United States Office of EPA530-D-00-001
Environmental Protection Agency Solid Waste April 2000 Draft
http://www.epa.gov/correctiveaction
HANDBOOK OF GROUND WATER
POLICIES FOR
RCRA CORRECTIVE ACTION
(updated 4/20/2000)
for Facilities Subject to Corrective Action Under
Subtitle C of the
Resource Conservation and Recovery Act
Issued by
Office of Solid Waste
Corrective Action Programs Branch
Note: This document provides guidance to EPA and states regarding groundwater at facilities subject to RCRA
Corrective Action. It also provides guidance to the public and the regulated community on how EPA intends to
exercise its discretion in implementing its statutory authorities and regulations. The document does not, however,
substitute for EPA's statutes or regulations, nor is it regulation itself. Thus, it cannot impose legally-binding
requirements on EPA, States or the regulated community, and may not apply to a particular situation based upon
the circumstances. EPA may change this guidance in the future as appropriate.
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Handbook Overview
What does this Handbook do?
Who should use this Handbook?
How will it help me?
How will I know this Handbook is current?
If you are viewing an electronic version,
you can hit the button to take you to the topic of interest
Future Policy?
Completing
Ground water
Remedies
Performance
Monitoring
Injection of
Contaminated
Ground water
Technical
Impracticability
Short Term
Protectiveness Goals
including
Environmental Indicators
References
Final Remediation
Goals
Ground water
Use
Designation
Monitored
Natural
Attenuation
Glossary
Ground water Cleanup
Objectives
Ground water
Cleanup Levels
Point of
Compliance
Remediation
Time Frames
Key Contacts
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Table of Contents
Overview 1
What does this Handbook do? 1
Who should use this Handbook? 2
How will this Handbook help me? 2
How do these policies apply to States authorized to implement the RCRA Corrective Action
Program? 2
What topics does this Handbook discuss? 3
Where do the policies in this Handbook come from? 4
Are the policies for RCRA Corrective action contained in this Handbook consistent with the
Superfund cleanup program? 5
How will I know that the policies in this Handbook are current? 5
How can I get further information about the policies in this Handbook? 5
Groundwater Use Designations 7
What is a groundwater use designation? 7
How can groundwater use designations enhance flexibility for RCRA cleanups? 7
How does EPA's policy on groundwater use affect States which consider all of their
groundwater to be a potential drinking water supply? 8
Who makes groundwater use designations? 9
What are EPA's guidelines for making groundwater use designations? 1_0
Short-Term Protectiveness Goals 11
What are EPA's short-term protective ness goals for groundwater? H
How do facilities achieve these goals? H
How does EPA know when facilities achieve these goals? H
How does a facility achieve an Environmental Indicator? V2
Who determines when a facility achieves an Environmental Indicator goal? V2
Does a facility need to perform additional investigation or cleanup, once the facility
achieves the environmental indicators? V2
How do I consider groundwater use in evaluating "Current Human Exposures Under Control?" V2
How do I consider groundwater use in evaluating the "Migration of Contaminated
Groundwater Under Control?" V2
Can a facility achieve the "Migration of Contaminated Groundwater Under Control" when
groundwater discharges to surface water? 1_3
Final Remediation Goals u
What are EPA's final remediation goals for groundwater? 14
How does groundwater use affect the final remediation goal? 15
Groundwater Cleanup Objectives ie
What are groundwater cleanup objectives? 1§
Who specifies groundwater cleanup objectives? 1§
How do groundwater use designations affect groundwater cleanup objectives? 1§
What is the role of groundwater use in developing facility-specific groundwater cleanup
objectives? J7_
Groundwater Cleanup Levels is
What are groundwater cleanup levels? 1J5
How should groundwater cleanup levels be developed? 1J5
What is the role of groundwater use in setting cleanup levels? 19
What is the cleanup level if no one is drinking the groundwater? 1JJ
What is the cleanup level if the groundwater use is designated as non-drinking water? 1JJ
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Are there any situations where the levels described above might not be appropriate? 20
Are there any situations where I don't need to set a groundwater cleanup level? 20
Do alternate concentration limits apply to setting groundwater cleanup levels for facility-wide
corrective action? 21
What are my cleanup levels for groundwater if I am clean closing a RCRA regulated unit? ... 21
Point of Compliance 23
What is the groundwater point of compliance for RCRA Corrective Action? 23
What is the point of compliance when a facility has more than one source of groundwater
contamination? 23
How does a technical impracticability determination affect the point of compliance? 24
What is the role of groundwater use in establishing a point of compliance for groundwater? . . 24
Remediation Time Frame 25
What is the remediation time frame? 25
What is the role of groundwater use in determining remediation time frames? 25
In what types of situations might specific remediation time frames not be defined? 25
Source Control 26
What does source control mean? 26
What are sources of contamination? 26
What are EPA's general expectations for source control regarding groundwater? 26
When should I consider source control measures? 26
When can I contain the sources rather than treat them? 27
How does groundwater use affect source control? 27
Why should I control sources when I've already achieved Environmental Indicators? 27
Monitored Natural Attenuation 29
What is monitored natural attenuation? 29
When is monitored natural attenuation a likely cleanup option? 29
Is monitored natural attenuation acceptable when contaminated groundwater is off-site? .... 29
How long should a facility monitor a Monitored Natural Attenuation Remedy? 30
How does groundwater use influence a monitored natural attenuation remedy? 30
Technical Impracticability H
What does technical impracticability mean? 31
What are the primary causes that might lead to a technical impracticability determination? . . 3J.
Is the mere presence of non-aqueous phase liquids (NAPLs) sufficient to justify a technical
impracticability determination? 3J.
When should a facility recommend Technical Impracticability? 32
Who decides whether cleanup of the groundwater is technically impracticable? 32
What should facilities include in a technical impracticability demonstration? 32
If I get a technical impracticability determination, have I completed corrective action for
groundwater? 32
How much facility investigation do I have to conduct within the technical impracticability zone?33
Why should I control sources within the technical impracticability zone? 33
How does a technical impracticability determination affect the point of compliance? 33
How long should a technical impracticability determination last? 33
How does groundwater use affect a Technical Impracticability determination? 34
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Injection of Contaminated Groundwater 35
Can I inject groundwaterthat is contaminated with hazardous wastes back in the
subsurface as part of corrective action? 35
What are the specific conditions I have to meet prior to injecting groundwater contaminated
with hazardous waste into the subsurface? 35
Can treatment prior to injection include adding nutrients or other products to the contaminated
groundwater designed to promote in-situ bioremediation or other in-situ treatment? . . 35
What is the role of groundwater use with regard to this groundwater injection policy? 36
What if I want to inject groundwaterthat is contaminated with non-hazardous wastes as
part of my RCRA corrective action? 36
Performance Monitoring 37
Why do facilities need to conduct performance monitoring? 37
What should the performance monitoring accomplish? 37
What should a performance monitoring program include? 37
How often should facilities monitor? 37
How do I decide a remedy is working? 38
How long should performance monitoring continue? 38
What is the role of groundwater use in long-term performance monitoring? 38
Completing Groundwater Remedies 39
When does EPA consider groundwater remediation to be complete? 39
What documentation do I need? 39
What is the role of groundwater use in demonstrating completion? 39
References 40
Appendix 1 - How is the RCRA Corrective Action Program Implemented? 43
Appendix 2 - Glossary 44
Appendix 3 - Key EPA Regional Contacts and Internet Addresses 46
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Overview
What does this Handbook do?
This Handbook is designed to help you as a regulator, member of the regulated community or
the public to find and understand EPA policies on groundwater use and the protection and
clean up of groundwater at Resource Conservation and Recovery Act (RCRA) corrective
action facilities. This Handbook is also
designed to encourage individual states to take
a lead role in protecting their groundwater
resources, thus preserving the national interest
in this vital resource.
EPA wrote this Handbook to put together in a
single document EPA's current policies
concerning groundwater at facilities subject to
corrective action under Subtitle C of RCRA1 .
This Handbook is one part of the RCRA
Cleanup Reforms (refer to
http://wvwv.epa.gov/reg5oopa/rcraca/rcra-refor
) that EPA announced on July 8, 1999.
The objective of the Reforms is to promote
faster, focused, and more flexible cleanups2.
EPA's goal for this Handbook is to reduce time-
consuming uncertainties and confusion about
EPA's policies concerning groundwater
protection and cleanup. This Handbook also
emphasizes flexibility in EPA's policies by
describing how current and reasonably
expected future groundwater use should be
considered in the protection and cleanup of
groundwater.
Why is groundwater
important?
Groundwater is the source of about 40% of
the water used for drinking water in the
United States. It provides drinking water for
more than 97% of the rural population who
do not have access to public water-supply
systems. Between 30% and 40% of the
water used for agriculture comes from
groundwater. Withdrawals of groundwater
are expected to rise in the coming century
as the population increases and available
sites for surface reservoirs become more
limited. Groundwater is also critical
because it supplies roughly 40% of the
average annual flow in United States
surface water bodies; these surface water
bodies provide the balance of drinking
water to those areas that do not rely on
groundwater as their primary source for
drinking water.
and EPA, 1999c)
This Handbook contains policies. Unlike
regulations, recommendations contained in
policies are not enforceable requirements unless they are incorporated into a permit or order.
EPA is issuing this Handbook to communicate what EPA believes should generally occur at
RCRA facilities to protect human health and the
1 RCRA primarily addresses three areas - solid waste, hazardous waste, and underground
storage tanks. The Subtitle C program governs the management of hazardous waste (for more
information, see see RCRA Orientation Manual available at
http://www.epa.Qov/epaoswer/Qeneral/orientat/index.htm).
2 The term "cleanup" or the phrase "cleaning up" refers to the range of activities that could occur
in the context of addressing environmental contamination at RCRA facilities. For example, cleanup
activities could include removing waste or contaminated media (e.g., excavation, pumping groundwater,
etc.), in-place treatment of the waste or contaminated media (e.g., bioremediation), containment of the
waste or contaminated media (e.g., barrier walls, low-permeable covers, liners, etc.), or various
combinations of these approaches. The term "cleanup" is often used interchangeably with the term
"remediate" or "remediation."
Draft Handbook of RCRA Groundwater Policies, Page 1
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environment. Therefore, these policies could help facilities currently undergoing RCRA
corrective action. In addition, EPA advises facilities that intend to begin cleanup in advance of
specific direction under a RCRA authority to consult these policies as well.
Who should use this Handbook?
This Handbook is designed to help anyone wanting to better understand EPA's groundwater
cleanup policies at RCRA facilities. We wrote this Handbook for State and EPA regulators,
owners and operators of facilities subject to RCRA Corrective Action, and members of the
public. Throughout the rest of this Handbook we will refer to these three groups as regulators,
facilities, and the public, respectively. Sometimes, we will refer to all three groups collectively
as "stakeholders."
How will this Handbook help me?
If you are a regulator, the Handbook can help clarify key groundwater-related policies which
you should use, where appropriate, to manage investigations and cleanups at your assigned
facilities (via permits, orders or voluntary actions). EPA encourages you to use this Handbook
to do your part in promoting a technically sound, reasonable, and consistent approach to
protecting and cleaning up our nation's groundwater.
If you represent a facility, the Handbook can help you reduce your uncertainties about the
actions a regulator will likely require you to do. This Handbook can also help you in your
financial planning. Clarity in EPA's general expectations will allow you to phase your
investigation and remediation strategy in a manner consistent with the RCRA Corrective Action
Program priorities.
If you are a member of the public, this Handbook can help you understand what EPA generally
expects regulators and facilities to do during an investigation and cleanup of contaminated
groundwater at a RCRA facility. EPA encourages you to use this Handbook as a tool in your
interaction with regulators or facilities. In essence, EPA wrote this Handbook to help you
influence decisions related to groundwater at RCRA corrective action facilities.
If you are relatively new to RCRA corrective action, you can learn more about how EPA and
states implement the program by referring to Appendix 1 of this Handbook and reading the
History of Corrective Action Fact sheet available at www. .
How do these policies apply to States authorized to implement the RCRA
Corrective Action Program?
As of the most recent update of this Handbook, EPA has authorized 33 states and territories to
implement facility-wide corrective action through their state hazardous waste programs in lieu
of EPA. EPA refers to those states as "authorized" for RCRA corrective action. EPA's
authorization of a state corrective action program is based on an evaluation that the state is
capable of implementing corrective action equivalently to EPA, and in a manner consistent with
applicable federal statutes, regulations and guidance. EPA expects these authorized states to
have the primary responsibility for corrective action at hazardous waste treatment, storage and
disposal facilities (TSDFs) in lieu of EPA, which includes making decisions dealing with the
policies in this Handbook. As such, EPA also expects that states will consider this guidance
carefully in implementing their authorized programs. Also, as allowed for by the federal RCRA
statute, states could take an approach that is more stringent than how EPA would implement
Draft Handbook of RCRA Groundwater Policies, Page 2
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the program. Therefore, it is important that Handbook users consult with the state cleanup
program prior to conducting corrective action.
What topics does this Handbook discuss?
