vvEPA
Unrted States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
ARARs Q's & A's:
State Ground-Water
Antidegradation Issues
Office of Emergency and Remedial Response
Office of Program Management OS-240
Publication 9234 2-11/FS
July 1990
Quick Reference Fact Sheet
Section 121(d)(2) of CERCLA, as amended by the 1986 Superfund Amendments and Reauthonzation Act (SARA),
requires that remedial actions must at least attain Federal and more stringent State applicable or relevant and appropriate
requirements (ARARs) upon completion of the remedial action. The 1990 National Contingency Plan (NCP) requires
compliance with ARARs during remedial actions as well as at completion, and mandates attainment of ARARs during
removal actions to the extent practicable. See revised NCP, 40 CFR section 300.435(b)(2) (55 FR 8666, 8852)(March 8,
1990) and section 300 415(i) (55 FR 8666, 8843)(March 8, 1990).
This Q's and A's fact sheet is designed to provide guidance on the status of State ground-water antidegradation
provisions as potential ARARs for CERCLA ground-water and soil remedial actions. The guidance in this fact sheet
reiterates Agency policy already in practice in EPA's Regional offices. The goal and policy of the Superfund program is
to return usable ground water to its beneficial uses within the timeframe that is reasonable, given the particular
circumstances of the site. In addition to our goal of ground-water cleanup, Superfund has a nondegradation policy in that
we strive for the prevention of further degradation of the ground water during our remedial actions. However, it should
be noted that more stringent State standards than those imposed by EPA policy may be imposed by State antidegradation
requirements. Such State requirements, if they have been determined to be ARARs for the site, would have to be met (e.g.,
by meeting the discharge requirements) or waived (e.g., by the interim remedy waiver). Nevertheless, even where temporary
degradation of the ground water may be required during the remedial action, we will provide protection by restricting access
or providing institutional controls, and EPA response actions will ultimately result in restoration of the ground water's
beneficial uses.
(NOTE: States use the terms "nondegradation" and "antidegradation" interchangeably; there does not appear to be
a consistent distinction between the two. As a result, all State nondegradation and antidegradation requirements are
referred to in this fact sheet as antidegradation requirements.)
Ql. What is a State ground-water antidegradation
requirement?
A. State antidegradation requirements vary widely in
their scope and drafting. However, as a general rule,
they are anti-pollution requirements (not cleanup
requirements) designed to prevent degradation of the
surface water or ground water. Antidegradation
requirements typically accomplish their purpose in
one of two ways: (1) by prohibiting or limiting
discharges that potentially degrade the surface water
or ground water (typically action-specific require-
ments); or (2) by requiring maintenance of the
surface-water or ground-water quality consistent with
current uses.
Under the Clean Water Act, every State is required
to classify all of the waters within its boundaries
according to their intended use. As required by EPA
regulation, all States have established surface-water
antidegradation regulations. These requirements may
be potential ARARs for CERCLA remediations in-
volving discharges to surface water. Although not
specifically required by EPA, the majority of States
have also established some form of ground-water
antidegradation provisions. These States may have
enacted specific ground-water antidegradation
statutes, or they may include ground-water protection
provisions within general environmental statutes.
These State provisions for ground water may
constitute potential ARARs for CERCLA remedia-
tions that have an impact upon the ground water
(e.g., ground-water reinjection or soil flushing).
Q2. State antidegradation requirements are often
expressed as general goals. Can they be potential
ARARs?
A. Yes, antidegradation requirements expressed as
general goals may be potential ARARs if they are:
Pnntad sn Recycled Paper
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(1) directive in nature and intent, and (2) established
through a promulgated statute or regulation that is
legally enforceable (see Preamble to the revised NCP
at 55 FR 8746)
Antidegradation provisions are directive in nature
when they contain narrative or numerical limits, or
are implemented by State regulations that provide
needed specificity For example, general anode-
gradation goals are sufficiently directive when
implemented by regulations setting limits that
ground-water contamination may not exceed When
a general State antidegradation statute does not have
any implementing regulations, EPA has considerable
discretion in determining what is required to inter-
pret or comply with the law (see Preamble to the
revised NCP at 55 ER 8746).1 For example, EPA
may look at State surface-water or ground-water use
and classification systems, such as those that set
water-quality standards, since they designate uses of
a given water body and/or maximum concentration
levels to protect those uses. Alternatively, EPA may
look at a State’s wellheaci protection program for
requirements concerning ground-water maintenance.
