## United States Court of Appeals FOR THE EIGHTH CIRCUIT

___________ No. 10-1468

___________ Morrison Enterprises, LLC, *
* Plaintiff/Appellant, *
* City of Hastings, Nebraska, *
* Plaintiff, *
* v. *
* Dravo Corporation, * * Defendant/Appellee. *
* __________________ *
* United States, *
* Amicus on Behalf * of Appellee. *

___________ Appeals from the United States No. 10-1469 District Court for the ___________ District of Nebraska.

Morrison Enterprises, LLC, *
* Plaintiff, *
*-2- City of Hastings, Nebraska, *
* Plaintiff/Appellant, *
* v. *
* Dravo Corporation, * * Defendant/Appellee. *
* __________________ *
* United States, *
* Amicus on Behalf * of Appellee. *

___________ Submitted: November 17, 2010 Filed: April 5, 2011

___________ Before RILEY, Chief Judge, MELLOY and GRUENDER, Circuit Judges.

___________ RILEY, Chief Judge. Morrison Enterprises, LLC (Morrison) and the City of Hastings, Nebraska (City) (collectively, appellant s), and Dravo Corporation (D ravo) are liable within the meaning of the Comprehensive Environmen tal Response, Compensation, and Liability Act of 1980 (CERCLA), as am ended, 42 U. S.C. § 9601 et seq. , for hazardous substances released at the Hastings Ground Water Contamination Site (Site). Appellants each sued Dravo under § 107(a) of CERCLA, 42 U.S.C. § 9607(a), seeking to recover some of the costs th ey incurred responding to contaminated ground1 The Honorable Warren K. Urbom, United Stat es District Judge for the District of Nebraska.

2 The NPL is a list of national prioritie s among the known releases or threatened releases of hazardous substances throughout the United States, and serves to identify those sites or releases that appear to warrant further investigation and remedial action. See 42 U.S.C. § 9605(a).
-3- water at the Site. The district court 1 denied appellants’ motions for summary judgment and granted summary judgment to Dravo on appellants’ cost-recovery claims. The district court held (1) CERCLA § 113(f), 42 U.S.C. § 9613(f), provided appellants’ exclusive remedy to rec over response costs incurred removing contaminants from the City’s ground water, and (2) the City’s water supply system claims were untimely. We affirm.

I. BACKGROUND A. Facts In 1983, the City attempted to restor e a long-closed water production well to service, but immediately received complain ts about the water’s foul taste and odor. Responding to the complaints, the Nebraska Department of Health (NDOH) and the United States Environmental Protecti on Agency (EPA) began investigating contamination in the City’s wells. On June 10, 1986, the EPA added the Site to the National Priority List (NPL). 2

In 1985 and 1986, the EPA notified a number of entities, including Morrison, the City and Dravo, that they were potentially liable under CERCLA for releases and threatened releases of hazard ous substances at the Site. The EPA determined the contamination at the Site originated fromseven source areas, or subsites, three of which are relevant to these appeals: th e FAR-MAR-CO Subsite, the Colorado Avenue Subsite and the North Landfill Subsite. Hazardous substances from each of the subsites entered the City’s ground water and were remediat ed in part by the operation of the “Well-D system” (Well-D), a gr ound water extraction and treatment system-4- located at the FAR-MAR-CO Subsite, down gradient of the relevant sources of contamination at all three subsites.

The EPA identified Morrison as potentia lly liable at the FAR-MAR-CO Subsite for response costs necessary to remediate re leases of hazardous substances at a grain elevator owned and operate d by one of Morrison’s predecessors. Dravo and others were identified as potentially liable at th e Colorado Avenue Subsite for releases of trichloroethylene (TCE) and other volatile organic compounds (VOC) in connection with the use of a solvent containing TCE as a degreaser in manufacturing operations at the site. The City, Dravo, and others were identified as potentially liable for releases of TCE and other contaminants of concern (COC) at the North Landfill Subsite, a former landfill operated by the C ity. During the City’s operation of the landfill, Dravo disposed of industrial waste containing TCE there.

1. FAR-MAR-CO Subsite In 1991, Morrison entered into the first of a series of administrative settlements with the EPA, known as administrative orde rs on consent (AOC), pursuant to which Morrison agreed to perform designate d clean-up activities at the FAR-MAR-CO Subsite. In 1996, Morrison entered into a s econd AOC, pursuant to which Morrison agreed to operate Well-D to extract and treat ground water at the FAR-MAR-CO Subsite and reimburse the EPA for response costs incurred at the subsite.

