United States Court of Appeals

For the First Circuit

No. 22-1398

HOUSATONIC RIVER INITIATIVE; 

HOUSATONIC ENVIRONMENTAL ACTION LEAGUE,

Petitioners,

v.

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY, 

New England Region,

Respondent,

GENERAL ELECTRIC COMPANY; 

HOUSATONIC REST OF RIVER MUNICIPAL COMMITTEE,

Intervenors.

PETITION FOR REVIEW OF AGENCY ACTION OF

THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

Before

Gelpí, Lynch, and Montecalvo,

Circuit Judges.

Andrew Rainer, Stephanie R. Parker, and Katy T. Garrison, 

with whom Brody, Hardoon, Perkins & Kesten, LLP, O'Connor Carnathan 

& Mack LLC, and Murphy & Riley, PC were on brief, for petitioners.

Jeffrey Hammons, Trial Attorney, United States Department of 

Justice, Environment and Natural Resources Division, with whom 

Todd Kim, Assistant Attorney General, United States Department of 

Justice, Environment and Natural Resources Division, John Kilborn, 

United States Environmental Protection Agency, Region One, Timothy 

Conway, United States Environmental Protection Agency, Region One, 

and Brian Grant, United States Environmental Protection Agency, 
Office of General Counsel, were on brief, for respondent.

Kwaku A. Akowuah, with whom James R. Bieke, Madeleine Joseph, 

Sidley Austin LLP, Jeffrey R. Porter, Mintz, Levin, Cohn, Ferris, 

Glovsky & Popeo, P.C., and Andrew J. Thomas were on brief, for 

General Electric Company.

Matthew Pawa, with whom Seeger Weiss LLP was on brief, for 

Housatonic Rest of River Municipal Committee.

July 25, 2023
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LYNCH, Circuit Judge. Petitioners Housatonic River 

Initiative ("HRI") and Housatonic Environmental Action League 

("HEAL," and collectively with HRI, the "Petitioners") object to 

a permit, issued in 2020 by the Environmental Protection Agency 

(the "EPA") and affirmed in 2022 by the Environmental Appeals Board 

(the "EAB"), that requires General Electric Company ("GE") to clean 

up polychlorinated biphenyls ("PCBs") from the "Rest of River" 

reaches of the Housatonic River. The permit is supported by 

respondent-intervenors GE and the Housatonic Rest of River 

Municipal Committee (the "Municipal Committee"), an 

intergovernmental entity comprised of elected officials from the 

five towns most affected by the PCB contamination in the Rest of 

River. The permit is also supported by the State of Connecticut, 

and is not opposed by the Commonwealth of Massachusetts, which 

helped negotiate its terms. Should GE's cleanup of the Rest of 

River not achieve the goals set forth in the permit, the permit 

requires further measures. The task of this court is to evaluate 

the Petitioners' legal challenges, both procedural and 

substantive. After careful review, we deny the petition.

I. Background

A. Statutory Background

This petition for review legally involves the 

intersection of three environmental statutes: (1) the Toxic 

Substances Control Act ("TSCA"), 15 U.S.C. § 2601 et seq.; (2) the 
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Resource Conservation and Recovery Act ("RCRA"), 42 U.S.C. § 6901 

et seq.; and (3) the Comprehensive Environmental Response,

Compensation, and Liability Act ("CERCLA"), id. § 9601 et seq. We 

briefly summarize the relevant provisions of each statute.

Congress passed TSCA in 1976 with the purpose of 

"regulat[ing] chemical substances and mixtures which present an 

unreasonable risk of injury to health or the environment." 15 

U.S.C. § 2601(b)(2). Among other provisions, TSCA requires the 

EPA to regulate the use and disposal of PCBs. See id. § 2605(e)(1); 

Town of Westport v. Monsanto Co., 877 F.3d 58, 63 (1st Cir. 2017). 

Under those regulations, any person disposing of "PCB remediation 

waste" "shall do so based on the concentration at which the PCBs 

are found" in that waste. 40 C.F.R. § 761.61. In particular, 

materials with PCB concentrations of under 50 parts per million 

("ppm") can be disposed of in a facility licensed to manage 

municipal solid waste or non-municipal non-hazardous waste. See

id. § 761.61(a)(5)(i)(B)(2)(ii), .61(a)(5)(v)(A)(1)-(2). By 

contrast, materials with PCB concentrations equal to or exceeding 

50 ppm must be disposed of in a more protective facility dedicated 

to hazardous waste or PCBs. See id. §§ 761.61(a)(5)(i)(B)(2)(iii),

.75; 42 U.S.C. §§ 6924, 6926.

Congress enacted RCRA, also in 1976, with the goal of 

closing "the last remaining loophole in environmental law, that of 

unregulated land disposal of discarded materials and hazardous 
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waste." Me. People's All. & Nat. Res. Def.

Council v. Mallinckrodt, Inc., 471 F.3d 277, 287 (1st Cir. 2006) 

(quoting H.R. Rep. No. 94-1491, pt. 1, at 4 (1976)). RCRA 

generally requires any owner or operator of a facility that 

"treat[s], stor[es], or dispos[es] of hazardous waste" to acquire 

a permit. 42 U.S.C. § 6925(a); see W.R. Grace & Co.--Conn. v. 

U.S. EPA, 959 F.2d 360, 361 (1st Cir. 1992). That permit must 

require "corrective action for all releases of hazardous waste"

from the facility, 42 U.S.C. § 6924(u), and may also include any 

"terms and conditions as the [permit issuer] determines necessary 

to protect human health and the environment," id. § 6925(c)(3). 

Following any administrative appeals to the EAB, see 40 C.F.R. 

§ 124.19(a)(l), "any interested person" may seek immediate review 

of a RCRA permit in the federal court of appeals, 42 U.S.C. 

§ 6976(b).

Finally, CERCLA, enacted in 1980, empowers the EPA to 

require remedial action when there is a "release or substantial 

threat of release" of "any hazardous substance" or of "any 

pollutant or contaminant which may present an imminent and 

substantial danger to the public health or welfare." 42 U.S.C. 

§ 9604(a)(1); see Emhart Indus., Inc. v. U.S. Dep't of the Air 

Force, 988 F.3d 511, 516 & n.3 (1st Cir. 2021). Under CERCLA, the 

EPA can order "responsible parties" to carry out the chosen 

response action. Emhart, 988 F.3d at 517 (quoting Key Tronic 
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Corp. v. United States, 511 U.S. 809, 813-14 (1994)); see 42 U.S.C. 

§ 9607(a). That remedial action must achieve an adequate degree 

of cleanup, see 42 U.S.C. § 9621(d)(1), and typically must conform 

to "applicable or relevant and appropriate" state and federal 

standards, id. § 9621(d)(2)(A), known as "ARARs." Unlike a RCRA 

permit, a CERCLA remedial action order often cannot be challenged

by a responsible party until the EPA has taken action to enforce 

the order. See id. § 9613(h). Regulations governing CERCLA 

remedial actions are set forth in the National Oil and Hazardous 

Substances Pollution Contingency Plan (the "National Contingency 

Plan"). See 40 C.F.R. § 300.1 et seq.

B. Factual Background

1. The PCB Contamination

The Housatonic River originates in two separate branches 

several miles north of the City of Pittsfield, Massachusetts. 

Below the confluence of those two branches, the Housatonic extends 

south for over 125 miles through western Massachusetts and 

Connecticut, ultimately emptying into Long Island Sound. The 

portion of the river downstream from the confluence is known, for 

purposes of this litigation, as the "Rest of River." The Rest of 

River comprises twelve segments or "reaches," designated as 

Reaches 5 through 16. This petition concerns the Rest of River.

For much of the twentieth century, GE operated an 

electrical transformer manufacturing facility along one of the 
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branches north of the confluence. The decades-long operation of 

this facility resulted in extensive contamination of the river 

with PCBs. The worst of the contamination occurred north of the 

confluence, but the PCBs also migrated throughout the Rest of 

River.

2. The Consent Decree

In the 1970s, the EPA and Massachusetts began 

investigating and implementing remedial actions to address the PCB 

contamination in the Housatonic. That process culminated in 2000, 

when GE entered into a Consent Decree with the United States, 

Massachusetts, Connecticut, the City of Pittsfield, and the 

Pittsfield Economic Development Authority.1 The Consent Decree, 

which was approved by the U.S. District Court for the District of 

Massachusetts in October 2000, was intended "to resolve the 

[parties'] claims for response actions, response costs and natural 

resource damages in connection with" the PCB contamination from 

GE's manufacturing facility. In particular, under the Consent 

Decree, GE agreed to conduct remediation of the river, and the 

various government signatories agreed to resolve GE's liability 

under RCRA, CERCLA, and other applicable law.

1 The Consent Decree included, as an attachment, a draft 

RCRA permit that was to be revised upon the selection of a remedy 

for the Rest of River. We refer to the Consent Decree and the 

attached permit collectively as the "Consent Decree."
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The Consent Decree laid out a cleanup plan for two 

different portions of the Housatonic. First, GE was required to 

remediate the contamination at the facility itself and at nearby 

areas north of the confluence. That cleanup is not at issue in 

this case.

Second, the Consent Decree created a process for 

selecting a remedy for the Rest of River (i.e., Reaches 5 through 

16). Under the Consent Decree, that remedy -- which is the subject 

of the present litigation -- would be embodied in a RCRA corrective 

action permit, but would also "be considered to be the final remedy 

selection decision pursuant to Section 121 of CERCLA and Section 

300.430 of the [National Contingency Plan]." See 42 U.S.C. § 9621;

40 C.F.R. § 300.430. This unusual remedial structure afforded GE 

and other interested persons the immediate rights of review

associated with a RCRA permit, see 42 U.S.C. § 6976(b), while 

subjecting the selected response action to the cleanup 

requirements of CERCLA and the National Contingency Plan. One 

such CERCLA provision requires conforming to federal and state 

ARARs,2 see id. § 9621(d)(2)(A), including TSCA's PCB disposal 

restrictions, see 15 U.S.C. § 2605(e)(1); 40 C.F.R. §§ 761.61, 

.75. Consistent with RCRA regulations, see 40 C.F.R. 

2 The Consent Decree also expressly required the EPA to 

identify ARARs and, if the EPA decided to waive any such ARARs, 

see 42 U.S.C. § 9621(d)(4), to explain the basis for any such 

waiver.
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§ 124.10(a)(1)(ii), the Consent Decree further required that the 

proposed permit be subject to public comment.

The Consent Decree laid out a phased process for 

selecting the Rest of River remedy, including the performance of 

new and various studies and investigations by both GE and the EPA. 

Of particular importance to this petition for review, the Consent 

Decree required the consideration of, "[a]t a minimum," nine 

criteria (the "Selection Criteria") in selecting the remedy. The 

Selection Criteria are as follows: (1) "Overall Protection of Human 

Health and the Environment"; (2) "Control of Sources of Releases"; 

(3) "Compliance with [ARARs]"; (4) "Long-Term Reliability and 

Effectiveness"; (5) "Attainment of Interim Media Protection 

Goals"; (6) "Reduction of Toxicity, Mobility, or Volume of Wastes"; 

(7) "Short-Term Effectiveness"; (8) "Implementability"; and 

(9) "Cost." The Consent Decree envisioned a remedy that would be 

"best suited to meet the [first three criteria] . . . in 

consideration of the [latter six criteria] . . . including a 

balancing of [the latter six criteria] against one another."3

3. The 2016 Permit Issued After Notice and Comment

In June 2014, after over a decade of further research by 

GE and the EPA, the EPA issued a draft RCRA permit embodying a 

3 The nine Selection Criteria closely resemble analogous 

factors promulgated in the National Contingency Plan that are used 

to select a response action under CERCLA. See 40 C.F.R. 

§ 300.430(e)(9)(iii), (f)(1)(i).
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proposed remedy for the Rest of River. In conjunction with the 

draft permit, the EPA published a written analysis (the "2014 

Comparative Analysis") comparing various cleanup alternatives 

under the nine Selection Criteria and explaining the EPA's basis 

for its proposed choice. Following a public comment period and 

formal dispute resolution invoked by GE, the EPA issued a final 

permit in October 2016 (the "2016 Permit").

In designing the 2016 Permit, the EPA faced three major 

issues that are central to this case: (1) how to remediate the PCB 

contamination in the Rest of River, including whether and how to 

remove PCB-contaminated material from that area; (2) whether and 

how to apply treatment technologies to that removed material in 

order to reduce its toxicity and the risk of PCB dispersal; and 

(3) where and how to dispose of the removed material. The EPA 

resolved those issues as follows in the 2016 Permit.

