OPINION
We must decide, among other things, whether the City of Colton, California, can recover response costs under the Comprehensive Environmental Response, Compensation, and Liability Act allegedly incurred as a result of perchlorate contamination in its water supply.
I
A
The Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (“CERCLA”) “is a comprehensive statute that grants the President broad power to command government agencies and private parties to clean up hazardous waste sites.”
Key Tronic Corp. v. United States,
To establish a prima facie claim for recovery of response costs under section 107(a), a private-party plaintiff must demonstrate:
(1) the site on which the hazardous substances are contained is a “facility” under CERCLA’s definition of that term, Section 101(9), 42 U.S.C. § 9601(9); (2) a “release” or “threatened release” of any “hazardous substance” from the facility has occurred, 42 U.S.C. § 9607(a)(4); (3) such “release” or *1003 “threatened release” has caused the plaintiff to incur response costs that were “necessary” and “consistent with the national contingency plan,” 42 U.S.C. §§ 9607(a)(4) and (a)(4)(B); and (4) the defendant is within one of four classes of persons subject to the liability provisions of Section 107(a).
Carson Harbor Village, Ltd. v. Unocal Corp.,
Response costs are considered necessary when “an actual and real threat to human health or the environment exist[s].”
Id.
at 871. Response costs are considered consistent with the NCP “if the action, when evaluated as a whole, is in substantial compliance” with it. 40 C.F.R. § 300.700(c)(3)(i). The NCP “specifies procedures for preparing and responding to contaminations and was promulgated by the Environmental Protection Agency (EPA) pursuant to CERCLA § 105.”
Cooper Indus., Inc. v. Aviall Servs., Inc.,
B
The City of Colton (“Colton”) draws its water supply from the Rialto-Colton groundwater basin (“Basin”) in San Bernardino County, California. In 1997, Col-ton began monitoring its municipal supply wells for perchlorate contamination. By 2002, Colton had detected perchlorate in three of its wells in concentrations ranging from about 4 to 10 micrograms per liter (“jjtg/L”). At the time, the California Department of Health Services (“CDHS”), which regulates water quality, had an “advisory action level” for perchlorate of 4 µg/L. CDHS informed Colton that because “the perchlorate action level is an advisory action level, and thus, not enforceable,” the three impacted wells “may continue to be used to supply the system.” Nevertheless, in a closed-session meeting between its City Council and City Attorney, Colton adopted a policy of prohibiting the use of water with perchlorate levels above 4 µg/L. Pursuant to this policy, Colton took the impacted wells out of service and instituted a wellhead treatment program to eliminate the perchlorate in 2003.
C
In 2005, Colton filed suit against numerous entities that had engaged in industrial activities in the Basin over the years, alleging that they caused the release of perchlorate into the groundwater. In its third amended complaint, filed in December 2005, Colton alleged that it had spent $4 million to investigate the contamination and to implement the wellhead treatment program. Colton asserted claims for cost recovery and contribution under CERCLA, 42 U.S.C. §§ 9607(a), 9613(f); a claim for declaratory relief as to liability for future costs under the Declaratory Judgment Act, 28 U.S.C. §§ 2201-2202; and various claims under state law.
Numerous defendants filed a motion for summary judgment, arguing that Colton could not recover its wellhead treatment program costs under CERCLA. 1 In its *1004 opposition, Colton argued that the defendants were liable for not only its wellhead treatment program costs, but also costs associated with a future Basin-wide cleanup estimated to cost between $55 and $75 million. The district court granted summary judgment for the defendants on Colton’s federal claims and declined to exercise supplemental jurisdiction over Col-ton’s state law claims. 2 The district court held that Colton could not recover its costs associated with the wellhead treatment program because it failed to show that such costs were necessary'and consistent with the NCP; furthermore, because Colton could not show that it was entitled to recover any of its past costs, its claim for declaratory relief as to its future costs necessarily failed. Colton timely appealed. 3
II
Colton first seeks reversal of the district court’s summary judgment denying recovery of its past response costs. Colton challenges the district court’s conclusion that the wellhead treatment program was unnecessary because there was no immediate threat to the public health or environment.
See
42 U.S.C. § 9607(a)(4)(B). Colton concedes, however, that it failed to comply with the national contingency plan in its past response action. Because Colton’s concession is a sufficient ground upon which to affirm the summary judgment with respect to past response costs, we decline to review the merits of the district court’s conclusion that such costs were unnecessary.
See Dorsey v. Nat’l Enquirer, Inc.,
Ill
Colton also contends that the district court erred in granting summary judgment denying its claim for declaratory relief as to its future response costs.
