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Superfund Groundwater: Groundwater Response Selection

On this page you can find guidance and documents related to Groundwater Response Selection for Superfund sites.

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Summary of Key Existing EPA CERCLA Policies for Groundwater Restoration (June 26, 2009) OSWER Directive 9283.1-33 (PDF)(12 pp, 2520 K, About PDF)
This Directive provides a compilation of some key existing EPA ground water policies to assist EPA Regions in making groundwater restoration decisions pursuant to CERCLA and the NCP.  It addresses:

  • Whether CERCLA remedial action is warranted
  • Appropriate role of institutional controls (ICs)
  • Groundwater classification and beneficial use policy
  • Remedial action cleanup levels
  • Groundwater point of compliance

On this page:

Alternative Water Supply

Update on Providing Alternative Water Supply as Part of Superfund Response Actions (September 24, 2010) OSWER Directive 9355.3-22 (PDF)(8 pp, 4.5 MB)
This memorandum modifies the existing 1988 guidance by no longer recommending the use of two types of alternative water supply options described in that guidance, specifically oversized community storage facilities to compensate for loss of existing system capacity in emergency demand situations and blending of new and existing water supplies to achieve acceptable levels. This memorandum does, however, reaffirm the six recommended ways that alternative water supplies can be provided for remedial actions, as described in the NCP, and reaffirms existing interpretations of the NCP for removal actions. This memorandum also provides a summary of the number of remedial and removal actions that included alternative water supplies and the number of people protected by those alternative water supplies.

Guidance Document for Providing Alternate Water Supplies (February 1988) OSWER Directive 9355.3-03, EPA/540/G-87/006 (PDF)(71 pp, 2MB)
This guidance was written to help response managers plan and implement alternate water supplies at uncontrolled hazardous waste sites where the action can be done under a Non-Time Critical Removal Action or an Operable Unit (or “early”) Remedial Action. It does not address alternate water supplies implemented under Time-Critical Removal Actions or as a normal part of a final Remedial Action. The document provides guidance on determining if an alternate water supply is needed, and if needed, on selection and implementation of alternate water supplies. It includes provision of new supplies and treatment or redistribution of existing supplies. Appendix C on EPA Standards and Appendix D on Removal Action Levels have been superseded by more recent standards and guidance.

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Applicable or Relevant and Appropriate Requirements (ARARs) for Ground Water Cleanups

Applicability of RCRA Section 3020 to In-Situ Treatment of Groundwater, Exit December 27, 2000, OSWER/OSW Memorandum (PDF) (6 pp, 388 K)
Attachment: Applicability of Land Disposal Restrictions to RCRA and CERCLA Groundwater Treatment Reinjection Superfund Management Review: Recommendation No. 26 December 27, 1989. OSWER Directive 9234.1-06 (PDF) (3 pp, 317 K)
This memorandum clarifies that reinjection of treated ground water to promote in-situ treatment is allowed under section 3020(b) as long as certain conditions are met. Specifically, the ground water must be treated prior to reinjection; the treatment must be intended to substantially reduce hazardous constituents in the ground water - either before or after reinjection; the cleanup must be protective of human health and the environment; and the injection must be part of a response action under CERCLA section 104 or 106 or a RCRA corrective action intended to clean up the contamination.

Applicability of Land Disposal Restrictions to RCRA and CERCLA Groundwater Treatment Reinjection Superfund Management Review: Recommendation No. 26 December 27, 1989. OSWER Directive 9234.1-06 (PDF) (3 pp, 317 K)
This memorandum explains EPA's interpretation of whether the RCRA land disposal restrictions (LDRs) are applicable or (under CERCLA response actions only) relevant and appropriate to such reinjections or to the remediation as a whole. There has been some question as to whether ground water contaminated with restricted RCRA hazardous wastes, which is extracted during a RCRA corrective action or CERCLA response action, must meet the best demonstrated available technology (BDAT) identified for that waste under the RCRA LDRs prior to each reinjection, in a pump-and-treat reinjection remediation system.

