United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
Publication 9234.2-15/FS
August 1991
ARARs Q's & A's:
Compliance with New SDWA
National Primary Drinking Water Regulations
for Organic and Inorganic Chemicals
Office of Emergency and Remedial Response
Office of Program Management OS-240
Quick Reference Fact Sheet
Section 121(d) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as
amended by the 1986 Superfund Amendments and Reauthorization Act (SARA), requires that on-site remedial actions must
attain or waive Federal or more stringent State applicable or relevant and appropriate requirements (ARARs) upon
completion of the remedial action. The 1990 National Oil and Hazardous Substances Pollution Contingency Plan (NCP)
requires compliance with ARARs during remedial actions as well as at their completion, and compels attainment of ARARs
during removal actions to the extent practicable, considering the exigencies of the situation. (See NCP, 55 FR 8666, 8852
(March 8,1990)(codified at 40 CFR 300.435(bX2)), and 55 FR 8666,8843 (March 8,1990)(codified at 40 CFR 300.415(0).
To implement the ARARs provision, EPA developed guidance, CERCLA Compliance With Other Laws Manual:
Parts I and II (Publications 9234.1-01 and 9234.1-02), and has provided training to Regions and the States on the
identification of and compliance with ARARs. EPA also is preparing a series of short fact sheets to provide guidance on
a number of questions that arose in developing ARAR policies, and in identifying and complying with ARARs at specific
sites. This particular fact sheet addresses compliance with new Safe Drinking Water Act (SDWA) National Primary
Drinking Water Regulations for organic and inorganic chemicals, which were promulgated on January 30, 1991. (See 56
FR 3526 January 30, 1991. to be codified at 40 CFR Parts 141, 142, and 143.)
Ql. What are these National Primary
Drinking Water Regulations?
A. These National Primary Drinking Water
Regulations (NPDWRs) establish Maximum
Contaminant Level Goals (MCLGs) and
Maximum Contaminant Levels (MCLs) for
31 organic and inorganic contaminants,
which are effective July 30,1992. They also
repropose MCLGs and MCLs for 5
additional contaminants (aldicarb, aldicarb
sulfoxide, aldicarb sulfone,
pentachlorophenol, and barium) that were
originally promulgated on July 8, 1987 and
will become effective January 1, 1993.
Finally, these regulations promulgate
MCLGs and treatment technique
requirements for acrylamide and
epichlorohydrin. See Highlight 1 for the
definitions of MCLs and MCLGs. For the
full text of these SDWA regulations, see 56
FR 3526 (January 30, 1991). See Highlight
3 for a list of the contaminants and their
corresponding MCLs and MCLGs.
Q2. Are MCLs potential ARARs for CERCLA
sites?
A. Yes. CERCLA section 121(d)(2)(A)(i)
requires on-site CERCLA remedial actions to
attain or waive the "standards" or "levels of
control" issued under the SDWA (i.e.,
MCLs) where they are applicable or relevant
and appropriate. (Note: As mentioned in
the introduction to this fact sheet, the NCP
extends the statutory ARARs requirement to
removals, to the extent practicable
considering the exigencies of the situation, as
well as remedial actions. (See section
300.415(i)(l) and (2) of the NCP, 55 FR
8843.)
MCLs are potentially relevant and
appropriate during a CERCLA cleanup for
ground or surface waters that are current or
potential sources of drinking water. Since
ground water contamination sites account for
approximately 70 percent of all sites on the
National Priorities List, these potentially
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relevant and appropriate requirements are
triggered frequently at CERCLA sites.
In addition, MCLs also may be applicable
where water at a CERCLA site is delivered
through a public water supply system, if that
system has at least 15 service connections or
serves at least 25 year-round residents.
Since CERCLA projects only rarely treat tap
water, however, there will be few instances
in which MCLs are applicable for
groundwater cleanup at a CERCLA site.
(See NCP Preamble, 55 FR 8750 and
CERCLA Compliance With Other Laws
Manual, Part I. Publication 9234.1-01,
August 1988, page 4-8.)
REMINDER: It makes a difference
whether a requirement is applicable or
relevant and appropriate. The
"applicability" determination is a legal one,
and it provides the Agency with very little
flexibility. The "relevant and appropriate"
determination is a site-specific determination,
which provides the Agency with much
greater flexibility since the Agency may
determine that a requirement is not
"appropriate", given site circumstances.