If the State’s narrative, general antidegradation goals
stand alone, they may be nothing more than
statements of intent about desired outcomes or
conditions Statements of intent are insufficiently
directive to constitute potential ARARs. Likewise,
vague or ambiguous narrative descriptions of ground-
water degradation limits probably do not provide
sufficient direction to constitute potential ARARs
(see Preamble to the revised NCP at 55 FR 8746).
To be considered a potential ARAR, a State anti-
degradation law must be established through a
promulgated statute or regulation that is legally
enforceable and “of general applicability” (see NCP,
section 300.400(g)(4)). To be legally enforceable,
State standards must be requirements -- not guidance
-- that are issued according to the State procedural
requirements and that contain certain specific
enforcement provisions or are otherwise directly
enforceable under State law (see Preamble to the
revised NCP at 55 ER 8746). The phrase “of general
applicability” means that potential State ARARs must
be applicable to all remedial situations described in
the requirement, not just to CERCLA sites (see
Preamble to the revised NCP at 55 ER 8746).
The State may argue that its interpretation of the meaning of the goal,
the Siate’s non-binding guidance, should determine the siatuie’s
caning The Suite may also argue that State courts have upheld the
ate’s interpretation of the requirement If either of these arguments is
used, advice should be soughi from the Office of Regional Counsel
)RC) or the Office of General Counsel (OGC)
Q3. At what point do State ground-water antidegradation
requirements become ARARs at a Superfund site?
A. Antidegradation requirements are generally action-
specific requirements that may apply during the
course of and at the completion of the Agency
response action. They apply prospectively, and
generally obligate the Agency only to prevent further
degradation of the water during and at completion of
the response action (not prior to it). While antt-
degradation requirements are not cleanup laws, in
some limited cases they may, as relevant and appro-
priate requirements, be appropriate for establishing
a cleanup level for past contamination.
Furthermore, EPA is not required to take any
response action unless and until EPA determines
that it iS appropriate to do so. Even then, this action
must meet (or waive) a State requirement only if the
Agency determines that the requirement is an ARAR
for the site The Agency determines what Federal
and State laws constitute ARARs that must be met
or waived during or at the completion of a response
action. Compliance with a specific Federal or State
law is triggered when the Agency determines that a
requirement is either applicable to site remediation,
or relevant and appropriate because its use is well-
suited to site circumstances. However, neither
CERCLA nor the NCP requires the Agency to
comply with ARARs prior to conducting a response
action Therefore, when the Agency decides to take
a response action, and if the Agency determines that
a State antidegradation requirement is an ARAR for
a site, the Agency must meet or waive the
requirement
It should also be noted that only ARARs within the
scope of the response action have to be met or
waived If the Agency is conducting an RI/FS to
determine the action that may be necessaiy at a site,
the State’s ground-water antidegradation require-
ments are generally beyond the scope of the action,
and therefore are not likely to be potential ARARs
for it. Of course, if a proposed RI/FS activity such as
site sampling has the potential to temporarily
degrade the ground water, the specific terms of the
State ground-water antidegradation requirement
should be examined to determine whether it is an
ARAR for that action.
Q4. When are State ground-water antidegradation
requirements likely to be applicable to CERCLA
remediations that affect the ground water? When
they are applicable, what is required for compliance?
A. The attached matrix analyzes whether six hypothetical
State antidegradation requirements for ground water
are ARARs for four different CERCLA remedia-
tions. For most sites, the matrix may be helpful in
determining whether State antidegradation require-
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ments are ARARs for remediations that affect the
ground water. The information in the text of this fact
sheet is provided to give the specific analysis and
rationale underlying the conclusions reached in the
attached matrix. Although only two of the six
hypothetical State antidegradation requirements are
analyzed here in detail, these principles should
generally apply to most State ground-water
antidegradation requirements.
Applicability of State ground-water antidegradation
requirements depends upon three factors:
• The specific language of the State statute or
regulations;
• The nature of the CERCLA remediation; and
• The circumstances at the site.
