^tosr-%
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OCT 25 1993
OFFICE OF
SOLID WASTE AND EMERGENCY
RESPONSE
MEMORANDUM
SUBJECT
FROM:
TO:
OSWER Directive 9360.1-02
Final Guidance on Numeric Removal Action Levels for
Contaminated Drinking Water Sites
Deborah Y. Dietrich, Director
Emergency Response Division
Removal Managers
Regions I - X
Purpose
The purpose of this memorandum is to transmit the final OERR
methodology and guidance on the calculation of numeric removal
action levels (RALs), to assist Superfund personnel in deciding
whether to provide alternate sources of drinking water to
populations adversely affected by releases of hazardous
substances into the environment.
Introduction
RALs are drinking water concentrations of contaminants that
are considered, along with other factors, in determining whether
to provide alternate water supplies under Superfund removal
authority. RALs were established in OSWER (Office of Solid Waste
and Emergency Response) Directive 9360.1-01, Interim Final
Guidance on Removal Action Levels at Contaminated Drinking Water
Sites (October 1987) . That directive defined two types of RALs:
(1) numeric levels for individual substances, which apply
generally across most sites, and (2) site-specific levels, which
are based on a more detailed analysis of conditions at a
particular site and are determined on a case-by-case basis. A
methodology for calculating numeric RALs for drinking water was
presented in the 1987 OSWER directive, and values for 34
substances were listed in Exhibit 2 of that directive. The
Office of Emergency and Remedial Response (OERR)/Emergency
Response Division (ERD) distributed an updated and significantly
expanded table of numeric RALs in April 1991 that listed values -
calculated using the same methodology described in the 1987 OSWER
Directive - for 165 substances.
Recycled/Recyclable
T\
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Obiective
ERD has adopted a new methodology for determining RALs for
contaminated drinking water. This memorandum explains the new
methodology and provides the rationale for adopting it. As
discussed in the next section, the new methodology better matches
the needs of the Superfund removal program and is more consistent
with procedures used by the Office of Water (OW) than the
previous guidance. The attached table lists updated numeric RALs
for 204 substances developed using the new methodology. These
updated RALs supersede the values given in the April 1991 table
distributed by ERD. Regions should begin using the newly updated
RALs immediately, in the same manner as previous values were used
(i.e., as one factor in deciding whether to provide alternate
water supplies under Superfund removal authority). Issuance of
this update of numeric RALs does not in any way restrict the
existing flexibility of a Regional office to develop and apply
site-specific RALs. Note that the updated numeric RALs apply to
new removal starts, and, in general, are not intended to affect
ongoing or completed removal actions.
Implementation
New RAL Methodology: Background and Rationale
ERD has adopted the procedures recently developed by OW for
determining short-term acceptable risk (STAR) levels as the new
methodology for setting numeric RALs for drinking water. The
STAR is one factor, along with cost and affordability
considerations, used in making unreasonable risk to health (URTH)
determinations under the Safe Drinking Water Act. Under the Act,
EPA (or primacy states) may grant a public water system a
variance or exemption from a Maximum Contaminant Level (MCL; for
definition, see box on page 5) if it finds that the variance or
exemption will not result in an URTH.
The STAR is defined as the upper-bound concentration of a
contaminant in drinking water, generally above the MCL (and never
lower than the MCL), that would not pose a health risk for
exposures lasting up to seven years (approximately 10 percent of
an individual's lifetime). As of the date of this memorandum, OW
has released STAR values for 47 chemical substances, all of which
are included in the attached table of updated RALs. In addition,
OW has issued Guidance for Determining Unreasonable Risks to
Health (EPA/OW/Office of Science and Technology, 1992), which
describes in detail the procedures for determining STARs. The
guidance also allows for development of site-specific URTHs,
where appropriate, and lists factors to be considered in their
development.
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ERD adopted the STAR methodology to replace its previous
approach to determining RALs for drinking water primarily for the
following reasons:
As risk-based levels developed specifically for
relatively short-term exposures to individual
contaminants in drinking water, STARs are the Agency
numbers that most closely correspond to the needs of
the Superfund removal program for action levels.
Levels based on exposure periods of up to seven years
are more relevant to removal program decision-making
than levels based on lifetime exposures (as used in the
previous approach). It is important to note, however,
that while the STAR is a level for short-term exposure,
it is derived from numbers (e.g., MCLs and drinking
water equivalent levels (DWELs)) that are protective
over a lifetime of exposure.
STARs are developed using OW procedures and data, which
are extensively reviewed both within the Agency and by
independent scientific groups, including EPA's Science
Advisory Board and the National Academy of Sciences.
In addition, the STAR methodology was subject to public
review and comment as part of its development process.
Problems that potentially could arise from
inconsistencies between RALs and STARs will be avoided,
as EPA will be using the same approach to evaluating
short-term exposures to drinking water contamination in
the Superfund removal program as in the OW drinking
water program.
Thus, the new methodology enhances both the scientific
credibility of RALs and their consistency with OW procedures and
data.