Clarification of the Role of Applicable, or Relevant and Appropriate Requirements in Establishing Preliminary Remediation Goals Under CERCLA, August 1997, OSWER Directive 9200.4-23 (PDF) (4 pp, 411 K)
This memo clarifies the relationship between ARARs and protectiveness.

Permits and Permit 'Equivalency' Processes for CERCLA On-site Response Actions, February 1992, OSWER Directive 9355.7-03 (PDF)(7 pp, 45 K)
Clarifies the EPA policy on ARARs with respect to attaining permits for activities at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites.

ARARs Q & A's

CERCLA Compliance with Other Laws Manual: Part I, Interim Final, August 1988, OSWER Publication 9234.1-01(PDF)(243 pp, 1.84 MB)
CERCLA Compliance with Other Laws Manual: CERCLA Compliance with the CWA and SDWA Fact Sheet (February 1990) OSWER 9234.2-06FS, (PDF)(7 pp, 688 K)
Section 121(d) of CERCLA requires that on-site remedial actions attain or waive Federal or more stringent State applicable or relevant and appropriate requirements (ARARs) upon completion of the remedial action. The 1990 National Oil and Hazardous Substances Pollution Contingency Plan requires compliance with ARARs during remedial actions as well, and during removal actions to the extent practicable. This volume covers potential ARARs of the Resource Conservation and Recovery Act (RCRA), Clean Water Act (CWA), Safe Drinking Water Act (SDWA), Clean Air Act (CAA), and other laws as required by CERCLA. The 1990 fact sheet provides a guide to Chapters 3 and 4 of Part I of the "CERCLA Compliance with Other Laws Manual." The fact sheet focuses on CERCLA compliance with the Clean Water Act (Chapter 3) and Safe Drinking Water Act (Chapter 4), and discusses other statutes with provisions relevant to surface water or drinking water.

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Technical Impracticability

This page provides information to support and inform decisions related to Technical Impracticability (TI).

Clarification of the Consultation Process for Evaluating the Technical Impracticability of Groundwater Restoration at CERCLA Sites, December 28, 2016, OLEM Directive 9200.3-117 (PDF) (20 pp, 628 KB)
This Directive is an extension of the original 1993 OSWER Directive (9234.2-25) Guidance for Evaluating the Technical Impracticability (TI) of Ground-Water Restoration, which contained overarching TI guidance and the subsequent 1995 OSWER Directive (9200.4-14) Consistent Implementation of the FY 1993 Guidance on Technical Impracticability of Ground-Water Restoration at Superfund Sites.

The six documents in this TI package are designed to help:

  • Promote national consistency in TI decision making;
  • Facilitate transfer of information pertinent to TI decisions between Headquarters and the regions;
  • Identify the appropriate persons to conduct reviews of TI-related documents; and
  • Clarify the role of Headquarters consultation.

Summary of Technical Impracticability Waivers at National Priorities List Sites, August 2012, OSWER Directive 9230.2-24(PDF)(101 pp, 1.7 MB)
The purpose of this report is to provide a summary of TI waivers that have been issued by EPA's Regional offices, and to distribute brief summaries of completed TI waiver decisions, including a summary of the site conditions and the Regions' rationale for adopting a TI waiver.

Clarification of OSWER's 1995 Technical Impracticability Waiver Policy, September 2011, OSWER Directive 9355.5-32 (PDF) (4 pp, 764 K)
The purpose of this memorandum is to provide clarification to the memorandum titled, Superfund Groundwater RODs: Implementing Change This Fiscal Year, July 31, 1995, (OSWER Directive 9335.3-03P) regarding the use of TI waivers at Comprehensive Environmental Response Compensation and Liability Act (CERCLA) sites with Dense Non-Aqueous Phase Liquid (DNAPL) contamination.

