant plume maps
(isopleths) presented in Section 3^how a decrease in the size of both plumes from
1981 to 1986. Further monitoring of the ground water is necessary to determine the
future effectiveness of this in situ degradation. Furthermore, Facility C is examining
the efficacy of in situ biodegradation as a method of corrective action.
8.1 Compliance Monitoring
The compliance monitoring system for the site is described in Sections F and I
of the Part B permit application. The monitoring system will include several of the
present monitoring wells due to their downgradient proximity to the closed land
disposal units. Figure 3-1 shows the locations of wells in the proposed compliance
monitoring system. Wells serving as compliance point monitoring wells for the Nu-
Cell disposal cell will be compliance wells CW-1 through CW-5 and monitoring well
MW-18. Monitoring wellsMW-13 and MW-14 will serve as compliance wells for the
south disposal cell. For the western disposal cell, MW-1, MW-9, MW-2, and MW-3
are the compliance wells. For the northwest and northeast disposal cells, MW-4,
MW-7, MW-11, MW-6, and MW-10 will be the compliance wells.
Compliance wells for the Nu-Cell will be monitored semi-annually for the
detection parameter specified in the permit application. All other compliance wells
will be monitored quarterly for toluene and 1,1,2-trichloroethane and annually for
Appendix IX constituents. Off-site monitoring wells and surface water sampling
locations (including on-site S-3) will be sampled at least annually. Additional
monitoring will be done, if needed, during the corrective action process to make
sure the process is working.
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OSWER Directive 9481.00-11
REFERENCES
Freeze, R.A. and J.A. Cherry, 1979. Groundwater. Prentice-Hall, Inc., Englewood
Cliffs, NJ.
EPA (U.S. Environmental Protectioh Agency), 1985. Technical Support Document for
Water Quality-based Toxics Control. EPA/440-4-85-032, Office of Water,
Washington, D.C., September.
EPA (U.S. Environmental Protection Agency), 1986a. Quality Criteria for Water,
1986, EPA/440-5-86-001, Washington, D.C., May 1.
EPA (U.S. Environmental Protection Agency), 19866. Superfund Public Health
Evaluation Manual. EPA 540/1-86/060. Washington. D.C.. October.
EPA (U.S. Environmental Protection Agency), 1987a. Alternate Concentration Limit
Guidance, Part 1. Policy and Information Requirements, Interim Final, OSWER,
EPA/530-SW-87-017, Washington, D.C.July.
EPA (U.S. Environmental Protection Agency), 1987b. Integrated Risk Information
System. Supportive Documentation. Vol. I, EPA/600-8-86-032a, Washington,
D.C., March.
NOAA (National Oceanic and Atmospheric Administration), 1986. Local
Climatoloqical Data. Annual Summaries for 1985. Parti.
Other Resource Documents
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December, 1979.
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OSWER Directive 9481.00-11
APPENDIX A
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
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OSWER Directive 9481 00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
Criteria for Assessing Potential Adverse Effects on ._. r c ,
Ground-Water Quality: fiSinn Jn V
§264.94(b)(1) Section No.
(i) The physical and chemical characteristics of the 3.1,3.2
waste in the regulated unit, including its
potential for migration;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3
facility and surrounding land;
(iii) The quantity of ground water and the direction 5.3
of ground-water flow;
(iv) The proximity and withdrawal rates of ground- 4.2
water users;
(v) The current and future uses of ground water in 4.1,4.2
the area;
(vi) The existing quality of ground water, including 3.2
other sources of contamination and their
cumulative impact on the ground-water
quality;
(vii) The potential for health risks caused by human 6.1, 6.3
exposure to waste constituents;
(viii) The potential damage to wildlife, crops, 6.2, 6.3
vegetation, and physical structures caused by
exposure to waste constituents;
(ix) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects;
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OSWER Directive 9481.00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
(Continued)
Criteria for Assessing Potential Adverse Effects on Af, - ctud\/
Hydraulically-Connected Surface-Water Quality: ?«rtirm Nn
§264.94(b)(2) . seccion NO.
(i) The volume and physical and chemical 3.1,3.2
characteristics of the waste in the regulated
unit;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3,5.4
facility and surrounding land;
(iii) The quantity and quality of ground water, and 5.3,5.4
the direction of ground-water flow;
(iv) The patterns of rainfall in the region; 4.3
(v) The proximity of the regulated unit to surface 4.2
waters;
(vi) The current and future uses of surface waters in 4.1,4.2
the area and any water quality standards
established for those surface waters;
(vii) The existing quality of surface water, including 3.2
other sources of contamination and the
cumulative impact on surface water quality;
(viii) The potential for health risks caused by human 6.1, 6.3
exposure to waste constituents;
(ix) The potential damage to wildlife, crops, 6.2,6.3
vegetation, and physical structures caused by
exposure to waste constituents; and
(x) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects.
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OSWER Directive 9481 00-11
APPENDIX B
CHEMICAL AND PHYSICAL PROPERTIES1 AND IRIS
(INTEGRATED RISK INFORMATION SYSTEM)
DATA BASE FOR TOLUENE AND
1,1,2-TRICHLOROETHANE
1 Adapted from: Chemical, Physical and Biological Properties of Compounds Present
at Hazardous Waste Sites. Office of Waste Programs Enforcement (OWPE) and
Office of Solid Waste and Emergency Response (OSWER), U.S. EPA, Final Report,
September 1985.
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OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
TOLUENE
108-88-3
0.3 mgkg/day
CAS Number:
RfD:
Chemical Formula:
IDPACName: Methylbenzene
Important Synonyms and Trade Names: Toluol, phenylmethane, methylbenzene
Chemical and Physical Properties
Molecular Weight:
Boiling Point:
Melting Point:
Specific Gravity:
Solubility in Water:
Solubility in Organics:
Vapor Pressure:
Vapor Density:
Viscosity:
Flash Point:
92.13
110.6°C
-95°C ~
0.8669 at 20°C
534.8 mg/liter
Soluble in acetone, ligroin, and carbon disulfide;
miscible with alcohol, ether, benzene, chloroform,
glacial acetic acid, and other organic solvents
28.7mmHgat25°C
3.14
0.625 centipoise at 15.6°C
4.4°C
Log Octanol/Water Partition Coefficient: 2.69
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Toluene; CAS No. 108-88-3 (Revised 11/16/1986)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic toxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Toluene :
I. Chronic Systemic Toxicity: Noncarcinogenic Health Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: none
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481 00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical' Toluene
CAS No.: 108-88-3 / Preparation Date: 01/08/86
1. REFERENCE DOSE SUMMARYTABLE
Critical Effect Experimental Doses * UF MF RfD
Clinical chemistry 300 ppm (1130 mg/cu. 100 1 3E-1
and hematological m) converted to 29 mg/kg/day
parameters mg/kg/day (NOAEL)
Rat chronic inha- LOAEL: None f
lation study
CUT (1980)
* Dose Conversion Factors & Assumptions: 5 days/7 days, 6 hour/24 hour;
0.5 absorption factor, 20 cu. m human breathing rate; 70 kg; thus, 1130
mg/cu. mx5day/7daysx6hours/24hoursx0.5x20cu. m/cTay/70 kg =
28.8 mg/kg/day
2. PRINCIPAL AND SUPPORTING STUDIES
CUT (Chemical Industry Institute of Toxicology). 1980. A 24-month inhalation
toxicology study in Fischer-344 rats exposed to atmospheric toluene. CUT, Research
Triangle Park, NC.
Toluene is most likely a potential source of respiratory hazard. The only
chronictoxicity study on toluene was conducted for 24 months in male and female
F344 rats (CUT, 1980). Toluene was administered by inhalation at 30,100 or 300
ppm (113, 377 or 1130 mg/cu. m)to 120 male and 120 female F344 rats for 6
hours/day, 5 days/week. The same number of animals (120 males and 120 females)
was used as a control. Clinical chemistry, hematology and urinalysis testing was
conducted at 18 and 24 months. All parameters measured at the termination of the
study were normal except for a dose-related reduction in hematocrit values in
females exposed to 100 and 300 ppm toluene.
Based on these findings, a NOAEL of 300 ppm or 1130 mg/cu. m was derived.
An oral RfD of 20 mg/day can be derived using route-to-route extrapolation. This
was done by expanding the exposure from 6 hours/day, 5 days/week to continuous
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OSWER Directive 9481.00-11
exposure and multiplying by 20 cu. m/day and 0.5 to reflect a 50% absorption
factor.
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 100. An uncertainty factor of 100 (10 for sensitive individuals and 10 for
intraspecies extrapolation was also applied.
MF = 1
4. ADDITIONAL COMMENTS
The only oral study found in the data base (Wolf et al., 1956) contains
subchronicdata in which no adverse effects of toluene were reported at the highest
dose tested (590 mg/kg/day).
5. CONFIDENCE IN THE RfD
Study: High Data Base: Medium RfD: Medium
Confidence in the critical study is high because a large number of animals/sex
were tested in each of three dose groups and many-para meters were studied.
Interim kills were performed. The data base is rated medium because several
studies support the chosen effect level. The confidence of the RfD is not higher than
medium because the critical study was by the inhalation route.
6. DOCUMENTATION AND REVIEW
Limited Peer Review and Agency-wide Internal Review, 1984.
U.S. EPA. 1985. Drinking Water Criteria Document for Toluene. Office of
Drinking Water, Washington, DC.
Agency RfD Work Group Review: 05/20/85,08/05/85,08/05/86
Verification Date: 05/20/85
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OSWER Directive 9481 00-11
7. U.S. EPA CONTACTS
Primary: C.T. DeRosa FTS/684-7534 or 513/569-7534
Office of Research and Development
Secondary: M.L. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Toluene
CAS No.: 108-88-3
This chemical has not been evaluated by the U.S. EPA for evidence of human
carcinogenic potential.
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical: Toluene
CAS No.: 108-88-3 Preparation Date: 09/30/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
B-6
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OSWE R Oirecti ve 9481.00-11
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
A. RISK MANAGEMENT ACTIONS
Risk
Management
Action
Reportable
Quantity (RQ)
Water Quality
Criteria (WQC):
a. Human Health
b. Aquatic Toxicity
1) Freshwater
Status
Date
Final
1985
Final
1980
Final
1980
Risk
Management
Value
1000 I bs
14.3 mg/l
Acute
1 7,500 ug/l (LEL)
Considers
Econ/Tech
Feasibility
no
no
no
Reference
50 FR 13456
04/04/85
45 FR 793 18
11/28/80
ibid.
2) Marine
Clean Air Act
Regulatory
Decision:
(NESHAPorNSPS)
Final
1980
Final
1984
Chronic
none
Acute no
6,300 ug/l (LEL)
Chronic
5,000 ug/l (LEL)
Decision not no
to Regulate
ibid.
49 FR 22195
05/25/84
B. RISK MANAGEMENT RATIONALE
RQ
The final RQ is based on aquatic toxicity, as established under Section 311 (b)(4)
of the Clean Water Act, ignitabiiity and chronic toxicity. Available data indicate
that the aquatic 96-Hour Median Threshold Limit for Toluene is between 10 and 100
ppm. Its dosed cap flash point is less than 100 degrees F and its boiling point is
greater than 100 degrees F. RQ assignments based on chronic toxicity reflect two
primary attributes of the hazardous substance, the minimum effective dose (MED)
levels for chronic exposure (mg/day for 70-kg man) and the type of effect (liver
necrosis, teratogenicity, etc). In accordance with the methodology described in the
Agency's "Technical Background Document to Support Rulemaking Pursuant to
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OSWER Directive 9481 00-1
CERCLA Section 102, Volume 1" of March 1985 and 50 FR 13468 (04/04/85), a
composite score is determined from an evaluation of these two attributes. Toluene
was determined to have a composite score between 6 and 20, corresponding to a
chronic toxicity RQ of 1000 pounds.
Contact: RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
WQC
Contact: Office of Water Regulations and Standards
202-382-5400 or FTS-382-5400
a. Human health: The WQC of 14.3 mg/l is based on consumption of
contaminated aquatic organisms and water. A WQC of 424 mg/l has also been
established based on consumption of contaminated aquatic organisms alone.
b. Aquatic toxicity: Water quality criteria for the protection of aquatic life are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The "(LEL)" after the value indicates that the minimum data were not
available and the concentration given is not a criteria value but the lowest effect
level found in the literature.
CAA Regulatory Decision
EPA concluded that current information does not indicate that toluene
endangers public health at ambient concentrations (excluding emergency releases),
and thus no regulation directed specifically at toluene is necessary at this time
under the CAA.
Contact: Chief, Pollutant Assessment Branch
FTS/629-5645 or 919/541-5645
V. SUPPLEMENTARY DATA
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
Synonyms: ANTISALIa, METHYL-BENZENE, METHACIDE, PHENYL-METHANE,
METHYLBENZENE, METHYLBENZOL, NCI-C07272, PHENYLMETHANE, RCRA WASTE
NUMBER U220.TOLUEEN (Dutch), TOLUEN (Czech), TOLUENE, TOLUOL, TOLUOLO
(Italian), TOLU-SOL, UN 1294
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OSWER Directive 9481.00-11
RESOURCE DOCUMENTS FOR TOLUENE
American Conference of Governmental Industrial Hygienists, Documentation
of the Threshold Limit Values. 4th ed.. Cincinnati, Ohio, 488 pp., 1980
McCoy and Associates, "Physical/Cnemical Data Compendium for Common
Solvents," The Hazardous Waste Consultant. Vol. 4, No. 6, Nov./Dec, 1986, pp.
4-1 to 4-32.
National Institute for Occupational Safety and Health, Criteria for a Recommended
Standard-Occupational Exposure to Toluene. DHEW Publication No. (NIOSH)
HSM73-11023, Washington, D.C., 1983.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base. Washington. D.C.. October 1983. ;
National Research Council, The Alky! Benzenes. National Academy Press,
Washington, D.C., 1980.
Sax, N. I., Dangerous Properties of Industrial Materials. 4th ed.. Van Nostrand
ReinholdCo.,NewYork, 1975,1,258pp.
U.S. Environmental Protection Agency. Ambient Water Quality Criteria for Toluene,
EPA/440-5-80-075. Office of Water Regulations and Standards, Criteria and
Standards Division, Washington, D.C., October, 1980.
U.S. Environmental Protection Agency, Health Effects Assessment for Toluene. Final
Draft, ECAO-CIN-HO-03, Environmental Criteria and Assessment Office,
Cincinnati, Ohio, September 1984.
U.S. Environmental Protection Agency, Water-RelatedEnvironmental Fate of 129
Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December 1979.
Weast, R. E., ed., Handbook of Chemistry and Physics. 62nd ed, CRC Press,
Cleveland, Ohio, 1981,2,332 pp.
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OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
1,1,2-TRICHLORETHANE
Summary
CAS Number: 79-00-5
Chemical Formula: CH2CICHCl2
IDPACName: 1,1,2*Trichloroethane
Important Synonyms and Trade Names: Vinyl trichloride, ethane trichloride
Chemical and Physical Properties
Molecular Weight: 133.41
Boiling Point: 133.8°C
Melting Point: -36.5°C
Specific Gravity: 1.4397 at 20°C
Solubility in Water: 4,5000 mg/liter at 20°C
Solubility in Qrganics: Soluble in alcohol, ether, and chloroform
Log Octanol/Water Partition Coefficient: 2.17
Vapor Pressure: 19 mm Hg at 20°C
Vapor Density: 4.63
FlashPoint: Not Flammable
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS):Chemical Files
1,1,2-Trichloroethane; CAS No. 79-00-5 (Revised 09/30/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive reviewof chronic tbxicity data by work groups composed of U.S. EPA
scientists from several Agency Prdgram Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. Foe a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4. /
STATUS OF DATA FOR 1,1,2-Trichloroethane
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Regulatory Actions: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: 1,1,2-Trichloroethane
CASNo.: 79-00-5 , Preparation Date: 12/05/85
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Organ histopathology NOEL: 92 mg/kg/day 300 1 2E-1
(adjusted to 65.7 mg/kg/day
RatSubchronicto mg/kg/day for
Chronic Gavage Study treatment schedule)
NCI, 1978 LOAEL: none f
* Dose Conversion Factors & Assumptions: Treatment schedule « 5 days/week
2. PRINCIPAL AND SUPPORTING STUDIES
NCI (National Cancer Institute). 1978. Bioassayof 1,1,2-trichloroethane for possible
carcinogenicity. U.S. DHEWTech. Rep. Ser. 74. Publ. No. NIH 78-1324.
Osborne-Mendel rats (50/sex/group) were administered 1,1,2-trichloroethane
by corn oil gavage 5 days/week at dose levels of 46 and 92 mg/kg/day for 78 weeks.
Both untreated and vehicle.controls were employed (20/sex/group). Extensive
histopathology was performed after 78 weeks. No treatment-related non-
neoplastic lesions were observed. A mouse oncogenicbioassay was also conducted,
with no noncarcinogenic effects observed at doses of 195 and 390 mg/kg/day.
An unpublished inhalation study with several species (Dow Chemical Co.)
showed unspecified fatty changes for female rats at 164 mg/cu.m after 3 weeks of
exposure. No effects were observed at an exposure level of 82 mg/cu.m for 7
hours/day, 5 days/week for 6 months. Equivalent oral doselevels were about 6 and
12 mg/kg/day. The effects seen cannot be judged as to adversity.
The NCI (1978) rat study NOEL is more appropriate as a basis for the RfD than
the mouse NOEL because higher doses have not been administered to rats, and the
inhalation studies suggest that the rat may be more sensitive than other species to
the effects of this compound.
B-12
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05WER Directive 9481.00-11
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 300. The UF includes the standard uncertainty factors for interspecies and
intrahuman variability and a factor of 3 for extrapolation to lifetime exposure from
an intermediate exposure duration.
MF = 1
4. ADDITIONAL COMMENTS
None.
5. CONFIDENCE IN THE RfD
Study: Medium Data Base: Low RfD: Low i
The critical study is given a medium confidence for balanced strengths
(histopathology) and weaknesses (lack of other parameters). The supporting data
base is meager. The RfD is rated low because of the general lack of appropriate
toxicologicdata.
6. DOCUMENTATION AND REVIEW
The RfD is not currently documented elsewhere, but the studies discussed are
reviewed in: U.S. EPA. 1980. Ambient Water Quality Criteria for Chlorinated
Ethanes. Prepared by the Office of Health and Environmental Assessment,
Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of
Water Regulations and Standards, Washington, DC. EPA 440/5-80-029. NTIS PB 81-
117400.
Agency RfD Work Group Review: 12/18/85,05/15/86
Verification Date: 12/18/85
7. U.S. EPA CONTACTS
Primary: M.L. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
Secondary: C.T. DeRosa FTS/684-7534 or 513/569-7534
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OSWER Directive 9481.00-11
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5 Preparation Date: 02/18/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification:C, possible human carcinogen, based on hepatocellular carcinomas
and pheochromocytomas in one strain of mice. Carcinogenicity was not shown- in
rats. Structurally related to 1,2-dichloroethane, a probame human carcinogen.
1. HUM AN DATA
None.
2. ANIMAL DATA
In a bioassay conducted by NCI (1978) technical grade (92.7% pure) 1,1,2-
trichloroethane was given in corn oil to 50 each male and female Osborne-Mendel
rats and B6C3F1 mice. Administration was 5 times/week for 78 weeks during which
time doses for rats were increased from 70 and 30 mg/kg/day to 100 and 50
mg/kg/day; doses for mice were increased from 300 and! 50 mg/kg/day to 400 and
200 mg/kg/day. By two statistical tests, treatment of mice was found to be
associated with increased incidence of hepatocellular carcinomas. A dose-related
increase in pheochromocytomas was also confirmed in female mice. Tumors found
in treated but not control rats included adrenal cortical carcinomas, transitional-cell
carcinomas of kidney, renal tubular adenomas and hemangiosarcomas of spleen,
pancreas, abdomen and subcutaneous tissue. There was, however, no statistically
significant increase in incidence as a function of treatment.
3. SUPPORTING DATA
1,1,2-Trichloroethane was found to be nonmutagenic for Salmonella
typhimurium (Simmon etal., 1977). In rats and mice acutely exposed to 1,1,2-
trichloroethane by inhalation andlntraperitoneal injection, trichloroacetic acid,
trichloroethanol, chloroacetic acid and thiodiacetic acid were among the urinary
metabolites identified (Yllner, 1971; Ikeda and Ohtsuji, 1972). 1,1,2-
Trichloroethane is structurally related to 1,2-dichloroethane, a probable human
carcinogen.
8-14
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OSWER Directive 9481.00-11
B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 5.7E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE -
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/L)
6E1 ug/L 6 ug/L 6E-1 ug/L 1.6E-6 LM, extra
risk
2. DOSE-RESPONSE DATA
Species/Strain Administered Tumor Reference
Tumor Type Dose Human Equivalent Incidence
Mouse/B6C3F1, Route: Oral, gavage
male; hepato-
cellular carcinoma mg/kg/day mg/kg/day
0 0 2/20 NCI, 1978
139 9.3 18/49
279 18.6 37/49
3. ADDITIONAL COMMENTS
Doses are TWAs adjusted for frequency of exposure (5/7 days). Weight of the
mice was assumed to be 0.033 kg.
The unit risk should not be used if the water concentration-exceeds 6E + 3 ug/L,
since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE ESTIMATE
Dose-related increases in hepatocellular carcinomas were observed in
adequate numbers of mice of both sexes. Modeling was done on only one data set.
Background incidence of this tumor type is generally high. Confidence in the risk
estimate is rated low to medium.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
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OSWER Directive 9481.00-11
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
C. INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 5.7E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
6ug/cu.m 6E-1 ug/cu.m 6E-2 ug/cu.m 1.6E-5 LM, extra
risk
2. DOSE-RESPONSE DATA
The inhalation risk estimates were calculated from the oral exposure data.
3. ADDITIONAL COMMENTS
The unit risk should not be used if the air concentration exceeds 6E + 2
ug/cu.m, since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
Confidence in this inhalation risk estimate based on oral data is rated low.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
D. DOCUMENTATION AND REVIEW
1. REFERENCES
NCI (National Cancer Institute). 1978. Bioassay of 1,1,2,-Trichloroethane for
Possible Carcinogenicity. U.S. Dept. Health, Educ. Welf. Pub. No. NCl-CG-TR-74.
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OSWER Directive 9481.00-11
U S. EPA. 1980. Ambient Water Quality Criteria for Chlorinated Ethanes. Prepared
by the Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Cincinnati, OH for the Office of Water Regulations and
Standards Washington, DC. EPA 440/5-80-029. NTIS PB 81117400.
2. REVIEW:
The values in the Ambient Water Quality Criteria Document for Chlorinated
Ethanes received extensive peer and public review.
Agency Work Group Review: 07/23/86
Verification Date: 07/23/86
3. U.S. EPA CONTACTS
Primary: C Hiremath 202/382-5725 or FTS/382-5725
Office of Research and Development
Secondary: R.E. McGaughy 202/382-5898 or FTS/382-5898
III. DRINKING WATER HEALTH ADVISORIES
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5
Information is not available at this time.
IV. REGULATORY ACTIONS
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5 Preparation Date: 09/30/87
INTERPRETATION OF REGULATORY ACTION INFORMATION
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Regulatory actions are frequently not
updated at the same time. Carefully read the dates for the regulatory actions (in
this section) and the verification dates for the risk assessments(in sections I & II), as
this may explain apparent inconsistencies. Also note that some regulatory actions
consider factors not related to health risk, such as technical or economic feasibility.
Such considerations are indicated for each action following (Econ/Tech Feasibility
entry). In addition, not all of the regulatory actions listed in this section involve
enforceable federal standards. Please direct any questions you may have
concerning the use of risk assessment information in making a regulatory decision
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OSWER Directive 9481.00-11
to the U.S. EPA contact listed for that particular regulatory action. Users are
strongly urged to read the background information on each regulatory action in
Appendix D in Service Code 4.
A. AIR
Information is not available at this time.
B. WATER
Information is not available at this time.
C TOXICS/ PESTICIDES
Information is not available at this time.
D. SUPERFUND / RESOURCE CONSERVATION AND RECOVERY ACT (RCRA)
REPORTABLE QUANTITY (RQ); for Release into the Environment
Value (status) -- 100 pounds (Proposed, 1987)
Considers technological or economic feasibility? -- NO
Discussion -- The proposed RQfor 1,1,2-trichloroethane is 100 pounds, based on
potential carcinogenicity. The available data indicate a hazard ranking of "low,"
based on a potency factor of 0.36 (mg/kg/day)-1 and weight-of-evidence group "C,"
which corresponds to an RQ of 1 00 pounds.
Reference --
U.S. EPA Contact -- RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
========
V. SUPPLEMENTARY DATA
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5
Information is not available at this time.
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OSWER Directive 9481.00-11
SYNONYMS: ETHANE, 1,1 2-TRICHLORO-; ETHANE TRICHLORIDE; NCI-C04579;
RCRA WASTE NUMBER U227- RCRA WASTE NUMBER U359; beta-T; beta-
TRICHLOROETHANE; 1,1,2-TRICHLORETHANE; 1,1,2-TRICHLOROETHANE; 1,2,2-
TRICHLOROETHANE; 1,1,2-TRICHLOROETHANE (ACGIH); TROJCHLOROETAN(1,1,2)
(Polish); VINYL TRICHLORIDE
8-19
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OSWER Directive 9481.00-11
RESOURCE DOCUMENTS FOR 1,1,2-TRICHLOROETHANE
National Cancer Institute, Bioassay of 1,1,2-Trichloroethane for Possible
Carcinoqenicity. NCI Carcinogenesis Technical Report Series No. 74,
DHEW Publication No. (NIH) 78-1324,1977
U.S. Environmental Protection Agency, Research and Development.Verified
Reference Doses (RfDs) of the U.S. EPA, ECAO-CIN-475, Environmental Criteria
and Assessment Office, Cincinnati, Ohio, January, 1986.
International Agency for Research on Cancer, "Some Halogenated Hydrocarbons,"
IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to
Humans. Vol. 20, World Health Organization, Lyon, France, 1979, pp. 545-572.
National Institute for Occupational Safety and Health (NIOSH), Registry of Toxic ?
Effects of Chemical Substances-Data Base, Washington, D.C., October, 1983.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Chlorinated Ethanes. EPA/440-5-80-029, Office of Water Regulations and
Standands, Criteria and Standards Division, Washington, D.C., October, 1980.
U.S. Environmental Protection Agency, Health Assessment Document for
Dichloromethane (Methylene Chloride). EPA/600-8-82-004F, Office of Health
and Environmental Assessment, Washington, D.C.,. February, 1985.
U.S. Environmental Protection Agency, Health Effects Assessment for 1.1,2-
Trichloroethane. ECAO-CIN-HO-045, Environmental Criteria and Assessment
Office, Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December, 1979.
Verschueren, K., Handbook of Environmental Data on Organic Chemicals, Van
Nostrand Reinhold Co., New York, 1977, 656 pp.
8-20
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OSWER Directive 9481.00-11
Weast, R. E., ed., Handbook of Chemistry and Physics. 62nd ed.. CRC Press,
Cleveland, Ohio, 1981, 2,332 pp.
B-21
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OSWER Directive 9481.00-11
APPENDIX C
TYPICAL WETLAND SPECIES FOR
COUNTY IN WHICH SITE C IS LOCATED1
1 Provided by the U.S. Fish and Wildlife Service.
C-1
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TABLE C-1.
TYPICAL SPECIES IN A PALUSTRINE (MARSHY), EMERGENT WETLAND
NJ
Plants
Herbivores
Omnivores
Carnivores
Cattail
Arrowhead
Rushes
Burweed
American Widgeon
Canada Goose
Beaver
Insects
Song Sparrow
Swamp Sparrow
Spotted Turtle
Wood Turtle
Mallard
King Rail
Virginia Rail
Sora
American Woodcock
Red-Winged Blackbird
Short-Tailed Shrew
White-Footed Mouse
Meadow Vole
Southern Bog Lemming
Meadow Jumping Mouse
Black Duck
Common Grackle
Star-Nosed Mole
Muskrat
Mute Swan
Belted Kingfisher
Common Snapping Turtle
Northern Spring Peeper
Common Yellowthroat
Pickeral Frog
Northern Black Racer
Eastern Smooth Green Snake
Black-Crowned Night Heron
Sedge Wren ••:,,
Marsh Wren
Water Shrew
Red Spotted Newt
Green Frog
Great Egret
Green-Backed Heron
American Bittern
Bullfrog
Stinkpot
m
O
I
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TABLE C-2.
TYPICAL SPECIES IN A PALUSTRINE, SCRUB/SHRUB WETLAND
n
i
U)
Plants
Herbivores
Omnivores
Carnivores
Alder
Button Bush
Myrica
Willows
Eastern Cottontail
New England Cottontail
White-Tailed Deer
Carolina Wren
Veery
White-Eyed Vireo
Yellow Warbler
Rose-Breasted Grosbeak
Eastern Bluebird
Yellow-Billed Cuckoo
Yellow-Breasted Chat
Song Sparrow
American Goldfinch
Racoon
Wood Turtle
Eastern Box Turtle
Marsh Hawk
American Woodcock
Red Winged Blackbird
Short-Tailed Shrew
White-Footed Mouse
Meadow Vole
Meadow Jumping Mouse
Black Duck
Common Snipe
Gray Catbird
Common Crackle
Blue Grey Gnatcatcher
Yellow Throated Vireo
Nashville Warbler
American Redstart
Long-Tailed Weasel
Northern Spring Peeper
Common Yelfowthroat
Swamp Sparrow
Northern Brown Snake
Eastern Ribbon Snake
Northern Black Racer
Eastern Smooth Green Snake
Eastern Milksnake
Black Crowned Night Heron
Cooper's Hawk
Water Shrew
Eastern Garter Snake
Red-Tailed Hawk
Canada Warbler
Henslow's Sparrow
Green Frog
Mink
River Otter
Bullfrog
Green Frog
a
m
3D
O
I
&
O
O
-------
TABLE C-3.
TYPICAL SPECIES IN A PALUSTRINE. FORESTED WETLAND
Plants
Herbivores
Omnivores
Carnivores
Red Maple
Elm
Ash
Swamp-White Oak
Swamp Oak
Eastern Cottontail Red-Headed Woodpecker
New England Cottontail Great Crested Flycatcher
White-Tailed Deer Black-Capped Chickadee
Tufted Titmouse
Veery
Cedar Waxwing
Scarlet Tanager
Brown Creeper
Wood Thrush
Scarlet Tanager
Wood Turtle
Eastern Box Turtle
Mallard
Marsh Hawk
Virginia Opossum
Meadow Vole
Grey Fox
Wood Duck
Black Duck
Mallard
Belted Kingfisher
Eastern Wood Pewee
Blue Grey Gnatcatcher
Nashville Warbler
Silver Haired Bat
Eastern Pipistrelle
House Wren,
Four-Toed Salamander
Wood Frog
Northern Brown Snake
Northern Redbelly Snake
Eastern Ribbon Snake
Eastern Hognose Snake
Eastern Worm Snake
Northern Black Racer
Eastern Smooth Green Snake
Eastern Milk Snake
Cooper's Hawk
Red Shouldered Hawk
Barred Owl
Long-Eared Owl
Water Shrew
Northern Spring Peeper
Fowler's Toad
Timber Rattlesnake
Wood Thrush
O
eft
m
30
O
i
o
9
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OSWER Directive 9481.00-11
ACL
CASE STUDY 3b
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OSWER DiRECT VE 9481
PREFACE
Case Study 3b is a hypothetical example of an acceptable ACL demonstration.
This case study was developed from actual site reports prepared with the assistance
of the U.S. Department of Energy (DOE) and submitted to the U.S. Nuclear
Regulatory Commission (NRC) pursuant to 40 CFR Part 192. Some information
presented in the site reports has been changed to create a more suitable case study.
in
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OSWER Directive 9481 00-r
CONTENTS
SECTION PAGE
1.0 EXECUTIVE SUMMARY 1-1
2.0 INTRODUCTION ' 2-1
2.1 FACILITY DESCRIPTION 2-2
2.2 APPROACH TO ACL DETERMINATION 2-2
2.3 REPORT ORGANIZATION 2-4
3.0 IDENTIFICATION OF ACL CONSTITUENTS 3-1
3.1 HAZARDOUS CONSTITUENTS IN THE WASTE 3-1
3.2 EXTENT AND DEGREE OF CONTAMINATION 3-1
4.0 GENERAL INFORMATION 4-1
4.1 LAND USE 4-1
4.2 WATER USE AND USERS 4-1
4.3 PRECIPITATION 4-4
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION 5-1
5.1 REGIONAL GEOLOGY 5-1
5.2 SITE GEOLOGY 5-1
5.3 GROUND-WATER HYDROLOGY 5-3
5.4 SURFACE WATER HYDROLOGY 5-11
6.0 EXPOSURE PATHWAYS 6-1
6.1 POTENTIAL HUMAN EXPOSURE 6-1
6.2 POTENTIAL ENVIRONMENTAL EXPOSURE 6-2
6.3 MAXIMUM ALLOWABLE EXPOSURE CONCENTRATIONS 6-4
7.0 DEVELOPMENT OF ACLs 7-1
IV
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OSWER Directive 9481 3C-
CONTENTS (continued)
REFERENCES R-1
r
*. •
APPENDICES
A LOCATION OF INFORMATION IN THE CASE STUDY A-1
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
B GENERAL INFORMATION AND HAZARDOUS B-1
CHARACTERISTICS OF MOLYBDENUM
AND IRIS (INTEGRATED RISK INFORMATION
SYSTEM) DATA BASE FOR URANIUM
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OSW53 Directive 9481 CO-
TABLES
NUMBER PAGE
3-1 Common Uranium Mill Tailings Contaminants 3-1
t
3-2 Maximum Observed Concentrations of ACL Constituents 3-4
3-3 Maximum Observed Concentrations of Other Constituents 3-6
and Parameters
4-1 Inventory of Wells Within One Mile of the Facility 4-3
4-2 Monthly Precipitation 4-5
5-1 Aquifer Parameters 5-7
6-1 Allowable Exposure Levels 6-6
7-1 Proposed Alternate Concentration Limits 7--1
VI
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OSWER Directive 948' 30-'
FIGURES
NUMBER PAGE
2-1 Site Layout of Facility E 2-3
3-1 Monitoring and Compliance Well Locations of Facility E 3-2
3-2 Isoplethsfor Molybdenum at Facility E 3-7
3-3 Isopleths for Uranium at Facility E 3-8
4-1 Land Uses and Private Well Locations 4-2
5-1 Site Location 5-2
5-2 Location of Geologic Cross Sections 5-4
5-3 Geologic Cross Section A-C 5-5
5-4 Geologic Cross Section B-C 5-6
5-5 Generalized Flow Direction Within the Unconfined Aquifer 5-8
5-6 Potentiometric Surface in Deep Confined Aquifer 5-10
VII
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OSWER Directive 9481 00-11
1.0 EXECUTIVE SUMMARY
Case Study 3b is an example of an ACL application submitted by Facility E for
alternate concentration limits .XACLs) under 40 CFR 264.94(b) and 40 CFR
192.32(a)(2). This case study illustrates the approach outlined in Case 3 of Part I of
the ACL Guidance Document (EPA, 1987) as it might apply to a dosed disposal unit.
Part I states that for units located over useable ground water, if the leading edge of
the plume extends off the facility property, the point of exposure (POE) will be
assumed to be no farther from the Point of Compliance (POC) than the facility
property boundary. At no time may the designated POE be beyond the original
facility boundary. Because the disposal unit at Facility E has been closed, no
attenuation is accounted for between the POC and the property boundary.
The facility is located in a semi-arid area near the Rocky Mountains. The area
surrounding the facility is sparsely populated. A city of 15,000 inhabitants is 2 miles
from the facility. Ground water is present in confined and unconfined aquifers
beneath the facility. Ground water from confined aquifers is the principal source of
water for drinking, agricultural, and industrial uses.
Four hazardous constituents have been detected in the ground water at the
facility: uranium, radium (-226 and -228), gross alpha particle radiation, and
molybdenum. As uranium mill tailings, these constituents are regulated under 40
CFR 192.32(a)(2). Under these regulations, uranium and molybdenum are added to
the list of hazardous constituents in 40 CFR 264.93, and the radioactivity limits for
radium and gross alpha (listing in Part 192, Sub part 0 Table A) are added to Table 1
of 40 CFR 264.94. Ground-water contamination by uranium and molybdenum
extends beyond the facility boundary. Ground water contaminated with uranium is
discharging to surface waters.
Human and ecosystem exposure pathways are discussed and evaluated in this
application. It is concluded that there is a potential for human exposure from
contamination of wells in the unconfined aquifer and from contamination of River
8. There is also the potential for aquatic exposure to contaminants in River B.
State and Federal maximum allowable concentration levels are compared for
each hazardous constituent. Proposed ACLs for uranium and molybdenum are
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OSWER Directive 9481.00-1:
based on the lowest of their maximum allowable concentration levels. ACLs are not
requested for gross alpha and radium. The concentration limits for gross alpha and
radium will beset at the values in Table A of 40 CFR192.32.
A Corrective Action Plan is being prepared for the facility because
concentrations of uranium and rtfolybdenum are above the proposed ACLs at the
POC and at points downgradient of the POC.
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OSWER Directive 9481 00-11
2.0 INTRODUCTION
This document is an example application by Facility E for alternate
concentration limits (ACLs) under 40 CFR 264.94(b) for two contaminants, uranium
and molybdenum, which have been detected in the ground water near the facility.
The facility is regulated by the JU.S. Nuclear Regulatory Commission (NRC). This
demonstration has been prepared based on the requirements of 40 CFR 192.32,
Standards for the Management of Uranium Byproduct Materials, and in accordance
with the U.S. Environmental Protection Agency's ACL Guidance Document (EPA,
1987). Under 40 CFR 192.32(a)(2)(vi), ACLs at uranium mill tailing facilities can only
be approved if they are (1) protective of human health and the environment and (2)
as low as reasonably achievable (ALARA) considering practicable corrective actions.
This case study focuses primarily on the determination of protection of human
health and environment. The ALARA determination is not considered in this case
example.
Two additional contaminants have been detected in the ground water:
radium (-226 and -228) and gross alpha particle radiation. ACLs are not being
proposed for these contaminants because, under 40 CFR 192.32 (a)(2)(ii),
radioactivity limits have been established for radium and gross alpha. These values
are listed in Table A of Subpart D, Part 192 and added to Table 1 of 40 CFR 264.94.
Concentration limits for radium and gross alpha will be set at the values in Table A
of 40 CFR 192.32.
Part I of the ACL Guidance Document establishes five cases for reviewing ACL
demonstrations. This case study meets the conditions of Case 3 because Facility E is
located over useable ground water and the plume extends off the facility property.
The point of exposure (POE) will be assumed to be no farther from the point of
compliance (POC) than the facility property boundary. Fate and transport
arguments may then be applied to ground-water contamination between the POC
and the POE at the facility boundary, assuming there is no possible route of
exposure on the facility property. At no time may the POE be beyond the original
facility boundary. Because the waste pile (described below) has been closed,
attenuation (i.e., fate and transport) factors will not be considered in deriving the
proposed ACLs.
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OSWER Directive 9481.00-11
2.1 Facility Description
Facility E is located in arid to semi-arid rangeland near the eastern slope of the
Rocky Mountains, The facility includes a closed uranium mill tailings waste pile that
covers roughly 80 acres of a 185-acre site. Figure 2-1 shows the site layout with
manufacturing facilities in the nprthwest corner of the facility property and the
waste pile in the middle of the property. The waste pile has been capped to reduce
the infiltration of precipitation. The closure system and measures include:
• A 6-foot-thick compacted earthen cover overlain by 1 to 2 feet of crushed
rock (to prevent erosion and intrusion by burrowing animals);
• A 30-foot-wide riprap apron around the base to protect against flooding
and river meander;
• A security fence around the facility; and
• Runoff control via a drainage ditch surrounding the riprap apron.
