UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8, MONTANA OFFICE

FEDERAL BUILDING, 10 West 15TH Street, Suite 3200 Helena, MT 59626-0096

Phone 866-457-2690 www.epa.gov/region8

Ref: 8SEM-RBC ·

February 3, 2020

MEMORANDUM

SUBJECT: Compliance with the Endangered Species Ac~ fo the Butte Priority Soils Operable Unit of the Silver Bow Creek/Butte Area Superfun/ ite /

FROM: Joseph Vranka, Section Chief t~L ~ TO:

Superfund Remedial Section C v I

File/Administrative Record fort e 2020 Butte Priority Soils Operable Unit Record of Decision Amendment

This memorandum documents the Environmental Protection Agency's Endangered Species Act compliance for the 2020 Amendment to the Butte Priority Soils Operable Unit Record of Decision.

The Endangered Species Actis an applicable or relevant and appropriate requirement (ARAR) for response actions conducted at the Butte Priority Soils Operable Unit (BPSOU) pursuant to section 12l(d)(2) of the Comprehensive Environmental Response, Compensation and Liability Act as amended (CERCLA), 42 U.S.C. § 9622(f)(l)(ii)(B), and 40 CFR § 300.430(f)(l)(ii)(B). Substantive provisions of the Endangered Species Act (ESA), 16 U.S.C. §§ 1531 et seq., were identified as ARARs in the 2006 BPSOU Record of Decision.

For on-site removal and remedial actions, no permits are required. CERCLA § 12l(e) and 40 CFR § 300.400(e)(l). Under relevant CERCLA guidance issued by the EPA, this means "[o]n-site remedies must comply with substantive requirements but need not comply with the administrative and procedural requirements." See CERCLA Compliance with Other Laws Manual, Part II, p. 1-1. The Manual (at Section 4.3) discusses the ESA as an ARAR for remedial actions. The Manual also provides guidance on the meaning of substantive standards:

"Substantive compliance with the ESA means that the lead agency must identify whether a threatened or endangered species, or its critical habitat, will be affected by a proposed response action. If so, the agency must avoid the action or take appropriate mitigation measures to that the action does not affect the species or its critical habitat."

In the 2006 BPS OU Record of Decision, the EPA stated the following:

Compliance with this ARAR (the ESA) has to date involved consultation with the USFWS (the U.S. Fish and Wildlife Service), and a determination of the presence of listed or proposed species or critical habitats present at the BPSOU. The USFWS has indicated that general and informal consultation only is required for this ARAR at this operable unit, and that a full biological

assessment and biological opinion will not be necessary. See, 2006 BP SOU Record of Decision. Appendix A, page 12.

Bull trout do not exist in the surface water in and in the immediate downstream surface water bodies at the BPSOU. A fish barrier, installed by the Montana Natural Resource Damage Program at the request of the Montana Fish, Wildlife and Parks Department, approximately 20 miles downstream from the BPS OU boundary prevents the migration of bull trout and other species found in the Clark Fork River from migrating upstream into the BPSOU area. The fish barrier was installed to protect cutthroat trout in an upstream tributary of Silver Bow Creek. Because of this, and because Butte is an urban area where terrestrial species protected by the ESA do not frequent, the EPA and USFWS determined that ESA compliance was concluded for the BPSOU.

In 2018, the EPA conducted an initial Biological Assessment (BA) for the entire Silver Bow Creek/Butte Area Superfund Site (SBCBA). The SBCBA is divided into seven operable units - one of which is the BPSOU. The 2018 BA determined that the ongoing SBCBA remedial activities have no effect on the red knot and North American wolverine. The 2018 BA for the SBCBA found that the remedial activities for all of the SBCBA operable units have No Effect on critical habitat for the Canada lynx because none is designated in the action area, and May Affect, but is not likely to Adversely Affect the Canada lynx. For the grizzly bear, the 2018 BA found that the ongoing remedial actions at all of the operable units May Affect, but is Not Likely to Adversely Affect the grizzly bear, and noted that no critical habitat had been designated for the grizzly bear.

On March 14, 2018, the USFWS responded to the EPA BA by concurring on its determinations regarding these terrestrial species 1•

The 2018 SBCBA BA noted that critical habitat for the bull trout had been designated by the USFWS under the ESA for the area immediately downstream from the SBCBA site, and that bull trout are known to occur in the area immediately downstream from the SBCBA site. The downstream end of the SBCBA site is known as the Warm Springs Ponds Operable Units, and EPA's required remedial action at those operable units requires the interception and treatment of surface water from Silver Bow Creek before it is discharged into the Clark Fork River which is bull trout designated critical habitat. The 2018 BA focused its analysis on the operation of the Warm Springs Pond treatment system and its discharge. The 2018 SBCBA BA confirmed that no bull trout exist in the area above the Warm Springs Ponds, including the BPSOU, and that physical barriers preclude bull trout from accessing this area. The 2018 BA found that the ongoing SBCBA remedial activities at the Warm Springs Ponds operable unit May Affect, but is Not Likely to Adversely Affect bull trout and/or bull trout designated critical habitat.

The March 14, 2018 informal comments from the USFWS requested revisions to the 2018 SBCBA BA regarding its bull trout findings relative to the Warm Springs Ponds operable units. EPA is in the process

1 The March 14, 2018 informal and draft comments from the USFWS is considered, in part, to be deliberative and therefore protected, in part, under the Freedom of Information Act. Therefore, it is not included in the administrative record for the BPSOU Record of Decision Amendment.

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of revising the SBCBA accordingly. However, the USFWS did not disagree with the 2018 SBCBA BA findings regarding the bull trout and areas above the Warm Springs Ponds (where bull trout do not and cannot exist).

The EPA therefore concludes that the ongoing remedial actions at the BPSOU, including those authorized under the 2020 BPSOU Record of Decision Amendment, are in substantive compliance with the ESA in accordance with CERCLA and the National Contingency Plan. EPA sent an email to the USFWS on December 17, 2018, describing this finding. The USFWS has not responded to this position but has continued to work with the EPA on the revisions to the BA focusing on the Warm Springs Ponds discharge to the Clark Fork River. The December 17, 2018 email is included in the administrative record for the 2020 BPSOU Record of Decision Amendment.

The 2020 BPSOU Record of Decision Amendment provides for a limited and narrow waiver of State of Montana in-stream water quality standards during acute ( or storm) events for copper and zinc, and replaces those standards with protective federal water quality criteria for acute copper and zinc. This is done in full compliance with CERCLA, which allows for the waiver of ARARs such as in-stream water quality standards if CERCLA statutory criteria are met. See section 12l(d)(4)(C) of CERCLA, 42 U.S.C. Section 9622(d)(4)(C) and 40 CFR Section 300.430(f)(l)(ii)(C)(3). In-stream water quality in general will be substantially improved as a result of the expanded remedial activities described in the amendment. The limited waiver of standards provided for in the amendment will have no affect on the water quality entering the Warm Springs Ponds prior to treatment due to the distance between the BPSOU and the Warm Springs Ponds (over 20 miles). In addition, water entering Silver Bow Creek from tributaries to the creek downstream of the BPSOU will dilute the water quality coming from the BPSOU before it enters the Warm Springs Ponds. The difference between the Montana standards and the federal water quality criteria is minute, as explained in EPA's fact sheet regarding the waiver (the fact sheet is also part of the 2020 BPSOU Record of Decision Amendment administrative record). There are no secondary effects on the Warm Springs Ponds discharge that will result from the 2020 BPS OU Record of Decision amendment.

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