First, a review of the specific language of the State
statutes (or regulations) reveals that most anti-
degradation requirements fall into one of two cate-
gories: (1) those that focus upon prohibited
discharges; and (2) those that focus upon maintaining
the ground water consistent with its uses. Second,
with respect to the nature of the CERCLA remedia-
tion, there are three forms of remediation that may
trigger ground-water antidegradation requirements:
ground-water pump-and-treat, ground-water natural
attenuation, and soil flushing. Finally, applicability is
affected by the circumstances at the site such as the
contaminant levels of the effluent, and the quality of
the receiving aquifer. The sections that follow pro-
vide hypothetical examples of the applicability of
State ground-water antidegradation requirements.
The examples discuss the applicability of the two
categories of State antidegradation requirements
under the three different remediation scenarios (i.e.,
pump and treat, natural attenuation, and soil
flushing).
[ Note on “current uses” : Some State antidegradation
statutes require maintenance of ground-water quality
consistent with its “current uses.” Where the State
statute (or implementing regulation) has defined
“current uses,” that definition should be considered an
integral part of the requirement that helps determine
whether EPA response actions comply with these
requirements, if they are determined to be ARARs
For example, any State antidegradation statute that
defines “current uses” as “present uses” would be met
at sites where the CERCLA discharge is to an aquifer
that is already contaminated such that it has no
present uses. State antidegradation requirements that
do not define “current uses” will generally be met at
Superfund sites where EPA ground-water or soil
remediation maintains, or does not adversely effect,
the current quality of the aquifer. The following
analysis of antidegradation requirements for main-
taming the ground water is based upon the
assumption that they do not define “current uses.”j
Scenario #1: Pump-and-Treat
Assumption: The ground water is contaminated or, at a
nun iniuni, contains a plume of contamination The
ground water is a Class I or II aquifer (which means
that it is or may be a potential source of drinking
water)
A) State ground-water antidegradation requirements
that prohibit discharges: These are not applicable to
ground-water pump-and-treat remedies if there is no
“discharge,” as defined under the ARAR However,
even if the reinjections associated with each iteration
during pump-and-treat constitute a discharge under
the State statute, the statute is violated only if the
discharge constitutes the type prohibited by the
statute.
Compliance: If, for example, the statute prohibits
discharges that are injurious to public health, the
remedy generally would comply with it where the
receiving aquifer is already contaminated (A dis-
charge of contaminated effluent into a contaminated
aquifer enerally would not be “injurious to public
health.”) Moreover, the discharge, as part of a
contained pump-and-treat system, may not be in-
jurious to public health. LNQi : Since it is EPA’s
goal to restore ground water to its beneficial uses,
the Superfund program would rarely propose a
pump-and-treat remedy that would degrade pristine
or only slightly contaminated water. In those rare
cases where the remedy involves reinjections to a
pristine or only slightly contaminated aquifer, an
interim action waiver might be appropriate.]
B) State antidegradation requirements that require
ground-water maintenance consistent with its
current uses: These generally are applicable to
ground-water pump-and-treat remediations.
Compliance: The remedy generally would comply
with these requirements during pump-and-treat
remediations, if the remedy maintains (i.e., does not
adversely effect) the current quality of the aquifer.
Current quality of the aquifer should generally be
maintained through pump-and-treat for two reasons
(1) pump-and-treat remediation will decrease, not
increase, the contaminant level of the aquifer; and
(2) it serves to contain the contaminated plume.
2 A Stale may argue thai it has interpreted ihe phrase “injunous to public
health” in guidance or policies, or that court decisions have addressed the
issue, and that EPA musi follow that interpretalion If such an argument
is raised, ii must be referred tQ ORC or OGC
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Therefore, if these conditions are satisfied, the
antidegradation provision should be met
(NoteS If pump-and-treat reinjections fail o maintain
the current quality of the aquifer, an interim action
waiver could be invoked, assuming the aquifer will be
suitable for its current use upon completion of the
remediation]
Scenario #2: Natural Attenuation
Assumpi ion: The ground water is contanunated or, as
a nunimuni, contains a plume of contaminanon The
ground water is a Class I or II aquifer (which means
that it is or may be a potential source of drinking
water)
A) State ground-water antidegradation requirements
that prohibit discharges: These are not applicable to
natural attenuation of the ground water because there
is no discharge during natural attenuation.
Compliance: The statute is not applicable to natural
attenuation, but it may be relevant and appropriate
depending upon circumstances at the site (see
Question #5 below)
B) State antidegradation requirements that require
ground-water maintenance consistent with its current
uses. These are potentially applicable to natural
attenuation.