2.2 Approach to ACL Determination
Contaminants have leached from the site into the unconfined aquifer, forming
a plume that discharges to River B 1000 feet downgradient of the facility boundary.
Use of the unconfined aquifer is currently limited to some agricultural purposes,
although in the past the unconfined aquifer was used as a drinking water source.
Most agricultural water and all drinking water is pumped from deeper, confined
aquifers. Contaminant migration to the deeper aquifers has not occurred.
The basis for this ACL application is a demonstration that: (a) there is limited
potential for human exposure due to pumping from the unconfined aquifer and (b)
surface water concentrations at or beyond the point of discharge to the river are
within state and federal drinking water and wildlife standards and the
contaminants have not causeu statistically significant increases in surface water
concentrations. The ACL for uranium is based on carcinogenic effects and the ACL
for molybdenum is based on the EPA systemic toxicant effects, considering standard
assumptions for oral exposure.
2-2
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FIGURE 2-1. SITE LAYOUT OF FACILITY E
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OSWER Directive 9481.00-11
2.3 Report Organization
This application is presented in seven sections: executive summary,
introduction, identification of ACL constituents, general information, geologic and
hydrologic information, exposure^ pathways, and development of ACLs.
The discussion in these sections presumes a familiarity with information in the
U.S. Department of Energy (DOE) reports for this facility. Data that appear in these
reports are not reproduced in this document unless they were deemed necessary for
the sake of clarity and continuity. The discussion also assumes a familiarity with
EPA's ACL Guidance Document on information required in ACL demonstrations.
2-4
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OSWER Directive 9481 00-1
3.0
3.1
IDENTIFICATION OF ACL CONSTITUENTS
Hazardous Constituents in the Waste
The waste pile at the facility consists solely of uranium mill tailings.
Contaminants commonly associated with uranium mill tailings are listed in Table
3-1, some of which are not specifically listed in Appendix VIII of 40 CFR Part 261.
However, uranium mill tailings standards have been promulgated by EPA (1983)
that specify ground-water standards for several additional constituents, including
uranium and molybdenum. The chemical, physical, and biologic characteristics of
uranium and molybdenum are discussed in Appendix B.
TABLE 3-1.
COMMON URANIUM MILL TAILINGS CONTAMINANTS
Uranium
Thorium
Radium-226and -228
Radon-220 and -222
Lead-210
Other short-lived daughters
in the U-238 series
Gross alpha particle radiation
Molybdenum
Zinc
Selenium
Mercury
Lead
Chromium
Silver
Copper
Ammonium
Nitrate
Arsenic
3.2
Extent and Degree of Contamination
Monitoring at Facility E was performed at domestic wells, ground-water
monitoring wells, vadose zone lysimeters, and surface water locations. Well
locations are shown in Figure 3-1. These wells are screened in the unconfined
aquifer. Monitoring has been conducted since the summer of 1984. Four
3-
-------
OSWER Directive 9481.00-11
LEGEND
O Compliance Well
• Monitoring Well
® Vadoie Zone Neits
A Surface Water
Sample Location
800 1600
S
Scale, Feet
FIGURE 3-1. MONITORING AND COMPLIANCE WELL LOCATIONS
AT FACILITY E
3-2
-------
OSWER Directive 9481 00-11
contaminants have displayed concentrations or activities above background levels:
uranium, radium-226 and -228, molybdenum, and gross alpha radiation.
Samples have also been collected from private wells screened in deeper,
confined aquifers. These confined aquifers are separated from the unconfined
aquifer as discussed in Section 5.3. Samples from the confined aquifer show no
contamination over background levels; therefore, contamination appears to be
limited to the upper, unconfined aquifer.
Table 3-2 presents the most recent maximum observed concentrations of
uranium and molybdenum at different ground-water, surface water, and vadose
zone sampling points. Table 3-3 presents the most recent maximum observed
concentrations of other selected constituents and water quality parameters. All
monitoring results and a full description of the monitoring and analytical
procedures are presented in Appendix I of the DOE ground-water characterization
report for this facility.
Table 3-3 indicates that the background quality of the unconfined aquifer is
naturally brackish with TDS and sulfate in excess of the federal drinking water
standards of 500 mg/l and 250 mg/l, respectively. Deeper aquifers are less brackish.
The table also shows that there is some background level of radiation in the ground
water and, to a lesser extent, in the surface water. Most of the domestic wells
shown in the table have TDS and sulfate levels exceeding Federal standards. Some
also have detectable levels of contaminants, but these are below Federal drinking
water criteria (refer to Section 6 for a discussion of these criteria) and were not
associated with the plume emanating from the facility.
Contaminant plumes in the unconfined aquifer have been delineated on
isopleth maps for molybdenum (Figure 3-2) and uranium (Figure 3-3). The figures
indicate movement of the plume to the southeast and, in the case of uranium, that
the peak of the plume has passed the point of compliance (POC) and the facility
boundary. These measurements were made prior to closure of the waste pile, so
they indicate uranium source depletion rather than leachate reduction due to
facility closure measures. There is no evidence of molybdenum source depletion.
3-3
-------
OSWER Oirectiv« 9481.00-11
TABLE 3-2.
MAXIMUM OBSERVED CONCENTRATIONS OF ACL CONSTITUENTSa
Sample Type
Monitoring Wells
Compliance Wells
Well
MW-1
MW-2
MW-3
MW-4
MW-5
MW-6
MW-7
MW-8
MW-9
MW-10
MW-11
MW-1 2
MW-1 3
MW-1 4
MW-1 5
MW-1 6
MW-1 7
MW-1 8
MW-1 9
MW-20
MW-21
MW-22
MW-23
CW-1
CW-2
CW-3
Aquifer
Unitb
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
Uranium
(mg/L)
0.40
0.18
0.070
0.50
0.32
0.016
0.016
0.40
1.5
0.96
0.003
0.22
0.056
0.006
0.060
0.34
1.0
1.0
2.4
3.0
0.072
0.004
0.005
0.09
0.050
0.35
Molybdenum
(mg/L)
0.13
0.39
0.044
0.61
0.15
0.0036
0.001
0.37
0.46
0.026
0.012
- 0.24
0.031
0.016
0.060
0.13
0.22
0.022
0.038
0.028
0.029
0.012
0.013
0.006
0.03
0.14
3-4
-------
OSWER Directive 9481.00-11
, TABLE 3-2. (continued)
MAXIMUM OBSERVED CONCENTRATIONS OF ACL CONSTITUENTSa
Sample Type
Unsatu rated Zone
(Lysimeters)
Private Wei Is
Surf ace Water
Well
CW-4
CW-5
CW-6
CW-7
CW-8
CW-9
VN-1
VN-2
VN-3
W27
W28
W29
#24
#25
#26
Aquifer
Unitb
U
U
U
U
U
U
V
V
V
C
U
C
s
s
s
Uranium
(mg/l)
0.64
1.2
1.3
1.1
0.11
0.2
0.18
0.18
0.2
0.001
0.001
0.001
0.008
0.007
0.007
Molybdenum
(mg/l)
0.90
0.73
0.48
0.22
0.1
0.49
0.2
0.45
0.62
0.01
0.021
0.01
0.01
0.01
0.01
a Maximum analytical value for analyses performed since 1984
b U = Unconfined aquifer
C = Confined aquifer
V s Vadosezone
S a Surf ace water
3-5
-------
OSWER Directive 9481.00-11
TABLE 3-3.
MAXIMUM OBSERVED CONCENTRATIONS OF OTHER
CONSTITUENTS AND PARAMETERSa
Sample
Type
Background Wells
Compliance Wells
(downgradient)
Monitoring Wells
(downgradient)
Unsatu rated Zone
(Lysi meters)
Private Wei Is
(downgradient)
Surface Water
Well
MW-2
MW-3
W24
CW-3
CW-4
CW-7
CW-10
CW-12
MW-10
MW-12
MW-13
MW-15
MW-16
MW-19
MW-21
VN-1
VN-2
VN-3
W27
W28
W29
#24
#25
#26
Aquifer
Unitb
t
. -CJ
' U
c
U
U
U
U
U
U
U
U
U
U
U
U
V
V
V
c
U
c
s
s
s
Ra-226 and
Ra-228
(pCi/L)
0.1 ±.1
0.2 ±.2
0.5 ±0.3
0.3 ±.2
0.1 ±.1
~
2.0 ±.2
—
0.1 ±0.1
—
—
0.1 ±0.1
0.3 ±0.2
0.2 ±0.2
—
—
—
0±0.1
0±0.1
0.2 + 0.2
0.4 ±0.2
0.25 ±0.25
0.3 ±50.3
Gross Alpha
Particle
(pCi/L)
0.3 ±2.1
1.5±2.0
1.2 + 1.2
—
0.8 ±2.0
1.5 + 1.3
—
2.8±1.7
—
1.7+1.2
~
~
0.2 ±2.0
12.1
1.5±2.0
—
—
—
0.5 ±0.5
0±0.3
0.2 ±0.6
0.7±1.0
0.4+1.2
1.2 ±1.2
Sulfate
(mg/L)
625
225
212
—
2,210
2,420
--
2,210
1,590
2,200
1,440
643
2,280
3,770
1,290
40,000
70,400
5,152
261
570
230
410
390
380
TDS
(mg/L)
1,400
707
438
--
--
--
--
..
-
..
4,010
--
-
4,530
9,175
4,220
75,000
110,000
11,300
510
950
470
810
795
805
- Undetermined
3 Maximum analytical value for analyses performed since 1984.
b U = Unconfined aquifer V = Vadose zone C = Confined aquifer S = Surface water
3-6
-------
OSWER Directive 9481.00-11
Facility Boundary
0.0036 •
0.03 O
LEGEND
O Compliance W«ll
• Monitoring Wall
® Vados* Zone Nmti
A SurfacvWnar
Sampla Location
Not*: Conc%ntrrtiom in mo/L
800 1600
2=!!
Scalt, F«at
FIGURE 3-2. ISOPLETHS FOR MOLYBDENUM AT FACILITY E
3-7
-------
OSWER Directive 9481.00-1'
• u.io- ^,^-0.070/V.
_L2 p QjRwLJ -^V»
;;^^^ili;!ij;1i;;!;^*f%^ TV
flO.50 :::::::::::::.: 0.32 I X. ' X
LEGEND
O Complianca Wtll
• Monitoring Wttl
® VadoM Zont Nttti
Surface Water
Sampla Location
Not*: Connntration* in mo/L
FIGURE 3-3. ISOPLETHS FOR URANIUM AT FACILITY E
3-8
-------
OSWES Directive 9481 00-11
4.0 GENERAL INFORMATION
4.1 Land Use
The land uses in the vicinity of Facility E are shown in Figure 4-1. This figure
indicates that the facility is surrounded by a mixture of agricultural, residential,
industrial, and vacant lands. There are 22 residences within 1/2 mile of the waste
pile. The nearest reach of River 8 is 1,000 feet southeast of the facility boundary. A
private school is situated 1/2 mile southwest of the facility. City A, 2 miles north and
beyond the range of Figure 4-1, has 15,000 inhabitants.
Most of the land designated in Figure 4-1 as agricultural is vacant and is used
as rangeland. In the county in which Facility E is located, 80 percent of the land is
used as range, 10 percent as cropland, and 10 percent as residential, industrial, or
otherwise.
4.2 Water Use and Users
Ground water is the principal source of water for drinking, agricultural, and
industrial uses in the vicinity of Facility E. Figure 4-1 shows 17 private wells within
one mile of the waste pile. Table 4-1 lists the depth and use of each of these wells
and reveals that most wells are drilled into the confined aquifer systems. Only one
well is screened in the unconfined aquifer (well 28). This well, located 1/2 mile
south of the facility, is operated by a school for janitorial and groundskeeping
purposes. The school also operates a deeper well for drinking water. All water used
for industrial processes and human consumption is derived from deeper confined
ground water.
The uppermost aquifer is unconfined. The ground-water quality is poor, with
TDS commonly over 1,000 mg/l. The Federal and State drinking water standards
recommend 500 mg/l as a maximum amount of TDS. Ground-water allocation in
this State is governed under the doctrine of prior appropriation. Permits are
required from the state engineer for all ground-water withdrawals. Under this
authority, the State will not permit wells drawing from the unconfined aquifer for
4-1
-------
OSWER Directive 9481 00-11
1 Mile From
Waste Pile Boundary
. Vi Mile From
/^ Waste Pile Boundary
Housing Development
W5
© W4 °W2S""© VV26
LEGEND
Residential
Industrial
Agricultural:
Range &
Crop Land
Other
Well
Surface Water Sample
Location
FIGURE 4-1. LAND USES AND PRIVATE WELL LOCATIONS
4-2
-------
OSWER Directive 9481.00-11
TABLE 4-1.
INVENTORY OF WELLS WITHIN ONE MILE OF THE FACILITY
Well
W1
W3
W4
W5
W9
W10
W19
W20
W21
W22
W23
W24
W25
W26
W27 (Mission)
W28 (School)
W29 (School)
Well
Depth
(ft)
80
135
Not known
270
63
12a
35a
260
400
255
390
290
25a
360
310
30a
260
.Distance
from
Waste
Pile
(ft)
1,435
1,505
1,435
1,960
140
2,205
2,205
1,855
1,330
770
1,750
2,800
1,820
1,505
3,450
3,650
3,800
Direction
from
Waste
Pile
NW
NW
N
N
SW
SW
E
E
NE
NE
NE
NE
N
N
S
SW
SW
Use
Not in use
Domestic
Domestic
Domestic
Abandoned
Abandoned
Not in use
Domestic
Domestic
Domestic
Domestic
Domestic
Irrigation
Domestic
Domestic
Domestic
Domestic
Pump
Capacity
(gpm)
-
10
10
10"
•;-
-
-
20
10
10
10
20
50
10
30
10
20
a Unconfined, alluvial aquifer.
4-3
-------
OSWER Directive 9461 00-11
use as drinking water. (This policy is corroborated by documents provided in the
DOE reports.)
The unconfined aquifer is underlain by confined aquifers. The uppermost
confined aquifer lies at depths of roughly 30 to 60 feet; a deeper confined aquifer is
found at depths of roughly 80 to/130 feet; other deep aquifers lie below 160 feet.
These depths indicate that wells W1 and W3 (to the northwest) and W13 and W14
(to the southeast) draw water from the second confined unit. No active wells within
1/2 mile radius of the waste pile pump from the upper confined unit. The physical
characteristics of the confined aquifer systems are discussed in Section 5.
The well fields for City A's water supply system draw water from depths of 500
to 800 feet and are located nine miles north and northeast from Facility E.
Surface water uses are limited. The river water has a rather high TDS level.
Rivers A and B are used for occasional recreational fishing.
4.3 Precipitation
The climate for the region is semi-arid to arid as characterized by data from
the meteorological station in City A. The annual precipitation averages 8.8 inches
with roughly half falling during the months of April, May, and June. Table 4-2
presents the average monthly precipitation at the City A station. Detailed
meteorological data are provided in the DOE reports for Facility E.
4-4
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OSWER Directive 9481.00-1
TABLE 4-2.
MONTHLY PRECIPITATION*
Month
January
February
March
April
May
June
July
August
September
October
November
December
Year
Average Precipitation (inches)
0.21
0.25
0.52
1.32
1.81
1.26
0.67
0.44
0.76
0.82
0.53
0.20
8.79
Source: U.S. Department of Commerce, 1986.
*Based on 20 years of records.
4-5
-------
OSWER Directive 9481.00-11
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION
The geology and hydrology of this facility have been described in detail in the
DOE ground-water characterization report. This section summarizes the
information on regional and site geology and hydrology pertinent to this ACL
application.
5.1 Regional Geology
Facility E is located within the basin of River A, in the Middle Rocky Mountain
Physiographic Province some 50 miles east of the Continental Divide. The river basin
is bounded to the north, south, and west by Precambrian uplifts and to the east by
broad structural upfolds. Major topographical features are River A and River B (see
Figure 5-1) and nearby mountains rising to 13,000 feet.
The regional stratigraphy is dominated by interbedded sandstones, siltstones,
and shales with smaller amounts of bentonite, tuff, and limestone. These units
extend to a depth of nearly 2,000 feet and are Eocene in age. Surficial deposits in
this river basin are characterized by fluvial deposits, including terrace gravels and
recent river alluvium.
The region has a low seismic risk; no earthquakes greater than intensity level
VI have been recorded within 200 miles of the site, with records dating back to the
1890's.
5.2 Site Geology
The site is 2.5 miles upstream of the confluence of Rivers A and B, as shown in
Figure 5-1. Most surficial deposits on this valley floor are fluvial, and evidence of
River A and River B meandering is illustrated by this figure. The fluvial deposits
consist of sandy gravel that is imbricated and cross-bedded. Many of the meander
scars are filled with fine-grained sands. Beneath the site, alluvial materials vary in
thickness from 5 to 15 feet.
5-1
-------
Legend:
Elevation in Feet (MSL)
C.I.-50'
FIGURE 5-1. SITE LOCATION
0 1000 2000
ap—•
Scale. Feat
o
o
-------
OSWER Directive 9481 00-11
The lower strata have been characterized through a series of over 40 borings
performed at this site. The boring logs are presented and evaluated in Appendix B
of the DOE reports. Figure 5-2 identifies the boring locations used to prepare the
geologic cross sections shown in Figure 5-3 and 5-4. These profiles indicate that the
surficial sediments beneath the waste pile are underlain by discontinuous silty sands
(Oto 3 feet thick), cobbly alluvium (14 to 20 feet thick), the upper sandstone unit (0
to 17 feet thick), and shale (7 to 14 feet thick), followed by alternating layers or
stringers of sandstone and shale. As shown in Figures 5-3 and 5-4, the upper
sandstone unit pinches out in the central area of the site.
5.3 Ground-Water Hydrology
Ground water is present in unconfined and confined aquifer systems beneath
the facility (see Figure 5-4). The 20-foot layer of alluvial sand and gravel and
uppermost sandstone lying above the first confining shale layer constitutes the
unconfined aquifer system. The first confined system lies beneath the shale and
within the second sandstone unit. The lower confined aquifer systems are the
principal source of drinking water in the region and are at depths greater than 80
feet.
An extensive aquifer testing program was conducted at Facility E. The
unconfined aquifer, the first confined aquifer, and the next two deeper confining
layers were characterized using the monitoring wells at the site and some nearby
domestic wells. The extent and details of the program are discussed in the DOE
ground-water characterization report. Table 5-1 is a review of the aquifer
parameters interpreted from the aquifer pump tests and piezometer observations.
The water table in the uppermost (unconfined) aquifer is approximately 6 feet
beneath the natural ground surface and slopes to the southeast, toward River B
(Figure 5-5). Recharge to this aquifer is from precipitation and irrigation. Ground-
water elevations of the unconfined unit were monitored on a quarterly basis over
the past several years. The precise direction and gradient of the ground-water flow
varies seasonally. Recent water level measurements documented by the DOE have
5-3
-------
OSWER Directive 9481.00-11
LEGEND
Boring Location
FIGURE 5-2. LOCATION OF GEOLOGIC CROSS SECTIONS
5-4
-------
-4780
-4760
— 4740
4720
-4700
Unconfined
Aquifer
First Confined
er
Shato
-Second
•• Confined
Aquifer
Lower Confined Aquifers
0 100 200
Scale, Feet
O
LA
m
O
-1
it
*
vO
O
o
FIGURE 5-3. GEOLOGIC CROSS SECTION A-C
-------
cn
i
cn
-4860
Riwer B
•» . 'r
— Unconfined Aquifer
Sandsions
First Confined Aquifer
Sandstone
Second Confined Aquifer
Stul*
Lower Confined Aquifers
500
Scale. Feet
a
O
O
FIGURE 5-4. GEOLOGIC CROSS SECTION B-C
-------
OSWER Di recti ve 9481 00-11
TABLE 5-1.
AQUIFER PARAMETERS
Parameter
Value
Source
Area! dimensions
2600 ft x 1400 ft
Unconfined Aquifer*
Geologic material
Saturated thickness
Porosity
Hydraulic conductivity
Hydraulic gradient (horizontal)
silty sands, cobbly alluvium,
sandstone
14 to 40 ft
0.30 to 0.35
41.2 to 62.4 ft/day
(1.5x10-2 to 2.2x10-2 cm/sec)
.002 to .004
First Confining Layer**
Geologic material
Thickness
Porosity
Hydraulic conductivity
Hydraulic gradient (vertical)
shale
7 to 25 ft
0.05 to 0.10
8.03 x 10-5 to 2.74 x 10-4 ft/day
(2.8 x 10-8 to 9.7 x 10-8 cm/sec)
0.25
First Confined Aquifer
Geologic material
Thickness
Porosity
Hydraulic conductivity
Hydraulic gradient (horizontal)
sandstone
20 to 30 ft
0.30 to 0.35
16.3 to 43.3 ft/day
(5.8x10-3 to 1.5x10-2 cm/sec)
0.0024
,**
Second Confining Layer11
Geologic material
Thickness
Porosity
Hydraulic conductivity
Hydraulic gradient (vertical)
shale
20 to 70 ft
0.05 to 0.10
8.03 x 10-5 to 2.74 x 10-4 ft/day
(2.8 x 10-8 to 9.7 x 10-8 cm/sec)
0.28
The unconfined aquifer consists of terrace gravel deposits, river valley alluvium
and upper sandstone.
The confining layers consist of interbedded layers of siltstone and shale.
5-7
-------
OSWER Directive 9481.00-11
July, 1988
November, 1985
FIGURE 5-5. GENERALIZED FLOW DIRECTION WITHIN THE
UNCONFINED AQUIFER
5-8
-------
OSWER Directive 9481.00-11
indicated flow to the southeast in the summer and toward the south and southwest
in the late fall. Mean ground-water gradients in November 1985 and July 1986 were
0.0023 and 0.0036 ft/ft, respectively. Hydraulic gradients have been observed to
vary temporally between 0.002 and 0.004 ft/ft. The average linear velocity
calculated for ground-water flow within the unconfined aquifer is 0.43 feet per day.
Therefore, the travel time for water to travel from the waste pile to River B is
approximately 18 years.
The first confined unit is separated from the unconfined aquifer by the 12- to
24-foot upper sandstone and shale layers. Cores from these confining strata
revealed no evidence of fracturing. Piezometric head data presented in the DOE
reports indicate a maximum horizontal hydraulic gradient of 0.0024 ft/ft between
the waste pile and River B and a maximum vertical downward hydraulic gradient of
0.25 ft/ft across the first confining layer. Pump tests north and south of the site in
the upper confined aquifer show no interaction with the unconfined aquifer.
The second confined aquifer is separated from the uppermost confined
aquifer by a 25- to 45-foot-thick layer of shale (interrupted by occasional sandstone
stringers). Piezometric head data reveals a maximum vertical downward hydraulic
gradient of 0.28 ft/ft across the confining layer and a maximum horizontal gradient
of 0.0015 ft/ft toward River B within the second aquifer system. The second
confined system lies at a depth of 80 feet to 130 feet beneath the surface and is
used by several residents near the facility for domestic and agricultural purposes.
The deep aquifer is 500 to 800 feet below the surface and is pumped to supply
water to City A. This aquifer is separated from the upper aquifers by several thick
confining layers. The quality of water from the deep aquifer is good. The city well
fields are 9.0 miles north/northeast of the site. The potentiometric surface of the
lower confined aquifer is presented as Figure 5-6. Pumping over a period of 50
years has resulted in a 60 to 70 foot head drop in these wells. The resulting
hydraulic gradient, approximately 0.0035 ft/ft, induces flow of ground water
toward these wells.
5-9
-------
FIGURE 5-6. POTENTIOMETRIC SURFACE IN DEEP CONFINED AQUIFER
0 1000 2000
Scale. Feel
&
o
o
-------
OSWER Directive 9481.00-11
5.4 Surface Water Hydrology
The site is on a flat alluvial terrace roughly 2.5 miles upstream of the
confluence of Rivers A and B. These two rivers are the principal surface water
features in the area.
The River A basin is approximately 2,300 square miles in area, contributing a
mean flow of 13,300 cfs at a point upstream of the confluence with River B. The
mean flow in River B is 14,700 cfs. The minimum flow of record (monthly average
flows between 1950 and 1983) is 132 cfs for River A and 100 cfs for River B. These
flows were measured upstream of the confluence of the rivers, at the gauging
stations shown in Figure 5-1.
Both rivers have a history of channel migration. Paleo-channels from River A
are located near the site and meander scars from River B are within 500 feet (south)
of the site. These features are shown clearly in aerial photographs presented in the
DOE reports.
The 500-year floodplains for both rivers are shown in the DOE documents. The
500-year flood levels for River A are 4,940 to 4,944.5 feet above mean sea level
(MSL) in the vicinity of the site boundaries, but are not high enough to flow above
the road escarpment along the northern boundary nor enter from the southwest.
These levels would reach within 2,000 feet of the tailing pile and within 800 feet of
the northern boundary. The 500-year floodplain for River B has an elevation of
4,930 feet MSL in the vicinity of the site. At this elevation, floodwaters would rise to
a point approximately 500 feet from the site boundary.
Seasonal flow occurs in drainage ditches through the facility property and
adjacent to the waste pile (refer to Figure 5-2). The runoff control ditches
surrounding the waste pile direct storm water to the east and south.
5-11
-------
OSWER Directive 9481 00-11
6.0 EXPOSURE PATHWAYS
This section identifies the significant exposure pathways for humans or the
environment to the uranium and molybdenum leaching from the waste pile.
Section 3 presented evidence of plume migration from the waste pile toward River
B. This section demonstrates that human exposure may result from contamination
of wells in the unconfined aquifer or from contamination of River B. Environmental
exposure may occur in the River B ecosystem.
6.1 Potential Human Exposure
The possible paths of human exposure are oral exposure to the contaminated
ground water; oral exposure to contaminated surface water (following ground-
water discharge to that surface water); dermal exposure to contaminated ground
water or surface water; and exposure through the food chain via contaminated
terrestrial or aquatic organisms and agricultural products.
There appears to be limited current or potential likelihood for oral exposure to
contaminated ground water. Section 4 presented an inventory of all domestic,
agricultural, and industrial wells within a half mile of the waste pile, including all
wells between the waste pile and River B. This inventory identified only one active
well drawing from the unconfined aquifer. The well serves a school southwest of
the facility, providing water for janitorial andgroundskeeping purposes. The school
has informed Facility E (letter contained in DOE documents) that it plans to dose
this well and drill a new one in the lower confined aquifer in order to provide less
brackish water. Water quality analyses of wells in the unconfined aquifer (shown in
Table 3-3) reveal that the water is brackish, making it unpalatable and unsuitable
for drinking water according to the State drinking water standards. Oral exposure
is, therefore, possible but unlikely.
There are no wells downgradient of the waste pile that draw water from the
first confined aquifer. Furthermore, the plume from the waste pile is not expected
to leach into the second confined aquifer.
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OSWER Directive 9481.00-11
Future well construction in the unconfined and upper confined aquifers is
prohibited by the State under the authority of prior appropriation. A letter
provided in the DOE reports explains the commitment of the State engineer to deny
well construction permits in these two aquifer units within a one mile radius of the
waste pile on the basis of the brackish water quality and on the possible risk of
exposure to contaminants from Facility E. Enforcement and followup compliance
surveys are performed by the State to ensure that well drilling restrictions are being
followed.
Surface water contamination has not been observed along the reach of River B
where the plume discharges. Observed concentrations of both uranium and
molybdenum (see Table 3-2) are not elevated above background and are well below
State surface water quality standards. Prior to closure of the waste pile, several
drainage ditches on the facility property and downgradient of the facility showed
elevated levels of radioactivity. However, the waste pile closure was designed arid
constructed in accordance with EPA standards, and runoff from the waste pile cover
that discharges to the drainage ditches is free of contamination.
Dermal exposure may occur during swimming, bathing, or showering in
contaminated water. However, dermal contact to low levels of these contaminants
is a less significant exposure pathway than ingestion; consequently, ingestion, not
dermal exposure, is addressed in this application.
Food chain exposure may develop if terrestrial or aquatic ecosystems become
exposed to contaminated water. These exposure effects are addressed in the next
subsection.
6.2 Potential Environmental Exposure
Contaminated ground water discharging to River B may affect the aquatic
ecosystem; however, no ecosystem damage has been observed and no vulnerability
to low concentrations of radiation has been identified among the local aquatic
species (refer to study done by professional biologist in Appendix B of the DOE
report).
6-2
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OSWER Directive 9431 00-11
Upon leaving the vicinity of the waste pile, ground-water contaminants travel
within the unconfined aquifer until they discharge into River B. Although ground
water may rise to within 4 feet of the ground surface (in an area to the southwest of
the waste pile), no swamps or marshlands have been identified downgradient of
the site.
T
The vegetation in the path^of the plume is dominated by range grasses such as
wheat grass, sand dropseed, big sagebrush and rabbit brush. Animal life consists
mostly of reptiles, rodents, and fowl. Although burrowing animals may potentially
be affected by the contaminated ground water, no effects have been observed and
none of the local fauna are known to be vulnerable to low level radiation. The only
large mammals are mule deer and white tailed deer that inhabit an area near River
A. Most of the fowl are riparian.
In conclusion, environmental habitats in the area are not expected to become
exposed to high levels of the contaminants.
6.2.1 Endangered Species
Several threatened or endangered species have been observed in the vicinity
of City A and the surrounding areas. These include: bald eagle (Haliaectus
leucocophalus). peregrine falcon (Falco pereqrinus anatum). and black-footed
ferret (Mustela niqripes). Both the bald eagle and the peregrine falcon have been
known to nest in an area some 40 miles northwest of Facility E, but no nests have
been reported closer to the facility, and a reconnaissance of the facility did not
locate any nests. Furthermore, there is no documentation of either species being
sighted at or near the facility. The black-footed ferret is found only in or near
prairie dog towns. No prairie dog towns have been located in the area that overlies
the ground-water contamination. Furthermore, the human activity in this area
makes future habitation by the black- footed ferret unlikely in this area.
In conclusion, no endangered or threatened species are expected to be
exposed to the contaminant plume. The DOE reports provide documents from the
following sources to support this conclusion:
6-3
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OSWER Directive 9481.00-11
• Professional Biologist, employed by Facility E,
• U.S. Fish and Wildlife Service, and
• State Division of Wildlife Resources.
\
6.3 Maximum Allowable Exposure Concentrations
The critical exposure pathways identified above include human ingestion of
ground water and aquatic life exposure. Calculations of allowable exposure levels
for uranium and molybdenum for each of these pathways are shown below.
Uranium has been classified by the EPA as a Class A carcinogen, i.e., a known
human carcinogen. (Refer to Appendix B for a more detailed discussion of the
human health data for uranium.) A unit risk of 1.4 x 10-6/pCi/l has been estimated
for uranium. An allowable drinking water exposure concentration (C) for uranium
was calculated using the following ratio:
1.4x10-6 R 1.5pCi/l
(6-1)
where:
1 pCi/l C,pg/l 1 yg/l
R = Risk level, ranging from 10-4to 10-7; and
C = Exposure concentration, ug/l, conversion factor of 1 ug/l - 1 -5 pCi/l.
Based on the above ratio and ingestion of ground water, an allowable
concentration level for uranium at the 10-* risk level is 110 ug/l and at the 10-7 risk
level is 0.1 ug/l.
An acceptable daily intake (ADI) for oral exposure to molybdenum and
uranium (EPA, 1985) is 0.003 mg/kg/day (EPA, 1985) and 0.0017 mg/kg/day
(Appendix B), respectively. Assuming a daily intake of 2 I/day by a 70 kg adult, an
allowable drinking water concentration was calculated using the following
equation:
6-4
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OSWER Directive 9431 QO-I
/. ADI x 70 kg
C,mg/l - —— (6-2)
2 I/day
The allowable drinking water concentration for molybdenum was calculated as
0.1 mg/l. This assumes that 100 percent of the molybdenum dose is from drinking
water.
EPA has not established Federal surface water standards or criteria for the
contaminants. However, the State has set a water quality criterion for fish and
wildlife protection for uranium of 1.4 mg/l (this value is presented in Table 6-1). No
state standard or criterion is available for molybdenum.
The ground-water flow system at Facility E includes an unconfined aquifer and
a series of lower confined aquifers. Pumping at future wells screened in the
unconfined and uppermost confined units is not likely here because the State
manages a well permitting program that prohibits local domestic or agricultural
water supply well construction in these units. The potential contaminant receptors
(identified in Sections 6.1 and 6.2) include human and environmental receptors of
contamination reaching River B.
The exposure levels identified for both human health and the environment are
shown in Table 6-1. This application used the human health exposure
concentrations for uranium and molybdenum based on the ADIs as allowable
contaminant levels at the point of exposure. The ADI-based concentration level for
uranium was used instead of the 10-4 risk concentration level or the state water
quality criteria for fish and wildlife because it was lower and would therefore be
protective of all three exposure endpoints. A 10-4 risk level was chosen over other
risk levels because the likelihood of exposure to the contaminants is small due to
the brackishness of the ground water and the restrictions on well drilling in the
upper aquifers.
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OSWER Directive 9481.00-11
TABLE 6-1.
ALLOWABLE EXPOSURE LEVELS
Constituent
Uranium
Molybdenum
Drinking Water
•' Level
• (mg/l)
0,11 toO.OOOla
0.06b
0.1
State Fish
and Wildlife
Criterion
(mg/l)
1.4
NA
Site-Specific
Allowable
Concentration
(mg/l)
0.06
0.1
NA - Not Available
a - 10-* to 10-7 risk level
b • based on the ADI
6-6
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OS WE R Directive 9481 00-11
7.0
DEVELOPMENT OF ACLS
The ACLs proposed for Facility E are based on contamination in the unconfined
aquifer and potential contamination of River B that pose a potential threat to
human health and the environment. No contamination has been detected in the
upper confined aquifer, as would be expected because of its hydraulic isolation, and
the water from the unconfined aquifer is highly brackish withTDS values well above
Federal drinking water standards (refer to Section 3). The proposed alternate
concentration limits (ACLs) are calculated using the allowable concentrations shown
in Table 6-1. These ACLs are presented in Table 7-1.
TABLE 7-1.
PROPOSED ALTERNATE CONCENTRATION LIMITS
Constituent
Uranium
Molybdenum
Proposed ACL
(mg/l)
0.06
0.1
The proposed ACLs are based upon the following assumptions, data, and
procedures:
• Monitoring results indicate contaminant plumes flowing south-southeast
toward River B;
• The maximum allowable concentration for molybdenum is calculated
using the EPA recommended acceptable daily intake (ADI) of
0.003 mg/kg/day, assuming a daily intake of 2 L/day of drinking water for
a 70 kg adult; and
• The maximum allowable concentration for uranium is calculated using
the EPA recommended acceptable daily intake (ADI) of 0.0017
7-1
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OSWER Directive 9481.00-II
mg/kg/day. This assumed a daily intake of 2 L/day of drinking water for a
70 kg adult.
Since molybdenum and uranium concentrations have been detected above the
proposed ACLs, a corrective action program meeting the requirements of 40 CFR
192.33 and 40 CFR 264.100 must beput into action within 18 months.
7-2
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OSWER Di recti ve 9481.00-11
REFERENCES
EPA (U.S. Environmental Protection Agency), 1983. Standards for Management
of Uranium Byproduct Materials Pursuant to Section 84 of the Atomic Energy
Act of 1954, as Amended, Federal Register 48:45946. October 7
EPA (U.S. Environmental Protection Agency), 1985. National Primary Drinking
Water Regulations, Synthetic Organic Chemicals, Inorganic Chemicals and
Microorganisms; Proposed Rule. Federal Register 50:46976, November 13.
EPA (U.S. Environmental Protection Agency), 1987. Alternate Concentration Limit
Guidance. Part 1-Policy and Information Requirements, EPA/530-SW-87-017,
Washington, D.C., July.
Other Resource Documents
Freeze, R. A., and J. A. Cherry, Groundwater, Prentice-Hall, Inc., Englewood Cliffs,
New Jersey, 1979.
Kulthau, R. and G. Faust, RCRA Permit Writer's Guidance Manual -- Ground-Water
Protection. U.S. Environmental Protection Agency, Washington, D.C. 1983.
U.S. Environmental Protection Agency, Final Guidelines for Estimating Exposures,
Federal Register 51:34042-34054, September 24, 1986.
U.S. Environmental Protection Agency, Final Guidelines for the Health Risk
Assessment of Chemical Mixtures, Federal Register 51:34014-34025.
September 24,1986.
U.S. Environmental Protection Agency, Research and Development, Verified
Reference Doses (RfDs) of the U.S. EPA. ECAO-CIN-475, Environmental Criteria
and Assessment Office, Cincinnati, Ohio, January, 1986.
R-1
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OSWER Directive 9481.00-11
APPENDIX A
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
A-1
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OSWER Directive 9481.00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
Criteria for Assessing Potential Adverse Effects on Ar. r <-fll/jw
Ground-Water Quality: {Sinn £n y
§264.94(b)(1) Section No.
(i) The physical and chemical characteristics of the 3.1,3.2
waste in the regulated unit, including its
potential for migrations
(ii) The hydroqeological characteristics of the 5.1,5.2,5.3
facility and surrounding land;
(iii) The quantity of ground water and the direction 5.3
of ground-water flow;
(iv) The proximity and withdrawal rates of ground- 4.2
water users;
(v) The current and future uses of ground water in 4.1,4.2
the area;
(vi) The existing quality of ground water, including 3.2
other sources of contamination and their
cumulative impact on the ground-water
quality;
(vii) The potential for health risks caused by human 6.1,6.3-
exposure to waste constituents;
(viii) The potential damage to wildlife, crops, 6.2, 6.3
vegetation, and physical structures caused by
exposure to waste constituents;
(ix) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects;
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OSWER Di recti ve 9481 00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
(Continued)
Criteria for Assessing Potential Adverse Effects on ACL Case stucjv
Hydraulkally-Connected Surface-Water Quality: Section No.
(i) The volume and physical and chemical 3.1,3.2
characteristics of the Waste in the regulated
unit;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3,5.4
facility and surrounding land;
(iii) The quantity and quality of ground water, and 5.3,5.4
the direction of ground-water flow;
(iv) The patterns of rainfall in the region; 4.3
(v) The proximity of the regulated unit to surface 4.2
waters;
(vi) The current and future uses of surface waters in 4.1,4.2
the area and any water quality standards
established for those surface waters;
(vii) The existing quality of surface water, including 3.2
other sources of contamination and the
cumulative impact on surface water quality;
(viii) The potential for health risks caused by human 6.1, 6.3
exposure to waste constituents;
(ix) The potential damage to wildlife, crops, 6.2, 6.3
vegetation, and physical structures caused by
exposure to waste constituents; and
(x) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects.
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OSWER Directive 9481 00-11
APPENDIX B
GENERAL INFORMATION AND HAZARDOUS
CHARACTERISTICS OF MOLYBDENUM"!
AND IRIS (INTEGRATED RISK INFORMATION SYSTEM)
DATA BASE FOR URANIUM
'Adapted from: Dangerous Properties of Industrial Materials, Fifth Edition,
N.Irving Sax, 1979.