EPA selected the topics in this Handbook because they are very often the subject of questions
and some confusion. The topics addressed in this Handbook apply to facilities undergoing
facility-wide corrective action under the
Hazardous and Solid Waste Amendments to
RCRA. In addition, the policy on groundwater
cleanup levels answers some questions
unique to corrective action at RCRA regulated
units3. Users of this Handbook should be
aware that EPA specifies groundwater
monitoring and corrective action requirements
for RCRA regulated units in 40 CFR 264,
Subpart F.4
The first topic "Groundwater Use Designation"
serves as the foundation for the rest of the
Handbook; this topic also includes a detailed
discussion of EPA's expectations regarding
the factors States should consider in making
groundwater use designations. While some of
the other topics deal with broader issues, this
Handbook focuses on groundwater. For
example, the point of compliance policy only
discusses groundwater even though EPA has
guidance for the point of compliance in other
media.
Note that key topics mentioned within the text
are underlined and "hyperlinked". This feature
allows you to recognize topics that are
expanded elsewhere in the Handbook, and allow you to quickly go to that topic should you
desire.
TOPICS PRESENTED"
Groundwater Use Designation
Short-Term Protective ness Goals
Final Remediation Goals
Groundwater Cleanup Objectives
Groundwater Cleanup Levels
Point of Compliance
Remediation Time Frames
Source Control
Monitored Natural Attenuation
Technical Impracticability
Performance Monitoring
Injection of Contaminated Groundwater
Completing Groundwater Remedies
* See below discussion .(Q.r..c.|.ic.k...h.e.re). to see
how EPA intends keep this Handbook
current.
3 Regulated Units are defined in 40 CFR 264.90 as surface impoundments, waste piles, land treatment
units, and landfills that received hazardous wastes after July 26, 1982.
4 A recent rulemaking (Post-Closure Regulations , 63 FR 56710, October 22, 1999) would provide
flexibility to states, which become authorized for the rule (or parts of the rule), to allow alternative requirements for
groundwater monitoring and corrective action for releases to groundwater if (1) the regulated unit is situated among
solid waste management units (SWMUs) or areas of concern (AOCs) that appear to have contributed to the same
release and (2) the alternative requirements will protect human health and the environment (see 264.90(f)). EPA
encourages states to adopt and seek authorization for this provision, either separately or as part of the full post-
closure rule. Pending authorization for this portion of the post-closure rule, states authorized for corrective action
would be able to implement the provision if they could do so as a matter of state law, and they implemented it in a
way that was no less stringent than federal requirements. For more detail on authorization for the post-closure rule
see the preamble to the rule. The Post-Closure regulation, including the preamble is available at
http://www.epa.qov/fedrgstr/EPA-WASTE/1998/October/Day-22/f28221.pdf .
Draft Handbook of RCRA Groundwater Policies, Page 3
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Where do the policies in this Handbook come from?
Each topic in this Handbook is already addressed in an EPA guidance document, directive or
memorandum. This Handbook serves to summarize our current guidance and
recommendations, and provides further clarification of EPA's policies. Many of the policies
come from the the Advanced Notice of Proposed Rulemaking ("ANPR"), May 1, 1996
(http://www.epa.gov/docs/fedrqstr/EPA-WASTE/1996/IVlav/Dav-01/pr-547.pdf). EPA issued
the ANPR based on the expectation that detailed procedural and substantive requirements,
outlined in proposed regulations for corrective action (Subpart S, July 27 1990), would become
final. However, in response to comments on the ANPR, EPA opted against finalizing these
regulations because the Agency decided it was not necessary for successful implementation of
the program. In fact, since a majority (33) of the states and territories were already authorized
to implement facility-wide corrective action in lieu of EPA, and several others were seeking
authorization, EPA decided that promulgating corrective action regulations would be
unnecessarily disruptive. In an October 7, 1999 Federal Register Notice, EPA announced its
withdrawal of most of the provisions of corrective action regulations. In this notice, EPA stated
that rather than issuing a rule to achieve consistency at all facilities, we believe it would be
more appropriate to develop guidance and training to promote consistency, where appropriate.
This Handbook is an example of such guidance. The October 7, 1999 notice also recognized
that the ANPR should serve as the primary corrective action implementation guidance. For
that reason, the ANPR, especially Section III, of the ANPR, is a key reference for many of the
topics in this Handbook. Section IV of the ANPR requested comments on a number of topics
addressed in this Handbook, such as the point of compliance. This Handbook does not
foreclose further discussion of issues raised for comment in the ANPR, and EPA intends to
update this Handbook as the Corrective Action program continues to evolve.
You may notice that the choice of words to describe a policy in this Handbook may differ from
the words in the ANPR or original source of the policy. There are two primary reasons for this
difference. First, we wrote this document in "plain language" and second, the terminology in
RCRA is evolving.
In a June 1, 1998 memorandum (Mtpj//iwwjiP^
President Clinton directed federal agencies to write all new documents in plain language.
Plain language uses everyday words, active voice and shorter sentences. This style makes
documents easier to read and more understandable to the public. However, it may appear at
times that EPA has changed its position on a topic, because EPA selected different words, but
in fact the policy is the same. For example, the Handbook lists several factors for assessing
use, value and vulnerability of groundwater. These factors are the same factors as those
listed in the Comprehensive State Groundwater Protection Program ("CSGWPP") Guidance
(1997), except we modified the words to meet the goals of plain language.
Another source of perceived change stems from the maturing of RCRA Corrective Action
terminology. As the program has evolved, so have RCRA definitions. For example RCRA's
early guidance, proposed Subpart S, referred to achievement of "media cleanup standards" as
a criterion for remedy selection. However, it also used that term interchangably with "media
cleanup levels." The Advanced Notice or Proposed Rulemaking later clarified that the remedy
selection criterion "media cleanup standard" is broader than just the contaminant levels, but
also includes where you measure the levels, "point of compliance," and the time frame to
achieve the levels, "remediation time frame." To capture this broader interpretation, EPA
replaced the term "media cleanup standards" with "media cleanup objectives," and
distinguished "media cleanup levels" as one component of the "media cleanup objectives."
Draft Handbook of RCRA Groundwater Policies, Page 4
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Generally, this Handbook uses the most current term. If you are uncertain of a term's
meaning, you should refer to the glossary in Appendix 2.
Are the policies for RCRA Corrective action contained in this Handbook
consistent with the Superfund cleanup program?
The basic approaches described in this Handbook for groundwater cleanup and the remedial
goals it promotes are the same as those under Superfund. Much of the Handbook is derived
from guidiances developed jointly by EPA's cleanup programs (e.g., Use of Monitored Natural
Attenuation at Superfund, RCRA and Underground Storage Tank Sites). This Handbook,
therefore, is consistent with EPA's long-standing goal for EPA's cleanup programs to yield
similar remedies in similar circumstances. To learn more about RCRA-CERCLA coordination
issues, you should refer to, "Coordination between RCRA Corrective Action and Closure and
CERCLA Site Activities" (EPA, 1996b) available at
and the RCRA-CERCLA deferral policy found
in 54 FR 41004-41006 (October 4, 1989b).
EPA developed this Handbook specifically for RCRA corrective action. Consequently, it differs
in certain minor respects from analogous Superfund guidance because of differences in
program priorities, terminology, and legal authority. For example, a RCRA Facility Investigation
is virtually analogous to a Superfund Remedial Investigation; however, this Handbook uses
RCRA terms. For more information regarding Superfund terms and Superfund policies
pertaining to groundwater, you should refer to "Rules of Thumb for Superfund Remedy
Selection" which is available at .
How will I know that the policies in this Handbook are current?
EPA intends to update this Handbook as necessary to add new topics, new policies, or to
change or clarify existing policies. Therefore, if you are reading a printed copy of this
Handbook, we urge you to access the electronic version available via the Internet at www.
which EPA will keep up to date. The front page of the Internet version will indicate the most
recent date EPA revised the Handbook (e.g., Updated "). Additionally, the top of
each policy includes the date of the most recent revision. You should compare this date to the
Internet version to ensure that you are reading the Agency's most current statements on the
particular topic. Updates to the Internet verison of the guidance will be based on written
updates that are signed by appropriate EPA management and maintained in a hard-copy file.
How can I get further information about the policies in this Handbook?
You can get further information on policies in this Handbook in one of two ways. First, you
could refer to the references provided at the end of the discussion of each policy; a complete
list of all the references is also found at the end of the Handbook. Note that most references
provide a Internet Web address and a "hotlink" which allows you to directly access the
document of interest. Second, you could get more information by contacting one of the "Key
EPA Regional Contacts" that are provided in Appendix 3 of this Handbook. These contacts will
be updated periodically to make sure they are still available for questions concerning
groundwater policy issues for RCRA corrective action.
Draft Handbook of RCRA Groundwater Policies, Page 5
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Key References:
EPA, 1999b. Corrective for Solid Waste Management Units at Hazardous Waste Management
Facilities (64 FR 54604, October 7). Available at
http://www.epa.gov/epaoswer/hazwaste/ca/partwith.htm.
EPA, 1999c. Safe Drinking Water Act, Section 1429 Groundwater Report to Congress. EPA-
816-R-99-016; October, 1999. Available at .
EPA, 1999d. RCRA Cleanup Reforms (EPA530-F-99-018). For more information, refer to
http://wvwv.epa.gov/reg5oopa/rcraca/rcra-reform.pdf.
EPA, 1998a. RCRA Orientation Manual (EPA530-R-98-004). Available at
http://www.epa.gov/epaoswer/general/orientat/index.htm .
EPA, 1998b. Plain Language in Government Writing (June 1). Available at
http://www.npr.gov/librarv/direct/memos/memoeng.html.
EPA, 1998d. Standards Applicable to Owners and Operators of Closed and Closing
Hazardous Waste Management Facilities: Post-Closure Permit Requirement
and Closure Process; Final Rule (63 FR 56710). Available at
.
EPA, 1997a. Memorandum from Elliott P. Laws and Steven A. Herman to RCRA/CERCLA
Senior Policy Managers titled, "Use of the Corrective Action Advance Notice of Proposed
Rulemaking as Guidance" (January 17). Available at www. .
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
. Particularly
relevant pages: 19448-52.
EPA, 1996b. Memorandum from Steven A. Herman and Elliott P. Laws to RCRA/CERCLA
Senior Policy Managers titled, "Coordination between RCRA Corrective Action and Closure
and CERCLA Site Activities" (September 24). Available at
http://www.epa.gov/swerffrr/doc/924memo.htm.
EPA, 1989b. National Priorities List for Uncontrolled Hazardous Waste Sites - Final Rule
Covering Sites Subject to the Subtitle C Corrective Action Authorities of the Resource
Conservation and Recovery Act (commonly referred to as the RCRA Deferral Policy).
Available in Section V which appears on 54 FR 41004-41006.
Draft Handbook of RCRA Groundwater Policies, Page 6
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Groundwater Use Designations
(Updated 4/20/00)
What is a groundwater use designation?
A groundwater use designation is a determination of reasonably expected use, resource value
(e.g., priority), and/or vulnerability of groundwater in a particular area. EPA considers
protective groundwater use designation systems to be those that: (1) are based on an overall
goal which is no less protective than EPA's groundwater protection goal1; (2) are applied
consistently to all groundwaters of a state;
(3) consider the key factors listed in the
adjacent box; and (4) are developed with
thorough public participation. EPA and
States can use the designation as a factor
in determining the maximum2 (highest)
beneficial use of the groundwater in order
to establish facility-specific
for RCRA corrective
action.
How can groundwater use
designations enhance flexibility for
RCRA cleanups?
Regulators can modify
cleanup and
based on groundwater use designations
while still protecting human health and the
environment. This flexibility allows
regulators to focus their resources on
protecting and restoring highly valued
Factors for Groundwater Use
Designations
vulnerability to contamination
hydrogeologic regimes
(recharge and discharge areas)
flow patterns
quantity and potential yield
ambient and/or background quality
wide-spread contamination
current use (including public water sup ply
systems and private drinking water sup ply
wells)
reasonably expected future uses (based on
demographics and availability of alternative
water supplies)
connections to surface waters and
associated ecological receptors
value attributed to groundwater resource,
including public opinion
governmental and legal boundary
considerations (e.g., groundwater migrating
groundwaters and provides more cleanup across state boundaries>
options to facilities. For example,
regulators may allow a facility an extended
remediation time frame to clean up
groundwater when the facility overlies groundwater designated as a future drinking water
source, but which no one is currently using. For groundwater designated for use other than
drinking water use, groundwater cleanup levels would not necessarily be drinking water
standards. Regulators could establish groundwater cleanup levels based on current or other
reasonably expected exposures to contaminants from groundwater.
At a facility-specific level, there may be uses of groundwater or exposures to contaminants
from groundwater which may not be considered in a State groundwater use designation.
When
1 EPA's overall groundwater protection goal is to prevent adverse effects to human health and
the environment and to protect the environmental integrity of the nation's groundwater resources.
2 Within the range of reasonably expected uses, the maximum beneficial groundwater use is the
one which that warrants the most stringent groundwater cleanup levels.