One stated purpose of the 1996 AOC was to reduce three specific COCs found in ground water at the FAR-MAR-CO Subsite at concentrations hazardous to human health and the environment—TCE, carbon te trachloride (CT), and ethylene dibromide (EDB). Having been found a “liable party” by the EPA within the meaning of § 107(a), Morrison agreed to finance and operate Well-D to remove each of those COCs. Well-D has been operating since 1997. Morrison maintains it has never used or released TCE anywhere within the S ite and that the FAR-MAR-CO Subsite has never been identified as a source of TCE.-5- In September 2007, the EPA issued a r ecord of decision for the FAR-MAR-CO Subsite requiring the extraction of contaminated ground water at Well-D. On July 29, 2008, the EPA filed a civil action in the district court against Morrison under §§ 106 and 107, seeking an order compelling Morri son to operate Well-D and reimburse the EPA for response costs incurred at the FA R-MAR-CO Subsite. In a consent decree filed October 8, 2008, the EPA and Morri son resolved Morrison’s potential liability for contamination at the Site under §§ 106 and 107. The 2008 consent decree continued to rely on Well-D as the primary method of cleaning ground water at the subsite.

In addition to contaminants origina ting at the FAR-MAR-CO Subsite, ground water extracted and treated at Well-D contains TCE and other contaminants originating at the Colorado Av enue and North Landfill Subsite s. In agreements dated June 1995 and July 1997, Morrison, the City, and one other party ag reed to coordinate efforts and allocate certain costs associat ed with the investigation and cleanup of releases of hazardous substances fro m the North Landfill and FAR-MAR-CO Subsites. Under those agreements, the C ity contributed to the construction and operation of Well-D. Dravo did not join those agreements.

2. North Landfill Subsite In October 1992, the City entered into an AOC with the EP A pursuant to which the City agreed to undertake certain res ponse actions at the North Landfill Subsite. In 1998, the EPA sued th e City and Dravo under §§ 106 and 107. On August 13, 1998, the City and Dravo jointly entered into a consent decree with the EPA to perform a source-control remedial action at the North Landfill Subsite. Following a second suit by the EPA in 2007, the City a nd Dravo entered a second consent decree requiring the City and Dravo to particip ate in operating Well-D to contain the migration of VOCs in the City’s ground wate r and to coordinate efforts with the responsible parties at the FAR-MAR-CO Subsite. The 2007 consent decree also-6- requires the City and Dravo to pay the EPA’s response costs and provides contribution protection to the settling parties.

3. Colorado Avenue Subsite In 1993, the EPA issued a unilateral administrative order requiring Dravo to remediate soil and ground water contamination at the Colorado Avenue Subsite. Several of the City’s water production wells are within the vicinity of the Colorado Avenue Subsite and were contaminated w ith TCE. At the recommendation of the NDOH, the City removed the c ontaminated wells from service and relocated parts of its water supply system by installing ne w wells, mains, and related improvements. Though the exact date is unknown, the C ity began its ongoing efforts to provide alternative water supplies at least as early as 1986.

On September 27, 2001, the government sued Dravo under § 107(a) to recover costs incurred in response to the release of hazardous substances at the Colorado Avenue Subsite. See United States v. Dravo , No. 8:01CV500 (D. Neb. filed Sept. 27, 2001). On November 26, 2001, Dravo joinedthe City as a third-party defendant, seeking contribution from the City for the federal government’s response costs. The City asserted counterclaims against Dravo for contribution. The City alleged the hazardous substances released by Dravo migrated and contaminated the City’s ground water, requiring water syst em replacements at signifi cant cost to the City.

On January 24, 2006, Dravo and the City entered into a settlement and release agreement to resolve certain cl aims between them. As part of the agreement, the City reserved its claims against Dravo for any contamination migrating from the Colorado Avenue Subsite to other locations in the Site, including Well-D. On May 24, 2006, the district court approved a consent decr ee requiring Dravo to take various actions to clean up TCE contamination at the Colorado Avenue Subsite.-7- B. Prior Proceedings On July 3, 2008, appellant s filed a seven-count comp laint against Dravo setting forth the following causes of action: cost recovery under § 107 (Count I); declaratory judgment under § 113(g)(2) (Count II); noncontractual indemnity (Count III); negligence (Count IV); private nuisance (C ount V); public nuisance (Count VI); and trespass (Count VII). Appellants jointly brought Count s I and II. Morrison brought Count III alone, and the City brought Counts IV-VII alone. Neither Morrison nor the City brought a claim for contribution under § 113(f). In its answer, Dravo pled as its second affirmative defense that appella nts could not rec over under § 107 because “their claims [were] for contribution.” Appellants moved to strike the defense, arguing Dravo’s defense would only confuse the issues.

On November 6, 2008, the district cour t denied the motion, noting there were material disputed factual issues re garding the source of TCE at Well-D. The district court also stated Morrison had failed to es tablish Dravo’s defense was insufficient as a matter of law. The district court’s scheduling or der established February 13, 2009 as the deadline for filing moti ons to amend the pleadings.

On February 24, 2009, appellants amende d their complaint, adding a breach of contract claim (Count VIII). Appellant s brought Counts I-III jointly and the City brought Counts IV-VIII alone. Appellants di d not include a contribution claim under § 113(f).