First, as to remediation, the 2016 Permit required GE to 

excavate and remove almost one million cubic yards of PCBcontaminated sediment and soil from the Rest of River, its 

floodplain, and certain surrounding areas. GE would then install 

engineered caps in many of those areas in order to "physically and 

chemically isolate the residual PCBs in [the remaining] 

sediment[,] . . . provide habitat for aquatic plants and animals[,] 
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and reduce downstream transport of PCBs."4 These removal and 

capping activities -- which generally would aim to reduce the 

average PCB concentrations in remaining sediment to 1.00 ppm in 

most areas -- would occur primarily in the upstream areas of the 

Rest of River, where PCBs are more prevalent; in particular, these 

activities were required in Reaches 5, 6, and 8, and in the 

impoundments of Reach 7. For the areas further downstream, the 

2016 Permit did not require any removal of sediment or soil;

rather, it mandated "monitored natural recovery" ("MNR").5 MNR 

relies on natural processes -- rather than active remediation 

measures like removal and capping -- to reduce PCB contamination 

over time.6

Second, as to treatment of the excavated and removed 

material, the EPA considered various forms of treatment 

technologies and studied two of them in depth. One of those two 

4 The 2016 Permit further required the placement of 

backfill material in certain areas following sediment and soil 

removal.

5 MNR was the selected remedy for the flowing subreaches 

of Reach 7 and for Reaches 9 through 16.

6 To be precise, the 2016 Permit defined MNR as "a remedy 

for contaminated sediment that typically uses ongoing, naturally 

occurring processes to contain, destroy, or reduce the 

bioavailability or toxicity of contaminants in sediment, and 

requires monitoring the natural processes and/or concentrations of 

contaminants in surface water, sediment, or biota to see if 

recovery is occurring at the expected rate, and the maintenance of 

institutional controls until the necessary reductions in risk have 

occurred."
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treatment technologies was thermal desorption, which "removes 

contaminants [from sediment and soil] by raising the temperature 

of the contaminated material to transfer the contaminants from the 

sediment or soil to a gas stream," which is then separately treated 

and disposed of.7 The EPA ultimately decided not to require any 

treatment of the removed sediment and soil. The 2016 Permit did, 

however, require GE to use "activated carbon or [an]other sediment 

amendment"8 in certain areas of the Rest of River to reduce the 

toxicity of sediment and soil that would not be removed.

Finally, as to disposal, the EPA considered whether to 

require fully offsite disposal or fully onsite disposal of the 

removed material. The EPA did not consider or evaluate any other 

proposal for disposing of untreated material other than fully 

offsite or fully onsite disposal. Fully offsite disposal "would 

involve the transportation of removed sediment and floodplain soil 

to commercial solid waste and/or TSCA-licensed landfill(s) for 

disposal." Fully onsite disposal, on the other hand, "would 

7 The other treatment technology considered in depth by 

the EPA was "chemical extraction," which is the "process of mixing 

an extraction fluid/solvent with removed sediment and soil, so 

that PCBs in the sediment or soil are . . . transferred into the 

extraction fluid."

8 Treatment with activated carbon involves "increasing the 

sediment['s] organic carbon content" in order to "decrease[] 

contaminant bioavailability," which in turn "allow[s] higher 

concentrations of contaminants to remain" in the sediment "without 

adverse biological effects."
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involve the permanent disposition of the removed sediment/soil at 

an [onsite] [f]acility constructed in close proximity to the 

[r]iver, but outside the 500-year floodplain."9 Comparing these 

two alternatives through the lens of the nine Selection Criteria, 

the EPA found that both options "would provide protection of human 

health and the environment," but ultimately concluded that fully 

offsite disposal was preferable. As between the two, the EPA found 

that fully offsite disposal would best prevent releases of PCBs, 

would be more reliable and effective than fully onsite disposal in 

the long term, and would have various other benefits. Accordingly, 

the 2016 Permit required GE to transport all removed material to 

existing licensed offsite facilities.

4. The 2018 EAB Decision

In November 2016, five parties petitioned the EAB for 

review of the 2016 Permit. Two of those parties -- GE and a local 

landowner named C. Jeffrey Cook -- argued that the remedy under 

the 2016 Permit was too extensive. The other three parties --

HRI, the Berkshire Environmental Action Team, and the Municipal 

Committee -- contended that the cleanup was not extensive enough. 

The Municipal Committee was formed under an intergovernmental 

agreement by five towns in Berkshire County, Massachusetts: Great 

9 The EPA also considered onsite disposal in a "confined 

disposal facility . . . in a local waterbody," but it ultimately 

rejected that alternative, and that alternative is not relevant to 

this case.
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Barrington, Lee, Lenox, Sheffield, and Stockbridge. Those five 

towns, as well as the City of Pittsfield, are apparently the 

municipalities most affected by the Rest of River cleanup.

Several other entities -- including Massachusetts, 

Connecticut, the City of Pittsfield, and the Massachusetts Audubon 

Society -- participated in the proceedings before the EAB by filing 

either amicus briefs or responses to petitions.

In January 2018, the EAB, finding legal error in part of 

EPA's selection of the disposal remedy, issued a 152-page opinion 

remanding the 2016 Permit in part and denying review in part. In 

re Gen. Elec. Co. (Gen. Elec. I), 17 E.A.D. 434 (EAB 2018). The 

opinion addressed challenges, raised variously by the five 

petitioners, to all three major aspects of the 2016 Permit: 

remediation, treatment, and disposal.

As to the remediation of the Rest of River and the 

removal of the PCB-contaminated material from that area, the EAB 

upheld almost all provisions of the 2016 Permit, see id. at 487-

519, 523-58, remanding the permit on only one ground that is not 

relevant here, see id. at 520-23. Of particular relevance to this 

case, the EAB rejected HRI's challenge to the provisions of the 

2016 Permit that selected MNR as the remedy for most of the 

downstream reaches of the Rest of River. See id. at 536-40. The 

EAB found that HRI had failed to adequately explain why the EPA's 
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selection of MNR for those downstream reaches was clearly 

erroneous. See id.

The EAB also rejected HRI's argument that the 2016 Permit 

should have required treatment of the excavated and removed 

material from the upstream reaches. See id. at 577-83. First, 

addressing HRI's assertion that the EPA should have mandated 

thermal desorption, the EAB found that HRI had failed to 

demonstrate that that issue was raised during the public comment 

period. See id. at 577-81. Next, the EAB rejected HRI's argument 

that the 2016 Permit should have required "bioremediation," see

id. at 581-82, a treatment technology that "would involve 

introducing microorganisms and/or nutrients into the [sediment and

soil] to increase ongoing biodegradation rates of PCBs." Finally, 

the EAB rejected HRI's contention that the 2016 Permit failed to 

comply with CERCLA's preference for treatment, see 42 U.S.C. 

§ 9621(b)(1) (generally requiring the EPA to "select a remedial 

action . . . that utilizes permanent solutions and alternative 

treatment technologies or resource recovery technologies to the 

maximum extent practicable"), finding that no individual had 

raised the issue during the public comment period and that the 

argument would fail on substantive grounds in any event, see Gen. 

Elec. I, 17 E.A.D. at 582-83, 583 n.63.

Highly pertinent to this case, the EAB also addressed 

GE's argument that the EPA erred in selecting fully offsite 
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disposal. See Gen. Elec. I, 17 E.A.D. at 559-69. On this issue, 

the EAB remanded the 2016 Permit, finding that the EPA had failed 

to exercise considered judgment. See id. at 565-69. The EAB noted 

that the EPA had premised its selection of fully offsite disposal 

largely on the conclusion that a fully onsite disposal facility 

would be unable to satisfy TSCA regulations governing the disposal 

of materials containing PCBs in concentrations of 50 ppm or 

greater. See id. at 559, 561-65; 40 C.F.R. § 761.75. The EAB 

held, to the contrary, that the EPA had failed to address GE's 

arguments that an onsite facility could satisfy those regulations 

and could qualify for a waiver of certain TSCA requirements. See

Gen. Elec. I, 17 E.A.D. at 565-69.

The EAB thus denied HRI's petition in full, including 

its challenges to the 2016 Permit's provisions regarding MNR and 

treatment.10 See id. at 584. In response to GE's petition, the 

EAB remanded the 2016 Permit for the EPA to reconsider the 

"provisions of the [2016] Permit pertaining to" disposal. Id. at 

584-85.

5. The Settlement

Following the EAB's remand of the permit, the EPA invited 

various stakeholders to participate in confidential mediated 

10 The EAB also denied the petitions of C. Jeffrey Cook, 

the Municipal Committee, and the Berkshire Environmental Action 

Team. See Gen. Elec. I, 17 E.A.D. at 584.
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discussions to attempt to agree upon a revised remedy. The EPA 

invited all five petitioners from the prior EAB proceedings –- GE, 

HRI, the Municipal Committee, the Berkshire Environmental Action 

Team, and C. Jeffrey Cook -- as well as HEAL, the State of 

Connecticut, the Commonwealth of Massachusetts, the City of 

Pittsfield, and the Massachusetts Audubon Society. Of these 

parties, all proceeded to participate in mediation except for the 

Petitioners. HRI attended the discussions initially, but then 

"declined to participate in any discussions or agreement that 

involved onsite disposal and from which the general public was 

excluded." HEAL, similarly, was unwilling to participate in 

confidential discussions.11

The mediation ultimately concluded in February 2020 with 

the signing of a settlement agreement (the "Settlement"). The 

Settlement was signed by almost all of the participants in the 

mediation: the EPA, GE, the Municipal Committee, the Berkshire 

Environmental Action Team, C. Jeffrey Cook, the State of 

Connecticut, the City of Pittsfield, and the Massachusetts Audubon 

Society. The Municipal Committee joined the Settlement through 

the signatures of the chairpersons of each of the five member 

11 The parties to this case disagree on whether HEAL was 

"excluded" from the discussions or, like HRI, voluntarily declined 

to participate. But the Petitioners concede that to the extent 

HEAL was "excluded," that exclusion was due to its unwillingness 

to maintain the confidentiality of the mediation.
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towns' select boards. The Commonwealth of Massachusetts did not 

sign the Settlement but also did not oppose it. Neither HRI nor 

HEAL signed the Settlement.

The Settlement required the EPA to propose a revised 

permit, which would be "subject to a regulatory public comment 

process" and which the signatories "agree[d] not to 

challenge . . . unless it [was] inconsistent with the terms of 

th[e] Settlement." The revised permit would include revised 

provisions regarding both the remediation of the Rest of River and 

the disposal of removed PCB-contaminated material.

As to remediation, the revised proposal would require GE 

to excavate and remove an increased amount of contaminated sediment 

and soil from the Rest of River, including from areas not required 

under the 2016 Permit. In certain areas of the Rest of River, the 

increased sediment removal would reduce PCB contamination to a 

sufficiently low level that capping would no longer be necessary. 

The revised proposal would also impose new and additional 

requirements on GE to remediate more than twenty additional 

residential properties; remove two dams; conduct a pilot study on 

a revised remedial approach for vernal pools; and develop a 

quality-of-life plan addressing various community impacts such as 

noise, air pollution, odor, road use, and public safety. Most 

other remedial measures from the 2016 Permit -- including MNR for 

the downstream reaches -- would remain unchanged.
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Crucially for purposes of this case, as to the disposal

of excavated and removed material, the Settlement envisioned a new 

approach called "hybrid disposal," which utilized both offsite and 

onsite disposal based on the degree of contamination of the soil 

and sediment removed from the Rest of River. Under the hybrid 

disposal approach, floodplain and bank soil with average PCB 

concentrations equal to or exceeding 50 ppm, and sediment with 

average PCB concentrations exceeding 25 ppm, would be transported 

for disposal in a licensed offsite facility. Floodplain and bank 

soil with average PCB concentrations below 50 ppm, and sediment 

with average PCB concentrations of 25 ppm or lower, would be 

disposed of in an onsite facility with the significant protections 

of a cap, double liner, leachate collection system, groundwater 

monitoring network, and stormwater management system. The 

Settlement further provided that GE would be required to dispose 

of at least 100,000 cubic yards of contaminated material offsite.

In addition to the provisions regarding the revised 

permit proposal, the Settlement included several other covenants 

between the signatories. For example, GE "agreed to commence and 

perform investigation and design work" on the Settlement's 

effective date, with that obligation to "continue unless and until"

the EPA issued a revised permit with terms that were not 

"substantially similar" to the agreed-upon proposal. GE also 

agreed to make payments and donate land to the City of Pittsfield, 
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the Massachusetts Audubon Society, and the five towns represented 

by the Municipal Committee, and agreed to make aesthetic 

improvements to various other properties. The EPA agreed to 

"facilitate opportunities for research and testing of innovative 

treatment" for "reducing PCB toxicity and/or concentrations" in 

excavated and removed material.

6. The 2020 Permit Issued After Notice and Comment

In July 2020, the EPA issued a draft revised permit which 

incorporated the terms of the Settlement. In conjunction with the 

draft revised permit, the EPA published a written analysis (the 

"2020 Comparative Analysis") comparing the draft revised permit 

with the 2016 Permit under the nine Selection Criteria.