Differences Between the Old and New Methodologies
There are several differences between the newly adopted
methodology and the previous approach to determining RALs,
including: (1) primary reliance on OW data and procedures; (2)
explicit consideration of short-term toxicity data; (3)
elimination of the possibility of a numeric RAL being lower than
the corresponding MCL; and (4) elimination of the two-fold
reduction factor applied to volatile non-carcinogens. The
previously used adjustment factor for volatiles was eliminated
because the OW values and calculation procedures that are the
basis of the new methodology are considered protective of
exposures from inhalation of volatiles released from drinking
water as well as from direct ingestion.
It is important to note that exposure to volatiles other
than through ingestion is receiving much Agency attention. The
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Office of Water is investigating methodologies for assessing
inhalation risks from volatile contaminants (mainly
trihalomethanes) and is scheduled to take action on this issue
this year. What the Office of Water does with trihalomethanes
will have important implications for other volatiles and may lead
to some modifications of the assumptions and methodologies used
to derive STAR levels and other drinking water standards.
Currently, the Office of Water considers the RfD/DWEL, longer-
term health advisory, and cancer risk level protective for
volatile and non-volatile contaminants because exposure from
sources other than drinking water are not factored out of the
risk calculations as they are for the MCL/MCLG. This approach
continues to have the approval of the NAS and SAB. Please keep
in mind that regional personnel may always choose to factor in
inhalation exposure as they would any other site-specific
consideration when deciding to perform a removal action.
In addition, OW's 10-day Health Advisory values are no
longer considered in the RAL process. Although never part of the
actual calculation procedure for numeric RALs, 10-day Health
Advisories were listed in the October 1987 and April 1991 tables
of values, and the October 1987 directive instructed that they be
considered in certain "special cases" (including the case
referred to above, which no longer occurs, when a calculated
numeric RAL was lower than the corresponding MCL). Because 10-
day Health Advisories are developed for much shorter exposure
periods (i.e., 10 days) than is appropriate for many removal site
situations, where exposure to contaminated drinking water may
have occurred over weeks, months, or even years, they are not
considered adequately protective, in general, for application at
removal sites. Moveover, at many rites there is substantial
uncertainty over exactly how long exposures have been occurring.
Therefore, the newly updated RALs, which are based on a more
relevant exposure period, should be used rather than 10-day
Health Advisories, except possibly in the (presumably rare)
situation where it can be documented that exposure is extremely
short-term and will not exceed approximately 10 days in duration.
Overview of OW's STAR Methodology
Several toxicity- or risk-based levels developed by OW are
considered in developing STARs. These levels are defined in the
box on the next page. The STAR methodology is described in
detail in OW1s referenced 1992 URTH guidance.
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MCLG (maximum contaminant level goal): A non-regulatory
health goal based solely on considerations of protecting
the public from adverse health effects of drinking water
contamination,
MCL (maximum contaminant level): A regulatory level that
sets the maximum permissible concentration of a contaminant
in water delivered to users of public water systems. The
MCL is set as close to the MCLG as feasible, considering
such factors as analytical capability, treatment
availability, and treatment costs.
DWEL (drinking water equivalent level1: The concentration
of a contaminant in drinking water that is not expected to
cause any adverse non-cancer health effects in humans over
a lifetime of continuous exposure. The DWEL, in mg/1, is
calculated by multiplying the oral reference dose (RfD), in
mg/kg-day, by 70 kg (standard adult body weight) and
dividing it by 2 liters/day (standard adult water
consumption rate).
Longer-term HA (health advisory) (child): The
concentration of a contaminant in drinking water that is
not expected to cause any adverse non-cancer health effects
in children over a continuous exposure period of up to
seven years. The Longer-term HA is calculated similarly to
the DWEL, but instead of the RfD, a no- or lowest-observed-
adverse-effect-level (NOAEL or LOAEL) from a study in which
the exposure duration is comparable to seven years of human
exposure is used. The NOAEL or LOAEL, in mg/kg-day, is
divided by appropriate uncertainty factors, then multiplied
by 10 kg (standard child body weight) and divided by 1
1/day (standard child water consumption rate).
10 4 cancer risk level: The concentration o| a contaminant
in drinking water that would result in a 10* upper-bound
lifetime excess cancer risk to an individual exposed
continuously over a lifetime (other pre-specified risks,
such as 10" , also can be defined). The cancer risk level
is calculated based on the pre-specified risk, the
contaminant's cancer slope factor, the standard adult body
weight of 70 kg, and the standard adult water consumption
rate of 2 1/day.
The level that ultimately becomes the basis for a STAR
depends in part on the type of effects caused by the substance.