On March 6, 2009, Dravo answered th e amended complaint and filed four counterclaims against appellants. Counter claims I-III consisted of contribution and indemnification claims contingent on Dravo being found liable to appellants. Counterclaim IV alleged Dravo was entitle d to reimbursement from appellants for Well-D costs incurred in connection with th e North Landfill Subsite. Dravo continued to include its affirmative defense asserting appellants were barred from pursuing a § 107(a) claim.3 The district court also dismissed Counts IV-VII, which the City does not appeal.
-8- On June 19, 2009, Dravo moved for pa rtial summary judgment on the City’s water supply system claims, arguing the C ity’s § 107 cost-recovery claim was barred by the applicable statute of limitations. Finding the replacement of the City’s water system to be a remedial action ratherthan a removal action under CERCLA, the district court dismissed the City’s cl aims under Counts I a nd II as time-barred. 3 The district court also rejected the City’s ar gument that the present case was a “subsequent action” for response costs because the City’s purported “initial action” (a counterclaim in an earlier action) unambiguously was one for contribution only.

On July 15, 2009, Dravo again moved fo r partial summary judgment, this time on appellants’ Well-D claims, arguing appe llants could not pursue a cost-recovery action under § 107. That same date, appellants moved for summary judgment on Dravo’s liability under § 107 a nd Dravo’s counterclaims. On November 24, 2009, the district court granted Dravo’s motion inpart, finding § 113(f) provided appellants’ exclusive remedy. The district court deni ed as moot appellants’ motions for summary judgment with respect to Counterclaims I-III and Dravo’s liability under § 107. The district court granted the City’s motion for summary judgment on Counterclaim IV and Dravo voluntarily dismissed Countercl aim IV against Morrison. The City voluntarily dismissed Counts III and Count VIII.

After the district court dismissed Morrison’s § 107 claim, Morrison sought leave to amend its complaint to assert a claim under § 113. The district court denied the motion, deciding Morrison failed to demonstrate good cause and did not act diligently in its efforts to meet the sche duling order. The district court entered judgment January 26, 2010. A ppellants appeal the district court’s summary judgment rulings on Counts I and II. Morrison also appeals denial of its motion for leave to amend.-9- II. DISCUSSION A. Standards of Review “We review the district court’s grant of summary judgment de novo .” Cole v. Homier Dist. Co. , 599 F.3d 856, 864 (8th Cir. 2010). “Summary judgment is appropriate when the record, viewed in the light most favorable to the non-moving party, demonstrates that there is no genuine issue of material fact and the moving party is entitled to judgment as a matter of law.” Myers v. Lutsen Mtns. Corp. , 587 F.3d 891, 893 (8th Cir. 2009). See also Fed. R. Civ. P. 56(a) (amended effective Dec. 1, 2010). We also review the distri ct court’s interpretation of CERCLA de novo . See Atl. Research Corp. v. United States , 459 F.3d 827, 830 (8th Ci r. 2006). We review the district court’s denial of Morrison’s motion for leave to amend for an abuse of discretion. See Doe v. Cassel , 403 F.3d 986, 990 (8th Cir. 2005). A district court’s finding of delay is subject to review for clear error. See id.

B. Well-D 1. CERCLA Framework “Two provisions of [CERCLA]—§§ 107( a) and 113(f)—allow private parties to recover expenses associated with clean ing up contaminated sites.” United States v. Atl. Research Corp. , 551 U.S. 128, 131 (2007). Though complementary, “§§107(a) and 113(f) provide two ‘clearly distinct’ remedies,” id. at 138, “to persons in different procedural circumstances,” id. at 139 (quotation omitted) . Section 107(a)(4)(B) permits a private party who has voluntarily incurred costs cleaning up a site for which it may be held liable to recover necessary response costs from another liable party through a direct recovery action. See id. at 133-34, aff’g Atl. Research Corp. v. United States , 459 F.3d 827 (8th Cir. 2006).

Section 113(f), enacted after § 107 as pa rt of the Superfund Amendments and Reauthorization Act of 1986 (SARA), Pub. L. No. 99-499, 100 Stat. 1613 (1986), “authorizes one [potentially responsible party] to sue another for contribution in certain circumstances.” Id. at 132. Section 113(f)(1) allows a person to seek-10- contribution from any other person who is liable or pot entially liable under § 107(a) during or following a civil action u nder §§ 106 or 107. Section 113(f)(3)(B) authorizes “[a] person who has resolved its liability to the United St ates 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 settle ment” to seek contribution from any person who has not so resolved its liability.

The term “contribution” has its traditional meaning of a “tortfeasor’s right to collect from others responsible for the same to rt after the tortfeasor has paid more than his or her proportionate share, the shares be ing determined as a pe rcentage of fault.” Atl. Research , 551 U.S. at 138 (quoting Black’s Law Dictionary 353 (8th ed. 2004)). The “right to contribution under § 113(f)( 1) is contingent upon an inequitable distribution of common liability among liable parties.” Id. at 139.

The right to contribution under § 113(f) is more limited than the right to recover costs under § 107(a). See Atl. Research , 459 F.3d at 832. A person seeking contribution under § 113(f) may be subject to the equitable allocation of response costs, see § 113(f)(1), and may not recover fro m previously settling parties, see § 113(f)(2). Such claims are also subordinateto the rights of th e United States or a State, see § 113(f)(3)(C), and subject to a shorter limitation period than cost-recovery claims, see § 113(g)(2)-(3).

