State of RI v. Env. Tech. ( 2001 )


Menu:
  •            United States Court of Appeals
    For the First Circuit
    No. 00-1234, 00-1342, 00-1343, 00-1344, 00-1345, 00-1399, 00-1400, 00-
    1401, 00-1402, 00-1403, 00-1404
    UNITED STATES OF AMERICA,
    Plaintiff, Appellee,
    v.
    WILLIAM M. DAVIS, et al.,
    Defendant, Appellee.
    ________________________
    ASHLAND, INC., et al.,
    Appellant.
    APPEAL FROM THE UNITED STATES DISTRICT COURT
    FOR THE DISTRICT OF RHODE ISLAND
    [Hon. Ernest C. Torres, U.S. District Judge]
    Before
    Lipez, Circuit Judge,
    Zobel and Woodlock, District Judges.*
    Denis V. Brenan for appellant Ashland, with whom Neal J. McNamara
    and Morgan, Lewis & Bockius LLP were on the brief; Gerald J. Petros for
    appellants Acco Bristol and Gar Electroforming Division, with whom
    Christopher R. Bush, Charles D. Blackman, and Hinckley, Allen & Snyder
    LLP were on the brief; Gregory L. Benik and Robin L. Main for
    appellants Morton International, Inc. and Perkin-Elmer Corporation,
    with whom Karen A. Mignone and McGovern Noel & Benik, Inc. were on the
    brief.
    Robert E. Maher, attorney, U.S. Department of Justice, for
    appellee United States, with whom Joan M. Pepin, Susan M. Akers, Scott
    D. Bauer, attorneys, U.S. Department of Justice, and Lois J. Schiffer,
    Assistant Attorney General, were on the brief.
    R. Bradford Fawley for appellee United Technologies Corporation,
    with whom Bruce C. Palmer, Robert A. Miller, and Downs Rachlin & Martin
    were on the brief; Alok Ahuja for appellees BFI Waste Systems of North
    America, Inc., Michael A. Macera, Robert A. Cece, and Macera Brothers
    Container Service, Inc., with whom Harold I. Kessler, Friedman &
    Kessler, William G. Beck, and Lathrop & Gage, L.C., were on the brief;
    Craig M. Scott for appellee City of New Jersey, with whom Duffy &
    Sweeney, LTD was on the brief; Mark T. Reynolds for appellee
    Electroformers, Inc., with whom Boyer, Reynolds & Demarco, LTD was on
    the brief.
    August 17, 2001
    * Of the District of Massachusetts, sitting by designation.
    Table of Contents
    I        Background
    II       The Consent Decrees
    A.     Background
    1.   Consent Decree I
    2.   Consent Decrees II, III, IV, and Capuano
    3.   The District Court Approval
    B.     Reviewing the Approval of the Consent Decree
    1.   Standard of Review
    2.   Case or Controversy
    3.   Fairness
    a.   Procedural
    b.   Substantive
    4.   Reasonableness
    5.   Statutory Fidelity
    6.   Unconstitutional Taking
    III      The Declaratory Judgment
    A.     Background on CERCLA Contribution Actions
    B.     The District Court's Declaratory Judgment Ruling
    C.     The Parties' Challenges to the Declaratory Judgment
    1.   Proof that the Defendants Disposed of Hazardous
    Waste
    a.   Ashland
    b.   Acco-Bristol
    c.   Black & Decker a/k/a Gar
    d.   Perkin-Elmer
    2.   Wilbert Jones's Testimony
    a.   Grounds for Exclusion
    b.   Grounds for Disbelieving
    -3-
    3.     Exclusion of Master Chart
    a.   Procedural Posture
    b.   Admissibility of the Chart
    4.     Proof that Defendants' Waste Caused or
    Contributed to Cleanup Costs
    5.     The Entry of a Declaratory Judgment under 
    42 U.S.C. § 9613
     (g)(2) and the Declaratory
    Judgment Act
    6.     Morton's Liability
    a.   Claims of Clearly Erroneous Factual
    Findings
    b.   Claims of Legal Error
    7.     Successor-in-Interest Liability for Gar
    8.     UTC's Appeal
    a.   The Judgment in Favor of Macera
    i.   Transporter Liability
    ii. Arranger Liability
    b.   The Judgment in Favor of the City of New
    Jersey
    c.   The Government's $6 Million Enforcement
    Costs
    IV       Conclusion
    Appendix I     A Roster of Parties, Principals, and Witnesses
    Appendix II    A Summary of Relevant Monetary Sums
    -4-
    LIPEZ, Circuit Judge. This appeal concerns the third phase
    of litigation under the Comprehensive Environmental Response,
    Compensation and Liability Act (CERCLA), 
    42 U.S.C. § 9601
     et seq.,
    stemming from the disposal of hundreds of thousands of gallons of
    hazardous waste in the late 1970s at a site in Smithfield, Rhode Island
    owned by William and Eleanor Davis. This phase concerns an action by
    United Technologies Corporation (UTC) under CERCLA's contribution
    provision, 
    42 U.S.C. § 9613
    (f). In 1995, UTC was found jointly and
    severally liable for costs incurred by the United States for the
    cleanup of the Davis site. Hoping to relieve itself of some of the
    -5-
    burden of that judgment, UTC sued several dozen other potentially
    responsible parties. Most of these parties, as well as UTC, signed
    partial consent decrees with the United States in which they agreed to
    pay a share of the cleanup costs. Several parties, however, did not
    settle, and in 1998 UTC took them to trial. One of the non-settlors,
    Ashland, Inc., appeals the district court's entry of the partial
    consent decrees. Ashland and four other non-settlors also appeal the
    court's entry following trial of a declaratory judgment holding them
    liable for disposing of hazardous waste at the Davis site and
    allocating to them shares of responsibility for cleanup costs.
    Finally, UTC appeals three aspects of the court's ruling.
    We affirm, with one exception -- a remand for clarification
    of the district court's ruling that UTC may be solely responsible for
    $6 million in government enforcement costs.
    I. Background
    We describe the facts in the light most favorable to the
    judgment.1 During the 1970s, William Davis operated a waste disposal
    site on ten acres of land in Smithfield, Rhode Island.2 In 1982, the
    1To assist the reader of this opinion, there are two appendices
    attached. The first identifies the roles of the multiple parties to
    this appeal and the roles of the key principals and witnesses. The
    second breaks down the liability and settlement amounts referred to in
    the case.
    2Forest borders the Davis site to the east and west, and wetlands
    and swamp border it to the north and south. When the United States
    filed suit in 1990, there were about 100 homes within one mile of the
    -6-
    Environmental Protection Agency (EPA) placed the Davis site on its
    National Priorities List of hazardous waste sites. After undertaking a
    remediation investigation and completing a feasibility study, the EPA
    issued a Record of Decision in 1987 describing the cleanup work that it
    deemed necessary to mitigate the environmental damage caused by the
    hazardous waste disposal.     As described by the EPA, the cleanup
    required the government to "(1) complete a water line to supply
    drinking water to areas where the drinking water wells already are
    contaminated and to areas where the contaminated groundwater plume
    threatens additional wells; (2) clean contaminated groundwater; and (3)
    excavate and clean contaminated soils that continue to contaminate the
    groundwater and other environmental media at the Site."        The EPA
    estimated the cost of this work at about $3 million for the water line,
    $13 million for groundwater cleanup, and $14 million for soil
    remediation. The government began the work of constructing water lines
    to nearby residents, but took no action on the soil or groundwater
    cleanups. See United States v. Davis, 
    11 F. Supp. 2d 183
    , 192 (D.R.I.
    1998) (Davis II).
    In 1990, the United States brought an action under 
    42 U.S.C. § 9607
     for recovery of past and future response costs at the Davis
    site. This provision of CERCLA allows the government to bring a "cost
    site, and about 3,800 residents within three miles. The site lies
    within a 20-mile radius of Providence, Rhode Island.
    -7-
    recovery action" against an owner or operator of a facility at which
    hazardous substances were disposed, against a transporter of hazardous
    waste, and against a party who arranged for the disposal or transport
    of hazardous waste. 
    42 U.S.C. § 9607
    (a).3 The government sued William
    3   Section 9607(a) states:
    Notwithstanding any other provision or
    rule of law, and subject only to the defenses set
    forth in subsection (b) of this section--
    (1) the owner and operator of a vessel
    or a facility,
    (2) any person who at the time of
    disposal of any hazardous substance owned or
    operated any facility at which such hazardous
    substances were disposed of,
    (3) any person who by contract,
    agreement, or otherwise arranged for disposal or
    treatment, or arranged with a transporter for
    transport for disposal or treatment, of hazardous
    substances owned or possessed by such person, by
    any other party or entity, at any facility or
    incineration vessel owned or operated by another
    party or entity and containing such hazardous
    substances, and
    (4) any person who accepts or accepted
    any hazardous substances for transport to
    disposal or treatment facilities, incineration
    vessels or sites selected by such person, from
    which there is a release, or a threatened release
    which causes the incurrence of response costs, of
    a hazardous substance, shall be liable for--
    (A) all costs of removal or remedial
    action incurred by the United States Government
    or a State or an Indian tribe not inconsistent
    with the national contingency plan;
    (B) any other necessary costs of
    response incurred by any other person consistent
    with the national contingency plan;
    (C) damages for injury to, destruction
    of, or loss of natural resources, including the
    reasonable costs of assessing such injury,
    -8-
    Davis as an owner-operator; Eleanor Davis as an owner; United
    Sanitation, Inc. and A. Capuano Brothers Inc. as transporters and
    arrangers; and Ciba-Geigy Corporation, Clairol Inc., Pfizer Inc., The
    Providence Journal Company, and UTC as arrangers.4
    The district court trifurcated the government's case. Phase
    I would determine whether the defendants were liable for response
    costs. Phase II would establish the amount of response costs incurred
    by the United States. Phase III, which is at issue in these appeals,
    would deal with all remaining claims, including claims for
    contribution, indemnification, and allocation of responsibility.
    In 1991, with the government's case against it pending, UTC
    sued some of its co-defendants and 88 other companies under 
    42 U.S.C. § 9613
    (f), which allows one potentially responsible party (PRP) to
    bring an action for contribution against other PRPs.5 Some of these
    destruction, or loss resulting from such a
    release; and
    (D) the costs of any health assessment
    or health effects study carried out under section
    9604(i) of this title.
    4The court at times referred to the arranger defendants as
    "generators." United States v. Davis, 
    882 F. Supp. 1217
    , 1219 (D.R.I.
    1995) (Davis I).
    5 In its original form, CERCLA did not expressly provide that a
    party who was liable for cleanup costs under § 9607 could seek
    contribution from other PRPs. See Keytronic Corp. v. United States,
    
    511 U.S. 809
    , 816 (1994). In 1986, Congress expressly created a
    "contribution action" by amending CERCLA with the Superfund Amendments
    and Reauthorization Act (SARA). 
    42 U.S.C. § 9613
    (f). Section 9613(f)
    - 9 -
    third-party defendants impleaded additional fourth-party defendants,
    bringing a total of 138 defendants into the litigation. The United
    States did not sue these parties directly.
    In a 1994 partial consent decree, Clairol Inc., Ciba-Geigy
    Corporation, Pfizer Inc., and The Providence Journal Company agreed
    collectively to pay the United States $5.625 million, plus interest
    accruing from the date of the settlement, toward the Davis site
    cleanup. UTC, however, did not settle, and the government took it to
    trial in 1995.6 After a bench trial, the district court found that UTC
    had dumped wax and solvent waste at the Davis site and held UTC jointly
    and severally liable for all past and future cleanup costs. See Davis
    I, 
    882 F. Supp. at 1225
    .
    While preserving the right to appeal that judgment, UTC
    states in relevant part:
    (1) Contribution
    Any person may seek contribution from any other person who
    is liable or potentially liable under section 9607(a) of
    this title, during or following any civil action under
    section 9606 of this title or under section 9607(a) of this
    title. Such claims shall be brought in accordance with this
    section and the Federal Rules of Civil Procedure, and shall
    be governed by Federal law. In resolving contribution
    claims, the court may allocate response costs among liable
    parties using such equitable factors as the court determines
    are appropriate.
    6 The claims against William and Eleanor Davis, United Sanitation,
    and A. Capuano Brothers were not settled "but for reasons that are not
    entirely clear . . . were held in abeyance." Davis II, 
    11 F. Supp. 2d at 186
    .
    - 10 -
    stipulated that the response costs incurred by the EPA before September
    30, 1987, and the enforcement costs incurred by the Department of
    Justice before September 30, 1994 -- the cut-off dates set by the court
    for determining the government's costs -- totaled $9.1 million. See
    
    id.
     UTC and the United States also stipulated that the $5.8 million
    ($5.625 million plus interest) paid by the four settlors would be
    deducted from UTC's liability. These stipulations eliminated the need
    for a Phase II trial.
    The case next proceeded to the Phase III claims for
    contribution, indemnification, and allocation of responsibility against
    the third and fourth-party defendants.7 By April 1996, the government
    said that it had incurred $19 million in response costs for site study
    and partial construction of waterlines and $6 million in litigation
    enforcement costs. See 
    id. at 192
    . It projected future costs of $3
    million to complete the water lines, $14 million for soil remediation,
    and $13 million for groundwater remediation, bringing the total
    response and enforcement costs at the site to $55 million.          See 
    id.
    In settlement negotiations, the government assigned PRPs to
    two groups according to their estimated share of liability, with
    settlement amounts based on the strength of the evidentiary case
    against each party. Eighty PRPs settled claims by joining one of five
    7 In August 1997, Judge Pettine took inactive senior status, and
    the case was transferred to Judge Torres, who then presided over Phase
    III of the litigation.
    - 11 -
    partial consent decrees, which also afforded the parties contribution
    protection against other PRPs. The first and largest of these consent
    decrees involved the United States, UTC, and 49 third and fourth-party
    defendants. See 
    id. at 185
    . The parties agreed to pay $13.5 million
    plus $440,000 in oversight costs, of which UTC would pay $2.8 million.
    In addition, UTC agreed to perform the soil cleanup for the Davis site.
    While the cost of the soil work was estimated at $14 million, UTC
    agreed to accept the risk that the work might in fact cost more. UTC's
    liability is reduced, however, by the other partial consent decrees,
    which provide for payments to UTC of up to $5.364 million.         The
    district court approved the consent decrees in 1998 and 1999, finding
    them fair, both procedurally and substantively, reasonable, and
    consistent with CERCLA's objectives.8 Soil remediation efforts began
    in July 1997. United States v. Davis, 
    31 F. Supp. 2d 45
    , 52 (D.R.I.
    1998) (Davis IV). To avoid recontamination, the groundwater cleanup
    will begin after the soil work is completed.
    Several defendants chose not to participate in any of the
    consent decrees. UTC prepared to try its claims for contribution
    against the non-settling defendants, including William Davis as owner
    and operator of the Davis site; Eleanor Davis as owner;
    8The consent decrees are described in greater detail in Part II
    of this opinion.
    - 12 -
    Chemical Waste Removal (CWR),9 Chemical Control Corporation (CCC),10 and
    Macera Brothers Container Service, Inc. (Macera) as transporters;11 and
    Acco Bristol Division of Babcock Industries (Acco), Ashland Chemical,
    Inc. (Ashland), Gar Electroforming Division (Gar), a/k/a Black &
    Decker,12 Perkin-Elmer Corporation (PE), Thiokol, a/k/a/ Morton
    International Inc. (Morton), and the City of New Jersey as arrangers.13
    Before trial began, the district court said that the trial would
    adjudicate UTC's "request to determine the 'equitable contribution
    share of liability' for past and future response costs at the Site."
    However, when UTC admitted at the start of trial that it had not begun
    to incur costs for soil remediation by the close of discovery, the
    9
    UTC also brought claims against CWR's principal, Emanuel Musillo,
    and against CWR's corporate predecessor and its principal, Drum
    Automation and Michael Musillo. The district court found Emanuel
    Musillo liable with CWR. The court dismissed the claims against Drum
    Automation and Michael Musillo. UTC did not appeal these rulings.
    10UTC also brought claims against CCC's principal, William
    Carracino. The district court found Carracino liable with CCC.
    11
    UTC also brought claims against BFI Waste Systems of North
    America as Macera's corporate successor.
    12UTC brought claims against Black & Decker and Electroformers as
    Gar's possible corporate successors. The district court found Black &
    Decker liable as Gar's successor and dismissed the claims against
    Electroformers. Black & Decker appeals that ruling, as we discuss
    infra.
    13UTC brought claims against several other defendants which the
    district court dismissed. UTC did not appeal these rulings.
    - 13 -
    court narrowed the trial's focus to UTC's right to contribution for
    future rather than past costs. It defined future costs as those that
    UTC had incurred since the close of discovery and those that it would
    incur as it completed the soil remediation.
    On September 28, 1998, following a 26-day bench trial, the
    court partially granted a motion for judgment made by some of the
    defendants based on partial findings pursuant to Federal Rule of Civil
    Procedure 52(c). The court ruled that while Macera had transported
    hazardous waste to the Davis site, it was not liable as a matter of law
    because UTC failed to prove that Macera "selected" Davis as a disposal
    site, as § 9607(a)(4) requires to hold a transporter of hazardous waste
    liable. See United States v. Davis, 
    20 F. Supp. 2d 326
    , 334 ( Davis
    III). The court also dismissed UTC's case against the City of New
    Jersey, finding that the city was immune from liability under 
    42 U.S.C. § 9607
    (d)(2).    
    Id. at 335
    .
    On December 15, 1998, the court issued a declaratory judgment
    holding appellants Ashland, Acco, Gar, Morton, and PE liable for
    arranging for the disposal of their waste at the Davis site.14 With the
    exception of Morton, the court allocated to each defendant a share of
    responsibility for UTC's future cleanup costs. Davis IV, 31 F. Supp.
    14The court also found William Davis liable as an owner-operator,
    Eleanor Davis liable as an owner, and CWR, CCC, and Capuano liable as
    transporters. Those parties have not appealed the judgments against
    them.
    - 14 -
    2d at 69.
    The appeals currently before us result from the district
    court's entry of the Phase III consent decrees, its rulings for some of
    the defendants pursuant to Rule 52(c), and its declaratory judgment in
    favor of UTC. Ashland appeals the district court's approval of the
    consent decrees. Ashland, Acco, Gar, Morton, and PE appeal several
    aspects of the declaratory judgment. Specifically, four appellants
    (Ashland, Acco, Gar, and PE) argue that UTC failed to prove by a
    preponderance of the evidence that they arranged for the disposal of
    waste at the Davis site. These four appellants also argue that the
    district court abused its discretion by admitting and crediting the
    testimony of CWR driver Wilbert Jones. Acco and Gar also argue that
    the district court abused its discretion by excluding a "Master Chart"
    of the parties' claims compiled by UTC's lawyers to prepare the witness
    designated by UTC to testify on behalf of the corporation pursuant to
    Federal Rule of Evidence 30(b)(6). Three appellants (Ashland, Acco,
    and Gar) contend that UTC failed to prove by a preponderance of the
    evidence that their respective waste contained hazardous substances and
    so caused the incurrence of cleanup costs. These three appellants also
    argue that the court's entry of a declaratory judgment was improper.
    Appellant Gar, a/k/a Black & Decker, challenges the court's finding of
    corporate successor liability. Finally, UTC contests the court's
    dismissal of the case against the City of New Jersey and Macera, and
    - 15 -
    its ruling that UTC was solely responsible for $6 million in government
    enforcement costs incurred during Phase I and II of the litigation. We
    will discuss each of these challenges in turn.
    II. The Consent Decrees
    A.   Background
    1. Consent Decree I
    Ashland's appeal focuses on Consent Decree I, the primary
    settlement between the United States and UTC, which began consent
    decree negotiations with the United States as an alternative to
    pursuing an appeal of the judgment in Davis I. In discussions with
    UTC, the EPA assigned possibly settling PRPs (generators and
    transporters of waste) to two groups, "carve-out" and "non-carve-out."
    The carve-out entities were deemed primarily responsible for the waste
    at the Davis site, and so were compelled to negotiate individual
    settlements with the United States. Non-carve-out third parties were
    encouraged to negotiate a possible global settlement among themselves,
    with the assistance of liaison counsel.
    On July 14, 1995, following the Phase I settlement with four
    parties, the United States offered to settle with all remaining parties
    for about $16 million plus the performance of site soil cleanup using
    low-temperature thermal desorption technology. UTC provisionally
    agreed to the United States's settlement offer and pursued its
    contribution claims.    Ultimately, UTC, carve-outs Olin Hunt and
    - 16 -
    American Cyanamid, and about fifty other parties joined this
    settlement. The parties paid a total of $13.5 million to the United
    States, plus $440,000 in oversight costs. Of that amount, Olin Hunt
    and American Cyanamid paid $2.75 million each (with some portion going
    to resolution of state claims), non-carve-out parties paid a total of
    $7.2 million, and UTC paid the remaining balance, about $2.8 million.15
    Furthermore, UTC took responsibility for the entire expense
    of site soil remediation, an estimated cost of about $14 million.
    Under the settlement, UTC and the United States each receive half of
    future contribution recoveries, with UTC's recovery capped at $5.364
    million after deducting 15 percent of contribution recoveries for
    attorneys' fees incurred in contribution litigation after March 1996.
    Finally, the settling parties received complete contribution protection
    from claims by other PRPs. Separate recoveries by the United States
    would not be subject to contribution sharing.
    While the predicted cost of cleaning up the Davis site has
    varied over the years, the most recent estimate, from 1997, took into
    account new remediation technology and set the total at $55 million.
    This amount guided the United States in determining the settlement
    amounts. In addition, the allocations to Clairol and the other parties
    15The allocation among the non-carve-outs was initially
    confidential, though the payment amounts have now been disclosed.
    - 17 -
    in the earlier Phase I, $5.625 million settlement provided a
    "benchmark" for the amounts requested from potential settlors in the
    later consent decrees.     Davis II, 
    11 F. Supp. 2d at 191
    .
    2. Consent Decrees II, III, IV and Capuano
    The remaining consent decrees included 27 additional parties
    and involved UTC's settlement of claims for contribution from other
    PRPs, resulting in some additional payments to the United States
    pursuant to UTC's agreement with the United States in Consent Decree I.
    In Consent Decree II, 23 parties paid a total of $4.135 million, with
    individual party liability detailed in briefs to the district court.
    Consent Decree III involved National Starch, which paid $5 million.
    Consent Decree IV involved a $150,000 payment by Swan Engraving and a
    $50,000 payment by Power Semiconductors.        All parties to these
    settlements received complete contribution protection from future
    claims. Finally, Capuano Brothers paid $200,000 to the government,
    plus a like amount for settlement of cleanup costs at another Superfund
    site.
    3. The District Court Approval
    To assist in its assessment of Consent Decree I, t he district
    court held a two-day hearing to determine whether the proposed
    settlement was fair, both procedurally and substantively, reasonable,
    and consistent with CERCLA's objectives. United States v. Cannons
    Eng'g Corp., 
    899 F.2d 79
    , 84 (1st Cir. 1990). Procedurally, the court
    - 18 -
    found that "[t]he negotiations were conducted openly and all parties
    were given an opportunity to participate." Davis II, 
    11 F. Supp. 2d at 189
    . Substantively, the court concluded that the consent decree met
    all requirements because the "proposed settlement reflects a rational
    method of allocating liability in a manner that reasonably approximates
    each party's share of responsibility; the method is applied
    evenhandedly with respect to all PRP's and sufficient information is
    presented to enable the Court to determine whether that has been done."
    
