These questions and answers are intended to assist users in coordinating federal agency compliance with Section 106 of the NHPA (54 U.S.C. § 306108) when an agency proposes to conduct on-site CERCLA removal or remedial actions.

1. What is CERCLA?
2. To what extent must an agency consider other laws before a CERCLA removal or remedial action? What does Section 106 require?
3. When would Section 106 apply to a CERCLA removal or remedial action?
4. How does a federal agency meet the substantive requirements of Section 106 for a proposed response action?
5. Is consultation with the SHPO/THPO/Indian tribes and other parties a substantive requirement of Section 106?
6. Is a separate public outreach process required when coordinating Section 106 and CERCLA actions?
7. When should an agency complete the Section 106 process?

1. What is CERCLA?

CERCLA, commonly known as Superfund, was enacted by Congress on December 11, 1980. This law created a tax on the chemical and petroleum industries and provided broad federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment. CERCLA established prohibitions and requirements concerning closed and abandoned hazardous waste sites; provided for liability of persons responsible for releases of hazardous waste at these sites; and established a trust fund to provide for cleanup when no responsible party could be identified. The law authorizes two kinds of response actions: (1) short-term removals, where actions may be taken to address releases or threatened releases requiring prompt response; and (2) long-term remedial response actions, that permanently and significantly reduce the dangers associated with releases or threats of releases of hazardous substances that are serious, but not immediately life threatening. These actions can be conducted only at sites listed on the Environmental Protection Agency’s (EPA’s) National Priorities List. CERCLA also enabled the revision of the National Contingency Plan (NCP).[1] The NCP provided the guidelines and procedures needed to respond to releases and threatened releases of hazardous substances, pollutants, or contaminants. For more information on CERCLA, please visit the EPA's website.

2. To what extent must an agency consider other laws before a CERCLA removal or remedial action?

Pursuant to the NCP, on-site means “the areal extent of contamination and all suitable areas in very close proximity to the contamination necessary for implementation of the response action.”[2] Generally, for the on-site portion of a CERCLA removal or remedial action, a federal agency must satisfy only the substantive—not the administrative or procedural—requirements of other statutes. This distinction is based on the permit waiver in CERCLA §121(e)(1), and on the definitions of both “applicable requirements” and “relevant and appropriate requirements” (collectively, ARARs) in the NCP (40 CFR § 300.5). Section 106 of the NHPA generally would constitute an ARAR for a federal clean-up response that has the potential to affect historic properties.

For off-site CERCLA response actions, both the procedural and substantive components of other laws may apply. For example, both the procedural and the substantive components of Section 106 would apply to off-site undertakings such as the proposed construction of roads to provide access to the cleanup site or the proposed construction of a staging area.

3. What does Section 106 require?

It is important to keep in mind that Section 106 does not mandate the preservation of historic properties. The protection of historic properties is a public interest that should be considered among other interests, including the clean-up mandate of CERCLA. Section 106 imposes two principal substantive requirements on federal agencies: (1) federal agencies must “take into account” the effects of their undertakings on properties included in or eligible for inclusion in the National Register of Historic Places (hereinafter, “historic properties”); and (2) agencies must afford the Advisory Council on Historic Preservation (ACHP) a “reasonable opportunity to comment” on undertakings that may affect historic properties.[3]

Generally, when a federal agency has an undertaking with the potential to affect historic properties, it follows the regulations set forth at 36 CFR Part 800, which include both substantive and procedural components. As noted above, on-site CERCLA response actions need only meet the substantive requirements of Section 106. The ACHP believes those requirements include identifying historic properties that may be affected by the proposed undertaking, assessing the potential effects to historic properties, and considering ways to avoid, minimize, or mitigate any adverse effects to historic properties. Consultation with the SHPO/THPO, Indian tribes, Native Hawaiian organizations (NHOs),[4] and other consulting parties as appropriate, including the ACHP, is also a substantive requirement of Section 106. As evidenced through the multiple iterations of regulations promulgating the Section 106 process, consultation is an inherent and integral part of an agency’s effort to take into account the effects of the undertaking on historic properties. Consultation provides the agency with necessary information regarding the characteristics of the property that make it historic, the way those characteristics might be affected by a proposed undertaking, and the public interest in how any adverse effects might be avoided, minimized, or mitigated.