Superfund Groundwater RODs: Implementing Change This Fiscal Year, July 1995, OSWER 9335.5-03P, EPA 540-F-99-005(2 pp, 33 K)
Discusses the importance of consistent national implementation of policies concerning sites with groundwater contamination. Emphasizes that TI waivers will generally be appropriate for sites where restoration of groundwater to drinking water standards is technically impracticable. This document was updated by September 19, 2011 document titled "Clarification of OSWER's Technical Impracticability Waiver" (OSWER Directive 9355.5-32).; The September 2011 document states: 1) the 1995 memorandum was intended to apply only to remedy decisions made in Fiscal Year 1995 and 2) DNAPL contamination in and of itself should not be the sole basis for considering the use of a TI waiver."

Consistent Implementation of the FY 1993 Guidance on Technical Impracticability of Groundwater Restoration at Superfund Sites, January 19, 1995, OSWER Directive 9200.4-14 (PDF) (7 pp, 388 K)
Clarifies the role of EPA Headquarters in groundwater Technical Impracticability decisions. Emphasizes that these decisions should be made as soon in the Superfund process as sufficient information is available.

Guidance for Evaluating Technical Impracticability of Groundwater Restoration September, 1993, OSWER Directive 9234.2-25 (PDF) (27 pp, 2.4 MB)
This interim final guidance clarifies how EPA will determine whether groundwater restoration at Superfund and RCRA sites is technically impracticable and if so, what alternative measures must to undertaken to ensure that a final remedy is protective. Topics include the types of technical data needed, the criteria for decisions, the types of documentation needed, and alternative remedial strategies for sites with dense non-aqueous phase liquids (DNAPLs).

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Remedy Selection/Decision Documents

Use of Monitored Natural Attenuation for Inorganic Contaminants in Groundwater at Superfund Sites, August 2015, Final OSWER Directive 9283.1-36 (PDF) (83 pp, 1.3 MB)
This new monitored natural attenuation (MNA) policy document for inorganic contaminants ("2015 MNA guidance") expands on and is designed to be a companion to the 1999 MNA guidance. Together, these two policy documents provide guidance on the consideration of MNA for a broad range of contaminants at Superfund sites. This 2015 MNA guidance, consistent with the 1999 MNA guidance, indicates that multiple "lines of evidence" should be obtained to evaluate whether MNA should be considered as part of the site's selected response action. As a related matter, the 1999 MNA guidance also recommends use of a tiered analysis approach for considering MNA, which typically involves a detailed analysis of site characteristics that control and sustain attenuation. The 2015 MNA guidance builds on this tiered approach and recommends a phased analytical approach tailored specifically for inorganic contaminants.

Alternate Concentration Limits (ACLs) in Superfund Cleanups, July 19, 2005, OSWER Directive 9200.4-39 (PDF)(4 pp, 341 K)
This memorandum provides EPA policy related to the use of CERCLA ACLs in Superfund cleanups and supersedes any previous guidance on this matter. CERCLA section 121 provides authority to use ACLs under certain circumstances. This memorandum reiterates the statutory requirements and provides several factors to consider in evaluating whether use of CERCLA ACLs may be appropriate under site-specific circumstances.

Alternate Concentration Limit Guidance, Interim Final, July 1987, OSWER Directive 9481.00-6C, EPA530-SW-87-017 (PDF)(127 pp, 4.5 MB)
This document provides guidance to RCRA facility permit applicants and writers concerning the establishment of RCRA Alternate Concentration Limits (RCRA ACLs). The guidance lists 19 factors, or criteria, that are used to evaluate ACL requests.
Caution: Information in this document cannot be applied to Superfund sites because the CERCLA statute placed several limitations on the use of ACLs in Superfund remedies (see Alternate Concentration Limits (ACLs) in Superfund Cleanups, OSWER Directive 9200.4-39, above).

Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other Remedy Selection Decision Documents,  July 1999, OSWER Memorandum 9200.1-23P, EPA540-R-98-031 (PDF) (182 pp, 2.9 MB)
This updated guidance on writing Records of Decision (RODs), Explanations of Significant Difference (ESDs) and ROD amendments includes sections on documenting all types of ground water remedy decisions and technical impracticability waivers, including sample language.

How this document relates specifically to groundwater:

  • Section 9.4 provides specific guidance to documenting ground water decision responses.
  • Section 9.5 provides guidance on documenting Technical Impracticability (TI) waivers.
  • Attachment A provides a sample Proposed Plan that deals with ground water contamination among other media. Attachment B provides information on documenting special groundwater remedy decisions such as the phase approach.

Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites, April 1999, Final OSWER Directive, Publication EPA540-R-99-009 (PDF) (39 pp, 1.9 MB)
This directive clarifies EPA's policy regarding the use of monitored natural attenuation (MNA) for the remediation of contaminated soil and groundwater. It defines the term "monitored natural attenuation" and explains that EPA considers it a remedy, not a "no action" alternative. The directive outlines potential advantages and disadvantages of this remedy, under what conditions it should be selected, the type of site most suitable for this remedy choice, the site data required to support the decision, performance monitoring considerations, and the use of contingency remedies. The directive also has a lengthy bibliography, including EPA web sites with information on monitored natural attenuation.

Rules of Thumb for Superfund Remedy Selection, August 1997, OSWER Publication 9355.0-69, EPA 540-R-97-013 (PDF) (27 pp, 152 K)
This guidance describes key principles and expectations, interspersed with "best practices" based on program experience that should be consulted during the Superfund remedy selection process. Three major policy areas are covered: risk; remedial alternatives; and groundwater. The guidance summarizes key elements of other guidance documents in these areas and provides citations for other EPA guidances an RPM may need to consult for more detailed information.

Superfund Reforms: Updating Remedy Decisions, OSWER Memorandum 9200.0-22, EPA540-F-96-026, September 27, 1996
This memo explains the purpose of the reform, the types of remedy updates anticipated, and the process for updating remedies. It includes specific detail about how the reform relates to groundwater remedies, especially with regard to remedy updates which 1. Change the remediation technology, 2. Reconsider remedial objectives, or 3. Reduce monitoring data needs.

A Guide to Principal Threat and Low Level Threat Wastes, November 1991, OSWER Publication 9380.3-06FS (PDF) (4 pp, 236 K)
This guidance explains considerations that should be taken into account in categorizing waste for which treatment or containment generally will be suitable and provides definitions, examples, and Record of Decision (ROD) documentation requirements related to waste that constitute a principal or low level threat. It explains that the concept of principal threat is to be applied when characterizing source material and that contaminated ground water is not generally considered to be a source material, although non-aqueous phase liquids (NAPLs) may be viewed as source materials.

A Guide on Remedial Actions for Contaminated Groundwater (Fact Sheet), April 1989, OSWER Directive 9283.1-2FS (PDF) (5 pp, 101 K)
This fact sheet summarizes key issues in the development, evaluation, and selection of groundwater remedial actions at Superfund sites. It provides a short summary of CERCLA requirements, project planning, remedial action objectives, types of response actions, evaluating performance, and a multiple source strategy. For more detail on this topic, see December 1988, "Guidance on Remedial Actions for Contaminated Groundwater at Superfund Sites", below. Use of either document should be augmented by more recent guidance.

Guidance on Remedial Actions for Contaminated Groundwater at Superfund Sites, December 1988, OSWER Directive 9283.1-2, EPA540-G-88-003 (PDF)(121 pp, 1.8 MB)
This guidance summarizes policy issues and the decision-making approach to developing, evaluating, selecting, and implementing groundwater remedial actions at Superfund sites. It should be supplemented by reference to more recent guidance on specific topics, but is still a useful overview. It includes practical appendices on: a case study, multiple source plume issues, interim action RODs for groundwater, and equations for estimating restoration time-frame.

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Phased Ground Water Cleanup Approach

Presumptive Response Strategy and Ex-Situ Treatment Technologies for Contaminated Groundwater at CERCLA Sites, Final Guidance, October 1996, OSWER Directive 9283.1-12 (PDF) (86 pp, 779 K)
This guidance outlines the "phased approach" strategy for addressing contaminated groundwater. The strategy integrates the site characterization, early actions, remedy selection, design, implementation, and performance monitoring phases. The strategy emphasizes ways to select achievable remedial objectives and ways to optimize the selected remedy so that it is more effective, less costly, and takes less time. The guidance also identifies presumptive technologies for treatment of extracted groundwater, which are to be used to streamline the Feasibility Study for sites which evaluate pump and treat remedies.