B-1
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OSWER Directive 9481.00-11
PHYSICAL, CHEMICAL AND BIOLOGICAL PROPERTIES OF
MOLYBDENUM
Summary
Molybdenum and Molybdenum compounds are somewhat toxic. Studies thus
far suggest precautions to be taken against the inhalation of considerable amounts
of Molybdenum compounds:
Properties and Health Effects
Cubic, silver-white metallic crystals or gray-black powder. Mo, atwt: 95.95, mp:
2622°,b: 5560°. d: 10.2, vap. press: 1 mm @ 3102°.
T
THR = See molybdenum compounds.
Radiation Hazard: For permissible levels, see Section 5, Table 5A.5.
Fire Hazard: Mod, in the form of dust, when exposed to heat or flame; violent
reactions with BrFa, CIF3, F2, PbO2 [19] See also powdered metals.
Explosion Hazard: Slight, in the form of dust, when exposed to flame. See also
powdered metals.
Acute toxdata: ipLDso (mouse) = 266mg/kg.[3]
THR a HIGH via intraperitoneal and subcutaneous routes. Molybdenum and
its compounds are said to be somewhat toxic, but in spite of their considerable use
in industry, industrial poisoning by molybdenum has yet to be reported. Some
studies have been made of its effects, and it is suggested that suitable precautions
should be taken against the inhalation of considerable amounts of the more soluble
molybdenum compounds. From animal experiments, it was found that no fatalities
occurred to those subject to molybdic oxide fumes for 25 1-hr exposures at an
average concentration of 1.5 mg/cu. ft of air, and only 1 fatality in 24 1-hr exposures
to molybdenite dust at an average concentration of 8.1 mg/cu. ft of air.
Molybdenum is not stored in the body to any extent because it is rapidly excreted.
8-2
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OSWER Directive 9481.00-11
Experiments with the sodium salts of hexavalent chromium, tungsten and
molybdenum have shown that sodium molybdate is the least toxic of the three, and
is less toxic following intraperitoneal injection than either sodium chromate
orsodium tungstate in equivalent concentrations. All molybdenum compounds can
be referred to molybdenum or to more toxic anions if present. Molybdenum has
caused anemia, poor growth rates, and diarrhea in cattle and sheep. Prolonged
exposure can lead to joint deformities and irritation of the mucus membranes
(Douil, etal, 1980). Recent studies have shown that molybdenum has importance as
a trace element in the normal growth and development of certain forms of plant
life. It is found also in animal tissue, although its precise function is unknown. It is a
common air contaminant.
REFERENCES FOR MOLYBDENUM
Doull, J., Klaasen, C, and Amdur, M., 1980. Casarettand Toxicology. MacMillan
Publishing Co., Inc., New York, N.Y.
3-3
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OSWER Directive 9481.00-! 1
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Uranium; CAS No. 7440-61-1 (Revised 09/30/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic toxicity data by work groups composed of U.S.
EPA scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in
particular risk management situations, but have not yet undergone comprehensive
U.S. EPA review. The risk management numbers (Section V) may not be based on
the most current risk assessment, or may be based on a current, but unreviewed,
risk assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4. j
STATUS OF DATA FOR Uranium
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: none
8. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Regulatory Actions: none
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Uranium
CAS No.: CAS No.: 7440-61-1
Information is not available at this time.
B-4
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OSWE* Directive 9481.00-11
B REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Uranium
CAS No.: CAS No.: 7440-61 -1
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Uranium (natural)
CAS No.: 7440-61-1 Preparation Date: 09/30/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification: A, human carcinogen, based on similarity to radium (as an alpha-
emitter), a known human carcinogen
1. HUMAN DATA
Sufficient. There is no direct information concerning the carcino- genicity of
ingested natural uranium; however, it is known to accumulate in bone and kidney.
Thus, dosimetric calculations based on the effect of ionizing radiation on organs can
be made based on experiences with exposures such as the atomic bomb survivors
and others. The weight of evidence classification is based on the data for alpha
radiation. Data on uranium miners is not pertinent as the species involved in
occupational exposure is inhaled radon. The radiotoxicity of uranium would be
expected to be similarto that of ingested radium, a known carcinogen and alpha
emitter which also accumulates in the bone.
2. ANIMAL DATA
Kidney tumors in rodents from ingestion of uranium have been reported
(Filippovaetal., 1978). Experimental data for mice and rats indicate that ingested
uranium leads primarily to kidney damage with a no-adverse-effect level of about 1
mg/kg/day.
3. SUPPORTING DATA
Natural uranium is 99.27% uranium-238, 0.7% uranium-235 and 0.006%
uranium-234 all of which are alpha emitters considered to cause cancer. The half-
lives of the three isotopes that comprise natural uranium and their relative
occurrence are different. At equilibrium, the activities (pCi/L) of uranium-234 and
uranium-238 are the same. However, uranium-235 is from a different natural
radioactive series. Thus if the isotopic mixture differs from that which occurs
naturally, the relative contributions to toxicity may be different.
B-5
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OSWER Directive 9481.00-11
Uranium accumulates in bone in a similar way to radium. Uranium emits alpha
and gamma radiation. Hence it is reasonable to believe that uranium will lead to
health effects in endosteal bone and red bone marrow in ways similar to the effect
caused by ingested radium.
The primary toxic effect of natural uranium in both humans and animals is on
the kidneys. Nephritis and changes in urine composition as a consequence of
uranium exposure indicate that both kidney structure and function are affected.
B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 5.6E-6/pCi/L
1. UNIT RISK SUMMARY TABLE
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/pCi/L)
70
pCi/L
7
pCi/L
0.7 1.4E-6 ICRP
pCi/L Linear
2. DOSE-RESPONSE DATA
The quantitative estimate was derived from the International Commission for
Radiological Protection (ICRP) dose-response model.
3. ADDITIONAL COMMENTS
The slope factor is the upper limit of the range in U.S. EPA (1986), 0.35 to 5.6E-
6 pCi/L. This was determined using the modified ICRP 30 dosimetric model, a linear
model that is used in ail radiation documents for standardization.
The Adjusted Acceptable Daily Intake (AADI) for uranium is 60 ug/L or 40pCi/L
based on a NOAEL (no-observed-adverse-effect level) of 1 mg/kg/day, a safety factor
of 100 since only animaJ data is used, and assuming an uptake of 1 % for animals and
5% for humans (U.S. EPA, 1986). It was assumed that an adult weighs 70 kg and
consumes 2 L of water/day.
At equilibrium 1.5 micrograms of natural uranium has activity of 1 picocurie.
This provides the conversion to obtain the water concentration from the ICRP 30
model.
This unit risk should not be used if the water concentration exceeds 7E + 3
pCi/L since above this concentration the slope factor may differ from that stated.
B-6
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05WER Directive 9481.00-11
4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE ESTIMATE
The largest contribution to the uncertainty in the risk estimates is due to that
involved in the pharmacokinetics, which could span a factor of 4.
C. INHALATION QUANTITATIVE ESTIMATE
Not available.
D. DOCUMENTATION AND REVIEW
1. REFERENCES
U.S. EPA. 1986. Water Pollution Control; National Primary Drinking Water
Regulations, Radionuclides. Federal Register. 51(189): 34836=34862.
U.S. EPA. 1985. Criteria Document for Uranium in Drinking Water. Draft.Office of
Drinking Water, Washington, DC. 20460. Available from NTIS.
Cothern, C.R., W.L. Lappenbusch and J.A. Cotruvo. 1983. Health effects guidance
for uranium drinking water. Health Physics. 44(1): 377-384.
2. REVIEW
These estimates and the criteria document have received extensive peer
review.
Agency Work Group Review: 12/17/86
Verification Date: 12/17/86
3. U.S. EPA CONTACTS
Primary: C.R. Cothern
Office of Drinking Water
Secondary: L.Anderson
Office of Drinking Water
202/382-7584 or FTS/382-2552
202/382-7587 or FTS/382-7587
B-7
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OSWER Directive 9481.00-11
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Uranium
CAS No.: 7440-61-1
Information is not available at this time.
IV. REGULATORY ACTIONS
Chemical: Uranium
CAS No.: 7440-61-1
Information is not available at this time.
V. SUPPLEMENTARY DATA
Chemical: Uranium
CAS No.: 7440-61-1
Information is not available at this time.
SYNONYMS: URANIUM; URANIUM (ACGIH); UN 2979 (DOT); URANIUM metal,
pyrophoric (DOT)
B-8
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OSWER Directive 9481.00-11
ACL
CASE STUDY 4
-------
OSWER Directive 9481 00-11
CONTENTS
SECTION PAGE
1.0 EXECUTIVE SUMMARY 1-1
2.0 INTRODUCTION . . 2-1
2.1 FACILITY DESCRIPTION 2-1
2.2 APPROACH TO ACL DETERMINATION 2-3
2.3 REPORT ORGANIZATION 2-4
3.0 IDENTIFICATION OF ACL CONSTITUENTS 3-1
3.1 HAZARDOUS CONSTITUENTS IN THE WASTE 3-1
3.2 EXTENT AND DEGREE OF CONTAMINATION 3-1
4.0 GENERAL INFORMATION 4-1
4.1 LAND USE 4-1
4.2 WATER USE AND USERS 4-1
4.3 PRECIPITATION 4-3
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION 5-1
5.1 REGIONAL GEOLOGY 5-1
5.2 SITE GEOLOGY 5-2
5.3 GROUND-WATER HYDROLOGY 5-5
5.4 SURFACE WATER HYDROLOGY 5-9
6.0 EXPOSURE PATHWAYS 6-1
6.1 POTENTIAL HUMAN EXPOSURE 6-1
6.2 POTENTIAL ENVIRONMENTAL EXPOSURE 6-4
6.3 MAXIMUM ALLOWABLE EXPOSURE CONCENTRATIONS 6-4
7.0 DEVELOPMENT OF ACLs 7-1
7.1 STATISTICAL ANALYSIS OF SURFACE WATER
CONCENTRATIONS 7-1
7.2 PROPOSED ACLS 7-7
8.0 MONITORING PROGRAM 8-1
8.1 GROUND-WATER MONITORING 8-1
8.2 SURFACE WATER MONITORING 8-1
in
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OSWER Directi ve 9481.00-1
CONTENTS (continued)
REFERENCES R-1
APPENDICES
A LOCATION OF INFORMATION IN THE CASE STUDY A-1
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1 id §264.94(b)(2)
B CHEMICAL AND PHYSICAL PROPERTIES OF B-1
CHLOROBENZENE, DICHLOROBENZENES,
ETHYLBENZENE, AND TOLUENE; AND IRIS
(INTEGRATED RISK INFORMATION SYSTEM)
DATA BASE FOR ETHYLBENZENE AND TOLUENE
C RESULTS OF STATISTICAL TESTS C-1
IV
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OSWER Directive 9481 00-11
TABLES
NUMBER PAGE
3-1 Maximum Concentratiens in Ground Water for ACL 3-4
Constituents /
3-2 Maximum Concentrations in Surface Water and Sediments for 3-10
ACL Constituents
4-1 Inventory of Wells Within 1000 Feet of the Facility 4-3
4-2 Monthly Precipitation 4-4
5-1 Aquifer Characteristics 5-7
6-1 Allowable Surface Water Exposure Levels 6-2
6-2 Bioconcentration Factors (BCF) for Fish 6-4
7-1 Summary Statistics for Water Samples 7-3
7-2 Summary Statistics for Sediment Samples-Chlorobenzene 7-4
7-3 Parameters and Results for Test of Proportions for Water 7-5
Samples
7-4 Proposed Alternate Concentration Limits 7-8
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OSWER Directive 9481.00-11
FIGURES
NUMBER PAGE
2-1 Site Layout , 2-2
3-1 Monitoring Well Locations 3-2
3-2 Isopleths for Total Maximum Concentrations of 3-5
Chlorobenzenes (pg/l)
3-3 Isopleths for Maximum Concentrations of Ethylbenzene (ug/l) 3-6
3-4 Isopleths for Maximum Concentrations of Toluene (ug/l) 3-7
3-5 Surface Water and Sediment Sampling Station Locations 3-9
4-1 Land Uses and Offsite Well Locations 4-2
S-1 Plan View of Area in Fence Diagram 5-3
5-2 Fence Diagram Representing Geology of Facility B 5-4
5-3 Water Table Contours 5-8
8-1 Compliance Well Locations 8-2
VI
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OSWER Directive 9*81.00-11
1.0 EXECUTIVE SUMMARY
Case Study 4 is a hypothetical example of an application by Facility B for
alternate concentration limits (ACLs) under 40 CFR 264.94(b) for hazardous
constituents detected in the ground water at the facility. This case study illustrates
the approach outlined in Case 4-of Part I of the ACL Guidance Document (EPA,
1987). Part I states that ACLs may be based on contaminant discharge into a surface
water body if a facility owns the property up to the surface water body. This should
only be allowed if: (1) the contaminant plume has already reached the surface
water body, (2) the contaminants do not cause a statistically significant increase
over background in the surface water concentrations of those contaminants, and (3)
the contaminants will not reach a receptor at an unsafe level before they reach the
surface water body. Although it may be acceptable to allow some contaminants in
the ground water to discharge into a nearby surface water body, in no case may the
ACL be derived so as to allow releases into that surface water body that result in a
statistically significant increase in the concentration of the contaminants in the
surface water body.
Facility B is located in a river basin at the junction of a river and a creek in the
southeastern United States. The surrounding area consists of marshland, forest, and
a few scattered homes. Three miles away is a small city containing some 10,000
inhabitants. Ground water is a source of drinking water for some of the local
residences, but there are np wells within 500 feet of the facility boundary. The
principal source of water for the city is the river adjacent to the facility. The intake
is several miles upstream of the facility.
Five hazardous constituents are present in ground water at the site:
chlorobenzene, o-dichlorobenzene, p-dichlorobenzene, ethylbenzene, and toluene.
All contamination is discharging to surface water via the ground-water flow. Some
contaminants of concern have been detected in the adjacent surface waters;
however, none have been found at levels statistically greater than the background
levels of those contaminants in the surface water bodies.
Potential exposure pathways for humans and ecosystems are discussed in this
application. The principal route of contaminant migration is through ground water
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OSWER Directive 9481.00-11
into surface water. Allowable exposure levels for (1) human drinking, (2) human
drinking and fish ingestion, and (3) acute and chronic ecosystem exposures are
developed, compared, and evaluated for each of the five contaminants.
Concentrations of the ground-water contaminants have been declining since
1985 and none of the contaminates exceed their allowable surface water exposure
levels in the surface water bodiei The ACLs proposed for ethylbenzene and toluene
are based on the allowable surface water exposure levels. The ACLs proposed for
chlorobenzene, o-dichlorobenzene, and p-dichlorobenzene are based on the
current levels in the ground water and a showing of no statistically significant
increases in the surface water bodies.
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OSWER Directive 9481 00-11
2.0 INTRODUCTION
Part I of the ACL Guidance Document (EPA, 1987) describes five cases that
show how the ACL guidance and policy should be applied to ACL demonstrations.
The demonstration presented in tlfis case study meets the conditions of Case 4. In
Case 4, ACLs may be based on contaminant discharge into a surface water body if a
facility owns the property up to the surface water body. The permitting authority
should allow this only if: (1) the contaminant plume has already reached the
surface water body, (2) the contaminants do not cause a statistically significant
increase over surface water background concentrations of those contaminants, and
(3) the contaminants will not reach a receptor at an unsafe level before they reach
the surface water body.
This demonstration is part of the facility's Part B permit application for
operating hazardous wastewater treatment surface impoundments (lagoons) until
September 1988 and then closing them in accordance with the agreement between
the facility and the U.S. EPA (see Appendix 1 of the Part B permit application).
The point of compliance (POC) is the location on the downgradient side of the
regulated units where the ground-water protection standard must be met. The ACL
for each hazardous constituent of concern is set here. As discussed in Section 8 of
this application, the POC is adjacent to the wastewater treatment surface
impoundments. Because the distance between the POC and the adjacent river is so
small, no attenuation of the plume in the ground water will be assumed in
determining the ACLs proposed in this demonstration.
2.1 Facility Description
Facility B is a chemical plant specializing in the manufacture of sulfur dyes,
disperse dyes, and miscellaneous organic chemicals, including benzene compounds
and other solvents. The facility includes a wastewater treatment area (Figure 2-1),
with 11 unlined treatment surface impoundments permitted under the National
Pollutant Elimination Discharge System (NPDES). Because these surface
impoundments receive hazardous wastes, they are also subject to the Resource
Conservation and Recovery Act(RCRA). Detailed drawings of each regulated unit
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OSWER Directive 9481.00-11
Residential
and
Commercial
Final
Aeration "*• J Primary
Settling
>v /To Community B
FIGURE 2-1. SITE LAYOUT
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OSWER Directive 9481 00-11
are provided in Sections A and B and Plates 1 through 5 of the Part 8 permit
application. Because contamination (consisting of chlorobenzene, o- and p-
dichlorobenzene, ethylbenzene, and toluene) has been detected in the ground
water, process changes were introduced in early 1985 to reduce the concentration
of these constituents discharged to the wastewater treatment surface
impoundments. Past and current operational practices at Facility B are discussed in
Section B of the Part B permit application.
In recognition of the November 1988 deadline for regulated surface
impoundments to meet minimum technology requirements, Facility B has elected to
close its wastewater treatment surface impoundment facility prior to the deadline
and replace it with a new, totally enclosed wastewater treatment plant. Thus,
retrofitting of the large surface impoundment complex will not be required. The
surface impoundments will be "clean closed," thereby removing the source of
contamination and preventing any further releases into the ground water.
2.2 Approach to ACL Determination
Facility B, as described in Section 4.1, is located at the junction of a river and a
creek in the Piedmont area of the southeastern United States. The facility property
extends to .both of these water bodies. The surficial aquifer beneath the facility has
been contaminated. Ground-water contamination extends to the surface water
bodies. Data indicate that all the ground water discharges to these surface waters.
Consequently, this ACL demonstration is representative of Case 4 described in the
ACL Guidance Document.
This ACL application is based on the evaluation of human health and
environmental protection criteria in the surface water bodies (Stream B and River
A), including human ingestion of fish, human ingestion of fish and drinking water,
and water quality criteria for aquatic life. Ground-water pathways are not
evaluated because all ground-water contamination is known to discharge to the
river and because Facility B will prevent the use of ground water on its property for
industrial or domestic purposes. Because the distance between the POC and the
adjacent river is small, no attenuation of the constituents in the ground water is
assumed in determining the ACLs proposed herein.
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OS WE R Directive 9481.00-11
2.3 Report Organization
This application is presented in eight sections: executive summary,
introduction, identification of ACL constituents, general information, geologic and
hydrologic information, exposure pathways, development of alternate
concentration limits, and the monitoring program. The ACL criteria listed in 40 CFR
264.94(b) are discussed within these eight sections. Appendix A contains a cross-
reference of the 19 ACL criteria to the applicable section in this application.
Appendix B provides chemical, physical and biological properties of the five
constituents and data from the integrated risk information system (IRIS) for
ethylbenzene and toluene. Appendix C provides results of the Student's t-test
statistical analysis.
The discussion in these sections presumes a familiarity with information given
in the RCRA Part B permit application for this facility. This ACL application presents
the arguments for the ACL demonstration for this facility. Data that appear in the
Part B permit application are not reproduced in this document unless deemed
necessary for clarity and continuity.
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OSWER Directive 9431 00-11
3.0 IDENTIFICATION OF ACL CONSTITUENTS
3.1 Hazardous Constituents in the Waste
Hazardous wastes treated at this site consist of the following:
• D002 - Acidic Wastewater: The acid sewer collects acidic wastewaters
classified as corrosive with a normal pH of 1 to 2. On the average, 1.1
million gallons of acidic waste are generated daily, primarily from
disperse dye manufacturing and from nitration/sulfonation filtrates.
• D003 • Alkaline Wastewater with Traces of Sulfides: The alkaline sewer
collects alkaline wastewater from sulfur dye production operations such
as de minimus process losses, equipment cleaning and operating, and
occasional off-specification material disposal. On the average,
approximately 1.75 million gallons of alkaline wastewater are generated
daily.
• FQ02. FQ03: Both the acid and alkaline waste streams can contain small
quantities of these solvents from production losses and from two
manufacturing filtrates. F002 wastes include chlorobenzene, o-
dichlorobenzene, and p-dichlorobenzene. F003 wastes include
ethylbenzene and toluene.
3.2 Extent and Degree of Contamination
3.2.1 Ground-Water Contamination
The hazardous constituents for which ACLs are requested include
chlorobenzene, o-dichlorobenzene, p-dichlorobenzene, ethylbenzene and toluene.
All five constituents have been detected in the ground water beneath the site.
Monitoring wells have been installed at the locations shown in Figure 3-1.
Onsite nested wells are designated NW-1 through NW-7. Off-site nested wells are
designated NW-8 through NW-12. There are 23 additional wells onsite variously
designated as SP, LF, and WQ series wells.
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OSWER Directive 9481.00-11
LEGEND
O SP Series Well
• LF Series Well
WQ Series Well
Q NW Nested Well
FIGURE 3-1. MONITORING WELL LOCATIONS
-H-
500 1000
iZ
Scale, Feet
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OSWER Directive 9481 00-11
Sampling and analysis programs have been conducted since 1982. All
monitoring results and monitoring and sampling protocols are described in Section I
of the Part B permit application. Samples collected prior to 1987 were analyzed for
Appendix VIII constituents; samples collected during 1987 were analyzed for
Appendix IX constituents. The results indicate elevated levels of the chlorobenzenes
(o-dichlorobenzene, p-dichlorobenzene, and chlorobenzene), ethylbenzene, and
toluene. The maximum concentrations observed prior to and during 1987 for these
five constituents are presented in Table 3-1. Wells for which no constituents were
detected are not shown.
As can be seen from Table 3-1, the concentrations of the five constituents have
declined in all monitoring wells. The monitoring data provided in Section I of the
Part B permit application thoroughly documents this decline. For example, the data
for chlorobenzene for one representative well, Well WQ-3, located in the center of
the contamination, show a maximum concentration in 1985, of 500 ug/l. The
concentration has declined steadily since. As of early 1987, the chlorobenzene
concentration was 440 ug/l. The most recent sampling (reported to the U.S. EPA in
January, 1988) showed a concentration of chlorobenzene in the well of 400 ug/l. A
similar trend is shown for the five constituents in all wells. The decline is attributed
to the manufacturing process change that lowered concentrations of constituents in
the wastewater discharged to the surface impoundments.
The horizontal extent of the maximum concentration plumes are shown for
total chlorobenzenes (Figure 3-2), ethylbenzene (Figure 3-3), and toluene (Figure 3-
4). The total chlorobenzenes plume shows the combined maximum concentrations
of chlorobenzene, p-dichlorobenzene and o-dichlorobenzene. The plumes indicate
that the contaminants are moving toward the river and the creek.
The vertical distribution of the plumes has not been mapped. However, the
five constituents have not been detected in the ground-water samples collected
from the competent bedrock. Nor have constituents been detected in wells NW-8
through NW-12 west of the river or wells NW-3 through NW-6 east of the creek.
These data indicate that all contamination is discharging into the surface water
bodies rather than flowing beneath.
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TABLE 3-1.
MAXIMUM CONCENTRATIONS IN GROUND WATER FOR ACL CONSTITUENTS
(ppb. iig/l)
Well
WQ 3
WQ-8
WQ-9
WQ-10
WQ-15
SP-1A
SP-1B
SP-1C*
SP-2
SP-3
SP-4A
SP-4B
SP-5
SP6
SP-7
SP-8A
SP-8B
LF-6
NW-1A
NW-1B
NW-2A
Chlorobenzene
1982-1986
500
2
<5**
25
<5
230
100
<5
4
300
50
200
<5
<5
<5
500
330
<5
<5
<5
<5
1987
440
<5
<5
22
<5
205
89
<5
2
260
40
180
<5
<5
<5
435
290
<5
<5
<5
<5
o-Dichlorobenzene
1982-1986
1,500
6
30
320
<10
450
1,240
<10
35
1000
750
1000
35
30
25
2000
2000
20
<10
<10
<10
1987
1,260
2
26
290
<10
390
1,040
<10
28
850
640
890
25
24
20
1,650
1,590
18
<10
<10
<10
p-Dichlorobenzene
1982-1986
1,000
2
<10
80
<10
85
220
<10
6
420
300
400
<10
<10
<10
710
70
<10
<10
<10
<10
1987
835
<10
<10
65
<10
73
185
<10
3
350
270
335
<10
<10
<10
605
62
<10
<10
<10
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OSWER Directive 9481.00-11
LEGEND
O SP Series Well 9 WQSer.es Well
• LF Scries Well D NW Nested Wall
0 500 1000
Scale, Feet
FIGURE 3-2. ISOPLETHS FOR TOTAL MAXIMUM CONCENTRATIONS
OF CHLOROBENZENES (ug/1)
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OSWER Directive 9431.00-11
LEGEND
O SP Series Well $ WQ Series Well
• LF Series Well O NW Nested Well
-N-
0 - 500 1000
3SSSS
Scale, Feet
FIGURE 3-3. ISOPLETHS FOR MAXIMUM CONCENTRATIONS
OF ETHYLBENZENE (ug/Jt)
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OSWER Directive 9481.00-11
LEGEND
O SP Series Well 9 WQ Scries W«ll
• LF Series Well Q NW Nested Well
0 500 1000
Scale, Feet
FIGURE 3-4. ISOPLETHS FOR MAXIMUM CONCENTRATIONS
OF TOLUENE (ug/X )
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OSWER Directive 9481.00-11
3.2.2 Surface Water Contamination
*
As indicated in the ACL Guidance Document, ACLs may be established based
on contaminant discharge into a surface water body. This is allowable only where
the contaminant plume has already reached the surface water body and the
constituents do not cause statistically significant increases in contaminant levels
over background in the surface water.
To evaluate the potential for statistical differences between upstream and
downstream concentrations of the five hazardous constituents of concern, surface
water samples were collected from both River A and Creek B. Samples were
collected during flow representative of the seasonal mean values. Sediment
samples were collected at the same time and locations. The locations of the water
and sediment sampling stations are shown in Figure 3-5. The maximum values for
the five hazardous constituents of interest are summarized in Table 3-2. !
Chlorobenzene has been detected at all stations in River A at some time during
sampling. Only at two stations, SW-2 and SW-5, on River A, have o-dichlorobenzene
and p-dichlorobenzene been detected. None of the other constituents has been
detected in River A and no constituents have been detected in Creek B. The
concentrations detected were analyzed for statistical significance, as discussed in
Section 7 of this ACL application.
None of the five constituents have been detected in annual analyses of the
wastewater treatment system effluent. Under the requirements of the NPDES
permit, indicator parameters in the effluent stream are monitored weekly.
Although the five constituents are not among the parameters specified on the
NPDES permit, the monitoring requirements serve to ensure proper operation of
the wastewater treatment system.
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OSWER Directive 9481.00-11
LEGEND
0 SW Surface Water Sampling Station
Sediment Sampling Station
FIGURE 3-5. SURFACE WATER AND SEDIMENT SAMPLING
STATION LOCATIONS
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OSWER Directive 9481.00-n
TABLE 3-2.
MAXIMUM CONCENTRATIONS IN SURFACE WATER
AND SEDIMENTS FOR ACL CONSTITUENTS
A. SURFACE WATEfcANALYTICAL RESULTS (ug/l; ppb)
Surface Water
Sampling
Station
SW-1
SW-2
SW-3
SW-4
SW-5
SW-6
SW-7
SW-8
Chlorobenzene
31
44
49
31
41
<5*
<5
<5
o-Oichlorobenzene
<10
12
<10
<10
18
<10
<10
<10
p-Dichlorobenzene
<10
<10
<10
<10
<10
<10
<10
<10
Ethylbenzene
<5
20
<5
<5
8
<5
<5
<5
Toluene
<5
<5
<5
-<5
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OSWER Directive 9481.00-11
4.0 GENERAL INFORMATION
4.1 Land Use
Facility B is located at the junction of River A and Creek B in the Piedmont area
of the southeastern United States. The waste management portion of the facility is
bounded on the south, east and west by these waters as depicted in Figure 4-1.
Most of the surrounding area consists of forest and marsh with some scattered
residences. A small city of approximately 10,000 inhabitants (City A) is located 3
miles northwest of the facility. Northeast of the facility is a residential and
commercial development with approximately 250 inhabitants. There is also a small
residential development approximately 1/2 mile east of the facility with
approximately 130 inhabitants. These land uses are depicted on Figure 4-1. More
detailed land use maps are presented in Section B of the Part B permit application.
4.2 Water Use and Users
River A is the principal source of water for City A. The water intake for City A is
several miles upstream of the facility. The small suburban area east of the facility is
served by a different municipal water supply system that also draws water from
River A several miles upstream of the facility. The nearest downstream intake is 10
miles from the facility and serves some 5,000 people who live in Community B.
Community B water is pumped at a current rate of 3 mgd, though the water
treatment facility has a capacity to handle 7.5 mgd. The water treatment process is
not designed to remove volatile or base/neutral organic compounds. However,
water pumped from the river has been routinely tested since 1982 for priority
pollutants. No priority pollutants have been detected in the influent water to the
treatment plant (Community B Engineer's Office, 1987).
Ground water is the source of drinking water for some of the rural residences
beyond the facility boundary. No wells east of the river and within three miles of
the facility serve more than a single residence, and there are no wells within 500
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OSWER Directive 9481.00-11
Fors«
and
Mann
Residential
and
Commercial
OW-1
OW-2
Foreit
-N-
To Community 8
0 500 1000
Scale, Feet
LEGEND
« Off-Sitt Well
FIGURE 4-1. LAND USES AND OFF-SITE WELL LOCATIONS
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OSWER Directive 9481.00-11
feet of the facility boundary. The five wells within 1000 feet of the facility are
shown in Figure 4-2 and described in Table 4-1. The one commercial well (OW-2)
serves a small gasoline station. These five wells have been tested periodically since
1984 for priority pollutants. No organic pollutants have been found above
detection limits («^1 ug/l; see Part B permit application, Section E).
/ TABLE 4-1.
INVENTORY OF WELLS WITHIN 1000 FEET OF THE FACILITY
Offsite
Well
OW-1
OW-2
OW-3
OW-4
OW-5
Aquifer
Unconfined
Unconfined
Unconfined
Unconfined
Unconfined
Water Level
Ground
Elevation
(ft)
600
685
635
630
675
Well
Depth
(ft)
45
50
35
35
40
Depth
to Water
(ft)
24
28
16
14
20
Pump
Capacity
(gpm)
10
20
10
10
10
Use
Domestic
Commercial
Domestic
Domestic
Domestic
4.3
Precipitation
The mean annual precipitation for the site is 48 inches. Table 4-2 lists mean
monthly precipitation based on data collected between 1973 and 1986 at the
facility.
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OSWER Di recti ve 9481.00-11
TABLE 4-2.
MONTHLY PRECIPITATION'
Month
January
February
March
April
May
June
July
August
September
October
November
December
Total
Mean Monthly Precipitation
(inches)
3
2
6
7
6
5
-
4
2
2
2
4.
48
* Based on data collected onsite between 1973
and 1986.
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OSWER Directive 9481.00-11
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION
The geology and hydrology of the facility are described in detail in Sections D,
E, and F of the Part B permit application. This section summarizes the regional and
•?
site geology and hydrology pertinent to this ACL demonstration.
5.1 Regional Geology
The facility is in the Piedmont Physiographic Province, an area that extends
from Alabama to New York and varies from 10 to 125 miles in width. The Piedmont
province has broadly rolling topography, with local ridges and valleys that show
relief of 50 to 300 feet. Regional topographic slopes are approximately 20 feet per
mile to the east. Elevations range from less than 100 feet mean sea level (MSL) at
the western margin of the coastal plain to 1500 feet MSL at the foot of the Blue
Ridge escarpment.
The bedrock of the Piedmont province consists primarily of metasedimentary
and metaigneous rocks (schists, gneisses, quartzites, and slates) of Precambrian and
Paleozoic age and igneous rocks of Paleozoic age. The Piedmont region also
contains areas of Triassic sedimentary rocks and a zone of slates, graywackes,
pyroclastics, and lavas that have been only moderately metamorphosed. This zone
is believed to be of Paleozoic age.
Igneous intrusions and episodes of repeated stress are reflected by the folds,
faults, and fractures present in the rocks throughout the area. The Triassic rocks
reveal little folding or metamorphism, but they have been tilted and broken by
normal faulting. Triassic dikes are common in the metamorphic rock belt of the
Piedmont. In some places, igneous activity accompanied Triassic sedimentation,
resulting in sedimentary rocks interbedded with basaltic flows or intruded by
diabase dikes and sills. The Piedmont has been differentially uplifted since the
Triassic, but no significant tectonic deformation has taken place since that time.
The facility is not in a seismically active area as defined in RCRA regulations (40 CFR
264.18a).
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OSWER Directive 9481.00-11
Surficial deposits of the Piedmont province consist of residual soils formed
from m situ weathering of the underlying bedrock and moderately well-sorted
alluvium deposited by the streams and rivers in the region. Jointing and fracturing
in the bedrock of this region is primarily oriented northeast-southwest with some
oriented northwest-southeast.
5.2 Site Geology
Geology of the site area has been characterized by field investigations that
have included soil borings and the installation of monitoring wells. Figure 5-1
shows the area depicted by a fence diagram. Figure 5-2 is a fence diagram,
prepared from the available well logs, depicting surficial and subsurface geology
at the facility.
In the facility area, surficial materials consist primarily of fill, alluvium, and
residuum (saprolite). The fill occurs mostly in the area of the impoundments on the
southwestern side of the site. The alluvium primarily occurs adjacent to River A,
west of the site, and Creek B, east of the site. The alluvium consists of loose to firm
silty sands and sandy silts with some gravel, clay, and organic materials. The
residuum at the facility usually occurs below the alluvium and above the weathered
rock and typically consists of silty fine sands and fine sandy silts derived from in-
place weathering of the parent bedrock. The residuum encountered during drilling
at the site was thickest in the east and northeast areas of the facility. At the base of
the residuum, near the center of the facility, sand- and gravel-size particles were
encountered. Elsewhere, where the sand- and gravel-size particles are absent, silt
and sand and partially weathered rock directly overlie the bedrock.
Bedrock, encountered during drilling at the site, is a slightly weathered, grey
diorite that occurs at a depth of about 28 to 30 feet. The typical weathered-rock
hydraulic conductivity values are 10-5 to 10-4 cm/sec in the site area. The joints and
fractures in the bedrock follow regional patterns. The bedrock fractures tend to
become much tighter below 540 feet in elevation (MSL) and the competent bedrock
conductivity values range from 10-7 to 10-6 cm/sec.
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OSWER Directive 9481.00-11
FACILITY B
L'"' LEGEND
0 500 1000
Scale, Feet
O SPS«rieiW«ll WQS«ri«Well
LF S«riej Well D NW Netted Well
FIGURE 5-1. PLAN VIEW OF AREA IN FENGS DIAGRAM
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LEGEND
OSWER Directive 9431.00-11
Fill
Alluvium
SP1
SP8
SP6 Elevation
596.8
f— 590
j Residuum
[•.-• •.: :\ Residual Sand and Gravel-Size
'"•"'" ' Fragments
|^ Partially Weathered Rock
;'£&? Bedrock S/M
1 SP2
? Inferred
WQ9
LP6
Previous Boring
ByOtnm
NW4
WQ8
I
-N-
Horizontal Scale: V-250'
Elevations in Feet (MSL)
FIGURE 5-2. FENCE DIAGRAM REPRESENTING GEOLOGY OF
FACILITY B
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OSWER Directive 9481 00-11
5.3 Ground-Water Hydrology
5.3.1 Regional Hydrology
The source of ground-water recharge in the Piedmont province is largely from
precipitation. In the residuum (weathered rock), ground water is usually stored in
the pore spaces. In the unweatfiered rock, it occurs in joints and fractures. The
depth to the water table in the Piedmont depends on the degree of weathering of
the rock and the topography; ground water may be obtained from shallow wells
constructed in the weathered material.
The Piedmont province is a region of generally low well yields, supplying
ground water for light industry, domestic supply, and small municipalities. In areas
underlain by crystalline rock, moderate yields may be obtained by wells drilled into
the lower part of the weathered zone and the upper part of the fractured rock.
Although some wells may yield up to 400 gpm, typical yields are 10 to 15gpm. The
background quality of ground water in this region meets all federal and state
drinking water criteria.
Regional ground-water maps and USGS publications indicate that ground-
water flow directions are normally consistent with surface water drainage basin
flow; that is, the ground-water table usually reflects the natural topography .and
surface water courses generally serve as ground-water discharge areas. The
drainage pattern and surface topography of the Piedmont reflects the major joint
system.
5.3.2 Site Hydrology
Ground water at the site area occurs in the soil and underlying rock units as a
single unconfined aquifer. In the weathered bedrock, ground water occurs in
fractures and joints.
Water table elevations at the site range from approximately 563 feet MSL near
the river, to 612 feet MSL in the northeastern corner of the facility. Section D of the
Part B permit application provides more detailed information collected from
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OSWER Directive 9481 00-11
monitoring wells at the site, including elevation of well head, depth of well,
elevation of screen interval, and water table elevations.
There is a localized ground-water divide east of the surface impoundments.
East of this divide, ground water flows toward the creek, where it discharges. West
of the divide, ground water discharges to the river; a gravel layer in the alluvium
acts as the major path of ground'^water flow to the river. The water table gradient
ranges from 0.006 to 0.08 ft/ft in the site area.
The ground-water velocities in this area vary as a function of the water table
gradient, hydraulic conductivity, effective porosity, and stage of the river and creek.
In the fine-grained alluvium and residual soils, ground-water velocities are a few
tenths of a foot per day. The residual sand- and gravel-size fragments allow
ground-water velocities of as much as five feet per day. In the weathered rock,
flow velocities vary depending on the extent of jointing, fracturing, and
weathering, [n situ.testing in bedrock well SP-1C revealed a velocity of less than 0.1
feet/day, although higher values might occur locally in fracture zones.
Hydraulic conductivities measured for the subsurface materials are reported in
Table 5-1 and summarized below:.
Bedrock - 5 x 10-7 to 4 x 10-6 cm/sec
Alluvium -6x 10-6to4x 10-3cm/sec
Residuum/Weathered rock - 4 x 10-5 to 4 x 10-* cm/sec
Residual sand- and coarse gravel-size fragments -1x10-2 cm/sec.
Figure 5-3 depicts the general water table contours for the site area and the
directions of local ground-water flow. Ground-water recharge for the site area is
derived mostly from local precipitation. However, some recharge occurs from the
unlined impoundments. Minor seasonal differences occur in water table contours
and flow direction. Section D in the Part B permit application contains more
detailed information on seasonal water table elevations, localized ground-water
flow around specific impoundments, and effects of bank storage.
Ground-water levels in the nested wells on both sides of both the river and the
creek indicate upward (discharging) gradients toward these surface water bodies.
5-6
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OSWER Directive 9481.00-11
TABLE 5-1. AQUIFER CHARACTERISTICS
Well
SP-1A
SP-18
SP-1C
SP-2
SP-3
SP-4A
SP-4B
SP-5
SP-6
SP-7
SP-8A
SP-8B
LF-1
LF-2
LF-3
LF-4
LF-5
LF-6
WQ-3
WQ-8
WQ-9
WQ-10
WQ-15
NW-1A
NW-1B
NW-2A
NW-2B
NW-3A
NW-3B
NW-4A
NW-48
NW-5A
NW-5B
MW-6A
MW-6B
NW-7A
NW-7B
NW-8A
NW-8B
NW-9A
NW-9B
NW-10A
NW-10B
NW-11A
NW-11B
NW-12A
NW-12B
Well Depth
-------
OSW E R Di recti ve 9481.00-11
FACILITY B
LEGEND
O SP Sariai Wall
LF Series Well (-
NW Nartad Wall
FIGURE 5-3. WATER TABLE CONTOURS
5-8
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OSWER Directive 9431 00-11
In addition, water quality in monitoring wells west of River A and east of Creek 8
shows no indication of contamination. Therefore, all the contaminated ground
water apparently flows into the river or creek, not under them. Details on ground-
water flow are presented in Section D of the Part B permit application.