    Id. at 192
    .
    In assessing the reasonableness of the consent decree, the
    court's chief concern was "whether the public can be adequately
    compensated by a settlement in which the United States receives only a
    portion of the remediation cost from a party previously adjudged liable
    for the entire cost," 
    id. at 186
    , a reference to the release of UTC
    from the Phase I judgment. According to the district court, under the
    terms of the settlement the United States would receive $27.5 million,
    plus the $5.8 million from the original defendants, leaving a $21.7
    million shortfall in compensation for the projected cost of the
    cleanup. This issue distinguished the Davis case from others in which
    the United States settled before judgment.          "In those cases,
    compromising for a fraction of the response costs with a PRP that is
    potentially liable for the entire cost usually is justifiable on the
    ground that litigation might result in the United States recovering no
    - 19 -
    response costs at all."     
    Id. at 192
    .
    The court thus framed the reasonableness question in terms
    of "whether the amount by which the judgment has been discounted
    reasonably reflects the risk of reversal [on appeal]," and called this
    "a very close question." 
    Id. at 193
    . The court acknowledged some
    "remaining, albeit diminished, litigation risk associated with the
    claim against UTC." 
    Id.
     The court also suggested that concern about
    releasing UTC from the judgment was mitigated by the fact that the
    United States could still sue the non-settlors for the $21.7 million
    shortfall, but recognized that this course of action seemed to involve
    "much greater litigation risk" than simply pursuing the judgment
    against UTC.   
    Id.
    In resolving the issue, the court considered factors beyond
    an assessment of litigation risks. The court noted that "the financial
    obligations imposed on UTC are considerably greater than the
    obligations assumed by the other 'carve-out' settlors," reinforcing
    UTC's substantial responsibility. 
    Id.
     It also noted that "given the
    deference accorded to the EPA's judgment in such matters, it cannot be
    said that the proposed discount is unreasonable." 
    Id.
     The court said
    that the consent decree avoided an unduly harsh result for UTC, whereas
    the judgment would have "saddled [it], unfairly, with liability for
    remediation costs that far exceed its fair share." 
    Id.
     Acknowledging
    that UTC could pursue contribution actions against other PRPs, the
    - 20 -
    court still concluded that the consent decree was reasonable given the
    great "difficulty of establishing entitlement to contribution." 
    Id.
    Finally, the court found the consent decree to be consistent with the
    statute because it advanced "the overriding goal of promptly and
    efficiently cleaning up hazardous waste sites."        
    Id.
    Pursuant to its thorough opinion, the district court approved
    Consent Decree I on February 13, 1998, and entered final judgment on
    December 9, 1999. Consent Decrees II, III, IV and the Capuano decree
    were each summarily approved subsequently. Final judgment was also
    entered on these decrees in December 1999. On appeal, Ashland, a non-
    settling PRP, lodges numerous objections to the approval of the consent
    decrees, including a jurisdictional objection.        We assess these
    arguments.
    B. Reviewing the Approval of the Consent Decrees
    1. Standard of Review
    Considerable deference is involved in the review of CERCLA
    consent decrees. Indeed, appellate review is "encased in a double
    layer of swaddling."    Cannons, 
    899 F.2d at 84
    .      First, there is
    deference to the administrative agency's construction of the
    settlement. "That so many affected parties, themselves knowledgeable
    and represented by experienced lawyers, have hammered out an agreement
    at arm's length and advocate its embodiment in a judicial decree,
    itself deserves weight in the ensuing balance." 
    Id. at 84
    . Second, the
    - 21 -
    appellate court can only review a district court's approval of a
    consent decree for abuse of discretion, characterized by "a serious
    error of law" or a "meaningful lapse of judgment." United States v.
    Charles George Trucking, 
    34 F.3d 1081
    , 1085 (1st Cir. 1994); United
    States v. DiBiase, 
    45 F.3d 541
    , 544 (1st Cir. 1995).      "Because an
    appellate court ordinarily cannot rival a district court's mastery of
    a factually complex case -- a mastery often, as in this instance,
    acquired through painstaking involvement over many years -- the
    district court's views must also be accorded considerable respect."
    Charles George, 
    34 F.3d at 1085
    . This double deference "places a heavy
    burden on those who purpose to upset a trial judge's approval of a
    consent decree."    Cannons, 
    899 F.2d at 84
    .
    2. Case or Controversy
    As a preliminary matter, Ashland contends that the district
    court had no jurisdiction under Article III to approve the consent
    decrees because, "with the exception of UTC, the U.S. never sued any of
    the third or fourth-party defendants settling in Consent Decrees I-IV.
    Moreover, approximately 34 entities who were signatories to Consent
    Decree I were never sued by any party to this action." In Ashland's
    view, this circumstance means that there was no "case or controversy"
    to be resolved by the district court. We conclude that, even if there
    were parties not sued by the United States involved in the consent
    decrees, their inclusion would be permissible because the Supreme Court
    - 22 -
    has allowed unpleaded claims to be part of consent decrees, and thus,
    there is no "case or controversy" concern.
    In Local 93, Int'l Ass'n of Firefighters v. City of
    Cleveland, 
    478 U.S. 501
    , 525 (1986), the Supreme Court ruled that a
    consent decree must (1) spring from and serve to resolve a dispute
    within the court's subject matter jurisdiction; (2) come within the
    general scope of the case based on the pleadings; and (3) further the
    objectives of the law on which the claim is based.              Although
    Firefighters involved a challenge to the scope of a consent decree
    rather than an Article III case or controversy argument, satisfying the
    criteria set forth in that case resolves any case or controversy claim.
    The district court found that the criteria were satisfied by Consent
    Decree I:
    The United States's claims against the settling
    third and fourth-party defendants spring from and
    fall well within the scope of the controversy
    described in the pleading; . . . Furthermore, the
    United States and all of the settling PRP's are
    parties to the action16 and the consent decree
    resolves the dispute among them. Finally, . . .
    approval of the consent decree also furthers the
    objectives of CERCLA by facilitating the prompt
    and efficient remediation of a major hazardous
    waste site.
    Davis II, 
    11 F.Supp. 2d at 188
    .
    16We understand the court's reference to "parties to the action"
    to include those initially sued by the United States, defendants to the
    UTC contribution claims, as well as the numerous parties named in suits
    among the third and fourth-party defendants.
    - 23 -
    We have applied the Firefighters test in the CERCLA context
    before. In Charles George, we found that claims not expressly set out
    in the pleadings may be addressed in a consent decree as long as they
    fall within the pleadings' general scope.        
    34 F.3d at 1089-91
    .
    Likewise, unpleaded claims that could not be brought against third-
    party defendants pursuant to a case management order (CMO) were
    appropriately included in the consent decree. 
    Id. at 1091
    . Here, the
    purported failure to file complaints contemporaneous with the consent
    decrees does not defeat the legitimacy of the settlements. As we wrote
    in Charles George:
    [T]he Supreme Court has made clear that there is
    no per se prohibition against consent decrees
    that exceed the possible bounds of a decision
    issued directly by the trial court. Because a
    consent decree is animated not only by the
    parties' legal claims but also by the parties'
    consent, a court is 'not necessarily barred from
    entering a consent decree merely because the
    decree provides broader relief than the court
    could have awarded after trial.'
    
    Id. at 1091
     (quoting Firefighters, 
    478 U.S. at 525
    ).
    The district court allowed the inclusion of parties not sued
    by the United States in the consent decrees, finding that UTC's
    contribution claims "are based on the same body of evidence and raise
    the same issues as the United States' claims against the settling third
    and fourth-party defendants." Davis II, 
    11 F. Supp. 2d at 188
    . Like
    a settlement that is greater in scope than the originally pled claims,
    the inclusion of various third and fourth-party defendants, as well as
    - 24 -
    interested non-parties, is permissible pursuant to Firefighters.17
    Indeed, any conclusion to the contrary would disrupt the goals of
    CERCLA, which seeks early settlement with as many PRPs as possible to
    further expeditious remediation.
    3. Fairness
    a. Procedural
    Assessing fairness in the CERCLA settlement context has both
    procedural and substantive dimensions.       "To measure procedural
    fairness, a court should ordinarily look to the negotiation process and
    attempt to gauge its candor, openness, and bargaining balance."
    Cannons, 
    899 F.2d at 86
    . The EPA has ample authority to structure its
    settlement negotiations, including "broad discretion to structure
    classes of PRPs." 
    Id.
     A finding of procedural fairness may also be an
    acceptable proxy for substantive fairness, when other circumstantial
    indicia of fairness are present. See Charles George, 
    34 F.3d at 1089
    .
    Ashland asserts that the consent decrees failed to meet the
    criteria of procedural fairness because the establishment of party
    categories inhibited the openness of negotiations; discovery relating
    to the settlement terms was inadequate; and the United States abdicated
    to UTC its responsibility to conduct the negotiations under CERCLA.
    17 Ashland further contests the inclusion of "successors in
    interest" and "corporate affiliates" within the scope of Consent Decree
    I. Given the potential liability of such entities, this inclusion is
    appropriate.
    - 25 -
    Ashland also argues that information fundamental to evaluation of the
    consent decrees was not disclosed by the United States, including: (1)
    the United States' total past and estimated future costs of
    remediation; (2) the strength of the United States' case against each
    settlor; (3) the type, volume and toxicity of the waste for which each
    settlor was responsible and a correlation to site cleanup costs; (4)
    the formula by which the settlement amounts were calculated, and
    evidentiary support for the formula.
    These arguments are unpersuasive. All identified players in
    the hazardous waste site were notified of early opportunities for
    settlement with the United States, and later, with UTC. There is no
    reason to doubt that the consent decrees were the result of "arm's
    length, good faith bargaining" between sophisticated parties. United
    States v. Comunidades Unidas Contra la Contaminacion, 
    204 F.3d 275
    , 281
    (1st Cir. 2000). PRPs were offered the assistance of a magistrate
    judge and an alternative dispute resolution administrator in the
    negotiation   of   their   settlements.    In   addition,   the   early
    classification of carve-outs and non-carve-outs was an attempt at
    settlement management within the discretion of the United States.
    The district court also found no breach of the requirement
    for public disclosure, concluding that the parties offered "facts
    sufficient to enable one to determine whether" the terms of the
    agreement were fair. Davis II, 
    11 F. Supp. 2d at 194
    . The proposed
    - 26 -
    decrees lodged with the court "set[] forth, at length, all of the terms
    of the settlement." 
    Id.
     They were published in compliance with 
    42 U.S.C. § 9622
    (d)(2)(A)-(B), making the decrees available to non-parties
    and the public for comment in a timely manner.       Furthermore, the
    district court noted that "there is no indication that the United
    States misrepresented or withheld any material facts." 
    Id. at 189
    .
    There is no error in any of these findings. Ashland's argument that
    the identified information had to be available is not supported by the
    law, which makes significant allowances for gaps in information, given
    the sometimes impossible task of deriving this data.
    b. Substantive
    Substantive fairness involves concepts of corrective justice
    and accountability, concentrating on "the proposed allocation of
    responsibility as between settling and non-settling PRPs." Charles
    George, 
    34 F.3d at 1088
    . "[T]he proper way to gauge the adequacy of
    settlement amounts to be paid by settling PRPs is to compare the
    proportion of total projected costs to be paid by the settlors with the
    proportion of liability attributable to them." 
    Id. at 1087
    . Ashland
    asserts that the formula used by the government to assess liability
    among the carve-out and non-carve-out parties, settling or not, was
    arbitrary and capricious, unrelated to comparative fault and
    inconsistently applied across consent decrees.
    The law on this issue is clear. The EPA formula should be
    - 27 -
    upheld "so long as the agency supplies some plausible explanation for
    it, welding some reasonable linkage between factors it includes in its
    formula or scheme and the proportionate shares of the settling PRPs."
    Cannons, 
    899 F.2d at 87
    . In assessing the formula applied, the quality
    of the information available to the government and settling parties
    informs the fairness analysis because data on the total extent of harm
    and the respective liabilities of various PRPs are often unavailable.
    See 
    id. at 88
    .   Such difficulties will not preclude a court from
    entering a consent decree. See Charles George, 
    34 F.3d at 1089
    . The
    calculation of liability and the allocation of that responsibility is
    specially within the scope of the Agency's and parties' expertise. "As
    long as the data the EPA uses to apportion liability for purposes of a
    consent decree falls along the broad spectrum of plausible
    approximations, judicial intrusion is unwarranted . . . . Having
    selected a reasonable method of weighing comparative fault, the agency
    need not show that it is the best, or even the fairest, of all
    conceivable methods."     Cannons, 
    899 F.2d at 88
    .
    In this case, the EPA assessed liability based on "its
    estimate of the volume of waste attributable to each PRP." Davis II,
    11 F. Supp. at 190. The EPA also considered the strength of the cases
    against the respective PRPs, taking "into account that there was direct
    and credible evidence linking some of the PRP's to the Site and that
    the evidence with respect to other PRP's was almost entirely
    - 28 -
    circumstantial and varied in probative value." Id. The district court
    found the interplay of these factors in this case to be "rational" and
    "especially appropriate in cases like this where the wastes have been
    intermingled and it is virtually impossible to attribute discrete
    portions of the cleanup costs to particular wastes." Id. The court
    further observed that, in accord with the precedent, "assessing
    relative responsibility is an imperfect process because it requires
    subjective judgments based on evidence that is not completely developed
    and may be disputed.     However, . . . the evidence need not be
    exhaustive or conclusive in order to determine whether a proposed
    settlement is substantively fair."       Id. at 191.
    We agree with the district court's analysis supporting the
    substantive fairness of the liability allocation among carve-outs and
    non-carve-outs, settlors and non-settlors alike. In arguments before
    the district court, the government attorney and others noted that the
    settlements involved "roughly half of the parties paying somewhat more
    than half of the costs." In its decision, the district court stressed
    the parity of the amounts paid by settling PRPs and non-settling PRPs,
    both carve-outs and non-carve-outs. Davis II, 
    11 F. Supp. 2d at 191
    .
    The court wrote:
    Comparing the amounts paid by the settling
    'carve-out' PRP's to the Clairol benchmark and
    to the demands made upon the non-settling 'carve-
    out' PRP's supports the conclusion that the
    proposed settlement apportions liability in a
    manner that roughly approximates a rational
    - 29 -
    estimate of the relative responsibilities borne
    by both the settling and non-settling PRP's.
    