Considerations in Groundwater Remediation at Superfund Sites and RCRA Facilities - Update, May 27, 1992, OSWER Directive 9283.1-06 (PDF) (13 pp, 76 K)
This directive clarifies and expands OSWER's general policy concerning remediation of contaminated groundwater, especially with regard to nonaqueous phase liquid (NAPLs) contaminants. It summarizes actions that should be included at sites with NAPL involving site investigation, early or interim actions, and remedy implementation, including findings of Technical Impracticability.

Suggested ROD Language for Various Groundwater Remediation Options, October 10, 1990, OSWER Directive 9283.1-03 (PDF) (9 pp, 52 K)
This directive provides guidance for Superfund Records of Decision (RODs) concerning groundwater. The guidance recommends remedies be defined as final actions where there is little uncertainty that the remedy will be able to achieve remediation goals; contingency measures or goals where there is high to moderate uncertainty, potential applicable or relevant and appropriate requirements (ARARs) waivers, or a potential containment goal; and interim actions where there is moderate to substantial uncertainty or early action containment measures. The guidance includes sample ROD language for all options.

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Groundwater Removal Actions

Numeric Removal Action Levels for Contaminated Drinking Water Sites, November 10, 1998, OSWER Memorandum 9360.1-02B-P, EPA-540-F99-004 (PDF)  (16 pp, 83 K)
This memo transmits the table of Removal Action Levels (RALs), dated April 1997. The tables are provided as a convenience to response managers and are intended to be used as one factor in determining whether to provide alternate water supplies under Superfund removal authority. For substances not listed in the RAL table, response managers should refer to the methodology outlined in OSWER Directive 9360.1-02, dated October 1993, to derive a number.

Final Guidance on Numeric Removal Action Levels for Contaminated Drinking Water Sites, October 25, 1993, OSWER Directive 9360.1-02 (PDF)  (27 pp, 1.32 MB)
This Directive includes the final Office of Superfund Remediation and Technology Innovation methodology and guidance on calculation of numeric removal action levels (RALs), to assist Superfund personnel in deciding whether to provide alternate sources of drinking water to populations adversely affected by releases of hazardous substances into the environment. The RAL tables attached to this guidance were updated in September 1995, March 1995, and most recently in April 1997 (retransmitted November 1998). The tables are a convenience only; RALs for additional constituents may be derived using the methodology provided in this guidance.

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Groundwater Use Determinations

The Role of CSGWPPs in EPA Remediation Programs, April 4, 1997, OSWER Directive 9283.1-09 (PDF) (13 pp, 235 K)
This directive establishes and explains the policy that EPA remediation programs generally should defer to State determinations of current and future groundwater uses when based on an EPA-endorsed Comprehensive State Groundwater Protection Program (CSGWPP). This directive also provides background information on CSGWPPs.

Final Comprehensive State Groundwater Protection Program Guidance, December 1992, U.S. EPA Office of the Administrator Publication EPA100-R-93-001  (166 pp, 850 KB)
This guidance provides guidance to States on preparing Comprehensive State Ground Water Protection Programs with the goal of coordinating groundwater protection across programs and providing additional flexibility to States in directing their groundwater activities. The guidance defines EPA's three-tiered hierarchy of preferred groundwater protection objectives (prevention wherever possible; prevention based on vulnerability, use and value; remediation based on relative use and value.) The guidance also outlines State linkages to EPA and other Federal programs which relate to groundwater.

Guidelines for Groundwater Classification Under the [1984] EPA Groundwater Protection Strategy, Final Draft, November, 1986, Office of Groundwater Protection Publication EPA440-6-86-007 (PDF) (10 pp, 437 K)
These Final Draft guidelines further define the concepts and key terms related to the classification system outlined in the 1984 Groundwater Protection Strategy, and describe procedures and information needs for classifying ground water using this approach. Although the guidelines were not finalized, they are still in current use, as modified by the more recent CSGWPP guidances.

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