Of particular importance in the STAR methodology is a substance's
potential for human carcinogenicity, as reflected in EPA's cancer
weight-of-evidence classification. EPA's classification system
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(described in detail in Guidelines for Carcinogen Risk
Assessment, 51 Federal Register 33992, September 24, 1986)
defines the following major categories;
A Human carcinogen
B Probable human carcinogen
C Possible human carcinogen
D Not classifiable as to human carcinogenicity
E Evidence of non-carcinogenicity
For Group A or B carcinogens, the STAR is set ^t the MCL
whenever the MCL is greater than or equa^ to the 10* cancer risk
level. When the MCL is less than the 10* cancer risk level, the
STAR is the lowest value among the 10* cancer risk level, the
DWEL, or the Longer-term HA (child). As examples of these two
cases, consider ethylene dibromide and benzene.
The STAR for ethylene dibromide is set at th<| MCL, 0. 05
jug/1/ because the MCL is greater than the 10" cancer
risk level, 0.04 ng/1.
Conversely, the STAR for benzene is set at the 10~4
cancer risk level, 1^00 ng/1, because the MCL of 5 ng/l
is less than the 10* cancer risk level (no DWEL or
Longer-term HA (child) available).
For Group D, E, or unrated substances (i.e., substances
considered to be non-carcinogens for purposes of this
methodology), the STAR is set at the MCL whenever a contaminant's
main health effects are very short-term and the MCL is based on
effects of acute exposures. Otherwise, the STAR is the lower of
the DWEL or Longer-term HA (child) values. For example, the DWEL
for methoxychlor is 200 pig/1, the Longer-term HA (child) is 50
ng/1, and the MCL is not based on very short-term effects.
Therefore, the STAR is set at 50 ng/1.
For Group C carcinogens, which have limited evidence for
human carcinogenicity, the STAR is usually based on non-cancer
effects and is the lowest value among the DWEL, the Longer-term
HA (child), or the MCLG multiplied by 10. The 10-fold
adjustment of the MCLG removes the additional safety factor
included in the MCLG for Group C carcinogens to protect against
possible cancers resulting from lifetime exposure, a factor not
considered necessary for developing a STAR. As an example,
consider atrazine, which has a DWEL of 200 [ig/1, a Longer-term HA
(child) of 60 ng/1, and an "MCLG times 10" value of 30 ng/1 (MCLG
equals 3 fig/1) . Therefore, the STAR is set at the lowest of
these three values, or 30 jig/1.
If toxicity information is inadequate to develop a DWEL or
Longer-term HA (child), the MCLG (and therefore the STAR) can be
based on a cancer risk level.
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Development of Numeric RALs Using the STAR Methodology
If a STAR value is available from OW, it is used without
adjustment as the numeric RAL. If OW has evaluated a substance
but has not developed a STAR, the numeric RAL is determined using
the STAR methodology and input data from OW. When an OW
evaluation is unavailable for a substance, a few modifications to
the STAR methodology are necessary because some of the needed
input values may not be available.
For substances lacking an OW evaluation, RALs are based on a
subset of the STAR procedures. MCLs, MCLGs, and Longer-term HAs
(child) are unavailable in these situations and are not
considered; DWELs and cancer risk levels are calculated based on
toxicity information (oral RfDs, oral cancer weight-of-evidence
ratings, and oral cancer slope factors) from other Agency data
sources and then used to determine the RAL. EPA's on-line
Integrated Risk Information System (IRIS) should be the first
source consulted for this toxicity information (assuming no
information is available directly from OW), followed by EPA's
Health Effects Assessment Summary Tables fHEAST) (Office of
Research and Development, March 1992 or most recent update).
Exhibit 1 is a matrix summarizing the new numeric RAL
methodology for both situations - when an OW evaluation is
available for a substance and when an OW evaluation is
unavailable. Exhibits 2A (OW evaluation available) and 2B (OW
evaluation unavailable) are a parallel set of flowcharts
depicting the RAL determination process.
Site-specific RALs
A significant health threat may exist at a site even if no
substance is currently present in drinking water at a
concentration exceeding its numeric RAL. A removal action may be
initiated if the health risk at a site has been analyzed in
detail and the analysis indicates that a serious risk is present
due to site-specific factors. Examples of such factors include
evidence that a ground-water plume with contamination exceeding a
RAL is moving toward drinking water wells, current contaminant
levels will likely increase (e.g., due to increased pumping from
an aquifer anticipated during summer months), people have been
drinking contaminated water for a long period of time already,
multiple contaminants are likely to result in additive or
synergistic effects, or sensitive populations are present and
being exposed to the contamination. OW's URTH guidance, adopted
as the new basis for numeric RALs, provides for similar site-
specific flexibility to depart from recommended STAR levels based
on considerations such as site-specific exposures, exposures from
other sources, past exposure (if known), exposure to mixtures of
drinking water contaminants, population sensitivity, chemical
characteristics such as volatility, or other factors not directly
related to the contaminant.
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Decisions to undertake a removal action when a numeric RAL
has not been exceeded should be made on a case-by-case basis.
Because ERD wishes to know how guidance is used in the Regions,
please notify your Regional Coordinator of any Action Memo
approved for contaminated drinking water sites where the removal
action decision is based solely on site-specific factors (i.e.,
no numeric RAL is exceeded).