A
Before addressing the merits of the claim, we turn to the parties’ various jurisdictional arguments.
1
The parties dispute whether Col-ton’s claim for declaratory relief is ripe. “The constitutional ripeness of a declaratory judgment action depends upon whether
*1005
the facts alleged, under all the circumstances, show that there is a substantial controversy, between parties having adverse legal interests, of sufficient immediacy and reality to warrant the issuance of a declaratory judgment.”
In re Coleman,
In
Wickland Oil Terminals v. Asarco, Inc.,
None of these cases imposed any requirement that a party incur
recoverable-
— i.e., necessary and NCP-compliant— response costs before its claim for declaratory relief is ripe. Indeed, our cases make clear that so long as there has been a release of hazardous substances, and the plaintiff spends some money responding to it, a claim for declaratory relief is ripe for review.
Accord Cal. ex rel. Cal. Dep’t of Toxic Substances Control v. Neville Chem. Co.,
Here, the facts establishing Col-ton’s right to declaratory relief have already occurred because there is no dispute that there is perchlorate contamination of the Basin. Moreover, there is no dispute that Colton has incurred costs in responding to the contamination, and that Colton will incur additional costs in the future. The only dispute is whether Colton is entitled to recover these costs, which goes to the merits, not justiciability. Because this controversy cannot be deemed “remote and hypothetical,”
Wickland Oil,
2
We next turn to the argument that Colton has mooted this appeal by filing a substantially new action in the same district court.
5
“A ease is moot on appeal if no live controversy remains at the time the court of appeals hears the case.”
NASD Dispute Resolution, Inc. v. Judicial Council of State of Cal.,
The defendants argue that Colton has effectively redressed the injury it seeks to remedy with this appeal— namely, the district court’s dismissal of its declaratory relief claim — by filing a new *1006 action seeking the same relief. Therefore, our reinstatement of such claim would be superfluous. However, “[t]here is a recognized defense to a claim of mootness in the appellate context when a party can demonstrate that a lower court’s decision, if allowed to stand, may have collateral consequences adverse to its interests.” Connectu LLC v. Zuckerberg, 522 F.3d 82, 88 (1st Cir.2008). Here, Colton faces a potential statute of limitations bar with respect to its claims against certain defendants, an argument these defendants have pressed in the later-filed action. A reversal by this court could put Colton on better footing with regard to limitations defenses, which “is a collateral consequence of the type that suffices to defuse a claim of mootness.” Id. at 89. We therefore conclude that this appeal is not moot.
3
Finally, we consider whether the district court’s disposal of Colton’s CERCLA past response cost-recovery claims deprived the court of subject matter jurisdiction over the declaratory relief claim. 6
“It is well settled that the Declaratory Judgment Act does not itself confer federal subject matter jurisdiction but merely provides an additional remedy in cases where jurisdiction is otherwise established.”
Staacke v. U.S. Sec’y of Labor,
Here, Colton’s declaratory relief claim is predicated on CERCLA, a federal statute providing a private right of action. Colton’s nonfrivolous assertion of a CERCLA declaratory relief claim is therefore sufficient to confer federal subject matter jurisdiction, regardless of the district court’s conclusion that Colton’s CERCLA past response cost-recovery claims lacked merit.
B
Turning to the merits, we note that the district court held that because it was granting summary judgment on the section 107 cost-recovery claims, “Defendants are entitled to summary judgment in their favor on Plaintiffs ... claim for [declaratory] relief as well.” Colton argues that its failure to incur recoverable response costs in the past has no bearing on whether it will incur such costs in the future. 7 Therefore, Colton contends that it should still be allowed to seek declaratory relief as to liability for its future costs.
Whether a CERCLA plaintiffs failure to establish liability for its past costs necessarily dooms its bid to obtain a declaratory judgment as to liability for its future costs appears to be an issue of first impression in this circuit. Our sister circuits have
*1007
taken divergent approaches to this issue. Some have held or suggested that recoverable past costs are a sine qua non for declaratory relief under CERCLA.
See, e.g., Trimble v. Asarco, Inc.,
1
The text of the Declaratory Judgment Act provides, in relevant part, that “[i]n a ease 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(a). CERCLA also contains a provision for declaratory relief. Section 113(g)(2) provides that in any initial cost-recovery action under section 107, “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).