(Therefore it would not be an ARAR for that
site.) Waivers are also available if the
requirement is relevant and appropriate but
cannot be met for one of the reasons set out
in CERCLA section 121(d)(4) (e.g., the
ground water is a potential drinking water
source and thus the MCL is relevant and
appropriate, but attainment of the MCL is
technically impracticable).
In contrast, an applicable requirement, once
triggered at a site, must simply be met or
waived. (For additional information on this
issue, see "ARARs Q's and A's: General
Policy. RCRA. CWA. SDWA &
Administrative Record."
9234.2-01/FS-A, July 1991.)
Publication
Q3. Are MCLGs potential ARARs for
CERCLA sites?
A. Yes. Section 121(d)(2)(A) of CERCLA also
requires on-site remedial actions to attain
MCLGs under the SDWA "where they are
relevant and appropriate under the
circumstances" of the release or threatened
release. Under the NCP, EPA requires that
MCLGs set at levels above zero (i.e.,
non-zero MCLGs) be attained during a
CERCLA cleanup where they are relevant
and appropriate (i.e., generally for ground or
surface waters that are current or potential
sources of drinking water). If the MCLG is
equal to zero, EPA determined under the
NCP that the MCLG is not appropriate for
setting cleanup levels. In those
circumstances, the corresponding MCL will
be the potentially relevant and appropriate
requirement. (See section 300.430(e)(2)(i)
(B) and (Q of the NCP, 55 FR. 8848.)
REMINDER: Although MCLGs are
potentially relevant and appropriate, they are
never applicable requirements at a CERCLA
response action because they are not
enforceable "standards" or "levels of
control."
Highlight 1:
Definitions of MCLs and MCLGs
Maximum Contaminant Levels
(MCLs) are enforceable standards
that apply to specified contamin-
ants which EPA has determined to
have an adverse effect on human
health above certain levels. MCLs
are set as close as feasible to
MCLGs. Feasibility takes into
account both technology and cost
considerations.
Maximum Contaminant Level
Goals (MCLGs) are non-
enforceable health-based goals that
have been established at levels at
which no known or anticipated
adverse effects on the health of
persons occur and which will allow
an adequate margin of safety.
See NCP Preamble, 55 FR 8750-
8752.
Q4. What is the status of these regulations as
potential ARARs for CERCLA projects?
A. These regulations were promulgated on
January 30, 1991. The final MCLs and
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Highlight 2: Status of Potential TBCs, RARs, and ARARs
Number of Final/
Reproposed
MCLGs/MCLs
22 Final Non-Zero MCLGs
31 Final MCLs
2 Treatment Techniques
4 Reproposed Non-Zero
MCLGs
5 Reproposed MCLs
Potential To
Be Considered
(TBC)
(Not Pertinent)
(Not Pertinent)
(Not Pertinent)
1/31/91 - 7/91 1
1/31/91 - 7/91 1
Potential
Relevant and
Appropriate (RAR)
1/30/91 & Beyond
1/30/91 - 7/29/92
1/30/91 - 7/29/92
7/91 1 & Beyond
7/91 n- 1/93'
Potential Applicable,
or Relevant and
Appropriate (ARAR)
Not Applicable
7/30/92 and Beyond
7/30/92 and Beyond
Not Applicable
1/93' and Beyond
'Anticipated promulgation date
'Anticipated effective date
non-zero MCLGs for the 31 contaminants
became potential relevant and appropriate
requirements for all decision documents (i.e.,
Records of Decision (RODs) and Action
Memoranda) signed on or after January 30.
1991. Because of the delayed effective date,
the final MCLs for the 31 contaminants may
be relevant and appropriate, but not
applicable, for response actions carried out
during the interim period prior to the
effective date (i.e.. between January 30.1991
and July 29. 1992X In addition, the final
non-zero MCLGs may be relevant and
appropriate. For decision documents signed
on July 30.1992 and beyond, the MCLs for
the 31 contaminants may be applicable or
relevant and appropriate to the cleanup of
ground water. See Highlight 2 for the status
of these regulations, outlining the critical
dates for final and reproposed MCLGs and
MCLs.