Section B of the Part B permit application includes results of a reconnaissance
of the banks of both Creek B and River A. The study included observations of the
creek and river at four different times during a one-year period. Aerial
photographs were also utilized for the study. No seeps or springs were observed on
the banks of either water body.
5.4 Surface Water Hydrology
River A bounds the facility property on the west and flows to the southwest.
Creek B flows from east to southwest across the property and into River A at th€
southwest corner of the property. Figure 4-1 shows the location of the facility
relative to the creek and river.
The wastewater treatment area includes a number of basins used to retain
wastewater and storm overflow. These basins are situated on the western side of
the facility property, close to the east bank of the river, as depicted in Figure 4-1.
Only the effluent canal and the post-clarification polishing ponds are in the 100-
year floodplain of River A (see Section B and Plate 6 of the Part B permit
application). The canal's western side is diked and stabilized with rip rap to resist
flooding up to an elevation of 580 feet (575.5 feet is the expected elevation of the
100-year flood at this location). The polishing ponds are not diked but their
elevation is higher than 575.5 feet. In any event, flooding is not expected to present
a contamination problem because the water in both the effluent canal and the
polishing ponds is suitable for discharge given NPDES effluent limitations (described
in Appendix 2 of the Part B permit application).
Data show that the average flow for the river for the years 1968 through 1982
is more than 2800 cfs. The minimum average daily flow is 329 cfs, and the minimum
recorded instantaneous flow is 95 cfs. For the creek, 1.75 cfs is the average 7-day
low flow with a recurrence interval of 10 years. Flow data for the river and the
creek are presented in Section 8 of the PartB permit application.
5-9
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OSWER Directive 9481.00-11
6.0 EXPOSURE PATHWAYS
In this section, both human and ecosystem receptors are considered in an
analysis of potential exposure pathways. As shown in Section 5.3 of this application,
data indicate that all contaminatedground water will discharge to surface waters.
On the facility property, human-exposure to contaminated ground water is
currently prevented by restricting'the use of onsite wells. Until ground water meets
allowable exposure levels, these use restrictions will remain in effect. Therefore, all
likely exposure pathways to contaminants originating at Facility B are through the
surface waters of River A and Creek B.
Potential human exposures could be through direct ingestion of water or
direct ingestion of water and fish. For potential ecosystem exposure, water quality
criteria for aquatic life are used. Ecosystem and human allowable exposure levels
are presented and used to develop the maximum allowable exposure
concentrations for all five constituents for which this ACL application is being made,
6.1 Potential Human Exposure
All five constituents addressed in this application have been identified as
systemic toxicants. Detailed information on the toxic effects of these constituents
on humans is provided in Appendix B of this ACL application.
River A is a source of drinking water for City B. The intake is some ten miles
downstream of Facility B. None of the five constituents have been detected in the
intake to the water supply system of City B, perhaps because all five are volatile and
would leave the water column relatively quickly. Moreover, all five have hydrolysis
half-lives of less than 12 hours (EPA, 1979).
One of the constituents, p-dichlorobenzene, has a maximum contaminant
level (MCL) of 0.075 mg/1. Since the other four constituents do not have MCLs,
reference doses (RfDs) are used and have been provided in Table 6-1. Limits for
human exposure based on the reference doses (RfOs) have been calculated
assuming the ingestion of 2 I/day of drinking water by a 70 kg adult (EPA, 1987).
6-1
-------
NJ
TABLE 6-1.
ALLOWABLE SURFACE WATER EXPOSURE LEVELS
Chemical & CAS No.
Chlorobenzene
108-90-7
o-Oichlorobenzene
95-50-1
p-Dichlorobenzene
106-46-7
Ethylbenzene
100-41-4
Toluene
108-88-3
MCLHI
NA
NA
75
NA
NA
RfDUJ
0.03
0.09
0.09
0.1
0.3
Human Exposures!3!
Drinking
Water
(Eq. 6-1)
1,050
3,150
—16)
3,500
10,500
Drinking
Water and
Fish Ingestion
(Eq. 6-2)
1.015
2.670
2.670
3,120
10,150
Ecosystem Exposures!*)
Acute
250
1,120
1,120
32,000
17,500
Chronic
50
763
763
320
175
Maximum Allowable
Exposure
Concentration^)
50
' 7,63
75
320
175
[1] Maximum Contaminant Level, expressed in ug/l. NA = not available.
[2] Verified Reference Dose (RfD), mg/kg/day (EPA, 1986a)
[3] Based on RfD method, ug/l
[4] Based on Water Quality Criteria for 1986, ug/l (EPA, 1986b)
[5] The most protective exposure level tabulated for the specific hazardous constituent based on the various surface water
exposures, ug/l.
[6] MCL is used for drinking water exposure level.
st
m
30
O
i
o
O
-------
OSWER Directive 9481.00-11
The following general formula is used to calculate the allowable exposure
concentration (EPA, 1987):
Rf D x 70 kg
CRfD= (6-1)
2 I/day
where
C = Concentration, mg/l
RfD = Reference Dose, mg/kg/day
70 a Adult weight, kg
2 = Water intake, I/day.
Exposure through ingestion of contaminated fish can be quantified using the
bioconcentration factor and assuming that an adult would eat 6.5 grams of fish per
day (EPA, 1980a). The following equation is used to express the maximum
allowable surface water concentration (in mg/l) for exposure by drinking water and
ingesting fish:
RfD x 70 kg
CBCF= (6-2)
2 I/day + (0.0065 x BCF)
where
0.0065 a Fish intake, kg/day
BCF a Bioconcentration factor, I/kg.
The bioconcentration factors (BCFs) for fish, shown in Table 6-2, are taken from the
Ambient Water Quality Criteria documents (EPA, 1980b-e). The human exposure
levels calculated using both of the above equations are presented in Table 6-1.
6-3
-------
OSW E R Di recti ve 9481.00-11
TABLE 6-2.
BIOCONCENTRAT1ON FACTORS (BCF) FOR FISH
Constituent
Chlorobenzene
o-Dichlorobenzene .;
p-Dichlorobenzene
Ethylbenzene
Toluene
BCF (I/kg)
10.3
55.6
55.6
37.5
10.7
6.2
Potential Environmental Exposure
The ecosystems of River A and Creek B have been examined by a biologist
employed by the owners of Facility B. The biologist examined waters upstream and
downstream of the facility in both the river and the creek. Fish population data
from an earlier study, conducted at a lake that discharges into River A six miles
south of the facility, were used to supplement the study performed for this facility.
No ecological damage and no threatened or endangered species were identified in
either study. There are no known threatened or endangered species residing in the
area (FWS, 1985). Detailed results of the ecological study are reported in the Part B
permit application, Appendix 3.
EPA water quality criteria (EPA, 1980b-e) for the protection of aquatic life are
shown in Table 6-1. Both acute and chronic exposure levels are provided. For
ethylbenzene and toluene, an acute/chronic ratio of 100 is assumed to derive
chronic exposure levels (EPA, 1985).
6.3
Maximum Allowable Exposure Concentrations
Table 6-1 contains the MCL and RfD-based allowable drinking water exposure
levels, the acute and chronic water quality criteria for the protection of aquatic life,
6-4
-------
OSWER Directive 9481 00-1!
and the RfD-based allowable exposure level for drinking water and fish mgestion
The maximum allowable exposure concentrations in the surface waters adjacent to
the facility were determined basecl on the most vulnerable receptor, human or
environmental. The MCI value was used as the human receptor value where
available (i.e., for p-dichloroben/ene) For the other constituents, the RfD based
allowable exposure level for drinking water and fish mgestion was used This
human receptor value was then compared to the chronic ecosystem exposure value,
and the lower of the two was selected as the maximum allowable exposure
concentration. For p-dichlorobenzene, the lowest criteria is the MCL, for the other
four constituents, the chronic ecosystem exposure level is applicable
6-5
-------
OWSER Directive 9481 00-11
7.0 DEVELOPMENT OF ACLs
The maximum allowable exposure concentrations for thtorobenzene, o-
dichlorobenzene, p-dichlorobenzene, ethylbenzene and toluene were presented tn
Table 6-1, As noted in Section 6, these concentrations were developed by assuming
that all exposures would be from River A and Creek 8 The exposure pathways
considered were human ingestion of drinking water, human mgestion of drinking
water and fish, and water quality criteria for aquatic life Ground-water pathways
were not considered because all the ground-water contamination discharges to the
surface water bodies (see Section 5,3) and because the facility will prohibit the
exploitation of ground water on tts property
7.1 Statistical Analysis of Surface Water Concentrations
Part I of the ACL Guidance Document states that ACLs may be established
based on contaminant discharge into a surface water body. This is allowable only
where the contaminant plume has already reached the surface water body and the
constituents do not cause a statistically significant increase in contaminant levels
over background in the surface water. That is, after accounting for the inherent
variation in the sampling and analysis data, the release of a constituent into a
surface water body should not cause an increase in the background surface water
concentration of that constituent.
Surface water samples are to be collected in the discharge zone of the ground-
water contaminant plume. If, upon sampling in the discharge zone, the levels of the
constituent of concern are not detectable, a statistical comparison of sampling data
need not be performed (EPA, 1987). Since several constituents were detected in
some River A samples (Table 3-2), upstream and downstream constituent
concentrations in the surface water body were statistically compared. It should be
noted, however, that all the constituents detected in the surface water samples
were found at levels that did not exceed the maximum allowable concentrations in
Table 6-1,
Surface water and bottom sediment were sampled during periods in which the
flow of River A approximated the mean flow for the season during which sampling
was performed. River A flow data, both historic and during sampling, and all
7-1
-------
OWSER Directive 9481 00-11
monitoring data for the 13 sampling periods were submitted m Section D of the Part
8 permit application. The data for the 13 quarterly analyses for the three hazardous
constituents detected in River A water (chlorobenzene, o-dichlorobenzene. and
ethylbenzene) and sediment (chlorobenzene only) samples were evaluated for
statistical differences. Several statistical techniques were employed, descriptive
statistics are reported in Tables 7-1 through 7-3 and m Appendix C
Histogram and probability plots of these data showed that the constituents at
each sampling station are not normally distributed A goodness of f-t test
confirmed these observations. The data are not normally distributed because of the
effects of the large number of observations with concentrations below detectable
limits. For example, all observed concentrations of o-dichlorobenzene and
ethylbenzene m river water samples at stations SW-1, SW-3, and SW-4 are below
their respective detection limits.
Because there were so many non-detect values in the data for o-
dichlorobenzene and ethylbenzene, a test of proportions was used to compare the
proportion of non-detect values m the upgradient data to that in the downgradient
data for thess constituents. This technique relies on a bmomial test with a normal
approximation to compare the proportions. The summary statistics for this test are
provided in Table 7-3; the calculations are contained in Appendix C. As can be seen
by comparing the test statistics to the 2 statistic at the 0.05 confidence level (1.645),
there was not a significant trend in the proportion of non-detect values between
upgradient and downgradient samples for any of the compounds. Because of the
large number of non-detect values (>88%) m the data, this test demonstrates that
there is no significant increase in contamination in the river or creek resulting from
the contaminant plumes.
A second test, the nonparametnc (distribution free) Mann-Whitney Test, was
also used to examine the statistical difference between sampling stations.
According to Hintze (1987), when the number of samples per station are equal, as in
this demonstration, the Mann-Whitney Test is the most powerful nonparametric
procedure that can be used.
The Mann-Whitney Test is the nonparametric analog of the two independent
sample Student's t-test (Pfaffenberger and Patterson, 1977), and can be used m this
7-2
-------
OWSER Directive 9481 00-11
TABLE 7-1.
SUMMARY STATISTICS FOR WATER SAMPLES
Water Sampling
Station
Chlorobenzene
SW-1
SW-2
SW-3
SW-4
SW-5
o-Dichlorobenzene
SW-1
SW-2
SW-3
SW-4
SW-5
Ethylbenzene
SW-1
SW-2
SW-3
SW-4
SW-S
Mean
(vg<')
12
13
19
14
19
5
6
5
5
7
3
5
3
3
4
Standard
Deviation
(ug/D
10
11
14
10
15
0
3
0
0
5
0
6
0
0
2
1
95% Confidence Limit
Lower
bg/i)
6
6
11
8
10
5
5
-
1
-
-
3
Upper
(ug/l)
18
19
28
20
28
-
8
-
10
-
8
-
-
5
7-3
-------
OWSES Directive 9481 00-11
TABLE 7-2
SUMMARY STATISTICS FOR SEDIMENT SAMPLES--CHLOROBENZENE
Sediment
Sampling
Station*
SW-1
SW-2
SW-3
SW-4
SW-5
Mean
Cug/kg)
3
3
;
4
4
Standard
Devation
(pg/kg)
0
0
10
3
2
9S5o Confidence Limit
Lower
fug/kg)
--
2
2
2
Upper
tug/kg*
--
--
13
6
5
7-4
-------
OWSER Directive 9481 00-11
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7-5
-------
OWSER Directive 9481 00-11
demonstration to test the difference oetween the mean, of the n«er fwater and
sediment) samples on a pairwsse basis, as the following assumptions regarding *he
test are met
• Both sets of data contain random samples,
• There is independence among the observationsfsamples),
• The data are continuous, and
» The measurement scale is at least ordinal
Using the Mann-Whitney Test procedure, the concentration measured in
either the water or sediment at each of the five sampling stations was compared to
the other four stations to determine if the mean concentration of a given
constituent at the downstream station of the pair was significantly greater than the
mean at the upstream station In order to perform this test, a value of one-half the
limit of detection was used to represent the concentrations of constituents not
detected m a sample. The test statistic U was calculated and compared to the
tabulated critical value W at the desired significance level a and the appropriate
number of samples m and n, where m is the number of samples at the upstream
station and n is the number of samples at the downstream station A significant
increase in mean concentration from the upstream station to the downstream
station is shown if:
• U > Wla^.m.n.] Or
• U < (mn-W(a/2,m.n]).
For example, for the comparison of chforobenzene concentrations in water
samples obtained 3tSW-l and SW-3, the test statistic U is 55 (see Appendix C) The
critical value W, for a = 0,05, m = 13, and n = l3, is 41. The test statistic U is
compared to the critical values W as shown below (see Pfaffenberger and Patterson,
1977; p. 673 and Table 11):
U = 56 < {(13 x 13)-(W[0.025. 13. 12) = 41)} = 128
7-6
-------
OWSER Directive 9481 00-n
Results of this example show that no significant increase m chforoben/eie
concentration was observed between SW-1 and SW 3
The results of similar tests performed for all constituents detected m both
water and sediment samples indicate no statistically significant increase m mean
constituent concentration *rom upstream to downstream sampling stations
Results obtained by Mann-Whitney testing are supported by the results
obtained with Steel's Many-One Rank Test (Milter, 1966) These results are
presented in Appendix C The Steel's Many-One Rank Test, like the Mann-Whitney
Test, is a nonparametnc test and does not assume the data to be normally
distributed as does its Student's t-test counterpart. Further, for non-normal
distributions, it will be more appropriate than the t-Test (Hodges and Lenmann,
1956). Steel's Test can be used to determine if contamination at the downstream
sampling stat»ons, SW-2 through SW-5, is significantly greater than at the upstream
station SW-1 Tests for both water and sediment samples show that none of the
stations exhibit contaminant concentrations significantly greater than observed at
SW-1.
7.2 Proposed ACLs
Because none of the constituents caused statistically significant increases
above background m the surface water bodies, the ACLs are proposed at the current
concentrations m the POC wells or the maximum allowable concentrations from
Table 6-1, whichever is higher. No attenuation in the ground water was considered
since the POC is adjacent to the nver. The ACLs proposed for chlorobenzene, o-
dichlorobenzene, and p-dichlorobenzene are the concentrations currently observed
m the compliance monitoring wells at the POC {discussed in Section 8). The
proposed ACLs for ethyl benzene and toluene are based on the maximum allowable
concentrations from Table 6-1. Proposed ACL concentrations are presented in Table
7-4.
The rationale for the proposed ACLs is as follows:
« No potential for exposure to contaminated ground water exists since all
contammant$ discharge to the surface water bodies (River A and Creek
7 7
-------
OWSER Directive 9481 00-11
B), and exploitation of the ground water will not be permitted at the
faality
No contaminant attains statistically significant levels above background
in either River A and Creek 8
Alt constituents in River A and Creek B are well below their maximum
allowable surface water concentrations as derived m Section 6 and
shown in Table 6-1
Contaminant levels in the ground water have been decreasing
For those constituents (chlorobenzene, o-dichlorobenzene, and p-
dichlorobenzene) above the maximum allowable surface water
concentrations in the ground water, the proposed ACLs are the current
levels in the POC wells.
For those constituents (ethylbenzene and toluene) that have not reached
the allowable surface water levels in the POC wells, the proposed ACLs
are the allowable surface water levels.
TABLE 7-4.
PROPOSED ALTERNATE CONCENTRATION LIMITS
Chemical
Chlorobenzene
o-Oichlorobenzene
p-Oichlorobenzene
Ethylbenzene
Toluene
ACLs (ng/l)
260
1,040
350
320
175
7-8
-------
QSWER Direct,ve948t 00-''
8.0 MONITORING PROGRAM
8.1 Ground-Water Monitoring
Compliance monitoring of ground-water quality downgradient of the
impoundments has been implemented through the installation of nine new
compliance wells and the use of ten existing wells. These wells are shown on Figure
8-1. Wells on the western side of the regulated units constitute the compliance
point for ground-water flow to the river, and wells on the eastern side constitute
the compliance point for flow to the creek. The compliance wells will be sampled
quarterly until the units undergo sjccessful clean closure according to the
requirements in §264.228. As indicated in Table 3-1, concentration levels of aM five
contaminants have been decreasing with time. Ground-water monitoring will
determine the extent of this decrease The compliance monitoring program must
also ensure that the individual constituent ACLs are met.
8.2 Surface Water Monitoring
As part of Facility B's ACL application (and described in more detail in Section F
of the Part B permit application), surface water sampling w»l! continue, Sampling
points will be those used previously (see Figure 3-5) To determine statistical
significance, samples will be taken four times a year during times that stream flow is
near the seasonal average.
8-1
-------
OSWE* Directive 94fli 00-'
LEGEND
Compliance Wells
A CW Series
• LF Series
O SP Series
WQ Series
FIGURE 8-1. COMPLIANCE WELL LOCATIONS
8-2
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OSWER Directive 9481 00-11
REFERENCES
Community B Engineer's Office, 1987 Water Treatment Data (unpublished)
EPA (U.S. Environmental Protection Agency), 1979. Water Related Fate of 129
Priority Pollutants. Vol.1 - Introduction and Technical Background. Metals
and Inorganics, Pesticides and PCBs; EPA/440-4-79-029a, Washington, DC,
December.
EPA (U.S. Environmental Protection Agency), 1980a, "Ambient Water Quality
Criteria Documents; Availability," Federal Register, 45:79318-79357,
November.
EPA (U.S. Environmental Protection Agency), 1980b. Ambient Water Quality
Criteria for Chlorinated Benzenes, EPA/440-5-80-028, Washington, D.C.,
October.
EPA (U.S. Environmental Protection Agency), 1980c. Ambient Water Quality
Criteria for Dichlorobenzenes, EPA/440-5-80-039, Washington, D.C, October.
EPA (U.S Environmental Protection Agency), 1980d. Ambient Water Quality
Criteria for Ethylbenzene, EPA/440-5-80-048, Washington, D.C., October.
EPA (U.S. Environmental Protection Agency), 1980e. Ambient Water Quality
Criteria for Toluene, EPA/440-5-80-075, Washington, DC, October.
EPA (U.S. Environmental Protection Agency), 1985. Technical Support
Document for Water Quality-Based Toxics Control. EPA/440-4-85-032,
Washington, D.C., September.
EPA {U.S. Environmental Protection Agency), 1986a. Research and Hevelopment,
Verified Reference Doses (RfDs) of the U.S. EPA, ECAO-CIN-475, Environmental
Criteria and Assessment Office, Cincinnati, Ohio, January.
R-1
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O5WER Directive 9481 00-11
EPA (U.S. Environmental Protection Agency), 1986b Quality Criteria for
Water,1986* EPA/440-5-86-001, Washington, D C , May 1
EPA (US. Environmental Protection Agency), 1986c RCRA Ground-Water
Monitoring Technical Enforcement Guidance Document (TEGD), OSWER-
9950.1, Washington, D.C., September
EPA (U.S. Environmental Protection Agency), 1987. Alternate Concentration
Limit Guidance: Part 1 - ACL Policy and Information Requirements. EPA/530-
SW-87-017, Office of Solid Waste, Washington, D.C., July.
FWS (U S, Fish and Wildlife Service), 1985. Summary of Endangered and
Threatened Species in the Vicinity of Facility B, Memo Report.
Hintze, Jerry L, 1987. Number Cruncher Statistical System, Version 5.0, Dr Jerry L.
Hintze, Kaysville, Utah.
Hodges, J, L., Jr., and E L, Lehmann, 1956. "The efficiency of some nonparametric
competitors of the t-Test", Ann. Math. Statist., Vol 27, pp. 324-335
Pfaffenberger, R. C., and J. H. Patterson, 1977. Statistical Methods for Business and
Economics, Richard D Irwin, Inc., Homewood, Illinois, pp. 672-675, Table 11.
Sokal, R, R., and F. J. Rohlf, 1969. Biometry, The Principals and Practice of Statistics
in Biological Research, W. H. Freeman and Company, San Francisco.
Chapter 13.
Other Resource Documents
Bear, J., Hydraulics of Ground Water, McGraw-Hill, New York, New York, 1979.
Brown, M.S., D.R. Bishop, and C.A. Rowan, "The Rote of Skin Absorption as a
Route Exposure for Volatile Organic Compounds (VOCs) in Drinking
Water," American Journal of Public Health, 74(s)479-484, May, 1984.
R-2
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OSWER Directive 9481 00-1
Freeze, R- A., and J. A. Cherry, Groundwater, Prentice-Hail, Inc., Englewood
Cliffs, New Jersey, 1979
Kulthau, R. and G Faust, RCRA Permit Writer's Guidance Manual•-Ground-Water_
Protection, U.S. Environmental Protection Agency, W?jhmgton, D C , 1983
Miller, R. G., Jr., Simultaneous Statistical Inference. McGraw-Hill Book Company,
New York, 1966, pp. U3-153.
Zoetman, B. C., E. Degrees, and S. J. J. Brinkman, "Resistancy of Organic
Contaminants in Ground Water, Lessons from Soil Pollution in the
Netherlands," Science of the Total Environment, 21 (81); 187-202, Eleventh
Scientific Publishing Company, Amsterdam, Netherlands, 1982.
R-3
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OSWE3 Directive 9«ia-
APPENDIX A
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
§264,94(b}(1) AND §264.94{b){2)
A-1
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OSWE* D-'ect've 958'
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITf RIA
Criteria for Assessing Potential Adverse Effects on
Ground-Water Quality: ACL Case Study
§264,94{b)(1) Sect.onNo
.0 The physical and chemical characteristics of the 31,32
waste in the regulated unit, including its
potential for migration,
in) The hydrogeological characteristics of the 51,52,5'
facility and surrounding land,
(in) The quantity of ground water and the direction 53
of ground-water flow;
(iv) The proximity and withdrawl rates of ground- 4.2
water users;
(v) The current and future uses of ground water in 4,1,4.2
the area;
(vi) The existing quality of ground water, including 32
other sources of contamination and their
cumulative impact on the ground-water
quality,
.VM) The potential for health risks caused by human 6.1,6.3
exposure to waste constituents,
ivin) The potential damage to wildlife, crops, 6.2,6.3
vegetation, and physical structures caused by
exposure to waste constituents,
(ix) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects
A 2
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OSWER Directive 9481 00-
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
(Continued)
Criteria for Assessing Potential Adverse Effects on
Hydraulically-Connected Surface-Water Quality: ACL Case Study
§264.94{b){2) Section No.
(i) The volume and physical and chemical 31,12
characteristics of the waste m the regulated
unit,
The hydrogeological characteristics of the 5.1,5,2, 53,54
facility andsurroundmg land,
The quantity and quality of ground water, and 5.3, 54
thedirectton of ground-water flow,
(iv) The patterns of rainfall m the region; 4.3
(v) The proximity of the regulated unit to surface 4,2
waters,
(vi) The current and future uses of surface waters m 4.1,4,2
the area and any water quality standards
established for those surface water;
(vii) The existing quality of surface water, including 3,2
other sources of contamination and the
cumulative impact on surface water quality,
(viii) The potential for health risks caused by human 6.1,6.3
exposure to waste constituents,
(ix) The potential damage to wildlife, crops, 6.2,6.3
vegetation, and physical structures caused by
exposure to waste constituents, and
(x) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects.
A-3
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OSWeR Directive 9481 00-
APPENDIXB
CHEMICAL AND PHYSICAL PROPERTIES
QFCHLORO8ENZENE, DICHLOROBENZENES,
ETHYLBENZENE, AND TOLUENE^
AND
IRIS.
(INTEGRATED RISK INFORMATION SYSTEM)
DATA BASE FOR ETHYLBENZENE AND TOLUENE
'Adapted from: Chemical, Physical and Biological Properties of Compounds Present
at Hazardous Waste Sites, final Report, Office of Waste Programs Enforcement
(OWPE) and Office of Solid Waste and Emergency Response (OSWER), U.S. EPA,
September 27, 1985
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OSWER Directive 948i 00-H
CHEMICAL AND PHYSICAL PROPERTIES OF
CHLOROBENZENE
Summary
Chlorobenzene is used as a solvent and as a raw material in chermta!
manufacturing. It is persistent m the environment and can be jdsorbed to organic
material in soil, Chlorobenzene may cause liver tumors m male mice Animals
exposed to Chlorobenzene have exhibited liver and kidney damage Chlorobenzene
is not very toxic to aquatic organisms; none of the LCsc values are less than 10
mg/liter.
CAS Number: 108-90-7
Chemical Formula: CeHsCi
lUPACIMame: Chiorobenzene
Important Synonyms and Trade Names: Monochlorobenzene, benzene chloride,
phenyl chloride
Chemical and Physical Properties
Molecular Weight: 112.6
Boiling Point: 131°C
Melting Point: -46°C
Specific Gravity: 1.11 at 20°C (liquid)
Solubility in Water: 500 mg/l
Solubility in Organics: Soluble in alcohol, benzene, chloroform, ether, and
carbon tetrachloride
Vapor Pressure: 8.8 mm Hg at 20°C
Vapor Density: 3.88
Henry's Law Constant: 3.56 x 10-3 atm m3/mole at 25"C.
Flash Point: 28°C
Log Octanol/Water Partition Coefficient: 2.83
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OSWER Directive 948' 00-''
Health Effects
A study of the carcmogeniaty of chlorobenzene was recently completed by
the National Toxicology Program and preliminary results show that chlorobenzene
caused neoplastic nodules in the liver of male rates but was not carcinogenic m
female rates or in mice.
C .cupational studies suggest that chronic exposure to monochiorobenzene
vapor may cause dyscrasia, hyperlipiderrua, and cardiac dysfunction in humans Like
many organic solvents, monochlorobenzene is a central nervous system deprc^ant
in overexposed humans, but no chronic neutrotoxic effects have been reported
Animals exposed to chlorobenzene have exhibited liver and kidney damage and
atrophy of the seminiferous tubules in the testes. The oral LDso value for rates was
2910mg/kg.
Toxicity to Wildlife and Domestic Animals
Chlorobenzene was acutely toxic to fish at levels greater than 25 mg/liter and
to aquatic invertebrates at levels greater than 10 mg/liter No chronic studies on the
toxicity of chlorobenzene to aquatic life were found m the literature reviewed.
Monochlorobenzene was shown to have a bioa^cumulation factor of about 1,000 in
freshwater species. No studies on terrestrial wildlife or domestic animals were
reported in the literature reviewed.
Standards and Criteria
RfD: 0.03 mg/kg/day
RfD: 1.0mg/l
Ambient Water Quality Criteria (U.S. EPA);
Aquatic Life
The available data are not adequate for establishing criteria. However, EPA
did report the lowest concentrations of chlorobenzens known to be toxic in
aquatic organisms, also known as the lowest effect level (LEL).
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OSWER Directive 9481 00-
Freshwater
Acute toxicity:
Chronic toxicity:
Marine
Acute toxicity:
Chronic toxicity:
Human__Healt_h
Water and Fish Ingestion:
Fish Ingestion Only:
250ug/liter(LEL)
50ug/hter(LEL)
16Qug/liter(LEU
129ug/liter(LEL)
488 ug/iiter
Not available
Others
OSHA Standards (air):
ACGIH Threshold Limit Value:
350mg/m3TWA
1,120 mg/m3 Ceiling Level
350 mg m3TWA
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OSWER Directive 9
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QSWE3 Directive
00- 1
CHEMICAL AND PHYSICAL PROPERTIES OF
DICHLOROBENZENES
Summary
CAS Number: 1,2-Dichlorobenzene (1,2-DCB) 95-50-1
1,3-Dichlorobenzene(1,3-DC8) 541-73-1
1,4-Dichlorobenzene(l,4-DCB) 106-46-7
Chemical Formula: CsmCij
lUPACName: Dkhlorobenzene
important Synonyms and Trade Names: o-Dichforobenzene (1,2-DCB) 95-50-1
m-Dichlorobenzene (1,3-DC8),
p-Dichlorobenzene (1,4-DCB)
Chemical and Physical Properties
Molecular Weight:
Boiling Point:
Melting Point:
Specific Gravity;
Solubility in Water:
Solubility in Organics:
Vapor Pressure:
Vapor Density:
Henry's Law Constant:
Flash Point:
147,01
1,2-DCB: 180.5°C
1,3-DCB: 173°C
1,4-DCB: 173°C
1,2-DCB: -17.0X
1,3-DCB: -24°C
1,4-DCB: -53°C
1 3at20°C
1,2-DCB: 145mg/!iterat25°C
1,3-DCB: 123mg/literat25°C
1,4-DCB: 80mg/literat25°C
Soluble in alcohol, ether, acetone, benzene, carbon
tetrachlonde, and Itgroin
1mm Hgat20°C
5.05
1.99x 10-3atmm3/mo!e
71X
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OSWER Directive 948' 00- M
Log Octanol/Water Partition Coefficient 3 38
Health Effects
It is generally thought that the available data are inadequate for assessing the
carcinogenic potential of DCS in animals and humans One case study suggests an
association between exposure to dichlorobenzene and several cases of leukemia
DCB is reported to be nonmutagenic in Salmonella typhimunum tester strains
Mutagenic ?nd clastogenic activity reportedly occurs in some plant test systems Mo
data are available for evaluating the tetratogemc or reproductive effects m animals
or humans.
Symptoms of acute inhalation intoxication m humans include headache,
nausea, and throat irritation. DCS is also a skin and eye irritant. A variety of other
symptoms, including weakness, fatigue, and anemia, have been observed after
chronic dermal and inhalation exposure to dichlorobenzene.
Inhalation of OCB causes eye and upper respiratory tract irritation, central
nervous system depression, and liver and kidney damage in experimental animals.
An LCio of approximately 4,900 mg/m3/7 hours is reported for the rat. No toxic
effects were observed after daily 7-hour inhalation exposures of up to 560 mg/m3
for as much as 7 months in several species of experimental animals. Hepatic
porphyria is reported to occur in rats after daily trachea! intubation of 455 mg/m3
for up to 15 days. Oral exposure results in stimulation of liver microsomal enzyme
systems and cumulative toxicity. The oral LDsrj for the rate is 500 rng/kg. Chronic
oral exposure to 188 mg/kg/day causes liver and kidney damage in rats. Exposure to
0.01-0.1 mg/kg/day produces changes in the hematopoietic system, increased
prothrombin time, and altered conditioned reflexes and enzyme activities in
chronically exposed rats. In general, toxicity increases in the order 1,4-DCB, 1,3-DCB,
1,2-DCB.
Toxicity to Wildlife and Domestic Animals
The 48-hour and S5-hour LCso values for Oaphnia and bluegills, respectively,
tested under static conditions, were 2,440 and 5.590 ug/liter (1,2-DCB); 28,100 and
5,020 ug/liter (1,3-DCB); and 11,00 and 4,280 ug/liter (1,4-DCB). Two flow through
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OSWER Directive 9481 00-' '
96-hour LCso tests using fathead minnows and rainbow trout gave values of about
3,000 ug/liter ts reported for the fathead minnow Acute values for three saltwater
species ranged from 1,970 ug/liter for the mysid shrimp to 9,660 ug liter for the
sheephead mmnow. No saltwater chronic values are available A whole body
bioconcentration factor of about <50 is reported for the bluegill
The 96-hour median effect levels for chlorophyll a and cell number are 179,000
and 149,000 ug/liter, respectively, in the freshwater alga Selenastrum
capricornutum In the saltwater alga Skeletonema constatum the corresponding
values are 44,200 and 44,100 ug/liter, respectively.
Standards and Criteria
National Primary Drinking Water Standard (U.S. EPA}:
1,4-DCB MCL: 75 ug/l
1,2-DCB RfD: 0.09 mg/kg/day
RfD: 3.0 ug/l
Ambient Water Quality Criteria (u.S EPA):
Aquatic Life
The available data are not adequate for establishing some criteria. However,
EPA did report the lowest concentration of chtorobenzene known to be toxic
in aquatic organisms, also known as the lowest effective level (LEL).
Freshwater
Acucetoxicity: 1120 ug/liter (LEL)
Chronic toxicity: 763 ug/fiter (LEL)
8-8
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OS WE R Directive 948t 00-ti
Marine
Acute toxicity:
Chronic toxicity
l970ug/l»ter(LEL)
not available
Human Health
Water and Fish Ingestion, 400 ug/Nter
Fish Ingestion only: 2.6 mg/liter
Human Health
Others
OSHA Standard:
ACGIH Threshold Limit Values:
300 mg/m3 Ceiling Level
300 mg/rr)3 Ceiling Level
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OSWER Directive 948' 00-11
RESOURCE DOCUMENTS FOR DICHLOROBENZENE
American Conference of Governmental Industrial Hygiemsts, Documentation of
the Threshold Limit Values, 4th ed., Cincinnati, Ohio, 1980,488 p
International Agency for Research on Cancer, "Some Industrial Chemicals and
Oyestuffs," [ARC Monographs on the Evaluation of.the Carcinogenic Risk of
Chemicals to Humans, Vol. 29, World Health Organization, Lyon, France, 1982,
pp. 213-238.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base, Washington, D.C., October, 1983
Sax, N.I., Dangerous Properties of Industrial Materials, 4th ed., Van Nostrand
Reinhold Co., New York, New York 1975, 1,258 p.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Dichlorobenzenes, EPA/440-5-80-039, Washington, D.C.,October, 1980.
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants, EPA/44Q-4-79-Q29a and b, Washington, O.C., December,
1979.
Weast, R.E., ed., Handbook of Chemistry and Physics, 62nd ed., CRC Press, Cleveland,
Ohio, 1581,2,332p.
6-10
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OSWER Directive 9481 00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
ETHYL8ENZENE
Summary
CAS Number: 100-41-4
Chemical Formula: CgHsC2H5
IDPACName: Ethylbenzene
Important Synonyms and Trade Names Phenyfethane, £B, ethylbenzol
Chemical and physical Properties
Molecular Weight: 106.2
Boiling Point: 136.2°C
Melting Point: -95°C
Specific Gravity 0.867 at 20°C (liquid)
Solubility in Water: 161 mg/literat 25°C
Solubility in Organic* Freely soluble in organic solvents
Vapor Pressure. 7mmHgat20°C
Vapor Density: 3.66
Henry's Law Constant: 6.44 atm, m3/mole
Flashpoint: 17.2°C
Log Octanol/Water partition Coefficient: 3,15
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OSWER Directive 9481 00-
Transport and Fate
Only limited data are available on the transport and fate of ethyibenzene
Volatilization is probably the major route of elimination from surface water
Subsequent atmospheric reactions, especially photooxidation, are responsible for its
fate. However, its high log octanol/water partition coefficient suggests that a
significant amount cf ethyibenzene may be adsorbed by organic material in the
sediment. Some soil bacteria are capable of using ethyibenzene as a source of
carbon. However, the relative importance of this potential route of ethyibenzene
elimination has not been determined.
Standards and Criteria
RfO: 0.1 mg/kg/day
Ambient Water Quality Criteria (US EPA):
Refer to IRIS Data Base
Others
OSHA Standard (skin): 435mg/m3TWA
ACGIH Threshold Limit Values: 435 mg/m3
545mg/m3$TEL
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OSWER Directive 9481 00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS) Chemical Files
Ethylbenzene, CAS No 100-41-4 (Revised 11/16/1986)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included m IRIS only after a
comprehensive review of chronic toxicity data by work groups composed of U S
EPA scientists from several Agency Program Offices. The summaries presented tn
Sections I and It represent a consensus reached in those reviews The con entual
bases of these risk assessments are described in Appendicts A & 8 m Service Code 4
The other sections are supplementary information which may be useful m
particular risk management situations, but have not yet undergone comprehensive
U.S. EPA review. The risk management numbers (Section V) may not be based on
the most current risk assessment, or may be based on a current, but unreviewed,
risk assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. Fora
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4
STATUS OF DATA FOR Ethylfcenzene
I. Chronic Systemic Toxicity: Noncarcinogenic Health Effects
A. OralRfD: available
8. Inhalation RfD: none
II. Risk Estimates for Carcinogens: none
IU. Drinking Water Health Advisories: none
IV. Kisk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogen icity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed fora lifetime. RfDscan also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481 00-1'
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical Ethylbenzene
CAS No.. 100-41-4 Preparation Date 01/09/86
1 REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Liver and kidney NOEL 136 mg/kg/day 1000 1 1E-1
toxicity mg/kg/day
LOAEl: 408 mg/ kg/day
Ratsubchronic to
chronic oral bio-
assay
Wolf etal. (1956)
* Dose Conversion Factors & Assumptions: 5 days/7 days, thus, 136 mg/kg/day
x 5 days/7 days = 97.1 mg/kg/day
2 PRINCIPAL AND SUPPORTING STUDIES
Wolf, M.A., V.K. Rowe, D.D McCollister, R.L. Hollingsworth and F. Oyen.1956.
Toxicologiral studies of certain alkylated benzenes and benzene. Arch. Ind. Health.
14: 387-398.
The chosen study is a rat 182-day oral bioassay in which ethylbenzene was
given 5 days/week at doses of 13.6, 136,408 or 680 rng/kg/day in olive oilgavage.
There were 10 albino female rats/dose group and 20 controls.
The criteria considered in judging the toxic effects on the test animals were
growth, mortality, appearance and benavior, hematological findings, terminal
concentration of urea nitrogen in the blood, final average organ and body weights,
histopathological findings, and bone marrow counts. The LOAEL of 408 mg/kg/day
is associated with histopathological changes in liver and kidney.