Information Sources
The attached table of numeric RALs for drinking water,
dated November 1992, lists values for many substances of concern
at drinking water contamination sites. ERD plans to distribute
updates to the table, as appropriate, such as when OW releases a
significant number of new or revised STARs. In the meantime,
Regional offices should use the most up-to-date STAR available
for a substance as the numeric RAL. If OW has released a revised
STAR that differs from the value given in the attached table,
Regional offices should use that revised STAR as the numeric RAL.
Information on STARs and other OW data used in the new RAL
methodology is available through the Safe Drinking Water Hotline
at 800-426-4791.
If a substance of concern is not listed in the attached
table, Regional offices may determine the appropriate numeric RAL
by applying the methodology summarized in this memorandum (refer
to the OW URTH guidance for a more detailed description of the
STAR procedures). Alternatively, a Regional office may request
ERD1s assistance in determining the appropriate numeric RAL. If
a Region decides to develop a numeric RAL itself, it must first
check with OW to determine if a STAR is available and, if not,
whether OW has developed any of the other risk-based levels
needed as inputs (e.g., MCL/MCLG, DWEL, Longer-term HA (child),
10 cancer risk level). If there is no information available
from OW, the Regional office may calculate and use DWELs and
cancer risk levels to develop numeric RALs, based on toxicity
information in IRIS or HEAST. For additional information on
IRIS, contact user support in the Office of Research and
Development, Cincinnati, OH, at 513-569-7254. For additional
information on HEAST, contact the Superfund Health Risk Technical
Support Center in the Office of Research and Development,
Cincinnati, OH, at 513-569-7300.
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Substances With Significant Changes in Numeric RALs
Exhibit 3 lists those substances for which the RAL has
changed significantly (defined as more than a factor of two) from
the value in the table distributed by ERD in April 1991.
Please distribute this update to all removal program staff
in your Regional office. If you have any questions on this
document, contact Lisa Boynton (OERR/ERD), at 703-603-9052.
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EXHIBIT 1
SUMMARY OF NEW METHODOLOGY FOR NUMERIC RALs
Cancer
Veight-
of-evidence
Class
OW Evaluation of
Substance Available
OW Evaluation of .
Substance Unavailable
A or B
•If MCL > 10 4 cancer risk
level;
RAL = MCL
•If MCL < 10~4 cancer risk
level:
RAL = lowest of:
10~4 cancer risk level, or
DWEL, or
Longer-term HA (child)
•RAL = lower of:
10 4 cancer risk level, or
DWEL
C
•RAL = lowest of:
MCLG x 10, or
DWEL, or
Longer-term HA (child)
•If DWEL can be calculated:
RAL = DWEL x 0.2
(20% relative source
contribution assumed)
•If DWEL cannot be
calculated:
RAL = 10~4 cancer risk level
D, E, or
unrated
•If MCL based on acute
toxicity:
RAL = MCL
•If MCL not based on acute
toxicity:
RAL = lower of:
DWEL, or
Longer-term HA (child)
•RAL = DWEL
1 Use OW values for HCL, MCLG, DWEL, Longer-term HA (child), and 10 4 cancer
risk level.
2
Obtain oral RfD, oral cancer weight-of-evidence rating, and oral cancer
slope factor from IRIS (or HEAST if unavailable in IRIS), then calculate DWEL
and 10" cancer risk level.
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EXHIBIT 2A
DECISION FLOW DIAGRAM FOR RAL METHODOLOGY:
OFFICE OF WATER EVALUATION AVAILABLE
no
yes
MCL >10-4 ?
Cancer A or B ?
yes
no
yes
Cancer C ?
no
no
MCL based on
acute toxicity ?
yes
RAL = MCL
RAL = MCL
START
MCLG x 10,
or DWEL,
or Longer-term HA (child)
RAL = lowest of:
DWEL,
or Longer-term HA (child)
RAL = lower of:
10-4 cancer risk level,
or DWEL,
or Longer-term HA
RAL = lowest of:
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EXHIBIT 2B
DECISION FLOW DIAGRAM FOR RAL METHODOLOGY:
OFFICE OF WATER EVALUATION NOT AVAILABLE
yes
Cancer A or B ?
no
yes
Cancer C ?