To ensure the continued vitality of the precise and limited right to contribution Congress set forth in § 113, we have held the right to bring a cost-recovery action under § 107 “is available to parties who haveincurred necessary costs of response, but have neither been sued nor settled thei r liability under §§ 106 or 107.” Atl. Research , 459 F.3d at 835. “[L]iable parties whic h have been subject to §§ 106 or 107 enforcement actions are still required to use § 113.” Id. at 836-37. See also , Niagara Mohawk Power Corp. v. Chevron U.S.A., Inc. , 596 F.3d 112, 128 (2d Cir. 2010) (holding that allowing a liable party whose claims fit § 113(f) “to proceed under §-11- 107(a) would in effect nullify the SARA amendment and abrogate the requirements Congress placed on contribution claims under § 113”); ITT Indus., Inc. v. BorgWarner, Inc. , 506 F.3d 452, 458 (6th Cir. 2007) (“ To maintain the vitality of § 113(f), however, [potentially responsible parties] who have been subject to a civil action pursuant to §§ 106 or 107 or who have entered into a judicially or administratively approved settlement mu st seek contribution under § 113(f).”).

In affirming our decision in Atlantic Research , the Supreme Court noted the potential for overlap between §§ 107(a) and 113 (f), but declined to decide whether a liable party sustaining expenses pursuant to a consent decree following a suit under §§ 106 or 107(a) could recover such compe lled costs under § 107(a), § 113(f), or both. Atl. Research , 551 U.S. at 139 n.6. We necessarily reach that issue in these appeals, and hold that § 113(f) provides the exclusiv e remedy for a liable party compelled to incur response costs pursuant to an administrative or judicially approved settlement under §§ 106 or 107. See Atl. Research , 459 F.3d at 830 n.4 (explaining our holding in Dico, Inc. v. Amoco Oil Co. , 340 F.3d 525, 531 (8th Cir. 2003), that a liable party cannot bring an action under § 107 “remains viable for those parties which still have recourse to relief under § 113”).

2. Morrison’s Response Costs for Well-D The district court determined Morris on could not use § 107(a) to recover response costs for removing TCE at Well-D because Morrison was a liable party that had been subject to a § 107 enforcement action as evidenced by the amended 1991 AOC, the 1995 AOC amendments, the 1996 AOC, and the 2008 consent decree, which obligated Morrison to operate We ll-D to remove TCE and other hazardous substances.

Morrison contends the district court e rred in finding Morrison could not bring a cost-recovery action because, in Morris on’s view, it “voluntarily” cleaned up TCE contamination for which Dra vo was legally liable. De nying any causal connection to-12- releases of TCE anywhere in the Site, Mo rrison attempts to analogize its compelled removal of TCE at Well-D to the plaintiff’s voluntary clean up of hazardous substances in Atlantic Research . According to Morrison, “[b]y ‘voluntarily,’ the Supreme Court [in Atlantic Research ] meant actions taken ‘without any establishment of liability to a third party,’ such as through a judgment or court order.” See Atl. Research , 551 U.S. at 139. Mo rrison’s understanding of Atlantic Research and its application here is incorrect.

Morrison ignores the terms of the AOCs by which it is bound. Unlike the voluntary plaintiff in Atlantic Research , which had never been subject to an action under §§ 106 or 107, Morrison has been suedunder § 107 for releases and potential releases of hazardous substances at the FAR-MAR-CO Subsite and entered administrative settlements to resolve its liability. Notwithstanding Morrison’s assertions to the contrary, the 1996 AOC specifically obligates Morrison to operate Well-D to remove TCE from contaminated ground water as a “liable party” under § 107(a). Morrison is subject to penalties if it fails to do so. Response costs incurred pursuant to such administrative settleme nts following a suit under § 106 or § 107(a) are not incurred voluntarily. See Atl. Research , 551 U.S. at 139 n.6. The district court correctly concluded Morris on could not maintain a cost-recovery action under § 107(a).

3. City’s Response Costs for Well-D The City likewise did not voluntarily incur response costs operating Well-D. As thoroughly explained by the district court, the City was subject to enforcement under §§ 106 and 107 and resolved its liab ility to the federal government in administrative and judicially approved settlements, including the 1992 AOC, the 1998 consent decree, the 2004 AOC, and the 2007 consent decree, culminating in the operation of Well-D to remediate cont amination in the City’s ground water.-13- Analyses of the City’s ground water between 1985 and 1995 revealed contamination down gradient of the North Landfill Subsite caused by the release of TCE. Noting “the past, present or pot ential migration of hazardous substances currently located at or emanating from the Subsite, constitutes actual and/or threatened ‘releases,’” the 1992 AOC obligated the City , as a liable party, to perform certain remedial actions at the site. The 1998 consent decree and the 2004 AOC also address the City’s liability for migrating TCE. By the City’s own account, the 2007 consent decree requires the City “to fi nance and perform the work necessary to implement the specified remedies, including continued operation of the Well-D System to contain the migration of TCE plumes.” The C ity has not operated Well-D voluntarily.