Compliance: The remedy generally would comply
with these requirements during natural attenuation
remediation, if the remedy maintains (i.e., does not
adversely affect) the current quality of the aquifer.
Moreover, it is unlikely that natural attenuation will
interfere with the ground water’s current uses, since
natural attenuation is typically confined to sites where
the contaminant level is low, there are small areas of
contamination, and the plume will not migrate signifi-
cantly. Therefore, natural attenuation generally
should meet this type of antidegradation requirement.
[ NQi : Where such requirements are not met, an
interim action waiver might be appropriate, assuming
the aquifer will be suitable for its current use upon
completion of the remediationj
Here, again, the State may argue thai a more limited definition of
“current uses” is the only valid interpretation If so, consult ORC or OGC
Scenario #3: Soil Flushing
Assumpi ions: The sot! is contaminaseiL Through soil
flushing; contaminated effluent will enter the ground
water and then be extracted for treatment The ground
water is a Class I or II aquifer (which means that it is
or may be a potential source of drinking waler). The
aquifer may or may not be contaminated.
A) State ground-water antidegradation requirements that
prohibit discharges: These are likely to be applicable
because the effluent from the soil flushing probably
constitutes a discharge. However, the statute is
violated only if the discharge constitutes the type
prohibited by the statute.
Compliance: If, for example, the statute prohibits
discharges injurious to public health, EPA may
conclude that soil flushing would comply with it where
the receiving aquifer is already contaminated. (A
discharge of contaminated effluent into a con-
taminated aquifer generally would not be “injurious to
public health.”) Moreover, if pump-and-treat
remediation is conducted concurrently with the soil
flushing, EPA may conclude that the “discharge” is not
injurious to public health because it would be
controlled and contained through the pump-and-treat
remediation. 4
Since it is EPA’s goal to restore ground water
to its beneficial uses, the Superfund program would
rarely propose a soil flushing remedy that would
degrade pristine or only slightly contaminated water.
Thus, the issue of compliance of soil flushing with an
antidegradation standard should rarely be a problem
for Superfund ground-water remediations. In rare
cases where degradation of a pristine aquifer through
soil flushing is necessary, RPMs should invoke the
interim measures ARARs waiver.]
B) State antidegradation requirements that require
ground-water maintenance consistent with its current
uses: These presumably are applicable to soil
flushing.
4
Compliance: The remedy generally would comply with
these requirements during soil flushing, if the remedy
maintains (i.e., does not adversely effect) the current
quality of the aquifer. Current quality of the aquifer
is maintained if the effluent at least meets current
water quality levels of the aquifer. Because soil
flushing is generally only considered for contaminated
aquifers, these requirements typically may be met. 5
Again, the State may argue that a more limited interpretation is
required If so, consult ORC or OGC
State arguments that a more resinctuve Interpretation of the standard
is required should be referred to ORCor OGC.
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Q5. Are State ground-water antidegradation require-
ments likely to be relevant and appropriate re-
(juirements for remediation that affects the ground
water?
A It depends upon whether the requirements are well-
suited for use at the site. While examples are given
below, a more definite answer cannot be given
because relevance and appropriateness is a site-
specific determination. See section 300 400(g)(2) of
the revised NCP (See the attached matrix for
additional examples)
For example, State antidegradation requirements that
are applicable to discharges injurious to public health
are potentially relevant and appropriate to all
ground-water remediations (whether or not there is
a discharge), by prohibiting remediations injurious to
public health These principles, when applied to
CERCLA remediations, should be analyzed as
follows. 6
A) EPA does not consider pump-and-treat remediations
of a contaminated plume to be injurious to public
health because they are generally effective at
containing and treating contaminated plumes (See
OSWER Directive 9355.4-03, October 1989, entitled
“Considerations in Ground-Water Remediation at
Superfund Sites’). Therefore, pump-and-treat
6 The following rcilccis EPA ’s gcneral anaiysis of how severai types of
remedialion shou’d be evaluated The Staie may lake a difrerent and more
limited view of what was intended under ihe statute If the State argues
br a differcni inlerpiciation of its iaws, consult ORC or OUC
remediaiions would generally comply with these
requirements, if relevant and appropriate.