The 2020 Comparative Analysis concluded that the 

remedial portions of the draft revised permit outperformed those 

of the 2016 Permit because the revised draft would include 

significant new benefits, including increased removal of 

contaminated material, reduced need for capping, and enhanced

habitat restoration. As to disposal, the 2020 Comparative Analysis 

found that hybrid disposal better satisfied the nine Selection 

Criteria than the fully offsite disposal approach embodied in the 

2016 Permit. Acknowledging that fully offsite disposal 

outperformed hybrid disposal with respect to some criteria, the 

EPA found that hybrid disposal had various benefits, including 

significantly reduced greenhouse gas emissions from transporting 
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lesser quantities of contaminated material to an offsite facility 

(or multiple offsite facilities if one did not meet the needed 

capacity), decreased number of truck trips and associated injuries 

and fatalities, approval and cooperation from the affected 

municipalities, and lower cost. With regard to "Overall Protection 

of Human Health and the Environment" (i.e., the first of the 

Selection Criteria), the 2020 Comparative Analysis also noted that 

the hybrid disposal approach was "part of a Settlement . . . that 

includes numerous enhancements to the floodplain and sediment 

remedies, an expedited start to implementation, and community 

coordination and benefits." Comparing the draft revised permit to 

the 2016 Permit in their totalities, the EPA concluded that the 

"combination" of the updated remedial provisions and hybrid 

disposal approach in the revised draft permit was "best suited" to 

satisfy the Selection Criteria and "satisfactorily addresse[d] the 

issues raised by the EAB" in its 2018 decision.

The EPA received public comments on the draft revised 

permit from July to September 2020. Those comments concerned 

various aspects of the revised draft, including its provisions 

concerning MNR, treatment, and hybrid disposal. Several 

commenters also raised questions about the mediations that had 

produced the Settlement. In December 2020, the EPA issued a 

lengthy document responding to the various comments. Although the 

EPA declined to adopt most of the commenters' suggestions, it did 
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agree to make several minor changes to the permit and summarized 

those changes in an attachment to the document.

Having considered the comments and the record, the EPA 

issued a final permit in December 2020 (the "2020 Permit"), 

incorporating all major terms of the Settlement. The 2020 Permit 

requires GE to remove over 1.1 million cubic yards of contaminated 

material from the Rest of River, its floodplain, and certain 

surrounding areas -- an increase of more than 14 percent from the 

2016 Permit. The 2020 Permit also decreases reliance on capping.12 

Like the 2016 Permit, the 2020 Permit requires MNR -- rather than 

excavation and removal -- for downstream reaches of the Rest of 

River. Also like the 2016 Permit, the 2020 Permit does not require 

any treatment of removed material prior to disposal, but does 

require the application of activated carbon or another sediment 

amendment in certain areas of the Rest of River.

With respect to disposal, the 2020 Permit incorporates 

the hybrid disposal approach articulated in the Settlement, such

that excavated materials with higher levels of PCB contamination 

will be transported offsite, while less-contaminated materials 

will be sent to an onsite facility. The 2020 Permit concludes 

12 Like the 2016 Permit, the 2020 Permit also requires the 

placement of backfill material in certain areas. The 2020 Permit 

reduces the amount of capping, backfill, and stabilization 

material by more than 150,000 cubic yards compared to the 2016 

Permit.
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that the onsite facility will "not pose an unreasonable risk of 

injury to health or the environment," thus entitling GE to a waiver 

of TSCA's requirements for the disposal of PCB remediation waste 

with PCB concentrations under 50 ppm. 40 C.F.R. § 761.61(c)(2). 

The facility will be located in a former gravel mining pit near 

Woods Pond, a small portion of a much greater area that has been 

designated by Massachusetts regulation as an "Area of Critical 

Environmental Concern" (an "ACEC"). See 310 Mass. Code Regs.

§ 16.40(4)(d). This Massachusetts regulation would, unless waived 

by the EPA, prevent the siting of a solid waste management facility 

within an ACEC, see id. § 16.40(4)(d)(1), but the 2020 Permit finds 

that even if the regulation is an ARAR, it can be waived under 

CERCLA because "compliance [with the regulation] . . . will result 

in greater risk to human health and the environment than 

alternative options," 42 U.S.C. § 9621(d)(4)(B).

7. The 2022 EAB Decision

In early 2021, the Petitioners petitioned the EAB for 

review of the 2020 Permit. The Petitioners challenged two aspects 

of the 2020 Permit that were unchanged from the 2016 Permit and 

that had been upheld by the EAB in 2018: first, the EPA's selection 

of MNR (rather than excavation and removal) for downstream reaches 

of the Rest of River, and second, the EPA's decision not to require 

treatment of excavated material prior to disposal. The Petitioners 

further challenged the 2020 Permit's hybrid disposal provisions, 
- 24 -

arguing that the EPA had reversed course and that that alleged 

reversal of course was unlawfully based on the Settlement rather 

than on a reasoned comparison of the disposal options.

In February 2022, the EAB issued a 103-page opinion 

upholding the 2020 Permit in full. In re Gen. Elec. Co. (Gen. 

Elec. II), 18 E.A.D. 575 (EAB 2022). The EAB rejected the 

Petitioners' various challenges to the EPA's overall conclusions 

as to MNR, treatment, and hybrid disposal.

As to MNR and treatment, the EAB held that the 

Petitioners' arguments were not within the EAB's scope of review, 

because the EAB had already upheld the MNR and treatment provisions 

in the 2016 Permit and those provisions had remained unchanged in 

the 2020 Permit. See id. at 663-77. The EAB further concluded 

that even if it were to consider the Petitioners' new arguments as 

to MNR, those arguments would fail on the merits.13 See id. at 

674-77.

As to hybrid disposal, the EAB rejected the Petitioners' 

claims that the EPA had reversed its position from the 2016 Permit, 

finding instead that the EPA had analyzed a new disposal option 

with different environmental implications. See id. at 619-63. 

13 Although the EAB did not, in its 2022 decision, discuss 

the merits of the Petitioners' arguments concerning treatment, 

those arguments were substantively the same as the ones the 

Petitioners had unsuccessfully advanced when challenging the 2016 

Permit.
- 25 -

The EAB further upheld the EPA's decision to waive Massachusetts'

ACEC regulation under CERCLA, see id. at 635-48, and rejected the 

Petitioners' contention that the Settlement had improperly 

influenced the EPA's remedy-selection process, see id. at 652-61.

Having been upheld by the EAB, the 2020 Permit became 

effective in March 2022. We turn to the Petitioners' challenges, 

both procedural and substantive, to the 2020 Permit.

II. Constitutional Standing

The EPA's issuance of a RCRA permit may be challenged by 

"any interested person." 42 U.S.C. § 6976(b). The EPA does not 

dispute that the Petitioners are "interested person[s]" having a 

right to appeal the 2020 Permit. The EPA does contend, however, 

that the Petitioners lack constitutional standing to challenge the 

2020 Permit. This argument fails.

Because the Petitioners are associations, they must 

demonstrate their "standing to bring suit on behalf of [their] 

members" by showing that (1) "[their] members would otherwise have 

standing to sue in their own right"; (2) "the interests [they] 

seek[] to protect are germane to the organization[s'] purpose[s]"; 

and (3) "neither the claim asserted nor the relief requested 

requires the participation of individual members in the lawsuit." 

Hunt v. Wash. State Apple Advert. Comm'n, 432 U.S. 333, 343 (1977).

The first two prongs of this test have constitutional dimensions; 

the third prong is prudential. See United Food & Com. Workers 
- 26 -

Union Loc. 751 v. Brown Grp., Inc., 517 U.S. 544, 554-58 (1996); 

see also Back Beach Neighbors Comm. v. Town of Rockport, 63 F.4th

126, 129 n.2 (1st Cir. 2023). The Petitioners have each satisfied 

all three requirements.

First, each association has adequately shown that "at 

least one of its members would have standing to sue as an 

individual." Animal Welfare Inst. v. Martin, 623 F.3d 19, 25 (1st 

Cir. 2010); see Draper v. Healey, 827 F.3d 1, 3 (1st Cir. 2016) 

(noting that "the association must, at the very least, 'identify 

[a] member[] who ha[s] suffered the requisite harm.'" (alterations 

in original) (quoting Summers v. Earth Island Inst., 555 U.S. 488, 

499 (2009))). Both HRI and HEAL identified at least one member 

who "suffered an injury in fact that [was] concrete, 

particularized, and actual or imminent," "likely caused by the 

defendant," and "likely [to] be redressed by judicial relief." 

Plazzi v. FedEx Ground Package Sys., Inc., 52 F.4th 1, 4 (1st Cir. 

2022) (quoting TransUnion LLC v. Ramirez, 141 S. Ct. 2190, 2203 

(2021)). For example, affidavits submitted by the Petitioners

identify members who live near the proposed onsite disposal site, 

use that area for recreation and/or commerce, and fear that the 

disposal facility will negatively impact their use and enjoyment 

of the area and their property values. Those imminent injuries 

plainly constitute injuries in fact, see Friends of the Earth, 

Inc. v. Laidlaw Env't Servs. (TOC), Inc., 528 U.S. 167, 183 (2000) 
- 27 -

("[E]nvironmental plaintiffs adequately allege injury in fact when 

they aver that they use the affected area and are persons 'for 

whom the aesthetic and recreational values of the area will be 

lessened' by the challenged activity." (quoting Sierra Club v. 

Morton, 405 U.S. 727, 735 (1972))); Kathrein v. City of Evanston, 

636 F.3d 906, 914 (7th Cir. 2011) ("A demonstrable reduction in 

the market value of one's property is an injury in fact for 

standing purposes."), are caused by the EPA's approval of the 

onsite disposal facility, and would be redressed by the requested 

reversal of that approval.

Second, the "interests at stake are germane to the

[Petitioners'] purpose[s]." Animal Welfare Inst., 623 F.3d at 25 

(quoting Friends of the Earth, 528 U.S. at 181). HRI was "formed 

with the specific mission of cleaning the Housatonic River and 

surrounding sites of PCB[s] and other chemical contamination." 

HEAL, in turn, is "dedicated to the protection of the Housatonic 

River and its watershed" and "ultimate[ly] [aims for] a swimmable 

and fishable river in both Massachusetts and Connecticut." The 

"interests at stake" in this litigation are clearly "related to

the [Petitioners'] core purposes." Mallinckrodt, 471 F.3d at 283.

Finally, "individual members' participation is not 

necessary to either the claim asserted or the relief requested." 

Animal Welfare Ins., 623 F.3d at 25. The Petitioners ask us to 

vacate the EPA's approval of the 2020 Permit and to order the EPA 
- 28 -

to consider changing several permit provisions on remand. That 

requested "prospective relief" would "inure to the benefit of those 

members of the [Petitioners] actually injured," supporting a 

finding of associational standing. Warth v. Seldin, 422 U.S. 490, 

515 (1975); see Playboy Enters., Inc. v. Pub. Serv. Comm'n of P.R., 

906 F.2d 25, 35-36 (1st Cir. 1990).

The Petitioners thus have satisfied all three 

requirements of associational standing.14 We now turn to the merits 

of the Petitioners' procedural and substantive challenges.

III. Procedural Challenge Regarding the Mediation Process

We first address the Petitioners' procedural challenge 

to the 2020 Permit. See 5 U.S.C. § 706(2)(D) (requiring a 

reviewing court to set aside any agency action made "without 

observance of procedure required by law"). The Petitioners do not 

dispute that the EPA satisfied RCRA's requirements concerning 

public notice and comment, see 40 C.F.R. § 124.10; rather, they 

contend that the mediation process, which took place from 2018 to 

2020 and ultimately produced the Settlement, improperly influenced 

14 The EPA argues that because the "Petitioners' brief 

contains no discussion of their standing . . . [the] Petitioners 

have not met their burden to establish standing." But no such 

requirement of explicitly proclaiming to have standing exists. 

See Fed. R. App. P. 28 (listing requirements for appellate briefs, 

but not requiring any express statement of standing). Rather, 

parties seeking to avail themselves of the federal courts simply 

must plead "facts demonstrating standing," Animal Welfare Inst., 

623 F.3d at 25, and the Petitioners have done so.
- 29 -

the remedy selection process and rendered the notice-and-comment 

process a "façade." They argue that the EPA was required to allow 

public access to the mediation and maintain an administrative

record of the negotiations, and that its failure to do so violated 

the Consent Decree, CERCLA, and the Administrative Procedure 

Act ("APA"), 5 U.S.C. § 551 et seq.

We first reject out of hand the Petitioners' argument 

that the Consent Decree requires notice and comment prior to 

mediation and provides that mediation must occur on the record. 