The City contends its participation in settlements at the North Landfill Subsite does not preclude a cost-recovery action ag ainst Dravo under § 107(a). In support of this assertion, the City cites three cases, W.R. Grace & Co.-Conn. v. Zotos Int’l, Inc. , 559 F.3d 85, 91-93 (2d Cir. 2009), Kotrous v. Goss-Jewett Co. of N. Cal., Inc. , 523 F.3d 924, 934 (9th Cir. 2008), and Schaefer v. Town of Victor , 457 F.3d 188, 191-92, 201-02 (2d Cir. 2006), each permitting a § 107 action.

We agree with the district court that each of the City’s cases is distinguishable. Unlike the City, none of the pl aintiffs in the cited cases had resolved its § 107 liability, nor entered into administrative or judicia lly approved settlements within the meaning of § 113(f). See W.R. Grace , 559 F.3d at 91-93; Kotrous , 523 F.3d at 927; Schaefer , 457 F.3d at 191-92. This difference deprives those cases of any persuasive value.

The City contends the district court erred in focusing on the remedy, Well-D, rather than Dravo’s liability for contamin ation originating at the Colorado Avenue Subsite, which the City stresses is a separate “facility” under CERCLA. According to the City, each of the settle ments the City entered addre ssed its liability at the North Landfill Subsite, not the Colorado Avenue Subsite, making the City’s construction,-14- operation and maintenance of Well-D to clean up contamination from the Colorado Avenue Subsite voluntary.

The City’s focus on specific facilities w ithin the Site is entirely too narrow given CERCLA’s comprehensive remedial purpose and broad reach. See , e.g. , Control Data Corp. v. S.C.S.C. Corp. , 53 F.3d 930, 936 (8th Cir. 1995). The term “facility” includes “any site or area where a hazardous substance has been deposited, stored, disposed of, or placed, or othe rwise come[s] to be located.” 42 U.S.C. § 9601(9)(B). Under § 107(a), “[ l]iability is strict and is typically joint and several.” United States v. Hercules, Inc. , 247 F.3d 706, 715 (8th Cir. 2001). “[O]nce a party is liable [under § 107(a)], it is liable for its sh are, as determined by [§ 113(f)], of ‘any’ and all response costs, not just those cost s ‘caused’ by its release.” Control Data , 53 F.3d at 936.

Some of the releases of hazardous substa nces for which the City and Dravo are liable may have initially originated at diffe rent subsites, but both are responsible for the release of TCE into the City’s ground water within the S ite. Because the TCE contamination from the North Landfill Subsite and the Colorado Avenue Subsite has migrated to the FAR-MAR-CO Subsite, the district court correctly concluded the Citymust use § 113(f) to allocate responsibility for response costs incurred operating WellD to remove TCE accumulating there.

4. Common Liability In an argument closely related to Morrison’s claim it voluntarily incurred response costs for TCE, Morrison contends it could not seek contribution from Dravo pursuant to § 113(f) because Morrison and Dr avo released different contaminants at different facilities. In Morrison’s view, because Morrison has never been subject to liability under § 107 for response costs nece ssary to address TCE from the Colorado Avenue Subsite or anywhere else, Morri son does not, as a matter of law, share “common liability” with Dravo necessary to support an action under § 113(f).-15- The City similarly argues it does not have a right of contribution against Dravo because the City is not liable for hazardous substances released at the Colorado Avenue Subsite. According to the City , neither the AOCs and consent decrees by which it is bound, nor its operation of Well- D create any common liability with Dravo because “[c]ommon liability arises out of c onduct leading to an indivisible harm - not a single solution (i.e. the Well D System) to multiple, divisible harms.”

In its amicus brief, the United Stat es asserts appellant s’ interpretation “fundamentally misconstrue[s] liability under CERCLA.” We agree. “Under CERCLA, if a responsible party . . . re leases hazardous materials into the environment, and that release ‘causes the in currence of response costs,’ then the party is liable . . . . for ‘ any other necessary cost of res ponse incurred by any other person consistent with the national c ontingency plan.’” Control Data , 53 F.3d at 936 (quoting 42 U.S.C. § 9607(a) (emphasis in Control Data )). “CERCLA focuses on whether the defendant’s release or threatened release cau sed harm to the plaintiff in the form of response costs.” Id. at 935; see also Hercules , 247 F.3d at 715-17 (explaining “it is enough that response costs resulted from ‘a’ release or threatened release—not necessarily the defendant’s release or threatened release”) (quoting 42 U.S.C. § 9607(a)(4)).

When multiple parties are liable for res ponse costs, the focus then shifts to allocation. See Hercules , 247 F.3d at 715. “Allocation is a contribution claim controlled by [§ 113(f)].” Control Data , 53 F.3d at 935.

Applying the foregoing private cost-recovery framework in Control Data , a factually similar case, we affirmed the trial court’s allocation of response costs between liable parties based, in part, on the relative toxic ity of the distinct hazardous substances each released into the ground water at different sites. Id. at 932-34, 937- 38. Control Data owned and operated a facility thatinadvertently discharged trichloroethane (TCA) in to ground water. Id. at 932. While testing the ground water-16- beneath its facility, Control Data discove red tetrachloroethylene (PERC), which had been released by Schloff Chemical at a different facility. Id. at 932-33. Control Data installed a remediation system that simu ltaneously removed both TCA and PERC. Id. at 933.