B) Natural attenuation remedtanon would also be
expected to comply with these requirements
prohibiting injurious discharges (if relevant and
appropriate). Examples include sites where: (1) a
contaminated plume is located within a Class III
aquifer; (2) a contaminated plume is moving within
parts of a Class I or II aquifer that are also signi-
ficantly contaminated; or (3) the plume is small, its
contaminant levels are low, and it will not migrate
significantly. Natural attenuation might be said not
to comply with these requirements if it allows a con-
taminated plume to move into a pristine, or only
slightly contaminated portion of a Class I or II
aquifer, the interim action waiver must be invoked at
such sttes, and precautions such as institutional
controls should be taken.
C) Soil flushing generally would comply with these
requirements, if relevant and appropriate, at sites
where the aquifer is already contaminated. Con-
taminants from soil flushing might be said to be
injurious to public health if introduced into a
pristine, or only slightly contaminated portion of a
Class I or II aquifer. In those rare cases where it is
necessary to select this remedy at such sites, the
interim action waiver must be invoked, and
precautions such as institutional controls should be
taken.
highlight I: KEY FACTORS FOR TIlE
APPLICABILITY OF STATE G ROUND-WATER
ANTI I)EGRADATION REQUIREMENTS
TO SOIL FLUShING
• Whether the State statute is triggered because
eiiher the effluent constitutes a ‘discharge” under
the Siaie law, or the State statute requires
ground-water maintenance (during CERCLA
remediation) consistent with current uses,
• Vhcthcr the statute defines ‘current uses” as
present uses or pre-contamination uses;
• Whether the aquifer is pristine, slightly
contaminated, or greatly contaminated;
• Whether the effluent has high contaminant
levels, and,
• Whether soil flushing will be conducted
concurrently with pump-and-treat remediation of
the ground water.
Highlight 2: COMPLIANCE WITH STANDARDS
SET BELOW DETECTiON LEVELS
State ground-water antidegradation standards that
are set below detection levels cannot be measured or
verified, Therefore, if such standards are applicable,
the technical impracticability waiver should generally
be invoked where compliance with such standards is
not possible due to detection limits. Potentially
relevant and appropriate standards that cannot be
measured or verified may not be appropriate and,
therefore, are not ARARs (see Preamble to the
revised NCP, 55 FR 8750-8752).
Regions should not extrapolate from existing data or
technologies to reach a level set below detection
capabilities because such extrapolations cannot be
verified scientifically with any degree of certainty.
Without verification, neither the Agency nor the
potentially responsible parties could legally establish
that cleanup goals were met. Furthermore, the NCP
states that relevant and appropriate requirements
must be measurable and attainable since their pur-
pose is to set a standard that an actual remedy will
attain (see Preamble to the revised NCP, 55
8752).
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Highlight 3: POTENTIAL ARARs WAIVERS FOR
STATE ANTIDEGRADATION REQUIREMENTS
The Interim Measure Waiver : This waiver provides
that the action selected need not attain an ARAR
where the action “is only part of a total remedial
action that will attain such level or standard of
control when completed” See CERCLA section
121(d)(4)(d). Therefore, the interim measures waiver
may be used to waive ARARs for interim measures
which, by their temporary nature, do not attain all
ARARs However, the interim measure must be
followed by, or be part of, complete measures that
attain all ARARs, and it should not exacerbate site
problems nor interfere with the final remedy (see the
revised NCP, 55 FR 8747-8748 (March 8, 1990)).
The Inconsistent Application of State Requirements
Waiver . This waiver is intended to prevent the
application to Superfund sites of State requirements
that have not been consistently applied elsewhere in
a State. State standards are presumed to have been
consistently applied unless there is evidence to the
contrary. When questioned by EPA, States may
provide evidence of consistency of application by
demonstrating: (1) the similarity of sites or response
circumstances; (2) the proportion of noncompliance
cases; (3) reasons for noncompliance; and (4)
intentions to apply future requirements (see the
revised NCP, 55 FR 8749 (March 8, 1990)).
NOTICE The policies set out in this ARARs Q’s and
A’s are intended solely for 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. EPA officials may decide to follow the
guidance provided in this Q’s and A’s, or to act at
variance with the guidance, based on an analysis of
specific site circumstances. The Agency also reserves
the right to change this guidance at any time without
public notice.