Although Colton’s complaint referred to the Declaratory Judgment Act rather than CERCLA section 113(g)(2), the latter provision clearly governs this initial cost-recovery action. Because “a precisely drawn, detailed statute preempts more general remedies,”
Hinck v. United States,
The declaratory judgment mandated by section 113(g)(2) pertains to “liability for response costs.” 42 U.S.C. § 9613(g)(2). Such “liability for response costs” must refer to the response costs sought in the initial cost-recovery action, given that the sentence later refers to “any subsequent action or actions to recover further response costs.” Id. (emphases added). Therefore, if a plaintiff successfully establishes liability for the response costs sought in the initial cost-recovery action, it is entitled to a declaratory judgment on present liability that will be binding on future cost-recovery actions.
Here, Colton has failed to establish present liability because of its conceded failure to comply with the NCP but seeks a declaratory judgment on
future
liability. Section 113(g)(2), however, does not provide for such relief. “[I]t is an elemental canon of statutory construction that where a statute expressly provides a particular remedy or remedies, a court must be chary of reading others into it.”
Transam. Mortgage Advisors, Inc. v. Lewis,
2
Colton would have us bypass the initial liability determination to further “CERCLA’s goal of encouraging private parties to clean up hazardous sites.” According to Colton, denying declaratory relief “would discourage private parties from taking future actions to clean up hazardous sites if they failed to comply with the NCP in taking past cleanup actions.” CERCLA’s goal, however, is not simply to encourage private response, but rather to “make the party seeking response costs choose a cost-effective course of action to protect public health and the environment” and to achieve “a CERCLA-quality cleanup.”
Carson Harbor II,
Moreover, awarding declaratory relief before a plaintiff has incurred any recoverable costs would undermine the very purpose of declaratory relief, which is to “economize[ ] on judicial time.”
PMC, Inc. v. Sherwin-Williams Co.,
We conclude that CERCLA’s purposes would be better served by encouraging a plaintiff to come to court only after demonstrating its commitment to comply with the NCP and undertake a CERCLAquality cleanup. Upon establishing liability under section 107, the plaintiff can “obtain reimbursement for [its] initial outlays, as well as a declaration that the responsible party will have continuing liability for the cost of finishing the job.”
Dant & Russell,
IV
Colton also appeals from the dismissal of its pendent state law claims. Having disposed of Colton’s federal claims, the district court declined to exercise supplemental jurisdiction over the state law claims.
See
28 U.S.C. § 1367(c)(3). “Because the district court did not err in granting summary judgment on the federal claims, it did not abuse its discretion in dismissing the state-law claims.”
Bryant v. Adventist Health Sys./W.,
V
For the foregoing reasons, the district court’s summary judgment is AF *1009 FIRMED. 8
Notes
. The defendant entities which joined in the motion were the County of San Bernardino, the 1996 Thomas O. Peters and Kathleen S. *1004 Peters Revocable Trust, Thomas O. Peters, American Promotional Events, Inc.-West, Pyro Spectaculars, Inc., Astro Pyrotechnics, Inc., Emhart Industries, Inc., Kwikset Locks, Inc., Black & Decker, Inc., Whittaker Corp., and Trojan Fireworks Co.
. Although not all the defendants joined in the motion for summary judgment, the district court sua sponte granted summary judgment in favor of the non-moving defendants.
. The district court also dismissed all counterclaims and cross-claims. Both Goodrich and Pyro Spectaculars, Inc. cross-appealed from the district court's dismissal of these counterclaims and cross-claims. We address the cross-appeals in a memorandum disposition filed concurrently with this opinion.
. Colton contends that if the district court’s holding on the necessity of the response action is allowed to stand, such holding could have a preclusive effect in subsequent litigation. We note, however, that in a future action, Colton could argue that our reliance on the NCP compliance holding alone vitiates any preclusive effect of the district court's necessity holding.
See, e.g., Niagara Mohawk Power Corp. v. Tonawanda Band of Seneca Indians,
. The second action filed by Colton, No. 06-01319, was eventually dismissed without prejudice. Colton then filed a third action, No. 09-01864, which is currently pending in the district court. It is this third action to which we refer.
. We reject the argument that Colton is judicially estopped from arguing that there is subject matter jurisdiction. It is well established that subject matter jurisdiction cannot be expanded or contracted "by prior action or consent of the parties.”
Am. Fire & Cas. Co. v. Finn,
. Contrary to the defendants’ assertion, Col-ton did not waive this argument by failing to raise it below. In opposition to summary judgment, Colton argued that "it was not required to complete all tasks required by the NCP prior to the filing of the complaint,” and that "so long as [it] has incurred at least nominal response costs,” it could "invoke the declaratory relief provision of CERCLA to recover its future costs,” even if "it is still too early to know how Colton will comply with the NCP.” This is the same argument it now makes on appeal.
. We grant the outstanding motions for judicial notice.