This argument misconstrues the Consent Decree, which in fact 

requires only that the draft permit for the Rest of River cleanup 

be subject to RCRA regulations, "including the provisions 

requiring public notice and an opportunity for public comment,"

and provides that after the public comment period, GE may invoke 

an "administrative dispute resolution" process that must be on the 

record. Outside of that formal dispute resolution process, which 

is not at issue here, the Consent Decree contains no requirement 

of public input prior to mediation or of maintaining an 

administrative record of negotiations. On the contrary, the 

Consent Decree provides that any "participants in mediated 

discussions . . . shall execute a confidentiality agreement."

The Petitioners' invocations of CERCLA are similarly 

unavailing. The Petitioners correctly note that CERCLA requires 

the EPA to "[p]rovide a reasonable opportunity" for public comment 
- 30 -

"[b]efore adoption of any plan for remedial action." 42 U.S.C. 

§ 9617(a)(2). But the notice-and-comment period here did take 

place before the issuance of the 2020 Permit, and the Petitioners 

identify no provision in CERCLA prohibiting the EPA from engaging 

in mediation to investigate potential remedies. In fact, "early 

settlement[]" of the liability of potentially responsible parties 

"is an integral part of the statutory plan" under CERCLA. Emhart, 

988 F.3d at 517 (alteration in original) (quoting United States v. 

Cannons Eng'g Corp., 899 F.2d 79, 92 (1st Cir. 1990)).

Beyond these narrow arguments concerning the Consent 

Decree and CERCLA, the Petitioners contend more broadly that an 

agency should not be permitted to use mediation to help determine 

what provisions to include in a draft permit, particularly when 

that mediation is off the record and closed to the public. This 

argument fails to account for the Supreme Court's consistent 

statements that "[b]eyond the APA's minimum requirements, courts 

lack authority 'to impose upon [an] agency [their] own notion of 

which procedures are "best" or most likely to further some vague, 

undefined public good.'" Perez v. Mortg. Bankers Ass'n, 575 U.S. 

92, 102 (2015) (second alteration in original) (quoting Vt. Yankee 

Nuclear Power Corp. v. Nat. Res. Def. Council, Inc., 435 U.S. 519, 

549 (1978)); see Vt. Yankee, 435 U.S. at 524 ("Agencies are free 

to grant additional procedural rights in the exercise of their 

discretion, but reviewing courts are generally not free to impose 
- 31 -

them if the agencies have not chosen to grant them."). And nothing 

in the APA prohibits mediation prior to issuing a draft permit, 

requires any such mediation to be on the record, or provides for 

public access to such mediation. See, e.g., N.Y. State Dep't of 

L. v. FCC, 984 F.2d 1209, 1218-19 (D.C. Cir. 1993) (rejecting 

petitioner's argument that the APA "single[s] out settlement 

discussions and related proposals as requiring public disclosure 

and opportunity for comment and/or involvement" and noting that 

even in the context of formal adjudications, "informal settlement"

is "authorized . . . before undertaking the more formal hearing 

procedure" (alteration in original) (quoting S. Doc. No. 248, at 

24 (1945))).15 We thus conclude that no procedural violation has 

occurred. Cf. City of Taunton v. EPA, 895 F.3d 120, 132 (1st Cir. 

2018) (rejecting petitioner's argument that the "EPA repeatedly 

stymied [the petitioner's] access to the [EPA]'s . . . 

15 The Petitioners cite Home Box Office, Inc. v. FCC, 567 

F.2d 9 (D.C. Cir. 1977), for the proposition that "the public 

record must reflect what representations were made to an agency" 

and that "communications [cannot be] made to [an] agency in 

secret." Id. at 54. But that case involved ex parte 

communications made to an agency after it proposed a rulemaking, 

see id. at 51-53, and the D.C. Circuit specifically stated that 

"communications which are received prior to" such a proposal "do 

not, in general, have to be put in a public file," id. at 57 

(emphasis added). And in any event, the holding of Home Box Office

has since been limited to ex parte communications occurring in 

rulemaking proceedings that involve "competing claims to a 

valuable privilege." Action for Child.'s Television v. FCC, 564 

F.2d 458, 477 (D.C. Cir. 1977) (citing Home Box Off., 567 F.2d at 

61 (MacKinnon, J., concurring specially)).
- 32 -

documentation" because the petitioner did "not argue that the EPA 

ran afoul of any applicable legal requirement"); id. ("[B]ecause 

the [petitioner] fails to show that it was procedurally entitled 

to anything more than what the EPA afforded it, we do not find the 

EPA's actions in this respect to have been arbitrary or 

capricious.").

Nor is there any purchase to the Petitioners' argument 

that the Settlement rendered the notice-and-comment period a 

"façade." Importantly, as the Petitioners concede, the Settlement 

did not legally constrain the EPA in deciding what provisions to 

include in the final permit. Compare Nat. Res. Def. Council, 

Inc. v. U.S. EPA, 859 F.2d 156, 194 (D.C. Cir. 1988) (discussing 

a settlement in which the EPA "bound itself only to propose

regulations," but "never bound itself as to the content of the 

final regulations," thus ameliorating concerns about whether the 

EPA had a "mind[] open to whatever insights the comments 

produced"), with Nat'l Audubon Soc., Inc. v. Watt, 678 F.2d 299, 

311 (D.C. Cir. 1982) (declining to consider whether the "government 

may enter into judicially enforceable contracts relinquishing or 

limiting its policymaking discretion"). On the contrary, the 

Settlement expressly provided that the proposed remedy would be 

"subject to a regulatory public comment process," and the 

signatories reserved the right to challenge the final permit if it 

was "inconsistent with the terms of th[e] Settlement." Following 
- 33 -

the issuance of the draft permit in July 2020, the EPA conducted 

a 67-day public comment period and then made various changes to 

the permit based on the comments. The EPA also responded to the 

comments, articulating its rationales for either implementing or 

declining to implement the commenters' suggestions. Notably, GE 

filed a comment requesting revisions to portions of the draft 

permit that GE believed were inconsistent with the Settlement, but 

the EPA declined to incorporate various of those revisions.

The Petitioners offer no evidence that the EPA did not 

follow proper procedures in considering the commenters' various 

suggestions and selecting which ones to incorporate into the final 

permit. Cf. U.S. Postal Serv. v. Gregory, 534 U.S. 1, 10 (2001) 

(noting that courts attach a "presumption of regularity . . . to 

the actions of [g]overnment agencies" when evaluating the 

"fairness of [those agencies'] own procedure[s]"). And the fact 

that the 2020 Permit ultimately included the same major provisions 

as the draft permit does not support a finding that the 2020 Permit 

should be set aside. See Biden v. Texas, 142 S. Ct. 2528, 2547 

(2022) (rejecting "criticisms of agency closemindedness based on 

an identity between proposed and final agency action"). We thus 

see no reason to conclude that the Settlement rendered the noticeand-comment process a "façade."16 Our conclusion is consistent 

16 Contrary to the Petitioners' intimations, GE's agreement 

under the Settlement to make payments, donations, and other 
- 34 -

with cases confronting agency settlement agreements in roughly 

similar contexts. See Citizens for a Better Env't v. Gorsuch, 718 

F.2d 1117, 1120-21, 1127-30 (D.C. Cir. 1983) (upholding a 

settlement in which the EPA agreed to promulgate certain 

regulations, where the settlement "did not specify the substantive 

result of any regulations [the] EPA was to propose and only 

required [the] EPA to initiate 'regulatory action'" subject to 

"full notice and comment"); Save Our Sound OBX, Inc. v. N.C. Dep't 

of Transp., 914 F.3d 213, 226 (4th Cir. 2019) (upholding a 

settlement that required an agency to identify a course of action 

as the "preferred alternative" but did not require selecting that 

action as the "final approved alternative").17

concessions to several other stakeholders does not compel such a 

conclusion. Those covenants of the Settlement -- which largely 

concerned funding for economic development and aesthetic and 

recreational improvements -- ran solely between GE and the City of 

Pittsfield, the Massachusetts Audubon Society, and the five towns 

comprising the Municipal Committee. They were not embodied in the 

draft permit or the 2020 Permit, and no payments were made to the 

EPA. The Petitioners offer no reason to believe that the payments 

influenced the EPA's decisionmaking.

17 In support of their argument that the EPA predetermined 

the provisions of the 2020 Permit based on the Settlement, the 

Petitioners cite two cases involving the disqualification of an 

agency commissioner due to that commissioner's prejudging the 

outcome of a formal administrative hearing. See Cinderella Career 

and Finishing Schs., Inc. v. FTC, 425 F.2d 583, 589-92 (D.C. Cir. 

1970); Texaco, Inc. v. FTC, 336 F.2d 754, 759-60 (D.C. Cir. 1964), 

vacated on other grounds, 381 U.S. 739 (1965). Those cases' facts 

bear little resemblance to the development of the 2020 Permit, 

which was subject to public notice and comment. See Ass'n of Nat'l 

Advertisers, Inc. v. FTC, 627 F.2d 1151, 1161 (D.C. Cir. 1979) 

(limiting the application of Cinderella and Texaco to formal 

"adjudication or quasi-adjudication"). Further, the Settlement 
- 35 -

Accordingly, we conclude that the mediation and 

resulting Settlement were procedurally sound. The EPA invited to 

the mediation all of the parties that had challenged the 2016 

Permit -- GE, HRI, the Municipal Committee, the Berkshire 

Environmental Action Team, and C. Jeffrey Cook -- as well as 

Connecticut, Massachusetts, the City of Pittsfield, the 

Massachusetts Audubon Society, and HEAL. The mediation thus 

benefited from the interplay of the various and competing interests 

of environmentalists; landowners; industry representatives; and 

local, state, and federal government entities. And the mediation 

resulted in an agreement that was acceptable to all involved 

parties except for the Petitioners.18 Our "[r]espect for the 

[EPA]'s role is heightened in this situation" because a "crew of 

sophisticated players, with sharply conflicting interests, s[a]t 

at the table" and "hammered out an agreement at arm's length." 

Cannons Eng'g Corp., 899 F.2d at 84. It bears emphasizing that 

the Municipal Committee joined the Settlement through the 

signatures of the elected chairpersons of each of the five member 

towns' select boards. To the extent the Petitioners argue -- as 

here concerned only the EPA's proposed remedy, not the final 

permit. Cf. id. at 1173 ("The period before the [agency] first 

decides to take action on a perceived problem is . . . the best 

time for a rulemaker to engage in dialogue with concerned 

citizens.").

18 Although Massachusetts did not sign the Settlement, it 

did not object to it or to the 2020 Permit.
- 36 -

their counsel did at oral argument -- that the Municipal Committee 

did not speak for "the people" when signing the Settlement, that 

rhetorical flourish presents no argument to this court.

IV. Substantive Challenges to the 2020 Permit

We now turn to the Petitioners' three substantive 

challenges to the 2020 Permit. First, the Petitioners challenge 

the EPA's decision to require MNR -- rather than excavation and 

removal of contaminated sediment -- as the remedy for certain 

downstream reaches of the Rest of River. Second, the Petitioners 

contend that the EPA should have required GE to treat excavated 

and removed material with thermal desorption and/or 

bioremediation. Finally, the Petitioners challenge the 2020 

Permit's hybrid disposal approach, arguing that the EPA's 

selection of hybrid disposal constituted an arbitrary reversal of 

its previous choice to mandate fully offsite disposal in the 2016 

Permit.

Under the APA, we will set aside the EPA's actions only 

if they were "arbitrary, capricious, an abuse of discretion, or 

otherwise not in accordance with law." 5 U.S.C. § 706(2)(A). We 

leave agency actions undisturbed unless 

the agency has relied on factors which 

Congress has not intended it to consider, 

entirely failed to consider an important 

aspect of the problem, offered an explanation 

for its decision that runs counter to the 

evidence before the agency, or is so 

implausible that it could not be ascribed to 
- 37 -

a difference in view or the product of agency 

expertise.

Motor Vehicle Mfrs. Ass'n v. State Farm Mut. Auto. Ins. Co., 463 

U.S. 29, 43 (1983). "This deference goes to the entire agency 

action, which here includes both the EPA's permitting decision and 

the EAB's review and affirmance of that decision."19 Upper 

Blackstone Water Pollution Abatement Dist. v. U.S. EPA, 690 F.3d 

9, 20 (1st Cir. 2012). And "the 'scientific and technical nature 

of the EPA's decisionmaking' increases our level of deference." 

City of Taunton, 895 F.3d at 126 (quoting Upper Blackstone, 690 

F.3d at 20).

An agency may change its existing position on an issue 

"as long as [it] provide[s] a reasoned explanation for the change." 