Draft Handbook of RCRA Groundwater Policies, Page 7
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developing facility-specific groundwater cleanup levels, you should consider other common
uses of and exposures to groundwater such as: industrial uses, cooling water, car washes,
livestock watering, and agricultural irrigation. Furthermore, exposures to contaminants from
groundwater could occur even when there is no direct use of the groundwater. For example,
groundwater may recharge to adjacent or underlying aquifers that are used for drinking water,
or discharge to surface water to support
aquatic life, recreation, drinking water,
etc. Additionally, exposure to
contaminants in indoor air could result
from underlying groundwater
contaminated with volatile chemicals.
Regulators should identify the various
uses of and exposures to contaminants
in groundwater to develop protective
groundwater cleanup levels for a facility.
These non-drinking water cleanup levels
could be less stringent and may facilitate
redevelopment of facilities (e.g.
brownfields -
http://www.epa.gov/swerosps/bf/new.htm
) that might otherwise remain unused.
However, non-drinking water exposures
could also result in more stringent
groundwater cleanup levels; for example,
surface water quality standards may be
lower than drinking water standards for
some chemicals. Therefore, it is
important to evaluate various uses and
exposures on a facility-specific basis.
Rationale
for Groundwater Use Designations
EPA believes that states should have the primary
responsibility for managing and protecting their
groundwater resources. Therefore, EPA prefers,
where appropriate, to rely on state groundwater
use designations as a factor in corrective action
decision making. In addition, EPA believes it
has an important role in providing input to state
groundwater use designations because of the
national interest in protecting this valuable
resource and because groundwater often
migrates across state boundaries. EPA's support
of a State groundwater use designation promotes
a consistent and comprehensive approach to
groundwater protection within a State. EPA's
support also indicates that the State has
assessed its groundwaters and developed a
method to prioritize groundwater based on
varying groundwater characteristics. EPA's
primary interest is to promote approaches for
groundwater use designations that are protective
of both the current as well as reasonably
expected uses of groundwater. For example,
EPA wants to avoid inappropriate groundwater
use designations and associated cleanup
decisions that would rely on the lack of current
drinking water use at a particular facility as the
only justification for a non-drinking water use
designation.
Regardless of the groundwater use
designation, facilities should comply with
all State and Federal laws for preventing
new releases of contamination, and do
their part to minimize hazardous waste
generation.
How does EPA's policy on
groundwater use affect States
which consider all of their
groundwater to be a potential drinking water supply?
Some states have statutes, regulations, or policies designating all of the groundwater in the
State to be a potential drinking water supply, and may require that all groundwater be cleaned
up to drinking water standards. None of the policies in this Handbook limit or discourage this
approach in any way. However, EPA still encourages such States to develop methods for
setting groundwater resource priorities so that clean up actions can be prioritized to focus on
facilities in more sensitive areas first. Examples of factors or criteria which States can use to
distinguish among potential drinking waters on a facility-specific basis are:
Draft Handbook of RCRA Groundwater Policies, Page 8
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Expected time frame of future use;
Likelihood of use within a certain time period (e.g., 30 years);
Relative priority or value; or
Relative vulnerability of groundwaters
States are already acquiring this kind of information for other EPA programs. For example,
section 1453 of the Safe Drinking Water Act (SDWA) as amended in 1996 requires states to
develop and implement Source Water Assessment Programs (SWAP). A state SWAP must
provide for assessment of source waters within the state boundaries from which public water
systems in the state receive supplies of drinking water. A SWAP will consist of three
components:
(1) A delineation of the source water area-—that is, the zone contributing water to the
system's wells (for ground water systems) or intakes (for surface water systems).
(2) An inventory of potential sources of contaminants in drinking water within the source
water area. Such sources could include landfills and underground storage tanks.
(3) A susceptibility analysis, which should provide a well-reasoned and well-supported
judgment of the likelihood that a system will actually suffer contamination from any
inventoried sources.
States were required to submit their SWAP for approval by February 1999, and have three and
a half years to complete the assessment following program approval. Most states should have
completed their asessments by November 2002. The results of these assessments must be
made available to the public, and may prove to be helpful in identifying areas needing greater
protection of groundwater resources. For more information on Source Water Assessment
Programs, you should refer to State Source Water Asessment and Protection Programs
Guidance, EPA Doc. No. EPA-816-R-97-009 (August 1997). Electronic information is available
on the internet at .
Who makes groundwater use designations?
EPA prefers to rely on States to develop groundwater use designations. However, EPA may
find it appropriate to use its own guidelines (see below) to make groundwater use designations
when (1) EPA has the lead role in implementing corrective action at a facility, and (2) a state
designation system is not available or is not in EPA's opinion adequately protective of our
nation's groundwater resources.
EPA will generally defer to a State groundwater use designation when it is part of an EPA-
endorsed Comprehensive State Groundwater Protection Program ("CSGWPP") that provides
for facility-specific decision making in EPA's remediation programs3. In the absence of such
an
3 A Comprehensive State Groundwater Protection Program (CSGWPP) is a groundwater management
strategy developed by a state. EPA reviews CSGWPPs and "endorses" those that successfully meet six strategic
activities. EPA outlined specific criteria for each strategic activity in CSGWPP guidance. In particular, EPA
remediation programs review State guidelines in the CSGWPP to prioritize groundwater based upon use, value and
vulnerability. In 1997, EPA's Office of Solid Waste and Emergency Response issued a directive encouraging EPA's
remediation programs to defer to State determinations of current and future use when based on an EPA-endorsed
CSGWPP that has provisions for facility-specific decisions. Go to http://www.epa.gov/OGWDW/csgwpp.html for a
map of states with endorsed CSGWPPs.
Draft Handbook of RCRA Groundwater Policies, Page 9
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EPA-endorsed CSGWPP, EPA may, where appropriate, rely on an alternative State
groundwater use designation. EPA prefers that such alternative state groundwater use
designations comprehensive, be state-wide, be based on use, value and vulnerability, and
would lead to achieving EPA's andJinaLiernediatiorLgoals.
What are EPA 's guidelines for making groundwater use designations?
EPA's guidelines are found in "Guidelines for Groundwater Classification under the EPA
Ground-Water Protection Strategy" (EPA, 1986). These guidelines describe three classes of
groundwater that represent a hierarchy of groundwater resource values to society: Class I is
groundwater which is an irreplaceable source of drinking water and/or ecologically vital, Class
II is groundwater currently used or potentially usable as a source of drinking water; and Class
III includes groundwater that is not a current or potential source of drinking water. As
explained earlier, however, EPA encourages states to make their own groundwater use
designations.
References:
EPA, 1997c. State Source Water Assessment and Protection Programs Guidance (August).
Available at httg^/www.ega.gQWOGJ^ .
EPA, 1997d. The Role of Comprehensive State Groundwater Protection Programs
(CSGWPPS) is OSWER Remediation Programs. OSWER Directive 9283.1-09. Available at
.
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
Particularly
relevant page stating EPA's expectation for contaminated groundwater on 19448.
EPA, 1992. Final Comprehensive State Groundwater Protection Program Guidance, EPA
1 0O-R-93-001 . For more information, refer to
http://www.epa.gov/OGWDW/Pubs/06around.html.
EPA, 1991b. Protecting the Nation's Groundwater: EPA's Strategy for the 1990's. For more
information, refer to
EPA, 1986. Guidelines for Groundwater Classification under the EPA Groundwater Protection
Strategy.
Draft Handbook of RCRA Groundwater Policies, Page 10
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Short-Term Protectiveness Goals
(Updated 4/20/00)
What are EPA's short-term protectiveness goals for groundwater?
Short-term goals associated with groundwater include preventing, minimizing, or eliminating:
(1) current or near-future unacceptable exposures to humans or ecologic receptors from
contaminated groundwater; (2) sources of groundwater contamination; and, (3) the spread of
contaminated groundwater above levels of concern1. EPA has been emphasizing these short
term goals in guidance and training since 1991
when EPA implemented the RCRA "Stabilization
Initiative."
How do facilities achieve these goals?
Facilities should, as appropriate, use interim
actions, sometimes referred to as stabilization
actions, to achieve these goals while pursuing final
remedies. Facilities can implement stabilization
activities at individual source areas, or parts of a
facility.
How does EPA know when facilities
achieve these goals?
EPA tracks the implementation of stabilization
activities at facilities in a computer database known
as RCRIS (RCRA Information System).
EPA also developed two facility-wide Environmental
Indicators to track short-term goals on a national
basis. While EPA continues to track stabilization
activities on a unit or area-specific basis, EPA
believes that facility-wide measures are important to
convey an overall sense of environmental
conditions at a RCRA facility. The two
Environmental Indicators are called "Current Human
Exposures Under Control" and "Migration of Contaminated Groundwater Under Control."
The RCRA Cleanup Reforms focus on achieving these two environmental indicators at 1,714
RCRA Corrective Action Facilities. The program's specific goals, which are also established
under the Government Performance and Results Act, are as follows: by 2005, the States and
EPA will verify and document that 95% of the 1,714 facilities (baseline established in 1997)
have "Current Human Exposures Under Control" and 70% will have "Migration of
Contaminated Groundwater Under Control." You can see the progress toward achieving these
goals at
Rationale for
Short-Term Protectiveness
Goals
The highest priority of the RCRA
Corrective Action Program is to make
sure that people are not being exposed
to risky levels of contaminants.
Another high priority is to protect our
nation'sgroundwaterresources. While
final remedies remain the RCRA
Corrective Action program's long-term
objective, EPA developed two
environmental indicators to focus
resources on early risk reduction and
risk communication. EPA is also
currently using these indicators as
program measures for the Government
Performance and Results Act. These
indicators track the progress being
made nationwide on reducing near
terms risks at RCRA facilities.
1 Levels of concern are generally concentrations of each contaminant in groundwater
appropriate for the protection of the groundwater resource and its maximum beneficial use.
Draft Handbook of RCRA Groundwater Policies, Page 11
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How does a facility achieve an Environmental Indicator?
For Current Human Exposures Under Control, facilities should be able to demonstrate that
there are no current unacceptable human exposures to contamination from the facility. For
"Migration of Contaminated Groundwater Under Control," a facility should be able to
demonstrate that groundwater contamination above levels of concern is not moving beyond
the furthest three-dimensional extent to which a contaminant or contaminants occurring in
groundwater have migrated. These two indicators reflect facility-wide conditions for
contamination that RCRA Corrective Action can address.
Who determines when a facility achieves an Environmental Indicator goal?
EPA or the State determines when a facility achieves an Environmental Indicator goal.
However, facilities or their consultants may assist EPA in the evaluation by providing
information on the current environmental conditions.
Does a facility need to perform additional investigation or cleanup, once the
facility achieves the environmental indicators?
Achieving the Environmental Indicators is an important interim milestone and does not relieve
a facility from meeting investigation objectives or from achieving EPA's
The facility will often need to conduct further investigation to support evaluation and selection
of final remedies. Furthermore, the facility may need to conduct remedial actions that might
be outside the scope of these two Environmental Indicators to achieve other short-term (e.g.,
source control) and final remediation goals for groundwater (e.g., restoring contaminated
groundwater).
How do I consider groundwater use in evaluating "Current Human
Exposures Under Control?"
You should consider whether there is any current human exposure to contaminated
groundwater. This determination relies on actual facility conditions rather than on an aquifer's
use In making this environmental indicator determination, the
regulator considers all reasonably expected direct and indirect ways humans could be exposed
to contaminated groundwater. Some examples of direct routes of exposure include drinking
contaminated groundwater or having skin come into contact with contaminated groundwater
from bathing. Examples of indirect exposure include breathing contaminated vapors entering
buildings from underlying contaminated groundwater, and ingestion of sediments, surface
water or fish that are contaminated from groundwater discharged to surface water.
How do I consider groundwater use in evaluating the "Migration of
Contaminated Groundwater Under Control?"
Regulators should consider the use when establishing the "levels of
concern" in groundwater. Levels of concern are concentrations of each contaminant in
groundwater that are appropriate for the protection of the groundwater resource and its
maximum beneficial use. The level of concern will define the boundary of a contaminant
plume which should not be expanding to meet this indicator. Monitoring locations proximate to
the outer perimeter of the plume should demonstrate that the plume is not migrating above
levels of
Draft Handbook of RCRA Groundwater Policies, Page 12
-------
concern. EPA determines levels of concern on a facility-specific basis, but these would
commonly be the developed to be consistent with the
groundwater use designation and considering other current routes of exposure from
contaminated groundwater. However, a regulator may choose to define the boundary using
more conservative levels of concern, because conservative screening levels may be more
readily available. For example, early in an investigation, the regulator may choose to use
drinking water standards to define the level of concern, because sufficient information is not
yet available to develop appropriate facility-specific concentrations. Generally drinking water
standards will be acceptable to define the boundary of a plume when evaluating this
Environmental Indicator unless more stringent levels are needed based on other actual
exposures to contaminated groundwater (e.g., inhalation).
According to EPA's guidance on Environmental Indicators, the Migration of Contaminated
Groundwater Under Control Environmental Indicator could be achieved even when the plume
is off-site. This position is consistent with the previously stated short-term goal of preventing
further migration of contaminated groundwater. However, remediation of the off-site plume will
often be a high priority for regulators because facilities typically have less ability to control
exposures outside the boundary of the facility.