no
START
RAL = 10-4 cancer risk level
if DWEL is unavailable:
RAL = DWEL x 0.2
RAL = DWEL
10-4 cancer risk level,
or DWEL
RAL = lower of:
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EXHIBIT 3
SUBSTANCES FOR WHICH NUMERIC RALs HAVE CHANGED SIGNIFICANTLY
Substance
1991 (Old)
RAL
New RAL
(Pg/D
Factor
Increase^
Decrease
ORGANICS
Acifluorfen (Tackle)
460
100
-4.6
Acrylonitrile
6.5
1
-6.5
Aldicarb (Temik)
2.5
7
+2.8
Atrazine
180
30
-6.0
Baygon
140
40
-3.5
Bromodichloromethane
27
60
+2.2
Bromomethane
25
50
+2.0
Carbaryl
3,500
1,000
-3.5
Carbofuran
180
50
-3.6
Carbon tetrachloride
12
30
+2.5
Carboxin
3,500
1,000
-3.5
Chloramben
530
200
-2.7
Chlorod ibromome thane
42
700
+17
Chloromethane
270
100
-2.7
Chlorophenol (2-)
180
50
-3.6
Chlorothalonil
530
150
-3.5
Chlorotoluene (o-)
350
700
+2.0
Chlorpyrifos
110
30
-3.7
Cyanazine
70
20
-3.5
2,4-D (2,4-Dichloro-
phenoxyacetic acid)
350
100
-3.5
Dacthal (DGPA)
18,000
5,000
-3.6
Dalapon
1,100
300
-3.6
Diazinon
32
3
-11
Dicamba
46
300
+6.5
Dichlorobenzene (1,4-)
150
750
+5.0
Dichloroethylene (1,1-)
5.8
70
+12
Dichlorophenol (2,4-)
110
30
-3.7
Dimethyl phthalate
35,000
350,000
+10
Dinoseb
35
10
-3.5
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EXHIBIT 3 (continued)
SUBSTANCES FOR WHICH NUMERIC RALs HAVE CHANGED SIGNIFICANTLY
Substance
1991 (Old)
RAL
(liR/1)
New EAL
Factor
Increase^
Decrease
Dioxane (1,4-)
320
700
+2.2
Diphenamid
1,100
300
-3.7
Endothall
700
200
-3.5
Endrin
11
3
-3.7
Ethylene glycol
70,000
6,000
-12
Fonofos
70
20
-3.5
Glyphosate
3,500
1,000
-3.5
Hexane (n-)
21.000
4,000
-5.3
Isophorone
850
7,000
+8.3
Isopropylbenzene (Cumene)
1,400
14,000
+10
Malathion
700
200
-3.5
Maleic hydrazide
18,000
5,000
-3.6
MCPA ((4-Chloro-2-
methylphenoxy)-acetic acid)
18
50
+2.8
Methorny1
880
300
-2.9
Methoxychlor
180
50
-3.6
Metolachlor
5,300
2,000
-2.7
Metrlbuzin
880
300
-2.9
Oxamyl (Vydate)
880
200
-4.4
Paraquat
160
50
-3.2
Pentachloronitrobenzene
14
100
+7.2
Phenol
21,000
6,000
-3.5
Picloram
2,500
700
-3.6
Prometon
530
200
-2.7
Pronamide (Kerb)
2,600
800
-3.3
Propachlor
460
100
-4.6
RDX (Hexahydro-1,3,5-
trinltro-1,3,5-triazine)
32
100
+3.2
Styrene
3,500
1,000
-3.5
TCDD (2,3,7,8-) (Dioxin)
22 pcg/1
50 pcg/1
+2.3
Tebuthiuron
2,500
700
-3.6
Terbufos
3.5
1'
-3.5
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EXHIBIT 3 (continued)
SUBSTANCES FOR WHICH NUMERIC RALs HAVE CHANGED SIGNIFICANTLY
Substance
1991 (Old)
RAL
(HR/1)
New RAL
Cng/D
Factor
Increase^
Decrease
Tetrachloroethane (1,1,1,2-)
130
900
+6.9
Tetrachloroethane (1,1,2,2-)
18
2
-9.0
2,4,5-TP (2(2,4,5-
Trichlorophenoxy)propionic
acid)
280
70
-4.0
Trichlorobenzene (1,2,4-)
46
100
+2.2
Trichloroethane (1,1,2-)
61
30
-2.1
Trifluralin
260
80
-3.3 '
INORGANICS
Arsenic
2
50
+25
Barium
1,800
5,000
+2.8
Boron
3,200
900
-3.6
Cadmium
18
5
-3.6
Cyanide
700
200
-3.5
Fluoride
2,100
5,000
+2.4
Maganese
3,500
200
-17
Molybdenum
140
10
-14
Nitrite
3,500
1,000
-3.5
Vanadium
250
30
-8.3
Zinc
7,000
3,000
-2.3
-J
The ratio between the new RAL and the old RAL. A "+" indicates that
the RAL has increased, while a indicates that the RAL has decreased.
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NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
Tables
Emergency Response Division
Office of Solid Waste and Emergency Response
U.S. Environmental Protection Agency
Washington, DC 20460
May 1993
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Table Acronyms
CAS #
DWEL
Longer-term HA (Child)
MCL
MCLG
MFL
Treat. Tech.