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flAIKJJL ANALISJ.b ur bIAIL UKUUDIP-WATLK ANTJ.IThUKM)ATIUfI Kf.QUIKLIthNXS
AS THEY PERTAIN TO CERTAIN REMEDIES AND SITE CIRCUMSTANCES t
REMEDY/SITE CIRCUMSTANCES
SOIL Ra IEDIATION:
SOIL RDIEDIATION:
GROUND-WATER RthEDIATION:
GROUND-WATER R}]IEDIATION:
SOIL FLUSHING
SOIL FLUSHING
PUMP AND TREAT
NATURAL ATTENUATION
(Where the Aquifer May or
May
(Where the Aquifer May or
May
(Aquifer With a Contaminated
(Aquifer With a Contaminated
Not Be Contaminated
--
Not Be Contaminated
STATE LAW Moving Plume)
Moving Plume)
Followed by Pump and Treat)
Concurrent With Pump and
Treat)
The ground water
must be protected.
Discharges that are
injurious to pubLic
health are pro-
hibited.
EAR:” ground-water
rasediations that
are injurious to
public health are
prohibited. This
may arguably occur
if a ramediation
allows a contami-
nated plume to muve.
2. The ground water
must he protected.
No discharge is
permitted unless a
State Board issues a
permit.
RAR: ground—water
rasediations must
protect the ground
water consistent
with State permit
standards (which
may, for exsmple,
prohthit the
introduction of
contaminants into a
portion of an
aquifer used for
drinking).
• Not applicable if there is no
discharge If each reinjec—
tion is s “discharge, the
requirement is nat if the
discharge is not ‘injurious
to public health (a g
where the receiving aquifer
is slresdy contaminated, or
if the reinjoction has low
contaminant levels) It is
generally not a RAR if the
plume is moving into parts of
the aquifer that are also
significantly contaminated
If it is a EAR, and it re-
quires some degree of plume
containment, we comply with
it through pump and treat
• Permits are not required (aea
CERCLA SlZl(e)(l)) Substan-
tive requirements of the per-
mit program are not appli-
cable if there is no dis-
charge If each reinjaction
constitutes a “discharge,”
the raquiranent is net if
each reinj action meets the
substantive requirements of
the permitting regulations
(a g , no “harmful dis-
charge) It is generally not
a EAR if the plume is moving
to parts of the aquifer that
are also significantly con-
taminated If it is a RAR,
and it requires some degree
of plume containment, we
comply with it through pump
and treat
• Not applicable because there
is no diacharge It is gen-
erally not a EAR if the plume
is moving to parts of the
aquifer that are also signi-
ficantly contaminated If it
ia a EAR, and it requirea some
degree of pluma containment,
we comply with it by limiting
natural attenuation to sites
where the plume will not mi-
grate to the portions of the
aquifer used for drinking and
contaminant levels are low,
thereby preventing injury to
public health Otherwise, we
may use the interim action
waiver, usually accompanied by
inatitutional controla
• Permits are not required (see
CERCLA §lZl(e)(l)) Substan-
tive requirements of the per-
mit program are not applicable
because there is no dis-
charge It is generally not a
EAR if the plume is moving to
parts of the aquifer that are
also significantly contami-
nated If it is a EAR, and it
requires some degree of plume
containment, we may comply
with it by limiting natural
attenuation to sites where the
plume will not migrate into
portions of the aquifer desig-
nated for drinking or other
protected uses Otherwise, we
may use the interim action
waiver, usually accompanied by
institutional controls
• May be a discharge, however,
the requirement is met if the
discharge is not injurious to
public health Ce g , because
the aquifer already exceeds
health-based levels or if the
discharge has low contaminant
levels) If discharging to a
pristine or slightly contam-
inated aquifer, we may use
the interim action waiver
• May be a discharge, however,
no permits are required under
CERCLA $l2l(eXl) If the
substantive requirements of
the permit program are AR.ARe,
the action may comply if the
contaminant levels of the
effluent entering the ground
water do not exceed the
discharge standards set in
the ROD (based on State
permit requirements) Other-
wise, we may use the interim
action waiver
• May be a discharge, however,
the requirement is met if the
discharge is not injurious to
public health Ce g , because
the aquifer already exceeds
health—based levels or if the
discharge has low contaminant
levels) If it is an ARAR, we
may comply with it by conduct-
ing pump end treat sirmilta-
neously, if the discharge (as
it is part of a contained
treatment system) is not injur-
ious to public health Other-
wise, we may use the interim
action waiver
• May be e discharge, however, no
permits are required under
CERCLA Sl2l(e)(l) If the
substantive requirements of the
permit program are ARARs, the
action may comply if the
contaminant levels of the
effluent entering the ground
water do not exceed the
discharge standards set in the
ROD (based on State permit
requirements) Otherwise, we
may use the interim action
waiver
This matrix provides general considerations only.