Can a facility achieve the "Migration of Contaminated Groundwater Under
Control" when groundwater discharges to surface water?
Yes. A facility can achieve this indicator once the regulator determines that the current
discharge of contaminated groundwater into surface water does not cause unacceptable
impacts to surface water, sediments, or eco-systems.
Key References:
EPA, 1999f. Interim Final Guidance for RCRA Corrective Action Environmental Indicators
(February 5). Available at htj|)^/www1ej3ajjov^ .
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/Mav/Dav-01/pr-547.pdf . Particularly
relevant pages describing the stabilization initiative and environmental indicators on 19436-37,
and discussion of interim measures on page 19446-47.
EPA, 1991 a. Managing the Corrective Action Program for Environmental Results: The RCRA
Stabilization Effort (October 25). Available at
http://vosemite.epa.gov/osw/rcra.nsf/d8382df2d09b64668525652800519745/27d1baa5c1dbb
8f38525670f006be76d?OpenDocument
Draft Handbook of RCRA Groundwater Policies, Page 13
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Final Remediation Goals
(Updated 4/20/00)
What are EPA's final remediation goals for groundwater?
EPA believes that you should use the following threshold criteria1 as general goals for cleanup
and screening tools for potential final remedies, including final groundwater remedies:
Rationale for
Final Remediation Goals
EPA's policy on final remediation
goals recognizes that groundwater is
a resource that should be protected
and restored. This policy is important
to ensure the short- and long-term
availability of our Nation's
groundwater resources and to
preserve and protect hydraulically
connected surface water and their
ecosystems.
(1) Protect human health and the
environment.
(2) Achieve media cleanup objectives
appropriate to the assumptions regarding
current and reasonably expected land
use(s) and current and potential beneficial
uses of water resources.
(3) Remediate the sources of releases so as
to eliminate or reduce further releases of
hazardous wastes or hazardous
constituents that may pose a threat to
human health and the environment.
Protecting human health and the environment is
the mandate from the RCRA statute and
regulations; therefore, it is appropriate to include this goal as the first threshold criteria for final
RCRA corrective action remedies. This threshold criterion also serves to ensure that remedies
include protective activities (e.g., providing an alternative drinking water supply) that would not
necessarily be needed to achieve the other criteria. However, EPA also believes that remedies
should meet the second and third criteria as a means to demonstrate progress toward
achieving the overall mandate to protect human health and the environment.
For groundwater remedies, EPA's goal is to protect human health and the environment, which
includes protection of our nation's groundwater resources. In determining appropriate
protection and remediation strategies, EPA will consider the use, value and vulnerability of the
resource. In support of these overall groundwater goals, EPA expects that final remedies, for
facilities subject to RCRA Corrective Action, will return usable groundwaters to their maximum
beneficial use, wherever practicable, within a time frame that is reasonable given the particular
circumstances of the facility. Where restoration of groundwater to appropriate cleanup levels
is not practicable, EPA expects facilities to prevent or minimize the further migration of a
plume, prevent exposure to the contaminated groundwater, and evaluate further risk reduction.
EPA also expects facilities to control or eliminate surface and subsurface sources of
groundwater contamination. In controlling sources, EPA prefers approaches that lead to
permanent reductions in toxicity, mobility, or volume. Additionally, EPA typically expects that
treatment will be used to address source materials considered to be "principal threats," i.e.,
materials that are highly toxic or highly mobile that
1 The 1996 ANPR lists four remedy threshold criteria. EPA no longer believes that the criterion "complying
with applicable standards for waste management" is necessary since complying with applicable waste management
standards is automatically required under existing RCRA Subtitle C and D regulations.
Draft Handbook of RCRA Groundwater Policies, Page 14
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generally cannot be reliably contained or would present a significant risk to human health or
the environment should exposure occur. For a complete list of EPA's expectations for final
remedies, you should refer to page 19448 of the May 1, 1996 AN PR.
How does groundwater use affect the final remediation goal?
Current and reasonably expected groundwater use is a critical factor in determining the final
groundwater remediation goal because EPA's expectation is to "return usable groundwaters to
their maximum beneficial uses." The should serve as a starting
point for determining the maximum beneficial use of the groundwater. You should refer to the
groundwater use designation policy in this Handbook to help you determine whether the use at
a facility will be based on a State designation or the Federal guidelines. To identify other
important aspects of how groundwater use affects final remedies, you should refer to other
topics in this Handbook such as (which includes
of and control,
impracticability, j3erf^maflce,,MQflitoring,, and completing groundwater remedies.
Key Reference:
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
. Particularly relevant
pages: 19448-52.
EPA, 1991 b. Protecting the Nation's Groundwater: EPA's Strategy for the 1990's. Office of
the Administrator. Washington, D.C. For more information, refer to
.
EPA, 1991c. A Guide to Principal Threats an Low Level Threat Wastes. Superfund
Publication 9380.3-06FS (November). Available at
.
Draft Handbook of RCRA Groundwater Policies, Page 15
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Groundwater Cleanup Objectives
(updated 4/20/00)
What are groundwater cleanup objectives?
EPA's general expectation for groundwater remediation is to "return usable groundwaters to
their maximum beneficial uses." EPA recommends that you use clear and concise
groundwater cleanup objectives to help focus evaluation, selection and implementation of
remedies aimed at meeting this
expectation. Groundwater cleanup
objectives are best expressed in terms of
three components:
and
Groundwater
cleanup levels represent specific
concentrations of chemicals designed to
be protective of the groundwater use and
other possible routes of exposure. Point of
compliance represents the locations where
the groundwater cleanup levels should be
achieved at the conclusion of the
groundwater remedy. Remediation time
frames typically include both the time it
would take to implement the remedy and
the estimated time to achieve the
groundwater cleanup levels at the point of
compliance.
Rationale for
Groundwater Cleanup Objectives
Groundwater cleanup objectives should quantify
the scope of cleanup required and create
performance measures to determine whether a
remedy is working. EPA defines groundwater
cleanup levels, point of compliance, and
remediation time frames as the three specific
and measurable components of generic
groundwater cleanup objectives. For each
component, EPA recommends the specific
approaches in this Handbook to ensure
protection of human health and the environment,
now and in the future.
Who specifies groundwater cleanup objectives?
Facilities should recommend groundwater cleanup objectives, including all three components.
Regulators should consider a facility's recommendation when developing groundwater cleanup
objectives to be included in a final remedial decision.
How do groundwater use designations affect groundwater cleanup
objectives?
use generally should influence groundwater cleanup levels and
might affect remediation time frames, but generally should not affect the point of compliance.
You should consider the groundwater use designation when identifying groundwater cleanup
objectives, because those objectives will focus the cleanup on achieving the
of returning contaminated groundwater to its maximum beneficial use(s). The relationship
between the three components of groundwater cleanup objectives and groundwater use is
more fully described in the next three policy discussions in this Handbook.
Draft Handbook of RCRA Groundwater Policies, Page 16
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What is the role of groundwater use in developing facility-specific
groundwater cleanup objectives?
First, you should verify that the use is valid. For example, even if the
State designation defines the aquifer as a non-drinking water resource, regulators and facilities
should verify that no one is drinking the groundwater and that no other unacceptable exposure
to contaminants from groundwater is occurring.
Second, once verified, the groundwater use designation may serve as a starting point for
establishing facility-specific groundwater cleanup objectives. The facility-specific cleanup
objectives should at least be consistent with the groundwater use designation, but should also
consider all known or reasonably expected groundwater uses and potential exposures through
cross-media transfer, such as volatilization into buildings and hydraulic connections to surface
waters and other aquifers. For example, a designation may identify groundwater in a particular
area as not a source of drinking water, but the groundwater discharges into an adjacent
surface water body. In this example, the regulator should establish groundwater cleanup
objectives designed to protect the surface water body.
At a facility-specific level, there may be uses of groundwater or exposures to contaminants
from groundwater which may not be considered in a State groundwater use designation. For
example, other uses of and exposures to groundwater could include: industrial uses, cooling
water, car washes, livestock watering, land irrigation. For example, where groundwater is used
for lawn irrigation, sprinklers could cause unacceptable exposure to children through contact of
contaminated groundwater to their skin or from breathing contaminants that have volatilized
from the groundwater. Furthermore, exposures to contaminants from groundwater could occur
even when there is no direct use of the groundwater. For example, groundwater may recharge
to adjacent or underlying aquifers that are used for drinking water, or discharge to surface
water to support aquatic life, recreation, drinking water, etc. Additionally, exposure to
contaminants in indoor air could result from underlying groundwater contaminated with volatile
chemicals.
After determining all of the current and reasonably expected uses of groundwater at and
around the facility, regulators should make cleanup decisions based on the maximum
beneficial use. Within the range of reasonably expected uses, the maximum beneficial
groundwater use is the one which that warrants the most stringent groundwater cleanup levels.
Key Reference:
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/Mav/Dav-01/pr-547.pdf. Particularly
relevant pages: 19449-52.
Draft Handbook of RCRA Groundwater Policies, Page 17
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Groundwater Cleanup Levels
(updated 4/20/00)
What are groundwater cleanup levels?
Groundwater cleanup levels are facility-specific chemical concentrations in groundwater that a
final remedy should achieve for the remedy to be considered complete. Groundwater cleanup
levels should consider use and protect human health and the
environment. Additionally, groundwater cleanup levels often serve as the basis for identifying
the "level of concern" used for the Migration of Contaminated Groundwater Under Control
environmental indicator.
How should groundwater cleanup levels
be developed?
Groundwater cleanup levels for human health
should typically either be developed by using
existing cleanup standards (e.g. drinking water
standards) or developed based on the degree
of actual or potential exposure to a
groundwater contaminant (resulting in an
estimate of dose) and the toxicity of the
contaminant resulting in an estimate of risk.
Once an appropriate exposure scenario is
determined, groundwater cleanup levels are
calculated to fall within generally acceptable
levels of risk. EPA recommends that
regulators choose risk-based cleanup levels as
follows:
Rationale
for Groundwater Cleanup Levels
Groundwater clean up levels provide clear
numerical targets. These targets are
important to measure both progress and
completion of a ground water clean up. The
selection of groundwater cleanup levels
based on the current use as well as the
groundwater use designation allows
stakeholders to recognize various uses of
the groundwater. This approach ensures
current as well as future protection of
human health and the environment.
1. For known or suspected carcinogens, regulators should establish groundwater cleanup
levels at concentrations which represent an excess upper bound lifetime risk2 to an
individual of between 1x10"4 and 1x10"6 (commonly referred to as EPA's risk range).
Note that EPA prefers cleanup levels at the more protective end of the risk range. For
facilities with multiple contaminants or exposure pathways, cleanup levels should
generally be set so that cumulative (total) excess upper bound lifetime risk from all
contaminants still falls within the risk range.
2. For toxicants associated with adverse effects other than cancer, groundwater cleanup
levels should be established at concentrations to which human populations, including
sensitive subgroups could be exposed on a daily basis without appreciable risk of
negative effect during a lifetime. Such levels are generally interpreted as equal to or
EPA expresses cancer risk in terms of the likelihood that a person might develop cancer from exposure
to contaminants from a facility. For example, a risk assessment might say that a receptor has an upper bound
excess cancer risk of 1x10~4. The numerical estimate means that if 10,000 people received this level of exposure
averaged over a 70-year lifetime, no more than one would have a probability of developing cancer. Depending on
facility-specific factors, EPA's threshold of acceptable cancer risk ranges from 1 x 10~6 to 1 x 10~4, or from one in
one million to one in ten thousand. Screening values are generally set at a cancer risk of 1x10~6.
Draft Handbook of RCRA Groundwater Policies, Page 18
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below a hazard quotient of one3. For facilities with multiple contaminants or exposure
pathways, groundwater cleanup levels should generally be equal to or below a hazard
index of one4.
In addition to protecting human health, groundwater cleanup levels should protect
unacceptable cross-media transfer and unacceptable risks to ecologic receptors. For
additional guidance on ecologic risk issues, you should refer to numerous resources
developed by EPA's Superfund Program avalable at
.
What is the role of groundwater use in setting cleanup levels?
The use is typically the starting point for determining the appropriate
exposure scenarios to evaluate risks and identify cleanup levels. For groundwater that is
currently used or designated as a current or reasonably expected source of drinking water,
regulators should select cleanup levels protective for residential use. For constituents with
maximum contaminant levels (MCLs) promulgated under the Safe Drinking Water Act,
regulators generally establish groundwater cleanup levels as MCLs. For constituents for which
no MCLs have been promulgated, regulators may rely on other established drinking water
standards or a risk assessment incorporating standard residential exposure assumptions (for
example, ingestion rate of 2 liters/day, exposure frequency of 350 days/year, etc.) to estimate
contaminant dose, derive risk estimates, and determine groundwater cleanup levels.
What is the cleanup level if no one is drinking the groundwater?