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OSWER Directive 9481 00-1'
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 1000 The uncertainty factor of 1000 reflects 10 for both tntraspeaes and
mterspecies variability to the toxicity of this chemical in lieu of specific data, and 10
for extrapolation of a subchronic effect level to its chrome equivalent
MF = 1
4 ADDITIONAL COMMENTS
None
5 CONFIDENCE IN THE RfD
Study: Low Data Base: Low RfD: Low
Confidence in the chosen study is low because rats of only one iex were tested
and the experiment was not of chronic duration. Confidence in the supporting data
base is low because other orai toxicity data were not found,A low confidence in the
RfD follows.
6. DOCUMENTATION AND REVIEW
A recent ORD document reaffirms the ADf from the ODW criteria document. Both
documents have had extensive Agency review, with the help of selected outside
scientists.
An identical ADI was publicly reviewed during the 1980 Ambient Water Quality
Criteria series
U.S. EPA. 1980 Ambient Water Quality Criteria for Ethylbenzene. Environmental
Criteria and Assessment Office, Cincinnati, OH. EPA 440/5-80-048.
U.S. EPA. 1985. Drinking Water Criteria Document for Ethylbenzene. Office of
Drinking Water, Washington, DC. (Public review draft)
U.S. EPA. 1985. Health Effects Assessment for Ethyldenzene. Environmental
Criteria and Assessment Office, Cincinnati, OH. ECAO-CIN-H008.
Agency RfD Work Group Review: 05/20/85
Verification Date: 05/20/85
8-15
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QSWER Directive 9481 00-
7 U.S. EPA CONTACTS
Primary fvll Dourson FTS/684-7544 or 513,569 7544
Office of Research and Development
Secondary CT DeRosa FTS/684-7534 or 513/569 7534
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Ethylbenzene
CAS No. 100-41-4
Information is not available at this time
I). RISK ESTIMATES FOR CARCINOGENS
Chemical: Ethylbenzene
CAS No: 100-41-4
This chemical has not been evaluated by the US. EPA for evidence of human
carcinogenic potential
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Ethy'benzene
CAS No.: 100-41-4
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical: Ethylbenzene
CAS No.: 100-41-4 Preparation Date: 08/28/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (m sections I & II), as this may explain apparent inconsistencies. Also
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OSWER Directive 9481 00-M
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility Such considerations are indicated m
the table below (Considers Econ/Tech Feasibility) Please direct any questions you
may have concerning the use of risk assessment information m makmg 3 risk
management decision to the contact listed m Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E m Service Code 4
A. RISK MANAGEMENT ACTIONS
Risk
Management
Action
Reportable
Quantity (RQ)
Status
Date
Final
1985
Risk
Management
Value
1000lbs
Considers
Econ/Tech
Feasibility
no
Reference
50 FR 13456
04/04/85
Water Quality
Criteria (WQC):
a. Human Health
b- Aquatic Toxicity
1} Freshwater
2) Marine
Final
198C
Final
1980
Final
1980
1.4mg/l
no
Acute no
32,000 ug/l (LED
Chronic
none
Acute no
430 ug/l (LEL)
Chronic
none
45 FR 79318
11/28/80
tbid.
ibid.
8. RISK MANAGEMENT RATIONALE
RQ
The final RQ is based on aquatic toxicity, as established under Section 311(b)(4)
of the Clean Water Act, and ignitability Available data indicates that the aquatic
96-Hour Median Threshold Limit for ethylbenzene is between 10 and 100 ppm. The
closed cup flash point is less than 100 degrees F and the boiling point is greater than
100 degrees F.
Contact; RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
B-17
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OSWEft Direct.ve 9*8' 00-' '
woe
Contact Office of Water Regulations and Standards
202-382-5400 or FTS-382-5400
a Human health The WQC of 1 4 mg/l is based on consumption of
contaminated aquatic organisms and water A WQC of 3 28 mg/l has also been
established based on consumption of contaminated aquatic organisms alone
b Aquatic toxicity: Water quality criteria for the protection of aquatic Me are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The "(LED" after the value indicates that the minimum data were not
available and the concentration given is not a criteria value but the lowest effect
level found in the literature.
V. SUPPLEMENTARY DATA
Chemical: Ethylbenzene
CAS No.: 100-41-4
Information is not available at this time.
Synonyms AETHYLBENZOL (German), EB, ETHYLBENZEEN (Dutch), ETHYL
BENZENE, ETHYLBENZOL, ETILBENZENE (Italian), ETYLOBENZEN (Polish), NCI-
C56393, PHENYLETHANE, UN 1175
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OSWER Directive 9481 00-11
RESOURCE DOCUMENTS FOR ETHYLBENZENE
American Conference of Governmental Industrial Hygienists, Do cum e n t a 11 o P g 11 he
Threshold Limit Values, 4th ed., Cincinnati, Ohio, 1980,488 p
American Industrial Hygiene Association, Hygienic Guide Series-Ethylbenzene,
AIHA, Akron, Ohio, 1978.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base, Washington, D C , October, 1983
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Ethylbenzene, EPA/440-S-80-048, Office of Water Regulations and Standards,
Criteria and Standards D vision, Washington, O.C., October, 1980.
US. Environmental Protection Agency, HealthEffects for Ethylbenzene, Final Draft,
ECAO-CIN-HO-08, Environmental Criteria and Assessment Office, Cincinnati,
Ohio, September, 1984.
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants, EPA/44Q-4-79-029a and b, Washington, D.C., December,
1979.
Verschueren, K., Handbook of Environmental Data on Organic Chemicals, Van
Nostrand Remhold Co., New York, New York, 1979, 659 p.
Weast, RE., ed.. Handbook of Chemistry and Physics, 62nded., CRC Press, Cleveland,
Ohio, 1981, 2332 p,
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OSWER Directive 9481 00-1
CHEMICAL AND PHYSICAL PROPERTIES OF
TOLUENE
Summary
CAS Number: 108-88-3
Chemical Formula: CgHsCh^
IDPACName: Methylbenzene
Important Synonyms and Trade Names: Toluol, phenylmethane, methylbenzene
Chemical and Phys|ca_l_grop_erties
Molecular Weight. 92.13
Boiling Point: 11Q.6°c
Melting Point: -953C
Specific Gravity: 0.8669 at 20°C
Solubility in Water: 534.8 mg/liter
Solubility in Organics: Soluble in acetone, Ngrotn, and carbon disulfide,
miscible with alcohol, ether, benzene, chloroform,
glacial acetic acid, and other organic solvents
Vapor Pressure: 28,7 mm Hg at 25°c
Vapor Density: 3.14
Viscosity: 0.625centipoise at 15.6°C
Flash Point: 4.4°C
Log Octanol/Water Partition Coefficient: 2.69
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OSWER Directive 948' 00-1
TrajQsgort_ajnd_Fate
Volatilization appears to be the major route of removal of trluene from
aquatic environments, and atmospheric reactions of toluene probably subordinate
alt other fate processes (EPA, 1979). Photooxidation is the primary atmospheric fate
process for toluene, and benzaldehyde is reported to be the principal organic
product Subsequent precipitation or dry deoosition can deposit toluene and its
oxidation products into aquatic and terrestrial systems. Direct photolyttc cleavage
of toluene is energetically improbable in the troposphere, and oxidation and
hydrolysis are probably not important as aquatic fates
The log octanol/water partition coefficient of toluene indicates that sorption
processes may be significant. However, no specific environmental sorption studies
are available, and the extent to which adsorption by sedimentary and suspended
organic material may interfere with volatilization is unknown. Bioaccumulation is
probably not an important environmental fate process. Although toluene is known
to be degraded by microorganisms and can be detoxified and excreted by mammals,
the available data do not allow estimation of the relative importance of
biodegradation/biotransforrnation processes. Almost all toluene discharged to the
environment by industry is in the form of atmospheric emissions.
Standards and Criteria
Rfd: 0.3 mg/kg/day
Ambient Water Quality Criteria (U.S. EPA}:
Aquatic Life
The available data are not adequate for establishing criteria. However, EPA
did report the lowest concentrations of toluene known to be toxic in aquatic
organisms, also known as the lowest effect level (LEL).
Freshwater
Acute toxicity: 17,500 ug/titer (LEL)
Chronictoxicity: No available data
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OSWER Directive 943? 00-it
Marine
Acute toxicity;
Chronic toxicity:
Human Health
Water and Fish Ingestion:
Fish ingestion Only:
6,300 ug/hter (LED
5,000 ug/ltter (LEL)
14.3 mg/liter
424,0 mg/liter
Others
NIOSH Recommended Standards:
OSHA Standards:
375 mg/m3 TWA
560mg/m3STEL
750 mg/m3 TWA
1,120 mg/m3 Ceiling Level
8-22
-------
QSWERDirective94ai QO-it
INTEGRATED RISK INFORMATION SYSTEM (IRIS) Chemical Files
Toluene, CAS No 108-88-3 (Revised 11/16/1986)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included m IRIS only after a
comprehensive review of chronic toxicity data by work groups composed or US EPA
scientists from several Agency Program Offices, The summaries presented m
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive US EPA
review. The risk management numbers (Section V) may not be hased on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers far
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Toluene
I. Chronic Systemic Toxicity: Noncarcinogenic Health Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: none
III, Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may riot exist for other toxic
effects such ascarcmogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound Please
8 23
-------
00-11
refer to the Background Document on the RfD (Appendix A) m Service Code 4 for an
elaboration of these concepts
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemtcal: Toluene
CAS No.: 108-88-3 Preparation Date 01/08/86
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF Mf RfD
Clinical chemistry
and hematologica!
parameters
300ppm(1130mg/cu. 100 1
m) converted to 29
mg/kg/day (NOAEL)
3E-1
mg/kg/day
Rat chronic inha- LOAEL: None
lation study
CIIT0980)
* Dose Conversion Factors & Assumptions: 5 days/7 days, 6 hour/24 hour;
0.5 absorption factor, 20 cu. rn human breathing rate; 70 kg, thus, 1130
rng/cu. m x 5 day/7 days x 6 hours/24 hours x 0,5 x 20 cu. m/day /7Q kg =
28.8 mg/kg/day
2 PRINCIPAL AND SUPPORTING STUDIES
CUT (Chemical Industry Institute of Toxicology). 1980. A 24-month inhalation
toxicology study in Fischer-344 rats exposed to atmospheric toluene. CUT, Research
Triangle Park, NC
Toluene is most likely a potential source of respiratory hazard. The only
chronic toxicity study on toluene was conducted for 24 months in male and female
F344 rats (CUT, 1980}. Toluene was administered by inhalation at 30, 100 or 300
ppm (113, 377 or 1130mg/cu. m)to 120 male and 120 female F344 rats for 6
hours/day, 5 days/week. The same number of animals (120 males and 120 females)
was used as a control Clinical chemistry, hematology and urinalysis testing was
conducted at 18 and 24 months. All parameters measured at the termination of the
study were normal except for a dose-related reduction in hematocrit values in
females exposed to 100 and 300 ppm toluene.
Based on these findings, a NOAEL of 300 ppm or 1130 mg/cu. m was derived.
An oral RfD of 20 mg/day can be derived using route-to-route extrapolation. This
was done by expanding the exposure from 6 hours/day, 5 days/week to continuous
8-24
-------
OSWER Directive 948? 00-''
exposure and multiplying by 20 cu m/day and 05 to reflect a 50% absorpuon
factor
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 100 An uncertainty factor of 100(10 for sensitive individuals and 10 for
mtraspecies extrapolation was also applied
MF = 1
4 ADDITIONAL COMMENTS
The only oral study found in the data base (Wolf et al , 1956) contains
subchronic data in which no adverse effects of toluene were reported at the highest
dose tested (590 rng/kg/day).
5. CONFIDENCE IN THE RfD
Study: High DataBase: Medium RfD: Medium
Confidence in the critical study is high because a large number of animals/sex
were tested in each of three dose groups and many parameters were studied.
Interim kills were performed. The data base is rated medium because several
studies support the chosen effect level. The confidence of the RfD is not higher than
medium because the critical study was by the inhalation route.
6. DOCUMENTATION AND REVIEW
Limited Peer Review and Agency-wide Internal Review, 1984.
U.S. EPA. 1985. Drinking Water Criteria Document for Toluene. Office of
Drinking Water, Washington, DC.
Agency RfD Work Group Review: 05/20/85, 08/05/85, 08/05/86
Verification Date: 05/20/85
B-25
-------
Directive 948' 00 1
7. U.S EPA CONTACTS
Primary. C T. DeRosa FTS/684 7534 or 513/569-7534
Office of Research and Development
Secondary ML. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Toluene
CAS No,: 108-88-3
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Toluene
CAS No.: 108-88-3
This chemical has not been evaluated by the U.S. EPA for evidence of human
carcinogenic potential
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
IV, RISK MANAGEMENT SUMMARIES
Chemical: Toluene
CAS No.: 108-88-3 Preparation Date: 09/30/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
B-26
-------
OSWEH Directive 9481 00-1»
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility Such considerations are indicated m
the table below {Considers Econ/Tech Feasibility) Please direct any questions you
may have concerning the use of risk assessment information m making a risk
management decision to the contact listed m Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E m Service Code 4.
RISK MANAGEMENT ACTIONS
Risk
Management
Action
Reportable
Quantity (RQ)
Status
Date
Final
1985
Risk
Management
Value
1000 Ibs
Considers
Econ/Tech
Feasibility
no
Reference
50 FR 13456
04/04/85
Water Quality
Criteria (WQC):
a. Human Health
b. Aquatic Tox'dty
1) Freshwater
2) Marine
Clean Air Act
Regulatory
Decision:
(NESHAPorNSPS)
Final
1980
Final
1980
Final
1980
Final
1984
14.3mg/l no
Acute no
17,50pug/I(LEL)
Chronic
none
Acute no
6,300 ug/l (LED
Chronic
5,000 ug/l (LEL)
Decision not no
to Regulate
45 FR 79318
11/28/80
ibid
ibid.
49 FR 22195
05/25/84
B. RISK MANAGEMENT RATIONALE
RQ
The final RQ is based on aquatic toxicity, as established under Section 311(b)(4)
of the Clean Water Act, ignitability and chronic toxicity. Available data indicate
that the aquatic 96-Hour Median Threshold Limit for Toluene is between 10 and 100
ppm. Its closed cap flash point is less than 100 degrees F and its boiling point is
greater than 100 degrees F. RQ assignments based on chronic toxicity reflect two
primary attributes of the hazardous substance, the minimum effective dose (MED)
levels for chronic exposure {mg/day for 70-kg man) and the type of effect (liver
necrosis, teratogenicity, etc). In accordance with the methodology described in the
Agency's "Techmcal Background Document to Support Rulemaking Pursuant to
8-27
-------
OS'A'ER Directive 9481 00-1 '
CERCLA Section 102. Volume 1" of March 1985 and 50 FR 13468 (04 04/85), a
composite score is determined from an evaluation of these two attributes Toluene
was determined to have a composite score between 6 and 20, corresponding to a
chronic toxicity RQ of 1000 pounds.
Contact: RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
WQC
Contact: Office of Water Regulations and Standards
202-382-5400 or FTS-382-5400
a. Human health: The WQC of 14 3 mg/l is based on consumption of
contaminated aquatic organisms and water A WQC of 424 mg/l has also been
established based on consumption of contaminated aquatic organisms alone
b. Aquatic toxicity Water quality criteria for the protection of aquatic life are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The "{LED" after the value indicates that the minimum data were not
available and the concentration given is not a criteria value but the lowest effect
level found in the litetature
CAA Regulatory Decision
EPA concluded that current information does not indicate that toluene
endangers public health at ambient concentrations {excluding emergency releases),
and thus no regulation directed specifically at toluene is necessary at this time
under the CAA
Contact: Chief, Pollutant Assessment Branch
FTS/629-5645 or 919/541-5645
V. SUPPLEMENTARY DATA
Chemical: Toluene
CAS No,: 108-88-3
Information is not available at this time.
Synonyms: ANTISALIa, METHYL-BENZENE, METHACiDE, PHENYL-METHANE,
METHYLBENZENE, METHYLBENZOL, NCI-C07272, PHENYLMETHANE, RCRA WASTE
NUMBER U220, TOLUEEN (Dutch), TOLUEN {Czech), TOLUENE , TOLUOL TOLUOLO
(Italian). TOLU-SOL, UN 1294
B 28
-------
OSWER D"-eetive 948" 00-'
EPA (U.S. Environmental Protection Agency), 1979 Water:_Related E n vi ronmental
Fate of 12_9__Pr|ority Pollutants, EPA/440-4-79-029a and b, Washington, D C ,
December
Other Resource Documents
American Conference of Governmental Industrial Hygienists, Documentation
of the Threshold Limit Values, 4tn ed , Cincinnati, Ohio, 488 pp , 1980
McCoy and Associates, "Physical/Chemical Data Compendium for Common
Solvents," The Hazardous Waste Consultant, Vol 4, No. 6, Nov. /Dec., 1986, pp
4-1 to 4-32
National Institute for Occupational Safety and Health, Criteria for a Recommended
Standard-Occupational Exposure to Toluene, DHEW Publication No (NiOSH)
HSM 73-1 1023, Washington, D.C, 1983.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base, Washington, DC , October, 1983.
National Research Council, The Alky! Benzenes, National Academy Press,
Washington, D.C., 1980.
Sax, N. I., Dangerous Properties of Industrial Materials, 4th ed.. Van Nostrand
RemholdCo.,NewYork, 1975,1,258pp.
U.S. Environmental Protection Agency Ambient Water Quality Quality Criteria
for Toluene, EPA/440-5-80-075, Office of Water Regulations and Standards,
Criteria and Sf3ndards Division, Washington, D.C., October, 1980.
U.S. Environmental Protection Agency, Health Effects Assessment for Toluene, Final
Draft, ECAO-CIN-HO-03, Environmental Criteria and Assessment Office,
Cincinnati, Ohio, September, 1984.
B-29
-------
Directive 94gt 00-i'
Weast, R^ E,,ed., Handbook of Chemistry and Physicy62pd ed. CRC Press.Cleveiand,
Ohio, 1981, 2,332 pp
B-30
-------
OSWER Directive 9481 00-11
APPENDIX C
RESULTS OF STATISTICAL TESTS
C-1
-------
K8"
TEST OF PROPORTIONS
If greater than 75 percent of the data are below the detection 'irrm /aues, a^d
the detection limit is consistent throughout the data set (upgraa«ent and
downgradient), the test of proportions may be used The procedure is to calculate
the proportion of below detection limit values upgradient and the proportion of
below detection limit values downgradient, then use a omormal test wth a normal
approxtmat'on to compare the proportions This orocedure is described :n more
detail below:
Let Pu = the proportion of weMs with non-detects upgradient.
Let Pd = the proportion of wells with non-detects downgradient
Test versus
HQ. PU = Pd Ha; Pu > PI-J
From a set of data calculate
(# of upgradient non-detects) - x
(total # of upgradient observations) = n
(# of downgradient non-detects) = y
{total # of downgradient observations) = m
Reject H0: if
* JL
n - m
i X -t- V 1 ,
• — £. (n +
*
>Za
\
m)
'
nm
where 2a can be found m a table of the standard normal distribution (found in
most statistics t°xt books). For a confidence level of 0-05, Z is 1.645.
C-2
-------
OSWER Directive 9481 00-11
2
UJ
M
_l CD
=>O
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|S
?ae
==£
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3
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W
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nt
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CO
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ample Test
m
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m
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valuel (2 tailed t-
distribution)
C-3
-------
OSWER Directive 9481 00-11
MANN-WHITNEY TEST RESULTS
RIVER WATER SAMPLES-o-DICHLOROBENZENE'
Statistical Parameters
Exact Test
Sum of Ranks
Mann-Whitney Statistic, u
Critical Value, W
nm - W
Approximate Large Sample Test
Mean of U
Std Deviation of U
(Z-valuel
Prob(IZl) >l2-valuel
(2-tailed t-distribution)
Paired Sampling Stations
SW-1,SW-2
188.5
97.5
46
128
84.5
19.5
0.6667
0.5050
SW-1.SW-5
156
65
46
128
84.5
19.5
1
0.3173
SW-2.SW-5
166
75
46
128
84.5
19.5
0.4872
0.6261
Run only where o-dkhtorobenzene detected at at least one of tho two
stations; and concentrations greater at the downgradient station.
C-4
-------
O5WER Directive 948? 00-11
MANN-WHITNEY TEST RESULTS
RIVER WATER SAMPLES - ETHYLBENZENE
Paired Sampling Stations
Statistical parameters
ixactTest
Sum of Ranks
Mann-Whitney Statistic.
U
Critical Value, W
nm-W
Approximate Large Sample
Test
Mean of U
Std Deviation of U
IZ-value I
Prob IZ-va!uel
{2-tailed t-drstrtbution)
SW-1,
SW-2
1885
97 5
46
128
845
19.5
06667
0.5050
SW-1,
SW-5
1495
58 5
46
128
84.5
19.5
1 3333
0.1824
SW-2,
SW-5
1665
755
46
128
845
19.5
0.4615
0.6444
SW-3.
SW-5
149 5
58.5
46
128
84,5
19.5
1 3333
0.1824
SW-4,
SW-5
'495
58 5
46
128
845
195
1 3333
0.1824
C 5
-------
OSWER Directive 9481 00-11
STEEL'S MANY-ONE RANK TEST*
RIVER WATER SAMPLES
Constituent
Ohlorobenzene
o-Dichlorobenzene
Ethylbenzene
Sum of Ranks
SW-2
1900
188.5
188.5
SW-3
212.0
175.5
175,5
SW-4
187 5
175,5
175.5
SW-5
1980
1950
1950
Critical
Value**
2190
219.0
2190
RIVER SEDIMENT SAMPLES
Constituent
Chlorobenzene
Sum of Ranks
SW-2
175.5
SW-3
201.5
SW-4
201,5
SW-5
195.0
Critical
Value**
219.0
Result is statistically significant if the sum of the ranks is greater than or
equal to the critical value.
Calculated using alpha = 0.05, four downstream stations; 13 samples.
C-6
-------
OSWER Directive 9481 00-11
ACL
CASE STUDY 5
-------
OSWER Directive 9481.00-1
CONTENTS
SECTION RAGE
1.0 EXECUTIVE SUMMARY 1-1
2.0 INTRODUCTION / 2-1
2.1 FACILITY DESCRIPTION 2-1
2.2 APPROACH TO ACL DETERMINATION 2-2
2.3 REPORT ORGANIZATION 2-5
3.0 IDENTIFICATION OF ACL CONSTITUENTS 3-1
3.1 HAZARDOUS CONSTITUENTS IN THE WASTE 3-1
3.2 EXTENT AND DEGREE OF CONTAMINATION 3-1
4.0 GENERAL INFORMATION 4-1
4.1 LAND USE 4-1
4.2 WATER USE AND USERS 4-1
4.3 PRECIPITATION AND EVAPOTRANSPIRATION 4-4
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION 5-1
5.1 REGIONAL GEOLOGY 5-1
5.2 SITE GEOLOGY 5-2
5.3 GROUND-WATER HYDROLOGY 5-2
6.0 EXPOSURE PATHWAYS. 6-1
6.1 POTENTIAL HUMAN EXPOSURE 6-1
6.2 POTENTIAL ENVIRONMENTAL EXPOSURE 6-1
6.3 REFERENCE EXPOSURE LEVELS 6-1
7.0 CONTAMINANT TRANSPORT ANALYSIS 7-1
7.1 RELATIVE FLOW VELOCITIES OF CONSTITUENTS 7-1
7.2 DISPERSIVITY 7-3
7.3 DISPERSION COEFFICIENT 7-4
7.4 MODELED CONCENTRATIONS 7-5
8.0 DEVELOPMENT OF ACLs 8-1
HI
-------
OSWER Directive 9481.00-11
CONTENTS (continued)
SECTION PAGE
9.0 GROUND-WATER MONITORING AND SOURCE REDUCTION 9-1
MEASURES
9.1 GROUND-WATER MONITORING 9-1
9.2 SOURCE REDUCTION MEASURES 9-1
REFERENCES R-1
APPENDICES
LOCATION OF INFORMATION IN THE CASE STUDY A-1
SUPPORTING THE 19 REGULATORY CRITERIA UNDER
§264.94(b)(1) AND §264.94(b)(2)
B CHEMICAL AND PHYSICAL PROPERTIES AND IRIS B-1
(INTEGRATED RISK INFORMATION SYSTEM) DATA BASE
FOR MERCURY, METHYLENE CHLORIDE, TOLUENE, 1,1,2-
TRICHLOROETHANE, AND TRICHLOROETHYLENE
IV
-------
OSWER Directive 9481.00-11
TABLES
NUMBER PAGE
3-1 Appendix IX Constituents in Waste Streams 3-2
3-2 Maximum Concentrations of Hazardous Constituents 3-4
Observed During 1984-1986
5-1 Ground-Water Elevations (1987) 5-5
5-2 Summary of Average Properties of the Uppermost Aquifer 5-7
5-3 Aquifer Test Results 5-9
6-1 Reference Human Health Exposure Levels 6-3
7-1 Parameters for Relative Flow Velocity 7-3
7-2 Calculated Concentrations 7-6
8-1 Proposed Alternate Concentration Limits 8-2
-------
OSWER Directive 9481.00-11
FIGURES
NUMBER ' PAGE
2-1 Site Layout, Topography and Monitoring Well Locations 2-3
2-2 Monitoring Wells in the Vicinity of Facility F 2-4
3-1 Isopleths for Mercury 3-6
3-2 Isopleths for Toluene 3-7
3-3 Isopleths for 1,1,2-Trichloroethane 3-8
3-4 Isopleths for Trichloroethylene 3-9
4-1 Location of Facility F Adjacent to Playa in Tectonic Basin 4-2
4-2 Regional Locator Map 4-3.
4-3 Precipitation and Evapotranspiration at Facility F 4-5
5-1 Locations of Monitoring Wells, Soil Borings, and Geologic 5-3
Cross Section A-A'
5-2 Geologic Cross Section A-A' 5-4
5-3 Water Table Contours 5-6
VI
-------
OSWER Directive 9481 00-11
1.0 EXECUTIVE SUMMARY
Case Study 5 is a hypothetical example of an alternate concentration limit
(ACL) application. This hypothetical application illustrates Case 5 of Part I of the
ACL Guidance Document (EPA, 1987a), which applies to land disposal units over
non-potable aquifers. For such units, the Point of Exposure (POE) is determined on a
case-by-case basis, and the ACL must be established so as to pose no unacceptable
risk to public health and the environment.
The site is located above a saline aquifer (total dissolved solids > 20,000 ppm)
in an arid region of the western United States. Contamination has been found in
ground water extending beyond the facility boundary. There are two small
communities within ten miles of the site, both having total populations under 300.
There are no residents downgradient of the site, and land immediately surrounding
the site is not suitable for agriculture or domestic use.
Ground-water transport at this site is moderately slow through silty, fine to
medium-grained sand. The evapotranspiration rate exceeds the average
precipitation rate. Ground water in the uppermost aquifer is unsuitable for
drinking and is used by some residents in the area for heat pumps. Industrial uses
are limited to cooling water. There are no surface waters within ten miles of the
site.
Hazardous constituents detected in ground water at the site are mercury,
methylene chloride, toluene, 1,1,2- trichloroethane, and trichloroethylene. Of
these, all but methylene chloride occur in plumes that extend beyond the property
boundary. Exposure pathways for each of the contaminants are discussed in this
application. Fate and transport arguments are applied to the ground-water
contamination, and attenuation by dispersion was considered using a contaminant
transport model. Acceptable drinking water levels are developed as reference
levels. The proposed ACLs rely on fate and transport considerations and are based
on the current levels in the Point of Compliance (POC) wells.
1-1
-------
OSWER Directive 9481 00-:
2.0 INTRODUCTION
This document is a hypothetical example of an application by Facility F for
alternate concentration limits (ACls) [40 CFR 264.94(b)] for the hazardous
constituents that have been detected in the ground water at locations within and
beyond the property boundary of the facility. This application was developed as an
example of Case 5 of the ACL Guidance Document (EPA, 1987a) for units over non-
potable aquifers. For such units, the Point of Exposure (POE) is determined on a
case-by-case basis, and the ACL must be established so as to pose no unacceptable
risk to human health and the environment. The non-potable aquifer must also be
isolated from any potable aquifer.
Mercury, methylene chloride, toluene, 1,1,2-trichloroethane (TCA), and
trichloroethylene (TCE) are the hazardous constituents for which the ACL
demonstration is being made. Advection/dispersion and adsorption are the major
mechanisms chosen to determine the degree of attenuation of contaminant
concentrations.
2.1 Facility Description
Facility F is a 488-acre chemical manufacturing facility that contains onsite
hazardous waste land treatment, storage, and disposal units. The facility, which has
been in operation since 1930, manufactures chemicals in its manufacturing units in
the northeastern portion of the property. The waste management units are as
follows:
Approximate
Unit Acreage Status
Wastewater/bioequalization ponds 20 operating
Land treatment area 18 operating
Sludge landfill 16 closed
Sludge storage pond 13 operating
Past disposal unit 16 closed
Landfill disposal area 12 operating
2-1
-------
OSWERDireai ve 9481 00-M
The site topography, boundaries, monitoring wells, buildings, and waste
treatment/disposal units are shown in Figure 2-1. Monitoring wells in the vicinity of
the site are shown in Figure 2-2.
This demonstration addressess releases of hazardous constituents to the
uppermost aquifer from three waste management units. Methylene chloride, TCA
and TCE have been released frorp'the past disposal unit and landfill disposal cell 1
(Figure 2-1). Toluene has also been released from landfill disposal cell 1. Mercury
has been released from the wastewater treatment pond in the northeastern portion
of the site.
The past disposal unit (in the south-central portion of the facility) began
accepting wastes in the early 1930's. In 1953, an area in the southeast corner of the
site was developed for future landfill disposal. This landfill disposal area presently
contains one landfill cell. Both disposal units include a compacted clay liner, a gas
ventilation system, and a dike system for runon/runoff control. The clay liners
beneath the landfill units are approximately 10 fest above the water table. The
dike systems protecting the landfills are designed to retain runoff from the
24-hour 100-year storm. Water drains to the southeast corner of each landfill where
it is collected and treated as contaminated water. Since 1984, wastes to be
landfilled must pass the "free liquid test" before landfilling. Landfilling of waste is
accomplished by spreading and compacting the waste via the progressive slope or
ramp methods.
Land treatment is done at one 17-acre unit. Various organic wastes from the
wastewater treatment pond are treated in this unit. This landfarm was constructed
by removing the topsoil and building 2-foot-high dikes to retain runoh and prevent
runoff from the 24-hour 25-year storm. The soils beneath the land treatment
facility have a moderate permeability (silty sands with trace amounts of clay; see
Section 5.2).
2.2 Approach to ACL Determination
Part I of the ACL Guidance Document (EPA, 1987a) establishes five cases for
reviewing ACL demonstrations. Facility F meets the conditions of Case 5 because it
2-2
-------
\ \ \ \ a
MW-27Q
DMW-19 / CW9»
CW-10«
MW-20H CW-12«
LEGEND
• Compliance Well
O Monitoring Well
Facility Boundary
^ Contour Elevation,
°NFeet(MSU
^O
^.Concentration, mg/l
0 500 1000
—^B5^5
Scale. Feet
FIGURE 2-1. SITE LAYOUT. TOPOGRAPHY AND MONITORING WELL LOCATIONS
-------
OSWER Directive 9481.00-11
LEGEND
• Monitoring Wall
® Nested Monitoring Well
Contour Elevation, Feet (MSL)
FIGURE 2-2. MONITORING WELLS IN THE VICINITY OF FACILITY F
2-4
-------
OSWER Directive 9481.00-n
is located over an aquifer with total dissolved solids (IDS) in excess of 20,000 ppm
(see Section 5.3; such ground water is considered non-potable) and because it is
isolated from the deeper aquifer by 370 feet of relatively impermeable bedrock.
ACL demonstrations for sites that meet the conditions of Case 5 are assessed on a
case-by-case basis.
Potential pathways of ecosystem exposure and human exposure to drinking
water were evaluated. Because the aquifer is very saline and not hydraulically
connected to any other potable ground-water source, the potential for direct
human exposure pathways is low. According to the criteria outlined in the EPA
Ground Water Protection Strategy (EPA, 1984), the unconfined aquifer qualifies as
Class III ground water. Ecosystem exposure is low because the water does not
discharge to the surface.
Human health exposure levels for the hazardous constituents are developed
even though no human exposure could occur. These reference levels are based on
drinking water maximum contaminant levels (MCLs) and on models of systemic
toxicity and carcinogenicity for ingestion of contaminated water. Analytical
modeling shows that, near the boundary of Facility F, concentrations are near the
human health levels. On this basis, the proposed ACLs have been established at the
present levels of contamination at the compliance monitoring wells.
2.3 Report Organization
This application is presented in nine sections: executive summary,
introduction, identification of ACL constituents, general information, geologic and
hydrologic information, exposure pathways, contaminant transport analysis,
development of ACLs, and ground-water monitoring and source reduction
measures. The ACL factors listed in 40 CFR 264.94(b) are discussed within these nine
sections. Appendix A shows the correspondence between the regulatory
requirements and the location of material within this application. Appendix B
provides the chemical and physical properties of the ground-water constituents that
have exceeded background values.
2-5
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OSWER Directive 9481 00-11
The discussion in these sections presumes a familiarity with Part I of EPA's ACL
Guidance Document (EPA, 1987a). The discussion also assumes a familiarity with
information provided in the Part B permit application for this facility. Data that
would appear in that document are not reproduced in this case study except where
they were deemed necessary for the sake of clarity and continuity. Specific sections
of the Part B permit application are'referenced throughout this application.
2-6
-------
05W E R Di recti ve 9481.00-11
3.0 IDENTIFICATION OF ACL CONSTITUENTS
This section identifies the hazardous constituents thought to be present in the
waste generated at Facility F. In addition, this section describes the extent and
degree of contamination measured in the ground water underlying the facility.
3.1 Hazardous Constituents in the Waste
Section C of the Part B permit application contains the results of the
comprehensive chemical and physical waste characterization program. The list of
Appendix IX constituents found in the waste streams at Facility F is presented in
Table 3-1.
3.2 Extent and Degree of Contamination
Ground-water monitoring at detection wells screened in the uppermost
aquifer beneath Facility F has detected increased concentrations of five Appendix IX
constituents downgradient of the hazardous waste units. These constituents are
mercury, methylene chloride, toluene, TCA and TCE. Appendix B describes the
pertinent physical, chemical, and biological properties of these constituents.
Detection monitoring at this facility was performed quarterly between the
spring of 1983 and the summer of 1984. In the summer of 1984, samples from both
the uppermost, unconfined and the deeper, confined aquifers were analyzed for
Appendix VIM constituents as required by regulations current at that time; the five
constituents named above were detected in elevated concentrations in the
uppermost unit. No Appendix VIM constituents were detected in elevated
concentrations in the bedrock aquifer. Following this initial sampling, a complete
characterization of the extent of ground-water contamination was performed and
a compliance monitoring program was developed as required in 40 CFR 264.99.
The monitoring wells are shown in Figures 2-1 and 2-2. There are five
background wells [MW-1,. MW-2, MW-3 and N-1 (which counts for two)] and 45
downgradient wells. The downgradient wells include wells MW-4 through MW-33,
3-1
-------
OSWER Directive 9481.00-11
TABLE 3-1.
APPENDIX IX CONSTITUENTS IN WASTE STREAMS
Category
Volatile
Aromatic
Hydrocarbons
Chlorinated
Volatile
Organics
Ketones
Acid
Extractable
Organics
Base/Neutral
Extractable
Organics
Others
Compound
Benzene
Toluene
Ethylbenzene
Xylenes
Chlorobenzene
1,2-Dichloroethane
1,1,1-Trichloroethane -
1,1-Dichloroethane
1,1,2-Trichloroethane (TCA)
1 , 1 ,2,2-Tetrachloroethane
Chloroethane
Chloroform
1 , 1 -Dichloroethylene
Trans-1 ,2-dichloroethylene
Methylene chloride
Fluorotrichloromethane
Tetrachloroethylene
Trichloroethylene (TCE)
Carbon tetrachloride
Acetone
Methyl ethylketone
Methyl isobutyl ketone
Phenol
2-Nitrophenol
2,4-Dimethyl phenol
Bis (2-Chloroethyl) ether
1 ,2-Dichlorobenzene
Nitrobenzene
Isophorone
Napthalene
Bis (2-Ethylhexyl) phthalate
Mercury
3-2
-------
OSWER Directive 9481.00-11
compliance wells CW-1 through CW-13, and nested wells N-1 and N-2. Three wells
(MW-19, MW-25, and MW-26) are screened in the lower, bedrock aquifer The
remaining wells are screened within the upper, alluvial fan sediments.
Table 3-2, prepared from data in Section F of the Part B permit application,
presents the maximum concentrations observed at selected wells and sample points
for the five detected constituents.-The highest mercury concentration is in Well CW-
1; adjacent to the wastewater treatment pond in the northeast portion of the
facility. The highest toluene concentration is in Well CW-7, adjacent to the
currently operating landfill disposal cell 1. The highest methylene chloride, TCA and
TCE concentrations are in Wells CW-6, CW-11 and CW-10, respectively, adjacent to
the past disposal unit.
Isopleths for mercury, toluene, TCA and TCE are presented in Figures 3-1
through 3-4. Methylene chloride concentrations are too low and the data points
too few to permit construction of an isopleth. The data indicate three contaminant
sources, each with somewhat different leachate characteristics. Concentrations in
wells west of MW-22 and MW-31 are contributions from both the landfill disposal
cell 1 and the past disposal unit.
3-3
-------
TABLE 3-2.
MAXIMUM CONCENTRATIONS OF HAZARDOUS CONSTITUENTS
OBSERVED DURING 1984-1986
Well
MW-1
MW-2
MW-3
MW-4
MW-5
MW-6
MW-7
MW-8
MW-9
MW-10
MW-11
MW-1 2
MW-1 3
MW-1 4
MW-1 5
MW-1 6
MW-1 7
MW-1 8
MW-1 9
MW-20
MW-21
MW-22
MW-23
MW-24
MW-2 5
MW-26
MW-27
MW-28
Mercury
(mg/l)
<0.001*
<0.001
<0.001
0.006
<0.001
<0.001
<0.001
<0.001
<0.001
< 0.001
<0.001
<0.001
<0.001
<0.001
<0.001
0.009
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
0.005
<0.001
<0.001
Methylene
Chloride
(mg/iy
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
< 0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
Toluene
(mg/l)
0.220
<0.005
<0.005
<0.005
<0.005
<0.005
0.065
<0.005
0.025
<0.005
<0.005
<0.005
<0.005
0.240
< 0.005
<0.005
0.039
0.130
0.285
0.270
0.125
0.390
0.085
<0.005
<0.005
<0.005
0.320
0.210
TCA
(mg/l)
<0.001
<0.001
< 0.001
<0.001
<0.001
<0.001
0.005
<0.001
<0.001
<0.001
< 0.001
<0.001
<0.001
0.012
<0.001
<0.001
0.006
0.008
0.018
0.017
0.008
<0.001
0.003
<0.001
<0.001
<0.001
0.019
0.002
TCE
(mg/l)
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
0.031 -
<0.001
<0.001
<0.001
<0.001
< 0.001
<0.001
0.048
<0.001
<0.001
0.029
0.036
0.073
0.054
0.016
0.025
0.026
<0.001
<0.001
<0.001
0.110
0.031
3-4
-------
TABLE 3-2. (continued)
MAXIMUM CONCENTRATIONS OF HAZARDOUS CONSTITUENTS
OBSERVED DURING 1984-1986
Well
MW-29
MW-30
MW-31
MW-32
MW-33
CW-1
CW-2
CW-3
CW-4
CW-5
CW-6
CW-7
CW-8
CW-9
CW-10
CW-11
CW-1 2
CW-1 3
Mercury
(mg/l)
0.020
0.005
0.001
<0.001
<0.001
0.036
0.023
0.011
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
Methylene
Chloride
(mg/l);
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
0.009
0.004
<0.001
<0.001
0.007
0.003
<0.001
<0.001
Toluene
(mg/l)
<0.005
<0.005
0.435
<0.005
<0.005
<0.005
<0.005
<0.005
0.395
1.430
1.100
1.850
0.950
0.400
0.370
0.390
0.405
0.330
TCA
(mg/l)
<0.001
<0.001
0.006
<0.001
<0.001
<0.001
<0.001
<0.001
0.009
0.011
0.026
0.013
0.005
L 0.010
0.030
0.046
0.025
0.009
TCE
(mg/l)
<0.001
<0.001
0.067
<0.001
<0.001
<0.001
<0.001
<0.001
0.037
0.045
0.150
0.130
0.047
0.126
0.170
0.150
0.115
0.062
' < " means below the indicated detection limit.