Encino Motorcars, LLC v. Navarro, 579 U.S. 211, 221 (2016). That 

requirement "ordinarily demand[s] that [the agency] display 

awareness that it is changing position," FCC v. Fox Television 

Stations, Inc., 556 U.S. 502, 515 (2009), but does not constitute 

a "heightened standard" of review, id. at 514. The agency "need 

not demonstrate . . . that the reasons for the new policy are 

19 Because no final agency action occurred until after the 

EAB upheld the 2020 Permit, the Petitioners could not directly 

appeal the EAB's 2018 decision. See 40 C.F.R. § 124.19(l)(2) 

(specifying that final agency action does not occur when the EAB 

remands a permit, but rather only occurs once the EAB denies review 

or once remand proceedings are completed). Our review thus 

encompasses the pertinent holdings of both the 2018 and 2022 EAB 

decisions, as well as the EPA's other actions.
- 38 -

better than the reasons for the old one; it suffices that the new 

policy is permissible . . ., that there are good reasons for it, 

and that the agency believes it to be better." Id. at 515. A 

"more detailed justification" may be required, however, when the 

agency's new position "rests upon factual findings that contradict 

those which underlay [the] prior" position or when the agency's 

prior position "has engendered serious reliance interests." Id.; 

see NLRB v. Lily Transp. Corp., 853 F.3d 31, 36 (1st Cir. 2017) 

(Souter, J.) ("[A]n about-face . . . owing to facts changed from 

those underlying the prior view requires that the new facts be 

addressed explicitly by reasoned explanation for the change of 

direction."). Further, "when an agency rescinds a prior 

[position,] its reasoned analysis must consider the 

'alternative[s]' that are 'within the ambit of the existing 

[position].'" DHS v. Regents of the Univ. of Cal., 140 S. Ct. 

1891, 1913 (2020) (second alteration in original) (quoting State 

Farm, 463 U.S. at 51).

We now consider the Petitioners' three substantive 

challenges in turn.

A. Challenge to the 2020 Permit's 

Monitored Natural Recovery (MNR) Provisions

As to the 2020 Permit's provisions concerning 

remediation, the Petitioners challenge the EPA's decision to 

require MNR -- rather than excavation, removal, and capping -- for 
- 39 -

the downstream reaches of the Rest of River. The 2020 Permit's 

applicable provisions concerning MNR are unchanged from those in 

the 2016 Permit; both permits included MNR as the remedy for the 

flowing subreaches of Reach 7 and for Reaches 9 through 16.

In its response to comments on the draft version of the 

2016 Permit, the EPA explained its rationale for selecting MNR as 

the remedy for the downstream reaches. The EPA noted that "PCB 

concentrations in these . . . reaches are low and . . . diffuse 

over large areas"; that the sediment in these reaches "is 

reasonably stable"; that "[h]uman health and ecological risks" in 

these reaches "are generally low"; and that "decreasing trends in 

fish and benthic invertebrate PCB levels . . . have been observed"

in Reaches 9 through 16. The EPA concluded that MNR, coupled with 

"[l]ong-term monitoring," was an appropriate remedy for the 

downstream reaches. The EPA also noted two examples of sites where 

MNR had been used to remedy PCB contamination. See, e.g., United 

States v. P.H. Glatfelter Co., 768 F.3d 662, 666-67 (7th Cir. 2014) 

(discussing one of these sites).

Notwithstanding this explanation provided by the EPA, 

the Petitioners now raise four challenges to the 2020 Permit's MNR 

provisions. They rely on their own purported characterizations of 

the 2020 Permit to assert that (1) insufficient data concerning 

PCB concentrations in sediment existed to support the EPA's 

selection of MNR; (2) the EPA's failure to set a performance 
- 40 -

standard for PCB concentrations in sediment renders the MNR remedy 

ineffectual; (3) the 2020 Permit lacks a reasonable timeframe in 

which cleanup standards in the downstream reaches must be attained; 

and (4) the 2020 Permit fails to articulate a contingency plan 

should MNR fail to achieve adequate remediation.

At the outset, the EPA contends that the Petitioners 

waived these arguments by failing to demonstrate that the arguments 

were raised during the public comment period for the draft version 

of the 2016 Permit, and/or failing to raise them to the EAB when 

challenging the 2016 Permit. See Upper Blackstone, 690 F.3d at 30 

(finding that a petitioner waived an argument "by failing to 

present it either to the EPA . . . during the permitting process 

or during the initial round of briefing before the EAB"). As the 

EPA largely concedes, however, the Petitioners raised the 

arguments when challenging the 2020 Permit, both in their public 

comments and to the EAB.20 The EPA's waiver argument thus depends 

on the proposition that the Petitioners' raising the MNR arguments 

when challenging the 2020 Permit was insufficient to preserve those 

20 The EPA does contend that the Petitioners forfeited 

their argument concerning inadequate data, asserting that the 

Petitioners did not raise that argument until their reply brief to 

the EAB. We disagree. In their initial brief to the EAB when 

challenging the 2020 Permit, the Petitioners argued that "[i]n 

Connecticut, PCB sampling has been limited and scattershot," with 

"only 60 individual samples . . . taken" since the Consent Decree 

was entered. That statement sufficiently raised the issue to the 

EAB.
- 41 -

arguments here. Although the EAB found that "[t]he scope of [the 

EAB's] review of a revised permit following remand is limited to 

the issues the [EAB] remanded and any other changes to the permit 

made during the remand period," Gen. Elec. II, 18 E.A.D. at 664, 

we note that the EPA's regulations do not unambiguously support 

this finding, see 40 C.F.R. § 124.13 (requiring commenters to 

"raise all reasonably ascertainable issues . . . by the close of 

the public comment period"). Given this ambiguity, we choose to 

bypass the waiver issue and instead resolve the merits of the 

Petitioners' arguments, which we may do because those arguments 

fail. We now address, and reject, each of the Petitioners' four 

arguments in turn.

1. Challenge Regarding Adequacy of Baseline Data

The Petitioners first argue that the EPA analyzed an 

insufficient amount of baseline data from the Connecticut reaches 

of the Rest of River to support its selection of MNR as the remedy 

for those reaches. They contend that the 2020 Permit's MNR 

provisions thus violate the National Contingency Plan's 

requirement that the EPA "collect data necessary to adequately 

characterize the site for the purpose of developing and evaluating 

effective remedial alternatives." 40 C.F.R. § 300.430(d)(1).

As the EPA explained in its response to comments on the 

draft version of the 2016 Permit, and as the Petitioners concede, 

the EPA analyzed data from 540 sediment samples in Connecticut 
- 42 -

from 1980 through 2005. The average PCB concentration was 0.79 

ppm in samples collected prior to 1998 and 0.18 ppm in samples 

collected in 1998 or later. PCB concentrations in surface sediment 

were even lower. Those concentrations were already well below the 

1.00 ppm performance standard that the 2020 Permit sets for 

sediment in most upstream reaches where excavation and removal 

will occur, supporting the EPA's conclusion that "PCB 

concentrations are relatively very low (or not detected) and more 

widely dispersed" in Connecticut and thus that MNR is appropriate 

for those reaches. Notably, the Petitioners do not challenge the 

1.00 ppm performance standard for the upstream reaches in this 

appeal. Cf. Upper Blackstone, 690 F.3d at 28-29 (noting that when 

an agency "set[s] a numerical standard, courts will not overturn 

the agency's choice of a precise figure where it falls within a 

'zone of reasonableness'" (quoting Nat'l Mar. Safety Ass'n v. OSHA, 

649 F.3d 743, 752 (D.C. Cir. 2011))).

The Petitioners contend that the EPA's reliance on the 

Connecticut sediment samples is "unreasonable and scientifically 

invalid" because the samples are outdated and "extremely limited." 

This argument fails. "Our standard of review . . . does not 

deputize us to second-guess the EPA's choice of data, so long as 

the agency acts 'with a reasonable basis' in selecting and applying 

it." City of Taunton, 895 F.3d at 139 (quoting Upper Blackstone, 

690 F.3d at 26). The Petitioners offer no persuasive explanation 
- 43 -

for why the 540 existing sediment samples are unreliable, and do 

not identify any convincing reason to believe that PCB 

concentrations in the Connecticut reaches have increased since 

those samples were taken. We have rejected similar arguments 

concerning the EPA's choice of data in the past. See id.

(rejecting petitioner's "challenge[] [to] the facial validity 

of . . . data [relied upon by the EPA]" based on "the time that 

had elapsed since its collection," because the EPA "had good reason 

for relying on the . . . data, which drew from 22 different 

monitoring stations"); Sur Contra La Contaminación v. EPA, 202 

F.3d 443, 449 (1st Cir. 2000) (rejecting petitioner's contention 

that "the EPA relied on outdated" data and "should have relied on 

more recent data," because the EPA adequately explained that it 

had "no reason to question the continuing validity" of the data

(internal quotation marks omitted)).

2. Challenge Regarding Adequacy of Performance Standards

Next, the Petitioners assert that the EPA was required 

to set a performance standard for PCB concentration to be achieved 

in sediment in the downstream reaches where MNR is the selected 

remedy. As previously noted, the 2020 Permit sets a sediment 

performance standard of 1.00 ppm in most of the upstream reaches 

subject to excavation and removal, but because the data sampled 

from downstream reaches demonstrated that PCB concentrations in 

sediment are already below that level, the EPA elected not to 
- 44 -

require a sediment performance standard in those reaches. The 

Petitioners argue that this decision was contrary to the Consent 

Decree, which requires GE to achieve certain "[p]erformance 

[s]tandards" in the Rest of River, and to CERCLA, which requires 

remedial actions to "attain a degree of cleanup," 42 U.S.C. 

§ 9621(d)(1).

Although the 2020 Permit does not include a sediment 

performance standard for the downstream reaches subject to MNR, it 

does include two other performance standards applicable to those 

reaches. First, the 2020 Permit includes a "Downstream Transport 

Performance Standard" setting limits on the amounts of PCBs 

crossing certain monitoring areas. One of those monitoring areas 

is downstream from the flowing subreaches of Reach 7, meaning that 

the Downstream Transport Performance Standard measures PCB 

migration from those subreaches (which are subject to MNR) as well 

as all other upstream reaches.

Second, and more importantly, the 2020 Permit includes 

a "Short-Term Biota Performance Standard" requiring the cleanup to 

achieve a PCB concentration of 1.50 ppm in "fish fillet" in all 

reaches of the Rest of River, including those subject to MNR. The 

EPA's decision to select this fish tissue performance standard 

rather than a sediment performance standard is consistent with 

human health risk assessments conducted by the agency, which 

revealed that consumption of fish from the Rest of River would 
- 45 -

pose both cancer and non-cancer risks outside of an acceptable 

range, whereas direct contact with sediment did not pose 

unacceptable cancer risks and posed lesser non-cancer risks than 

fish consumption. Further, the EPA used a computerized food chain 

model to analyze the connection between PCB concentrations in 

sediment and fish tissue, and the Petitioners do not meaningfully 

contest the validity of that model. Cf. Upper Blackstone, 690 

F.3d at 27 ("The EPA is not limited to models which perfectly 

replicate real world conditions."). It is true, as the Petitioners 

emphasize, that the 2020 Permit defines MNR as a "remedy for 

contaminated sediment," but the 2020 Permit then states that MNR 

"requires monitoring the natural processes and/or concentrations 

of contaminants in surface water, sediment, or biota." (Emphasis 

added). The EPA's decision to monitor fish tissue as a proxy for 

sediment is consistent with this definition. 

Petitioners do not identify any legal requirement that 

the EPA must set performance standards specific to sediment in all 

reaches of the Rest of River. And the EPA has adequately explained 

its decision not to do so in the downstream reaches, given that 

PCB concentrations there are already below the standard set for 

upstream reaches. The EPA's choice to instead rely on the 

Downstream Transport Performance Standard and the Short-Term Biota 

Performance Standard is well-reasoned and consistent with the 

Consent Decree and CERCLA.
- 46 -

3. Alleged Lack of Timeframes to Achieve Performance Standards

Third, the Petitioners contend that the 2020 Permit does 

"not establish[] any timeframe for [MNR] to be effective, let alone 

a reasonable timeframe." They argue that the 2020 Permit thus 

violates EPA guidance documents that require MNR to attain 

"remediation objectives in a time period that is reasonable."

This argument is contrary to the record and fails to 

account for the provisions of the 2020 Permit concerning the 

Downstream Transport Performance Standard and the Short-Term Biota 

Performance Standard. As the EPA wrote in its 2014 Comparative 

Analysis, the MNR provisions of the permit will "include monitoring 

to confirm progress toward achieving cleanup levels in fish tissue 

and reducing ecological risk and downstream transport." In 

particular, the 2020 Permit requires GE to ensure that the 

Downstream Transport Performance Standard not be exceeded "in any 

three or more years within any 5-year period," and that the ShortTerm Biota Performance Standard "be achieved within 15 years" of 

the completion of certain construction-related activities and not 

be "exceeded in any two consecutive monitoring periods after" that 

15-year timeframe. The Petitioners fail to address the existence 

of these timeframes, let alone develop any argument that they are 

unreasonable.
- 47 -

4. Alleged Lack of Contingency Measures

Finally, the Petitioners argue that the 2020 Permit 

"lacks any mechanism for a contingent response if MNR is not 

adequately protective." They posit that by failing to include 

provisions concerning contingency measures, the EPA violated 

CERCLA's requirement of considering "the potential for future 

remedial action costs if the . . . remedial action in question 

were to fail." 42 U.S.C. § 9621(b)(1)(F).