Even if no one is currently drinking the groundwater, the cleanup level may still be based on
drinking water use if the aquifer is considered by EPA or the State to be a reasonably
expected future source of drinking water. Stakeholders should consider State
use when deciding whether an aquifer is a reasonably expected future source of
drinking water.
What is the cleanup level if the groundwater use is designated as non-
drinking water?
For a non drinking water groundwater use designation, the cleanup level might not be based
on drinking water, but should be protective for other uses and exposures that could occur
under its designation. Such uses and exposures could include: sanitary purposes at an
industrial facility (including showering), industrial cooling water, car washing, agricultural uses
and irrigation. Furthermore, exposures to contaminants from groundwater could occur even
when there is no direct use of the groundwater. For example, groundwater may recharge
adjacent or underlying aquifers that are used for drinking water or may discharge to surface
3 EPA expresses non-cancer health risk as a ratio, known as the Hazard Quotient (HQ), which is defined
as the calculated exposure from a single contaminant in a single medium divided by a reference dose. The
reference dose is the level of exposure that EPA believes will be without adverse effect in human populations,
including sensitive individuals. Note that some chemicals may be associated with both carcinogenic as well as
non-carcinogenic effects (such as liver or kidney disease); both should be considered when setting the cleanup
level.
4 The hazard index (HI) assesses potential for toxicity following exposure to multiple contaminants. It is
equal to the sum of the hazard quotients. However, where information is available to identify the critical toxic effect
for non-carcinogens, only hazard quotients with associated with similar critical effects (target organs) are combined.
Draft Handbook of RCRA Groundwater Policies, Page 19
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water to support aquatic life, recreation, or drinking water, etc. Additionally, exposure to
contaminants in indoor air could result from underlying groundwater contaminated with volatile
chemicals. Facilities should identify the various uses and exposures (i.e. pathways) to
contaminants from groundwater to develop protective groundwater cleanup levels for the
facility. To estimate dose, you should evaluate all current and potential routes of exposure
within each pathway, such as inhalation, dermal contact, and inadvertent ingestion. EPA does
not currently have standard exposure assumptions for most non-residential uses of
groundwater. Facilities, in consultation with the regulators, generally should quantify facility-
specific exposure assumptions for all expected pathways by collecting facility-specific or other
relevant data to develop an appropriate numerical value for those exposures. These
exposure values along with toxicity values for each contaminant are then used to calculate
contaminant-specific concentrations (groundwater cleanup levels) to achieve protective risk
levels (i.e. an excess upper bound lifetime cancer risk of 1x10"4 to 1x10"6 or a hazard index of
one).
Some States have established generic cleanup levels for groundwater in non-drinking water
aquifers. In those states, facilities and regulators should consider these levels when
appropriate.
Are there any situations where the levels described above might not be
appropriate?
Yes. For example, groundwater cleanup levels that are higher or lower than the levels
described above, might be appropriate in the two following circumstances, provided such
cleanup levels protect human health and the environment:
(1) Higher cleanup levels may be appropriate, for a given facility, when groundwater is also
contaminated by hazardous constituents that are naturally occurring5, or have
originated from a source not associated with the subject facility, and those hazardous
constituents are present in concentrations such that remediation of the release would
not provide significant reduction in risks to actual or potential receptors.
(2) Lower groundwater cleanup levels may be necessary because of unacceptable risks to
human receptors from combined effects of hazardous wastes or hazardous
constituents, or to protect potential receptors exposed through cross media transfer, or
to protect ecologic receptors.
Are there any situations where I don't need to set a groundwater cleanup
level?
Yes. In some cases, the groundwater will already be at acceptable levels for its designated
use(s). In other situations, regulators might not establish specific groundwater cleanup levels
if: the contaminated groundwater is within a designated non-drinking water aquifer; has no
current or foreseeable beneficial use; does not discharge to surface water or to a drinking
water aquifer at levels that could cause concern; and does not cause other exposures through
media transfer (e.g., indoor air). However, the regulator may still require you to conduct
monitoring to ensure continued protection of human health and the environment. Other EPA
policies dealing with issues, such as would still likely apply in this situation.
Naturally occurring substance in its unaltered form, or altered solely through naturally occurring
processes or phenomena, [in] a location where it is naturally found (Superfund, Section 104(a)(3)(A)).
Draft Handbook of RCRA Groundwater Policies, Page 20
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Do alternate concentration limits apply to setting groundwater cleanup
levels for facility-wide corrective action?
Alternate Concentration Limits (ACLs) apply to corrective action at RCRA regulated units6, and,
therefore, would not typically apply to facility-wide corrective action. ACLs are levels that can
be used, as appropriate, to establish groundwater protection standards7 for RCRA regulated
land based units (i.e., all surface impoundments, waste piles, land treatment units, and landfills
that received hazardous waste after July 26, 1982). These units are subject to groundwater
monitoring and corrective action requirements contained in 40 CFR Part 264, Subpart F.
ACLs, which are established in 40 CFR 264.94(b), allow for groundwater protection standards
developed based on risk rather than background, and allow decision makers to consider
natural attenuation processes in remediating groundwater contamination from RCRA regulated
units, where appropriate. Both of these concepts (i.e., risk-based standards and natural
attenuation approaches) are available for facility-wide corrective action as explained in other
policies discussed in this Handbook. If you have a regulated unit and want to use ACLs, you
should read the Alternate Concentration Limit Guidance, July 1987 and call the overseeing
regulator.
Under limited circumstances specified in CERCLA 121(d)(2)(B)(ii), ACLs may also be used at
Superfund sites. Guidance for using Superfund ACLs is found in the "Rules of Thumb for
Superfund Remedy Selection" (EPA, 1997).
What are my cleanup levels for groundwater if I am clean closing a RCRA
regulated unit?
To achieve "clean closure," facilities should remove or decontaminate all hazardous waste,
liners and environmental media contaminated by releases from the unit. However, hazardous
constituents may remain at some level in environmental media, such as groundwater, after
clean closure provided the constituents are below levels that may pose a risk to human health
or the environment. In 1998, EPA issued a memorandum broadening the interpretation of
acceptable levels of residual constituents. This expanded interpretation allows the use of non-
residential exposure assumptions to be incorporated into the development of closure
standards (i.e. the concentrations that each medium should achieve for the unit to be clean
closed.) When the groundwater protection standards are based on a
other than drinking water standards, EPA or the State should be confident that the
exposure assumed remains valid (e.g., periodic evaluations of actual use, zoning and/or
easements to third parties) since no further regulatory control will be required under subtitle C.
For more information on risk based closure, you should read the Risk-Based Clean Closure
Memorandum and call your overseeing regulator.
Regulated units are defined in 40 CFR 264.90 as surface impoundments, waste piles, land treatment
units, and landfills that received hazardous waste after July 26, 1982.
Groundwater protection standards are constituent concentrations established in permits which trigger
corrective action and demonstrate satisfaction of closure requirements.
Draft Handbook of RCRA Groundwater Policies, Page 21
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References:
EPA, 1998c. Memorandum from Elizabeth Cotsworth to RCRA Senior Policy Advisors titled,
Risk-Based Clean Closure (March 16). Available at
.
EPA, 1997b. Rules of Thumb for Superfund Remedy Selection (EPA 540-R-97-013).
Available at
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
Particularly
relevant pages: 19448-52.
EPA, 1987. Alternate Concentration Limit Guidance (EPA/530-SW-87017).
Draft Handbook of RCRA Groundwater Policies, Page 22
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Point of Compliance
(Updated 4/20/00)
What is the groundwater point of compliance forRCRA Corrective Action?
The point of compliance for groundwater, in
where the facility should meet
the context of RCRA corrective action, represents
within a contaminated aquifer at the
conclusion of a final remedy (i.e., the
facility has achieved its
Facilities should generally meet
groundwater cleanup levels throughout the
area where groundwater is contaminated
above the cleanup level(s), or, when waste
is left in place, throughout the plume
beyond the boundary of the waste
management area encompassing the
original source(s) of groundwater
contamination. EPA typically refers to this
approach as the "throughout-the-
plume/unit boundary" point of compliance.
This definition of point of compliance is
consistent with "area of attainment" (EPA,
1988) and "point of compliance" (EPA,
1997) for groundwater remedies under the
Superfund cleanup program.
EPA recognizes that achieving
groundwater cleanup levels at the point of
compliance in many circumstances may
take a considerable length of time.
Therefore, facilities and regulators may
want to consider establishing other interim
milestones by which progress can be
measured. Examples of such other
milestones could include the time when a facility documents that the remedy has been
constructed and it is operating successfully.
Factors to consider when developing a facility-specific groundwater point of compliance
include proximity of sources and technical practicability of groundwater remediation.
What is the point of compliance when a facility has more than one source of
groundwater contamination?
If waste is left in place in multiple areas in close proximity to each other, the point of
compliance should be throughout the plume beyond the boundary of a "waste management
area" encompassing all of these sources. If the sources are not close each other, the point of
compliance should be established throughout the plume beyond the boundaries of the
individual areas where waste is left in place as part of a final remedy.
Rationale
for Point of Compliance
The "throughout-the-plume/unit boundary" point
of compliance for groundwater represents
current EPA policy because it is consistent with
EPA's by not allowing the
spread of contamination, and by restoring more
of the nation's groundwater resources to
beneficial use. For example, if the remedial
goal is to restore the groundwater to be suitable
for drinking water, the throughout-the plume/unit
boundary point of compliance will help you to
determine when restoration of all of the
contaminated groundwater has been attained so
that no further controls are necessary.
EPA's policy on the groundwater point of
compliance avoids the need to install
groundwater monitoring devices through waste,
such as in a landfill, that is left in place as part of
a final remedy.
Draft Handbook of RCRA Groundwater Policies, Page 23
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How does a technical impracticability determination affect the point of
compliance?
The "throughout-the-plume/unit boundary" point of compliance for groundwater would generally
apply even in the context of a (Tl) determination (see discussion in
this Handbook on Technical Impracticability). However, the goal of achieving groundwater
cleanup levels should apply outside the spatial area (Tl zone) identified by the facility and
approved by the regulator in a Tl determination. This Tl zone is similar to a waste
management area described previously in this policy, and the point of compliance for
groundwater should be throughout the plume beyond the limit of the Tl zone. The facility in
this context would generally not be responsible for achieving groundwater cleanup levels within
the Tl zone as long as the regulator agrees that the Tl determination remains valid. It is
important to remember that even if a remedy achieves cleanup levels outside the Tl zone, a
facility's corrective action obligations for implementing, maintaining and monitoring the
containment within the Tl zone should continue (1) as long as these obligations are necessary
to protect human health and the environment, or (2) until such time that cleanup within the Tl
zone becomes technically practicable and the cleanup levels are achieved throughout the
entire plume (i.e., even within the formerly identified Tl zone).
What is the role of groundwater use in establishing a point of compliance
for groundwater?
Under RCRA Corrective Action, the groundwater use designation should not affect the point of
compliance1. However, the groundwater use designation may affect
that the facility attains at the point of compliance, and may also affect
frames.
Key Reference:
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/Mav/Dav-01/pr-547.pdf. Particularly
relevant page: 19450.
EPA, 1988. OSWER Directive 9283.1-2, "Guidance on Remedial Actions for Contaminated
Groundwater at Superfund Sites," (December 1).
The May 1, 1996 ANPR recommended that groundwater vulnerability, use and likely exposures be
considered as factors in establishing a groundwater point of compliance. EPA generally believes that vulnerability,
use and likely exposures should be considered when establishing groundwater cleanup levels and remediation time
frames, but they should not generally affect the point of compliance. Retaining the throughout the plume/unit
boundary point of compliance, regardless of groundwater use, provides a means for a facility to demonstrate that
cleanup levels based on the designated groundwater use have been achieved throughout the facility, and that they
have fulfilled all corrective action obligations concerning contaminated groundwater. EPA, however, remains
interesting in comments on this issue.
Draft Handbook of RCRA Groundwater Policies, Page 24
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Remediation Time Frame
(Updated 4/20/00)
What is the remediation time frame?
The remediation time frame for groundwater is the facility-specific schedule for a groundwater
remedy. It includes the time frame to construct the remedy and an estimate of the time frame
to achieve at the pMniM.com,|)ljance, EPA believes that
remediation time frame should be reasonable
based on facility-specific conditions and
consider the following factors where
appropriate:
groundwater
nature and extent of contamination
reliability of exposure controls
capabilities of technologies
availability of treatment and/or
disposal capacity of remediation
wastes
costs for alternative water supplies
when the groundwater might be used
community preferences
financial resources of the facility
What is the role of groundwater use
in determining remediation time
frames?
Rationale
for Remediation Time Frame
EPA's policy on remediation time frame
provides flexibility that can maintain
protective ness while improving cost
effectiveness. Recognizing a longer-
remediation time frame can provide a
greater range of possible cleanup options.
For example, monitored natural attenuation
might be appropriate where a longer
remediation time frame is acceptable. By
accepting reasonable remediation time
frames, the RCRA Corrective Action
program can direct its resources on
achieving short-term protectiveness goals at
more facilities, while maintaining its long-
term goals.
Groundwater use is an important factor in
estimating time frames. For example, if no
one is currently drinking the groundwater, a longer remediation time frame may be acceptable.