    Id. at 190
    .
    The court proceeded to compare the settlement offered to
    American Cyanamid and Olin Hunt with the settlements paid in the
    Clairol agreement and demands made of eight non-settling carve-out
    PRPs, all of which fell between $2.75 million and $3 million. See 
    id. at 191
    .   Interestingly, the court also noted that the government
    demanded $8.25 million from the State of New Jersey, BFI and Ashland,
    averaging to a total of $2.75 million each, though Ashland "was
    expected to pay a larger share because EPA determined that Ashland
    produced a high volume of hazardous waste and that a significant amount
    of evidence existed linking Ashland to the Davis site." 
    Id.
     at 191
    n.7. Finally, the court noted "an even closer correlation between the
    amounts paid by settling 'non-carve-out' PRP's and the amounts demanded
    from non-settling 'non-carve-out' PRP's" -- $13.5 million demanded of
    eighty-five non-carve-out PRPs, averaging $158,800 apiece, compared
    with the $7.2 million proposed settlement with forty-seven non-carve-
    out PRPs, amounting to $152,200 each. 
    Id. at 191
    . The court also
    pointed out that the allocation assessed to UTC was a considerably
    greater financial obligation than that imposed on any non-settling
    carve-out party.    See 
    id.
    In addition, the ultimate measure of accountability "is the
    extent of the overall recovery, not the amount of money paid by any
    - 30 -
    individual defendant." Charles George, 
    34 F.3d at 1086
    . Accordingly,
    a consent decree need not specify each generator's or transporter's
    degree of culpability. It is appropriate for classes of PRPs to be
    assigned aggregate settlement amounts to allocate among themselves.
    See 
    id.
       In Charles George we said: "Realistically, a government
    agency, in the midst of negotiations, is in no position to put so fine
    a point on accountability. We, therefore, endorse, in general, EPA's
    practice of negotiating with a representative group of PRPs and then
    permitting the group members to divide the burden of the settlement
    among themselves."    
    Id.
    Ashland's challenge to the group allocations in these
    settlements is meritless. Our prior observation remains pertinent:
    "[A]s is true of consent decrees generally, they are built upon
    compromise and compromise in turn is a product of judgment."
    Comunidades Unidas, 
    204 F.3d at 282
    .      We agree with the district
    court's conclusion that a "rational" method of allocating liability was
    "evenhandedly" applied.     Davis II, 
    11 F. Supp. 2d at 192
    .
    4. Reasonableness
    In considering the reasonableness of Consent Decree I, the
    district court addressed the novel issue of whether the public can be
    adequately compensated by a settlement in which the United States
    receives only a portion of the remediation cost from a party previously
    adjudged liable for the entire cost. See Davis II, 11 F. Supp. 2d at
    - 31 -
    186. Arguing that adequate compensation is not possible under such
    circumstances, Ashland asserts that the consent decrees do not comport
    with the objectives of CERCLA.
    The assessment of reasonableness focuses on several elements:
    the effectiveness of the decree as a vehicle for cleaning the
    environment; providing satisfactory public compensation for actual (and
    anticipated) costs of remediation; and accounting for the relative
    strength of the parties' litigating positions and foreseeable risks of
    loss. See Cannons, 
    899 F.2d at 89-90
    . In making these assessments, a
    court must once again allow for the agency's lack of "mathematical
    precision," as long as the figures derive from a plausible
    interpretation of the record. 
    Id. at 90
    . Furthermore, effective
    remediation demands a more pragmatic meaning than whether the
    settlement meets a scientific ideal or approximates the projected costs
    of cleanup. See Charles George, 
    34 F.3d at 1085
    ; United States v.
    Charter Int'l Oil Co., 
    83 F.3d 510
    , 521 (1st Cir. 1996) ("A district
    court's reasonableness inquiry, like that of fairness, is a pragmatic
    one."); Comunidades Unidas, 
    204 F.3d at 281
    .
    Although the UTC allocation in Consent Decree I does not pay
    for the entire expense of the cleanup, UTC assumed the full cost of
    soil remediation (mitigated by contribution from later settlors), even
    if that estimated cost ultimately exceeds projections. Furthermore,
    the consent decrees staved off litigation risks associated with the
    - 32 -
    settling parties, including a possible appeal by UTC of the judgment
    against it. See Davis II, 
    11 F. Supp. 2d at 192
    . In addition, as the
    district court observed, "fundamental fairness prohibits the imposition
    of liability that is totally disproportionate to UTC's share of
    responsibility."    
    Id. at 193
    .
    Discounts on maximum potential liability as an incentive to
    settle are considered fair and reasonable under Congress's statutory
    scheme.   See DiBiase, 
    45 F.3d at 546
    ; see also Interim CERCLA
    Settlement Policy, Environmental Protection Agency, 50 F.R. 5034
    (February 5, 1985). A PRP's assumption of open-ended risks, such as
    the full cost of a component of the cleanup, may merit a discount. See
    Cannons, 
    899 F.2d at 88
    . Also, party-specific discounts may reflect
    the chances of the United States's success in litigation against a
    given PRP. See 
    id.
     It is appropriate "to factor into the equation any
    reasonable discounts for litigation risks, time savings, and the like
    that may be justified."     Charles George, 
    34 F.3d at 1087
    .
    The United States received a significant sum from the initial
    settlors, Consent Decree I settlors and contributions from settlors in
    Consent Decrees II-IV and Capuano. Indeed, the United States fulfilled
    60 percent of its $55 million claim through the consent decrees,
    including the earlier $5.625 million settlement with Clairol and other
    parties. The United States also retains the option of pursuing future
    cost-recovery actions against other non-settling PRPs. In light of the
    - 33 -
    role of the consent decrees in expediting the remediation work, the
    substantial cost recovery by the United States, and the strength of the
    cases against the various PRPs, we agree with the district court that
    the consent decrees met the test of reasonableness.
    5. Statutory Fidelity
    The purposes of CERCLA include expeditious remediation at
    waste sites, adequate compensation to the public fisc and the
    imposition of accountability. "[I]t would disserve a principal end of
    the statute -- achievement of prompt settlement and a concomitant head
    start on response activities -- to leave matters in limbo until more
    precise information [is] amassed." Cannons, 
    899 F.2d at 88
    ; see also
    DiBiase, 
    45 F.3d at 545
     ("[S]ettlements reduce excessive litigation
    expenses and transaction costs, thereby preserving scarce resources for
    CERCLA's real goal: the expeditious cleanup of hazardous waste
    sites."). Additionally, there is a "strong public policy in favor of
    settlements, particularly in very complex and technical regulatory
    contexts." Comunidades Unidas, 
    204 F.3d at 280
    . Importantly, even
    though it was not obligated to do so, UTC began the process of remedial
    soil treatment in July 1997, well before the approval of Consent Decree
    I. This task included: excavation, removal and proper disposal of more
    than 1,000 drums of waste and 10,000 small jars, containers and vials;
    removal of more than 750,000 tires; and sampling and chemical analysis
    of over 65,000 cubic yards of soil. This head-start on repair of a
    - 34 -
    hazardous waste site is the sort of good-faith cooperation that CERCLA
    seeks to encourage via settlement. To find this progress inadequate
    would frustrate the statute's purpose.
    In asserting that the consent decrees are not faithful to the
    purposes of CERCLA, Ashland focuses on the contribution protection
    afforded the parties to the consent decrees, fearing that a handful of
    non-settlors (i.e., Ashland and the other appellants), foreclosed from
    contribution actions because they did not join the consent decrees,
    could be held liable for a disproportionate share of the $21.7 million
    in as-yet unrecovered costs if the United States pursued them in cost
    recovery actions. CERCLA provides that "[a] person who has resolved
    its liability to the United States or a State in an administrative or
    judicially approved settlement shall not be liable for claims for
    contribution regarding matters addressed in the settlement." 
    42 U.S.C. § 9613
    (f)(2); see also 42 U.S.C § 9622(f)(2). Despite this "matters
    addressed in the settlement" language of the statute, Ashland says that
    the "matters addressed" language of the decrees here is overreaching
    because they include, quoting the consent decrees, "response costs
    incurred and to be incurred by any person or entity other than the
    United States for response actions related to the site or identified in
    the remedy." Ashland complains that, "[a]s written, the 'matters
    addressed' provision of three partial consent decrees have been
    expanded to include all costs, whether the costs are incurred by the
    - 35 -
    U.S. or by a private party.    This is clearly impermissible under
    CERCLA." Facing exposure to performance of the groundwater remedy,
    which may represent 40 percent of the total site costs, Ashland worries
    that parties like itself will bear disproportionate liability because
    they are unfairly barred from seeking contribution from earlier-
    settling parties.
    The practice of encouraging early settlements by providing
    broad contribution protection is provided by statute. 
    42 U.S.C. § 9613
    (f)(2); see also Charter, 
    83 F.3d at 522
    ; UTC v. Browning-Ferris
    Ind., Inc., 
    33 F.3d 96
    , 103 (1st Cir. 1994) ("This paradigm is not a
    scrivener's accident."). CERCLA also seeks to induce settlements at
    higher amounts by allowing settlors to seek contribution from those who
    have not yet settled. See 
    42 U.S.C. § 9613
    (f)(3)(B); Charter, 
    83 F.3d at 522
    . Still, EPA policy encourages the court reviewing a consent
    decree incorporating contribution protection to seek "a demonstration
    that this result is fair to potential contribution plaintiffs whose
    rights would be extinguished." DOJ/EPA Memorandum, Defining "Matters
    Addressed" in CERCLA Settlements, March 14, 1997. In a case such as
    this, where UTC assumes an open-ended cost for soil remediation, and
    takes the lead in coordinating settlements and beginning the cleanup
    effort, the benefit of contribution protection is appropriate. Also,
    as UTC points out in its brief, Ashland's preoccupation with the
    potential of disproportionate liability "ignores the fact that UTC,
    - 36 -
    which was allocated responsibility for 1.54 percent of the liability by
    the trial court, will perform the source control remedy, which will
    amount to over one-fourth of the total costs of remediating the site."
    UTC draws from this fact an appropriate conclusion: "This comparison
    shows that CERCLA can impose harsh results on PRPs; it also shows that
    these contribution defendants [Ashland and other non-settlors] may bear
    a burden roughly comparable to that of UTC."
    The point we made in an earlier decision remains apt: "As
    to the extinguished contribution claims of non-settlors or later round
    settlors, protection against those claims was a reasonable benefit [the
    settlor] acquired in exchange for settling before those others."
    Charter, 
    83 F.3d at 522
    . The result of non-settlors possibly bearing
    disproportionate liability for the open-ended cost of remediation is
    therefore consistent with the statute's paradigm, which encourages the
    finality of early settlement.      See Browning-Ferris, 
    33 F.3d at 103
    .
    6. Unconstitutional Taking
    To the extent that CERCLA authorizes the contribution
    protection to which Ashland objects, Ashland asserts that this
    protection could result in an unconstitutional taking of the
    protectable property interests of non-settling parties because they
    will be prohibited from seeking contribution from earlier-settling
    parties. Indeed, Ashland points out, CERCLA recognizes that in a
    settlement "limiting any person's right to obtain contribution from any
    - 37 -
    party," the result could be "a taking without just compensation" under
    the Fifth Amendment.     
    42 U.S.C. § 9657
    .
    Ashland's argument in support of this takings claim is so
    perfunctorily developed that we deem it unworthy of response. See
    United States v. Zannino, 
    895 F.2d 1
    , 17 (1st Cir. 1990) ("[I]ssues
    adverted to in a perfunctory manner, unaccompanied by some effort at
    developed argumentation, are deemed waived."). In support of its
    takings argument, set forth in two-and-a-half pages at the end of an
    85-page brief, Ashland relies entirely on a brief description of the
    recent Supreme Court decision in Eastern Enterprises v. Apfel, 
    524 U.S. 498
     (1998), a case in which a deeply divided Supreme Court struck down
    retroactive application of the Coal Industry Retiree Health Benefit Act
    of 1992. The takings analysis put forth by the plurality opinion in
    that case did not command a majority of the court, a fact which, as the
    government notes in its brief, severely limits the precedential value
    of that takings analysis. See Hertz v. Woodman, 
    218 U.S. 205
    , 213-14
    (1910) ("[T]he principles of law involved not having been agreed upon
    by a majority of the court sitting prevents the case from becoming an
    authority for the determination of other cases, either in this or in
    inferior courts.") As Justice Kennedy noted in his concurring opinion
    in Eastern Enterprises, where he disavowed the takings analysis of the
    plurality: "Cases attempting to decide when a regulation becomes a
    taking are among the most litigated and perplexing in current law."
    - 38 -
    
    524 U.S. at 541
    . We will not assay the takings issue on the basis of
    the insubstantial argument put forth by Ashland.18
    III. The Declaratory Judgment
    A. Background on CERCLA Contribution Actions
    When an innocent party, usually the government, brings a cost
    recovery action under § 9607, CERCLA imposes strict liability for the
    costs of cleanup on a party found to be an owner or operator, past
    operator, transporter, or arranger. See Acushnet Co. v. Mohasco Corp.,
    
    191 F.3d 69
    , 74 (1st Cir. 1999).19 A party found liable under § 9607
    may in turn bring an action for contribution against other polluters
    under § 9613(f). In other words, while CERCLA allows for full recovery
    of costs from a party sued successfully under § 9607, it also permits
    that party to seek contribution from other parties that have helped
    create a hazardous waste problem. See Control Data Corp. v. S.C.S.C.
    Corp., 
    53 F.3d 930
    , 936 (8th Cir. 1995). The statute thus provides
    that a court may, in its discretion, "allocate response costs among
    liable parties using such equitable factors as the court determines are
    appropriate." 
    42 U.S.C. § 9613
    (f). As the Ninth Circuit has said,
    "[a] PRP's contribution liability will correspond to that party's
    18We note that the Sixth Circuit recently rejected a takings
    argument addressed to CERCLA and premised on Eastern Enterprises in
    Franklin County Convention Facilities Auth. v. Am. Premier
    Underwriters, Inc., 
    240 F.3d 534
    , 552 (6th Cir. 2001).
    19 A few affirmative defenses are available, but they are
    difficult to satisfy. See Acushnet, 
    191 F.3d at 74
    .
    - 39 -
    equitable share of the total liability and will not be joint and
    several." Pinal Creek Group v. Newmont Mining Corp., 
    188 F.3d 1298
    ,
    1301 (9th Cir. 1997).
    The standard for contribution liability is the same as the
    standard for cost recovery liability. See Acushnet, 
    191 F.3d at 75
    .
    A plaintiff seeking contribution under § 9613(f) must prove that (1)
    the defendant falls within one of the four categories of covered
    entities (i.e. is a current or past owner or operator, a transporter,
    or an arranger); (2) a "release or threatened release" of hazardous
    waste involving the defendant's facility occurred; (3) the release or
    threatened release caused the incurrence of response costs by the
    plaintiff; and (4) the plaintiff's costs were "necessary costs of
    response . . . consistent with the national contingency plan." 
    42 U.S.C. § 9607.20
    B. The District Court's Declaratory Judgment Ruling
    The district court found that UTC had unquestionably proven
    that the Davis site was a hazardous waste facility, that a release of
    hazardous waste had occurred, and that this release caused the
    incurrence of response costs because of the necessary cleanup. The
    20 The National Contingency Plan promulgated by the EPA, 40 C.F.R.
    pt. 300 (1988), "establish[es] procedures and standards for responding
    to releases of hazardous substances." Because the district court
    reserved challenges to UTC's specific expenditures for later
    proceedings, the compliance of UTC's cleanup plan with the National
    Contingency Plan is not at issue in this case.
    - 40 -
    court thus focused on the only remaining issue for CERCLA liability:
    "[W]hether the defendants are liable for those response costs on the
    grounds that they either operated the facility, transported the
    hazardous substances to the site, or arranged for the hazardous
    substances to be disposed of at the Site." Davis IV, 
    31 F. Supp. 2d at 61
    . Since each of the appellants was found to be an arranger, we focus
    on that aspect of the court's ruling.
    The court began by considering the evidence that CWR, the
    Bridgeport, Connecticut waste transport company used by Ashland, Acco,
    Gar, and PE, disposed of waste at the Davis site. The court found that
    in 1977, "all of CWR's waste was taken, initially, to Sanitary
    Landfill," another Rhode Island disposal site, but that sometime after
    May 1977, Anthony and Jack Capuano, owners of Sanitary Landfill, began
    diverting some of CWR's waste to the Davis site. 
    Id. at 53
    . Based on
    receipts kept by William Davis and offered into evidence by UTC, the
    court found that "the Capuanos directed CWR drivers to the Davis Site
    on fifteen separate occasions." 
    Id.
     The Davis receipts show that
    these CWR deliveries took place between May 13 and July 7.21
    The court said that CWR had two drivers, Wilbert Jones and
    Johnny Granfield, who collected 55-gallon drums of waste from
    21Davis testified that dumping occurred on his property between
    1976 and the first part of 1977. However, he was only able to locate
    receipts for the period between January 10, 1977 and July 7, 1977. As
    a result, that is the time period relevant to the district court's
    findings.
    - 41 -
    customers. Both Jones and Granfield sometimes drove a 40-foot flatbed
    truck that carried a full load of 79 drums and was "used to haul drums
    to Rhode Island." 
    Id. at 52-53
    . Based on the testimony of Jones and
    of Emanuel and Michael Musillo, the principals of CWR, the court made
    findings about CWR's pickup and disposal practices:
    If a full load was collected early in the day,
    the drums, sometimes, would be taken directly to
    Sanitary Landfill. Usually, however, the truck
    would return to CWR, and the load of drums would
    be taken to Sanitary Landfill on the following
    day. If less than a full load was collected, the
    drums would be kept at CWR until seventy-nine
    drums had accumulated. Those drums then would be
    loaded onto the flatbed and driven to Sanitary
    Landfill.
    Drums were collected with such regularity that
    they never remained on CWR's premises for more
    than three days.
    
    Id. at 53
    .
    Following the theory that CWR disposed of waste within three
    days of collecting it from a customer, the district court matched the
    dates of CWR waste pickups from appellants Ashland, Acco, Gar, and PE
    to the dates of waste deliveries to the Davis site. CWR kept bills of
    lading that recorded the dates on which it picked up wastes from
    customers. Some of the appellants kept parallel invoices. William
    Davis's receipts included the dates of waste deliveries. Based on this
    evidence, the district court determined when an arranger's waste was
    picked up within three days of a delivery to the Davis site. The court
    then concluded that it was "reasonable to infer" that this waste was in
    - 42 -
    fact disposed of at the Davis site. 
    Id. at 56
    . For example, the court
    held Ashland liable for a 79-drum load that CWR picked up from Ashland
    on June 1, 1977 because a Davis receipt showed that CWR driver Wilbert
    Jones delivered 79 drums to Davis on June 2.        
    Id.
    The court next turned to allegations that transporter CCC,
    the company used by Morton, disposed of waste at the Davis site. The
    court found that CCC made 47 trips to the Davis site between May 1977
    and the first week of July and that Morton's waste was included in some
    of those deliveries.     
    Id. at 55
    .
    Finally, the district court allocated responsibility for
    cleanup costs that UTC had incurred or would incur in completing the
    soil remediation. The chief factor in the court's determination was
    the volume of waste disposed at the Davis site that could be attributed
    to each defendant based on the evidence about specific deliveries.
    Davis IV, 
    31 F. Supp. 2d at 64
    . For example, the court found that CWR
    made two 79-drum deliveries containing 8,690 gallons of Ashland's waste
    to the Davis site, and so allocated to Ashland a share of
    responsibility for cleanup costs based on that volume. 
    Id. at 67
    .
    Based on its calculations of waste volume, the court allocated 1.03
    percent of UTC's future cleanup costs to Ashland, .16 percent to Acco,
    .03 percent to Gar, and .57 percent to PE. 
    Id. at 69
    . The court also
    allocated 1.54 percent of responsibility to UTC. 
    Id.
     Because the
    court found no evidence of specific deliveries yielding data about the
    - 43 -
    volume of Morton waste disposed, it did not allocate a share of future
    cleanup costs to Morton.     
    Id. at 65
    .
    C. The Parties' Challenges to the Declaratory Judgment
    1. Proof that the Defendants Disposed of Hazardous Waste
    We review the district court's factual findings pursuant to
    a clear error standard. See Dedham Water Co., Inc. v. Cumberland Farms
    Dairy, Inc., 
    972 F.2d 453
    , 457 (1st Cir. 1992). Clear error review
    means that:
    Findings of fact will be given effect unless,
    after reading the record with care and making due
    allowance for the trier's superior ability to
    gauge credibility, the reviewing court form [sic]
    a strong, unyielding belief that a mistake has
    been made . . . . The same high level of respect
    attaches whether the conclusions of the trial
    court depend on its election among conflicting
    facts or its choice of which competing inferences
    to draw from undisputed basic facts.
    