We held Control Data could seek c ontribution from Schloff for the operation of the remediation system and the inves tigation of the ground water contamination because, “[b]y not reacting and allowing the PERC plume to migrate, [Schloff] became partially responsible for the hazardous condition of the Control Data site.” Id. at 936. We reach the same conclusion w ith respect to appellants’ ability to seek contribution from Dravo for response costs incurred operating Well-D to remove TCE that migrated from the Colorado Avenue Subsite from the City’s ground water.

As the United States points out, Well-D removes hazardous substances for which Morrison, the City and Dravo are each responsible, making them jointly and severally liable for response costs incurred to operate it. Morrison is liable for operating Well-D to remove TC E, CT and EDB which have migrated into the City’s ground water at the FAR-MAR-CO Subsite. The City is liable for operating Well-D to remove TCE and other h azardous substances released at the North Landfill Subsite. And Dravo is liable for response costs to operate Well-D to remove TCE released at the Colorado Avenue Subsite. Indeed, the 2007 consent decree requires Dravo and the City to coordinate peri odically with Morrison “to ensure the continued operation of Well D.”

Morrison, the City and Dravo share liability for contaminating the City’s ground water. They also share liability for operating Well-D to remove those contaminants. This shared liability is sufficient to support a § 113(f) contribution claim. Many of the factors appellants have raised with respect to common liability may be relevant to the proper allocati on of liability and response costs among the parties but do not prevent appellants from seeking contribution from Dravo, subject4 The United States as amicus suggests § 113(f) provides the exclusive remedy for the City’s alternative water supply syst em claims because the City was sued under §§ 106 and 107, but acknowledges that issue is not before us because Dravo did not argue the exclusivity of § 113(f) before the district court or on appeal.
-17- to any limitations CERCLA places on that ability. See Hercules , 247 F.3d at 715-19 (discussing divisibility of harm); Control Data , 53 F.3d at 935 (listing factors relevant to resolving contribution claims).

C. City’s Water Supply System 4 1. Initial Action The City asserts the district court e rred in finding the statute of limitation expired before the City filed an initial action to recover response costs incurred relocating part of the City’s water supply sy stem. The applicable statute of limitation, CERCLA § 113(g)(2), 42 U.S.C. § 9613(g)(2), provides

An initial action for recovery of the costs referred to in section [107] of this title must be commenced—
(A) for a removal action, within 3 years after completion of the removal action, except that such cost recovery action must be brought within 6 years after a determinati on to grant a waiver under section 9604(c)(1)(C) of this title for c ontinued response action; and
(B) for a remedial action, within 6 years after initiation of physical on-site construction of the remedial action, except that, if the remedial action is initiated within 3 years af ter the completion of the removal action, costs incurred in the removal action may be recovered in the cost recovery action brought under this subparagraph.
Admitting § 113(g)(2)(B) has expired if the C ity’s relocation of part of its water supply system beginning in the 1980s constitute s a remedial action, the City contends § 113(g)(2)(A) applies, but ha s not begun to run because th e City’s work constitutes5 The City argues, for the first time on appeal, its provision of alternative water supplies cannot be a remedial action b ecause the President has not made a determination of cost effectiveness. “Absent exceptional circumstances,” not present here, “we cannot consider issues not raised in the district court.” Shanklin v. Fitzgerald , 397 F.3d 596, 601 (8th Cir. 2005).
-18- an ongoing removal action. Determining whether a response is a removal action or a remedial action requires referen ce to CERCLA § 101(23)-(24), 42 U.S.C. § 9601(23)-(24). Section 101 provides in pertinent part

(23) The terms “remove” or “removal” mean[] the cleanup or removal of released hazardous substances from the environment, such actions as may be necessary taken in the event of the threat of release of hazardous substances into the envi ronment, such actions as may be necessary to monitor, asse ss, and evaluate the releas e or threat of release of hazardous substances, the disposal of removed material, or the taking of such other actions as may be necessary to prevent, minimize, or mitigate damage to the public health or welfare or to the environment, which may otherwise result from a release or threat of release. The term[s] include[], in addition, without being limited to . . . provision of alternative water supplies . . . .
(24) The terms “remedy” or “rem edial action” mean[] those actions consistent with permanent re medy taken instead of or in addition to removal actions in the event of a release or threatened release of a hazardous substance into the environm ent, to prevent or minimize the release of hazardous substances so that they do not migrate to cause substantial danger to present or futu re public health or welfare or the environment. The term[s] include[], but[are] not limited to . . . provision of alternative water supplies . . . .
The inclusion of the provision of altern ative water supplies in both definitions complicates the analysis. Th e parties agree the City’s re placement of wells and mains constitutes the provision of alternative wa ter supplies, but disagree as to which definition describes the City’s actions in this case. 5-19- In construing the statutory language and supporting regulations, we have described removal actions as “those taken to counter imminent and substantial threats to public health and welfare,” while re medial actions “are longer term, more permanent responses.” Minnesota v. Kalman W. Abrams Metals, Inc. , 155 F.3d 1019, 1024 (8th Cir. 1998); see also Exxon Corp. v. Hunt , 475 U.S. 355, 360 (1986) (characterizing a removal action as a “short-term cleanup” and a remedial action as “measures to achieve a ‘permanent re medy’ to a particular hazardous waste problem”). “Generally, a rem oval action costs less, takes less time, and is geared to address an immediate release or threat of release,” wher eas a remedial action, which “usually cost[s] more and take[s] longer,” “seeks to effect a permanent remedy to the release of hazardous substances when th ere is no immediate threat to the public health.” Pub. Serv. Co. v. Gates Rubber Co. , 175 F.3d 1177, 1182 (10th Cir. 1999).