Once again, this argument is inconsistent with the terms 

of the 2020 Permit. Those terms do, in fact, contemplate further 

actions if the performance standards applicable to the downstream 

reaches are not met. Under the 2020 Permit, if PCB concentrations 

fail to meet the Downstream Transport Performance Standard or the 

Short-Term Biota Performance Standard within those standards'

respective timeframes described above, GE must "evaluate and 

identify the potential cause(s) of the exceedance and 

propose . . . additional actions necessary to achieve and 

maintain" the standards. The EPA will then "determine any 

additional actions necessary to achieve and maintain" the 

standards "in accordance with the [Consent Decree]." Although the 

EAB's 2018 decision apparently imposed some limits on what 

"additional actions" the EPA can require under these provisions, 

see Gen. Elec. I, 17 E.A.D. at 517-19, the Petitioners develop no 
- 48 -

argument that those limits render the contingency response 

provisions inadequate.

Accordingly, we reject the Petitioners' challenges to 

the MNR provisions of the 2020 Permit.

B. Challenge to the EPA's Rejection of Certain Treatment 

Technologies as to Excavated Material

In their second substantive challenge to the 2020 

Permit, the Petitioners argue that the EPA should have required GE 

to apply treatment technologies to excavated and removed material 

prior to disposal, in order to reduce that material's toxicity and 

lessen the risk of PCB dispersal. Like the provisions concerning 

MNR, the relevant provisions of the 2020 Permit concerning 

treatment are unchanged from the 2016 Permit. Both permits

required the use of activated carbon or another sediment amendment 

in certain areas of the Rest of River, but do not require any 

treatment of removed material.

The Petitioners raise three challenges regarding the 

application of treatment technologies. They argue that (1) the 

EPA should have required GE to treat removed material with thermal 

desorption, (2) the EPA should have required GE to utilize 

bioremediation to treat the removed material, and (3) the EPA's 

failure to require treatment of the removed material violates 

CERCLA.21

21 The EPA contends that certain of the Petitioners' 
- 49 -

1. Challenge to the EPA's Rejection of Thermal Desorption

The Petitioners first challenge the EPA's decision not 

to require GE to treat removed sediment and soil with thermal 

desorption. This challenge fails.

The EPA studied thermal desorption in depth prior to 

issuing the 2016 Permit; in particular, in the 2014 Comparative 

Analysis, the agency discussed the performance of that treatment 

approach under the nine Selection Criteria. The 2014 Comparative 

Analysis concluded that treating removed material with thermal 

desorption could "potentially result in long-term adverse 

environmental impacts," would "produce the greatest amount of 

[greenhouse gas] emissions of any of the alternatives," and would 

require compliance with additional ARARs. The EPA also noted that 

there was "limited precedent" supporting the efficacy of using 

thermal desorption on large volumes of sediment, rendering the 

"adequacy and reliability of [thermal desorption] . . . uncertain." 

Further, treating the removed material with thermal desorption was

the "most expensive alternative." In its response to comments on 

challenges concerning treatment are waived due to the Petitioners' 

failure to demonstrate that those challenges were raised during 

the public comment period for the draft version of the 2016 Permit. 

Like the EPA's waiver argument concerning MNR, the EPA's waiver 

argument here depends on the proposition that the Petitioners' 

raising their concerns when challenging the 2020 Permit was 

insufficient to prevent waiver. We again choose to bypass that 

question and instead resolve the Petitioners' challenges on the 

merits.
- 50 -

the draft version of the 2016 Permit, the EPA reiterated that it 

elected not to require thermal desorption "[d]ue in part to its 

high cost, and the likelihood that all of the treated material 

could not be reused" but rather would need to be transported to an 

offsite landfill.

When developing the 2020 Permit, the EPA again noted 

that treating removed material with thermal desorption could 

potentially "present operational challenges and leave treatment 

residuals that would still require land disposal." In its response 

to comments on the draft version of the 2020 Permit, the EPA 

further explained that it had "not typically selected large-scale 

treatment at large sediment sites" when the "extraordinary size or 

complexity of a site makes implementation of [such] treatment 

technologies impracticable." The EPA acknowledged comments 

identifying an example of the use of thermal desorption at a large 

sediment site in Vietnam, but explained that that example did "not 

contradict" the EPA's analysis regarding the downsides of thermal 

desorption, including the need to landfill treated material. 

Further, the EPA listed various other drawbacks of thermal 

desorption, including the "[r]equirement to treat air 

emissions . . . [and] leachate produced by the process" and the 

risk of community opposition to the long-term operation of a 

treatment facility. See 42 U.S.C. § 9621(b)(2) (allowing the EPA 
- 51 -

to "take into account the degree of support" for remedial actions 

involving treatment).

The record thus demonstrates that in evaluating whether 

to require GE to treat removed material with thermal desorption, 

"the EPA neither relied on impermissible factors nor failed to 

consider a crucial aspect of the problem," and that the EPA's 

explanation for declining to require thermal desorption treatment 

"neither flouted the evidence in the record nor [was] 'so 

implausible that it could not be ascribed to a difference in view 

or the product of agency expertise.'" City of Taunton, 895 F.3d 

at 141 (quoting State Farm, 463 U.S. at 43).

2. Challenge to the EPA's Rejection of Bioremediation

The Petitioners next argue that the 2020 Permit should 

have required treatment of removed material with bioremediation. 

We reject this argument.

The EPA did not include a bioremediation alternative as 

part of the 2014 Comparative Analysis, because the EPA had 

previously concluded that there was insufficient evidence 

demonstrating that bioremediation would be suitable for

"applica[tion] to [the Rest of River's] conditions or 

contaminants." That conclusion was based, in part, on research 

indicating that "biological treatment processes ha[d] not been 

successfully demonstrated full-scale for PCBs in soil" and that 

there were various obstacles to the implementation of 
- 52 -

bioremediation, including the "[i]nability [of bioremediation] to 

achieve low . . . residual PCB concentrations" and the "[o]verall 

resistance of PCBs to microbial degradation." In its response to 

comments on the draft version of the 2016 Permit, the EPA again 

explained that there had "not been to date sufficient demonstration 

that bioremediation would be effective and meet the project goals." 

The EPA cited, as an example, the fact that a pilot bioremediation 

project had been terminated by Massachusetts due in part to 

evidence that the biological treatment had "dilut[ed] and 

redistribut[ed]" contaminants rather than reducing them. When 

responding to comments on the draft version of the 2020 Permit, 

the EPA declined to further elaborate on its analysis of that 

project, but the Petitioners develop no argument on appeal that 

the EPA's initial analysis was incorrect.

The Petitioners do not identify any impermissible 

factors in the EPA's analysis of bioremediation or point to any 

additional information about bioremediation that the EPA failed to 

consider. See State Farm, 463 U.S. at 43. We uphold the EPA's 

decision not to require GE to treat removed sediment and soil with 

bioremediation.

3. Alleged Noncompliance With 

CERCLA's Preference for Treatment

Finally, the Petitioners contend that the EPA's failure 

to require treatment of removed material was "not in accordance 
- 53 -

with law," 5 U.S.C. § 706(2)(A), because it was inconsistent with 

CERCLA's preference for "alternative treatment technologies," 42 

U.S.C. § 9621(b)(1). The relevant provision of CERCLA provides:

The [EPA] shall select a remedial action that 

is protective of human health and the 

environment, that is cost effective, and that 

utilizes permanent solutions and alternative 

treatment technologies or resource recovery 

technologies to the maximum extent 

practicable. If the [EPA] selects a remedial 

action not appropriate for a preference under 

this subsection, the [EPA] shall publish an 

explanation as to why a remedial action 

involving such reductions was not selected.

42 U.S.C. § 9621(b)(1). The Petitioners argue that by declining 

to require GE to treat removed sediment and soil with thermal 

desorption, bioremediation, or other treatment technologies, the 

2020 Permit violates CERCLA's requirement that the EPA "select a 

remedial action . . . that utilizes . . . alternative treatment 

technologies . . . to the maximum extent practicable." Id. We 

reject this argument for three reasons.

First, the 2020 Permit satisfies § 9621(b)(1)'s 

requirement that the EPA select a remedy that is both "protective 

of human health and the environment" and "cost effective." Id.; 

cf. Ohio v. U.S. EPA, 997 F.2d 1520, 1532 (D.C. Cir. 1993) (noting 

that the "statutory language [of § 9621(b)(1)] places as much 

emphasis on the selection of cost-effective remedies as it does on 

the selection of permanent remedies"). In the 2020 Comparative 

Analysis, the EPA found that its selected remedy will 
- 54 -

"provide . . . high levels of . . . protection" by transporting 

some contaminated materials to a licensed offsite facility and 

other contaminated materials to an onsite facility with a cap, 

double liner, leachate collection system, groundwater monitoring 

network, and stormwater management system. The EPA also found its 

selected remedy to be cost-effective relative to several other 

alternatives. In contrast, although the EPA found that treatment 

with thermal desorption would provide "human health protection,"

the EPA noted that such treatment could "potentially result in 

long-term adverse environmental impacts," would "produce the 

highest amount of [greenhouse gas] emissions of any of the 

alternatives," and would be the "most expensive alternative." As 

for bioremediation, the EPA found that there had "not been to date 

sufficient demonstration that bioremediation would be effective"

and that bioremediation could in fact risk "diluti[ng] and 

redistributi[ng]" contaminants.

Second, § 9621(b)(1) clearly contemplates that the EPA 

can select a remedy that does not incorporate all possible 

treatment techniques. Cf. Ohio, 997 F.2d at 1532 (noting that the 

fact that § 9621(b)(1) "mandates the achievement of multiple goals"

precludes an interpretation requiring the EPA to "select[] . . . 

permanent remedies whenever possible," because that interpretation 

would read the "mandate to select cost-effective remedies" out of 

the statute (emphasis added)). In particular, the statute allows 
- 55 -

the EPA to "select[] a remedial action not appropriate for a 

preference" for treatment if the EPA "publish[es] an explanation"

for that decision. 42 U.S.C. § 9621(b)(1). As discussed above, 

the EPA "publish[ed] . . . explanation[s]" justifying its decisions 

not to require treatment of removed material with thermal 

desorption, bioremediation, or other treatment technologies, id., 

and those explanations were not "arbitrary, capricious, an abuse 

of discretion, or otherwise not in accordance with law," 5 U.S.C. 

§ 706(2)(A).

Finally, although the 2020 Permit does not contemplate 

treatment of removed sediment and soil, it does require the 

application of alternative treatment technologies in other 

portions of the Rest of River in lieu of excavation and removal. 

In particular, the 2020 Permit requires GE to place "activated 

carbon and/or other comparable amendments" in certain portions of 

the Rest of River "to reduce the bioavailability of the remaining 

PCBs" in those areas. We thus are not confronted with a situation 

in which the EPA has entirely eschewed requiring treatment.

The EPA's choice to require the implementation of 

certain treatment technologies but not others, coupled with 

adequate explanations for rejecting certain technologies, is fully

consistent with CERCLA's preference for alternative treatment. We 

reject the Petitioners' challenges concerning the treatment of 
- 56 -

contaminated material to be excavated and removed from the Rest of 

River.

C. Challenge to the 2020 Permit's Hybrid Disposal Provisions

The Petitioners' third and final substantive challenge 

concerns the 2020 Permit's hybrid disposal provisions. Under those 

provisions, excavated materials with higher PCB concentrations 

will be transported to an offsite disposal facility, while less 

contaminated materials will be disposed of in an onsite facility 

near Woods Pond. The Petitioners argue that the EPA arbitrarily 

and capriciously changed course from its previous conclusion, 

embodied in the 2016 Permit, that all contaminated material should 

be disposed of offsite.

We first describe our scope of review as to this 

challenge. Like the EAB, we reject the Petitioners' request to 

supplement the record before us with stricken materials from a 

report that was never submitted to the EPA. We then turn to the 

merits of the Petitioners' arguments.

1. Request for Supplementation of the Record

When seeking review of the 2020 Permit by the EAB, the 

Petitioners sought to introduce a report written by a geoscientist 

named David J. DeSimone (the "DeSimone Report"). The DeSimone 

Report assesses the geological characteristics of the Woods Pond 

site, concluding that permeable sediments and rock fractures 

present the risk of PCB migration should the onsite disposal 
- 57 -

facility's double liner and leachate collection system fail. The 

Petitioners conceded to the EAB that the DeSimone Report was not 

presented to the EPA during the public comment period or otherwise 

included in the administrative record, but rather was prepared for 

litigation purposes after the EPA issued the 2020 Permit. See

Gen. Elec. II, 18 E.A.D. at 611-12, 612 n.19. The EAB allowed the 

Petitioners to add a portion of the DeSimone Report to the record, 

see id. at 613-14, but excluded most of the report, see id. at 

614-15. The EAB explained that no basis existed to allow review 

of the extra-record document, rejecting the Petitioners' argument 

that the report discussed topics that the EPA had failed to 

consider. See id.