In addition to Section 106, Section 110 of the NHPA (54 U.S.C. § 306107) directs agencies to “minimize harm” to any National Historic Landmarks (NHLs) “to the maximum extent possible.” Although this requirement is also substantive, this paper focuses on the routine intersection of Section 106 and CERCLA. Should an agency encounter a situation where a CERCLA action may affect an NHL, the agency should contact the ACHP at the earliest steps to determine an appropriate compliance strategy.

4. When would Section 106 apply to a CERCLA removal or remedial action?

To determine whether a federal agency has an undertaking with the potential to affect historic properties, it should assess the type of response action proposed. If the proposed response action is not the type of activity that would affect historic properties (assuming historic properties were present), then no further Section 106 compliance is necessary.

Where an on-site CERCLA removal or remedial action constitutes an undertaking with the potential to affect a historic property, the agency must satisfy the substantial requirements of Section 106 to “take into account” the potential effects of the undertaking on historic properties and provide the ACHP “reasonable opportunity to comment.” While the agency may elect to follow the Section 106 review process set forth in the procedural steps of 36 CFR Part 800, including 30-day review periods for effect findings and development of a Memorandum of or Programmatic Agreement, these procedural steps are not required.  At a minimum, the agency must only ensure that its CERCLA removal or remedial action process is designed to meet the “take into account” requirement, and to afford the ACHP a “reasonable opportunity to comment” on the proposed response action, specifically, carrying out and consulting on the identification and evaluation of historic properties affected by undertaking; the assessment of effects on identified historic properties; and the consideration of binding measures to avoid, minimize, or mitigate any potential adverse effects to historic properties. This work can be evidenced through the agency’s CERCLA process and documentation.

Where an off-site CERCLA removal or remedial action constitutes an undertaking with the potential to affect a historic property, both the procedural and the substantive components of Section 106 must be met. Where the cleanup includes both on- and off-site components, the ACHP recommends that, when practicable, an agency consider developing a Programmatic Agreement to address the entirety of the action.

5. How does a federal agency meet the substantive requirements of Section 106 for a proposed response action?

The substantive requirements of Section 106 are met by the following:

(1) Identifying and evaluating historic properties that may be affected by the undertaking.

The meaning of “undertaking” does not change under a CERCLA response action and is defined in the NHPA as a project, activity, or program funded in whole or in part under the direct or indirect jurisdiction of a federal agency, including those carried out by or on behalf of the agency, those carried out with federal financial assistance, or those requiring a federal permit, license, or approval. (36 CFR § 800.16(y))

To satisfy the statutory requirement to take into account the effects of the undertaking on historic properties, the agency should ensure that the State Historic Preservation Officer (SHPO) and/or the Tribal Historic Preservation Officer (THPO), Indian tribes, NHOs, and other consulting parties as appropriate have the opportunity to provide input into the identification and evaluation of historic properties. If the agency finds that either no historic properties are present or would not be affected by the response action, that determination should be memorialized in writing for inclusion in the administrative record.

(2) Assessing the effects of the undertaking on those identified historic properties.

If the agency, in consultation with the SHPO/THPO and other consulting parties, finds that “no adverse effect” would result to historic properties, that determination should be memorialized in writing for inclusion in the administrative record. While carrying out each specific step and establishing a time period for resolving disputes over effect findings are not required in this situation, the agency may ask the ACHP for advice to help resolve any disagreements with consulting parties.

Where the agency finds an adverse effect to historic properties, it would move to the next step below.

(3) The consideration of binding measures to avoid, minimize, or mitigate any potential adverse effects to historic properties.