In contrast, the reproposed MCLs and
non-zero MCLGs for the 5 additional
contaminants are on a different regulatory
track. They became potential criteria "to be
considered" (TBCs) for all decision
documents signed after January 30.1991 and
up to promulgation (on July 1. 1991).
Because of the delayed effective date, for all
decision documents signed between the date
of promulgation (July 1. 1991) and the
effective date (expected in January 1993).
these MCLGs and MCLs may be relevant
and appropriate, but not applicable. On their
effective date (scheduled for January 1993)
and beyond, the MCLs for the 5 additional
contaminants may be applicable, or relevant
and appropriate.
Q5. Are treatment techniques for drinking
water contaminants in these regulations
potential ARARs for CERCLA cleanups?
A. Generally, no. These NPDWRs have
established treatment techniques for
acrylamide and epichlorohydrin. These
treatment techniques limit the amounts of
acrylamide and epichlorohydrin that drinking
water suppliers may add to treat
contaminated drinking water. Since
CERCLA projects generally do not supply
drinking water as pan of response actions,
and often would be cleaning up contaminated
ground water through methods (e.g., air
stripping or natural attenuation) which do not
involve the addition of these substances to
treat contaminated ground water, these
treatment techniques generally would not be
relevant and appropriate requirements for the
treatment of acrylamide and epichlorohydrin
already found in the ground water.
However, if a CERCLA project is supplying
drinking water as part of the response action
and is adding these substances as part of the
treatment process, the treatment techniques
would be potential ARARs.
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Highlight 3: Jan. 30, 1991
Inorganics
Asbestos
Barium
Cadmium
Chromium
Mecury
Nitrate
Nitrite
Total Nitrate and Nitrite
Selenium
Organlcs
o-Dichlorobenzene
cis-1 , 2-Dtehloroethylene
trans-1 , 2-Dichtoroethylene
1 , 2-Dichloropropane
Ethylbenzene
Monochlorobenzene
Styrene
Tetrachloroethylene
Toluene
Xylenes (total)
Pestlcldes/PCBs
Alachlor
Aldicarb
Aldicarb sulfoxide
Aldicarb sulfone
Atrazine
Carbofuran
Chlordane
Dibromochloropropane (DBCP)
2,4-D
Ethylene dibromide (EDB)
Heptachlor
Heptachlor epoxide
Lindane
Methoxychlor
Polychlorinated biphenyls
(PCBs) (as decachlorobiphenyl)
Pentachlorophenol
Toxaphene
2, 4, 5-TP (Silvex)
National Primary Drinking Water Regulations
1/91
Final
MCLGs
7.0 MFL
—
0.005
0.1
0.002
10.0 (as N)
1.0(asN)
10.0 (as N)
0.05
0.6
0.07
0.1
0
0.7
0.1
0.1
0
1.0
10.0
0
—
—
—
0.003
0.04
0
0
0.07
0
0
0
0.0002
0.04
0
—
0
0.05
1/91
Final
MCLs<
7.0 MFL
—
0.005
0.1
0.002
10.0 (as N)
1.0(asN)
10.0 (as N)
0.05
0.6
0.07
0.1
0.005
0.7
0.1
0.1
0.005
1.0
10.0
0.002
—
—
—
0.003
0.04
0.002
0.0002
0.07
0.00005
0.0004
0.0002
0.0002
0.04
0.0005
—
0.003
0.05
1/91
Reproposed
MCLGs
2
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0.001
0.001
0.001
—
—
—
—
—
—
—
—
—
—
—
0
—
1/91
Reproposed
MCLS'
—
2
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
-
0.003
0.004
0.002
—
—
—
—
—
—
—
—
—
—
—
0.001
—
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Q6. How will these regulations affect
CERCLA RODs that were signed prior to
January 30,1991?
A. These MCLGs and MCLs should not affect
CERCLA RODs that were signed prior to
January 30, 1991. The NCP states that
ARARs "freeze" at the time of ROD
signature, and newly promulgated
requirements need only be met where
necessary for protectiveness. See section
300.430(f)(l)(ii)(B)(l) of the NCP, 55 FR
8850. This means that only requirements
which are promulgated (i.e., published as
final regulations) prior to the date of ROD
signature are potential ARARs for those
RODs. Since these SDWA requirements
were not promulgated until January 30,1991,
they would not be ARARs for RODS signed
before that date.