We reject the Petitioners' contention that the EAB acted 

arbitrarily and capriciously in striking the bulk of the DeSimone 

Report from the record. The EAB explained that, with certain 

exceptions, EPA regulations circumscribe the scope of the EAB's 

review to the administrative record, see 40 C.F.R. § 124.18(a) 

(requiring the EPA to "base final permit decisions . . . on the 

administrative record"); id. § 124.18(b) (defining "administrative 

record" to include the record for the draft permit, the public 

comments on the draft permit, the EPA's responses to those 

comments, the final permit, and several other documents), and that 

the DeSimone Report was not part of that record because the "record 

[was] complete on the date the final permit [was] issued," id.
- 58 -

§ 124.18(c). See Gen. Elec. II, 18 E.A.D. at 608-11. The EAB 

then noted that even if it were to consider the DeSimone Report, 

the report did not "support[] an argument that the [EPA] did not 

consider all relevant factors," because the topic of the 

report -- i.e., soil permeability at the Woods Pond site -- had 

already been studied extensively by the EPA. Id. at 615; cf. 40 

C.F.R. § 300.825(c) (requiring, with respect to CERCLA response 

actions, agencies to consider "comments submitted . . . after the 

close of the public comment period only to the extent that the 

comments contain significant information not contained elsewhere 

in the administrative record file which could not have been 

submitted during the public comment period and which substantially 

support the need to significantly alter the response action"

(emphasis added)). The EAB provided adequate reasoning for 

declining to add most of the DeSimone Report to the record, and 

the Petitioners have "fail[ed] to convince us that the EAB acted 

arbitrarily or capriciously in policing its waiver rule." City of 

Taunton, 895 F.3d at 132; see id. ("We . . . uphold the EAB's 

decision to strike documents that the [petitioner] attempted to 

submit for the first time at the administrative appeal stage.").

The Petitioners now entreat this court to consider the 

stricken content of the DeSimone Report. "[W]hen reviewing an 

agency's decision under the arbitrary and capricious standard,

'the focal point for judicial review should be the administrative 
- 59 -

record already in existence, not some new record made initially in 

the reviewing court.'" Id. at 127 (quoting Camp v. Pitts, 411 

U.S. 138, 142 (1973)). We have, however, recognized several 

exceptions to the rule against record supplementation. For 

example, supplementation is permissible where there is a "strong 

showing of bad faith or improper behavior" by the agency. Town of 

Winthrop v. FAA, 535 F.3d 1, 14 (1st Cir. 2008) (quoting Olsen v. 

United States, 414 F.3d 144, 155 (1st Cir. 2005)). We may also 

supplement the record "to facilitate our comprehension of the 

record or the agency's decision," particularly when "highly 

technical, environmental matters" are at issue or when the agency 

has "fail[ed] to explain administrative action as to frustrate 

effective judicial review." City of Taunton, 895 F.3d at 127 

(first citing Town of Winthrop, 535 F.3d at 14; then quoting Valley 

Citizens for a Safe Env't v. Aldridge, 886 F.2d 458, 460 (1st Cir. 

1989) (Breyer, J.); and then quoting Olsen, 414 F.3d at 155-56). 

Similarly, we have noted that the Ninth Circuit allows record 

supplementation "when necessary to determine whether the agency 

considered all relevant factors in making its decision" or "when 

the agency has relied on extra-record materials." Ruskai v. 

Pistole, 775 F.3d 61, 66 (1st Cir. 2014) (quoting WildWest 

Inst. v. Bull, 547 F.3d 1162, 1176 (9th Cir. 2008)).

Notwithstanding the existence of these exceptions, 

supplementation of the administrative record is "the exception, 
- 60 -

not the rule, and is discretionary with the reviewing court." Town 

of Winthrop, 535 F.3d at 14. We decline, in our discretion, to 

allow the Petitioners' request. The topic of soil permeability is 

well-documented in the existing administrative record, such that 

the DeSimone Report is not necessary to "facilitate our 

comprehension" of that issue. City of Taunton, 895 F.3d at 127. 

Further, the record demonstrates that the EPA has already analyzed 

the geological conditions of the Woods Pond site and concluded 

that a low-permeability cap, double liner, leachate collection 

system, and groundwater monitoring network are sufficient to 

protect against PCB migration from the onsite disposal facility. 

Indeed, the Petitioners raised concerns about the "subsurface 

characteristics" of the site in their public comments, and the EPA 

directly responded to those comments. The Petitioners thus fail 

to identify any "relevant factors" raised by the DeSimone Report 

that the EPA failed to consider. Ruskai, 775 F.3d at 66 (quoting 

WildWest Inst., 547 F.3d at 1176); see Town of Winthrop, 535 F.3d 

at 15 (declining to consider a document that "elaborate[d] on 

concerns already addressed in the record" and thus would not "bear 

on . . . whether the [agency] adequately considered th[o]se 

concerns"); cf. United States v. Akzo Coatings of Am., Inc., 949 

F.2d 1409, 1429, 1431 (6th Cir. 1991) (finding that an affidavit 

concerning soil permeability offered "evidence . . . [that was] 

only 'supplementary' rather than 'new'" and thus that the "EPA 
- 61 -

would still have acted as it did even had [it] considered" that 

affidavit).

Accordingly, we base our review on the existing 

administrative record when addressing the Petitioners' arguments 

concerning the 2020 Permit's hybrid disposal provisions. We now 

turn to those arguments.

2. Challenges Regarding Hybrid Disposal

The Petitioners do not contest that the EPA "display[ed] 

awareness that it [was] changing position" when it opted to require 

hybrid disposal, rather than fully offsite disposal, in the 2020 

Permit. Fox, 556 U.S. at 515. Nor could they: the EPA expressly 

and repeatedly acknowledged that it altered the disposal 

provisions following the EAB's remand of the 2016 Permit, and the 

EPA directly compared the hybrid disposal approach to the 

previously selected fully offsite disposal approach in the 2020 

Comparative Analysis. The EPA thus "consider[ed] the 

'alternative[s]' that [were] 'within the ambit of'" the 2016 Permit 

when developing the 2020 Permit. Regents, 140 S. Ct. at 1913 

(second alteration in original) (quoting State Farm, 463 U.S. at 

51).

We note, too, that the EPA "did not merely revert back"

to the fully onsite disposal approach it had rejected in the 2014 

Comparative Analysis, but rather "devised a new scheme" of hybrid 

disposal, thus "chang[ing] the factual consequences" of the 
- 62 -

selected disposal approach. Lily Transp., 853 F.3d at 38. In 

particular, by allowing only contaminated materials with average 

PCB concentrations below 50 ppm to be disposed of in the onsite 

disposal facility, the 2020 Permit obviates the requirement that 

the onsite facility satisfy TSCA regulations governing the 

disposal of more highly contaminated substances. See 40 C.F.R. 

§ 761.75. Indeed, the EPA estimated that the average PCB 

concentration of material disposed of onsite will be less than 25 

ppm. Given that only less contaminated material will be disposed 

of onsite under the hybrid disposal approach, the EPA concluded 

that the onsite disposal facility will "not pose an unreasonable 

risk of injury to health or the environment." Id. § 761.61(c)(2). 

The EPA has thus explained how "facts changed from those underlying 

the" 2016 Permit influenced the agency's finding that the onsite 

disposal facility can attain TSCA's standards. Lily Transp., 853 

F.3d at 36; see Fox, 556 U.S. at 515. Notably, this change in 

disposal provisions responded directly to the EAB's criticism, in 

remanding the 2016 Permit, that the EPA had previously failed to 

adequately address whether an onsite disposal approach could 

satisfy TSCA requirements or qualify for a waiver of those 

requirements. See Gen. Elec. I, 17 E.A.D. at 561-69.

Nevertheless, the Petitioners maintain that the EPA has 

failed to "provide a reasoned explanation for the change" in the 

disposal approach. Encino Motorcars, 579 U.S. at 221. In 
- 63 -

particular, the Petitioners mount two challenges to the 2020 

Permit's hybrid disposal provisions. First, the Petitioners argue 

that the EPA's choice of hybrid disposal was improperly based on 

the agency's commitment to the Settlement, rather than on an 

objective weighing of the nine Selection Criteria. Second, the 

Petitioners challenge the EPA's decision to site the onsite 

disposal facility within an area designated by Massachusetts as an 

ACEC.

The EPA contends that the Petitioners waived these two 

arguments by failing to demonstrate that the arguments were raised 

during the public comment period for the draft version of the 2020 

Permit. See Upper Blackstone, 690 F.3d at 30. The Petitioners 

vigorously dispute this assertion, maintaining that their comments 

provided sufficient "notice to the EPA" concerning the substance 

of the Petitioners' challenges to the hybrid disposal provisions, 

even if the comments "d[id] not present technical or precise 

scientific or legal challenges." Adams v. U.S. EPA, 38 F.3d 43,

52 (1st Cir. 1994); see 40 C.F.R. § 124.13 (requiring commenters 

on draft RCRA permits to "raise all reasonably ascertainable issues 

and submit all reasonably available arguments supporting their 

position[s]"). We note, too, that the EPA's waiver argument 

depends on the proposition that the Petitioners have failed to 

identify any other commenters that sufficiently raised the two 

arguments to the EPA. See Adams, 38 F.3d at 52 n.7 (noting, in 
- 64 -

analogous permitting context, that "[t]he person filing the 

petition for review . . . does not necessarily have to be the 

individual who raised the issue during the comment period"); 

Masias v. EPA, 906 F.3d 1069, 1080 (D.C. Cir. 2018) ("Although 

[the petitioner] need not have personally raised his current 

objection during the comment period . . . he must point [the court] 

to a commenter who did."). Given the complexities involved in 

resolving this waiver question,22 we again elect to bypass the 

issue and instead address the Petitioners' two challenges on the 

merits.

a. Alleged Incongruity Between the Hybrid Disposal Provisions 

and the EPA's Analysis of the Nine Selection Criteria

The Petitioners first argue that the EPA's decision to 

require hybrid disposal was not a rational extension of its 

analysis of the nine Selection Criteria. In particular, the 

Petitioners contend that the EPA "reached the same ultimate 

conclusion under each of the [Selection Criteria] in [the] 2020 

[Comparative Analysis] as it had in [the] 2014 [Comparative 

Analysis]," yet selected hybrid disposal "despite almost all the 

[Selection] Criteria pointing to [fully] offsite disposal as the 

22 For example, comments filed by Massachusetts discussed 

the EPA's decision to place the onsite disposal facility in an 

ACEC, but ultimately did not object to that decision. We need not 

decide whether those comments sufficed to preserve the 

Petitioners' argument concerning the siting of the facility in an 

ACEC.
- 65 -

most favorable option." The Petitioners posit that the EPA, rather 

than objectively weighing the Selection Criteria, was overly 

"focused on how its remedy selection decision would affect the 

continued viability of the Settlement."

It is true that the EPA concluded, in the 2020 

Comparative Analysis, that fully offsite disposal would better 

meet several of the Selection Criteria than hybrid disposal. For 

example, with respect to "Control of Sources of Releases," the EPA 

found that unlike fully offsite disposal, the hybrid disposal 

approach would have a slight "potential for releases [of PCBs] to 

the Housatonic River watershed if, in the long term, the [onsite

disposal] facility . . . is not properly operated." That remote 

risk of future PCB releases, along with impacts to local habitat 

from the construction of an onsite disposal facility, also led the 

EPA to find that fully offsite disposal would outperform hybrid 

disposal as to "Long-Term Reliability and Effectiveness."23 

Further, the EPA concluded that fully offsite disposal would 

require compliance with fewer ARARs and would face fewer 

"regulatory and zoning restrictions" than hybrid disposal.