However, a regulator is more likely to accept a long time frame when the contaminant plume is
not expanding, source control measures are implemented, there is adequate monitoring, and
controls are in place to prevent exposure (e.g., drinking water wells are prohibited).
In what types of situations might specific remediation time frames not be
defined?
An estimate of the needed to achieve
might not be necessary when the facility-specific does not
include a specific goal of returning the contaminated groundwater to its designated use (e.g.,
impracticability). However, even in this circumstance, you should include a
remediation time frame associated with how long it will take to implement the alternative
remedial strategy (e.g, containment system) and achieve its goals.
Key Reference:
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
Particularly
relevant page: 19450.
Draft Handbook of RCRA Groundwater Policies, Page 25
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Source Control
(Updated 4/20/00)
What does source control mean?
Source control refers to a range of actions (e.g. removal, treatment in place, containment, etc.)
designed to protect human health and the
environment from sources of contamination.
EPA considers source control as an important
element in final remedies (see
Goals).
What are sources of contamination?
EPA defines sources as contaminated material
that acts as a reservoir for the continued
migration of contamination to surrounding
environmental media (i.e. soil, groundwater,
surface water, sediment, or air), or provides a
direct threat to a receptor. Sources are not
always stationary, but can migrate from a
location, such as a landfill or surface
impoundment, where the contamination was
originally released. For example, dense non-
aqueous phase liquids (DNAPLs) may be
present as a "mobile" phase that continues to
migrate deeper into the subsurface, migrate
along a subsurface feature, or accumulate in a
subsurface feature, such as a depression in a
low permeable layer of clay.
Rationale
for Source Control
EPA's continuing emphasis on source
control reflects the Agency's strong
preference for remedies that are
protective in the long term. For
groundwater, source control is critical to
return our nation's contaminated
groundwaters to their maximum
beneficial uses in a reasonable time
frame, and to ensure that
uncontaminated groundwater is
available for future generations.
Controlling sources of contamination is
also consistent with the Agency's long-
standing policies dealing with pollution
prevention; it is generally easier to deal
with the contamination at the source
than to clean up wide-spread
contamination.
What are EPA's general expectations for source control regarding
groundwater?
EPA generally expects facilities to control or eliminate surface and subsurface sources of
groundwater contamination. Facilities should implement source controls as necessary to
achieve For example, placing a temporary cover over highly
contaminated soils may be appropriate to prevent leaching of the contaminants to underlying
groundwater in the short-term while a facility pursues long-term remedies. EPA believes that
source control is also a key element of final remedies that are selected to achieve
remediation As such, EPA questions whether final remedies that fail to include source
control would meet the overall RCRA statutory mandate to protect human health and the
environment.
When should I consider source control measures?
You should consider source control measures as early as possible to: (1) evaluate whether
source controls are necessary to achieve short-term protectiveness goals; (2) establish
investigation data needs; and, (3) develop cleanup options to achieve final remediation goals.
Draft Handbook of RCRA Groundwater Policies, Page 26
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When can I contain the sources rather than treat them?
EPA prefers approaches that use treatment to address wastes and contaminated media that
EPA considers "principal threats." EPA considers sources or "source materials" to be principal
threats when they are highly toxic or highly mobile that generally cannot be reliably contained
or would present a significant risk to human health or the environment should exposure occur.
EPA expects to use engineering controls, such as containment, for wastes and contaminated
media which can be reliably contained, pose relatively low long-term threats, or for which
treatment is impracticable. The exact balance between treating, removing, and containing the
source is best determined on a case-by-case basis during remedy evaluation and selection.
Along with identifying principal threats, you should also generally consider other factors such
as long-term reliability, short-term risks, and community acceptance when evaluating the right
balance between containment and treatment.
In some situations, it may be appropriate to contain rather than treat even principal threat
wates due to difficulties in treating the wastes. For example, the following situations (EPA,
1997) could justifiably lead a regulator to decide that containment rather than treatment would
be acceptable for principal threat wastes:
Treatment technologies are not technically feasible or are not available within a
reasonable time frame;
The extraordinary volume of materials or complexity of the site may make
implementation of the treatment technologies impracticable (e.g., large landfills);
Implementation of a treatment-based remedy would result in greater overall risk to
human health and the environment due to risks posed to workers, the surrounding
community, or impacted ecosystems during implementation (to the degree that these
risks cannot be otherwise addressed through implementation measures); and
Implementation of the treatment technology would have severe effects across
environmental media.
How does groundwater use affect source control?
EPA generally expects facilities to control the sources of contamination regardless of the
current groundwater use or the groundwater use designation. However, the current use and
reasonably expected future uses of groundwater may impact the urgency for implementing
source control measures.
Why should I control sources when I've already achieved Environmental
Indicators?
Environmental Indicators are only a milestone on the way to meeting
and completing corrective action. In most cases, source control will be necessary to restore
groundwater to its maximum beneficial use within a reasonable time frame.
Draft Handbook of RCRA Groundwater Policies, Page 27
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Key References:
EPA, 1997b. Rules of Thumb for Superfund Remedy Selection, OSWER Directive No.
9355.0-69 (August). Available at
http://www.epa.gov/oerrpage/superfund/resources/rules/index.htm . Particularly relevant
pages pertaining to applicability to RCRA Corrective Action on page 1, and on Treatment of
Principal Threat Wastes on pages 11 and12.
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/IVIay/Dav-01/pr-547.pdf. Particularly
relevant pages: 19448.
EPA, 1991c. A Guide to Principal Threats an Low Level Threat Wastes. Superfund
Publication 9380.3-06FS (November). Available at
http://www.epa.gov/oerrpage/superfund/resources/gwdocs/threat.pdf.
Draft Handbook of RCRA Groundwater Policies, Page 28
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Monitored Natural Attenuation
(Updated 4/20/00)
What is monitored natural attenuation?
The term "monitored natural attenuation" refers to an approach to clean up environmental
contamination by relying on natural processes and monitoring. Natural attenuation processes
include a variety of physical, chemical, or biological processes that, under favorable conditions,
act without human intervention to reduce the mass, toxicity, mobility, volume or concentration
of contaminants in groundwater.
When is monitored natural attenuation a likely cleanup option?
MNA may be an acceptable cleanup option when the facility can demonstrate that the remedy
is capable of achieving the overall RCRA statutory mandate to protect human health. In
addition, EPA looks more favorably on those MNA proposals that would where:
the facility can demonstrate that MNA will be able to achieve
objectives:
measures for of groundwater contamination are already in-place;
the dominant natural attenuation processes cause degradation or destruction of
contaminants as opposed to those processes that merely dilute contamination or
prevent its movement;
the contaminant plume(s) is already
stable or shrinking in extent; and,
the facility uses MNA in conjunction with
an active remedial system or as a follow-
up measure.
Is monitored natural attenuation
acceptable when contaminated
groundwater is off-site?
The April 21, 1999 EPA Policy Directive on
monitored natural attenuation does not
distinguish between on-site and off-site
contaminated groundwater. Therefore, using a
monitored natural attenuation remedy for off-site
contaminated groundwater would not be in
conflict with EPA policy provided that the remedy
is consistent with the rest of EPA's guidance. For
example, if a plume is already off-site, regulators
might accept a monitored natural attenuation
remedy when no one is currently exposed to the
contaminated groundwater and it meets EPA's
Other very
important factors for relying on monitored natural
attenuation for off-site contamination include thorough public participation, and the ability to
conduct long-term monitoring and prevent exposures.
Rationale for
Monitored Natural Attenuation
This policy reflects EPA's commitment to
groundwater protection, and promotes
responsible use of monitored natural
attenuation remedies. This policy also
reflects advancements in EPA's
understanding of how natural attenuation
processes can be part of effective
remedial strategies. Monitored natural
attenuation is not a "no action" remedial
alternative. Appropriate use of monitored
natural attenuation supports EPA's
remediation objectives which include
source control, prevention of plume
migration, and restoration of
contaminated ground waters to maximum
beneficial uses.
Draft Handbook of RCRA Groundwater Policies, Page 29
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How long should a facility monitor a Monitored Natural Attenuation
Remedy?
A facility should monitor until the are met at the of
EPA specifically added the term "monitored" to the name of this remedial
alternative to emphasize the importance of long-term performance monitoring. EPA's Policy
Directive states, "Performance monitoring should continue until remediation objectives have
been achieved, and longer if necessary to verify that the facility no longer poses a threat to
human health or the environment." However, the Directive also emphasizes that it is important
to include flexibility sufficient to adjust the frequency (more frequent or less frequent) of
monitoring as the situation warrants.
How does groundwater use influence a monitored natural attenuation
remedy?
Current use and the are important to consider when evaluating a
monitored natural attenuation remedy. Stakeholders should be aware of the current uses of
groundwater in the vicinity of the facility and be confident that the contaminated groundwater
does not represent an unacceptable threat to those users. Stakeholders should also consider
other possible ways exposure from the contaminated groundwater could occur. For example,
certain chemicals present in groundwater could volatilize, migrate as a gas into structures and
expose humans to unacceptable concentrations of indoor air contamination. Contaminants
could also migrate from groundwater into surface water resulting in unacceptable exposures to
humans and or ecologic receptors using that surface water. Stakeholders should recognize
that a potential drinking water designation does not by itself preclude a protective monitored
natural attenuation remedy. For example, monitored natural attenuation might be a good
remedial option for groundwater that is designated as a potential source of drinking water, but
not expected to be used for that purpose in the near future. Stakeholders considering
monitored natural attenuation should refer to the discussion of the various uses of
groundwater in the groundwater use designation policy contained in this Handbook, and make
sure that the remedy will be adequately protective.
Key References:
EPA, 1999e. Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action and
Underground Storage Tank Sites (April 21). OSWER Policy Directive 9200.4-17P. Available
at . Other helpful links regarding MNA
available at and
.
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/IVIay/Dav-01/pr-547.pdf. Particularly
relevant pages: 19451-52.
Draft Handbook of RCRA Groundwater Policies, Page 30
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Technical Impracticability
(Updated 4/20/00)
What does technical impracticability mean?
Technical impracticability (Tl) refers to a situation where achieving
is not possible from an "engineering perspective." The phrase "engineering
perspective" refers to how factors such as feasibility, reliability, scale and safety influence the
ability to achieve groundwater cleanup objectives. For example, a certain cleanup approach
might be technically possible, but the scale of the operation might be of such magnitude, that it
was not technically practicable.
What are the primary causes that
might lead to a technical
impracticability determination?
Reasons for technical impracticability
generally fall into one of two categories:
(1) Hydrogeologic factors
(2) Contaminant-related factors
Examples of limiting hydrogeologic factors
could include very low-permeable or highly
heterogeneous soils, or complex fractures or
solution cavities in bedrock. An example of
a contaminant-related factor could be
presence of residual non-aqueous phase
liquids (NAPLs), although there have been
many advancements in NAPL remediation in
recent years.
Rationale
for Technical Impracticability
Technical impracticability determinations offer
a realistic approach to address those situations
where currently there are limitations to
groundwater restoration. EPA believes that it
is appropriate to openly discuss technology
limitations rather than establishing unrealistic
goals. By recognizing technical
impracticability where scientifically justified,
we can focus resources on an alternative
remedial strategy that is practicable.
Poor cleanup performance due to inadequate remedial design is not sufficient justification for a
technical impracticability determination. Design inadequacies could stem from, for example,
inadequate characterization, insufficient pumping rates, improper well placement, or selecting
inappropriate technologies.
Is the mere presence of non-aqueous phase liquids (NAPLs) sufficient to
justify a technical impracticability determination?
No. The presence of NAPL is just one of many factors you should consider when evaluating
technical impracticability. Other factors to consider are the type, amount, and location of
NAPL, as well as the technologies that are available to clean up the NAPL. Facilities should
avoid basing their technical impracticability demonstration on just the presence of NAPL or the
apparent inability of any one technology (e.g., pump-and-treat). A technical impracticability
determination should be based on a good understanding of hydrogeologic factors, chemical
characteristics, and conventional as well as innovative technologies.
Draft Handbook of RCRA Groundwater Policies, Page 31
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When should a facility recommend Technical Impracticability?
Considering technical impracticability early in corrective action (e.g., during facility
characterization) is a good idea if you believe a facility has hydrogeologic or chemical-related
cleanup limitations. The facility should submit a technical impracticability demonstration along
with a recommendation for a final remedy. However, we suggest you do not devote resources
on a technical impracticability demonstration until you've achieved the
goals (e.g., environmental indicators).
Who decides whether cleanup of the groundwater is technically
impracticable?
The facility should develop and submit a technical report demonstrating that achieving the
groundwater cleanup objectives is technically impracticable. The regulator makes the
technical impracticability determination when selecting a final remedy.
What should facilities include in a technical impracticability demonstration?
EPA's guidance (EPA, 1993) on technical impracticability suggests the following:
Spatial area (the Tl zone) over which the Tl decision would apply;
Specific groundwater cleanup objectives that are considered technically impracticable
to to achieve;
Conceptual site model that describes geology, hydrology, groundwater contamination
sources, transport and fate;
Evaluation of the "restoration potential" of the Tl zone;
Cost estimates;
Any additional information EPA or the State program deems necessary; and
Description of an alternative remedial strategy.