    Id.
     (internal quotation marks omitted). Importantly for this case,
    "[w]hen the evidence supports conflicting inferences, the district
    court's choice from among the several inferences cannot be clearly
    erroneous." 
    Id. at 462
    . We also note that findings of fact, even if
    brief, are sufficient as long as they permit a clear understanding of
    the grounds for the decision below. See Applewood Landscape & Nursery
    Co., Inc. v. Hollingsworth, 
    884 F.2d 1502
    , 1503 (1st Cir. 1989). With
    those standards in mind, we address each party's claims separately.
    a. Ashland
    In 1977, Ashland operated a chemical manufacturing plant in
    - 44 -
    Great Meadows, New Jersey, generating waste that contained nitrating
    acid, sulfuric acid, nitric acid, and solvents composed of isopropyl
    alcohol, methyl alcohol, toluene, benzene, and xylene.           It is
    undisputed that Ashland contracted with CWR to dispose of this waste,
    and the record supports the district court's finding that CWR
    transported waste to the Davis site. While Michael Musillo of CWR
    testified that between 1975 and 1977 the company took all of its waste
    initially to the Sanitary Landfill owned by the Capuanos, Jack Capuano
    testified that after April 1977, when the landfill began getting
    complaints about odor, his brother Anthony Capuano began diverting some
    of CWR's waste to the Davis site.
    CWR's pickup slips and billing records, as well as Ashland's
    disposal logs, show that during May and June of 1977, CWR picked up
    thirteen tanker loads and four flatbed loads from Ashland. Each of the
    flatbed loads contained 79 55-gallon drums. One of the flatbed pickups
    took place on June 1 and another occurred on June 30. Davis receipts
    bearing the name "Capuano," signed by Wilbert Jones, and recording 79-
    drum loads, show that CWR deliveries were diverted from Sanitary
    Landfill to the Davis site on June 2 and July 5. Based on its theory
    that CWR delivered its waste within three days of accumulating a full
    flatbed load, and the explanation that the intervening weekend and July
    4th holiday accounted for the five-day gap between June 30 and July 5,
    the district court found Ashland liable for the waste that CWR
    - 45 -
    delivered to the Davis site on June 2 and July 5.
    There is evidence in the record to support the court's
    conclusion. Emanuel Musillo, principal of CWR, testified that when a
    driver picked up a full 79-drum load early in the day, he would go
    straight to Rhode Island to dispose of it. When a driver picked up a
    full load late in the day or picked up only a partial load, he would
    park the load at CWR overnight. The next day the driver would either
    continue to Rhode Island if the truck was full, or collect waste from
    another customer if it was not. While Musillo did not definitively
    testify that CWR always delivered waste within three days of collecting
    it, he said that when a driver accumulated a full 79-drum load, the
    drums would be taken to Rhode Island "within a few days, I would
    imagine." CWR driver Wilbert Jones also testified that after picking
    up a complete load, he would leave it at CWR overnight and then leave
    for Rhode Island early the next morning.
    Ashland challenges the court's factual findings on several
    grounds.22 Ashland begins by pointing out that UTC presented no direct
    evidence, such as drums or other containers bearing Ashland's name and
    22Ashland titles the section of its brief challenging the district
    court's factual findings "As a Matter of Law, Ashland Could not Be
    Found Liable."      This attempt to win de novo review fails.
    "[A]ppellant's plaint boils down to little more than thinly veiled
    dissatisfaction with the district court's factual findings." Dedham
    Water, 
    972 F.2d at 460
    . Ashland's alternate theories about why the
    court should have made other findings and inferences are factual rather
    than legal theories and so are subject to the clear error standard.
    - 46 -
    found at the Davis site, to show that Ashland's waste was on the CWR
    deliveries to the Davis site.     While Ashland is correct, direct
    evidence is not a prerequisite to proving the elements of liability in
    a contribution action. See 
    42 U.S.C. § 9613
    (f) (setting forth elements
    of liability).
    To attack the district court's finding that CWR disposed of
    waste within three days of collecting it, Ashland offers alternative
    scenarios.   Ashland's most plausible theory is based on Jones's
    testimony that the Musillos sometimes "offloaded" nonflammable liquid
    waste by pouring it from drums into a tanker truck or underground
    storage facility at CWR.23 Ashland argues that its waste thus was
    likely unloaded at CWR's Bridgeport site after pickup and either mixed
    with other waste or stored there for an indefinite period.
    Additional testimony by Jones and the Musillos calls this
    theory into question. Jones was asked this question: "[L]et's suppose
    that you brought back some drums from one or more customers to
    Bridgeport, and that you offloaded those drums. Let's say it wasn't a
    full load. Typically, how long would it take before those offloaded
    23 Jones said in response to a question about whether CWR mixed
    waste collected at different times: "Things, anything that could be
    mixed and wouldn't explode, catch a fire, put it in the tanker. Then
    when the tanker is full take it to Rhode Island." Jones also said "if
    there was, let's say, an overflow of drums, there were more pickups to
    be made, and we couldn't handle it because the truck was full, and they
    had to be made, we would take them off, put them in the warehouse until
    we get a trip to go up to Rhode Island."
    - 47 -
    drums would find their way to Rhode Island to be dumped?" Jones
    answered: "No more than three days."       Jones also said that the
    Musillos, not he, did most of the mixing work.        Emanuel Musillo
    testified that offloading was not CWR's normal practice because of the
    "double work" involved. He said that when drums were offloaded, they
    usually contained waste oil that CWR could resell. Musillo also said
    that occasionally other kinds of waste were stored at CWR, but only
    until the next delivery trip to Rhode Island.        Michael Musillo
    corroborated aspects of his brother's account.
    In light of this testimony, the district court did not err
    in finding that it was more likely than not that the waste CWR
    collected from Ashland on June 1 and June 30 was the waste the
    transporter delivered to the Davis site on June 2 and July 5. Since
    both pickups from Ashland were full 79-drum loads, it seems
    particularly unlikely that CWR drivers would have taken a full load off
    the flatbed truck on one day, only to deliver a full load of different
    drums to the Davis site on the next business day.           Ashland's
    alternative scenarios are simply "competing inferences" that the
    district court chose not to draw. Dedham Water, 
    972 F.2d at 457
    . Such
    a choice cannot be clear error.
    Ashland's other alternative scenarios also run afoul of the
    clear error standard. First, Ashland argues that CWR often kept waste
    at its Bridgeport facility for unspecified periods, making it unlikely
    - 48 -
    that the transporter delivered Ashland's waste to the Davis site within
    three days of collecting it. Ashland cites evidence that 13,000 drums
    of waste were stockpiled at CWR in the fall of 1977. However, since
    Emanuel Musillo testified that stockpiling did not begin until CWR's
    disposal sites were shut down after the summer of 1977, the evidence on
    this point does not undermine the district court's findings. Second,
    Ashland argues that the June 2 and July 5 disposals that CWR made at
    Davis likely contained waste generated by an unknown source that CWR
    picked up from an unidentified parking lot in the New Jersey
    Meadowlands. While Jones testified that he picked up drum loads of
    waste from a parking lot somewhere in the Meadowlands not "more than
    eight or ten times" during 1977, he did not remember the dates of those
    pickups. His testimony thus lacks the specifics necessary to link the
    Meadowlands pickups to the June 2 and July 5 deliveries to the Davis
    site. Finally, Ashland argues that the June 2 and July 5 disposals
    contained waste that CWR picked up from CCC customers. There is no
    evidence to show that CWR picked up waste for CCC during the relevant
    time period.24
    24  Ashland and PE also argue that the district court's finding
    that CWR had an established practice of delivering waste within three
    days of collecting it conflicts with United States v. Newman, 
    982 F.2d 665
     (1st Cir. 1992). However, Newman is inapposite to the case at
    hand. In that case, we held that a trial judge did not abuse his
    discretion by excluding material habit evidence under Federal Rule of
    Evidence 406 when that evidence "did not require the conclusion that
    the putative practice was followed with the necessary regularity." 
    Id. at 669
     (emphasis added). Newman thus concerns the standards for the
    - 49 -
    In short, while the testimony by Jones and the Musillos
    contains some minor ambiguities, the district court did not err by
    inferring that CWR regularly disposed of waste within three days of
    collecting it, or by inferring that CWR transported Ashland's waste to
    the Davis site on June 2 and July 5.25
    b. Acco-Bristol
    admission of habit or routine practice. Here, by contrast, the
    testimony from the Musillos and Jones was admitted without objection by
    the appellants, who now argue that this evidence is not sufficient to
    establish CWR's pickup and delivery practices. This argument fails.
    Once routine practice evidence has been admitted, Rule 406 does not
    limit the district court's consideration of such evidence, or the
    weight that it may be given.
    25Ashlandalso mounts a misnomer defense, arguing that UTC did not
    name the proper party in its pleadings when it sued "Ashland Chemical
    Inc." rather than "Ashland Chemical Co." According to stipulations of
    fact by the parties, Ashland Chemical Inc. was incorporated in 1989 and
    merged into Ashland Oil Inc. in 1993. In 1996, Ashland Oil Inc.
    changed its name to Ashland Inc. Ashland Chemical Co., which operated
    the Great Meadows, New Jersey facility from which CWR transported
    hazardous waste, was a division of Ashland Oil Inc. in 1977. While
    Ashland Chemical Inc. may technically be an inaccurate reference to
    Ashland Chemical Co., there is no question that Ashland received
    adequate notice that it was being sued, and that it owned the Great
    Meadows facility from which the liability at issue here stemmed. Cf.
    Fed. R. Civ. Proc. 15(c)(3), Advisory Committee Notes 1991 Amendment
    ("An intended defendant who is notified of an action within the period
    allowed . . . for service of a summons and complaint may not under the
    revised rule defeat the action on account of a defect in the pleading
    with respect to the defendant's name . . . . [A] complaint may be
    amended at any time to correct a formal defect such as a misnomer or
    misidentification."); Hill v. Shelander, 
    924 F.2d 1370
    , 1374 n.2 (7th
    Cir. 1991) ("Plainly, the new language [of Rule 15(c)(3)] comprehends
    a situation where the original complaint sues the correct party but
    identifies him by a technically incorrect name."). There is no
    question here that UTC sued the correct party and that judgment was
    entered against that party. As a result, we reject Ashland's misnomer
    defense.
    - 50 -
    Acco-Bristol Division of Babcock Industries maintained a
    manufacturing facility in Waterbury, Connecticut in 1977.         This
    facility produced controls for oil and gas lines through processes
    involving electroplating, soldering, welding, and degreasing machine
    parts. Wastes produced by Acco included 1,1,1-TCA, a soap and cyanide
    waste stream, and acid sludge. Acco typically put the waste in 55-
    gallon drums for disposal.
    CWR twice picked up waste from Acco during the spring and
    summer of 1977, collecting 50 drums on April 6 26 and 24 drums on June
    28. On June 29, CWR received a check in the amount of $324 for these
    pickups.   A "Capuano Dumping Charge Slip," also dated June 29,
    indicates that CWR delivered a full load of 79 drums to the Davis site.
    The evidence at trial indicated that drivers directed to the Davis site
    by the Capuanos at Sanitary Landfill sometimes presented Capuano
    dumping receipts to William Davis. Davis testified that he used these
    slips to verify the amount of waste dumped on his property and to help
    him prepare invoices for Sanitary Landfill. In keeping with this
    practice, Davis sent a bill to Sanitary Landfill on June 29 for 79
    gallons of waste.
    Based on this evidence, the district court inferred that the
    24 drums of Acco waste went to the Davis site in CWR's shipment on June
    26 The district court declined to infer that the shipment picked
    up by CWR on April 6 went to the Davis site because there were no Davis
    slips within three days of that date.
    - 51 -
    29. We cannot conclude that this determination is clearly erroneous.
    Acco points out that on June 27 and 28, CWR picked up 99 drums of waste
    from various customers -- 20 drums more than were dumped at the Davis
    site.   However, at least 17 of those drums were picked up from
    customers who frequently disposed of waste oils. Because CWR tended to
    sell waste oil to salvagers, as we have noted, the district court's
    conclusion that the 24 drums of Acco's waste were part of the 79 drums
    sent to the Davis site on June 29 was reasonable.
    Acco argues that the district court erred in relying on the
    Capuano slip to infer the presence of Acco's waste at the Davis site
    because the slip does not specify a transporter. Specifically, Acco
    claims that CCC or another waste company, rather than CWR, Acco's only
    transporter, could have brought the waste delivered on June 29.
    However, testimony at trial makes clear that by June 1977, CCC was
    dumping waste directly at the Davis site without stopping at Sanitary
    Landfill first.   Thus, it is not likely that the June 29 Capuano
    Dumping Charge Slip accounted for waste hauled by CCC. As a result, we
    cannot say that the district court's findings that the Capuano slip
    referred to waste dumped by CWR, and that Acco's waste was part of that
    delivery, was clearly erroneous.      See Dedham Water, 
    972 F.2d at 463
    .
    c. Black & Decker a/k/a Gar
    Gar operated an electroplating business in Danbury,
    Connecticut. Its waste contained nitric acid, copper, nickel, and
    - 52 -
    cyanide. According to CWR records, the transporter picked up five
    loads of waste from Gar on May 6 (13 drums), June 20 (5 drums), June 27
    (2 drums), September 2 (7 drums), and September 30 (11 drums). A Davis
    receipt shows that on June 21, the day after the five-drum pickup, CWR
    disposed of 60 drums of waste at the Davis site.       The five drums
    collected on June 20 contained 275 gallons of waste. Based on this
    evidence, the district court found Gar liable for dumping 275 gallons
    of waste at the Davis site.
    Gar poses two challenges to the court's factual findings.27
    It notes that CWR picked up more than 300 drums28 from Connecticut and
    New Jersey customers on the three business days before June 21, and
    concludes that in light of those pickups it is not mathematically
    likely that Gar's five drums were among the 60 drums that CWR delivered
    to Davis on June 21. Admittedly, the collection of more than 300 drums
    in the days leading up to the June 21 delivery to Davis means that it
    is less likely that Gar's five drums were among those delivered than it
    is, for example, that the 79 drums picked up from Ashland on June 1
    were the 79 drums delivered to the Davis site on June 2.
    27Gar also argues, like Ashland, that there was no direct evidence
    that its waste ended up at Davis, and that CWR regularly offloaded its
    customers' waste at its property for unspecified periods of time and
    also mixed different customers' waste at its Bridgeport facility.
    These arguments fail for the same reasons discussed above.
    28Gar says that CWR picked up 352 drums on the three business days
    before the June 21 delivery. UTC counts 326 drums and 13 smaller
    containers collected between June 17 and June 22.
    - 53 -
    Nonetheless, the evidence that Gar emphasizes does not lead
    us to conclude that the district court's findings were clear error. As
    UTC points out, the Davis receipts show that CWR delivered a total of
    219 drums to the Davis site on June 21, June 22, and June 23,
    increasing the likelihood that Gar's five drums were among those
    delivered. In addition, 62 of the 300-plus drums collected on the
    preceding days came from customers that sent waste oil to CWR, and so,
    according to Emanuel Musillo's testimony, would likely have been
    offloaded and stored for resale rather than being delivered to the
    Davis site.
    To cast further doubt on the district court's findings, Gar
    points out that the Davis slip from June 21 says "SOLIDS" for solid
    waste, and that Gar produced liquid waste. Davis's testimony at trial
    undermines the significance of the solids designation. Davis said that
    he distinguished between solid and liquid waste because he poured
    liquid waste out of the barrels and resold them. Because he could not
    resell the barrels containing solids, he charged more for solid waste
    (one dollar per barrel) than he did for liquid waste (50 cents per
    barrel). Davis therefore had a financial incentive to classify drums
    of waste as solid rather than liquid. Davis also testified that he
    considered anything "solid" that did not pour easily, including any
    sludge or residue left in the drums. Also, there is no evidence that
    Davis examined each barrel before classifying a shipment.
    - 54 -
    Finally, Gar notes that while the evidence shows that CWR
    driver Johnny Granfield made the June 21 delivery to the Davis site,
    there is no evidence concerning which CWR driver picked up Gar's waste
    on June 20. This matters because each CWR driver only drove waste to
    the Davis site that he himself collected. Thus Gar argues that the
    possibility that Wilbert Jones, the other CWR driver, picked up its
    waste on June 20 lessens the likelihood that its waste was among the 60
    drums delivered to the Davis site on June 21. However, since there is
    no evidence to show that Granfield was not the driver who collected
    Gar's waste on June 20, and since the evidence did establish that the
    driver who delivered waste to the Davis site had picked it up, the
    district court could have inferred that Granfield collected the waste
    from Gar, and that this waste was on his truck when he made the June 21
    delivery to Davis.
    d. Perkin-Elmer
    PE operated four Connecticut facilities in 1977, at which it
    generated waste that included methylene chloride, 1,1,1-TCA, and
    toluene.29    PE acknowledges that these hazardous substances were
    identified at the Davis site.
    29 PE operated facilities at four locations: (1) a primary
    manufacturing facility in Norwalk; (2) a research facility at 50
    Danbury Road in Wilton; (3) a manufacturing and research facility at 77
    Danbury Road in Wilton; and (4) and Qualitron Corporation's
    manufacturing facility in Danbury. Qualitron became a wholly-owned
    subsidiary of PE in May 1984. PE does not contest its responsibility
    for Qualitron's environmental liability in this case.
    - 55 -
    PE's records show that CWR picked up waste from one of PE's
    facilities seven times during the spring and early summer of 1977: on
    May 26, June 20, June 22 (from three facilities), June 27, and July 1.
    Davis slips indicated that CWR delivered drums to the site on May 27,
    June 21, June 23, June 29, and July 5, 6, and 7. Based on the theory
    that CWR delivered waste within three days of collecting it, the
    district court inferred that the PE pickup on May 26 was dumped at the
    Davis site on May 27; the pickup on June 20 was dumped on June 21; the
    pickups on June 22 were dumped on June 23; the pickup on June 27 was
    dumped on June 29; and the pickup on July 1 was dumped on July 5, 6, or
    7.
    PE objects to the district court's finding of liability on
    numerous grounds.    First, it argues that the court erred in not
    "locating and identifying" PE's waste at the Davis site. As PE notes,
    the district court said in articulating the proof required by CERCLA:
    "In the context of this case, proof that a defendant generator's
    hazardous waste 'can be located and identified at the Davis Site' is a
    sina qua non in establishing arranger liability." Davis IV, 
    31 F. Supp. 2d at 61
     (quoting Davis I, 
    882 F. Supp. at 1221
    ). PE argues
    unpersuasively that the district court intended with this language to
    create a new and higher standard of liability under CERCLA, requiring
    that UTC establish waste deposits with direct evidence such as
    containers bearing PE's name and containing residue of a hazardous
    - 56 -
    waste PE generated. We have already rejected an interpretation of
    CERCLA that "would cast the plaintiff in the impossible role of tracing
    chemical waste to particular sources in particular amounts, a task that
    is often technologically infeasible due to the fluctuating quantity and
    varied nature of the pollution at a site over the course of many
    years."   Acushnet, 
    191 F.3d at 76
    .
    PE also points out that the number of drums of waste picked
    up by CWR in any three-day period before PE's waste was allegedly
    delivered to the Davis site is not the same as the number of drums
    noted on the Davis slip for that day. However, as we have discussed
    above, some of those drums from other customers contained waste oil
    which CWR often salvaged and so likely would not have delivered to the
    Davis site. Thus, the discrepancy between the number of barrels picked
    up and delivered by CWR does not undermine the court's conclusion that
    PE's waste went to the Davis site.
    PE also argues that its waste was not dumped at the Davis
    site because it produced only liquid waste, and all of the Davis slips
    linking its waste to the site indicated that the barrels dumped by CWR
    contained solid waste. PE's contention that it only produced liquid
    waste is contradicted by evidence in the record. Joseph Rabideau,
    designated by PE to testify on behalf of the corporation, testified
    that CWR disposed of waste for PE that included "a solidified scrape
    off type material" and that waste picked up by CWR in open-top five
    - 57 -
    gallon pails was "solidified material." Rabideau also explained that
    PE's use of methylene chloride as a solvent produced "still bottoms"
    that were disposed of "in a fairly solidified form." PE also produced
    a semi-solid paint residue sludge as part of its paint operation.
    Moreover, as we have discussed, Davis's testimony at trial
    demonstrated that his classification of waste as solid or liquid was
    not an exact process. Thus, the district court did not clearly err in
    concluding that waste classified as a liquid by PE might nonetheless be
    considered a solid by Davis if the barrel contained any residue that
    could not be easily poured. Based on this evidence, it was not clear
    error for the district court to conclude that Davis could have
    characterized a shipment of 79 barrels as "solid" even though some --
    or even most -- of the drums he did not examine actually contained
    liquids.
    In sum, all of PE's objections to the district court's
    finding of liability are essentially disputes about the court's finding
    of the facts and the inferences drawn from CWR's established waste
    practices. We must uphold these findings and inferences unless they
    are clearly erroneous. See Dedham, 
    972 F.2d at 457
    . For the reasons
    we have explained, evidence in the record amply supports the district
    court's determinations.
    2. Wilbert Jones's Testimony
    Acco, Ashland, Gar, and Perkin-Elmer all argue that the
    - 58 -
    district court erred in admitting and crediting the deposition
    testimony of Wilbert Jones, one of the two drivers who hauled waste for
    CWR. At the time of his deposition in June 1996, Jones was unemployed
    and very ill. He died in May 1997. UTC paid Jones approximately $30
    per hour as compensation for the time he spent preparing and
    testifying, for a total of between $700 and $800.30
    At trial, the defendants argued that UTC's payments to Jones
    raise an inference that Jones's testimony was improperly influenced by
    UTC and should be excluded for that reason.       The district court
    rejected this argument in a ruling from the bench, finding that "under
    these circumstances it's a reasonable amount to have paid him." The
    defendants appeal this ruling to admit the testimony.
    Citing two grounds for disbelieving Jones's testimony, the
    defendants argue further that the district court should not have
    credited Jones's testimony. First, they state that the payments UTC
    made to Jones -- if they do not render his testimony inadmissible --
    should have caused the district court to reject his account of CWR's
    practices. Second, the defendants argue that Jones should not be
    believed because he signed affidavits prepared for other litigation
    that they claim are inconsistent with his testimony in this case.
    30The defendants claim that UTC did not timely or adequately
    disclose the details of the payments it made to Jones. However, the
    issue of his compensation was raised during the June 1996 deposition
    and the defendants had the opportunity to cross-examine Jones on the
    issue of compensation at that time.
    - 59 -
    a. Grounds for Exclusion
    We first consider whether the district court abused its
    discretion in admitting Jones's deposition testimony.31 To the extent
    that the defendants argue that the payments to Jones rendered him
    incompetent as a witness, their effort fails. Federal Rule of Evidence
    601 provides: "Every person is competent to be a witness except as
    otherwise provided in these rules."32 See also United States v. Devin,
    