3-5
-------
OSWER Directive 9481 00-11
\ \ \
o m ID Q
LEGEND
• Compliance Well
O Monitoring Well
Facility Boundary
"6 Contour Elevation,
\Faet (MSU
""*«
'"^Concentration, mg/l
0 500 1000
1
Scale, Feet
-N-
I
FIGURE 3-1. ISOPLETHS FOR MERCURY
-------
• 0.400 Q 0.370 V* 00396
0-.270Q 0.406*
0.125 V 0.330)1
LEGEND
• Compliance Well
O Monitoring Well
Facility Boundary
"6 Contour Elevation.
\Feet(MSU
^O
'•^Concentration, mg/1
0 BOO 1000
^messf
Scale, Feet
FIGURE 3-2. ISOPLETHS FOR TOLUENE
-------
OSWER Directive 9481 00-11
LEGEND
• Compliance Wall
O Monitoring Well
Facility Boundary
"4 Contour Elevation,
\Feet(MSL)
-<>
•^Concentration, mg/l
0 500 1000
^iS^SSS
Scale, Feet
I
-N-
*
FIGURE 3-3. ISOPLETHS FOR 1,1.2-TRICHLOROETHANE
-------
LEGEND
• Compliance Well
H Monitoring Well
Facility Boundary
~~£ Contour Elevation,
\Feet
-------
OSWER Directive 9481 00-11
4.0 GENERAL INFORMATION
This section provides a brief description of the regional characteristics relevant
to this application. A complete description is provided in Section B of the Part B
permit application. Land use, water use, and precipitation/evapotranspiration are
described below. /
4.1 Land Use
Facility F is located on a 488-acre site within a 5,000-square-mile topographic
and tectonic basin in the western United States. A playa comprises most of the
basin area (Figure 4-1). Situated some 50 miles west of the nearest standard
metropolitan statistical area, Facility F is surrounded by lands belonging to the state
in which the site is located. The state lands are classified for multiple use but are not
currently used for commercial, residential, or agricultural purposes. No plans have
been made for future use, and none are anticipated.
As shown in Figure 4-2, the nearest town, Community B, is 9 miles southwest of
the facility and has a population of 250 people. No settlements are located west
(hydrogeologically downgradient) of the facility. The area surrounding Facility F is
not suitable for commercial use in ways other than that for which the facility is
using the land, nor is the land suitable for agriculture or domestic use. Communities
A and B serve as truck stops along an interstate highway.
The area surrounding the facility contains very little vegetation and provides
little habitat for most animals. The Fish and Wildlife Service has stated that no
threatened or endangered species have been observed in the general area of
Facility F (see Appendix 5 of the Part B permit application).
4.2 Water Use and Users
Ground water from the uppermost aquifer in the 5,000-square-mile basin is
used by 12 industrial facilities and less than 100 non-drinking domestic water users.
The industrial uses are limited to cooling water. The domestic uses are principally
4-1
-------
OSWER Directive 9481 00-11
lnt«r>ut» Highway ,*• .*. - ^
* :*--i* ."PLAYA
-*•*.'**-.. * ~"' *-
-•
TECTONIC BASIN BOUNDARY "
.-«-- TECTONIC BASIN BOUNDARY
Ground-Water Plow
Direction
Scale, Miles
FIGURE 4-1. LOCATION OF FACILITY F ADJACENT TO PLAYA
IN TECTONIC BASIN
4-2
-------
LEGEND
Elevation, 1000-Foot Interval (MSU
FIGURE 4-2. REGIONAL LOCATOR MAP
m
<
a
o
o
-------
OSWER Directive 9481 00-! I
for heat pumps. There are no injection or withdrawal wells on site and no surface
waters within ten miles of the site. No drinking water uses of the uppermost
aquifer are expected in the basin at any time in the future because the salinity
throughout the basin exceeds 20,000 mg/l IDS (refer to Section D of the Part B
permit application for offsite monitoring data). Federal and State drinking water
standards recommend 500 mg/l as the maximum IDS.
Water for drinking, agricultural use, and manufacturing operations is
obtained from supply wells that draw from the deeper, confined (bedrock) aquifer
at a depth of 450 feet. The nearest supply wells are approximately three miles east
of the facility. A 350-foot-thick aquitard separates the upper, unconfined and
deeper, confined aquifers.
Ground-water allocation in the State is governed under the doctrine of prior
appropriation. Permits must be obtained from the State engineer for all ground-
water withdrawals. Under this authority, the State will not permit wells drawing
from the uppermost aquifer for use as drinking water. This policy is corroborated
by documents provided in Appendix 4 of the Part B permit application.
4.3 Precipitation and Evapotranspiration
Facility F is located in the arid western region of the United States. Average
monthly precipitation at Facility F between 1983 and 1986 is presented in Figure 4-3.
As shown in this figure, evapotranspiration is high and often exceeds precipitation.
Soil moisture recharge typically occurs November through February.
4-4
-------
2.0".
1.5"
1.0" -
0.5"
r
j
i i
F
LEGEND
X
Illllllllll
M
-X
II
III 1 III 1 1
A M J J ASON
PrAf* initat iftn
r i cui|ji Kaiiui i
Actual Evapotranspiration
Soil Moisture Utilization
I I
D
Soil Moisture Recharge
FIGURE 4-3. PRECIPITATION AND EVAPORATION AT FACILITY F
-------
OSWER Directive 9481 00-11
5.0 GEOLOGIC AND HYDROLOGIC INFORMATION
Facility F is in the Basin and Range province in the western United States. The
site is on an alluvial fan at the edge of a playa. This section describes the geology
and hydrology of the facility area. More detail is provided in Section D of the Part B
permit application.
5.1 Regional Geology
Block faulting is the probable mechanism responsible for the landforms in the
Basin and Range province. Generally, two stages of tectonism are thought to have
created the structures and topography. Compressive forces in the Cretaceous
produced folding and thrust faulting, which was likely followed by east-west tensile
stresses producing high-angle normal faults along the block margins. Lowland
plains were created on the down-dropped fault blocks. Clastic material, eroded
from the new mountain ranges created on either side, was deposited in alluvial
plains.
Bedrock exposures several miles east, south, southwest and north of the site
are Permian sandstones, limestones, and dolomites. Two miles east of the site,
basalt and andesite of Pliocene/Miocene age are exposed. Two small northeast
trending anticlines are exposed in the Permian rocks north of the site. The folded
structures are thought to be related to early compressive forces, while the basalts
may be temporally associated with the tension stresses that caused Basin and Range
faulting.
The site is on an alluvial fan at the edge of an arid basin that was originally
occupied by a Pleistocene lake, now a playa. The location of the site within this
basin is shown in Figure 4-1. The near-surface deposits beneath the eastern part of
the basin (west of the facility) are fine to medium-grained alluvial deposits
(interbedded silty sands and fine to medium sands), as evidenced in borings MW-32,
MW-33, and MW-7 (Section D of the Part B permit application).
5-1
-------
OSWER Directive 9481.00-11
5.2 Site Geology
Subsurface conditions on site have been characterized by two field
investigations. These studies, conducted in the summers of 1981 and 1984, included
50 sort borings and the installation of 45 monitoring wells, 8 of which are pairs of
nested wells (Figure 5-1). Field and laboratory analyses were also performed on site
soils (Section D of the Part B permit application). A cross section of the soils beneath
the site is shown in Figure 5-2. The location of this cross section is shown in Figure
5-1.
The top five feet of unconsolidated sediment consist of a brown, dry to moist,
medium dense, silty sand and some clay with anhydrite minerals. This material was
encountered in all borings. The uppermost layer grades into a light gray, moist to
wet, medium-dense fine sand. This second unit extends from approximately five
feet below grade to 15 to 20 feet below grade. Below this depth is a third unit^a
gray, wet, medium to dense, fine to medium sand and silty sand. Minor
discontinuous silt lenses were encountered in some borings. The third unit extends
laterally westward as evidenced by borings for wells MW-7,13, MW-33, and MW-32.
Based on ground-water elevations measured in site wells, this third unit is the
uppermost aquifer.
Bedrock was encountered approximately 100 feet below site grade on the east
side of the site. Borings on the west side of the site extended 120 feet below site
grade and encountered predominantly silty sands and fine to medium sands. The
bedrock encountered in the borings on the east side of the site is thought to be the
source of the topographic high which exists in this area. The bedrock encountered
consists of a cherty limestone with some interbedded siltstone. Cherty limestones
are exposed in folded structures along the structural strike of the limestones two
miles east of the facility.
5.3 Ground-Water Hydrology
Water table elevation data have been collected quarterly over the 1981-1984
period at onsite and offsite monitoring wells. Nested monitoring wells were
5-2
-------
LEGEND
• Compliance Well
D Monitoring Well
O Soil Boring
Contour Elevation,
Feet (MSL)
Facility Boundary
I
0 500 1000
i^SE?™—!
Scale, Feet
FIGURE 5-1. LOCATIONS OF MONITORING WELLS, SOIL BORINGS,
AND GEOLOGIC CROSS SECTION A-A*
-------
OSWER Directive 9481.00-11
Facility Boundary
•- v-; '•-..••"; •' :•-..•-.•..•-•:.: ;*•••-..• '•'.-...-.-.•••*•.: -••:•-...•».••<>.'-•• •'.•.„. --.-o.'..;-.«.••.•',>.••:'.' •„.'••' -
. ••". • .< 0-> «.•••••..-••»••• •«.'..-;• •• ° •.-«.•«•». ..••••.!••.«».• v ,°•
^•^-v? :^^;:p-:^S^^v;^-;;v^:^ ^i^^i;^:^ ^ #
••• '.6'. '.-. •?•••'•:.•:?."•'».'•.•''.•-•.••••-i ••'.--.•••..•«;;<'•••.'-«:• «.••.;•*: •:.«.. .-«-f.o..-i.-.,.-•• .•«;. •
;.v°.---;.?.:.r :-.:^o.:^.v:-:a:^:/v.i.^Vv•0•:":v.^.v;:^:.^v;^•.ri•;.v^>-:.v;:^^;^••;'•
• •<;•••.•;" >-.••:-.°.--.v. •••.-/.••?.•••;.••.-.•„:•.: :..•-••.V..:°.,-..-•.•/-• .»••:•-..•.•:--..•.-•.•.••.• v-v---;--'-°;-.-D
•'.••.°••".•••• V* ••-:•'-••;••••••.••;,•:••'." ••«.°v ".-....- .--..-•••*.-•••.• i-'.^Vo'-i --i-.'." •'•.•";"••
•o' ••'•.». '••••".• /•o. -•...•". O •• .-0. , • O. • C. ,. ..o • .. o- ' O • . . • • .0• . ' .« •* •"•*. ' ' ..*-•• ,'b' •• .0
°-.- •••;-..-•• v.v-•>.-.-.•;•..,--.•.•• .;.••• •.-.••-.• .'o-.;1.;-.;:•/•• •.-.•' ••.•.••.*..••.*•.-:-•;»•..•••.•.•
v^;J;r:V-;:^>;/::;-;.;f;s.-:•:;::.>•••'°'' " °••••;•:•>-.;• .;,'•' " ••••v.v-.'r'.o.*.-
a '• ; '-'•; -.„'.,•.'•. .*i •'•-'•. *.°'.'o •'•" '
." ',. '!>'.'• ••'••.;»•." •..;'<>••.' • ' "
- •-°
,. -^.-Y ..-o...;.:•
•- - • i». •-.«.-•'•
, Facility Boundary
• Elevation
Feet(MSL)
3110
-3100
r-3090
r 3080
r 3070
-3060
3050
-3040
r3030
h 3020
h 3010
- 3000
LEGEND
[*!•'$ Silty Sand
::::'-:'j Fine Sand
.'•*. j Silty Sand and Fine to
Medium Sand
Horizontal
0 500 1000
Scale, Feet
FIGURE 5-2. GEOLOGIC CROSS SECTION A-A'
-------
OSWER Directive 9481.00-11
installed to the east and west, as well as onsite, to assess vertical components of
ground-water flow (note N-1 and N-2 in Figure 2-2 and other sets of paired weils in
Figure 2-1). In addition, 13 compliance monitoring wells were installed (designated
CW in Figure 5-1). Ground-water elevations are presented in Table 5-1 and as a
water table contour map (Figure 5-3).
• TABLE 5-1.
GROUND-WATER ELEVATIONS (1987)
Well
MW-1
MW-2
MW-3
MW-4
MW-5
MW-6
MW-7
MW-8
MW-9
MW-10
MW-11
MW-1 2
MW-1 3
MW-1 4
MW-1 5
MW-1 6
Elevation
(ft,MSL)
3080.57
3085.08
3085.07
3060.61
3060.60
3053.51
3051.42
3072.37
3077.65
3077.63
3056.67
3060.80
3051.41
3061.13
3061.11
3068.80
Well
MW-17
MW-1 8
MW-1 9
MW-20
MW-21
MW-22
MW-23
MW-24
MW-25
MW-26
MW-27
MW-28
MW-29
MW-30
MW-31
MW-32
Elevation
(ft,MSL)
3060.75
3066.16
3066.59
3066.71
3060.22
3075.10
3067.31
3065.75
3073.57
3066.36
3070.21
3079.31
3074.74
3077.41
3075.83
3024.53
Well
MW-33
CW-1
CW-2
CW-3
CW-4
CW-5
CW-6
CW-7
CW-8
CW-9
CW-10
CW-11
CW-1 2
CW-1 3
Elevation
(ft.MSL)
3026.89
3077.25
3074.74
3076.30
3081.42
3080.35
3080.23
3079.96
3079.46
3072.45
3071.12
3071.22
3071.04
3070.58
Water elevation data indicate that the average depth of ground water
beneath the site is 25 feet, and ground water flows to the west on a gradient of
approximately 0.0065 ft/ft. The nested monitoring wells (e.g., MW-4, 5, MW-9, 10,
MW-7, 13, and MW-14, 15) indicate that ground water flows nearly horizontally
beneath the site with a small downward component. The hydraulic gradient and
5-5
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OSWER Directive 9481 00-11
LEGEND
• Compliance Well
D Monitoring Well
Facility Boundary
/ Contour, Water
85 Table Elevation,
/ Feet (MSL)
•^—Flow Line
Note: Actual elevation
equals map value
plus 3000 feet.
500 1000
-i
Scale, Feet
FIGURE 5-3. WATER TABLE CONTOURS
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OSWER Directive 9481 00-11
other properties of the uppermost aquifer (discussed in the sections that follow) are
presented in Table 5-2. Detailed descriptions of the characteristics of the aquifers
beneath the facility are presented in Section D of the Part B permit application.
,TABLE 5-2.
SUMMARY OF AVERAGE PROPERTIES OF THE UPPERMOST AQUIFER
Property
Description/Value
Hydrostratigraphy
Depth to Water Table
Gradient
Hydraulic Conductivity
Effective Porosity
Flow Velocity
Alluvial fan desposits;
unconsplidated silty sands and fine
to medium sands
20 to 30 ft
0.0075 to 0.008 ft/ft
1.7x 10-3 cm/sec
0.21 (no units)
0.161 ft/day
Offsite, the water table was observed to be at least five feet deep within two
miles downgradient of the site. Downward flow components are present in the
eastern hills as shown by the lower piezometric heads measured in the deeper
piezometer at N-1. Both field observations in the center of the basin and a review
of aerial photographs indicate that little or no surface discharge of ground water
occurs. The highest water levels were observed in 1982. Because 1982 had the
highest precipitation in over 100 years of records for this area, water table
elevations are not expected to rise significantly above these levels.
There is a confined bedrock aquifer at depth separated from the uppermost
aquifer by about 370 feet of relatively impermeable limestone, siltstone and other
bedrock units.
5.3.1 Background Water Quality
The background water quality (i.e., in the uppermost aquifer) is highly saline.
Water samples taken from the monitoring wells had TDS of approximately 20,000
5-7
-------
OSWER Directive 9481.00-11
mg/l. Salinity tends to be greater in the lower lying areas beneath the site. On a
regional scale, salinity also increases toward the center of the basin (west of the
site). Additional information is provided in Section D of the Part B permit
application.
5.3.2 Hydraulic Conductivity "
Hydraulic conductivity values of the uppermost aquifer have been determined
by conducting in situ aquifer tests in 14 monitoring wells. Pump tests were
conducted at wells MW-4 and MW-18 while monitoring the head response at wells
MW-26 and MW-19, respectively. Slug tests were conducted at wells MW-1, MW-2,
MW-5, MW-8, MW-11, MW-17, MW-22, MW-24, MW-29, and MW-30. Data were
analyzed using the Cooper-Jacob straight line method for pump tests (Cooper and
Jacob, 1946) and the Bouwer & Rice method for slug tests (Bouwer, 1978). Table 5-3
summarizes the hydraulic conductivity values obtained for each well. The resultant
values are consistent, ranging from 4.5 x 10-3 cm/sec for the fine to medium sands to
2.2 x 10-4 cm/sec for the sandy silts. The geometric mean is 1.7 x 10-3 cm/sec. Bouwer
(1978) suggests that the geometric mean can usually be used to represent the
central tendency of a set of hydraulic conductivity data.
5.3.3 Effective Porosity
Effective porosity of an aquifer material corresponds to the specific yield
under unconfined conditions. The interpretation of the results from the in situ
aquifer (pump) tests at the site indicated specific yields of 0.23 and 0.19. Therefore,
the average effective porosity of the aquifer matrix is estimated to be 0.21. This
value is comparable to published values for sandy silts and fine to medium sands.
5-8
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OSWER Directive 9481 00-11
TABLE 5-3.
AQUIFER TEST RESULTS
A. SLUG TEST
Well
MW-1
MW-2
MW-5
MW-8
MW-11
MW-1 7
MW-22
MW-24
MW-29
MW-30
Data Analysis Method
Bouwer & Rice
Bouwer & Rice
Bouwer & Rice
Bouwer & Rice
Bouwer & Rice
Bouwer & Rice
Bouwer & Rice
Bouwer & Rice
Bouwer & Rice
Bouwer & Rice
Hydraulic Conductivity
(cm/sec)
3.5x10-3
4.0x10-3
3.1x10-3
5.3x10-4
7.0x10-4
4.5x10-3
2.2x10-4
4.0x10-3
3.1x10-3
4.4 x 10-4
B. PUMP TEST
Well
MW-4
MW-26
MW-1 8
MW-1 9
Well Type Data Analysis Method HydraulkConductivity
Pumping well
Observation well
Pumping well
Observation well
Cooper-Jacob
Cooper-Jacob
Cooper-Jacob
Cooper-Jacob
1.7x10-3
3.3x10-3
4.0x10-3
8.9x10-4
5-9
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OSWER Directive 9481 00-1
6.0 EXPOSURE PATHWAYS
The potential exposure pathways of ground-water contaminants at Facility F
are limited. The uppermost aquifer, described in Table 5-1, is not a source of
•y
drinking water because of its high TDS content (greater than 20,000 ppm); it meets
the definition of a Class III aquifer established in EPA's ground-water protection
strategy (EPA, 1984). Furthermore, the State Water Control Board limits its use to
non-potable industrial and domestic sewage purposes only.
6.1 Potential Human Exposure
The uppermost aquifer is not used for domestic drinking water or agricultural
purposes. Water for these uses is obtained from the deeper, confined (bedrock)
aquifer. This deeper aquifer is separated from the uppermost aquifer by about 370
feet of relatively impermeable bedrock units and is therefore not considered
vulnerable to contamination from the upper aquifer.
Water from the uppermost aquifer is used only in heat pumps. The heat
pumps are closed systems and should not result in any adverse exposures.
6.2 Potential Environmental Exposure
The uppermost aquifer does not appear to discharge to the surface in the
vicinity of Facility F. The absence of nearby agricultural lands and habitat for
endangered or threatened species (Section 4-1), as well as surface waters, precludes
these exposure pathways.
6.3 Reference Exposure Levels
Five hazardous constituents, mercury, methylene chloride, toluene, TCA and
TCE, have been detected at Facility F. The discussion that follows develops exposure
levels for each of these five constituents. These exposure levels are provided as
reference points, even though no human exposure could occur.
6-1
-------
OSWER Directive 9481.00-11
Part I of the ACL guidance document (EPA, 1987a) indicates that Maximum
Contaminant Levels (MCLs) take precedence when establishing exposure levels for
the drinking water pathway. MCLs were developed under the Safe Drinking Water
Act (PL 93-523) for contaminants that may have an adverse effect on human health.
MCLs are "the maximum permissible level of a contaminant in water which is
delivered to any user of a public water system" (PL 93-523; Section 1401(3)). The
MCLs for mercury and TCE are 0.002 and 0.005 mg/l, respectively (EPA, 1980; 1982;
1987b).
Methylene chloride, TCA, and toluene are considered systemic toxicants.
Exposure levels are calculated for systemic toxicants for which MCLs are not
available using the oral reference dose (RfD; EPA, 1986). An exposure assumption
of a 70 kg adult consuming two liters of water per day is used. The following
formula is used to calculate the systemic exposure concentration (EPA, 1987a):
C systemic, mg/l = Rf D * 70 ^ (6-1)
2 I/day
Methylene chloride and TCA are also considered carcinogenic.-Potency factors
(PF), or slope factors, are used to estimate hazardous constituent exposure levels
that correspond to statistical lifetime excess cancer risk values. These factors are
used for the carcinogens methylene chloride and TCA, for which MCLs are not
available. For example, a contaminant concentration corresponding to an
incremental lifetime cancer risk of 10-4 (which is within the range EPA generally
considers acceptable), assuming a 70 kg adult consuming two liters of water per
day, is estimated by the following formula:
r .. 70 kg x 10-4
^carcinogenic* mg/l = (6-2)
2l/dayxPF
A 10-4 risk level was used for comparative purposes for methylene chloride and TCA
because of the high salinity of the ground water under the facility.
Table 6-1 presents reference human health exposure concentrations based on
MCLs and equations 6-1 and 6-2.
6-2
-------
OSWER Directive 9481.00-11
TABLE 6-1.
REFERENCE HUMAN HEALTH EXPOSURE LEVELS
Constituent
(CAS No.)
Mercury
(7439-97-6)
Methylene Chloride
(75-09-2)
Toluene
(108-88-3)
1 , 1 ,2-Trichloroethane
(79-00-5)
Trichloroethylene
(79-01-6)
MCL .
(mg/l) .
0.002
—
—
—
0.005
RfD(a)
—
0.060
0.300
0.200
—
PF(b)
—
0.014
—
0.057
--
Exposure LevelW
(mg/l)
(eq6-1)
--
2.1
1.05
7.0
—
(eq 6-2)
--
0.25
—
0.061 "
—
a) Verified reference dose, mg/kg/day.
b) Carcinogenic potency factor, or slope factor, [mg/kg/day]-1.
c) Equations 6-1 and 6-2 discussed in text; a risk value of 1O4 used in
equation 6-2.
6-3
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OSWER Directive 9481.00-11
7.0 CONTAMINANT TRANSPORT ANALYSIS
This section provides a model for the change in contaminant concentrations in
the three plumes of hazardous constituents migrating across the site. The analytical
ground-water model estimates the advection/dispersion of the contaminants,
taking adsorption into consideration, and assumes a finite, fully-penetrating, two-
dimensional source with dominating regional flow. The solute source entrance rate
is considered negligible in relation to the uniform regional flow rate; transverse
dispersion dominates; and the solute entrance rate is continuous and constant
(Walton, 1984, p. 11.51). These assumptions are conservative for assessing the
dispersion properties of the aquifer for the contaminants indicated.
Ground water beneath the site is characterized by uniform, unconfined flow
through sandy alluvial fan deposits. As indicated by the in situ aquifer test results,
the hydraulic properties within the aquifer are relatively homogeneous. Ground
water flows under low hydraulic gradient (0.005 to 0.008). The plumes of the
hazardous constituents (Figures 3-1 through 3-4) from three source areas follow the
ground-water flow direction, widening as they move across the site, as indicated by
the constituent concentration isopleths. This is consistent with advection/dispersion
properties of fine-grained aquifers under low hydraulic gradient conditions.
The three primary sources of contaminants appear to be:
• The wastewater treatment pond - mercury;
• The landfill disposal cell 1 - methylene chloride, toluene, TCA, and TCE;
and
• The past disposal unit - methylene chloride, TCA, and TCE.
7.1 Relative Flow Velocities of Constituents
The average linear velocity of ground-water flow, V, is calculated from the
following equation:
7-1
-------
OSWER Directive 9431 00-1
v = (7-1;
where: K = hydraulic conductivity, cm/sec
I = hydraulic gradient, ft/ft
n = effective porosity, unitless.
The hydraulic gradient was calculated as the geometric mean of all the
hydraulic conductivities (Section 5.3.2). Due to the relative homogeneity of the
aquifer matrix, varying only between fine to medium sands and sandy silts, this is a
conservative, yet realistic, value that was ca:ulated to be 1.7x 10-3 cm/sec. Effective
porosity for the aquifer was determined to oe 0.21 from the in situ aquifer testing
(Section 5.3.3). The ground-water gradients were measured from the ground-water
contour map (Figure 5-3). The gradient in the southeast portion of the property is
0.0054 and in the northeast is 0.008. The corresponding average ground-water
velocities are 0.123 and 0.183 ft/day.
The relative flow velocity of each retarded constituent was calculated by the
following equation (Walton, 1984, p. 12.15):
V
vc = (7-2)
1 +
where: \»c = Relative flow velocity of the retarded constituent, ft/day
Pb = Bulk density, g/cm3
Kd s Distribution coefficient, ml/g
n s Effective porosity, unitless.
The bulk density of 1.7 g/cm3 was determined from laboratory tests of
representative samples collected from soil borings drilled into the aquifer. The
effective porosity remains 0.21. Distribution coefficients for the volatile organic
ground-water contaminants range between 10-4 and 10-2 ml/g, due to the solubility
and relatively high mobility. The distribution coefficients for the inorganic
7-2
-------
OSWER Directive 9481.00-11
contaminants conservatively range between 10-2 and 1 ml/g (Walton, 1984, Figure
12.2A). The distribution coefficients were geometrically averaged to yield
conservative results. The parameters for the northeastern and southeastern
portions of the site are shown in Table 7-1.
-TABLE 7-1.
PARAMETERS FOR RELATIVE FLOW VELOCITY
Location/
Constituents
Southeast portion of site;
organics
Northeast portion of site;
inorganics
I
(ft/ft)
0.0054
0.008
V
(ft/day)
0.123
0.183
Kd
(ml/g)
0.0001
0.001
0.01
0.01
0.1
1.0
vc
(ft/day)
0.123
0.122
0 114
0.169
0.101
0.020
Relative flow velocities for the northeast and southeast portions of the site
were geometrically averaged to yield a realistic estimate of an average vc/ which
under field conditions varies due to the micro heterogeneities within the aquifer
media. Geometrically averaging the relative flow velocities results in a relative flow
of 0.120 ft/day for the volatile organics in the southeast portion of the site and
0.070 ft/day for the inorganics in the northeast portion of the site.
7.2
Dispersivitv
Dispersivity is the ability of a porous material to mechanically disperse solutes.
The coefficient of mechanical dispersion (taking adsorption into consideration) is a
function of the relative flow velocity of the retarded constituent (Walton, 1984, p.
11.4):
D a avcN
(7-3)
where:
D = coefficient of mechanical dispersion, ft2/day
a = dispersivity, ft
7-3
-------
OSWER Directive 9481.00-11
vc = relative flow velocity of the retarded constituent, ft/day
N = empirically determined constant between 1 and 2. Assumed
to be 1 for isotropic granular porous materials.
A linear dependency equation relating longitudinal dispersivity, LcN = coefficient of mechanical transverse dispersion, ft2/day.
7-4
-------
OSWER Directive 9481 00-11
7.4 Modeled Concentrations
Equation 7-5 was used to calculate the concentrations of the five hazardous
constituents at the property boundary and 2500 feet beyond the boundary. The
initial source concentrations, C0, Were based on maximum concentrations observed
in compliance wells, although tHe maximum concentrations from a re'ease may
possibly exceed this value. The width of the source was based on a consideration of
the plume size at the source and the width of the source unit. Input values for
source width and distance to the facility boundary, with calculated results, are
provided in Table 7-2. The most protective of the human health exposure
concentrations presented in Table 6-1 are also presented in Table 7-2 for
comparison.
This model can be seen to reasonably represent the plumes by comparing the
calculated values of Caa at the property boundary to the actual values. For instance,
the calculated value for the mercury at the boundary is 0.005 mg/l; the measured
value at the closest well is 0.006 mg/l. Where concentrations at the boundary are
likely the result of two sources (for instance, at MW-14), the calculated values must
be summed to be compared to the actual values at the boundary. For example, the
calculated concentrations of TCA at the boundary for the two sources is 0.004 plus
0.011, or 0.015; the actual value at the nearest well, MW-14, is 0.012.
The representativeness of the model may be attributed to the
representativeness of the parameters. The model used the best estimates of the
values for all the parameters. The parameters used to calculate the average
ground-water velocity, V, were determined from site measurements. The value
used for the hydraulic conductivity,
-------
OSWER Directive9481.00-II
maximum measured concentration in the source area was used as the initial
concentration, C0. The coefficient of mechanical transverse dispersion, DT/ was
calculated from representative values in the literature. The model used takes
adsorption into consideration. Biodegradation and volatilization were not
considered.
TABLE 7-2.
CALCULATED CONCENTRATIONS
Source
Landfill Disposal
Cell 1
Lsb = 275 ft
X * 3660 ft
to boundary
Past Disposal
Unit
1^, = 250 ft
X= 1900 ft
to boundary
Wastewater
Treatment Pond
1,6= 125 ft
X = 2700 ft
to boundary
Constituent
Methyl ene
Chloride
Toluene
TCA
TCE
Methyl ene
Chloride
TCA
TCE
Mercury
Source
Concen-
tration*
(mg/l)
0.009
1.850
0.026
0.150
0.007
0.046
0.170
0.036
Site Boundary
-------
OSWER Directive 9481 00-11
8.0 DEVELOPMENT OF ACLs
This section presents the development of the proposed alternate
concentration limits (ACLs) for this demonstration. The ACLs are based on the
analysis of potential exposure pathways and human health exposure concentrations
developed in Section 6 and the contaminant transport analysis presented in
Section 7.
As noted in Section 6, the potential pathways for human exposure (via
ingestion and heat pumps) were dismissed. The use of the uppermost aquifer for
drinking water or agricultural purposes is highly unlikely because the ground water
in the aquifer exhibits natural TDS values greater than 20,000 mg/l and, hence, is
unsuitable for these purposes. Although the aquifer is used for heat pumps, this use
will not result in human exposures because heat pumps are closed systems. Tfiis
aquifer is also separated from the deeper aquifer by 370 feet of rock of low
permeability.
Adverse environmental exposure is also precluded by the surrounding land use
and lack of discharge of ground water from the uppermost aquifer to surface
features. The contaminant'plumes are moving away from Towns A and B and
toward the playa that occupies most of the regional structural basin. The area
surrounding the facility contains very little vegetation or useful habitat. The Fish
and Wildlife Service has concluded that threatened and endangered species are not
found in the vicinity of Facility F.
The contaminant transport analysis presented in Section 7 developed
conservative dispersion factors (Co/Caa) that can be used to estimate plume
attenuation between the source and points of interest at or beyond the site
boundary. These dispersion factors, presented in Table 7-1, show 4- to 7-fold
reduction in plume concentration between the leaking hazardous waste
management unit and the property boundary. The plumes are predicted to be
between 0.08 and 0.11 times their original concentration 2,500 feet beyond the
facility boundary, partially as a function of the location of the source within the
facility.
8-1
-------
OSWER Directive 9481.00-11
Table 7-1 further illustrates that the concentration of the hazardous
constituents are near or below reference human health exposure levels at the
boundary of Facility F. Mercury leaking from the wastewater treatment lagoon in
the northeastern portion of the site is expected to exhibit concentrations below the
MCL of 0.002 mg/l within about one mile of the boundary. Contaminant levels for
TCE leaking from the past disposal site in the southwestern portion of the site are
expected to reach the MCL of 0.005 mg/l within about 7 miles of the facility's
boundary. These estimates are based on the conservative assumptions thought best
to model the actual plume, as discussed in Section 7.
Based on the absence of exposure pathways and the attenuation of the
contaminant plumes described above, it is proposed that the ACLs be established at
the current levels at the POCs. The proposed ACLs are listed below in Table 8-1:
TABLE 8-1.
PROPOSED ALTERNATE CONCENTRATION LIMITS
Constituent
Mercury
Methylene Chloride
Toluene
1,1,2-Trichloroethane
Trichlorethylene
Proposed ACL (mg/l)
0.036
0.009
1.85
0.046
0.170
The State Department of Environmental Control has reviewed this
demonstration and concurs with the proposed ACLs. The State, which controls the
land adjacent to Facility F, has agreed to limit any use of the ground water in the
uppermost aquifer to heat pumps. This should pose no problems as, at present,
there are no plans by the State or others to develop these lands.
8-2
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OSWER Directive 9481 00-11
9.0 GROUND-WATER MONITORING AND SOURCE REDUCTION MEASURES
9.1 Ground-Water Monitoring
T
Aground-water monitoringprogram has been in effect at Facility F since 1981.
There are 13 compliance monitoring wells at the downgradient edges of the three
waste management units that have leaked. There are an additional 25 onsite
monitoring wells. Well locations are shown on Figures 2-1 and 2-2.
Compliance monitoring will continue at the 13 compliance wells under 40 CFR
Part 264. The compliance monitoring system is described in detail in Section F of the
Part B permit application. All compliance wells will be monitored quarterly for the
five hazardous constituents that have been detected (mercury, methylene chloride,
j,
toluene, TCA and TCE). The wells will be monitored annually for Appendix IX
constituents.
The other onsite monitoring wells will be sampled and analyzed annually for
the five hazardous constituents to monitor the plumes of contaminants. Additional
offsite wells will be installed to monitor contaminant migration offsite (Section F of
the Part B permit application). Two offsite wells are being constructed at the
northeast corner of the facility to monitor progression of the mercury plume.
9.2 Source Reduction Measures
Measures have been taken to reduce the quantities of waste disposed at the
facility by implementing two source reduction processes: solvent recovery and
mercury precipitation. These processes are described in detail in Section M of the
Part B permitapplication.
9-1
-------
OSWER Directive 9481.00-
REFERENCES
Bouwer, H., 1978. Groundwater Hydrology, McGraw-Hill, New York, pp. 90-117
Cooper, H. H., and C. E. Jacob, 1946..-A Generalized Method for Evaluating
Formation Constants and Summarizing Well Field History," Transactions of the
American Geophysical Union. Vol. 27, pp. 526-534.
EPA (U.S. Environmental Protection Agency), 1980. "Environmental Protection
Agency National Primary Drinking Water Regulations, 40 CFR Parts 141, Subpart
B," Federal Register, v. 45, 47342, August 17.
EPA (U.S. Environmental Protection Agency), 1982. "Environmental Protection
Agency National Primary Drinking Water Regulations, 40 CFR Parts 141, Subpart
B," Federal Register, v. 47.10998. March 12.
EPA (U.S. Environmental Protection Agency), 1984. Ground-Water Protection
Strategy. Office of Ground-Water Protection, Washington, D.C., August.
EPA (U.S. Environmental Protection Agency), 1986. Verified References Doses
(RfDs)oftheU.S. EPA. ECAO-CIN-475, Cincinnati, Ohio, January.
EPA (U.S. Environmental Protection Agency), 1987a. Alternate Concentration Limit
Guidance. Part 1 - ACL Policy and Information Reguirements. EPA/530-SW-87-
017, Washington, D.C.July.
EPA (U.S. Environmental Protection Agency), 1987b. "Environmental Protection
Agency National Primary Drinking Water Regulations, 40 CFR Parts 141, Subpart
G," Federal Register, v. 52, 25712, July 8.
Walton, W. C., 1984. "Practical Analysis of Well Hydraulics and Aquifer Pollution".
Handbook of Analytical Ground-Water Models, Short Course, April 9-13,
International Ground Water Modeling Center.
R-1
-------
OSWER Directly*941
Other Resource Documents
U.S. Environmental Protection Agency, Health Effects Assessment for Methylene
Chloride, ECAO-CIN-HO-28, Environmental Criteria and Assessment Office,
Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Final Guidelines for Estimating
Exposures. Federal Register SI: 34042-34054, September 24,1986.
U.S. Environmental Protection Agency, Health Effects Assessment for Toluene.
ECAO-ClN-HO-33, Environmental Criteria and Assessment Office, Cincinnati,
Ohio, September, 1984.
U.S. Environmental Protection Agency, Health Effects Assessment for 1,1.2.-
Trichloroethane, ECAO-CIN-HO-04, Environmental Criteria and Assessment
Office, Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Health Effects Assessment for
Trichloroethylene. ECAO-CIN-HO-46, Environmental Criteria and Assessment
Office, Cincinnati, Ohio, September, 1984.
U.S. Environmental Protection Agency, Quality Criteria for Water. 1986.
EPA;440-5-86-001, Washington, D.C., May 1,1986.
U.S. Environmental Protection Agency, Final Guidelines for Estimating Exposures,
Federal Register 51: 34042-34054, September 24,1986.
U.S. Environmental Protection Agency, Water Quality Documents, Availability,
Federal Register 45: 79318-79357, November 1980.
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December 1979.
R-2
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OSWER Directive 9481.00-11
APPENDIX A
LOCATION OF INFORMATION IN THE CASE STUDY
SUPPORTING THE 19 REGULATORY CRITERIA
UNDER §264.94(b)(1) and §264.94(b)(2)
A-1
-------
OSWER Directive 9481 00-1
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
Criteria for Assessing Potential Adverse Effects on . r. r <-»,, .
Ground-Water Quality: cf,*- S y
§264.94(b)(1) Section No.
(i) The physical and chemical characteristics of the 3.1,3.2
waste in the regulated unit, including its
potential for migration;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3
facility and surrounding land;
(iii) The quantity of ground water and the direction 5.3
of ground-water flow;
(iv) The proximity and withdrawal rates of ground- 4.2
water users;
(v) The current and future uses of ground water in 4.1,4.2
the area;
(vi) The existing quality of ground water, including 3.2
other sources of contamination and their
cumulative impact on the ground-water
quality;
(vii) The potential for health risks caused by human 6.1,6.3
exposure to waste constituents;
(viii) The potential damage to wildlife, crops, 6.2,6.3
vegetation, and physical structures caused by
exposure to waste constituents;
(ix) The persistence and permanence of the 3.1,3.2,6.1,6.2
potential adverse effects;
A-2
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OSWER Directive 9481.00-11
LOCATION OF INFORMATION SUPPORTING THE 19 REGULATORY CRITERIA
(Continued)
Criteria for Assessing Potential Adverse Effects on ACL c c.udx/
Hydraulically-Connected Surface-Water Quality: cTiinn, NO
§264.94(b)(2) v 3e«.on NO.