The district court concluded the ongoing activities the City performed for the provision of alternative water supplies cons tituted a remedial action, not a removal action under CERCLA. The district court r easoned the City’s two-and-a-half decades of work were consistent with a permanent remedy for the lack of water that resulted from the closing of contaminated wells, but were not in the natu re of an emergency cleanup or other interim response to an immi nent threat to public health. We agree.

Although neither definition fits perfectly , we conclude the City’s replacement of wells and mains more closely fits the definition of a remedial action. Having already continued for over twenty-five year s, the City’s ongoing relocation of part of its water supply system lacks the immedi acy and relatively short duration of a removal. The City’s hope, that the clean -up actions will eventually return the contaminated wells to service, does not a lter our conclusion that retiring contaminated wells and obtaining uncontaminated supplies of water to meet the needs of the City’s residents for the forseeable future is more in the nature of a permanent remedy.-20- The City contends that, in concluding the City’s work on the water supply system was a remedial action, the district court improperly focused on the phrase “consistent with permanent remedy” while ignoring the phrase “to prevent or minimize the release of hazardous substances .” The City asserts that because the “work on the water supply system did not cl ean one molecule of water or rid the environment of any contamination whatsoever,” that part of the definition of remedial action does not describe water system improvements. The City’s argument is unavailing.

First, the City’s narrow in terpretation of the term re medial action would render Congress’s specific inclusion of the provisi on of alternative wa ter supplies in the second sentence of the definition a nullity. By its inherent nature, the provision of alternative water supplies neve r cleans contaminated water, nor rids the environment of contamination. We “avoid interpreti ng a statute in a manner that renders any section of the statute superfluous or fails to give effect to all of the words used by Congress.” Westerfeld v. Indep. Processing, LLC , 621 F.3d 819, 824 (8th Cir. 2010).

Second, shutting down contaminated we lls and providing a lternative water sources to prevent the City’s residents from drawing and using contaminated water does “prevent or minimize the release of hazardous substances” to protect the public health and welfare. The district court did not err in finding § 113(g)(2)(B) barred the City’s claims for costs incurred relocating parts of its water supply system.

2. Subsequent Action As an alternative to arguing its water s upply system claim is an initial removal action subject to § 113(g)(2)(A), the City contends its claim c onstitutes a subsequent action within the meaning of the flush langua ge of § 113(g)(2), subject to a three-year statute of limitation that has not yet begun to run. Section 113(g)(2) provides in relevant part:-21- A subsequent action or actions under s ection [107] of this title for further response costs at the vessel or facility may be maintained at any time during the response action, but must be commenced no later than 3 years after the date of completion of all response action. The City argues the action against Dra vo in United States v. Dravo Corp. , No. 8:01CV500 (D. Neb. filed Sept. 27, 2001), including the City’s counterclaims for contribution, serves as the initial action fo r purposes of § 113(g)(2). More specifically, the City asserts not only that its § 113 contribution claims constitute an initial action under § 107, but also that, even in the absen ce of a prior claim against Dravo, the City may rely on the government’s initial acti on against Dravo under § 107 to obtain the benefit of the longer limitation period for subsequent actions. In the City’s view, there is no requirement the plaintiff be the same in the initial and subsequent actions, so any prior § 107 claim against the same defendant qualifies as an initial action regardless of the plaintiff. Both arguments are without merit.

We agree with the district court that the City’s previously filed counterclaims against Dravo for declaratory judgment and contribution under § 113(f) do not constitute an initial action to recover response costs under § 107(a). Section 113(g)(2) refers to initial and subse quent actions to recover co sts specifically under § 107, not contribution claims under § 113(g). In a ddition, as Dravo points out, § 113(g)(2)(A) and (B) each set forth a specific limitation period that applies to initial actions. Section 113(g)(3) sets forth a separate limitation period for contribution claims. Allowing a contribution claim to serve as the initial action under § 113(g)(2) would impermissibly subject the action to two different limitation periods. The City’s contention conflicts with the express la nguage and the overall scheme of CERCLA.