Consult with ORC or OGC on specific applications.
-1-
Relevant and Appropriate Requirament
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MATRIX ANALYSIS OF STATE GROUND-WATER ANTIDEGRADATION REQUIREMENTS
AS THEY PERTAIN TO CERTAIN REMEDIES AND SITE CIRCUMSTANCES t
REMEDY/SITE CIRCUMSTANCES
SOIL RDIEDIATION
SOIL RDIEDIATION:
GIOUND-W aTifit R}flDIATION:
GIOUND-W&TER
RDIEDIATION;
SOIL FLUSHING
SOIL FLUSHING
PUMP AND TREAT
NATURAL ATTENUATION
(Where the Aquifer May or
May
(Where the Aquifer May or
May
(Aquifer With a Contaminated
(Aquifer With
a Contaminated
Not Be Contaminated
--
Not Be Contaminated
--
STATE LAW Moving Plume)
Moving
Plume)
Followed by Pump and Treat)
Concurrent With Pump and
Treat)
3. The ground water
must be protected.
No discharge ia
permitted to a
usable aquifer.
RAR;” ground-water
ranediationa that do
not protect a usable
aquifer are pro—
h.ibited. This may
occur if the ramedi—
ation allows a con-
taminated plume to
move.
• Requirement ia not applicable
if there is no discharge If
each reinjection constitutes
a “discharge.” the require-
ment is not applicable if the
prior contamination already
rendered the aquifer un-
usable The requirement is
not a RAR if the plume has
rendered the aquifer unusable
or if the plume is moving to
parts of the aquifer that are
also significantly contami-
nated If it is a RAR, and
it requires some degree of
plume containment, we comply
with it through pump and
treat
• Requirement is not applicable
because there is no discharge
Also, the requirement is not
applicable if the plume has
rendered the aquifer unusable
The requirement may not be a
RAR if the plume has rendered
the aquifer unusable or if the
plume is moving to parts of
the aquifer already contami-
nated If it is eRAR, and it
requires some degree of plume
containment, we may comply
with it by limiting natural
attenuation to sites where the
plume will not migrate to
usable portions of the aqui-
fer Otherwise, we may use
the interim action waiver,
usually accompanied by insti-
tutional controls
• May be a discharge, however,
the requirement is not appli-
cable if the aquifer is not
usable Ce g , because it is
already contaminated) This
requirement is probably ap-
plicable if the aquifer is
pristine or slightly contam-
inated If so, we may use
the interim action waiver
• May be a discharge, however,
the requirement is not appli-
cable if the squifer is not
usable Ce g , because it is al-
ready contaminated) If it is
an ARAR, we may comply with it
by simultaneously conducting
pump and treat if the prompt
containment and treatment of
contaminants protects usable
portions of the quifer
Otherwise, we may use the
interim action waiver
4. The ground water
saint be protected.
No discharge is
permitted if it
interferes with
existing uses.
RAR:” ground-water
rasedintions that
interfere with
existing or
potential uses are
prohibited. This
nay occur if the
ramedietion allows a
contaminated plume
to move.
• Requirement is not applicable
if there is no dischmrge If
each rein,jection constitutes
s “discharge,” the require-
ment is met if the existing
uses(/quslity) of the aqui-
fer is maintained Ce g
where the aquifer is already
contaminated) It would
generally not be a RAR if the
plume is moving to a portion
of the aquifer that is al-
ready contaminated If it is
a RAR, it requires some
degree of plume containment,
we comply with it through
pump and treat
• Requirement is not applicable
because there is no discharge
It would generally not be a
RAR if the plume is moving to
a portion of the aquifer that
is already contaminated If
it is e RAR, and it requires
some degree of plume contain-
ment, we may comply with it by
limiting natural attenuation
to sites where contaminant
levels are low and any plume
migration will not affect the
existing uses(/quslity) of the
aquifer Otherwise, we may
use the interim action waiver,
usually accompanied by insti-
tutional controls
-2-
• May be a discharge, however,
the requirement is not appli-
cable if the existing uses
C/quality) of the aquifer is
maintained Ce g , where the
aquifer is already contami-
nated) This requirement is
probably applicable if the
aquifer is pristine or
slightly contaminated If so,
we may use the interim action
waiver
• May be a discharge, however,
the requirement is not appli-
cable if the existing uses
C/quality) of the aquifer is
maintained Ce g , where the
aquifer is already contami-
nated) This requirement is
probably applicable if the
aquifer is pristine or slightly
contaminated If so, we say
use the interis action waiver
This matrix provides general considerations only.
r,, .,at i.i. vtr rvr n,l4rot1n,,..