URTH-STAR
Chemical Abstract Number
Drinking Water Equivalent Level (calculated by multiplying the oral RfD by 70 kilograms (adult
body weight) and dividing by the average volume of water (2 liters) consumed per day)
Drinking Water Health Advisory for 10 kg child consuming 1 liter water per day for up to 7 years
Maximum Contaminant Level (National Primary Drinking Water Standard)
Maximum Contaminant Level Goal
Million Fibers per Liter
MCL is based on the capability of the treatment technology
Draft Short-term Risk Level (STAR) recommended for an Unreasonable Risk to Health (URTH)
under Safe Drinking Water Act
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NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
ORGANICS
CAS#
Cancer Risk
Standards and Health Advisories
Superfund
Removal
Action
Level
(Pg/L)
Cancer
Group
lr4
Cancer
Risk
(pg/L)
DWEL
0>g/L)
Longer-
term HA
(Child)
(pig/L)
MCL/MCLG
(Pg^)
URTH
-STAR-
Lcvel
(jig/L)
Acenaphthene
83329
—
—
2,100
—
—
—
2,100
Acetone
67641
D
¦ —
3,500s
— -
.. — " "
3,500
Acifluorfen (Tackle)
62476599
B2
100
400
100
-10
—
100
Acrylamide (2-Propenamide)
79061
B2
1
7
20
Treat. Tech. / 0
•; 7 1
1 ' ¦
Acrylonitrile
107131
B1
6
—
—
-/O
—
6
Adipates (Diethyihwyl)
103231
C
, —
20,000
—
500 / 500
;—¦.
5,000
AJachlor
15972608
B2
40
400
—
2/0
40
40
Aldicarb (Temik)
116063
D
¦ ' —
35
:
3/1
. .
. • 35
Aldicarb sulfone
1646884
D
—
35
2/1
35
Aldicarb sulfoxide
—.
D
35
.
4/1
35
Aldrin
309002
B2
0.2
1
0.3
—
—
0.2
Ametyrn
834128
D
' • L— ¦
300
900
• -—. V'-.
300
Ammonium sulfamate
7773060
D
—
8,000
20,000
—
—
8,000
Anthracene
120127
D
11,000
. _
- —
11,000
Atrazinc
1912249
C
—
200
60
3/3
30
30
Baygon
114261
c
100
40
. - —V;
40
Bentazon
25057890
D
—
90
300
— / 20
—
90
Benz(a)anthracene
56553
B2
— '
¦ —
0.1/0
0.1
Benzene
71432
A
100
—
—
5/0
100
100
Benzo(a)pyrene
50328
B2
—
_ .
0.2/0
G-2
Benzo(b)fluoranthene
205992
B2
—
—
0.2/0
—
0.2
Benzo(k)fIuoranthenc
207089
B2
—
0.2/0
0.2 ;
bis-2-Chloroisopropyl ether
108601
D
—
1,000
4,000
—
—
1,000
Bromacil
314409
.. C
5,000
3,000
i'.—r-
3,000
B romoch loromethane
74975
D*
—
500
1,000
—
—
500
Bromodichloromethane
75274
: B2
700
4,000
100/0
__
60
Bromoform
75252
B2
400
700
2,000
100/0
—
400
-------
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
Cancer Risk
Standards and Health Advisories
Superfund
ORGANICS
CAS#
Cancer
10-4
Cancer
DWEL
Longer- J
term HA [
MCL / MCLG
URTH
-STAR-
Removal
Action
Group
Risk
(Pi/L)
(pg/L)
(Chfld)
(pg/L) j
(pg/L)
Level
(pg/L)
Level
(pjg/L.)
Bromomethane (Methyl bromide)
74839
D
, — .
40
100
—
40
Butanone (2-) (see Methyl ethyl ketone)
Butyl benzyl phthalate
85687
C
—. .
6,000
100/0
6,000
Butylate
2008415
D
—
2,000
1,000
—
—
1,000
Carbaryt
63252
D
—>
4,000
1,000
" — -
¦ •*-' ¦
1,000
Carbofuran
1563662
E
—
200
50
40/40
50
50
Carbon tetrachloride
56235
B2
30
30
70
5/0
30
30
Carboxin
5234684
D
—
4,000
1,000
—
—
1,000
Chloral hydrate (Trichloroacetaldehyde
monohydrate)
302170
C
—
70
200
— / 60
70
Chloramben
133904
D
—
500
200
—
—
200
Chlordane
57749
B2
3
2
—
2/0
:: 2
2
Chlorobenzene (see Monochiorobenzene)
Chlorodibromomethane (Dibiomochlcwo-
124481
C
- ¦ __ -
700
2,000
100/0
700
methane)
Chloroform (Trichloromethane)
67663
B2
600
400
100
100/0
—
100
Chloromethane (Methyl chloride)
74873
C
—.
100
400
.—. .