The agency must notify the ACHP of this finding.[5] Within the context of the CERCLA process and in consultation with SHPO/THPO and other consulting parties, the agency should consider measures to avoid, minimize, or mitigate any adverse effects to historic properties, and make a commitment in a written decision document to implement those measures (e.g., in the Proposed Plan or Record of Decision).

Provided a binding written commitment is made to undertake any agreed upon measures to avoid, minimize, or mitigate adverse effects to historic properties; a separate Section 106 agreement document is not necessary to conclude the Section 106 process.

(4) Failing to reach an agreement with SHPO/THPO, and/or the ACHP on the resolution of adverse effects, request the comments of the ACHP.

In this situation, the agency should engage its Federal Preservation Officer and other relevant officials within the agency. Pursuant to Section 110(l) of the NHPA (54 U.S.C. § 306114), to evidence the agency “took into account” its effects to historic properties and provided the ACHP a “reasonable opportunity to comment,” the head of the agency must consider and respond to the ACHP’s comments in making the final agency decision. This function may not be delegated to a lower agency official.

6. Is consultation with the SHPO/THPO/Indian tribes and other parties a substantive requirement of Section 106?

The ACHP believes that consultation is a substantive requirement of Section 106 that must be met for a proposed CERCLA response action. To satisfy the statutory  “take into account” requirement, the federal agency should—as part of its CERCLA response action process—consult with certain parties, including the relevant SHPO/THPO(s), Indian tribes or NHOs, applicants, and local governments, so that its “taking into account” is actually informed by those most likely to have information and expertise relevant to the determinations regarding identification and evaluation of historic properties, assessment of effects, and establishment that the response action either would have “no adverse effect” on historic properties, or consideration of alternatives or modifications to the response action (and/or other mitigation measures) that would avoid, minimize, or mitigate adverse effects on historic properties without compromising the efficacy of the response action. A special effort should be made to consult with any Indian tribe or NHO that attaches religious and cultural significance to historic properties that may be affected by a response action. For actions occurring on or affecting historic properties located on tribal lands, the agency should consult with the relevant THPO or Indian tribe in this process. Other interested parties may be invited into the consultation process as well, including historic preservation organizations and citizen groups. When the response action may adversely affect historic properties, this consultation should also include the ACHP.

While the ACHP’s regulations specify procedural steps for how an agency can conduct consultation, including timeframes for review and processes for resolving disagreements, it is the substantive seeking, discussing, and considering the views of other participants, and, where feasible, seeking agreement that consultation seeks to accomplish. In most cases, this consultation can be most easily accommodated during the Remedial Investigation/Feasibility Study stage (or Engineering Evaluation/Cost Analysis stage for non-time-critical removal actions) of the CERCLA process.

7. Is a separate public outreach process required in coordinating Section 106 and CERCLA actions?

No. Because community involvement is built into and occurs throughout the CERCLA response action process, the federal agency is generally not required to separately engage members of the general public concerning possible effects on historic properties under Section 106. This assumes that the CERCLA response action documents that are typically made available for public review and comment will include, where appropriate, a discussion of the historic properties identified, the potential effects the response action may have on those historic properties, and how these effects have been or will be addressed during the response action process.

8. When should an agency complete the Section 106 process?

Satisfying the requirements identified above without disrupting or delaying the response action is best accomplished by addressing historic property concerns early in the CERCLA process. Section 106 compliance must be completed prior to the approval of the expenditure of any federal funds on the response action or prior to the issuance of any license necessary for the response action.

[1] See 40 CFR Part 300, 59 FR 47384 (Sept. 15, 1994).

[2] 40 CFR § 300.5. The NCP is the federal government's blueprint for responding to both oil spills and hazardous substance releases.

[3] 54 U.S.C. § 306108.

[4] See 54 U.S.C. § 302706(b) stating that under Section 106, a federal agency shall consult with any Indian tribe or NHO that attaches religious and cultural significance to a historic property that may be affected by a proposed undertaking.

[5] This step ensures the agency satisfies the statutory requirement to provide the ACHP with a reasonable opportunity to comment.

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