    918 F.2d 280
    , 292 (1st Cir. 1990) ("It is a well-established principle,
    embodied in Fed. R. Evid. 601, that witnesses are presumed competent to
    testify."). A district court's determination to allow a witness to
    testify is overturned only for abuse of discretion. See Devin, 
    918 F.2d at 292
    ; United States v. Hyson, 
    721 F.2d 856
    , 864 (1st Cir. 1983)
    31The defendants cite Rule 3.4(b) of the Rhode Island Rules of
    Professional Conduct for the proposition that a lawyer shall not "offer
    an inducement to a witness that is prohibited by law." This ethical
    rule does not advance their argument. The rule only prohibits
    compensation given to a witness in violation of law. For reasons we
    explain here, reasonable compensation to witnesses is not prohibited by
    law and does not render their testimony inadmissible.
    32 As the district court recognized, the defendants' challenge to
    Jones's competency is not a challenge to his competency "in the sense
    of whether he had all of his [mental] faculties." While "competency"
    generally refers to a witness's mental capacity to perceive events and
    comprehend the obligation to tell the truth, see, e.g., United States
    v. Devin, 
    918 F.2d 280
    , 292 (1st Cir. 1990) (affirming district court's
    determination that a witness with a history of psychiatric episodes was
    competent), the concept of competency has been used to challenge
    testimony where it is alleged that a witness's credibility is so poor
    as to render his or her testimony inadmissible, see, e.g., United
    States v. Bedonie, 
    913 F.2d 782
    , 799 (10th Cir. 1990) (rejecting the
    argument that prior inconsistent statements rendered a witness
    incompetent to testify under Rule 601).
    - 60 -
    ("The competency of a witness to testify is for the trial judge.").
    We have been reluctant to exclude testimony based only on the
    fact that a witness was paid. For example, in United States v. Cresta,
    where an informant had been paid by the government, we said: "Rather
    than adopting an exclusionary rule for a particular factual situation,
    irrespective of the mode of payment, we prefer the rule that would
    leave the entire matter to the jury to consider in weighing the
    credibility of the witness-informant." 
    825 F.2d 538
    , 547 (1st Cir.
    1987) (quoting United States v. Grimes, 
    438 F.2d 391
    , 396 (6th Cir.
    1971)). See also Borges v. Our Lady of the Sea Corp., 
    935 F.2d 436
    ,
    440 (1st Cir. 1991) (assuming without deciding that even if a witness's
    statements were obtained improperly, "such impropriety in the means of
    obtaining a statement would not automatically bar admission of the
    statement at trial."). Since the witness in Cresta had received most
    of his compensation prior to trial, his payment was not contingent upon
    the conviction of any of the defendants. See 
    id.
     Because the witness
    had been thoroughly cross-examined about the nature of his agreement
    with the government and the jury had been told to consider his
    testimony with care, the admission of the testimony was upheld on
    appeal.   While Cresta involved a payment to a government informer
    rather than to a witness deposed in a civil action, the reasoning of
    Cresta applies here. The defendants have not claimed that the payment
    to Jones was contingent upon a finding that the defendants were liable.
    - 61 -
    Additionally, the district court was fully informed about the payments
    made to Jones -- as the jury was in Cresta -- and considered those
    payments as part of its assessment of Jones's credibility.           The
    defendants have not attempted to distinguish Cresta from the instant
    matter.33
    b. Grounds for Disbelieving
    The defendants argue that even if the payments Jones received
    did not render his testimony inadmissible, those payments should have
    caused    the   district   court   to   discredit   Jones's   testimony.
    Specifically, they say that Jones's total compensation is excessive in
    light of the fact that he was elderly, ill, and unemployed at the time
    of the deposition. They claim that the time spent testifying did not
    divert Jones from any other lucrative pursuits and that payments at a
    rate of $30 per hour constituted a windfall to him and raise an
    inference that the payments were intended to improperly influence his
    testimony. The district court explicitly considered these arguments
    and rejected them. Reviewing the court's decision to credit Jones's
    33 The case cited by the defendants for the proposition that
    payment to a fact witness to testify at depositions violated a state
    ethics rule prohibiting lawyers from offering inducements to witnesses
    is Golden Door Jewelry Creations, Inc. v. Lloyds Underwriters Non-
    Marine Assoc., 
    865 F. Supp. 1516
    , 1526 (S.D. Fla. 1994). Golden Door
    is easily distinguished from the present case because the payments to
    two witnesses totaled over $400,000 and $100,000. See 
    id.
     Indeed,
    Golden Door itself acknowledges that "[p]ayments made to fact witnesses
    as actual expenses as permitted by law will not be disturbed or set
    aside." 
    Id.
     at 1526 n.11.
    - 62 -
    testimony for clear error, see United States v. Rostoff, 
    164 F.3d 63
    ,
    71 (1st Cir. 1999), we find none.34      Although Jones was ill and
    unemployed when he gave his testimony, $30 per hour is not a payment so
    outrageously high as to raise an inference that his testimony was
    influenced. As the district court stated from the bench when it ruled
    on this issue: "Everybody's time is worth something."
    The defendants also argue that the district court should have
    discredited Jones's deposition testimony because he allegedly made
    prior inconsistent statements in affidavits he signed for litigation
    known as the Picillo Superfund case. See generally O'Neil v. Picillo,
    
    883 F.2d 176
     (1st Cir. 1989). Jones signed these Picillo affidavits in
    September 1995. Four of the affidavits were admitted into evidence at
    the Davis trial. The affidavits all said in similar language that
    Jones dumped waste at the site known as the "Picillo Pig Farm" in
    Coventry, Rhode Island during 1977.      For example, the affidavit
    relating to PE states the following:
    One of the Musillo customers I went to was Perkin
    Elmer in Norwalk, Connecticut. Each week, during
    34The defendants attempt to avoid this deferential standard of
    review by arguing that the district court was not in a position to
    evaluate Jones's credibility firsthand because Jones's testimony at
    trial was submitted by reading lengthy excerpts from his deposition.
    However, it is well-settled that the court's credibility findings
    regarding deposition testimony are still entitled to deference on
    appeal. See Amer. Foreign Ins. Ass'n v. Seatrain Lines of Puerto Rico,
    Inc., 
    689 F.2d 295
    , 298 (1st Cir. 1982) (applying clearly erroneous
    standard of review to factual findings of the trial court even where
    the record consisted only of photographs and deposition testimony).
    - 63 -
    the year 1977, I would haul 15 to 20 drums, 55
    gallon size . . . . I would haul these same drums
    of waste to the Chemical Waste Removal yard in
    Bridgeport where they were stored until a full
    flatbed trailer load of 79 drums was accumulated.
    I would then dispose of these Perkin Elmer drums
    of waste at Picillo Pig Farm.
    Attorneys for the defendants questioned Jones about these statements
    during his deposition and asked him to reconcile the affidavits with
    his testimony in the Davis litigation. He explained that he never
    dumped at the Davis site again after he began dumping at the Picillo
    site in 1977. Therefore, Jones's deposition testimony in this case and
    the Picillo affidavits may be interpreted to provide a consistent
    account of his dumping practices during 1977: Jones dumped at the Davis
    site until Davis stopped accepting waste in September, at which time he
    began dumping at the Picillo pig farm. Moreover, even without this
    explanation, the affidavits are not facially inconsistent with Jones's
    testimony because the affidavits do not mention the Davis site at all,
    leaving open the possibility that Jones dumped at both sites during
    1977, but at different times. In sum, the statements in the Picillo
    affidavits are not, as the defendants contend, flatly contradictory or
    inconsistent with Jones's testimony in the Davis litigation.
    Particularly in light of the documentary evidence offered at trial --
    consisting of Davis slips, bills of lading, and other ledgers and
    receipts -- and the testimony of the Musillo brothers that corroborated
    much of what Jones said, we cannot conclude that the district court
    - 64 -
    clearly erred in choosing to credit some of Jones's testimony.
    3. Exclusion of Master Chart
    Acco and Gar argue that the district court erred in excluding
    a 120-page chart captioned "Contentions of the Contribution Plaintiffs"
    that UTC's lawyers prepared for the Rule 30(b)(6)35 testimony of UTC's
    corporate designee, Troy Charlton. The chart summarized information
    UTC obtained during discovery about the claims and theories of various
    parties to the litigation, most of whom were third or fourth-party
    defendants. More specifically, the chart, organized by party name,
    listed information about the dates of disposal at the Davis site, the
    volume of waste, the hauler used by that party, and the hazardous
    substances contained in the waste. The chart also identified pertinent
    documents and testimony for each of the parties. Charlton referred to
    the chart to answer questions throughout his deposition and
    occasionally read from it verbatim.
    35 Fed. R. Civ. P. 30(b)(6) provides:
    A party may in the party's notice and in a subpoena name as
    the deponent a public or private corporation or a
    partnership or association or governmental agency and
    describe with reasonable particularity the matters on which
    examination is requested. In that event, the organization so
    named shall designate one or more officers, directors, or
    managing agents, or other persons who consent to testify on
    its behalf, and may set forth, for each person designated,
    the matters on which the person will testify. A subpoena
    shall advise a non-party organization of its duty to make
    such a designation. The persons so designated shall testify
    as to matters known or reasonably available to the
    organization.
    - 65 -
    a. Procedural Posture
    UTC claims that Acco and Gar cannot appeal the exclusion of
    the chart from evidence because they did not move for its admission
    below. Only Sealed Air Corporation (SAC) and Morton moved to introduce
    the chart at trial, arguing that it constituted an admission by UTC.
    See Fed. R. Evid. 801(d)(2) (defining admissions by a party-opponent as
    "not hearsay"). Neither SAC nor Morton appealed the district court's
    denial of their motions, although Acco and Gar now argue that the
    district court erred in excluding the chart. Acco and Gar are not
    precluded from making this claim despite their failure to do so below.
    The plain language of Fed. R. Evid. 103(a)(2), written in the passive
    tense, does not require a party to have made an offer of proof at trial
    in order to preserve the right to appeal. Rather, Rule 103(a)(2)
    states that an offer of proof is adequate when: "In case the ruling is
    one excluding evidence, the substance of the evidence was made known to
    the court by offer or was apparent from the context within which
    questions were asked." Fed. R. Evid. R. 103(a)(2) (emphasis added).
    In considering whether an adequate offer of proof was made at trial, we
    have focused on whether the proof sufficed to notify the court of the
    significance of the evidence such that the record was developed
    adequately for appeal. See, e.g., Harrison v. Sears, Roebuck & Co.,
    
    981 F.2d 25
    , 30 (1st Cir. 1992) (Rule 103(a)(2) requires an offer of
    proof "to ensure that the trial judge and the appellate court can
    - 66 -
    evaluate the matter fully"). Morton and SAC made an adequate offer of
    proof in attempting to admit the master chart into evidence. They
    filed motions to admit the chart, as well as lengthy memoranda of law,
    and argued orally before the district court that it was admissible as
    an admission by UTC. Accordingly, Acco and Gar may appeal the district
    court's decision to exclude the chart.36
    b. Admissibility of the Chart
    In moving to introduce the chart at trial, SAC and Morton
    argued that it constituted a party admission by UTC. See Fed. R. Evid.
    801(d)(2). Ruling on this motion from the bench, the district court
    concluded that the chart was UTC's statement but found that it did not
    qualify as an admission. Noting that there must be "some indication of
    reliability" for the statement to be an admission, the court found that
    a party cannot be "bound by statements that simply relate to hearsay
    information received regarding matters clearly outside the scope of the
    corporations knowledge or statements that describe evidence compiled
    from third-party sources by the corporation in preparation for trial."
    The district court then explained its view of the statements contained
    in the master chart, noting first that it appeared "to contain a
    36 UTC cites only one case to support its argument that Acco and
    Gar may not appeal the ruling to exclude the chart. See United States
    v. Long, 
    706 F.2d 1044
    , 1052 (9th Cir. 1983) (finding that defendant
    who did not move to admit an affidavit at trial had waived his right to
    do so on appeal, although his co-defendant had moved for its
    admission). In light of the plain language of Fed. R. Evid. 103 and
    our precedent on this issue, we do not find Long persuasive.
    - 67 -
    mixture of different things."      The court described the chart as
    follows:
    Information that UTC received from a variety of
    third-party sources. For example, it consisted
    primarily of things like what UTC has summarized
    as being contained in documents obtained from Mr.
    Davis and others; what Mr. Carracino and others
    may have said according to UTC in their
    depositions. They all - they also contain, in
    addition to this . . . information, which seems
    to be dominant, they also contain a significant -
    significant number of unattributed statements
    [or] inferences based on the first category of
    information.
    Accordingly, the district court denied Morton and SAC's motions to
    admit the master chart, concluding: "it is impossible to determine
    exactly what all this information is and in a sense it clearly appears
    that most of it is simply information obtained from third-party sources
    and compiled in preparation for trial."
    "[A] trial court enjoys considerable discretion in connection
    with the admission or exclusion of evidence." Udemba v. Nicoli, 
    237 F.3d 8
    , 15 (1st Cir. 2001). The decision not to admit the chart in
    this case is reviewed for abuse of discretion. See Udemba, 
    237 F.3d at 15
    ; Williams v. Drake, 
    146 F.3d 44
    , 47 (1st Cir. 1998). With respect
    to party admissions, we have noted the following:
    For a statement to be an admission under Rule
    801(d)(2), the statement must be made by a party,
    or by a party's agent or servant within the scope
    of the agency of employment. . . . Each link in
    the chain must be admissible, either because it
    is an admission and thus not hearsay or under
    some other hearsay exception. . . . While there
    - 68 -
    may be controversy over whether admissions must
    be based on personal knowledge, . . .
    unattributed statements repeated by party-
    opponents cannot be admissible. As the original
    declarant is unknown, it is impossible to
    determine whether the original declarant also
    fits within the party-opponent definition, and
    thus the exclusion of [the challenged statements]
    was proper.
    Vazquez v. Lopez-Rosario, 
    134 F.3d 28
    , 34 (1st Cir. 1998) (emphasis
    added). Acco and Gar must establish that the chart prepared by UTC is
    grounded in admissible evidence.37 They have not done so. The chart
    was prepared by UTC's lawyers and contained information UTC had
    developed from discovery, including inferences from third-party
    information.   The chart also contained a number of unattributed
    statements. Acco and Gar have not attempted to identify the source of
    these statements or specify which of the statements might be
    admissible. Accordingly, we affirm the district court's decision to
    exclude the chart from evidence.
    4. Proof that Defendants' Waste Caused or Contributed to
    Cleanup Costs
    37Summary charts offered pursuant to Fed. R. Evid. 1006, governing
    charts summarizing voluminous writings, must also be grounded in
    admissible evidence. See United States v. Nivica, 
    887 F.2d 1110
    , 1126
    (1st Cir. 1989); United States v. Sorrentino, 
    726 F.2d 876
    , 884 (1st
    Cir. 1984) ("[P]urported summaries containing assertions not otherwise
    supported by the record are not admissible."). While Acco and Gar have
    not identified the master chart as a summary chart under Rule 1006,
    seeking to admit it as an admission of UTC instead, the master chart --
    more than 100 pages long -- summarizes a large quantity of information,
    and whether it is deemed a party admission or a summary chart, Acco and
    Gar must prove that the statements in the chart are admissible.
    - 69 -
    Ashland and Acco argue that there is no evidence
    concerning the quality or quantity of hazardous substances in the
    Ashland and Acco drums found at the Davis site, and thus no evidence
    that disposal of the drums can cause UTC to incur cleanup costs. Gar
    makes two additional lack of causation arguments, contending that: (1)
    there is no evidence that the company contributed more than background
    levels of contamination since it was found liable for only five drums
    of waste; and (2) that its waste, which contained metals, has not
    contributed to UTC's soil remediation costs because the remediation is
    directed only at cleaning up volatile organic compounds. We review for
    clear error the court's factual finding that the appellants' waste
    triggered cleanup costs.     See Dedham Water, 
    972 F.2d at 457
    .
    In discussing the environmental damage at the Davis site, the
    district court found that three categories of waste were present in the
    soil and ground or surface water at greater than background levels:38
    "volatile organic compounds (VOCs), semi-volatile organic compounds
    (SVOCs), and metals." See Davis IV, 
    31 F. Supp. 2d at 51
    . The VOCs
    included "benzene, methyl ethyl ketone (MEK), methylene chloride,
    perchloroethylene    a/k/a    tetrachloroethylene     (PCE),    1,1,1,
    tricloroethane (1,1,1-TCA), trichlorethylene (TCE), toluene, and
    38The background level of a hazardous substance is measured in
    parts per million or parts per billion, and reflects the level that
    presents an acceptable degree of health risk, according to scientific
    judgments.
    - 70 -
    xylene." 
    Id.
     The metals included "cadmium, copper, cyanide, and
    nickel."   
    Id.
    The court found that Acco, which manufactured controls for
    oil and gasoline lines, produced waste containing 1,1,1,-TCA, cadmium,
    copper, and nickel compounds, cyanide, and hydrochloric or sulfuric
    acid. See 
    id. at 55
    . Ashland, a chemical manufacturer, generated
    waste that contained nitrating acid, composed of sulfuric acid and
    nitric acid, as well as solvents composed of isopropyl alcohol, methyl
    alcohol, toluene, benzene, and xylene. See 
    id. at 56
    . Gar, which "was
    in the electroplating business," generated wastes containing nitric
    acid, copper, nickel, and cyanide.        
    Id.
    The court found that "[s]ince the hazardous waste deposited
    at the Davis site has been commingled into an essentially homogeneous
    'witches' brew,' it is impossible to allocate discrete portions of the
    cleanup cost to any particular type of waste or any particular party."
    
    Id. at 64
    . As a result, the court made a general finding that "the
    evidence does establish hazardous substances produced by Acco-Bristol,
    Ashland, Gar, and Perkin-Elmer as well as Morton were deposited at the
    Davis Site, that each of them contracted for the disposal and that the
    release and threatened release of those kinds of substances triggered
    response costs."    
    Id. at 62
    .
    In finding that the appellants' waste contributed to UTC's
    cleanup costs, the district court drew a reasonable inference based on
    - 71 -
    the evidence. Evidence about the defendants' manufacturing processes
    in 1976 and 1977 supports the finding that each defendant generated
    waste that contained one or more of the hazardous substances identified
    at the Davis site at concentrations exceeding background levels. See
    
    id. at 51
    . Evidence about the commingling of these substances in the
    water and soil at the site supports the finding that the harm caused by
    each individual substance could not be remediated separately. The court
    thus concluded that the defendants had caused or contributed to cleanup
    costs at the site.
    The appellants' arguments to the contrary rely on a highly
    selective reading of Acushnet Co. v. Mohasco Corp., 
    191 F.3d 69
     (1st
    Cir. 1999).       The passage they cite states:
    It might, of course, make sense to say that a
    defendant's release did not 'cause' the
    incurrence of response costs when the monies were
    expended for purposes wholly unrelated to
    responding to environmental contamination. And
    we suppose it may even be accurate to say that a
    generator or transporter of waste did not cause
    a plaintiff to incur remediation costs when that
    person did not actually cause any alleged
    contamination, or perhaps even where clean up
    efforts were directed at cleaning up toxins other
    than those attributed to the defendant.
    Acushnet, 
    191 F.3d at
    77 n.7 (citation omitted).        Based on this
    language, the appellants assert that CERCLA contribution plaintiffs
    must prove that a defendant's waste contributed more than background
    contamination levels and is the type of waste being cleaned up at the
    - 72 -
    site.   Their attempt to somehow raise the threshold for proving
    causation, however, misconstrues the holding of Acushnet.
    In Acushnet, a settling defendant brought a contribution
    action against a non-settler. The non-settler admitted that it had
    discarded waste containing a substance called PAH at the site in
    question, but moved for summary judgment on the ground that the
    quantity of PAH it disposed was far less than the background level and
    tiny in comparison to the amount of PAH dumped by other parties. The
    district court granted summary judgment because the plaintiff failed to
    create a triable issue of fact about whether the defendant's disposal
    of PAH caused cleanup costs to be incurred. We affirmed "on somewhat
    different grounds," saying that "[t]o the extent that the court's
    ruling may be interpreted to incorporate into CERCLA a causation
    standard that would require a polluter's waste to meet a minimum
    quantitative threshold, we disagree."       
    Id. at 72
    .    We explained:
    To read a quantitative threshold into the
    language 'causes the incurrence of response
    costs' would cast the plaintiff in the impossible
    role of tracing chemical waste to particular
    sources in particular amounts, a task that is
    often technologically infeasible due to the
    fluctuating quantity and varied nature of the
    pollution at a site over the course of many
    years.     Moreover, it would be extremely
    difficult, if not impossible, to articulate a
    workable numerical threshold in defining
    causation. . . . Our own decisions provide no
    basis for such an approach. . . . [W]e have never
    discussed CERCLA causation in quantitative terms.
    