100
Chlorophenol (2-)
95578
D
—
200
50
—
—
50
Chlorothalonil
1897456
B2
150
500
200
—
\
150
Chlorotoluene, o-
95498
D
—
700
2,000
—
700
Chlorotoluene, p-
106434
D
' ¦, —
700
2,000
: ~'
700
Chlorpyrifos
2921882
D
—
100
30
—
—
30
Chrysene
218019
B2
::
' —
' '' '
0.2/0
0.2
Cumene (see Isopropylbenzene)
Cyanazine
21725462
C
• •
70
20
' " : —'•
::;v
20
2,4-D (2,4-Dichlorophenoxyacetic acid)
94757
D
—
400
100
70/70
100
100
Daethal (DCPA)
1861321
D
20,000
5,000
: —•
—::
5,000
Dalapon
75990
D
—
900
300
200 / 200
—
300
-------
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
Cancer Risk
Standards and Health Advisories
Superfnnd
ORGANICS
CAS#
Cancer
19*
Cancer
DWEL
L
Di[2-ethylhexyl]adipate
103231
C
3,000
20,000
20,000
400 / 400
—
4,000
Diazinon
333415
E
—
3
5
—
—
3
Dibenzo[a,h]anthracene
53703
B2
__
—
. __
0.3/0
0.3
Dibromoacetonitrile
3252435
C
—
800
2,000
—
—
800
Dibromochloromethane (see Chtorodibromomethane)
Dibromochloropropane (DBCP)
96128
B2
3
—
—
0.2/0
3
3
Dibromomethanc (Methylene Bromide)
74953
D
—
—
—
.;__
¦ —
Dibutyl phthalale (Di-11-butyl phthalate)
84742
D
—
4,000
—
—
4,000
Dicamba
1918009
D
—
1,000
300
_
' .
300
Dichloroacelic acid
79436
B2
—
300
5,000
-/o
300
Dichloroacetonitrilc
3018120
C
_
300
800
.• ' - —^
/
300
Dichlorobenzene -o (1,2-)
95501
D
—
3,000
9,000
600 / 600
3,000
3,000
Dichlorobenzene -m (1,3-)
541731
D
• _
3,000
9,000
600 / 600
¦¦¦
3,000
Dichlorobenzene -p (1,4-)
106467
C
—
4,000
10,000
75 / 75
750
750
Dichlorodifluoromethane (Freon-12)
75718
D
—
5,000
9,000
—
5,000
Dichloroethane (1,1-)
75343
C8
—
3,500®
—
—
—
3,500
Dichloroethane (1,2-) (Ethylene
107062
B2
40
. . ¦ . —¦
700
5/0
40
40
di chloride)
Dichloroethylene (1,1-)
75354
C
—
400
1,000
7/7
70
70
Dichloroethylene (cis- 1,2-)
156592
D
—
400
3,000
70/70
I 400
400
Dichloroethylene (trans- 1,2-)
156605
D
—
600
2,000
100 / 100
600
600
Dichloromethane (Methylene chloride)
75092
B2
500
2,000
- •"
5/0
• : :
500
Dichlorophenol (2,4-)
120832
D
—
100
30
—
—
30
Dichloropropane (1,2-)
78875
B2
¦ >—
—
' — .'
5/0
—
"• 5 .
Dichloropropene (1,3-) (cis and trans)
542756
B2
20
10
30
— / 0
—
10
Dieldrin
60571
B2
0.2
2
Vf,,; 0.5 ?
:;:V—: :
' —: '
O-2
Diethyl phthalate
84662
D
¦—
30.000
—
—
—
30,000
Diethylhexyl (see Adipates)
-------
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
Cancer Risk
Standards and Health Advisories
Superfund
ORGANICS
CAS#
Cancer
10"4
Cancer
DWEL
Longer-
term HA
MCL/MCLG
URTH
-STAR-
Removal
Action
Group
Risk
(Child)
Levd
Level
(Pg/L)
(Pg/L)
(MK/L)
Cpg^L)
-------
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
Cancer Risk
Standards and Health Advisories
Superfund
ORGANICS
CAS#
Cancer
Iff"4
Cancer
DWEL
Longer-
term HA
MCL/MCLG
URTH
-STAR-
Removal
Action
Group
Risk
(CUM)
Level
Level
-------
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
Cancer Risk
Standards and Health Advisories
Superfund
ORGANICS
CAS#
Cancer
ir*
Cancer
DWEL
Longer-
term HA
MCL/MCLG
URTH
-STAR-
Removal
Action
Group
Risk
(Child)
Level
Level
(m/l)
(Mg/L)
(Hg/L)
-------
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
ORGANICS
CAS#
Cancer Risk
Standards and Health Advisories
Superfund
Removal
Action
Level
900
Tetrachloroe thane (1,1,2,2-)
79345
e
20s
—
—
—
2
Tetrachioroeth ylene (Peiehloroethytae)
127184
B2a
70
500
1,000
5/0
70
70
Toluene
108883
D
—
7,000
2,000
1,000/ 1,000
—
2,000
Toxaphene (Octachlorocamphene)
8001352
B2
- 3
' 3 v
— •
3/0
&
3 .