We likewise reject the City’s unsupporte d contention that any prior § 107 claim against the same defendant, re gardless of the plaintiff, qualifies as an initial action. Permitting any subsequent plaintiff to obtai n the benefit of the longer limitation period for subsequent actions as the City pr oposes “would largely write the limitations restriction for initial actions out of the statute because many response actions will be-22- ongoing for decades.” United States v. Navistar Int’l Transp. Corp. , 152 F.3d 702, 710 (7th Cir. 1998) (rejecting the government ’s assertion § 113(g)(2) does not require the same defendant in the initial ac tion and the subsequent action). The City’s partial relocation of wells and mains already stretches back more than twenty-five years and is expected to continue into the foreseeable future. Like the defendant in Navistar , under the City’s proposed rule , Dravo could be subject to new private-party claims for decades. See id. We decline to adopt a definition of subsequent action that would discourage the timely filing of cost-recovery actions and frustrate Congress’s intent “to assure that evidence concerning liability and response costs i[s] fresh . . . and to provide some measure of finality to affected responsible parties.” Id. at 707 & n.7 (quoting H.R. Rep. No. 99-253 pt. 1, at 138 (1985), reprinted in 1986 U.S.C.C.A.N. 2835, 2920) (internal quotation marks omitted).

D. Leave to Amend On December 1, 2009, following the distri ct court’s adverse grant of summary judgment, nine months after the February 13, 2009 deadline to file motions to amend the pleadings expired, and just two months before trial, Morrison moved for leave to amend its complaint a second time. When a party moves for leave to amend outside the district court’s scheduli ng order, Fed. R. Civ. P. 16(b), “not the more liberal standard of [Fed. R. Civ. P. 15(a)],” governs and requires the party to show good cause to modify the schedule. Sherman v. Winco Fireworks, Inc. , 532 F.3d 709, 716 (8th Cir. 2008). “The primary measure of good cause is the movant’s diligence in attempting to meet the or der’s requirements.” Id. at 716-17 (quoting Rahn v. Hawkins , 464 F.3d 813, 822 (8th Cir. 2006).

“Post-dismissal motions to amend are disf avored,” In re Medtronic, Inc., Sprint Fidelis Leads Prods. Liab. Litig. , 623 F.3d 1200, 1208 (8th Cir. 2010), because “[m]uch of the value of summary judgment . . . would be dissipated if a party were free to rely on one theory in an attempt to defeat a summary judgment and then, should that theory prove unsound, come back . . . and fight on the basis of some other theory.” Littlefield v. City of Afton , 785 F.2d 596, 610 (8th Cir. 1986) (analyzing-23- Fed. R. Civ. P. 15) ( quotation omitted), overruledin part on other grounds by Lemke v. Cass Cnty., Neb. , 846 F.2d 469, 470-71 (8th Cir. 1987) (en banc) (per curiam).

Morrison contends it demonstrated good cau se to modify the scheduling order because Morrison “could not, in good faith ,” have brought a claim under § 113(f) against Dravo before the district court’s summary judgment rulings, and it acted diligently thereafter. Morrison’s assertion is not persuasive.

As the district court noted, Dravo’s September 8, 2008 answer and October 9, 2008 response to Morrison’s motion to stri ke gave Morrison ample notice Dravo contended § 113(f) provided Morrison’s ex clusive remedy. On November 6, 2008, the district court notified Morrison that Dravo’s defense had merit. Explaining a diligent plaintiff would have made all poten tially viable claims given the complexities of CERCLA, the district court determined Morrison could have reasonably offered an amended complaint before the February 13, 2009 deadline, but chose to pursue its claims under the more generous provisions of § 107(a). The district court did not abuse its discretion in concluding Morris on’s tactical choice did not demonstrate diligence or good cause. Allowing Morrison to amend its complaint after Morrison’s strategy failed would undermine the purpose and effectiveness of summary judgment. See Littlefield , 785 F.2d at 610.

Morrison also asserts the district court failed to consider the prejudice the denial of leave caused Morrison. Ev en if we assume, as Morris on suggests, the requirements of Fed. R. Civ. P. 15 are relevant to our analysis of good cause under Fed. R. Civ. P. 16, Morrison failed to adduce any evidence it ever advised the district court Morrison would be prejudiced. In its motion, Morrison noted only the interests of judicial economy to be served by permitting Morris on to amend its complaint rather than requiring it to file a separate lawsuit.

On appeal, Morrison claims prejudice cau sed by the need for this appeal, and the “possibility of the loss of its claims against Dravo” on statute-of-limitation-24- grounds. The mere possibility of lost claims not even mentioned to the district court falls far short of demonstrating the distri ct court abused its discretion in denying Morrison leave to amend. See Stafford v. Ford Motor Co. , 790 F.2d 702, 706 (8th Cir. 1986) (reasoning “[t]he district courts ca nnot be expected to consider matters that the parties have not expressly ca lled to their attention”); cf. Adams v. AlliedSignal Gen. Aviation Avionics , 74 F.3d 882, 887-88 (8th Cir. 1996) (holding there was no abuse of discretion in refusing to extend Fe d. R. Civ. P. 4 deadline even though the statute of limitation barred plaintiff’s claims ). The district court did not abuse its discretion in denying Morrison’s motion for leave to amend.

III. CONCLUSION We affirm.

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