    Id. at 76-77
    .
    - 73 -
    To be sure, CERCLA allows a defendant to assert a defense
    that the liability attributable to it is divisible from that borne by
    other parties.    See 
    id. at 77
     ("[W]here environmental harms are
    divisible, a defendant may be held responsible only for his
    proportional share of the response costs").        However, once the
    plaintiff has established that a defendant disposed of hazardous waste,
    Acushnet put the burden of proof on the defendant to show that this
    waste did not contribute to cleanup costs. See 
    id.
     Other courts faced
    with the commingling of chemicals that inevitably occurs at many
    hazardous waste sites have followed a similar approach. See Tosco
    Corp. v. Koch Indus., Inc., 
    216 F.3d 886
    , 891 (10th Cir. 2000) ("The
    plaintiff in a CERCLA response cost recovery action involving multiple
    potentially responsible persons need not prove a specific causal link
    between costs incurred and an individual responsible person's waste.");
    Control Data Corp. v. S.C.S.C. Corp., 
    53 F.3d 930
    , 936 (8th Cir. 1995)
    ("[A] plain reading of [CERCLA] leads us to the conclusion that once a
    party is liable, it is liable for its share, as determined by Section
    9613(f), of 'any' and all response costs, not just those costs 'caused'
    by its release."); United States v. Alcan Aluminum Corp., 
    964 F.2d 252
    ,
    264-66 (3d Cir. 1992); Amoco Oil Co. v. Borden, Inc., 
    889 F.2d 664
    , 670
    n.8 (5th Cir. 1989) ("[I]n cases involving multiple sources of
    contamination, a plaintiff need not prove a specific causal link
    between costs incurred and an individual generator's waste.").
    - 74 -
    Neither Acco nor Ashland have any evidence to show that the
    many hazardous substances contained in their waste "constitute[] no
    more than background amounts of such substances in the environment and
    cannot concentrate with other wastes to produce higher amounts."
    Acushnet, 
    191 F.3d at 77
    . Gar also has no evidence to show that the
    copper, cadmium, and cyanide it generated are present below background
    levels.
    Acushnet also disposes of Gar's additional arguments that its
    waste has not contributed to UTC's cleanup costs. Gar's contention
    that its five drums of waste were insufficient to contribute more than
    background levels of waste presupposes a minimum quantitative threshold
    for liability, which Acushnet rejected. See 
    id. at 77
    .39 Gar also
    argues that it should not have to pay for a cleanup directed at VOCs
    when its waste contained only metals. The record shows that while the
    EPA plan for the Davis site, which drives UTC's cleanup efforts,
    focuses primarily on VOCs, it also aims to mitigate the other
    pollutants present at the site. According to testimony at trial, UTC
    will have to take additional steps to reduce metal contaminants if
    those contaminants are still present in the soil at greater than
    39 The district court took Gar's relatively minor waste
    contribution into account by allocating to the company only .03 percent
    of UTC's cleanup costs. Gar itself calls this allocation "minuscule."
    At oral argument, it became apparent that the real concern of Gar and
    the other appellants is that the government will use the judgment
    against them here in a future § 9607 action for the costs of the
    groundwater and well remedies which have not yet been recovered.
    - 75 -
    background levels after VOC levels have abated. Gar thus has failed to
    show that the harm caused by its waste is divisible from the harm
    treated in UTC's soil remediation.
    5. The Entry of a Declaratory Judgment under § 9613(g)(2) and
    the Declaratory Judgment Act
    The appellants argue that the district court's entry of a
    declaratory judgment was improper because: (1) CERCLA does not provide
    for declaratory relief in a contribution action for future cleanup
    costs; and (2) the Declaratory Judgment Act does not provide for
    declaratory relief in this case because no case or controversy existed
    between the parties. To support the latter claim, the appellants argue
    that UTC failed to prove that it was likely to incur more than its fair
    share of future cleanup costs and that UTC's settlement with the
    government did not extinguish the appellants' liability.40 We discuss
    each argument in turn.
    The appellants argue that CERCLA's declaratory relief
    provision, § 9613(g)(2), does not permit UTC to receive declaratory
    40The appellants also argue that UTC failed to request declaratory
    relief. This argument is easily disposed of. As the district court
    pointed out, UTC need not have used the magic word "declaratory
    judgment" in its pleading to put the defendants on notice that its
    claims could be resolved with a grant of declaratory relief. See Davis
    IV, 
    31 F. Supp. 2d at 60
    . UTC's complaint asked the court to enter a
    judgment to "determine . . . the equitable contribution share of
    liability . . . properly allocated to each [party.]" The court's case
    management order before trial used similar language. This language
    gave the defendants sufficient notice that declaratory relief might be
    granted.
    - 76 -
    relief for cleanup costs that it incurred after the close of discovery
    and continues to incur as it completes the soil remediation. They
    correctly point out that the amount that UTC will ultimately pay for
    soil remediation is unknown. While the EPA projected a cost of $14
    million for soil remediation, this estimate is several years old.
    Rather than allowing into evidence more recent figures on the amount of
    ongoing and future cleanup costs, the court relied on the EPA estimates
    for purposes of the Phase III adjudication, saying that the defendants
    could challenge specific expenditures in post-trial proceedings.41
    The district court dismissed UTC's claims for past cleanup
    costs on the ground that the company had not paid for any cleanup
    before the close of discovery.42 See Davis III, 20 F. Supp. 2d at 330.
    The court expressed doubts about whether UTC was entitled to
    declaratory relief for future costs given the ongoing nature of the
    payments and their unknown total amount, but ultimately concluded that
    "the evidence presented is sufficient to enable the Court to make a
    meaningful allocation based upon the facts presently available." Davis
    41The district court "retain[ed] jurisdiction for the purpose of
    revising this allocation if and when additional facts are discovered
    that were not reasonably available to the parties at the time of trial
    and that clearly demonstrate a change in circumstances so significant
    that the allocation would be rendered manifestly inequitable." Davis
    IV, 
    31 F. Supp. 2d at 69
    .
    42 UTC's indemnification claims were dismissed "for the same
    reason" and because the district court determined that UTC "was not
    entitled to indemnification under Rhode Island law." Davis IV, 20 F.
    Supp. 2d at 330.
    - 77 -
    IV, 
    31 F. Supp. 2d at 59
    . The court thus granted declaratory relief
    pursuant to CERCLA, 
    42 U.S.C. § 9613
    (g)(2), and the Declaratory
    Judgment Act, 
    28 U.S.C. § 2201
    .
    To determine whether the court's grant of declaratory relief
    was proper under § 9613(g)(2), we begin with the plain language of the
    statute. See United States v. Rivera, 
    131 F.3d 222
    , 224 (1st Cir.
    1997).   Section 9613(g)(2) provides that "[i]n any such action
    described in this subsection, the court shall enter a declaratory
    judgment on liability for response costs or damages that will be
    binding on any subsequent action or actions to recover further response
    costs or damages."   
    42 U.S.C. § 9613
    (g)(2).     The statute does not
    explicitly provide for declaratory relief for a contribution action for
    future or past response costs.      However, nothing in the statute
    precludes an interpretation that declaratory relief is available in
    both instances. See Boeing Co. v. Cascade Corp., 
    207 F.3d 1177
    , 1191
    (9th Cir. 2000). The statute suggests this interpretation by adopting
    a flexible time line, providing that "[a] person may seek contribution
    . . . during or following any civil action under . . . section 9607(a)
    of this title."    
    42 U.S.C. § 9613
    (f)(1) (emphasis added).       This
    language anticipates that a defendant in a § 9607 cost recovery action
    may initiate a contribution action before its own liability is
    established. Consistent with this scheme, a § 9607 defendant whose
    liability has been established may be awarded declaratory relief before
    - 78 -
    that liability has been fully discharged.
    The district court acknowledged that a few courts have held
    that § 9613(g)(2) applies to actions brought under § 9607, the vehicle
    for an innocent party to recover cleanup costs, and not to actions
    brought under § 9613(f), the vehicle for a non-innocent party to seek
    contribution from other polluters. See Davis IV, 
    31 F. Supp. 2d at
    590
    (citing Reichhold Chems., Inc. v. Textron, Inc., 
    888 F. Supp. 1116
    ,
    1123-24 (N.D. Fla. 1995) and Sun Co. v. Browning-Ferris, Inc., 
    919 F. Supp. 1523
    , 1532 (N.D. Okla. 1996), overruled in part by 
    124 F.3d 1187
    (10th Cir. 1997)). However, the Ninth and Tenth Circuits have taken
    the position, as we do here, that § 9613(g)(2), the declaratory
    judgment provision of CERCLA, applies to § 9613(f) contribution actions
    for both past and future response costs. In Boeing Co. v. Cascade
    Corp., the Ninth Circuit said:
    CERCLA was intended to encourage quick response
    and to place the costs on those responsible.
    Declaratory relief serves these purposes because
    parties, like those in this case, will know their
    share of costs before they are incurred . . . .
    The costs and time involved in relitigating
    issues as complex as these where new costs are
    incurred would be massive and wasteful.
    Declaratory relief allocating future costs is
    therefore consistent with the broader purposes of
    CERCLA.
    
    207 F.3d at 1191
    ; see also Tosco Corp., 
    216 F.3d at 897
     ("[W]here, as
    here, a responsible party chooses to go to trial and future response
    costs are likely to be incurred, but the exact amount remains unknown,
    - 79 -
    a judgment on proportional liability is an appropriate remedy.").43 We
    agree with these rationales. As the district court said, in this case
    "allocation helps to alleviate the hardship that would be visited upon
    the [PRP] seeking contribution if that PRP was, in effect, required to
    finance the entire cleanup operation before getting a determination
    regarding the shares attributable to the other PRP's." Davis IV, 
    31 F. Supp. 2d at 58
    .
    Since we find that § 9613(g)(2) applies to § 9613(f)
    contribution actions for both past and future response costs, we need
    not address in detail the appellants' arguments that the district
    court's entry of a declaratory judgment was improper under the
    Declaratory Judgment Act because there was no case or controversy
    permitting the court to act. We address the arguments only because
    they apply, at least by implication, to the availability of declaratory
    relief under § 9613(g)(2).
    First, the appellants say that there was no controversy
    between the parties, as the Act requires, because UTC did not prove
    that it would pay more than its fair share of cleanup costs. They
    argue that UTC cannot prove that it is likely to pay more than its fair
    43Other courts have also reasoned that declaratory relief furthers
    CERCLA's goals in finding that the entry of such relief is mandatory in
    § 9607 cost recovery actions. See Dent v. Beazer Materials & Servs.,
    Inc., 
    156 F.3d 523
    , 532 (4th Cir. 1998); Kelley v. E.I. DuPont De
    Nemours & Co., 
    17 F.3d 836
    , 844 (6th Cir. 1994) ("The fact that future
    costs are somewhat speculative is no bar to a present declaration of
    liability.") (internal quotation marks omitted).
    - 80 -
    share of cleanup costs because it began incurring those costs only
    shortly before trial and offered no evidence about the amount of those
    costs.
    The Declaratory Judgment Act provides: "In a case of actual
    controversy within its jurisdiction . . . any court of the United
    States, upon the filing of an appropriate pleading, may declare the
    rights and other legal relations of any interested party seeking such
    declaration, whether or not further relief is or could be sought." 
    28 U.S.C. § 2201
    .    Here, the district court observed:
    the premise underlying UTC's request for a
    judgment 'determining . . . the equitable
    contribution share of liability for the site
    properly allocated to each [party]' is that, at
    some time in the future, it is likely that UTC
    will be required to pay more than its fair share
    of the alleged common liability; and, therefore,
    that it will be entitled to contribution from the
    defendants.
    Davis IV, 
    31 F. Supp. 2d at 58
     (alterations in original). For the
    principle that a PRP seeking contribution must prove that it has paid
    more than its fair share, the court relied on United Tech. Corp. v.
    Browning-Ferris Indus., Inc., 
    33 F.3d 96
    , 100 (1st Cir. 1994) (holding
    that CERCLA allows a non-innocent party bringing a § 9613(f) action
    "only to seek recoupment of that portion of his expenditures which
    exceeds his pro rata share of the overall liability--in other words, to
    seek contribution rather than complete indemnity"). The district court
    set UTC's share as 1.54 percent of the total waste at the Davis site
    - 81 -
    based on the volume of its waste established by the evidence. See
    Davis IV, 
    31 F. Supp. 2d at 67
    . The court translated this 1.54 percent
    liability share into $754,600, using an estimate of $55 million for
    total cleanup and enforcement costs. See 
    id. at 69
    . Reasoning that
    UTC was bound by the proposed consent decrees to pay at least $10.35
    million, the court found that UTC had necessarily incurred more than
    its fair share of cleanup costs.44       See 
    id.
    The appellants' argument to the contrary fails for the same
    reasons that led us to reject the argument that the district court had
    no authority to enter a consent decree. UTC's agreement in Consent
    Decree I to make a cash payment and perform the soil remediation
    created a fixed obligation subject only to the court's approval. UTC
    did not have to actually make the payments to which it agreed to show
    that it was liable for more than its fair share of the total costs of
    cleanup. The ongoing nature of the work and the fact that its ultimate
    cost was not known at trial did not affect the district court's ability
    to consider the evidence that other PRPs contributed to the waste in
    the soil, and to determine whether some of UTC's costs should thus be
    allocated to them.
    The appellants also argue that there is no case or
    44The court reached this figure by deducting the amounts that UTC
    can recoup from other PRPs pursuant to the other partial consent
    decrees from the $16.8 million it agreed to pay pursuant to Consent
    Decree I. We note without resolving the issue that the government sets
    UTC's minimum payment at $9.3 million.
    - 82 -
    controversy between the parties because UTC has not extinguished their
    entire liability. As we have discussed, the partial consent decrees do
    not cover an estimated $21.7 million of the government's projected
    response costs. Because the government can still seek to recover those
    costs from them, the appellants argue that "[p]ermitting UTC to recover
    from the defendants under these circumstances would expose the
    defendants to the CERCLA equivalent of 'double jeopardy.'" In support
    of their position, the appellants cite United Techs. Corp., which
    defined the term "contribution" as "a claim by and between jointly and
    severally liable parties for an appropriate division of the payment one
    of them has been compelled to make." 
    33 F.3d at 99
     (internal quotation
    marks omitted).
    The appellants' argument that UTC is not entitled to
    contribution because it has not extinguished the appellants' entire
    liability fails in light of the plain language of § 9613(f):
    A person who has resolved its liability to the
    United States or a State in an administrative or
    judicially approved settlement shall not be
    liable for claims for contribution regarding
    matters addressed in the settlement. . . .
    A person who has resolved its liability to the
    United States or a State for some or all of a
    response action or for some or all of the costs
    of such action in an administrative or judicially
    approved settlement may seek contribution from
    any person who is not party to a settlement
    referred to [above].
    
    42 U.S.C. § 9613
    (f)(2) & (3)(B) (emphasis added). CERCLA clearly
    anticipated that some settlements, like the one in this case, would
    - 83 -
    cover only a portion of the total cleanup costs for a hazardous waste
    site. The statute does not impose a requirement that a contribution
    action plaintiff must settle the entire cost of cleaning up a site
    before it can seek contribution.
    The   appellants'    complaint   that   they   may   bear   a
    disproportionate share of the total liability if the government chooses
    to bring further proceedings against them is part of the risk they
    assumed in choosing not to settle.       As we have said before:
    CERCLA seeks to provide EPA with the necessary
    tools to achieve prompt cleanups. One such tool
    is the ability to foster incentives for timely
    settlements. To this end, 
    42 U.S.C. § 9613
    (f)(2)
    provides that a party who settles with the
    government 'shall not be liable for claims for
    contribution regarding matters addressed in the
    settlement.' Because only the amount of the
    settlement, not the pro rata share attributable
    to the settling party, is subtracted from the
    aggregate liability of the nonsettling parties,
    section 9613(f)(2) envisions that nonsettling
    parties may bear disproportionate liability.
    This paradigm is not a scrivener's accident. It
    was designed to encourage settlements and provide
    PRPs a measure of finality in return for their
    willingness to settle.
    United Techs. Corp., 
    33 F.3d at 102-03
     (citations and internal
    quotation marks omitted); see also Charles George, 
    34 F.3d at 1086
    ("non-settling defendants . . . are potentially liable for the full
    difference between the costs of cleanup and the total amount paid by
    the settling PRPs"). While our precedents on CERCLA consent decrees
    are attentive to the fairness of the settlements for settling versus
    - 84 -
    non-settling PRPs, they do not go so far as to protect PRPs who choose
    not to settle from the consequences of non-settlement imposed by CERCLA
    itself. See Charles George, 
    34 F.3d at 1088
    . In sum, the district
    court's entry of a declaratory judgment was proper.
    6. Morton's Liability
    The district court found Morton International liable for
    hazardous waste dumped by Thiokol Corporation Chemical Division
    (Thiokol) at the Davis site. For purposes of this case, Morton has
    stipulated that it is a successor to Thiokol's liabilities.
    a. Claims of Clearly Erroneous Factual Findings
    Morton's liability, unlike that of other parties whose waste
    was hauled by CWR, depends on the court's findings about the waste
    practices of CCC. Thiokol was one of the approximately 130 companies
    from whom CCC collected waste during 1976 and 1977. Reasoning that
    since CCC made 47 deliveries to Davis, and since "there is no reason to
    believe that CCC handled Thiokol's waste any differently than the waste
    of its other 130 customers," the district court found that Thiokol's
    waste went to the Davis site, and thus found Morton liable as an
    arranger. Davis IV, 
    31 F. Supp. 2d at 55
    . However, because there was
    no evidence regarding the volume of Thiokol's waste transported by CCC,
    or the volume of waste from other customers that CCC transported to the
    Davis site, the court concluded that it was unable to allocate to
    - 85 -
    Morton a share of the cleanup costs.45      See 
    id.
    We begin with the evidence about CCC's practices. CCC was
    located in Elizabeth, New Jersey and was owned and operated by William
    Carracino. Carracino testified that CCC began sending waste to Rhode
    Island in 1977, initially to Sanitary Landfill. Beginning in May, the
    Capuanos began diverting the CCC waste to the Davis site, and the CCC
    drivers proceeded straight there without stopping first at Sanitary
    Landfill.    CCC continued to bring waste to the Davis site until
    September, when Davis refused to accept the waste and seized CCC's
    truck because CCC was overdue in its payments. Based on the 47 trips
    CCC made to the Davis site between May and the first week of July, and
    the volume of waste transported during those weeks, the district court
    estimated that CCC delivered a total of 441,450 gallons of waste to the
    Davis site. Testimony by Carracino and CCC driver John Mayo about
    these trips to Rhode Island was corroborated by toll receipts and petty
    cash vouchers.
    CCC began collecting Thiokol's waste in 1971. This waste,
    generated by three separate plants in New Jersey, averaged
    approximately 22,000 gallons per year.        Much of the waste was
    identified on shipment forms prepared by Thiokol simply as
    45As became clear at oral argument, Morton still appeals because
    of its concern that the government will use the judgment of liability
    in this case to pursue a § 9607 action for the cost of the groundwater
    and well remediation that remains unallocated.
    - 86 -
    "miscellaneous chemical waste." Testimony by a former Thiokol employee
    indicated that Thiokol did not separate its waste. In particular,
    Thiokol did not separate its chlorinated waste until 1979. The waste
    was disposed of primarily in 55-gallon drums, but Thiokol used drums of
    smaller sizes, as well as 5-gallon pails.        The waste contained
    flammable liquids and spent solvents, including methylene chloride,
    methyl ethyl ketone (MEK), and 1,1,1-TCA, all of which were found at
    the Davis site.    Other waste picked up on a more occasional basis
    included urethane, filter cakes used in producing plasticizers, and
    lubricating oil.
    CCC handled waste it collected in a variety of ways. It sold
    some liquid waste to salvagers, burned some of the flammable liquids in
    an incinerator on the Elizabeth site, transported waste to various dump
    sites, and stored some waste on the premises for future disposal.
    Carracino testified that solid waste, polymers, and sludges were sent
    straight from CCC to disposal sites because of their tendency to clog
    the incinerator.      CCC employee John Prahm, who operated the
    incinerator, corroborated that testimony. Waste shipment forms confirm
    that CCC picked up polymers from Thiokol.
    Evidence at trial indicated that CCC's incinerator did not
    effectively destroy many chemicals -- particularly chlorinated waste --
    because it did not operate at a sufficiently high temperature. An
    expert witness testified that the incinerator produced a sludge or
    - 87 -
    residue, which was itself a hazardous waste, because of this
    inefficient operation. Prahm testified that this residue from the
    incinerator was placed in drums for disposal. Evidence regarding
    Thiokol's disposal practices supports an inference that some of its
    flammable waste likely went to the Davis site as residue from the
    incinerator. More specifically, Thiokol did not separate chlorinated
    waste from unchlorinated waste, and chlorinated waste was not
    effectively destroyed in the incinerator because it required a higher
    temperature. Thus, we cannot conclude that the district court erred in
    finding that at least some of Thiokol's waste "consisted of flammable
    solvents that probably were incinerated," Davis IV, F. Supp. 2d at 55,
    and that because there is no basis for finding that Thiokol's waste was
    treated differently from other waste at CCC, the hazardous residue
    produced by the incineration of such waste was likely placed in drums
    and transported to the Davis site.
    Thiokol's disposal of waste in 5-gallon pails further
    supports the district court's finding of liability. UTC offered the
    deposition testimony of a former Thiokol employee, Melvin Schulman,
    that Thiokol disposed of some liquid waste in spring-top, 5-gallon
    cans. Waste shipment forms indicate that CCC picked up these cans for
    disposal. A notation on at least one cancelled check drawn on CCC's
    account reads "5 gal. pails to RI, 6/8/77." Carracino confirmed in his
    deposition testimony that the notation was in his writing and that the
    - 88 -
    check was payment for dumping waste. Davis also testified at trial
    that he recalled receiving loads of waste in which 5-gallon pails,
    containing liquid waste, had been transported to his site on top of 55-
    gallon drums. Davis specifically recalled that these shipments came
    from New Jersey. While the testimony regarding these 5-gallon pails
    does not establish conclusively that Morton's waste was dumped at the
    Davis site, the district court was not clearly erroneous in crediting
    this testimony and considering it part of the evidence tending to
    establish that it was more probable than not that Morton's hazardous
    waste was shipped by CCC to the site.
    Morton argues that "the mere presence of 1,1,1-TCA in
    Morton's waste and its presence at the Davis site does not, without
    more, establish that Morton's waste was located at the Davis site."
    However, the district court did not base its finding that Morton was
    liable solely on the presence of that chemical at the site. Rather,
    the district court inferred from other evidence that Thiokol's waste
    was taken to the Davis site and noted that such an inference "finds
    some support" in the fact that the chemical was found at the site.
    Davis IV, 
    31 F. Supp. 2d at 55
    .
    b. Claims of Legal Error
    Morton argues that the district court improperly shifted the
    burden of proof to Morton, requiring it to show that it had not dumped
    waste at the Davis site, rather than requiring UTC to prove each
    - 89 -
    element of its claim for contribution.       Morton cites New Jersey
    Turnpike Auth. v. PPG Indus., Inc., 
    197 F.3d 96
    , 105 (3d Cir. 1999) for
    the proposition that UTC "must offer some proof that [the defendants]
    deposited, or caused the disposal of, [the waste] at each of the sites
    at issue in this case." Morton seems to construe this requirement of
    "some proof" as a requirement for direct, not circumstantial proof.
    However, for reasons explained above, UTC introduced adequate
    circumstantial evidence that Thiokol deposited waste at the Davis site.
    That circumstantial evidence distinguishes this case from New Jersey
    Turnpike Authority, where the plaintiff introduced no evidence
    regarding the transporters the defendants may have used and relied only
    on "the conceded large scale production of [the waste] by the
    appellees, the need for its local disposal, the proximity of the
    appellees' production facilities to the sites at issue, and the use of
    this material as fill over the years."        
    Id. at 109
    .   Here, UTC
    introduced evidence of Thiokol's production of hazardous waste, CCC's
    records regarding pickups of waste and deliveries to the Davis site,
    and CCC's practices in handling different kinds of waste. We do not
    agree with Morton that the district court engaged in an improper
    burden-shifting analysis in finding, based on this evidence, that some
    of Thiokol's waste was dumped at the Davis site.
    Finally, Morton argues that it was impermissible for the
    district court to find it liable as an arranger because the court
    - 90 -
    declined to allocate to Morton a specific share of responsibility.
    However, Acushnet, 
    191 F.3d 69
    , precludes this argument. Acushnet
    emphasizes the broad discretion of a district court in allocating
    responsibility: "A court, in evaluating contribution claims under §
    9613(f), is 'free to allocate responsibility according to any
    combination of equitable factors it deems appropriate.'" Id. at 78
    (quoting O'Neil v. Picillo, 
    883 F.2d at 183
    ). The district court here
    found that "the fairest, and most practical, measure of relative
    responsibility is the quantity or volume of hazardous waste
    attributable to each party." Davis IV, 
    31 F. Supp. 2d at 64
    . Because
    there was no way to calculate the volume of waste Thiokol dumped at the
    Davis site, the court declined to allocate a share of responsibility to
    Morton. This determination was well within the district court's broad
    discretion.
    Morton argues that the district court's decision not to
    allocate a share of responsibility to Morton should have compelled a
    finding that Morton was not liable because Thiokol's waste could not be
    located and identified at the Davis site.46 However, as we have noted,
    we said in Acushnet that there is no minimum quantity threshold for
    imposing liability on polluters, 
    191 F.3d at 76
    , adding that "[i]n an
    46Morton also claims that the district court erred in finding
    liability without applying a standard of "locating and identifying" its
    waste at the Davis site. We have already rejected an interpretation of
    § 9613(f) that would require an arranger's waste to be specifically
    located at the Davis site with direct evidence.
    - 91 -
    appropriate set of circumstances, a tortfeasor's fair share of the
    response costs may even be zero, id. at 78. The district court's
    decision not to allocate responsibility to Morton is consistent with
    Acushnet, and Morton has not even attempted to explain why the
    principles of that opinion should not apply here.
    7. Successor-in-Interest Liability for Gar
    Black & Decker ("B & D") argues that the district court erred
    in finding that it, rather than Electroformers, Inc., is Gar's
    corporate successor-in-interest and thus liable for Gar's disposal of
    waste at the Davis site. Gar's corporate history is as follows. In
    1977, MITE Corporation owned Gar Electroforming Division, the
    manufacturing facility in Danbury, Connecticut that generated the
    hazardous waste disposed of at the Davis site. In November 1978, MITE
    agreed to sell Gar's assets to Electroformers, Inc., which had
    incorporated a month earlier. The Asset Purchase Agreement signed by
    the parties in January 1979 provided that Electroformers would buy
    certain accounts receivable, furniture, fixtures, machinery, equipment,
    trademarks and trade names, business records, inventory and customer
    lists. Electroformers used the name "Gar Electroformers Division" for
    a time after the sale, subleased the Danbury facility from MITE, and
    continued to make the same product with the same manufacturing process
    and to use the same employee pension plan. MITE agreed not to compete
    with Electroformers in its area of business for ten years. The Asset
    - 92 -
    Purchase Agreement provided that the "[b]uyer will not assume any of
    the liabilities of the Gar Electroforming Division existing on the date
    of the closing and MITE agrees to defend any claims relating thereto
    presented against Buyer and to save Buyer harmless from any such
    claims." MITE also represented that, to its knowledge, it was not in
    violation of any environmental or pollution-related law or ordinance.
    In 1985, the Emhart Corporation bought MITE. In 1989, B & D acquired
    Emhart, which continues to exist as B & D's wholly owned subsidiary.
    UTC sued both B & D and Electroformers for contribution as
    Gar's successor-in-interest. Both defendants filed motions for summary
    judgment.    The district court referred to a magistrate judge the
    question of which entity, B & D or Electroformers, should be liable as
    Gar's successor. The magistrate judge discussed the choice between the
    state law and federal common law tests for determining corporate
    successor liability, and found that B & D was liable under either
    analysis because Electroformers bought Gar's assets from MITE through
    a true assets purchase agreement. The district court adopted this
    recommendation.
    On appeal, B & D argues that the federal common law
    "substantial continuation" test should determine corporate successor
    liability under CERCLA, and that Electroformers should be found liable
    using this test. Electroformers and UTC47 argue that Connecticut's
    47   UTC took the opposite position before the district court.
    - 93 -
    "mere continuation" test should apply,48 and that Electroformers should
    not be found liable using either the "substantial continuation" or the
    "mere continuation" tests. We begin with the choice of law question,
    which we review de novo. See Kukias v. Chandris Lines, Inc., 
    839 F.3d 860
    , 861 (1st Cir. 1988).
    The "mere continuation" test is an exception to the common
    law rule that the buyer of a corporation's assets (as opposed to its
    stock) does not incur liability for the divesting corporation's debts.
    See Ed Peters Jewelry Co. v. C & J Jewelry Co., 
    124 F.3d 252
    , 266 (1st
    Cir. 1997). The test is designed to protect creditors from sales that
    seek to evade valid claims.     See 
    id.
       Successor liability is an
    equitable doctrine, and courts traditionally consider five factors: (1)
    the divesting corporation's transfer of assets; (2) payment by the
    buyer of less than fair market value for the assets; (3) continuation
    by the buyer of the divesting corporation's business; (4) a common
    officer of the buyer and divesting corporations who was instrumental in
    the transfer; and (5) inability of the divesting corporation to pay its
    debts after the assets transfer.      See 
    id. at 268
    .
    The federal "substantial continuation" test, which has been
    adopted in past cases by a few circuits, see B.F. Goodrich v. Betkoski,
    