But even where fully offsite disposal would outperform 

hybrid disposal, it at best, as to those aspects, would do so by 

23 The impact on local habitat from the onsite facility's 

"operational footprint" was also considered as part of the EPA's 

analysis of "Short-Term Effectiveness."
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slim margins, and fully offsite disposal would impose detriments 

which hybrid disposal would avoid. As to "Control of Sources of 

Releases," for example, the EPA determined that both "alternatives 

[would] meet the criterion." With respect to "Long-Term 

Reliability and Effectiveness," the EPA found that the onsite 

disposal facility would "permanently isolate the [contaminated] 

materials" and in fact "be designed to be generally equivalent to 

a facility permitted to accept much higher concentration 

materials." The EPA further concluded that the short- and longterm impacts on local habitat from the construction of the onsite 

disposal facility would be minimal because the facility would be 

built at "an existing sand and gravel facility in close proximity 

to two other solid waste disposal facilities." In addition, the 

EPA noted that similar facilities are "routinely constructed and 

operated" with "techniques [that] are well known and demonstrated 

as effective." And due to the fact that the most highly

contaminated materials would be sent to an offsite facility under 

the hybrid disposal approach, the EPA found that even where fully 

offsite disposal was preferable to hybrid disposal, hybrid 

disposal was preferable to the fully onsite disposal option that 

was considered in the 2014 Comparative Analysis. Further, as the 

EPA noted, there was uncertainty as to the future availability of 

the needed capacity at offsite disposal sites.
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Importantly, the EPA also found that hybrid disposal 

would outperform fully offsite disposal in various metrics. For 

example, the hybrid disposal approach would result in fewer 

greenhouse gas emissions, involve fewer truck trips, and risk fewer 

transportation-related injuries and fatalities than fully offsite 

disposal. Further, hybrid disposal would be significantly less 

costly than fully offsite disposal. The EPA also noted that "local 

governments ha[d] documented their acceptance" of the hybrid 

disposal approach "through their acceptance of the Settlement."

As to the first of the Selection Criteria -- "Overall 

Protection of Human Health and the Environment" -- the EPA noted 

that the hybrid disposal approach was "part of a Settlement . . . 

that includes numerous enhancements to the floodplain and sediment 

remedies, an expedited start to implementation, and community 

coordination and benefits," and thus that hybrid disposal would 

"provide better short- and long-term protectiveness" than fully 

offsite disposal. That conclusion comported with the portion of 

the 2020 Comparative Analysis comparing the remediation provisions 

of the 2016 Permit with those of the draft version of the 2020 

Permit. In that part of the 2020 Comparative Analysis, the EPA 

concluded that the draft revised permit would outperform the 2016 

Permit as to the majority of the Selection Criteria due to the 

various new remedial measures included in the new permit, such as 

the requirements that GE excavate additional contaminated sediment 
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and soil from the Rest of River, remediate more than twenty 

additional residential properties, remove two dams so as to restore 

natural habitat, develop a quality-of-life plan addressing 

community impacts, and begin "investigation and design work" on 

the Settlement's effective date. The EPA thus concluded that, 

when scrutinizing the new provisions in the draft version of the 

2020 Permit holistically, "the combination of the . . . sediment 

and floodplain [revisions] and the [h]ybrid [d]isposal 

approach . . . [would be] best suited to meet the . . . Selection 

Criteria."

In light of these determinations by the EPA, we disagree 

with the Petitioners' contention that "almost all the [Selection] 

Criteria point[ed] to [fully] offsite disposal as the most 

favorable option." On the contrary, the EPA found that hybrid 

disposal would outperform fully offsite disposal on "Overall 

Protection of Human Health and the Environment," "Cost," and 

certain aspects "Short-Term Effectiveness" and "Implementability." 

The EPA found that fully offsite disposal would outperform hybrid 

disposal as to three criteria -- "Control of Sources of Releases,"

"Compliance with [ARARs]," and "Long-Term Reliability and 

Effectiveness" -- but only by slim margins.24 Given these findings 

24 The remaining two criteria -- "Attainment of Interim 

Media Protection Goals" and "Reduction of Toxicity, Mobility, or 

Volume of Wastes" -- were either inapplicable or equally satisfied 

by hybrid disposal and fully offsite disposal.
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and the EPA's explanations for them, we cannot conclude that the 

EPA acted arbitrarily or capriciously in concluding, as required 

by the Consent Decree, that the hybrid disposal approach would be 

"best suited to meet the [first three Selection Criteria] . . . in 

consideration of the [latter six Selection Criteria] . . . 

including a balancing of [the latter six Selection Criteria] 

against one another." And to the extent the 2020 Comparative 

Analysis involved factual findings that differed from those in the 

2016 Comparative Analysis -- such as the finding that the onsite 

disposal facility no longer needed to satisfy TSCA requirements 

concerning contaminated materials with PCB concentrations of 50 

ppm or greater, and the finding that there was increased community 

support for disposing of certain materials onsite -- the EPA 

provided the requisite "detailed justification" for those findings 

in light of the changed circumstances following the remand of the 

2016 Permit. Fox, 556 U.S. at 515.

We reject the Petitioners' contention that it was 

inappropriate for the EPA to consider the effects of the Settlement 

in the 2020 Comparative Analysis. The Consent Decree does not 

limit what the EPA may take into account when evaluating the nine 

Selection Criteria, and a natural reading of several of those 

criteria allows consideration of the Settlement. In particular, 

the Settlement is plainly relevant to the "Implementability"

criterion, under which the EPA analyzed various factors bearing on 
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community and governmental backing for the Rest of River cleanup. 

It was not arbitrary or capricious for the EPA to conclude that 

the broad stakeholder support for hybrid disposal would aid the 

implementation of the 2020 Permit's provisions. Nor was it 

arbitrary or capricious for the EPA to consider the 2020 Permit's 

enhanced remediation provisions in conjunction with the hybrid 

disposal approach. Nothing in the Consent Decree requires the 

Selection Criteria to be considered in a vacuum for each separate 

element of the cleanup; on the contrary, the Consent Decree broadly 

states that the EPA must determine "which corrective measure or 

combination of corrective measures" will best meet the Selection 

Criteria, "taking into consideration that the corrective measures 

ultimately selected will be implemented as a remedial action." 

(Emphasis added). It thus was not inappropriate for the EPA to 

consider the terms of the draft version of the 2020 Permit 

holistically when conducting the 2020 Comparative Analysis. That 

is especially so because the enhanced remediation provisions were 

directly tied to the hybrid disposal approach through the 

Settlement, and would likely not have been added to the revised 

permit otherwise, given that the EAB had already upheld the prior, 

less protective remediation provisions of the 2016 Permit against 

several challenges, including by HRI. See Gen. Elec. I, 17 E.A.D. 

at 487-519, 523-58.
- 71 -

The Petitioners also argue that it was inappropriate for 

the EPA to consider the fact that the Settlement expedited the 

implementation of the Rest of River cleanup, both by requiring GE 

to begin "investigation and design work" on the Settlement's 

effective date and by preventing signatories from challenging the 

2020 Permit "unless it [was] inconsistent with the terms of th[e] 

Settlement." But importantly, we are not faced here with a 

situation where an agency has cited a desire to avoid litigation 

as the sole basis for its action. Rather, the EPA considered the 

stakeholder support for the Settlement, and the accelerated start 

to implementation, as two factors among many in the 2020 

Comparative Analysis. That limited consideration of reduced 

litigation and implementation risk does not involve a "reli[ance] 

on factors which Congress has not intended [the EPA] to consider." 

State Farm, 463 U.S. at 43; see, e.g., Regents, 140 S. Ct. at 1908, 

1910 n.4 (rejecting an agency's post-hoc claim that its action was 

based on a desire to "avoid burdensome litigation," but not finding 

that considering litigation risk would have been inappropriate in 

the first instance); Omnipoint Corp. v. FCC, 78 F.3d 620, 633 (D.C. 

Cir. 1996) ("[A]n agency may properly consider the avoidance of 

litigation-related delay when revising its rules."); cf. Cannons, 

899 F.2d at 88 (noting that a "principal end" of CERCLA is the 

"achievement of prompt settlement and a concomitant head start on 

response activities"). And GE's agreement to not challenge the 
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2020 Permit was particularly salient given that it thereby 

forfeited the immediate appeal rights afforded to it by the Consent 

Decree's requiring the Rest of River remedy to be embodied in a 

RCRA permit rather than a CERCLA remedial action order. Compare

42 U.S.C. § 6976(b) (providing generally for immediate appeals of 

RCRA permits), with id. § 9613(h) (preventing most appeals of 

CERCLA remedial action orders until after the EPA has acted to 

enforce those orders).

We conclude that the EPA did not act arbitrarily or 

capriciously in weighing these various factors in the 2020 

Comparative Analysis and concluding that hybrid disposal -- along 

with the associated benefits by way of the Settlement -- better 

satisfied the Selection Criteria than fully offsite disposal.

b. Challenge to the Siting of the Onsite Disposal Facility in 

an Area of Critical Environmental Concern (ACEC)

The Petitioners' final challenge concerns the planned

location of the onsite disposal facility. Under the 2020 Permit, 

that facility will be located in a 20-acre portion of a much larger 

area designated by Massachusetts as an ACEC. A Massachusetts 

regulation provides that "[n]o site shall be determined to be 

suitable or be assigned as a solid waste management facility where 

such siting . . . would be located within an [ACEC]." 310 Mass. 

Code Regs. § 16.40(4)(d)(1). The EPA waived the applicability of 

this Massachusetts regulation, however, through a provision of 
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CERCLA that allows waiver of ARARs at a facility where "compliance 

with such [ARARs] at that facility will result in greater risk to 

human health and the environment than alternative options." 42 

U.S.C. § 9621(d)(4)(B). The Petitioners argue that the EPA's 

waiver of the Massachusetts regulation was arbitrary and 

capricious.

As we have explained, however, the EPA adequately 

explained its conclusion that hybrid disposal would better meet 

the nine Selection Criteria than fully offsite disposal. And in 

particular, the EPA supportably found that hybrid disposal would 

outperform fully offsite disposal as to the "Overall Protection of 

Human Health and the Environment" criterion. The Petitioners offer 

no reason, and we discern none, why the analysis of that criterion 

differs from the determination under CERCLA that fully offsite 

disposal would "result in greater risk to human health and the 

environment" than hybrid disposal. Id.

In particular, and as previously discussed, the EPA 

found that fully offsite disposal would result in more greenhouse 

gas emissions, involve more truck trips, and risk more 

transportation-related injuries and fatalities than hybrid 

disposal. The EPA also noted that "the capacity of the [onsite 

disposal facility] is known and is sufficient to receive [the 

requisite] volume of material" and that utilizing hybrid disposal 

would "save capacity" in offsite landfills where there are 
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"uncertainties about the future availability of necessary 

capacity." Further, the EPA determined that because the onsite 

disposal facility would be located at an "industrial and previously 

disturbed" former gravel mining pit, the facility would "not 

[cause] significant permanent loss of habitat or displacement of 

wildlife." The EPA also explained that "[p]rompt implementation 

of the [hybrid disposal] remedy [would] translate[] directly into 

reduced risks to human health and the environment, by more quickly 

addressing the risks associated with PCB contamination," and that 

the hybrid disposal provisions were associated with enhanced 

remediation measures by way of the Settlement.

The EPA did not act arbitrarily and capriciously in 

concluding, based on these myriad considerations, that a waiver of 

the Massachusetts regulation was appropriate. Notably, 

Massachusetts itself expressly stated in its public comments that 

it did "not object to . . . the waiver."

The Petitioners contend that the analysis under 

§ 9621(d)(4)(B) must be confined to local impacts, such that the 

EPA should not have "focuse[d] on the environmental risks posed to 

communities away from the [Rest of] River," including the risks 

related to the "location of the offsite disposal facility . . . 

[and] by greenhouse gases emitted in the course of offsite 

transportation." But this argument is at odds with the statutory 

text, which broadly authorizes the waiver of ARARs at a facility 
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if "compliance with such [ARARs] at that facility will result in 

greater risk to human health and the environment than alternative 

options." Id. Although the statute concerns the compliance with 

an ARAR at a specific "facility"25 -- here, the onsite disposal 

facility -- it does not likewise restrict the EPA's assessment of 

the "risk[s] to human health and the environment" to the risks 

occurring at that facility. The statutory text thus unambiguously 

allows the EPA to consider health and environmental impacts 

resulting from the compliance or noncompliance with ARARs, 

regardless of where those impacts occur.

We conclude that the 2020 Permit's provisions mandating 

hybrid disposal are not "arbitrary, capricious, an abuse of 

discretion, or otherwise not in accordance with law." 5. U.S.C. 

§ 706(2)(A).

V. Conclusion

The Petitioners' dedication to the remediation of the 

Housatonic River, and their decades of civic engagement in relation 

to that process, are commendable. We trust that the EPA will, as 

its counsel avowed at oral argument, "continue engaging with the 

communities" affected by the contamination of the Rest of River. 

We also trust that should GE fail to attain the cleanup standards 

25 CERCLA defines "facility" to include, inter alia, 

"landfill[s]" and "site[s] or area[s] where a hazardous substance 

has been deposited, stored, disposed of, or placed, or otherwise 

come to be located." 42 U.S.C. § 9601(9).
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required under the 2020 Permit, the EPA will enforce the permit's 

various contingency measures to ensure that conditions in the Rest 

of River continue to improve.

Ultimately, we conclude that the EPA's challenged 

actions -- both procedural and substantive -- were not arbitrary 

or capricious. Accordingly, the petition for review is denied.