If I get a technical impracticability determination, have I completed
corrective action for groundwater?
No. When the regulator determines that achieving groundwater objectives is technically
impracticable, the facility should implement an "alternative remedial strategy." That strategy
must protect human health and the environment and should:
be technically practicable;
control the sources of contamination and prevent migration of contamination beyond
the zone associated with the technical impracticability determination;
achieve the groundwater cleanup objectives outside the zone associated with the
technical impracticability determination; and,
be consistent with the overall cleanup goals for the facility.
Draft Handbook of RCRA Groundwater Policies, Page 32
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How much facility investigation do I have to conduct within the technical
impracticability zone?
You should characterize your facility within the Tl zone to: (1) support the technical
impracticability demonstration; (2) identify sources that you should control, even within the Tl
zone; (3) evaluate the potential for cross-media transfer of contamination that may need to be
managed (e.g., from groundwater to air) as part of an alternative remedial strategy; and (4)
support the development of an alternative remedial strategy as discussed above. The
circumstances of the facility will govern the amount of characterization needed to accomplish
these objectives.
Why should I control sources within the technical impracticability zone?
is generally an important part of an acceptable alternative remedial strategy
and is one of the three recommended threshold criteria for final remedies. Source control
prevents the continued input of contamination into surrounding environmental media and can
help improve the likelihood that the alternative remedial strategy will be effective in the long-
term. Controlling sources within the technical impracticability zone will help to limit the amount
of contamination you will need to address if and when achieving the
objectives becomes technically practicable in the future.
How does a technical impracticability determination affect the point of
compliance?
The "throughout-the-plume/unit boundary" for groundwater would generally
apply even in the context of a Tl. However, the goal of achieving groundwater cleanup levels
should apply outside the spatial area (Tl zone) identified by the facility and approved by the
regulator in a Tl determination. This Tl zone is similar to a waste management area described
in this Handbook (see point of compliance). Where a regulator has made a Tl determination,
the point of compliance for groundwater water should be throughout the plume beyond the limit
of the Tl zone. The facility in this context would generally not be responsible for achieving
groundwater cleanup levels within the Tl zone as long as the regulator agrees that the Tl
determination remains valid. It is important to remember that even if a remedy achieves
cleanup levels outside the Tl zone, a facility's corrective action obligations for implementing,
maintaining and monitoring the containment within the Tl zone should continue (1) as long as
these obligations are necessary to protect human health and the environment, or (2) until such
time that cleanup within the Tl zone becomes technically practicable and the cleanup levels
are achieved throughout the entire plume (i.e., even within the formerly identified Tl zone).
How long should a technical impracticability determination last?
Under EPA's technical impracticability guidance (EPA, 1993), for RCRA Corrective Action,
technical impracticability determinations at RCRA facilities, and the responsibility of the facility
to manage their facility under the alternative remedial strategy, typically should remain in effect
until subsequent advances in technology make achievement of the
objectives technically practicable. Under this guidance, regulators may require facilities to
revisit technical impracticability determinations in the future. Revisiting the technical
impracticability determination may be appropriate when new information concerning facility
conditions or new technologies indicate that the facility can achieve the groundwater cleanup
Draft Handbook of RCRA Groundwater Policies, Page 33
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objectives. Sometimes, a facility might want to revisit the technical impracticability
determination on its own. For example, the facility might want try a new technology that has
the ability to achieve the cleanup objectives rather than indefinitely paying for operating and
maintenance costs associated with the alternative remedial strategy. Technical impracticability
determinations are based on current understanding of capabilities and limitations of cleanup
technologies. Stakeholders should consider that future advancements in technologies could
overcome today's limitations.
How does groundwater use affect a Technical Impracticability
determination?
The use affects a technical impracticability determination because:
You should use the current groundwater use and the groundwater use designation to
develop groundwater cleanup objectives; and,
A successful technical impracticability demonstration should show that facility
conditions prevent the facility from achieving groundwater cleanup objectives.
Therefore, regulators should establish groundwater cleanup objectives prior to considering
technical impracticability. For example, if the groundwater use designation is not drinking
water, then restoring the contaminated groundwater to drinking water standards might not
apply. In a situation where drinking water standards do not apply, the technical impracticability
determination would then be based on the inability to achieve groundwater cleanup objectives
developed to protect non-drinking water use, such as protection of surface water.
You should also account for current and reasonably expected groundwater use when
developing a protective alternative remedial strategy. For example, the long-term reliability of
containment technologies and the extent of monitoring, operation and maintenance are critical
when groundwater near the facility is currently used for drinking.
Key References:
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/IVIay/Dav-01/pr-547.pdf. Particularly
relevant page: 19451.
EPA, 1993. Guidance for Evaluating the Technical Impracticability of Groundwater Restoration
EPA/540-R-93-080, (September). Available at
http://wvwv.epa.gov/oerrpage/superfund/resources/gwdocs/techimp.htm.
Draft Handbook of RCRA Groundwater Policies, Page 34
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Injection of Contaminated Groundwater
(Updated 4/20/00)
Can I inject groundwater that is contaminated with hazardous wastes back
in the subsurface as part of corrective action?
RCRA section 3020(a) bans hazardous waste
disposal by underground injection into or above an
underground source of drinking water located within
1/4 mile from an injection well. However, RCRA
section 3020(b) exempts from that ban the injection
of groundwater contaminated with hazardous
wastes provided that certain conditions are met.
What are the specific conditions I have to
meet prior to injecting groundwater
contaminated with hazardous waste into
the subsurface?
Rationale
for Injection of Contaminated
Groundwater
EPA intends to promote more
frequent use of in-situ bio remediation
and other in-situ treatments where
such technologies are protective and
offer advantages over other
approaches.
The exemption provided by RCRA section 3020(b)
will allow you to inject contaminated groundwater, which is contaminated with hazardous
wastes, back into the aquifer from which it was withdrawn if the contaminated groundwater is
treated to substantially reduce hazardous constituents prior to such injection. Additionally, that
injection needs to be part of a response action under section 104 or 106 of the Comprehensive
Environmental Response, Compensation and Liability Act (CERCLA), or part of RCRA
corrective action intended to cleanup such contamination; and, the cleanup will, upon
completion, be sufficient to protect human health and the environment.
Can treatment prior to injection include adding nutrients or other products
to the contaminated groundwater designed to promote in-situ
bioremediation or other in-situ treatment?
Yes. This approach is consistent with section 3020(b)(2), as long as the hazardous
constituents are substantially reduced, either before injection or as a result of subsequent in-
situ treatment, and the remedy complies with sections 3020(b)(1) and (3). The substantial
reduction should occur in a reasonable period of time (i.e., in a time period consistent with the
CERCLA and/or RCRA remedial decision made for the groundwater) and the overseeing
regulatory agency should consider whether hydraulic containment measures and groundwater
monitoring would be appropriate to ensure protection of the groundwater resource.
Furthermore, stakeholders should be aware that while the RCRA statute could allow for such
injection, you may also have to comply with requirements of State Underground Injection
Control (UIC) programs. Therefore, you should coordinate with your state regulators to obtain,
as necessary, variances, waivers, construction permits, approvals, etc.
Draft Handbook of RCRA Groundwater Policies, Page 35
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What is the role of groundwater use with regard to this groundwater
injection policy?
You should use the to determine the
that need to be achieved either before injection or after injection when it is part of an in-situ
remediation system.
What if I want to inject groundwater that is contaminated with non-
hazardous wastes as part of my RCRA corrective action?
If the groundwater is not contaminated with hazardous wastes then the ban on injecting
hazardous wastes described in RCRA Section 3020(a) does not apply to you. However, you
should talk with your state regulator because many states have strict groundwater protection
laws that could prohibit the injection of any waste, regardless of whether it is hazardous or not.
Additionally, the remedy involving injection should be consistent with the EPA's
when the injection is part of a interim action; and, when the injection is
part of a final remedy, the injection should be consistent with EPA's
Key References:
EPA, 2000. Applicability of RCRA Section 3020 to In-Situ Treatment of Ground Water.
Memorandum from Elizabeth Cotsworth, Director, Office of Solid Waste to RCRAJJenior Policy
Advisors (April or May). Wll be available when finalized at
.
EPA, 1999a. Matthew Hale, Deputy Office Director, Office of Solid Waste to Peggy Harris,
Chief of Standardized Permitting Section, California Hazardous waste Permitting Program
(December 10). Available at
f88525684800588ea8?OpenDocument
EPA, 1989a. OSWER Directive 9234.1-06, "Applicability of Land Disposal Restrictions to
RCRA and CERCLA Groundwater Treatment Reinjection Superfund Management Review:
Recommendation No. 26," (November 27).
Draft Handbook of RCRA Groundwater Policies, Page 36
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Performance Monitoring
(Updated 4/20/00)
Why do facilities need to conduct performance monitoring?
Facilities should conduct performance monitoring to evaluate whether the facility is achieving
or
What should the performance monitoring accomplish?
Facilities should design performance
monitoring programs to:
Demonstrate that the remedy is
performing according to
expectations;
Detect changes in environmental
conditions (e.g., hydrogeologic,
geochemical, microbiological, or
other changes) that may reduce the
efficacy of the remedy;
Identify any potentially toxic and/or
mobile transformation products;
Verify that the plume(s) is not
expanding above levels of concern
(either downgradient, laterally or
vertically);
Verify no unacceptable impact to
down gradient receptors;
Detect new releases of
contaminants to the environment
that could impact the effectiveness
of the remedy;
Demonstrate the effectiveness of
institutional controls that were put in place to protect potential receptors; and
Verify attainment of short-term protectiveness or final remediation goals.
What should a performance monitoring program include?
The performance monitoring program should specify the location, frequency, and type and
quality of samples, techniques and measurements. It should also specify the methods (e.g.,
statistical analysis) that will be used to evaluate the data and support decision making. The
performance monitoring program should also include interim milestones to demonstrate
progress toward meeting or
How often should facilities monitor?
The frequency of monitoring should be adequate to detect, in a timely manner, the potential
changes in facility conditions listed above. This means that the rate of groundwater flow and
contaminant movement is an important factor to consider when you determine monitoring
Rationale
for Performance Monitoring
Properly designed performance monitoring
programs are especially important for
groundwater remediation because the
concentration and distribution of contamination
in the subsurface often change with time.
Likewise, natural and human factors (e.g.,
seasonal precipitation or nearby groundwater
usage) can influence the ability of remediation
systems to control migration of contaminated
groundwater.
For groundwater remediation systems,
performance monitoring can assess changes in
subsurface conditions so that facilities can
modify the remedy to ensure maximum
efficiency and protectiveness (e.g., by modifying
the location and pumping rate at individual
extraction wells).
Draft Handbook of RCRA Groundwater Policies, Page 37
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frequency. The monitoring plan should include flexibility for adjusting the monitoring
requirements over the life of the remedy. For example, it may be appropriate to decrease the
monitoring frequency and number of constituents at some point in time, once it has been
determined that the remedy is progressing as expected and very little change is observed from
one sampling round to the next. In contrast, the monitoring frequency may need to be
increased if unexpected conditions (e.g., plume migration or change in groundwater use) occur
or to determine the effect of modifications to a interim or final remedy (e.g., changes in
pumping rates).
How do I decide a remedy is working?
Facilities should conduct periodic reviews of performance monitoring results to evaluate
remedy effectiveness towards meeting short-term protectiveness goals or final remediation
goals. If a remedy is not achieving interim milestones, facilities should consider modifying the
remedy design or operation.
How long should performance monitoring continue?
Facilities should generally continue performance monitoring for a specified period after the
facility achieves Extending the performance monitoring to this point in
time helps to verify that the facility no longer poses a threat to human health or the
environment.
What is the role of groundwater use in long-term performance monitoring?
Performance monitoring requirements may need to be more stringent when individuals use the
groundwater at or near the facility, or when other actual or potential exposures to human or
ecological receptors exist. Monitoring requirements may need to be changed if the
groundwater use changes during the remediation period.
Key Reference:
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/Mav/Dav-01/pr-547.pdf. Particularly
relevant pages: 19452-53.
Draft Handbook of RCRA Groundwater Policies, Page 38
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Completing Groundwater Remedies
(Update 4/20/00)
When does EPA consider groundwater remediation to be complete?
EPA considers corrective action for groundwater to be complete when all releases to
groundwater of hazardous waste and hazardous constituents, including releases from solid
waste management units, have been remediated as necessary to achieve: (1)j|horMerm
(2)jfjnah^mediation_goal; (3) and (4)
any facility-specific standards or requirements established by the EPA Regional Administrator
or the appropriate individual in an EPA authorized state program.
What documentation do I need?
Facilities should provide documentation which
demonstrates that either:
(1)
releases and potential releases of
hazardous waste and hazardous
constituents at the facility to groundwater
are non-existent or do not pose
unacceptable risks to human health or
the environment; or
(2)
Rationale
for Completing
Groundwater Remedies
If a remedy meets all of the groundwater
cleanup objectives and EPA's final
remediation goal, then no further action is
required to protect human health and the
environment from releases to groundwater.
the facility has properly and completely
implemented the groundwater remedy
and achieved the
(i.e.,
have been met at the ggjnt_of
compliance), including any facility-specific requirements or standards established by the
regulators.