    99 F.3d 505
    , 519 (2d Cir. 1996); United States v. Carolina Transformer
    48The Asset Purchase Agreement calls for application of
    Connecticut law, and the parties do not argue that another state's law
    should apply.
    - 94 -
    Co., 
    978 F.2d 832
    , 837 (4th Cir. 1992), requires courts to consider
    eight factors: "(1) retention of the same employees [by the buyer]; (2)
    retention of the same supervisory personnel; (3) retention of the same
    production facilities in the same location; (4) production of the same
    product; (5) retention of the same name; (6) continuity of assets; (7)
    continuity of general business operations; and (8) whether the buyer
    holds itself out as a continuation of the" divesting corporation,
    Carolina Transformer Co., 
    978 F.2d at 838
    . In general, before creating
    a federal rule courts must consider whether federal interests require
    a nationally uniform body of law, whether applying state law would
    frustrate or conflict with a specific federal objective, and the extent
    to which a federal rule would disrupt commercial relationships
    predicated on state law. See United States v. Kimbell Foods, Inc., 
    440 U.S. 715
    , 728-29 (1979). In adopting the "substantial continuation"
    test, courts have cited CERCLA's "broad remedial purpose" and the
    "importance of national uniformity." See B.F. Goodrich, 99 F.3d at
    519; Carolina Transformer Co., 
    978 F.2d at 837
    .
    Other courts, however, have rejected the need for a federal
    test. See, e.g., Redwing Carriers, Inc. v. Saraland Apartments, 
    94 F.3d 1489
    , 1501-02 (11th Cir. 1996); City Mgmt. Corp. v. U.S. Chem.
    Co., Inc., 
    43 F.3d 244
    , 253 n.12 (6th Cir. 1994). These cases heed the
    Supreme Court's warnings that courts should presume that matters left
    unaddressed are subject to state law when a "comprehensive and
    - 95 -
    detailed" federal statutory regime is at issue, and that cases in which
    the creation of a "special federal rule would be justified" generally
    are "few and restricted." See O'Melveny & Meyers v. Fed. Deposit Ins.
    Corp., 
    512 U.S. 79
    , 85 & 87 (1994).
    We have concluded that the majority rule is to apply state
    law "so long as it is not hostile to the federal interests animating
    CERCLA," and have applied Massachusetts contracts law to determine an
    issue of successor liability. John S. Boyd Co., Inc. v. Boston Gas
    Co., 
    992 F.2d 401
    , 406 (1st Cir. 1993). Recent Supreme Court precedent
    confirms that Boyd's approach is correct. The Court applied state
    corporation law in a recent CERCLA case involving the potential
    liability of a parent corporation for its subsidiary and left little
    room for the creation of a federal rule of liability under the statute.
    See United States v. Bestfoods, 
    524 U.S. 51
    , 63 (1998) ("CERCLA is . .
    . like many another congressional enactment in giving no indication
    that the entire corpus of state corporation law is to be replaced
    simply because a plaintiff's cause of action is based upon a federal
    statute.") (internal quotation marks omitted). The Court's statements
    in Bestfoods and O'Melveny demonstrate that to justify the creation of
    a federal rule, "there must be a specific, concrete federal policy or
    interest that is compromised by the application of state law."
    Atkison, Topeka & Santa Fe Railway Co. v. Brown & Bryant, Inc., 
    159 F.3d 358
    , 363-64 (9th Cir. 1998) (internal quotation marks omitted).
    - 96 -
    We see no evidence that application of state law to the facts of this
    case would frustrate any federal objective.       Connecticut's "mere
    continuation" test thus is the correct test for determining successor
    liability for the hazardous waste disposed by Gar.
    In applying the "mere continuation" test, the magistrate
    judge recommended successor liability for B & D rather than
    Electroformers   based   on   the   following   facts:   (1)   MITE   and
    Electroformers did not share a common officer or director who was
    involved in the transfer; (2) MITE received fair compensation for Gar;
    (3) MITE continued to operate its other businesses; (4) MITE remained
    financially viable.49 B & D did not challenge these factual findings,
    but objects to the magistrate's conclusion that Electroformers
    purchased Gar's assets through a true asset purchase agreement on the
    grounds that Electroformers shared certain commonalities with Gar and
    essentially continued its business. In support of this position, B &
    D notes that Electroformers made the same product that Gar made when
    MITE owned it, employed the same supervisory employees, used the same
    production facility and the same customer base, and initially operated
    under Gar's name.
    The facts emphasized by B & D do not outweigh those cited by
    the magistrate judge to support the finding that Electroformers merely
    49The magistrate judge also found B & D liable under the federal
    law "substantial continuation" test. Because we apply the state law
    test, we do not reach this issue.
    - 97 -
    bought Gar's assets from MITE. MITE's receipt of fair compensation for
    the Gar division and the lack of common officers and directors between
    the two entities indicate that its sale of Gar's assets to
    Electroformers was an arms-length deal. Moreover, MITE continued as a
    financially viable business following the sale, leaving little reason
    to except it from the rule that successor liability does not transfer
    when one company buys another's assets. See Ricciardello v. J.W. Gant
    & Co., 
    717 F. Supp. 56
    , 59 (D. Conn. 1989) ("A sale of assets by one
    corporation to another, in good faith and for valuable consideration,
    does not impose any liability on the buyer for the debts of another.")
    (citing Davis v. Hemming, 
    127 A. 514
    , 518 (Conn. 1925)). The district
    court did not err in adopting the magistrate judge's recommendation
    imposing successor liability on B & D rather than Electroformers.50
    8. UTC's Appeal
    a. The Judgment in Favor of Macera
    After UTC rested its case, the district court rendered a
    bench decision granting judgment as a matter of law pursuant to Fed. R.
    Civ. P. 52(c) in favor of BFI and Macera. Macera Brothers Container
    50B & D also argues that the magistrate judge's recommendation of
    successor liability for B & D rather than for Electrofomers conflicts
    with the magistrate judge's recommendation of successor liability for
    BFI, the purchaser of Macera. Since the district court did not adopt
    the magistrate judge's recommendation of liability for BFI, any
    disparity between the two recommendations, if there is one, lacks legal
    significance.
    - 98 -
    Service, Inc.51 hauled waste to various facilities for disposal.
    Michael Macera and Robert Cece were two principals in the corporation.
    BFI Waste Systems of North America, Inc. is in this action only as
    successor to Macera.52
    The court explained its reasons for the judgment in a written
    memorandum and order after the trial concluded. See Davis III, 20 F.
    Supp. 2d at 329.53 UTC appeals this ruling on two grounds. First, UTC
    claims that it proved Macera was liable as a transporter under CERCLA.
    Second, UTC argues that it proved Macera was liable as an arranger of
    hazardous waste, and that its claim of liability on this theory was
    timely asserted. Finally, BFI argues that if this Court finds that the
    district court erred in granting the judgment in favor of BFI and
    Macera, BFI is still not liable because it is not Macera's corporate
    successor. For the reasons that follow, we affirm the district court's
    judgment on partial findings in favor of BFI and do not reach BFI's
    51Macera Brothers Container Service, Inc. changed its name to
    Macera Disposal, Inc. in 1984. In 1987, Macera Disposal was merged
    into M & C Enterprises, Inc. BFI purchased the assets of M & C
    Enterprises in July 1987.
    52We will refer collectively to Macera Brothers Container Service,
    Michael Macera, Robert Cece, and BFI as "Macera" when discussing the
    claims regarding transporter and arranger liability.
    53We review for clear error the factual findings made as part of
    the district court's judgment on partial findings. "Findings of fact,
    whether based on oral or documentary evidence, shall not be set aside
    unless clearly erroneous." Fed. R. Civ. P. 52(a) (emphasis added).
    See also Touch v. Master Unit Die Prods., Inc., 
    43 F.3d 754
    , 757 (1st
    Cir. 1995).
    - 99 -
    claim regarding successor liability.
    1. Transporter Liability
    CERCLA imposes transporter liability on "any person who
    accepts or accepted any hazardous substances for transport to disposal
    or treatment facilities, incineration vessels or sites selected by such
    person" from which there is a release of hazardous substances. 
    42 U.S.C. § 9607
    (a)(4) (emphasis added). Noting that the statute itself
    does not define the term "selected," the district court in this case
    stated: "a person 'selecting' a site is a person who chooses that site
    from a group of possible sites." Davis III, 20 F. Supp. 2d at 333.
    Adopting a standard of "[a]ctive and substantial participation," the
    court ruled that "determining whether, or to what extent, a transporter
    made or actively participated in the site selection decision turns on
    the nature of the dealings between the transporter and the generator."
    Davis III, 20 F. Supp. 2d at 333-34. The court found that UTC had
    failed to present sufficient evidence regarding the negotiations
    between Macera and the generators for whom it hauled waste. Moreover,
    because there was evidence that some of the waste hauled by Macera came
    from UTC, the court found that UTC should have presented evidence
    regarding its own dealings with Macera in order to prove that Macera
    actively participated in the selection of the Davis site for UTC's
    waste.   See Davis III, 20 F. Supp. 2d at 334.
    The district court applied the correct legal standard in
    - 100 -
    determining whether Macera is a transporter under CERCLA. See Tippins
    Inc. v. USX Corp., 
    37 F.3d 87
    , 94 (3d Cir. 1994).     In Tippins, the
    court stated:
    [W]e believe that a person is liable as a
    transporter not only if it ultimately selects the
    disposal facility, but also when it actively
    participates in the disposal decision to the
    extent of having had substantial input into which
    facility was ultimately chosen. . . The
    substantiality of the input will be a function,
    in part, of whether the decisionmaker relied upon
    the transporter's special expertise in reaching
    its final decision.
    37 F.3d at 94-95 (citation omitted). See also B.F. Goodrich, 99 F.3d
    at 520; United States v. USX Corp., 
    68 F.3d 811
    , 820 (3d Cir. 1995).
    In contrast to a transporter who actively participated in the selection
    of a site, Tippins described circumstances where a transporter that
    merely followed the orders of a generator would not be liable:
    We emphasize that for liability to attach, a
    transporter must be so involved in the selection
    process that it has substantial input into the
    disposal decision. A transporter clearly does
    not select the disposal site merely by following
    the directions of the party with which it
    contracts. . . . In such cases, the transporter
    is no more than a conduit of the waste and its
    connection with the material is the most
    attenuated among potentially responsible parties.
    . . . Congress intended such transporters to
    avoid liability.
    37 F.3d at 95 (citations and internal quotation marks omitted). See
    also Interstate Power Co. v. Kansas City Power & Light Co., 
    909 F. Supp. 1284
    , 1289 (N.D. Iowa 1994) (granting summary judgment to party
    - 101 -
    alleged to be a transporter where evidence showed the party had no
    discretion in hauling waste to the site but merely followed the orders
    of a waste generator).      Thus,   Tippins distinguishes between
    transporters that actively participate in the selection decision or
    have substantial input in that decision, and transporters that merely
    follow the directives of the generator. UTC has not explained why we
    should not follow the approach in Tippins. Accordingly, we examine the
    facts to determine whether the district court was clearly erroneous in
    concluding that Macera did not actively participate in the decision to
    transport waste to the Davis site.
    The only evidence of Macera's participation in selecting the
    Davis site was the testimony of William Davis regarding his dealings
    with Robert Cece. Davis testified that he had known Cece for a long
    time, and that Cece visited the site on one occasion to discuss the
    possibility of dumping waste there. Davis also stated that he was paid
    by Macera for this dumping. The following excerpt from the district
    court's opinion summarizes its reasoning regarding the inferences that
    could be drawn from this evidence:
    The fact that Cece approached Davis and made
    arrangements to dump at the Site could support a
    reasonable inference that Cece actively and
    substantially participated in the selection of
    the Site. On the other hand, it also would be
    reasonable to infer that Cece was acting at the
    direction of UTC, the generator of the waste.
    Ordinarily, the former inference might be more
    plausible. However, under these circumstances,
    its plausibility is eroded by the dearth of
    - 102 -
    evidence regarding the dealings between the
    Macera defendants and UTC.
    Davis III, 20 F. Supp. 2d at 334. The district court's determination
    on this matter is essentially a refusal to choose between two equally
    plausible inferences where there is no reason to support one inference
    over the other. Because rulings under Rule 52(c) are reviewed for
    clear error, see Fed. R. Civ. P. 52(a), we defer to the district
    court's decision not to draw any inference.
    In an attempt to evade the clear error standard of review for
    factual findings of the district court, UTC claims that the district
    court made an error of law by impermissibly drawing an adverse
    inference regarding UTC's failure to present evidence of its
    negotiations with Macera about the hauling of its waste. UTC quotes
    the following language from the court's written opinion in support of
    this claim:
    Since evidence of the dealings between UTC and
    the Macera defendants was readily available to
    and under the control of UTC, UTC's failure to
    present that evidence or to explain why it was
    unable to do so, gives rise to an inference that
    the evidence would have been unfavorable to UTC.
    . . . In short, the absence of evidence regarding
    the Macera defendants' dealings with UTC and the
    fact that such evidence was within UTC's control
    cause this Court to find that UTC has failed to
    establish that Macera Brothers 'selected' the
    Davis Site.
    Davis III, 20 F. Supp. 2d at 334 (citation omitted). The case cited by
    the district court in support of this inference provides that two
    - 103 -
    conditions must be satisfied before an adverse inference about the non-
    production of evidence may be drawn.      See Commercial Ins. Co. v.
    Gonzalez, 
    512 F.2d 1307
    , 1314 (1st Cir. 1975). The evidence must be
    "specially available" to the non-producing party, and that party must
    have "had some reason to suppose that non-production would justify the
    inference." 
    Id.
     UTC argues that "specially available" means evidence
    within its control but not within the control of Macera. Thus, UTC
    claims that the inference cannot apply in this case because Macera also
    has knowledge of any negotiations between Macera and UTC regarding the
    disposal of UTC's waste. Cf. Kean v. Comm'r of Internal Revenue, 
    469 F.2d 1183
    , 1187 (9th Cir. 1972) ("Where a potential witness is equally
    available to both parties, no inference should be drawn from the
    failure of a party to call such witness.").
    We conclude that UTC, with its reliance on the "adverse
    inference" argument, misses the essential point of the district court's
    analysis. The district court expressed its concern over UTC's overall
    failure to present any evidence whatsoever about Macera's relationship
    with generators -- both UTC and other unidentified parties -- for whom
    it hauled waste. Several paragraphs before discussing the inference
    drawn against UTC, the court stated: "UTC has failed to present
    sufficient evidence regarding those dealings [between Macera and
    generator defendants] to sustain its burden of proving that Macera
    Brothers 'selected' the Davis Site." Davis III, 20 F. Supp. 2d at 334.
    - 104 -
    The district court's conclusion about the insufficiency of the evidence
    at this point in its analysis makes the propriety of the adverse
    inference irrelevant. The court found against UTC simply because UTC
    failed to meet its burden of proof. In light of that finding, any
    adverse inference that might be drawn from UTC's failure to produce
    evidence of its own negotiations with Macera was not necessary to the
    district court's conclusion. We conclude, therefore, that the district
    court did not rely improperly on an adverse inference and affirm its
    finding that UTC did not present sufficient proof that Macera selected
    the Davis site.
    2. Arranger Liability
    UTC also argues that it proved that Macera was liable as an
    arranger of waste under CERCLA. Macera claims that UTC's assertion of
    an arranger claim is untimely. In the 1991 third-party complaint
    originally naming Macera as a defendant, UTC alleged only that Macera
    was liable as a transporter of waste. The district court entered a
    case management and scheduling order in December 1995 providing that
    "[a]ll cross-claims and counterclaims are deemed made and denied,
    except that contractual claims for indemnity must be specifically
    plead."   The order also specified that amendments to third-party
    complaints had to be filed before January 2, 1996.
    After the case was transferred to Chief Judge Torres, he
    entered an order in January 1998 providing:
    - 105 -
    On December 14, 1995, an order was entered
    providing that all parties were deemed to have
    asserted claims, cross-claims and counterclaims
    against all other parties for contribution and/or
    indemnity without the need for specifically
    pleading such claims.
    Whereas it is impossible to determine what
    parties, in fact, are asserting such claims, the
    nature of any such claims or the basis for any
    such claims . . .
    it is hereby ORDERED that on or before February
    15, 1998, each party asserting a claim, cross-
    claim or counterclaim for contribution and/or
    indemnity shall, if such party has not already
    done so, file and serve pleadings setting forth
    such claim. Such pleadings shall specify the
    precise nature and basis of each claim asserted.
    Relying on that order, UTC filed an amended third-party complaint
    against Macera, alleging for the first time that Macera was also liable
    as an arranger. In its answer, Macera objected to this amendment as
    untimely. For reasons that are unclear, the issue of whether UTC
    timely pled an arranger claim against Macera was not resolved before
    trial. However, the district court addressed this dispute during oral
    argument on Macera's Rule 52 motion for judgment after UTC rested its
    case.   When UTC's lawyer first mentioned arranger liability, the
    following exchange occurred:
    THE COURT: Arranger didn't come into this until
    much later. There is nothing about, there is no
    arranger liability theory pled in the original
    complaint against Cece, was there?
    UTC'S COUNSEL: There was no arranger liability
    pled in our original complaint. We did take
    - 106 -
    advantage of Your Honor's invitation to correct
    the pleadings in [January].
    THE COURT: Not correct the pleadings, not to
    correct the pleadings. Make it clear who was
    asserting claims against whom, that was the -
    After additional discussion on the issue, the district court stated:
    And I certainly don't think that the attempt to
    include the arranger theory in the specific
    claims that the Court required parties to assert
    just before the case went to trial, I don't think
    that that invitation or requirement that the
    parties plead their - let the Court know who they
    were asserting claims against constituted a
    license to amend the pleadings and raise new
    theories, and there is no question that arranger
    liability is significantly different from hauler
    liability.
    Thus, the district court ruled that its order of January 1998 did not
    authorize UTC to assert a belated claim of arranger liability. We
    defer to this interpretation because the district court was uniquely
    positioned to explain the meaning of its own pretrial order. See
    Martha's Vineyard Scuba Headquarters, Inc. v. Unidentified, Wrecked &
    Abandoned Steam Vessel, 
    833 F.2d 1059
    , 1066-67 (1st Cir. 1987) ("We
    have noted before the special role played by the writing judge in
    elucidating the meaning and intendment of an order which he
    authored."); Lefkowitz v. Fair, 
    816 F.2d 17
    , 22 (1st Cir. 1987)
    ("[U]ncertainty as to the meaning and intendment of a district court
    order can sometimes best be dispelled by deference to the views of the
    writing judge."). We reject UTC's argument that the order authorized
    it to amend its complaint.
    - 107 -
    Next, UTC argues that the district court erred in denying UTC
    permission to amend its complaint to conform to the evidence offered at
    trial. "When issues not raised by the pleadings are tried by express
    or implied consent of the parties, they shall be treated in all
    respects as if they had been raised in the pleadings." Fed. R. Civ. P.
    15(b). "Such late pleading amendments may be allowed under Rule 15(b)
    at the discretion of the court, but only to the extent that the party
    opposing the amendment will not be unduly prejudiced." Campana v.
    Eller, 
    755 F.2d 212
    , 215 (1st Cir. 1985) (emphasis added). Where the
    party seeking amendment of the pleadings has shown no justification for
    its delay in doing so, we have affirmed the trial court's ruling to
    deny the amendment. See 
    id. at 216
    . UTC has not even attempted to
    explain its failure to amend the pleadings at an earlier date.
    Still, UTC argues that we should reverse the district court's
    determination on this issue because Macera did not suffer prejudice as
    a result of UTC's untimely pleading of the arranger claim. UTC insists
    that "the evidence admitted to prove 'transporter' liability was no
    different than the proof that established 'arranger' liability."
    However, any lack of prejudice to Macera is irrelevant because the
    district court gave other reasons for its ruling.         We consider
    prejudice to the non-moving party as one factor to be weighed in
    permitting an untimely amendment to the pleadings. See, e.g., Campana,
    
