Court Opinion

ID: 9411179
Source: CourtListenerOpinion
Date Created: 2023-07-25 22:02:13.637538+00
Date Added: 2024-06-11T17:21:05.190466
License: Public Domain

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
            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

                                       - 3 -
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

                                       - 4 -
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

                                        - 5 -
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

                                          - 6 -
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."

                                     - 7 -
               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.

                                       - 8 -
§ 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).

                                            - 9 -
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    PCB-

contaminated     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[,]

                                      - 10 -
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."

                                 - 11 -
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."

                              - 12 -
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.

                              - 13 -
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

                                 - 14 -
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

                                          - 15 -
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.

                                      - 16 -
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.

                                  - 17 -
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.

                                       - 18 -
             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,

                                    - 19 -
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

                                          - 20 -
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

                                  - 21 -
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.

                               - 22 -
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,

                                    - 23 -
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.

                                 - 24 -
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

                               - 25 -
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)

                                       - 26 -
("[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

                              - 27 -
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.

                                   - 28 -
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

                                         - 29 -
"[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

                              - 30 -
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)).

                                     - 31 -
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

                                        - 32 -
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 notice-

and-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

                                  - 33 -
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

                                      - 34 -
            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.

                                     - 35 -
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

                                    - 36 -
              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.

                                    - 37 -
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

                                      - 38 -
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

                                    - 39 -
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.

                                 - 40 -
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

                                - 41 -
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

                                - 42 -
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

                                     - 43 -
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

                                    - 44 -
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.

                                   - 45 -
 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 Short-

Term 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.

                                       - 46 -
               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

                                    - 47 -
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'

                                           - 48 -
   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.

                               - 49 -
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

                                       - 50 -
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

                                            - 51 -
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

                                  - 52 -
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

                                    - 53 -
"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

                                    - 54 -
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

                                     - 55 -
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

                                     - 56 -
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.

                                   - 57 -
§ 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

                                   - 58 -
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,

                                       - 59 -
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

                                    - 60 -
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

                                     - 61 -
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

                                       - 62 -
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

                                 - 63 -
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.

                                   - 64 -
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."

                                     - 65 -
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 long-

term 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.

                                      - 66 -
            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

                                    - 67 -
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.

                                     - 68 -
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

                                       - 69 -
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.

                                      - 70 -
           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

                                   - 71 -
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

                                  - 72 -
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

                                      - 73 -
"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

                                     - 74 -
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).

                                           - 75 -
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.

                                - 76 -