(i) The volume and physicaKand chemical 3.1,3.2
characteristics of the waste in the regulated
unit;
(ii) The hydrogeological characteristics of the 5.1,5.2,5.3
facility and surrounding land;
(iii) The quantity and quality of ground water, and 5.3
the direction of ground-water flow;
(iv) The patterns of rainfall in the region; 4.3
(v) The proximity of the regulated unit to surface 4.2
waters;
(vi) The current and future uses of surface waters in 4.1,4.2
the area and any water quality standards
established for those surface waters;
(vii) The existing quality of surface water, including 3.2
other sources of contamination and the
cumulative impact on surface water quality;
(viii) The potential for health risks caused by human 6.1, 6.3
exposure to waste constituents;
(ix) The potential damage to wildlife, crops, 6.2,6.3
vegetation, and physical structures caused by
exposure to waste constituents; and
(x) The persistence and permanence of the , 3.1,3.2,6.1,6.2
potential adverse effects.
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OSWER Directive 9481.00-11
: APPENDIX B
CHEMICAL AND PHYSICAL PROPERTIES1 AND IRIS (INTEGRATED
RISK INFORMATION SYSTEM) DATA BASE FOR MERCURY,
METHYLENECHLORIDE,TOLUENE.1,1,2-TRICHLOROETHANE,
AND TRICHLOROETHYLENE
1 Adapted from: Chemical, Physical and Biological Properties of Compounds Present
at Hazardous Waste Sites. Final Report, Office of Waste Programs Enforcement
(OWPE) and Office of Solid Waste and Emergency Response (OSWER), U.S. EPA,
September 27, 1985.
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OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
MERCURY
Summary
Both organic and inorganic-forms of mercury are reported to be teratogenic
and embryotoxic in experimental animals. In humans, prenatal exposure to
methylmercury has been associated with brain damage. Other major target organs
for organic mercury compounds in humans are the central and peripheral nervous
system and the kidney. In animals, toxic effects also occur in the liver, heart,
gonads, pancreas, and gastrointestinal tract. Inorganic mercury is generally less
acutely toxic than organic mercury compounds, but it does affect the central
nervous system adversely.
Background Information
Several forms of mercury, including insoluble elemental mercury, inorganic
species, and organic species, can exist in the environment. In general, the
mercurous (+ 1) salts are much less soluble than the more commonly found mercuric
( + 2) salts. Mercury also forms many stable organic complexes that are generally
much more soluble in organic liquids than in water. The nature and solubility of the
chemical species that occur in an environmental system depend on the redox
potential and the pH of the environment.
Chemical and Physical Properties (Metal)
CAS Number: 7439-97-6
Chemical Formula: Hg
IDPACName: Mercury
Atomic Weight: 200.59
Boiling Point: 356.58°C
Melting Point: -38.87°
Specific Gravity: 13.5939 at 20°C
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OSWER Directive 9481.00-11
Solubility in Water: 81.3 ug/liter at 30°C; some salts and organic compounds
are soluble
Solubility in Organics: Depends on chemical species
Vapor Pressure: 0.0012 mm Hg at 20°C
FlashPoint: Not Flammable
Transport and Fate
Mercury and certain of its compounds, including several inorganic species and
dimethyl mercury, can volatilize to the atmosphere from aquatic and terrestrial
sources. Volatilization is reduced by conversion of metallic mercury to complexed
species and by deposition of HgS in reducing sediments, but even so atmospheric
transport is the major environmental distribution pathway for mercury.
Precipitation is the primary mechanism for removal of mercury from the
atmosphere. Photolysis is important in some aquatic systems. Adsorption onto
suspended and bed sediments is probably the most important process determining
the fate of mercury in the aquatic environment. Sorption is strongest into organic
materials. Mercury in soils is generally complexed to organic compounds.
Virtually any mercury compound can be remobilized in aquatic systems by
microbial conversion to methyl and dimethyl forms. Conditions reported to
enhance biomethylation include large amounts of available mercury, large numbers
of bacteria, the absence of strong complexing agents, near neutral pH, high
temperatures, and moderately aerobic environments. Mercury is strongly
bioaccumulated by numerous mechanisms. Methylmercury is the most readily
accumulated and retained form of mercury in aquatic biota, and once it enters a
biological system it is very difficult to eliminate.
Health Effects
When administered by intraperitoneal injection, metallic mercury produces
implantation site sarcomas in rats. No other studies were found connecting mercury
exposure with carcinogenic effects in animals or humans. Several mercury
compounds exhibit a variety of genotoxic effects in eukaryotes. In general, organic
mercury compounds are more toxic than inorganic compounds. Although brain
damage due to prenatal exposure to methylmercury has occurred in human
8-3
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OSWER Directive 9481.00-11
populations, no conclusive evidence is available to suggest that mercury causes
anatomical defects in humans. Embryotoxicity and teratogenicity of methylmercury
has been reported for a variety of experimental animals. Mercuric chloride is
reported to be teratogenic in experimental animals. No conclusive results
concerning the teratogenic effects of mercury vapor are available.
In humans, alkyl mercury compounds pass through the blood brain barrier and
the placenta very rapidly, in contrast to inorganic mercury compounds. Major
target organs are the central and peripheral nervous systems, and the kidney.
Methylmercury is particularly hazardous because of the difficulty of eliminating it
from the body. In experimental animals, organic mercury compounds can produce
toxic effects in the gastrointestinal tract, pancreas, liver, heart, and gonads, with
involvement of the endocrine, immunocompetent, and central nervous systems.
Elemental mercury is not highly toxic as an acute poison. However, inhalation
of high concentrations of mercury vapor can cause pneumonitis, bronchitis, chest
pains, dyspnea, coughing, stomatitis, gingivitis, salivation, and diarrhea. Soluble
mercuric salts are highly poisonous on ingestion, with oral LOso values of 20 to 60
mg/kg reported. Mercurous compounds are less toxic when administered orally.
Acute exposure to mercury compounds at high concentrations causes a variety of
gastrointestinal symptoms are severe anuria with uremia. Signs and symptoms
associated with chronic exposure involve the central nervous system and include
behavioral and neurological disturbances.
Standards and Criteria
National Primary Drinking Water Standard (U.S. EPA):
MCL: 0.002 mg/liter
Ambient Water Quality Criteria (U.S. EPA):
Aquatic Life
Freshwater
Acute toxicity: 2.4 yg/liter
Chronictoxicity: 0.012 ug/liter
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OSWER Directive 9481.00-11
Marine
Acute toxicity: 2.1 yg/liter
Chronic toxicity: 0.025 ug/liter
Human Health
Water and Fish Ingestiort: 144ng/liter
Fish Ingestion Only: , 146ng/liter
Others
NIOSH Recommended Standard: 0.05 mg/m3 TWA (inorganic mercury)
OSHA Standard: 0.1 mg/m3 Ceiling Level
ACGIH Threshold Limit Values:
0.01 mg/m3 TWA (alkyl compounds)
0.03 mg/m3 STEL (alkyl compounds)
0.05 mg/m3 TWA (vapor)
0.1 mg/m3 TWA (aryl and inorganic compounds)
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OSWER Directive 9481.00-1
ACL
CASE STUDY 5
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OSWER Directive 9481 00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Mercury; CAS No. 7439-97-6 (Revised 01/11/1986)
I. CHRONIC SYSTEMIC TOXIC-IT*: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical:
CAS No.:
Mercury
7439-97-6
Preparation Date: 01/09/86
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect
Renal and kidney
damage
Experimental Doses * UF MF
40ppmofdiet 1000
converted to 2 mg/kg
bw/day (LOAEL)
RfD
0.002
mg/kg/day
or
0.1 mg/day
fora
70 kg man
Rat oral chronic
study
Fitzhugh etal.
(1950)
NOAEL: None
* Dose Conversion Factors & Assumptions: Food consumption 5% body weight;
thus, 40 mg/kg of diet (i.e.,40 ppm) x 0.05 kg of diet/kg bw/day = 2 mg/kg/dfay
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OSWER Directive 9481.00-11
2. PRINCIPAL AND SUPPORTING STUDIES
Fitzhugh, O.G., A.A. Nelson, E.P. Laug and P.M. Kunze. 1950. Chronic toxicities
of mercuric phenyl and mercuric salts. Arch. Ind. Hyg. Occup. Med. 2: 433-441.
This is the only 'chronic ingestion study designed to evaluate the toxicity of
inorganic mercury salts. In this study, rats of both sexes (20-24/ group) were given
0.5,2.5,10,40 or 160 ppm mercu/y acetone for up to 2 years. Assuming food
consumption was equal to 5 % bw/day, the daily intake was equal to 0.025, 0.125,
0.5,2.0 and 8.0 mq/kg bw, respectively. Detailed microscopic evaluation of various
tissues indicated that only the kidney was affected to any degree with lesions in the
promixal convoluted tubules and cortex. Treatment-related changes did not appear
to be present at doses less than 40 ppm.
Also, it was noted that the damage occurring at these lower doses was present
to some degree in older control animals. The 40 ppm feeding level was identified as
a LOAEL in this study. Although it appears that the 10 ppm feeding level, as well as
the two lower doses, may have been a NOAEL the descriptive manner in which the
data are presented makes it difficult to adequately evaluate the histopathological
data for these doses. As a result of this uncertainty and since the use of the 40 ppm
LOAEL will result in a somewhat more protective estimate than a 10 ppm NOAEL,
the 40 ppm LOAEL is chosen as the basis for an ADI calculation.
Short-term and subchronic studies were conducted by Bariety et al. (1971),
Druetetal. (1978), Weening et al. (1978) and Makker and Aikawa (1979). A NOAEL
of 50 ug/kg for antibody formation could be derived from the study of Druet et al.
(1978). However, this study is not chosen because the route of exposure was
subcutaneous injection, the immune response occurred only in a genetically
susceptible strain of rats and the duration of the study was only 8-12 weeks.
3. UNCERTAINTY AND MODIFYING FACTORS
Based upon these factors the Fitzhugh etal. (1950) study was considered most
appropriate for the development of an ADI. This study established a LOAEL of 2
mg/kg bw/day. Applying scaling factors of 100 to account for extrapolation from
animals to humans and differences in sensitivity among human population and an
additional 10 for concersion of a LOAEL to a NOAEL and ADI or 0.002 mg/kg/day or
0.1 mg/day for a 70 kg human was derived.
4. ADDITIONAL COMMENTS
The data base for this chemical is characterized by only one chronic ingestion
study with a small number of animals surviving past 18 months (10-24
animals/group). Short-term and subchronic studies by i.p. or s.c. exposures and
supporting epidemiological data are not well characterized.
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OSWER Directive 9481.00-11
5. CONFIDENCE IN THE RfD
Study: Medium DataBase: Medium RfD: Medium
Confidence in the study is rated medium as a medium amount of animals/sex
was used in each of five dose groups and several parameters were measured. The
NOAEL, however, was not well defined. Confidence in the data base is medium
because a small number of studies lends some support. Medium confidence in the
RfD follows. ;
6. DOCUMENTATION AND REVIEW
Limited Peer Review and Agency-wide Internal Review, 1984.
U.S. EPA. 1984. Health Effects Assessment Document for Mercury, Environmental
Criteria and Assessment Office, Cincinnati, OH.
Agency RfD Work Group Review: 08/05/85
Verification Data: 08/05/85
7. U.S. EPA CONTRACTS
Primary: C.T. DeRosa FTS/684-7534 or 513/569-7534
Office of Research and Development
Secondary: M.L. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
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OSWER Directive9481.00-II
RESOURCE DOCUMENTS FOR MERCURY
American Conference of Governmental Industrial Hygienists, Documentation
of the Threshold Limit Values. 4th ed, Cincinnati, Ohio, 1980,488 pp.
Bridger, M.A., and Thaxton, J.P., "Humoral immunity in the chicken as
affected by mercury," Arch-Environ. Contam.Toxicol. 12:45-49, 1983.
National Institute for Occupational Safety and Health, Registry
of Toxic Effects of Chemical Substances-Data Base. Washington, D.C., October
1983.
Shepard. T.H.. Catalog of Teratoqenic Agents, 3rd ed.. Johns Hopkins
University Press, Baltimore, 1980,410 pp.
-£•
U.S. Environmental Protection Agency, Ambient Water Qualiltv Criteria for
Mercury. EPA/440-5-80-058, Office of Water Regulations and Standards,
Criteria and Standards Division, Washington, D.C., October 1980.
U.S. Environmental Protection Agency, Health Effects Assessment for Mercury.
ECAO-CIN-HO-42, Environmental Criteria and Assessment Office, Cincinnati,
Ohio, September 1984.
U.S. Environmental Protection Agency, Quality Criteria for Water 1986, Update
No. 1. EPA/440-5-86-001, Office of Water Regulations and Standards,
Washington, D.C., 1986.
U.S. Environmental Protection Agency, Water-Related Environmental Fate of
129 Priority Pollutants. EPA/440-4-79-029, Washington, D.C., December, 1979.
Weast, R.E., ed. Handbook of Chemistry and Physics, 62nd ed., CRC Press,
Cleveland, Ohio, 1981, 2,332 pp.
World Health Organization, Environmental Health Criteria: 1. Mercury. World
Health Organization, Geneva,1976,131 pp.
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OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
METHYLENE CHLORIDE
Summary
CAS Number: 75-09-.2
Chemical Formula: CH2C12
IDPACName: Dichloromethane
Important Synonyms and Trade Names: Methylene dichloride, methane
dichloride
Chemical and Physical Properties
Molecular Weight: 84.93
Boiling Point: 40°C
Melting Point: -95.1°C
Specific Gravity: 1.3266 at 20°C
Solubility in Water: 13,200-20,000 mg/liter at 25°C
Solubility in Organics: Miscible with alcohol and ether
Henry's Law Constant: 3.19 x 10-3 atm-m3/mole at 25°C
Vapor Pressure: 362.4mm Hg at 20°C
Vapor Density: 2.93
Viscosity: 0.470 centipoise at 16°C
FlashPoint: Not Flammable
Log Octanol/Water Partition Coeffecient: 1.25
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OSWER Directive 9481 .QQ.1
Transport and Fate
Volatilization to the atmosphere appears to be the major mechanism for
removal of methylene chloride from aquatic systems and its primary evnironmental
transport process (EPA, 1979). Photooxidation in the troposphere appears to be the
dominant environmental fate of raethylene chloride. Once in the troposphere, the
compound is attacked by hydrbxyl radicals, resulting in the formation of carbon
dioxide, and to a lesser extent, carbon monoxide and phosgene. Phosgene is readily
hydrolyzed to HCL and CO2- About one percent of tropospheric methylene chloride
would be expected to reach the stratosphere where it would probably undergo
photodissociation resulting from interaction with high energy ultraviolet radiation.
Aerial transport of methylene chloride is partly responsible for its relatively wide
environmental distribution. Atmospheric methylene chloride may be returned to
the earth in precipitation.
Photolysis, oxidation, and hydrolysis do not appear to be significant
environmental fate processes for methylene chloride, and there is no evidence to
suggest that either adsorption or bioaccumulation are important fate processes for
this chemical. Although methylene chloride is potentially biodegradable, especially
by acclimatized microorganisms, biodegradation probably only occurs at a very slow
rate.
Standards and Criteria
Ambient Water Quality Criteria (U.S. EPA):
Aquatic Life
Freshwater
Acute toxicity: 11,000 ug/liter
Chronic toxicity: not available
Marine
Acute toxicity: 12.000 ug/liter
Chronic toxicity: 6,400 ug/liter
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OSWER Di recti ve 9481.00-11
Human Health
Water and Fish Ingestion: 0.19 ug/liter (10-6 risk level)
Fish Ingestion Only: 15.7 ug/liter (10-6 risk level)
Others
CAG Unit Risk (U.S. EPA):
1.4x10-2(mg/kg/day)-i
NIOSH Recommended Standards:
261 mg/m3 TWA in the presence of no more than 9.9 mg/m3 of CO 1,737
mg/m3/l 5 min Peak Concentration
OSHA Standards:
ACGIH Threshold Limit Values:
1,737mg/m3TWA
3,474 mg/m3 Ceiling Level
6,948 mg/m3 Peak Concentration (5 min in any
3hr)
350 mg/m3 TWA
1,740mg/m3STEL
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Methylene Chloride (Dichloromethane); CAS No. 75-09-2 (Revised 05/21/1987)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronictbxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Methylene Chloride
I. Chronic Systemic Toxicity: Noncarcinogenic Health Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Methylene Chloride
CAS No.: 75-09-2 Preparation Date. 06/13/86
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Liver toxicity NOAEL: 5.85 and 6.47 100 1 6E-2
mg/kg/day for males mg/kg/day
2-year rat drinking and females,
water bioassay respectively
National Coffee LOAEL: 52.58 and
Association (1982) 58:32 mg/kg/day for
males and-females,
respectively
* Dose Conversion Factors & Assumptions: none
2. PRINCIPAL AND SUPPORTING STUDIES
National Coffee Association. 24-Month chronic toxicity and oncogenicity study of
methylene chloride in rats. Final Report. Prepared by Hazleton Laboratories
America, Inc., Vienna, VA, August 11,1982.
The chosen study appears to have been very well conducted, with 85 rats/sex at
each of four dose groups. A high-dose recovery group of 25 rats/sex, as well as two
control groups of 85 and 50 rats/sex, was also tested. Many
effects were monitored.
The supporting data base is limited. A NOAEL of 87 mg/cu. m was reported in
one inhalation study (Haun et al., 1972). [The equivalent oral dose isabout 28 mg/kg
bw/day (i.e., 87 mg/cu. m x 0.5 x 0.223 cu. m/day/0.35 kg; these exposure values are
for rats).]
3. UNCERTAINTY AND MODIFYING FACTORS
UF = 100. (10ax10h) The 100-fold factor accounts for both the expected intra-and
interspecies variability to the toxicity of this chemical in lieu of specific data.
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OSWER Directive 9481.00-11
MF = 1
4. ADDITIONAL COMMENTS
None.
5. CONFIDENCE IN THE RfD
Study: High DataBase: Medium RfD: Medium
The study is given a high confidence rating because a large number of anima1
both sexes were tested in four dose groups, with a large number of controls. IV
effects were monitored and a dose-related increase in severity was observed. T
data base is rated medium to low because only a few studies support the NOAEL
Medium confidence in the RfD follows.
6. DOCUMENTATION AND REVIEW
U.S. EPA. Drinking Water Criteria Document for Methylene Chloride. Office of
Drinking Water, Washington, DC. (1985)(Draft)
The ADI has been reviewed by the U.S. EPA's ADI (RfD) Work Group."
Agency RfD Work Group Review: 06/24/85,07/08/85, 11/06/85
Verification Date: 11/06/85
7. U.S. EPA CONTACTS
Primary: K. Khanna FTS/382-7588 or 202/382-7588
Office of Drinking Water
Secondary: M.L. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Methylene Chloride
CAS No.: 75-09-2
Information is not available at this time.
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OSWER Directive 9481.00-11
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Methylene Chloride (dichloromethane)
CAS No.: 75-09-2 Preparation Date: 05/21/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification: B2, probable human carcinogen; based on inadequate data in
humans and increased cancer incidence in rats and mice.
1. HUMAN DATA
Inadequate. Neither of two studies of chemical factory workers showed an
excess of cancers (Friedlanderetal., 1978,1985; Ottetal., 1983). In the former
study, exposures were low, but the data provide some suggestion of an increased
incidence of pancreatic tumors. The latter report was designed to examine
cardiovascular effects, and the study period was tooshort to allow for latency of
site-specific cancers.
2. ANIMAL DATA
Sufficient. In a 2-year study (National Coffee Association, 1982,1983) F344 rats
received 0, 5, 50,125 or 250 mg dichloromethane/kg/day in drinking water. B6C3FI
mice consumed 0, 60,125,185or 250 mg/kg/day in water. Female rats responded
with increased incidence of neoplastic nodules or hepatocellular carcinomas, which
was significant by comparison to matched but not to historical controls. Male rats
did not show an increased incidence of liver tumors. Male mice had elevated
incidences of combined neo-plastic nodules and hepatocellular carcinomas, but
female mice did not. This increase was not statistically significant or dose-related.
An NTP (1982) gavage study of rats and mice has not been published because of
data discrepancies.
Inhalation exposure of male and female Syrian hamsters to 0, 500,1500 or
3500 ppm dichloromethane for 6 hours/day, 5 days/week for 2 years did not produce
neoplasia. Female Sprague-Dawley rats exposed under the same conditions
experienced reduced survival at the highest dose. Increased incidences of mammary
tumors were noted in both males and females. Male rats also developed salivary
gland sarcomas (Burek et al., 1984). There is a question as to whether these doses
were at or near the MTD. In a subsequent study (Burek etal., 1984) male and female
rats were exposed to 0, 50, 200 or 500 ppm dichloromethane. No salivary tumors
were observed, but the highest dose resulted in mammary tumors.
Groups of 50 each male and female F344/N rats and B6C3FI mice were exposed
to dichloromethane 6 hours/day, 5 days/week for 2 years. Exposure concentrations
were 0, 1000, 2000 or 4000 ppm for rats and 0, 2000 or 4000 ppm for mice. Survival
of male rats was low, but apparently not treatment related; survival was decreased
in a treatment-related fashion for male and female mice and female rats.
Mammary adenomas and fibroadenomas were increased in male and female rats as
were mononuclear cell leukemias in female rats. Among treated mice of both sexes
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OSWER Directive 9481 00-11
there were increased incidences of hepatocellular adenomas and carcinomas and
highly significant increases in alveolar/bronchiolar adenomas and carcinomas (NTP,
1986).
Two inhalation assays using dogs, rabbits, guinea pigs and rats were negative,
but were not carried out for the lifetime of the animals (Heppel et al., 1944;
MacEwen etal., 1972). Theissetal. (1977) injected strain A male mice
intraperitoneallywithO, 160,400 or 800 mg/kg for 16-17 times. Pulmonary
adenomas were found, but survival of animals was poor.
3. SUPPORTING DATA
Dichloromethane is mutagenic for Salmonella typhimurium with or without
added hepatic enzymes (Green, 1983) and produced mitotic recombination in yeast
(Callen et al., 1980). Results in cultured mammalian cells have generally been
negative, but dichloromethane has been shown to transform rat embryo cells and
to enhance viral transformation of Syrian hamster embryo cells (Price et al., 1978;
Hatch etal., 1983).
B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 7.5 E-3/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/L)
5E + 2ug/L 5E +1 ug/L 5 ug/L 2.1E-7 LM, extra
risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Mouse/B6C3F1,
female; hepato-
cellular
adenomas or
carcinomas
Route: Inhalation
ppm mg/kg/day
0 0
2000 1582
4000 3162
NTP, 1986
mg/kg/day
0
122
244
3/50
16/48
40/48
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OSWER Directi ve 9481.00-1
Mouse/B6C3F1, Route: Water National
male; hepato- Coffee
cellular car- mg/kg/day mg/kg/day Association,
cinomasor 1983
adenomas 0
60
125
185 -
250
0
4.5
9.4
14.0
18.9
24/125
51/200
30/100
31/99
35/125
3. ADDITIONAL COMMENTS
Dichloromethane is rapidly absorbed following either inhalation or ingestion.
Use of inhalation data for calculation of risk is justified if lung tumor data are
excluded. The slope factor is an arithmetic mean of slope factors derived from NTP
(1986) and the National Coffee Association (1983) data (2.6E-3 and 1.2E-2,
respectively). Dose conversions used the mouse assay midpoint weight of 0.032 kg
and estimated inhalation rate of 1.0407 cu.m/day. To obtain estimates of unit risk
for humans, an inhalation rate of 20 cu.m/day was assumed. Dichloromethane was
considered to be a well absorbed vapor at low doses. At the time of publication of
U.S. EPA (1985), no pharmacokinetic or metabolism data were available to justify
modification of the dose assumptions used in the calculation of carcinogenic risk.
The unit risk should not be used if the water concentration exceeds 5E + 4 ug/L,
since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE ESTIMATE
Adequate numbers of animals were used in both assays. Incidences of tumors
in the NTP (1986) bioassay were significantly increased in a dose-related fashion.
Incidences in the National Coffee Association (1983) study were elevated by
comparison to controls (p< 0.05 for the 125,185 and 250 mg/kg/day groups). Risk
estimates based on the more sensitive sex in each study were within a factor of 5.
Confidence is rated medium to high.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
C INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 1.4E-2/mg/kg/day
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OSWER Directive 9481.00-11
1. UNIT RISK SUMMARYTABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
2E + 1 2 2E-1 4.1 E-6 LM, extra
ug/cu.m ug/cu.m ug/cu.m risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Mouse/B6C3F1, Route: Inhalation NTP, 1986
female; combined
carcinomas and ppm mg/kg/day mg/kg/day
adenomas of the
lung or liver 00 0 5/50
2000 5.82 122 36/48
4000 31.64 244 46/47
3. ADDITIONAL COMMENTS
Dose conversions used the mouse assay midpoint weight of 0.032 kg and
estimated inhalation rate of 1.04cu.m/day. To obtain estimates of unit risk for
humans, an inhalation rate of 20 cu.m/day was assumed. Dichloromethane was
considered to be a well absorbed vapor at low doses. There are currently no
pharmacokinetic or metabolism data to justify modification of dose assumption
used in the calculation of carcinogenic risk.
The unit risk should not be used if the air concentration exceeds 2E + 3
ug/cu.m, since above this concentration the slope factor may differ from
that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
Adequate numbers of animals were observed and tumor incidences were
significantly increased in a dose-dependent fashion. Analysis excluding animals
which died before observation of the first tumors produced similar risk estimates as
did time-to-tumor analysis. Risk estimates for both sexes of mice (NTP, 1986) were
within a factor of 2, as the slope factor for male mice was 7.0E-3. Confidence is
rated medium to high.
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OSWER Directive 9481.00-11
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
D. DOCUMENTATION AND REV/EW
1. REFERENCES
U.S. EPA. 1985. Addendum to the Health Assessment Document for
Dichloromethane (methylene chloride). Updated carcinogenicity assessment.
Prepared by the Carcinogen Assessment Group, OHLA, Washington, DC. EPA
600/8-B2/004FF.
NTP (National Toxicology Program). 1986. Toxicology and carcinogenesis studies of
dichloromethane (methylene chloride) in F344/N rats.and B6C3F1 mice (inhalation
studies). NTP-TRS-306.
National Coffee Association. (1983). Twenty-four month oncogenicity study of
methylene chloride in mice. Prepared by Hazelton Laboratories, America Inc.,
Vienna, VA. Unpublished.
2. REVIEW
The Addendum to the Health Assessment Document for Dichloromethane
(methylene chloride) received Agency and external review including a review by the
Science Advisory Board.
Agency WorkGroup Review: 12/04/86
Verification Date: 12/04/86
3. U.S. EPA CONTACTS
Primary: H.Spitzer 202/382-7669 or FTS/382-7669
Office of Research and Development
Secondary: D.Singh 202/382-5898 or FTS/382-5898
Office of Research and Development
III. DRINKING WATER HEALTH ADVISORIES
v
Chemical: -Methylene Chloride
CAS No.: 75-09-2
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OSWER Directive 9481.00-11
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical:
CAS No.:
Methylene Chloride
75-09-2
Preparation Date: 10/16/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
A. RISK MANAGEMENT ACTIONS
Risk
Management
Action
Reportable
Quantity (RQ)
Status
Date
Final
1985
Risk
Management
Value
IOOO Ibs.
Considers
Econ/Tech
Feasibility
no
Reference
50 FR 13456
04/04/85
Water Quality
Criteria (WQC):
a. Human Health
b. Aquatic Toxicity
1) Freshwater
2) Marine
Clean Air Act (CAA)
Regulatory Decision:
Final
1980
Final
1980
Final
1980
0.19ppb no
Acute no
11,000 ug/l
Chronic
none
Acute no
12,000 ug/l
Chronic
6,400 ug/l
45 FR 79318
1/13/80
ibid.
ibid.
B-21
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OSWER Directive 9481.00-11
Nat. Emissions Current Under no FR
Standards for 1935 development 10/17/85
Hazardous Air
Pollutants (NESHAP)
Hazardous Waste Final Listed no 40CFRPart
Constituent 1985 261
(App.VIII) App. VIII
B. RISK MANAGEMENT RATIONALE
RQ
The final adjusted RQ of 1000 pounds is based upon a chronic toxicity score of
10. This substance has recently been identified for assessment of carcinogenicity,
and the RQ will be reevaluated when that assessment is completed.
Contact: RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
WQC
Contact: Office of Water Regulations and Standards
202-382-5400 or FTS-382-5400
a. Human health: Methylene chloride is classified as a carcinogen, and under the
assumption of no threshold for a carcinogen, the recommended WQC is zero.
However, if zero cannot be obtained and exposure is via ingestion of water and
aquatic organisms, 0.19 ug/l is associated with an upper-bound excess lifetime risk
of 1.0E-6 [other risk levels to consider: 1.0E-5 (19 ug/l) and 1.0E-7 (0.019 ug/l)]. If
exposure is only via inqestion of aquatic organisms, the WQC associated with an
upper-bound excess lifetime risk of 1 .OE-6 is 15.7 ug/l. The criteria are based on
halomethanes as a class.
b. Aquatic toxicity: Water quality criteria for the protection of aquatic life are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The "(LEL)" after the value indicates that the minimum data were not
available and the concentration given is not a criteria value but the lowest effect
level found in the literature. The values are based on halomethanes as a class - no
specific chemicals are cited.
V. SUPPLEMENTARY DATA
Chemical: Methylene Chloride
CAS No.: 75-09-2
Information is not available at this time.
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OSWER Directive 9481.00-11
Synonyms. Methane dichloro- (8CI9CI); Aerothene MM; Chlorure de methylene
iFu -L; D'M'?,,rrT;ethaun' uvaso1' Dichloromethane; DCM; Freon 30 Methane
- bjch|oride; Methylene chloride (ACN);
8-23
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OSWER Directive 9481.00-11
REFERENCES FOR METHYLENE CHLORIDE
EPA (U.S. Environmental Protection Agency), 1979. Water-Related Environmental
Fate of 129 Priority Pollutants. EPA/440-4-79-029, Washington, D.C, December
Other Resource Documents
American Conference of Governmental Industrial Hygienists, 1980. Documentation
of the Threshold Limit Values, 4th ed. Cincinnati, Ohio, 1980,488 pp.
Burek, J.D., Nitschke, K.D., Bell, T.J., Wackerle, D.L, Childs, R.C., Beyer, J.E.,
Dittenber, D.A., Rampy, L.W., and McKenna, M.J. "Methylene chloride: A two-
year inhalation toxicity and oncogenicity study in rats and hamsters,"
Fundamentals of Applied Toxicology. 4:30-47.1984.
McCoy and Associates, "Physical/Chemical Data Compendium for Common
Solvents," The Hazardous Waste Consultant Vol. 4, No. 6, Nov./Dec, 1986, pp.
4-1 to 4-32.
National Institute for Occupational Safety and Health, Criteria for a Recommended
Standard—Occupational Exposure to Methylene Chloride, DHEW Publication
No. (NIOSH) 76-138, Washington, D.C., March 1976.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances-Data Base, Washington, D.C., 1983.
National Toxicology Program, NTP Technical Report on the Toxicology and
Carcinoqenesis Studies of Methylene Chloride (CAS No. 75-09- 2) in F344/N
Rats and 86C3F1 Mice (Inhalation Studies). NTP Technical Report No. 291,
USDHHS (NIH) Publication No. 85-2562, Research Triangle Park, North Carolina,
1984.
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OSWER Directive 9481.00-11
SAX, N.I., Dangerous Properties of Industrial Materials. 4th ed. Van Nostrand
ReinholdCo., NewYork, 1975,1,258pp.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Halomethanes, EPA440/5-80-Q51, Office of Water Regulations and Standards,
Criteria and Standards Divisions, Washington, D.C, October 1980.
U.S. Environmental Protection Agency, Health Assessment Document for
Chloroform, EPA 600/8-84-004F, Office of Health and Environmental
Assessment, Washington, D.C., September, 1985.
U.S. Environmental Protection Agency, Health Effects Assessment for Methvlene
Chloride. ECAO-CIN-HO-28 (Final Draft), Environmental Criteria and
Assessment Off ice, Cincinnati, Ohio, September 1984.
Weast, R.E., ed., Handbook of Chemistry and Physics, 62nd ed, CRC Press,
Cleveland, Ohio, 1981,2,332 pp.
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OSWER Directive 9481 00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
TOLUENE
Summary
CAS Number: 108-8&-3
RfD: 0.3 mg/kg/day
Chemical Formula: CeHsCHs
lUPACName: Methylbenzene
Important Synonyms and Trade Names: Toluol, phenylmethane, methylbenzene
Chemical and Physical Properties
MolecularWeight: 92.13
Boiling Point: 110.6°C
Melting Point; -95°C
Specific Gravity: 0.8669 at 20°C
Solubility in Water: 534.8 mg/liter
Solubility in Organics: Soluble in acetone, ligroin, and carbon disulfide;
miscible with alcohol, ether, benzene, chloroform,
glacial acetic acid, and other organic solvents
Vapor Pressure: 28.7 mm Hg at 25°C
Vapor Density: 3.14
Viscosity: 0.625 centipoise at 15.6°C
Flash Point: 4.4°C
Log Octanol/Water Partition Coefficient: 2.69
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OSWER Directive 9481.00-11
Transport and Fate
Volatilization appears to be the major route of removal of toluene from
aquatic environments, and atmospheric reactions of toluene probably subordinate
all other fate processes (EPA, 1979)._ Photooxidation is the primary atmospheric fate
process for toluene, and benzaldehyde is reported to be the principal organic
product. Subsequent precipitation or dry deposition can deposit toluene and its
oxidation products into aquatic and terrestrial systems. Direct photolytic cleavage
of toluene is energetically improbable in the troposphere, and oxidation and
hydrolysis are probably not important as aquatic fates.
The log octanol/water partition coefficient of toluene indicates that sorption
processes may be significant. However, no specific environmental sorption
processes may be significant However, no specific environmental sorption studies
are available, and the extent to which adsorption by sedimentary and suspended
organic material may interfere with volatilization is unknown. Bioaccumulation is
probably not an important environmental fate process. Although toluene is known
to be degraded by microorganisms and can be detoxified and excreted by mammals,
the available data do not allow estimation of the relative importance of
biodegradation/biotransformation processes. Almost all toluene discharged to the
environment by industry is in the form of atmospheric emissions.
Standards and Criteria
Ambient Water Quality Criteria (U.S. EPA):
Aquatic Life
The available data are not adequate for establishing criteria. However, EPA
did report the lowest concentrations of toluene known to be toxic in aquatic
organisms, also known as the lowest effect level (LEL).
Freshwater
Acute toxicity: 17,500 ug/liter (LEL)
Chronic toxicity: No available data
Marine
Acute toxicity: 6,300 ug/liter (LEL)
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OSWER Directive 9481.00-11
Chronic toxicity:
Human Health
Water and Fish Ingestion:
Fish Ingestion Only:
5,000 ug/liter(LEL)
14.3 mg/liter
424.0 mg/liter
Others
NIOSH Recommended Standards: 375 mg/m3 TWA
560mg/m3STEL
OSHA Standards:
750 mg/m3 TWA
1,120 mg/m3 Ceiling Level
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS): Chemical Files
Toluene; CAS No. 108-88-3 (Revised 11/16/1986)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic tpxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.*
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. Fora
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4. :
STATUS OF DATA FOR Toluene
I. Chronic Systemic Toxicity: Noncarcinogenic Health Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: none
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such as carcinogenicity. The RfD is considered to be the level unlikely to
cause significant adverse health effects associated with a threshold mechanism of
action in humans exposed for a lifetime. RfDs can also be derived for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9481.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Toluene
CAS No.: 108-88-3 ' Preparation Date: 01/08/86
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Clinical chemistry 300 ppm (1130 mg/cu. 100 1 3E-1
and hematological m) converted to 29 mg/kg/day
parameters mg/kg/day (NOAEL)
Rat chronic inha- LOAEL: None
lation study
CUT (1980)
* Dose Conversion Factors & Assumptions: 5 days/7 .days, 6 hour/24 hour;
0.5 absorption factor, 20 cu. m human breathing rate; 70 kg; thus, 1130
mg/cu. m x 5 day/7 days x 6 hours/24 hours x 0.5 x 20 cu. m/day / 70 kg =
28.8 mg/kg/day
2. PRINCIPAL AND SUPPORTING STUDIES
CUT (Chemical Industry Institute of Toxicology). 1980. A 24-month inhalation
toxicology study in Fischer-344 rats exposed to atmospheric toluene. CUT, Research
Triangle Park, NC.
Toluene is most likely a potential source of respiratory hazard. The only
chronic toxicity study on toluene was conducted for 24 months in male and female
F344 rats (CUT, 1980). Toluene was administered by inhalation at 30, 100 or 300
ppm (113, 377 or 1130 mg/cu. m)to 120 male and 120 female F344 rats for 6
hours/day, 5 days/week. The same number of animals (120 males and 120 females)
was used as a control. Clinical chemistry, hematology and urinalysis testing was
conducted at 18 and 24 months. All parameters measured at the termination of the
study were normal except for a dose-related reduction in hematocrit values in
females exposed to 100 and 300 ppm toluene.
Based on these findings, a NOAEL of 300 ppm or 1130 mg/cu. m was derived.
An oral RfD of 20 mg/day can be derived using route-to-route extrapolation. This
was done by expanding the exposure from 5 hours/day, 5 days/week to continuous
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OSWER Directive 9481.00-11
exposure and multiplying by 20 cu. m/day and 0.5 to reflect a 50% absorption
factor.
3. UNCERTAINTY AND MODIFYING FACTORS
UF s 100. An uncertainty factor of ,100 (10 for sensitive individuals and 10 for
intraspecies extrapolation was alsaapplied.
MF = 1
4. ADDITIONAL COMMENTS
The only oral study found in the data base (Wolf etal., 1956) contains
subchronic data in which no adverse effects of toluene were reported at the highest
dose tested (590 mg/kg/day).
5. CONFIDENCE IN THE RfD
Study: High Data Base: Medium RfD: Medium.
Confidence in the critical study is high because a large number of animals/sex
were tested in each of three dose groups and many parameters were studied.
Interim kills were performed. The data base is rated medium because several
studies support the chosen effect level. The confidence of the RfD is not higher than
medium because the critical study was by the inhalation route.
6. DOCUMENTATION AND REVIEW
Limited Peer Review and Agency-wide Internal Review, 1984.
U.S. EPA. 1985. Drinking Water Criteria Document for Toluene. Office of
Drinking Water, Washington, DC.
Agency RfD Work Group Review: 05/20/85, 08/05/85,08/05/86
Verification Date: 05/20/85
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OSWER Directive 9481.00-11
7. U.S. EPA CONTACTS
Primary: C.T. DeRosa FTS/684-7534 or 513/569-7534
Office of Research and Development
Secondary: M.L. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Toluene
CAS No.: 108-88-3
This chemical has not been evaluated by the U.S. EPA for evidence of human
carcinogenic potential.