Relevant and Appropriate Requirament
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MATRIX ANALYSIS OF STATE GROUND-WATER ANTIDEGRADATION REQUIREMENTS
AS THEY PERTAIN TO CERTAIN REMEDIES AND SITE CIRCUMSTANCES*
REMEDY/SITE CIRCUMSTANCES
SOIL RD IATION:
SOIL RD SHIATION:
ND-WAT R IATIC :
UND-WAT
R IATION:
SOIL FLUSHING
SOIL FLUSHING
PUMP AND TREAT
NATURAL ATThNIJATIOII
(Where the Aquifer May or
Hay
(Where the Aquifer May or
May
(Aquifer With a Contaminated
(Aquifer With
a Cont,aminated
Not. Be Contaminated
-
Not Be Contaminated
--
STATE LAW Having Plume)
Having
Plume)
Followed by Pump and Treat)
Concurrent With Pump and
Treat)
5. Maintain ground
water at existing
high quality unless
the State Board
approves the change
to the water qual-
ity. IStatute
requires ground-
water maintenance at
existing high
quality during
remediatton. This
may require
conteiament. of a
contaminated moving
plume.]
RAR: same as
applicable.
• Requirement is not applicable
if the ground water is not. of
high quality due to the con-
teminated plume. This re-
quirement may be applicable
if the aquifer is pristine or
only slightly contaminated
If so, we nay use the interim
action waiver. It may be a
EAR if the plume is moving to
portions of the aquifer that
are designated for drinking
or other protected uses. If
the requirement Is a EAR, end
it requires some degree of
plume containment, we comply
with it through pump and
treat
• Requirement is not applicable
if the ground water is not of
high quality due to the con-
taminated plume If the re-
quirement is a EAR, we nay
comply with It by limiting
natural attenuation to sites
where the plume contaminant
levels are low end the plume
will not migrate signifi-
cantly Otherwise, we may use
the interim action waiver,
usually accompanied by insti-
tutional controls.
• Requirement is not applicable
if the ground water is al-
ready contaminated This re-
quirement may be applicable
if the aquifer is pristine or
Only slightly contaminated
If so, we may use the interim
action waiver.
• Requirement is not applicabLe
if the ground water is already
contaminated This requirement
may be applicable if the aq1J -
far is pristine or only slight-
Ly contaminated If so, we may
use the interim action waiver
6. Ground-water quality
most be maintained
c naurate with
current uses.
Statute requires
maintenance of
ground-water quality
during remediation.
This may require
contaimoent of a
contaminated moving
plume.
RAR:” same as
applicable.
• Requirement is presumably
applicable Requirement is
met if the remedy maintains
the current quality of the
aquifer (e g , where the re-
injections at least meet
current water uses(/quality)
levels of the aquifer) If
the requirement is an ARAR
end it requires some degree
of plume containment, we
comply with it through pump
and treat.
• Requirement is presumably
applicable Requirement is
met if the remedy maintaina
the current uses(/quality) of
the aquifer (e.g. where plume
contaminant levels are low,
there are small areas of
contamination, and the plume
wilL not migrate signifi-
cantly) Otherwise, we may
use the interim action waiver,
usually accompanied by insti-
tutional controls.
-3-
• Requirement is presumably
applicable Requirement is
met if the remedy maintains
the current uaes(/quality) of
the aquifer (e.g , where the
effluent at least meets the
current water quality levels
of the aquifer). Otherwise,
we may use the interim action
waiver
• Requirement is presumably ap-
plicable Requirement is met
If the remedy maintains the
current uses(/quality) of the
aquifer (e g , where the
effluent at least meets the
current water quality levels of
the aquifer) Otherwise, we
may use the interim action
waiver
This matzi.x provides general conaideratiema only.
Consult with or OGC am specific applications.
Relevant and Appropriate Requir t
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