What is the role of groundwater use in demonstrating completion?
Groundwater cleanup objectives are based on the current use and the use
and should be met in order to demonstrate completion of groundwater remedies.
If the groundwater use designation changes or new exposures to groundwater contamination
occur during the implementation of a remedy, then the stakeholders should re-evaluate the
groundwater cleanup objectives to ensure that the current conditions are protective under the
new designation or exposure.
Key Reference:
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
Particularly
relevant page: 19453.
Draft Handbook of RCRA Groundwater Policies, Page 39
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References
EPA, 2000. Applicability of RCRA Section 3020 to In-Situ Treatment of Ground Water.
Memorandum from Elizabeth Cotsworth, Director, Office of Solid Waste to RCRAJJenior Policy
Advisors (April or May). Wll be available when finalized at
.
EPA, 1999a. Matthew Hale, Deputy Office Director, Office of Solid Waste to Peggy Harris,
Chief of Standardized Permitting Section, California Hazardous waste Permitting Program
(December 10). Available at
f88525684800588ea8?QpenDocument
EPA, 1999b. Corrective for Solid Waste Management Units at Hazardous Waste Management
Facilities (64 FR 54604, October 7). Available at
http://www.epa.gov/epaoswer/hazwaste/ca/partwith.htm.
EPA, 1999c. Safe Drinking Water Act, Section 1429 Groundwater Report to Congress. EPA-
816-R-99-016; October, 1999. Available at .
EPA, 1999d. RCRA Cleanup Reforms (EPA530-F-99-018; July 1999). For more information,
refer to httg^/www^ega^gpj/Tre^
EPA, 1999e. Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action and
Underground Storage Tank Sites (April 21). OSWER Policy Directive 9200. 4-1 7P. Available
at M|x//wA/wyj^ Other helpful links regarding MNA
available at http://www.epa.gov/swerust1/mna/index.htm and
http://www.epa.gov/swerust1/oswermna/mnalinks.htm .
EPA, 1999f. Interim Final Guidance for RCRA Corrective Action Environmental Indicators
(February 5). Available at ....... guida.pdf .
EPA, 1998a. RCRA Orientation Manual (EPA530-R-98-004). Available at
http://www.epa.gov/epaoswer/general/orientat/index.htm .
EPA, 1998b Plain Language in Government Writing (June 1). Available at
http://www.npr.gov/library/direct/memos/memoeng.html .
EPA, 1998c. Memorandum from Elizabeth Cotsworth to RCRA Senior Policy Advisors titled,
Risk-Based Clean Closure (March 16). Available at
.
EPA, 1998d. Standards Applicable to Owners and Operators of Closed and Closing
Hazardous Waste Management Facilities: Post-Closure Permit Requirement
and Closure Process; Final Rule (63 FR 56710). Available at
.
EPA, 1997a. Memorandum from Elliott P. Laws and Steven A. Herman to RCRA/CERCLA
Senior Policy Managers titled, "Use of the Corrective Action Advance Notice of Proposed
Rulemaking as Guidance" (January 17). Available at www. _ .
Draft Handbook of RCRA Groundwater Policies, Page 40
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EPA, 1997b. Rules of Thumb for Superfund Remedy Selection (EPA 540-R-97-013).
Available at .
EPA, 1997c. State Source Water Assessment and Protection Programs Guidance (August).
Available at
EPA, 1997d. The Role of Comprehensive State Groundwater Protection Programs
(CSGWPPS) is OSWER Remediation Programs. OSWER Directive 9283.1-09. Available at
.
EPA, 1996a. Advance Notice of Proposed Rulemaking (61 FR 19432, May 1). Available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/Mav/Dav-01/pr-547.pdf.
EPA, 1996b. Memorandum from Steven A. Herman and Elliott P. Laws to RCRA/CERCLA
Senior Policy Managers titled, "Coordination between RCRA Corrective Action and Closure
and CERCLA Site Activities" (September 24). Available at
http://www.epa.gov/swerffrr/doc/924memo.htm.
EPA, 1993. Guidance for Evaluating the Technical Impracticability of Groundwater Restoration
EPA/540-R-93-080, (September). Available at
http://www.epa.gov/oerrpage/superfund/resources/gwdocs/techimp.htm
EPA, 1992. Final Comprehensive State Groundwater Protection Program Guidance, EPA
10O-R-93-001. For more information, refer to www.epa.gov/OGWDW/Pubs/06ground.html.
EPA, 1991 a. Managing the Corrective Action Program for Environmental Results: The RCRA
Stabilization Effort (October 25). Available at
.
EPA, 1991b. Protecting the Nation's Groundwater: EPA's Strategy for the 1990's. Office of
the Administrator. Washington, D.C. For more information, refer to
http://www.epa.gov/OGWDW/Pubs/11 ground.html .
EPA, 1991c. A Guide to Principal Threats an Low Level Threat Wastes. Superfund
Publication 9380.3-06FS (November). Available at
.
EPA, 1989a. OSWER Directive 9234.1-06, "Applicability of Land Disposal Restrictions to
RCRA and CERCLA Groundwater Treatment Reinjection Superfund Management Review:
Recommendation No. 26," (November 27).
EPA, 1989b. National Priorities List for Uncontrolled Hazardous Waste Sites - Final Rule
Covering Sites Subject to the Subtitle C Corrective Action Authorities of the Resource
Conservation and Recovery Act (commonly referred to as the RCRA Deferral Policy).
Available in Section V which appears on 54 FR 41004-41006 (October 4).
EPA, 1988. OSWER Directive 9283.1-2, "Guidance on Remedial Actions for Contaminated
Groundwater at Superfund Sites," (December 1).
Draft Handbook of RCRA Groundwater Policies, Page 41
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EPA, 1987. Alternate Concentration Limit Guidance (EPA/530-SW-87017).
EPA, 1986. Guidelines for Ground-water Classification under the EPA Ground-Water
Protection Strategy".
Draft Handbook of RCRA Groundwater Policies, Page 42
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Appendix 1
How is the RCRA Corrective Action Program Implemented?
The RCRA Corrective Action Program evaluates releases of hazardous wastes and hazardous
constituents from hazardous waste treatment, storage and disposal facilities, and develops
and guides facilities in facility-wide cleanups to protect human health and the environment.
Currently, EPA believes that there are approximately 6,400 facilities subject to RCRA
corrective action. Of these, approximately 3,700 facilities have corrective action already
underway or will need to implement corrective action as part of the process to obtain a permit
to treat, store or dispose of hazardous waste. EPA established specific goals for 1,714
facilities that warrant attention in the near term. These goals correspond to two
"Environmental Indicators" that are described in more detail under the policy for Short-Term
Protectiveness Goals in this Handbook.
RCRA corrective action is implemented by both EPA and the States. At present, there are 33
states and territories authorized by EPA to carry out RCRA corrective action. EPA or States
use a variety of mechanisms such as permits, orders or voluntary agreements to accomplish
investigation and cleanup of contamination at corrective action facilities. Under RCRA
corrective action authorities, facilities pay for and conduct the investigation and cleanup
activities, and the regulators oversee the activities to ensure that the facility performs the work
properly.
EPA's authority to require facility-wide corrective action comes from the RCRA statute.
Specific sections of that statute that can require corrective action (or aspects of corrective
action) include: 3004(u)&(v), 3005(c)(3), 3008(h), 3013, and 7003, EPA's regulatory authority
for corrective action at permitted facilities is found in 40 CFR Part 264 Subpart F. EPA
provided additional direction through guidance, policy directives and related regulations all of
which were designed to increase the effectiveness and efficiency of corrective action. The
most recent and comprehensive guidance issued for RCRA corrective action is included in the
May 1, 1996 Advance Notice of Proposed Rulemaking (ANPR, 61 FR 19431, available at
http://www.epa.gov/docs/fedrgstr/EPA-WASTE/1996/iyav/Dav-01/pr-547.pdf).
Draft Handbook of RCRA Groundwater Policies, Page 43
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Appendix 2 - Glossary
area of attainment - defines the area over which cleanup levels will be achieved in
groundwater. It encompasses the area outside the boundary of any waste remaining in place
and up to the boundary of the contaminant plume. Generally, if the source area is removed,
the entire plume is within the area of containment. On the other hand, if waste is left in place
as part of a final remedy, the groundwater beneath the waste management area
encompassing the source(s) is not within the area of attainment. Cleanup levels should be
achieved throughout the area of attainment. This definition of area of containment is
synonymous with the phrase "point of compliance" used for facility-wide RCRA Corrective
Action. (Source- EPA, 1988)
aquifer - a water-bearing layer of rock or sediment capable of yielding supplies of water;
typically is unconsolidated deposits or sandstone, limestone or granite. Can be classified as
confined or unconfined.
Comprehensive State Groundwater Protection Program (CSGWPP) - a groundwater
management strategy developed by a State. EPA reviews CSGWPPs and "endorses" those
that successfully meet six strategic activities. EPA established recommended adequacy
criteria for each strategic activity in CSGWPP guidance. In particular, EPA remediation
programs review State guidelines in the CSGWPP to prioritize groundwater based upon use,
value and vulnerability. In 1997, EPA's Office of Solid Waste and Emergency Response
issued a directive encouraging EPA's remediation programs to defer, where appropriate, to
State determinations of current and future use when based on an EPA-endorsed CSGWPP
that has provisions for facility-specific decisions. (Source - EPA, 1992)
cleanup - The term "cleanup" or the phrase "cleaning up" refers to the range of activities that
could occur in the context of addressing environmental contamination at RCRA facilities. For
example, cleanup activities could include removing waste or contaminated media (e.g.,
excavation, pumping groundwater, etc.), in-place treatment of the waste or contaminated
media (e.g., bioremediation), containment of the waste or contaminated media (e.g., barrier
walls, low-permeable covers, liners, etc.), or various combinations of these approaches. The
term cleanup is often used interchangeably with the term remediate.
groundwater - water occurring in the zone of saturation in an aquifer or soil.
- a determination of reasonably anticipated use, resource value
(e.g., priority), and/or vulnerability of groundwater in a particular area.
-Groundwater cleanup levels are facility-specific chemical
concentrations in groundwater that a final remedy should achieve for the remedy to be
considered complete.
- Groundwater cleanup objectives include three
components: of and
maximum beneficial groundwater use - Wthin the range of reasonably expected uses, the
maximum (or highest) beneficial groundwater use is the one which that warrants the most
stringent groundwater cleanup levels.
Draft Handbook of RCRA Groundwater Policies, Page 44
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- The term "monitored natural attenuation" refers to an
approach to clean up environmental contamination by relying on natural processes. Natural
attenuation processes include a variety of physical, chemical, or biological processes that,
under favorable conditions, act without human intervention to reduce the mass, toxicity,
mobility, volume or concentration of contaminants in groundwater. (Source - EPA, 1999e)
principal threats - Source materials considered to be highly toxic or highly mobile that
generally cannot be reliably contained or would present a significant risk to human health or
the environment should exposure occur. (Source - EPA, 1991c)
of - The point of compliance for groundwater, in the context of RCRA
corrective action, represents where the facility should meet within
a contaminated aquifer at the conclusion of a final remedy (i.e., the facility has achieved its
The groundwater point of compliance for RCRA Corrective Action
should be throughout the area where groundwater is contaminated above the cleanup level(s),
or, when waste is left in place, at and beyond the boundary of the waste management area
encompassing the original source(s) of groundwater contamination.
- The remediation time frame for groundwater is the facility-specific
schedule for a groundwater remedy. It includes the time frame to construct the remedy and an
estimate of the time frame to achieve at the
RCRA Regulated Units - Regulated units are defined in 40 CFR 264.90 as surface
impoundments, waste piles, land treatment units, and landfills that received hazardous waste
after July 26, 1982.
- Source control refers to a range of actions (e.g. removal, treatment in place,
containment, etc.) designed to protect human health and the environment from sources of
contamination.
source materials - Source material is defined as material that includes or contains hazardous
substances, pollutants or contaminants that act as a reservoir [either stationary or mobile] for
migration of contamination to groundwater, to surface water, to air, [or other environmental
media], or acts as a source for direct exposure. Contaminated groundwater generally is not
considered to be a source material although non-aqueous phase liquids (NAPLs [occurring as
residual or free-phase]) may be viewed as source materials. (Source - EPA, 1991c).
- Technical impracticability (Tl) refers to a situation where achieving
is not possible from an "engineering perspective." The phrase
"engineering perspective" refers to how factors such as feasibility, reliability, scale and safety
influence the ability to achieve groundwater cleanup objectives. (Source - EPA, 1993)
Note to reviewers of draft: Please identify additional terms you'd like to see included in this
glossary.
Draft Handbook of RCRA Groundwater Policies, Page 45
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Appendix 3 -
Key EPA Regional Contacts and Internet Addresses
Draft Handbook of RCRA Groundwater Policies, Page 46
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