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical: Toluene
CAS No.: 108-88-3 Preparation Date: 09/30/86
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
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OSWER Directive 9481.00-11
note that some risk management decisions consider factors not related to health
risk such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
A. RISK MANAGEMENT ACTIONS
Risk
Management
Action
Reportable
Quantity (RQ)
Status
Date
Final
1985
Risk
Management
Value
1000 I bs
Considers
Econ/Tech
Feasibility
no
Reference
50 FR 13456
04/04/85
Water Quality
Criteria (WQC):
a. Human Health
b. Aquatic Toxicity
1) Freshwater
2) Marine
Clean Air Act
Regulatory
Decision:
(NESHAPorNSPS)
Final
1980
Final
1980
Final
1980
Final
1984
14.3mg/l
no
Acute no
17,500 ug/l(LEL)
Chronic
none
Acute no
6,300 ug/l (LED
Chronic
5,000 ug/l (LEL)
Decision not no
to Regulate
45 FR 79318
11/28/80
ibid.
ibid.
49 FR 22195
05/25/84
B. RISK MANAGEMENT RATIONALE
RQ
The final RQ is based on aquatic toxicity, as established under Section 311(b)(4)
of the Clean Water Act, ignitability and chronic toxicity. Available data indicate
that the aquatic 96-Hour Median Threshold Limit for Toluene is between 10 and 100
ppm. Its dosed cap flash point is less than 100 degrees F and its boiling point is
greater than 100 degrees F. RQ assignments based on chronic toxicity reflect two
primary attributes of the hazardous substance, the minimum effective dose (MED)
levels for chronic exposure (mg/day for 70-kg man) and the type of effect (liver
necrosis, teratogenicity, etc). In accordance with the methodology described in the
Agency's "Technical Background Document to Support Rulemaking Pursuant to
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OSWER Directive 9481.00-11
CERCLA Section 102, Volume 1" of March 1985 and 50 FR 13468 (04/04/85), a
composite score is determined from an evaluation of these two attributes. Toluene
was determined to have a composite score between 6 and 20, corresponding to a
chronictoxicity RQof 1000 pounds.
Contact: RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
WQC
Contact: Office of Water Regulations and Standards
202-382-5400 orFTS-382-5400
a. Human health: The WQC of 14.3 mg/l is based on consumption of
contaminated aquatic organisms and water. A WQC of 424 mg/l has also been
established based on consumption of contaminated aquatic organisms alone.
b. Aquatic toxicity: Water Quality criteria for the protection of aquatic life are
derived from a minimum data base of acute and chronic tests on a variety of aquatic
organisms. The "(LED" after the value indicates that the minimum data were not
available and the concentration given is not a criteria value but the lowest effect
level found in the literature.
CAA Regulatory Decision
EPA concluded that current information does not indicate that toluene
endangers public health at ambient concentrations (excluding emergency releases),
and thus no regulation directed specifically at toluene is necessary at this time
under the CAA.
Contact: Chief, Pollutant Assessment Branch
FTS/629-5645 or 919/541-5645
V. SUPPLEMENTARY DATA
Chemical: Toluene
CAS No.: 108-88-3
Information is not available at this time.
Synonyms: ANTISALIa, METHYL-BENZENE, METHACIDE, PHENYL-METHANE,
METHYLBENZENE, METHYLBENZOL, NCI-C07272, PHENYLMETHANE, RCRA WASTE
NUMBER U220, TOLUEEN (Dutch), TOLUEN (Czech), TOLUENE , TOLUOL, TOLUOLO
(Italian), TOLU-SOL, UN 1294
8-34
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OSWER Directive 9481.00-11
pcnrpFMrFS FOR TOLUENE
EPA (U.S. Environmental Protection Agency), 1979 Water-RelatedEnvironmental
Fate of 129 Priority Pollutants, EPA/440-4-79-029, Washington, D.C.,
December.
Other Resource Documents
American Conference of Governmental Industrial Hygienists, Documentation
of the Threshold Limit Values. 4th ed., Cincinnati, Ohio, 488 pp., 1980.
McCoy and Associates, "Physical/Chemical Data Compendium for Common
Solvents/' The Hazardous Waste Consultant, Vol. 4, No. 6, Nov./Dec., 1986, pp.
4-1 to 4-32.
National Institute for Occupational Safety and Health, Criteria for a Recommended
Standard-Occupational Exposure to Toluene. DHEW Publication No. (NIOSH)
HSM 73-11023, Washington, D.C., 1983.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of
Chemical Substances—Data Base, Washington, D.C., October 1983.
National Research Council, The Alky! Benzenes, National Academy Press,
Washington, D.C., 1980.
Sax, N. I., Dangerous Properties of Industrial Materials, 4th ed.. Van Nostrand
ReinholdCo.,NewYork, 1975,1,258pp.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Toluene. EPA/440-5-80-075. Office of Water Regulations and Standards,
Criteria and Standards Division, Washington, D.C., October, 1980.
U.S. Environmental Protection Agency, Health Effects Assessment for Toluene. Final
Draft, ECAO-CIN-HO-03, Environmental Criteria and Assessment Office,
Cincinnati, Ohio, September 1984.
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OSWER Directive 9481.00-11
Weast, R. E.. ed., Handbook of Chemistry and Physics, 62nd ed CRC Press,
Cleveland, Ohio, 1981, 2,332 pp.
B-36
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OSWER Directive 9481.00-11
CHEMICAL AND PHYSICAL PROPERTIES OF
1. .2-TRICHLORETHANE
Summary
CAS Number: 79-00-5 -
Chemical Formula: CH2CICHCl2
IUPAC Name: 1,1,2-frichloroethane
Important Synonyms and Trade Names: Vinyl trichloride, ethane trichloride
Chemical and Physical Properties
MolecularWeight: 133.41
Boiling Point: 133.8°C
Melting Point: -36.5UC
Specific Gravity: 1.4397 at 20°C
Solubility in Water: 4,5000 mg/liter at 20°C
Solubility in Organics: Soluble in alcohol, ether, and chloroform
Log Octa no I/Water Partition Coefficient: 2.17
Vapor Pressure: 19mmHgat20°C
Vapor Density: 4.63
Flash Point: Not Flammable
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OSWER Directive 9481.00-11
Transport and Fate
Volatilization and subsequent photooxidation in the troposphere are
probably the primary transport and fate processes for 1,1,2-trichloroethane. Some
sorption, bioaccumulatioh, and biodegradation may occur, but these processes are
probably not very important processes for trichloroethane transport or fate.
Standards and Criteria
Rfd (EPA, 1986):
0.2(mg/kg/day)-i
Ambient Water Quality Criteria (U.S. EPA):
Aquatic Life
The available data are not adequate for establishing criteria. However, EPA
did report the lowest concentration known to be toxic to aquatic organisms,
also known as the lowest effect level (LEL).
Freshwater
Acute toxicity:
Chronic toxicity:
No available data
9.4mg/liter(LEL)
Saltwater
Acute toxicity:
Chronic toxicity:
Human Health
Water and Fish Ingestion:
Fish Ingestion Only:
No available data
No available data
0.6 ug/liter( 10-6 risk level)
41.8 ug/liter (10-6 risk level)
Others
CAG Unit Risk (USEPA):
5.7x10-2 (mg/kg/day)-i
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OSWER Directive 9481.00-11
INTEGRATED RISK INFORMATION SYSTEM (IRIS):Chemical Files
1,1,2-Trichloroethane; CAS No. 79-00-5 (Revised 09/30/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic toxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR 1,1,2-Trichloroethane
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: available
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Regulatory Actions: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARCINOGENIC HEALTH EFFECTS
INTERPRETATION OF CHRONIC SYSTEMIC TOXICITY DATA
The Reference Dose (RfD) is based on the assumption that thresholds may exist
for certain toxic effects such as cellular necrosis, but may not exist for other toxic
effects such ascarcinogenicity. The RfD is considered to be the I el unlikely to
cause significant adverse health effects associated with a threshc j mechanism of
action in humans exposed for a lifetime. RfDs can also be derivec for the
noncarcinogenic health effects of compounds which are also carcinogens.
Therefore, it is essential to refer to Section II, and other sources as well, for risk
assessment information pertaining to the carcinogenicity of this compound. Please
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OSWER Directive 9431.00-11
refer to the Background Document on the RfD (Appendix A) in Service Code 4 for an
elaboration of these concepts.
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5 Preparation Date: 12/05/85
1. REFERENCE DOSE SUMMARY TABLE
Critical Effect Experimental Doses * UF MF RfD
Organ histopathology NOEL: 92 mg/kg/day 300 1 2E-1
(adjusted to 65.7 mg/kg/day
Rat Subchronic to mg/kg/day for
Chronic Gavage Study treatment schedule)
NCI, 1978 LOAEL: none
* Dose Conversion Factors & Assumptions: Treatment schedule = 5 days/week
2. PRINCIPAL AND SUPPORTING STUDIES
NCI (National Cancer Institute). 1978. Bioassay of 1,1,2-trichloroethane for possible
carcinogenicity. U.S. DHEWTech. Rep. Ser. 74. Publ. No. NIH 78-1324.
Osbprne-Mendel rats (50/sex/group) were administered 1,1,2-trichloroethane
by corn oil gavage 5 days/week at dose levels of 46 and 92 mg/kg/day for 78 weeks.
Both untreated and vehicle controls were empjoyed (20/sex/group). Extensive
histopathology was performed after 78 weeks. No treatment-related non-
neoplastic lesions were observed. A mouse oncogenic bioassay was also conducted,
with no noncarcinogenic effects observed at doses of 195 and 390 mg/kg/day.
An unpublished inhalation study with several species (Dow Chemical Co.)
showed unspecified fatty changes for female rats at 164mg/cu.m after 3 weeks of
exposure. No effects were observed at an exposure level of 82 mg/cu.m for 7
hours/day, 5 days/week for 6 months. Equivalent oral doselevels were about 6 and
12 mg/kg/day. The effects seen cannot be judged as to adversity.
The NCI (1978) rat study NOEL is more appropriate as a basis for the RfD than
the mouse NOEL because higher doses have not been administered to rats, and the
inhalation studies suggest that the rat may be more sensitive than other species to
the effects of this compound.
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3. UNCERTAINTY AND MODIFYING FACTORS
UF = 300. The UF includes the standard uncertainty factors for interspedes and
intrahuman variability and a factor of 3 for extrapolation to lifetime exposure from
an intermediate exposure duration.
MF = 1 -:
4. ADDITIONAL COMMENTS
None.
5. CONFIDENCE IN THE RfD
Study: Medium Data Base: Low RfD: Low
The critical study is given a medium confidence for balanced strengths
(histopathology) and weaknesses (lack of other parameters). The supporting data
base is meager. The RfD is rated low because of the general lack of appropriate
toxicologicdata.
6. DOCUMENTATION AND REVIEW
The RfD is not currently documented elsewhere, but the studies discussed are
reviewed in: U.S. EPA. 1980. Ambient Water Quality Criteria for Chlorinated
Ethanes. Prepared by the Office of Health and Environmental Assessment,
Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of
Water Regulations and Standards, Washington, DC. EPA 440/5-80-029. NTIS PB 81-
117400.
Agency RfD Work Group Review: 12/18/85,05/15/86
Verification Date: 12/18/85
7. U.S. EPA CONTACTS
Primary: M.L. Dourson FTS/684-7544 or 513/569-7544
Office of Research and Development
Secondary: C.T. DeRosa FTS/684-7534 or 513/569-7534
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B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5
Information is not available at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5 Preparation Date: 02/18/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification:C, possible human carcinogen, based on hepatocellular carcinomas
and pheochromocytomas in one strain of mice. Carcinogenicity was not shown jn
rats. Structurally related to 1,2-dichloroethane, a probable human carcinogen.
1. HUM AN DATA
None.
2. ANIMAL DATA
In a bioassay conducted by NCI (1978) technical grade (92.7% pure) 1,1,2-
trichloroethane was given in corn oil to 50 each male and female Osborne-Mendel
rats and B6C3F1 mice. Administration was 5 times/week for 78 weeks during which
timedosesfor rats were increased from 70 and 30 mg/kg/day to 100 and 50
mg/kg/day; doses for mice were increased from 300 and150 mg/kg/day to 400 and
200 mg/kg/day. By two statistical tests, treatment of mice was found to be
associated with increased incidence of hepatocellular carcinomas. A dose-related
increase in pheochromocytomas was also confirmed in female mice. Tumors found
in treated but not control rats included adrenal cortical carcinomas, transitional-cell
carcinomas of kidney, renal tubular adenomas and hemangiosarcomas of spleen,
pancreas, abdomen and subcutaneous tissue. There was, however, no statistically
significant increase in incidence as a function of treatment.
3. SUPPORTING DATA
1,1,2-Trichloroethane was found to be nonmutagenic for Salmonella
typhimurium (Simmon etal., 1977). In rats and mice acutely exposed to 1,1,2-
trichloroethane by inhalation and intraperitpneal injection, trichloroacetic acid,
trichloroethanol, chloroacetic acid and thiodiacetic acid were among the urinary
metabolites identified (Yllner, 1971; Ikeda and Ohtsuji, 1972). 1,1,2-
Trichloroethane is structurally related to 1,2-dichloroethane, a probable human
carcinogen.
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B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 5.7E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE *
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/L)
6E1 ug/L 6 ug/L 6E-1 ug/L 1.6E-6 LM, extra
risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Mouse/B6C3F1, Route: Oral, gavage
male; hepato-
cellular carcinoma mg/kg/day mg/kg/day
0 0 2/20 NCI, 1978
139 9.3 18/49
279 18.6 37/49
3. ADDITIONAL COMMENTS
Doses are TWAs adjusted for frequency of exposure (5/7 days). Weight of the
mice was assumed to be 0.033 kg.
The unit risk should not be used if the water concentration exceeds 6E + 3 ug/L,
since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE ESTIMATE
Dose-related increases in hepatocellular carcinomas were observed in
adequate numbers of mice of both sexes. Modeling was done on only one data set.
Background incidence of this tumor type is generally high. Confidence in the risk
estimate is rated low to medium.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
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Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
C. INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 5.7E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
6ug/cu.m 6E-1 ug/cu.m 6E-2 ug/cu.m 1.6E-5 LM, extra
risk
2. DOSE-RESPONSE DATA
The inhalation risk estimates were calculated from the oral exposure data.
3. ADDITIONAL COMMENTS
The unit risk should not be used if the air concentration exceeds 6E + 2
ug/cu.m, since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
Confidence in this inhalation risk estimate based on oral data is rated low.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
D. DOCUMENTATION AND REVIEW
1. REFERENCES
NCI (National Cancer Institute). 1978. Bioassayof 1,1,2,-Trichloroethane for
Possible Carcinogenicity. U.S. Dept. Health, Educ. Welf. Pub. No. NCi-CG-TR-74.
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US EPA 1980. Ambient Water Quality Criteria for Chlorinated Ethanes. Prepared
by the Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Cincinnati, OH for the Office of Water Regulations and
Standards, Washington, DC. EPA 440/5-80-029. NTIS PB 81117400.
2. REVIEW:
The values in the Ambient Water Quality Criteria Document for Chlorinated
Ethanes received extensive peer and public review.
Agency Work Group Review: 07/23/86
Verification Date: 07/23/86
3. U.S. EPA CONTACTS
Primary: C. Hiremath 202/382-5725 or FTS/382-5725
Office of Research and Development
Secondary: R.E. McGaughy 202/382-5898 or FTS/382-5898
III. DRINKING WATER HEALTH ADVISORIES
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5
Information is not available at this time.
IV. REGULATORY ACTIONS
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5 Preparation Date: 09/30/87
INTERPRETATION OF REGULATORY ACTION INFORMATION
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Regulatory actions are frequently not
updated at the same time. Carefully read the dates for the regulatory actions (in
this section) and the verification dates for the risk assessments(in sections I & II), as
this may explain apparent inconsistencies. Also note that some regulatory actions
consider factors not related to health risk, such as technical or economic feasibility.
Such considerations are indicated for each action following (Econ/Tech Feasibility
entry). In addition, not all of the regulatory actions listed in this section involve
enforceable federal standards. Please direct any questions you may have
concerning the use of risk assessment information, in making a regulatory decision
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OSWER Directive 9481.00-11
to the U.S. EPA contact listed for that particular regulatory action. Users are
strongly urged to read the background information on each regulatory action in
Appendix D in Service Code 4.
A. AIR
Information is not available at this time.
B. WATER
Information is not available at this time.
C. TOXICS/PESTICIDES
Information is not available at this time.
D. SUPERFUND / RESOURCE CONSERVATION AND RECOVERY ACT (RCRA)
REPORTABLE QUANTITY (RQ); for Release into the Environment
Value (status)-- 100 pounds (Proposed, 1987)
Considers technological or economic feasibility? -- NO
Discussion -- The proposed RQ for 1,1,2-trichlproethane is 100 pounds, based on
potential carcinogenicity. The available data indicate a hazard ranking of "low,"
based on a potency factor of 0.36 (mg/kg/day)-1 and weight-of-evidence group "C,'
which corresponds to an RQ of 100 pounds.
Reference --
U.S. EPA Contact -- RCRA/Superfund Hotline
800-424-9346 or 382-3000 (202 area/FTS)
V. SUPPLEMENTARY DATA
Chemical: 1,1,2-Trichloroethane
CAS No.: 79-00-5
Information is not available at this time.
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SYNONYMS: ETHANE, 1,1,2-TRICHLORO-; ETHANE TRICHLORIDE; NCI-C04579;
RCRA WASTE NUMBER U227; RCRA WASTE NUMBER U359; beta-T; beta-
TRICHLOROETHANE; 1,1,2-TRICHLORETHANE; 1,1,2-TRICHLOROETHANE; 1,2,2-
TRICHLOROETHANE; 1,1,2-TRICHLOROETHANE (ACGIH); TROJCHLOROETAN(1,1,2)
(Polish); VINYL TRICHLORIDE
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REFERENCES FOR 1,1,2-TRlCHLOROETHANE
EPA (U.S. Environmental Protection Agency), 1986. Research and Development.
Verified Reference Doses (RfDs) of the U.S. EPA. ECAO-CIN-475, Environmental
Criteria and Assessment Office, Cincinnati, Ohio, January.
Other Resource Documents
International Agency for Research on Cancer, "Some Halogenated Hydrocarbons,"
IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to
Humans. Vol. 20, World Health Organization, Lyon, France, pp 545-572.
National Cancer Institute, Bioassavof 1,1,2-Trichloroethane for Possible
Carcinoqenicity, NCI Carcinogenesis Technical Report Series No. 74, DHEW
Publication No. (NIH) 78-1324,1977.
National Institute for Occupational Safety and Health (NIOSH), Registry of
Toxic Effects of Chemical Substances-Data Base. Washington, D.C., October
1983.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Chlorinated Ethanes. EPA/440-5-80-029, Office of Water Regulations and
Standards, Criteria and Standards Division, Washington, D.C., October, 1980.
U.S. Environmental Protection Agency, Health Assessment Document for
Dichloromethane (Methylene Chloride). EPA/600-8-82-004F, Office of Health
and Environmental Assessment, Washington, D.C., February 1985.
U.S. Environmental Protection Agency, Health Effects Assessment for 1, 1,2,-
Trichloroethane. ECAO-CIN-HO-045, Environmental Criteria and Assessment
Office, Cincinnati, Ohio, September 1984.
U.S. Environmental Protection Agency. Water-Related Environmental Fate of 129
Priority Pollutants, EPA/440-4-79-029, Washington, D.C., December, 1979.
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Verschueren, K., Handbook of Environmental Data on Organic Chemicals,
VanNostrand Reinhold Co., New York, 1977,656pp.
Weast, R.E., ed.. Handbook of rhgrnistrv and Physics. 62nd ed.. CRC
Press, Cleveland, Ohio, 1981 2,332pp.
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CHEMICAL AND PHYSICAL PROPERTIES OF
TRICHLOROETHYLENE
CAS Number: 79-01-6
Chemical Formula: C2HC13'"
ILJPACName: Trichlp'roethene
Important Synonyms and Trade Names: Trichloroethene, TCE, and ethylene
trichloride
Chemical and Physical Properties
Molecular Weight: 131.5
Boiling Point: 87°C
Melting Point: -73°C
Specific Gravity: 1.4642 at 20°C
Solubility in Water: 1,000 mg/liter
Solubility in Organics: Soluble in alcohol, ether, acetone, and chloroform
Henry's Law Constent: 8.92 x 10-3 atm-m3/mole at 25°C
Vapor Pressure: 60 mm Hg at 20°C
Vapor Density: 4.53
Viscosity: 0.610 centipoise at 15.68C
Flash Point: 32°C (closed cup)
Log Octanol/Water Partition Coefficient: 2.29
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Transport and Fate
Trichloroethylene (TCE) rapidly volatilizes into the atmosphere where it reacts
with hydroxyl radicals to produce hydrochloric acid, carbon monoxide, carbon
dioxide, and carboxylic acide. This is probably the most important transport and
fate process for trichloroethylene in surface water and in the upper layer of soil. TCE
adsorbs to organic materials and*can be bioaccumulated to some degree. However,
it is unclear whether trichloroethylene bound to organic material can be degraded
by microorganisms or must be desorbed to be destroyed. There is some evidence
that higher organisms can metabolize TCE. Trichloroethylene leaches into the
groundwater fairly readily, and it is a common contaminant of groundwater around
hazardous waste sites.
Standards and Criteria
National Primary Drinking Water Standard:
MCL: 0.005 mg/liter
Ambient Water Quality Criteria (U.S. EPA):
Aquatic Toxicity
The available data are not adequate for establishing criteria. However, EPA
did report the lowest values known to be toxic in aquatic organisms, also
known as the lowest effect level (LEL).
Freshwater
Acute toxicity: 45 mg/liter
Chronic toxicity: 21.9 mg/liter
Marine
Acute toxicity: 2 mg/liter
Chronic toxicity: No available data
Human Health
Water and Fish Ingestion: 2.7 ug/liter (10-6 risk level)
Fish Ingestion Only: 80.7 ug/liter (10-6 risk level)
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Estimates of the carcinogenic risks associated with lifetime exposure to various
concentrations of trichloroethylene in water are:
Risk
Concentration
10-5 27ug/liter
10-6 2.7ug/liter
10-7 0.27ug/liter
Others
CAG Unit Risk (U.S. EPA): 1.1x10-2 (mg/kg/dayH
NIOSH Recommended Standards (air):
OSHA Standards (air):
540 mg/m3 TWA
760 mg/m3 10-min Ceiling Level
540 mg/m3 TWA
1,075 mg/m3/l5-min Ceiling Level
1,620 mg/m3 for 5 min every 3 hr,
Peak Concentration
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INTEGRATED RISK INFORMATION SYSTEM (IRIS):Chemical Files
Trrchloroethylene; CAS No. 79-01-6 (Revised 03/31/87)
USE AND INTERPRETATION OF THE DATA IN IRIS
Health risk assessment information on chemicals is included in IRIS only after a
comprehensive review of chronic tdxicity data by work groups composed of U.S. EPA
scientists from several Agency Program Offices. The summaries presented in
Sections I and II represent a consensus reached in those reviews. The conceptual
bases of these risk assessments are described in Appendices A & B in Service Code 4.
The other sections are supplementary information which may be useful in particular
risk management situations, but have not yet undergone comprehensive U.S. EPA
review. The risk management numbers (Section V) may not be based on the most
current risk assessment, or may be based on a current, but unreviewed, risk
assessment, and may take into account factors other than health effects (e.g.,
treatment technology). When considering the use of risk management numbers for
a particular situation, note the date of their development, the date of the most .
recent risk assessment, and whether technological factors were considered. For a
more detailed description of procedures used in these assessments and the ,.
development of risk management numbers, see Appendix D in Service Code 4.
STATUS OF DATA FOR Trichloroethylene
I. Chronic Systemic Toxicity: Noncarcinogenic Effects
A. Oral RfD: under review
B. Inhalation RfD: none
II. Risk Estimates for Carcinogens: available
III. Drinking Water Health Advisories: none
IV. Risk Management Summaries: available
V. Supplementary Data: none
I. CHRONIC SYSTEMIC TOXICITY: NONCARGNOGENIC HEALTH EFFECTS
A. REFERENCE DOSE (RfD) FOR ORAL EXPOSURE
Chemical: Trichloroethylene
CAS No.: 79-01-6
A risk assessment for this chemical is under review by an EPA workgroup.
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B. REFERENCE DOSE (RfD) FOR INHALATION EXPOSURE
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available.at this time.
II. RISK ESTIMATES FOR CARCINOGENS
Chemical: Trichloroethylene
CAS No.: 79-01-6 Preparation Date: 02/18/87
A. U.S. EPA CLASSIFICATION AND BASIS
Classification: B2, probable human carcinogen; based on positive responses in
two strains of mice by two routes and suggestive increases in tumor
incidences in male rats by gavage. Supporting evidence does not
downgrade the classification. ;
1. HUM AN DATA
Three cohort studies of exposed workers (Axelson, 1978; Tola etal., 1980;
Malek et al., 1979) found no excess cancer risk associated with trichloroethylene
exposure. Results from a case-control study of malignant lyrnphoma cases by
Hardell (1981) were suggestive of an association between trichloroethylene
exposure and malignant lymphoma, but the study had various limitations. Studies
by Novotna etal. (1979) and Paddle (1983) of liver cancer cases found no association
with trichloroethylene exposure. No controls were used in the latter two studies.
2. ANIMAL DATA
Positive evidence of carcinogenicity has generally come from studies of mice.
Negative results have been obtained from gavage treatment of Osborne-Mendel
rats, Sprague-Dawley rats and ICR/Ha Swiss mice (NCI, 1976; Maltoni, 1979;
Henscnler et al., 1984). The NCI (1976) study may be inconclusive due to high
mortality and the Maltoni (1979) exposure was carried out for a less-than-lifetime
period. An NTP(1983) study found a small increase in incidence of renal
adenpcarcinomas in male Fischer 344 rats treated by gavage. This was significant by
statistical tests that took survival differences into account, but not by the
unadjusted Fisher Exact test.
Henschler et al. (1980) found a significant increase in malignant lymphomas in
female Han:NMRI mice exposed by inhalation. The spontaneous incidence of
lymphomas in controls was also high. Inhalation treatment of the following
produced negative results: Charles River rats; Han:Wist rats, Syrian hamsters and
maleHan:NMRI mice (Bell etal., 1978; Henschler etal., 1980).
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Trichloroethylene did not serve as either an initiator or as a complete skin
carcinogen (van Duuren et al., 1979) Trichloroethylene oxide was also negative in
an initiation-promotion assay and after s.c. injection.
Male and female B6C3F1 mice were treated 5 days/week for 78 weeks by corn
oil gavage with epoxide-stabilized trichloroethylene. Doses were TWA were 1169
and 2339 mg/kg for males and 869-and 1739 mg/kg for females.cinomas (NCI, 1976).
A repeat bioassay confirmed the observation of increased incidence of
hepatocellular carcinoma. In this study, male and female B6C3F1 mice were treated
with purified trichloroethylene containing no detectable epoxides by corn oil
gavage of 1000 mg/kg/day, 5 days/week for 103 weeks (NTP, 1983).
3. SUPPORTING DATA
Trichloroethylene of various grades of purity was negative or weakly positive
in mutagenicity assays with S. typhimurium, E. coli and S. pombe. Itwasmutagenic
for both S. cerevisiae and in the mouse spot test. While tests for chromosomal
aberrations were negative,, trichloroethylene produced mitotic recombination in S.
cerevisiae and borderline positive responses in assays of SCE (after occupational
exposure) and unscheduled DNA synthesis. Metabolites of trichloroethylene have
likewise produced variable, largely negative, responses (U.S. EPA, 1985).
Trichloroethylene oxide, however, has been shown to transform Syrian hamster
embryo cells after in vitro exposure (DiPaolo and Doniger, 1982).
B. ORAL QUANTITATIVE ESTIMATE
Slope Factor = 1.1 E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Water Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/L)
3E + 2 ug/L 3E +1 ug/L 3 ug/L 3.2E-7 LM, extra
risk
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2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Slope Reference
Tumor Type Administered Human Equivalent Incidence Factor
Mouse/B6C3F1, Route: Oral, gavage
male and
female;
hepatocellular
carcinomas mg/kg/day
male 0
1000
female 0
1000
male 0
1169
2339
female 0
869
1739
mg/kg/day
0
47.39
0
45.62
0
45.11
85.80
0
31.65
61.43
/mg/kg
/day
8/48 .9E-2 NTP, 1983
30/50
2/49 8.0 E-3
13/49
1/20 1.8E-2 NCI, 1976
26/50
31/48
0/20 5.8E-3
4/50
11/47
3. ADDITIONAL COMMENTS
Metastases to the lungs were observed in one control male and five treated
males in the NTP (1983) study. Survival of treated males was decreased by
comparison with controls. Doses for the NCI (1976) study are TWA. There was little
toxicity in this study not attributed to tumor development. The slope factor used
for the unit risk is the geometric mean of the four slope factors above.
Data on metabolism of gavaged trichloroethylene in Swiss Cox mice (Buben
and O'Flaherty, 1985) suggest that the NTP (1983) gavage assay dose of 1000
mg/kg/day is within the linear portion of the dose/amount metabolized curve; the
high doses of the NCI (1976) bioassay approach the saturation of metabolism.
Human equivalent lifetime average metabolized doses were calculated as follows:
human equivalent dose = weeks treated/weeks observed x 5 days/7 days x
animal metabolized dose in (mg/day) x
(WH/WA)**2/3
where: WH = 70kg
WA = 0.04 kg male mice, 0.035 female mice (NTP, 1983); 0.033
kg male, 0.026 female (NCI, 1976) -
The unit risk should not be used if the water concentration exceeds 3E + 4
ug/L, since above this concentration the slope factor may differ from that
stated.
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4. STATEMENT OF CONFIDENCE IN THE ORAL QUANTITATIVE RISK ESTIMATE
Slope factors for male and female B6C3F1 mice from two independent studies
are very close (all within a factor of 3). Adequate numbers of animals were studied,
and tumor incidences were significantly elevated comparably, although the follow-
up studies had only only one positfve dose group. Confidence in the risk estimate is
rated medium to high.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
C. INHALATION QUANTITATIVE ESTIMATE
Slope Factor = 1.3E-2/mg/kg/day
1. UNIT RISK SUMMARY TABLE
Air Concentrations Producing Risk Levels Unit Risk Model
E-4 E-5 E-6 (/ug/cu.m)
8E1 ug/cu.m 8 ug/cu.m 8E-1 ug/cu.m 1.3E-6 LM, extra
risk
2. DOSE-RESPONSE DATA
Species/Strain Dose Tumor Reference
Tumor Type Administered Human Equivalent Incidence
Calculated from oral data as follows:
Unit risk = 1.3E-2 x9.9E-5
where: 1.3E-2 = slope factor (/mg metabolized dose/kg/day)
9.9E-5 = body metabolite load
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3. ADDITIONAL COMMENTS
Data by Monster etal. (1976) were used as the basis for estimation of the
amount of trichloroethylene metabolized by humans exposed to 1 mg/cu.m. The
mean amount metabolized was 439 mg for four subjects exposed to 70 ppm for 4
hours. The amount of metabolite formed following continuous 24-hour exposure
to 1 ug/cu.m was estimated to be 9.9E-5 mg/kg/day.
The unit risk should not be used if the air concentration exceeds 8E + 3
ug/cu.m, since above this concentration the slope factor may differ from that stated.
4. STATEMENT OF CONFIDENCE IN THE INHALATION QUANTITATIVE ESTIMATE
There are data from metabolism studies on inhalation of trichloroethylene by
human subjects to justify dose assumptions. Confidence in this inhalation risk
estimate derived from oral data is rated medium.
Note: Although the statement of confidence in the quantitative estimate is a
consensus of the Agency Work Group, it is a somewhat subjective judgment. The
Work Group is in the process of reviewing definitions of confidence and improving
the process whereby this judgment is made. Statements of confidence will be
revised as necessary when this process is complete.
D. DOCUMENTATION AND REVIEW
1. REFERENCES
U.S. EPA. 1985. Health Assessment Document for Trichloroethylene. Prepared by
the Office of Health and Environmental Assessment, Environmental Criteria and
Assessment Office, Research Triangle Park, NC. EPA 600/8-82-006F.
NTP (National Toxicology Program). 1983. CarcinogenesisBioassayof
Trichloroethylene (CAS No. 79-01-6). NTP Report No. 81-84. Dept. HHS. Publ. No.
83-1799.
NCI (National Cancer Institute). 1976. Carcinogenicity Bioassay of Trichloroethylene
(CAS No. 79-02-6). Carcinogenesis Technical Report Series No. 2.
2. REVIEW
The 1985 Health Assessment Document for Trichloroethylene received both an
Agency and external review.
Agency Work Group Review: 12/04/86
Verification Date: 12/04/86
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3. U.S. EPA CONTACTS
Primary: R. Bellies 202/382-7436 or FTS/382-7436
Office of Research and Development
Secondary: C.Chen 202/382-5898 or FTS/382-5898
Office of Research7and Development
III. DRINKING WATER HEALTH ADVISORIES
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available at this time.
IV. RISK MANAGEMENT SUMMARIES
Chemical: Trichloroethylene
CAS No.: 79-01-6 Preparation Date: 03/31/87
INTERPRETATION OF RISK MANAGEMENT DATA
EPA risk assessments may be continuously updated as new data are published
and as assessment methodologies evolve. Risk management (RM) decisions are
frequently not updated at the same time. Carefully read the dates for the risk
management actions (in this section) and the verification dates for the risk
assessments (in sections I & II), as this may explain apparent inconsistencies. Also
note that some risk management decisions consider factors not related to health
risk, such as technical or economic feasibility. Such considerations are indicated in
the table below (Considers Econ/Tech Feasibility). Please direct any questions you
may have concerning the use of risk assessment information in making a risk
management decision to the contact listed in Part B of this section (Risk
Management Rationale). Users are strongly urged to read the background
information on each RM action in Appendix E in Service Code 4.
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A. RISK MANAGEMENT ACTIONS
Risk Status Risk Considers
Management Management Econ/Tech
Action Date Value Feasibility Reference
Reportable Proposed 100 Ibs no 52 FR 8140
Quantity (RQ) 1987.-" 03/16/87
Clean Air Act (CAA)
Regulatory Decision:
Nat. Emissions Current Under no 50 FR 52422
Standards for 1985 development 12/23/85
Hazardous Air
Pollutants (NESHAP)
B. RISK MANAGEMENT RATIONALE
A-
RQ >
The proposed RQ fortrichloroethylene is 100 pounds, based on potential
carcinogenicity. The available data indicate a hazard ranking of low, based on a
potency factor of 0.070 (mg/kg/day)-1 and weight-of-evidence classification B2,
which corresponds to an RQ of 100 pounds.
Contact: Office of Emergency and Remedial Response
202/382-2180 or FTS/382-2180
CAA Regulatory Decision
NESHAP: Trichloroethylene (TCE) is a probable human carcingen (EPA Group
82) and according to EPA's preliminary risk assessment from ambient air exposures,
public health risks are significant (4.1 cancer cases per year and maximum lifetime
individual risks of 9.4x10-5). Thus, EPA indicated that it intends to add TCE to the
list of hazardous air pollutants for which it intends to establish emission standards
under section 112(b)(1)(A) of the Clean Air Act. The EPA will decide whether to add
TCE to the list only after studying possible techniques that might be used to control
emissions and further assessing trie public health risks. The EPA will add TCE to the
list if emissions standards are warranted.
Contact: Chief, Pollutant Assessment Branch
FTS/629-5645 or 919/541-5645
V. SUPPLEMENTARY DATA
Chemical: Trichloroethylene
CAS No.: 79-01-6
Information is not available at this time.
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SYNONYMS: ETHYLENE,TRICHLORO-; ACETYLENE TRICHLORIDE; ALGYLEN;
ANAMENTH; BENZINOL; BLACOSOLV; BLANCOSOLV; CECOLENE; CHLORILEN; 1-
CHLORO-2,2-DICHLOROETHYLENE; CHLORYLEA; CHLORYLEN; CHORYLEN;
CIRCOSOLV; CRAWHASPOL; DENSINFLUAT; 1.1-DICHLORO-2-CHLOROETHYLENE;
DOW-TRI; DUKERON; ETHINYLTRICHLORIDE; ETHYLENE TRICHLORIDE; FLECK-FLIP;
FLOCK FLIP; FLUATE; GEMALGENE; GERMALGENE; LANADIN; LETHURIN;
NARCOGEN; NARKOGEN; NARKOSOID; NCI-C04546; NIALK; PERM-A-CHLOR;
PERM-A-CLOR; PETZINOL; PHILEX; RCRA WASTE NUMBER U228; TCE;
THRETHYLEN; THRETHYLENE; TRETHYLENE; TRI; TRIAD; TRIAL; TRIASOL;
TRICHLOORETHEEN (Dutch); TRICHLOORETHYLEEN, TRI (Dutch); TRICHLORAETHEN
(German); TRICHLORAETHYLEN.TRI (German); TRICHLORAN; TRICHLOREN;
TRICHLORETHENE (French); TRICHLORETHYLENE; TRICHLORETHYLENE, TRI
(French); TRICHLOROETHENE; TRICHLOROETHYLENE; 1,1,2-TRICHLOROETHYLENE;
1,2,2-TRICHLOROETHYLENE; TRICHLOROETHYLENE (ACGIH.DOT); TRI-CLENE;
TRICLORETENE (Italian); TRICLOROETILENE (Italian); TRIELENE; TRIELIN; TRIELINA
(Italian); TRIKLONE; TRILEN; TRILENE; TRIUNE; TRIMAR; TRIOL; TRI-PLUS; TRI-PLUS
M; UN 1710 (DOT); VESTROL; VITRAN; WESTROSOL
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RESOURCE DOCUMENTS FOR TRICHLORQETHYLENE
International Agency for Research on Cancer, "Some Halogenated Hydrocarbons,"
IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to
Humans, Vol. 20, World Health Organization, Lyon, France, pp 545-572.
McCoy and Associates, "Physical^Chemical Data Compendium for Common
Solvents," The Hazardous Waste Consultant. Vol. 4, No. 6, Nov./Dec., 1986, pp
4-1 to 4-32.
National Cancer Institute, Bioassay of Trichloroethylene for Possible
Carcinogenicitv. CAS No. 79-01-6, NCI Carcinogenesis Technical Report Series
No. 2, DHEW Publication No. (NIH) 76-802. Washington, D.C, 1976.
National Institute for Occupational Safety and Health, Registry of Toxic Effects of I
Chemical Substances-Data Base. Washington, D.C., October 1983. j
National Toxicology Program, Carcinogenesis Bioassav of Trichloroethylene.
CAS No. 79-01-6, NTP 81-84, NIH Publication No. 82-1799, 1982.
U.S. Environmental Protection Agency, Ambient Water Quality Criteria for
Trichloroethylene. EPA/400-5-80-077, Off ice of Water Regulations and
Standards, Criteria and Standards Division, Washington, D.C., October 1980.
U.S. Environmental Protection Agency, Health Assessment Document for
Trichloroethvlene. Review Draft. EPA/600-8-82-0068, Washington, D.C., 1983.
U.S. Environmental Protection Agency, Water-Related Environmental Fate of 129
Priority Pollutants. EPA 440/4-79-029, Washington, D.C., December 1979.
Verschueren, K., Handbook of Environmental Data on Organic Chemicals,
Van Nostrand Reinhold Co., New York, 1977, 659 p.
Waters, E. M., Gerstner, H.B., and Huff, J.E., "Trichloroethylene: 1. An Overview,"
J. Toxicol. Enivron. Health. 2:674-700.
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Weast, R.E., ed., Handbook of Chemistry and Physics, 62nd ed.. CRC Press,
Cleveland, Ohio, 1981, 2,332 p.
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