    755 F.2d at 215
    . In other words, a finding that the non-moving party
    - 108 -
    would not be prejudiced by an untimely amendment does not compel a
    determination that the amendment is appropriate.
    UTC also argues that Macera consented to being tried as an
    arranger by failing to object to evidence tending to establish arranger
    liability at trial. The district court rejected this claim, citing its
    recollection that Macera had objected to the use of the term
    "arranger." We affirm this determination. "Consent to the trial of an
    issue may be implied if, during the trial, a party acquiesces in the
    introduction of evidence which is relevant only to that issue." DCPB,
    Inc. v. City of Lebanon, 
    957 F.2d 913
    , 917 (1st Cir. 1992) (emphasis
    added).   As just noted, UTC asserted that Macera would not be
    prejudiced by a ruling that it consented to being tried as an arranger
    because the evidence proving Macera's liability as an arranger of
    hazardous substances was the same evidence proving Macera's liability
    as a transporter. This argument about lack of prejudice forecloses
    UTC's claim regarding trial by consent: "The introduction of evidence
    directly relevant to a pleaded issue cannot be the basis for a founded
    claim that the opposing party should have realized that a new issue was
    infiltrating the case." 
    Id.
     Where, as here, the evidence regarding
    Macera's transport of waste to the Davis site was directly relevant to
    transporter liability, and, according to UTC, arranger liability, we
    find no error in the court's conclusion that Macera did not consent to
    being tried on an arranger theory by not objecting to the admission of
    - 109 -
    that evidence.54
    b. The Judgment in Favor of the City of New Jersey
    UTC brought a contribution claim against the City of New
    Jersey (Jersey City) for disposing of approximately 2,000 drums
    abandoned on a city pier and containing corrosive, toxic and flammable
    substances found at the Davis site. The district court found Jersey
    City immune from liability under § 9607(d)(2) of CERCLA, which provides
    immunity for local governments from costs and damages resulting from
    their emergency response to the potential release of hazardous
    substances.55 See Davis III, 20 F. Supp. 2d at 335. On appeal, UTC
    argues that the district court erred in applying § 9607(d)(2) by
    failing to consider whether Jersey City voluntarily removed the 2,000
    54Even if we concluded that UTC introduced evidence that was
    relevant only to prove that Macera was liable as an arranger, we agree
    with the district court's determination that Macera did not acquiesce
    to being tried on that theory. As the district court noted in its
    ruling from the bench, Macera objected to the use of the word
    "arranger" at least twice during the trial.
    55   Section 9607(d)(2) provides:
    No state or local government shall be liable under this
    Title for costs or damages as a result of actions taken in
    response to an emergency created by the release or
    threatened release of a hazardous substance generated by or
    from a facility owned by another person. This paragraph
    shall not preclude liability for costs or damages as a
    result of gross negligence or intentional misconduct by the
    State or local government.       For the purposes of the
    proceeding sentence, reckless, willful, or wanton misconduct
    shall constitute gross negligence.
    
    42 U.S.C. § 9607
    (d)(2).
    - 110 -
    drums.
    The facts relating to Jersey City's waste disposal are not
    disputed. On a night in February 1977, Jersey City police caught Perk
    Chemical Company dumping waste at an abandoned city warehouse at a pier
    on the Hudson River. After police discovered approximately 2,000 drums
    of waste, the city secured the warehouse. City officials quickly
    contacted the New Jersey Department of Environmental Protection (DEP),
    which determined that the drums contained potentially explosive
    hazardous chemicals that could cause serious environmental harm. Both
    Jersey City and the New Jersey DEP agreed that the waste required
    prompt disposal, but disputed who should finance the cleanup.
    Two weeks later, the DEP obtained a judgment ordering Jersey
    City to fund the cleanup.      After contacting state-recommended
    contractors and expediting the normal bidding process, the city quickly
    hired a contractor to remove the waste. Within a few weeks all of the
    waste was successfully removed from the warehouse. The contractor hired
    by the city subcontracted with CCC to transport the waste for disposal.
    UTC argues that the statute contains a requirement of
    voluntary action that Jersey City did not satisfy because it only acted
    to dispose of the drums after the state obtained a judgment ordering
    the city to pay for the cleanup.56 We review the district court's
    56UTC also argues that Jersey City is not exempt because it owned
    the pier warehouse in which the waste was dumped, meaning that the
    waste cannot be "from a facility owned by another person," as the
    - 110 -
    application of § 9607(d)(2) de novo. See Rivera, 
    131 F.3d at 224
    . To
    construe the statute, we look at its plain language. See 
    id.
     If the
    meaning of the language is clear, our inquiry need go no further.
    See 
    id.
     We construe the statutory language within the context of
    CERCLA as a whole. See 
    id. at 225
    ; Conroy v. Aniskoff, 
    507 U.S. 511
    ,
    515 (1993) ("[T]he meaning of statutory language, plain or not, depends
    on context.").
    According to the plain language of § 9607(d)(2), state and
    local governments are immune except in cases where their handling of
    the waste amounts to "gross negligence or intentional misconduct."
    Although UTC concedes that Jersey City was not grossly negligent and
    did not engage in intentional misconduct, it argues that CERCLA's broad
    remedial purpose requires us to read a voluntariness requirement into
    the statute.
    There is nothing in the plain language of § 9607(d)(2) that
    supports UTC's argument. Indeed, UTC seeks to add to the statutory
    language on policy grounds. There is no basis for doing so. This is
    not the rare case in which applying the plain language of the statute
    will produce an absurd or irrational result, Conservation Law Found. v.
    Busey, 
    79 F.3d 1250
    , 1267 (1st Cir. 1996), or one that is "demonstrably
    at odds with the intention of its drafters," United States v. Ron Pair
    statute requires. 
    42 U.S.C. § 9607
    (d)(2). However, the statute also
    offers immunity if the hazardous waste at issue was "generated by . .
    . another person," as was the case here. 
    Id.
    - 110 -
    Enters., 
    489 U.S. 235
    , 242 (1989).57     We thus affirm the district
    court's ruling that Jersey City is immune from liability under §
    9607(d)(2).
    c. The Government's $6 Million Enforcement Costs
    UTC appeals the district court's apparent ruling that it is
    solely responsible for $6 million in government enforcement costs,
    arguing that the ruling is "insufficiently clear for purposes of the
    application of estoppel and res judicata," and that there is no
    competent evidence to support the conclusion that UTC caused all of the
    government's enforcement costs. The appellants respond that the court
    "properly exercised its discretion in allocating $6 million in
    government enforcement costs to UTC," either based on equitable
    contribution or divisibility principles, and that there is evidence in
    the record to support this ruling.
    The "enforcement costs" at issue are the government's
    expenditures for litigating the cost recovery action against UTC and
    the other original eight defendants through the Phase I trial against
    57 Our application of the statute is consistent with the 6th
    Circuit's opinion in United States v. Cordova Chem. Co., 
    113 F.3d 572
    (6th Cir. 1997), vacated on other grounds sub nom United States v.
    Bestfoods, 
    524 U.S. 51
     (1998). In Cordova, the 6th Circuit found the
    Michigan Department of Natural Resources immune from liability under §
    9607(d)(2) for the costs of a hazardous waste site cleanup. See id. at
    582. We note that the facts of Cordova indicate that the Michigan
    department received immunity for an emergency response that was
    considerably less efficient and effective then Jersey City's here.
    - 110 -
    UTC.58    The district court made two statements about UTC's
    responsibility for these costs. In its September 28, 1998 judgment
    based on partial findings, the court said:
    In this case, calculating UTC's pro rata share of
    the total response costs requires that the
    enforcement cost component and the cleanup cost
    component be considered separately. The $6
    million in enforcement costs is attributable,
    almost entirely, to the Phase I litigation
    between the government and UTC. The defendants
    did not participate in that phase of the
    litigation and it was necessitated because UTC
    denied that any of its waste was deposited at the
    Davis site. Accordingly, UTC bears 100% of the
    responsibility for those enforcement costs.
    Davis III, 20 F. Supp. 2d at 338. The court also discussed the issue
    of enforcement costs in its December 15, 1998 declaratory judgment,
    saying:
    It appears that the [$6 million] enforcement
    costs are attributable almost entirely to
    expenses incurred by the government in the Phase
    I litigation against UTC, and that, therefore,
    they should be borne entirely by UTC. However,
    that issue need not be decided in order to
    determine the likelihood that UTC will be
    required to pay more than its fair share.
    58The parties do not contest that $6 million is an accurate
    estimate of the amount of the government's costs to that point.
    However, UTC argues that the precise figure for the costs --
    $5,855,812.01, according to the government's written submission in
    support of entry of its consent decree with UTC and other settling
    parties -- as well as other evidence about who bears responsibility for
    these costs comes from the consent decree proceedings, and so is not
    part of the record in the declaratory judgment appeals. Because we
    remand to the district court for clarification, we do not reach this
    issue.
    - 110 -
    Davis IV, 
    31 F. Supp. 2d at 69
    . The court denied UTC's motion seeking
    amendment or clarification of these statements.
    UTC argues that the "the equivocal language that the district
    court used and the context of the issue it was deciding indicate it was
    only engaging in a presumption, based on extra-record evidence, to test
    whether it should issue declaratory relief." It asks us to construe the
    court's statements as "argumentative presumptions without preclusive
    effect."
    We agree that the intended effect of the court's statements
    is insufficiently clear. The court discussed UTC's responsibility for
    the government's enforcement costs only in terms of its assessment of
    whether UTC paid more than its fair share of the total response costs
    for the Davis site. On the one hand, the court's initial statement
    that "UTC bears 100% of the responsibility for those enforcement costs"
    suggests that the court may have intended a ruling that obligates UTC
    to pay the government $6 million on top of the payments agreed to in
    the settlement. On the other hand, the court's later statement that
    the issue of UTC's responsibility for the costs "need not be decided"
    suggests that the court ultimately refrained from reaching this
    question.
    Moreover, it is not clear how the court's statements fit with
    its other Phase I and Phase III rulings. Did the court intend merely
    to restate the joint and several liability findings against UTC
    - 110 -
    following the Phase I trial, which indisputably included liability for
    an estimated $49 million in cleanup costs and $6 million in enforcement
    costs?59 Or did the court intend to allocate the enforcement costs to
    UTC, irrespective of the consent decree settlement and the finding that
    UTC should bear 1.54 percent share of the total liability?
    The appellants argue that an equitable allocation to UTC of
    the government's enforcement costs would lie within the district
    court's broad discretionary authority under CERCLA. See Acushnet, 
    191 F.3d at 77
    . However, we are not willing to assume that the court made
    such a finding of causation or equitable allocation without a more
    complete explication. As a result, we instruct the district court on
    remand to explain the intended effect of its statements about UTC's
    responsibility for the government's enforcement costs.60 In remanding
    for clarification of this issue, we do not retain jurisdiction of the
    case. See Clauson v. New England Ins. Co., 
    254 F.3d 331
    , 342 (1st Cir.
    59By order of May 5, 1995, UTC was adjudged liable for "all
    unreimbursed costs that have been incurred by the United States of
    America related to the Davis Liquid Waste Site."
    60This remand does not disturb the district court's finding that
    UTC paid more than its fair share of the total enforcement costs. As
    we have noted, the court translated UTC's 1.54 percent share of
    liability into $754,600 and said that UTC will pay the government at
    least $10.35 million after contribution is received from the settling
    third and fourth-party defendants. Thus "even if the $6 million in
    enforcement costs is viewed as an additional part of UTC's contribution
    threshold, the threshold clearly is exceeded by UTC's settlement
    obligation of at least $10.35 million." Davis IV, 
    31 F. Supp. 2d at 69
    .
    - 110 -
    2001).
    IV. Conclusion
    As a final note, we wish to acknowledge the district court's
    careful attention to this unusually complex case.       Its skillful
    management of the case and its cogent decisions over many years
    considerably aided our disposition of this ganglion of appeals.
    For all of the reasons discussed herein, we affirm the
    determinations of the district court, with the exception of that
    concerning the issue of whether UTC is solely responsible for $6
    million in government enforcement costs. On that issue, we remand for
    a clarification of the district court's position. Each party is to
    bear its own costs.
    So ordered.
    - 110 -
    APPENDIX I
    A Roster of Parties, Principals, and Witnesses
    Acco-Bristol:               defendant found liable for dumping
    Ashland:                    defendant found liable for dumping; also
    appeals the consent decrees
    BFI:                        alleged to be corporate successor of
    Macera Brothers; won judgment on partial
    findings at the close of UTC's evidence
    Black & Decker:             found to be corporate successor of Gar
    Anthony Capuano:            principal of Sanitary Landfill
    Jack Capuano:               principal of Sanitary Landfill
    William Carracino:          principal of CCC
    Robert Cece:                principal of Macera Brothers
    Chemical Control
    Corporation (CCC):          waste hauler located in New Jersey
    Chemical Waste
    Removal (CWR):              waste hauler located in Connecticut
    William Davis:              owner of the Davis site
    Electroformers:             found not to be corporate successor of
    Gar
    Johnny Granfield:      driver for CWR
    Wilbert Jones:              driver for CWR
    Macera Brothers:            waste hauler that dumped at the Davis
    site; won judgment on partial findings
    at the close of UTC's evidence
    John Mayo:                  driver for CCC
    Morton:                     defendant found liable for the dumping
    of Thiokol; acknowledges successor
    - 110 -
    liability for Thiokol
    Emanuel Musillo:      principal of CWR
    Michael Musillo:      principal of Drum Automation, CWR's
    corporate successor
    City of New Jersey:   won judgment on partial findings at the
    close of UTC's evidence
    Perkin-Elmer (PE):    defendant found liable for dumping
    John Prahm:           employee of CCC
    Qualitron:            corporation that dumped at the Davis
    site; PE acknowledges successor
    liability for Qualitron
    Sanitary Landfill:    landfill where CWR and CCC dumped waste
    before dumping at the Davis site
    United Technologies
    Corporation (UTC):    found liable in Phase I; sued third and
    fourth-party defendants in Phase III
    - 111 -
    APPENDIX II
    A Summary of Relevant Monetary Sums
    Estimated Total Cost: $55 million
    Initial EPA response costs: $19 million
    Initial DOJ enforcement costs: $6 million
    Soil remediation: $14 million
    Groundwater cleanup: $13 million
    Water line extension: $3 million
    Phase I
    Partial Consent Decree: approximately $5.625 million
    Clairol: $3 million, plus interest
    Pfizer: $1.5 million, plus interest
    Providence Journal: $650,000, plus interest
    Ciba-Geigy: $475,000, plus interest
    Phase II
    Consent Decree I: $13.5 million, plus $440,000 for government
    oversight costs and the expense of soil remediation
    American Cyanamid: $2.75 million (portion to settle state claims)
    Olin Hunt: $2.75 million (portion to settle state claims)
    Forty-seven non-carve-out parties: $7.2 million
    UTC:      Remainder of settlement, approximately $2.8 million
    Soil remediation, estimated at $14 million
    (UTC contribution action recoveries to be split with the
    United States after deduction of attorneys' fees; UTC
    recovery capped at $5.364 million)
    Consent Decree II: $4.135 million (part to U.S. and part to UTC)
    Twenty-three non-carve-out parties: $4.135 million
    Consent Decree III: $5 million (part to U.S. and part to UTC)
    National Starch: $5 million
    Consent Decree IV: $200,000 (part to U.S. and part to UTC)
    Swan Engraving: $150,000
    - 112 -
    Power Semiconductors: $50,000
    Capuano Consent Decree: $200,000
    Capuano Brothers: $200,000
    Total from Partial Consent Decrees, Phase I and II: approximately $33
    million (not including interest on escrowed amounts)
    - 113 -