While these requirements would constitute
"newly promulgated requirements" for pre-
1/30/91 RODs, they are not expected to
require changes to existing RODs during the
five-year protectiveness review of the
remedy. These new SDWA requirements are
not replacing any MCLGs or MCLs that
were outside the CERCLA risk range, with
standards inside that risk range. Therefore,
they should not require any remedy revisions
to maintain protectiveness during the five-
year review. (See also NCP Preamble, 55
FR8757.)
Q7. Are there other requirements in these
regulations that may be ARARs or TBCs
for CERCLA cleanups?
A. Yes. These regulations also contain
monitoring requirements which may be
ARARs when a CERCLA project supplies
drinking water to affected communities as
part of the response action. (See NCP
Preamble, 55 FR 8757.) The regulations
also contain administrative recordkeeping
and reporting requirements. Although such
requirements are neither ARARs nor TBCs,
the Regions are strongly encouraged to
consult with other agencies, as appropriate,
to ensure coordination. (See NCP Preamble,
55 FR 8757.)
Q8. Are there other proposed or promulgated
SDWA regulations that are potential
ARARs or TBCs for CERCLA actions?
A. Yes. On June 7, 1991, EPA promulgated
final MCLGs for lead and copper (see 56 FR
26461, June 7, 1991). Copper now has an
MCLG of 1.3 parts per million. This is a
potential relevant and appropriate
requirement for CERCLA ground and
surface water remediation. However, the
MCLG for lead was set at zero, which is not
considered to be an "appropriate" standard
for CERCLA cleanups. (See NCP Preamble,
55 FR 8751-8752.) This SDWA regulation
did not set any MCLs for either contaminant,
but it did set a treatment technique for lead
which is a potential ARAR. (Note: EPA is
planning to provide additional ARARs
guidance on lead in the near future.)
In addition, NPDWRs for 24 contaminants
were proposed on July 25,1990 (see 55 FR.
30370, July 25,1990). From July 25,1990
until their expected promulgation (expected
in March 1992), the MCLs and non-zero
MCLGs found in these proposed regulations
constitute TBCs for the cleanup of ground
water and may be considered for decision
documents signed during that period. See
Highlight 4 for a chart of the 24
contaminants and their corresponding
proposed MCLs and MCLGs.
This fact sheet does not address two other
SDWA regulations: Final, for 8 volatile
organic compounds, on July 8,1987 (see 52
FR 25690), and, proposed, for the
radionuclides radon, uranium, and radium, on
July 18, 1991 (see 56 FR 33050).
NOTICE: The policies set out in this fact
sheet are not final Agency action, but are
intended solely as guidance. They are not
intended, nor can they be relied upon, to
create any rights enforceable by any party in
litigation with the United States. Response
personnel may decide to follow the guidance
provided in this fact sheet, or to act at
variance with the guidance, based on an
analysis of site-specific circumstances. The
Agency reserves the right to change this
guidance at any time without public notice.
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Highlight 4: Proposed National Primary Drinking Water Regulations
TBCs until Promulgation Date (Expected in March 1992)
Inorganics
Antimony
Beryllium
Cyanide
Nickel
Sutfate
Thallium
Organlcs
Andipates
[Di(ethylhexyl)adipate]
Dalapon
Dichloromethane (methylene
chloride)
Dinoseb
Diguat
Endothall
Endrin
Glyphosate
Hexachlorobenzene
Hexachlorocyclopentadine
(HEX)
Oxamyl (Vydate)
PAHs [Benzo(a)pyrene]
Phthalates
[Di(ethylhexyl)phthalate]
Picloram
Simazine
1 ,2,4-Trichlorobenzene
1,1+2Trichlorethane
2,3.7,8-TCDD (Dioxin)
MCLGs
0.03
00.001
0.2
0.1
400/500
0.0005
0.5
0.2
0
0.007
0.02
0.1
0.002
0.7
0
0.05
0.02
0
0
0.5
0.001
0.009
0.003
0
MCLs
0.01/0.005
0.001
0.2
0.1
400/500
0.002/0.001
0.5
0.2
0.005
0.007
0.02
0.1
0.002
0.7
0.001
0.05
0.02
0.0002
0.004
0.5
0.001
0.009
0.005
5x10(-8)
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