TP (2,4,5-) (2(2,4,5-Trich]oraphenoxy-
93721
D
300
70
50/50
70
70
propionic acid)
Trichloroacetaldehyde (Chloral) see Chloral hydrate (hydraied foim of trichloroacetaldehyde)
Trichloroacetic acid
76039
C
1,300
4.000
— / 100
—
1,000
Trichlorobenzene (1,2,4-)
120821
D
• .t
400
100
70/70
—
100
-------
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
ORGANICS
CAS#
Cancer Risk
Standards and Health Advisories
Superfund
Removal
Action
Level
(P*g/L)
Cancer
Group
kt4
Cancer
Risk
(pg/L)
DWEL
Longer-
term HA
(Child)
(Mg/L)
MCL/MCLG
(Pg/L)
IIRTH
-STAR-
Level
(Pfi/L)
Trichlorobenzene (1,3.5-)
108703
D
—
200
600
—
—
200
Trichloroethane (1,1,1-)
71556
D
—. •
1,000
40,000
200 / 200
1,000
1,000
Trichloroethane (1,1,2-)
79005
C
—
100
400
5/3
—
30
Trichloroethylene (Trichloroethene)
79016
B2
300
300
—
5/°
300
300
Triehloromethane (see Chloroform)
Trichlorophenol (2,4,6-)
88062
B2
300
—:
—-
• : —1 •.
300
Trichlorophenoxypropionic acid (2(2,4,5-)) (see 2,4,5
-TP)
Trichloropropane (1,2,3-)
96184
B2
—•
200
600
—
200
1,1,2-Trichloro-1,2,2-lrifluoroethane (see Freon 113)
Trifluralin
1582098
C
—
300
80
: —
80
Trinitroglycerol
55630
—
—
—
5
—
—
5
Trinitrotoluene (2,4,6-)
118967
c
100
20
20
—-
20
Vinyl chloride
75014
A
1.5
—
10
2/0
2
2
Vydate (see Oxamyl)
Xylenes (mixed)
1330207
D
—
60,000
40,000
10,000 / 10,000
40,000
40,000
a Based on data from IRIS or HEAST in the absence of a published U.S. EPA, Office of Water value
b Technical Grade (tg); 2,4- and 2,6-Dinitrotoluene are unlikely to occur alone
c Based on special considerations
-------
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
Cancer Risk
Standards and Health Advisories
Saperfund
INORGANICS
CAS#
Cancer
ID"4
Cancer
DWEL
Longer-
term HA
MCL/MCLG
URTH
-STAR-
Removal
Action
Group
Risk
(Child)
Level
Level
(fig/L)
0*^L)
(M^)
\-.(pg/k).'.
WD
. (mfc)
Ammonia
7664417
D
—
—
—
—
—
34,000s
(taste)
Antimony
7440360
D
15
¦ 15 v.;
6/6
:
15 : '
Arsenic
7440382
A
2
—
—
50/ —
—
50
Asbestos >10 pm
1332214
A
700 MFL
; —
—
7 MFL / 7 MFL
70 MFL
70MFLb
Barium
7440393
D
—
2,000
—
2,000 / 2,000
—
2,000
Beryllium
7440417
B2
0.8
200
4,000
4/4
i
Boron
7440428
D
—
3,000
900
—
900
Cadmium
7440439
D
—
20
' 5
5/5
5
5
Chloramines
10599903
D*
—
3,300
1,000
— /4,000
1,000
Chlorine
7782505
D
__ ¦
¦ —
— -:
— / 4,000
Chlorine dioxide
10049044
D
—
100
—
—/80
100
Chromium III (see Chromium total)
16065831
Chromium VI (see Chromium total)
18540299
Chromium (total)
¦' —¦
D
—
200
200
100/100
200
200
Copper
7440508
D
—
—
—
Treat T. / 1,300
1,300
1,300
Cyanide
57125
D
: —
800
200
200/200
3;.¦—
200
Fluoride
16984488
—
—
—
—
4,000 / 4,000
5,000=
5,000
Hypochlorite
7681529
—
—
—
— /4,000
Hypochlorous acid
7790923
—
—
—
—
— / 4,000
—
Lead at tap
7439921
B2
•]' —'
¦ '
Treat. Tech. /0
30°
: 30 .
Manganese
7439965
Da
—
200
—
—/200
—
200
Mercury
7439976
D
__
10
— •, ¦
3 12 v.
10 :
10
Molybdenum
7439987
D
—
200
10
—
—
10
Nickel
7440020
D
'
600
: 500
100/100
500
Nitrate
14797558
D
56,000
—
10,000/ 10,000
10,000
10,000
Nitrite
14797650
. ¦
1^00/1^00
1,000
1,000
Nitrate+Nitrite
—
—
—
10,000/ 10,000
10,000
10,000
-------
2
NUMERIC REMOVAL ACTION LEVELS FOR CONTAMINATED DRINKING WATER SITES
PRIMARY DRINKING WATER STANDARDS AND HEALTH ADVISORIES
May 1993
Chemical
INORGANICS
CAS#
Cancer Risk
Standards and Health Advisories
Superfund
Removal
Action
Level
(jigfl*)
Cancer
Group
10-4
Cancer
Risk
(pg/L)
DWEL
(J»g/L)
Longer-
term HA
(Child)
Cm®-)
MCL / MCLG
------- |