Guam v. United States, 593 U.S. 310

The Ordot Dump on Guam was created by the Navy and later used by Guam; the EPA found environmental hazards and sued Guam under the Clean Water Act (CWA).
In 2004 Guam and the EPA entered a consent decree requiring Guam to pay a penalty and remediate/close the dump; the decree stated Guam’s compliance would be "in full settlement and satisfaction" of the United States’ civil claims as alleged in the CWA complaint.
Thirteen years later Guam sued the United States under CERCLA, asserting (a) a §107(a) cost-recovery claim for response costs and (b) a §113(f)(3)(B) contribution claim against the United States.
The D.C. Circuit held the 2004 CWA consent decree had "resolved Guam’s liability" and therefore triggered a §113(f) contribution claim (which precluded a §107 claim) but that any §113(f) claim was time-barred by the 3-year limitations period.
Guam challenged that ruling to the Supreme Court, arguing a settlement must resolve a CERCLA-specific liability to give rise to a §113(f)(3)(B) contribution right.
The Supreme Court unanimously held §113(f)(3)(B) requires resolution of a CERCLA-specific liability to trigger a CERCLA contribution claim, reversed the D.C. Circuit, and remanded.

Issue	Plaintiff's Argument (Guam)	Defendant's Argument (United States)	Held
Whether §113(f)(3)(B) authorizes contribution only after a settlement resolving CERCLA liability, or also after settlements resolving non-CERCLA environmental liabilities (e.g., under the CWA).	§113(f)(3)(B) requires resolution of a CERCLA-specific liability; a CWA settlement does not trigger CERCLA contribution.	§113(f)(3)(B) should cover settlements of other environmental liabilities that functionally overlap with CERCLA response actions.	Held: §113(f)(3)(B) requires resolution of a CERCLA-specific liability; non‑CERCLA settlements do not trigger CERCLA contribution.

United States v. Atlantic Research Corp., 551 U.S. 128 (2007) (frames contribution as a tool to allocate a predicate common liability)
Northwest Airlines, Inc. v. Transport Workers, 451 U.S. 77 (1981) (no general federal right to contribution outside statutory schemes)
Burlington N. & S. F. R. Co. v. United States, 556 U.S. 599 (2009) (limits on §107 liability and reading CERCLA as a whole)
Cooper Industries, Inc. v. Aviall Services, Inc., 543 U.S. 157 (2004) (interpretation of §113 requires consideration of the whole provision)
Middlesex County Sewerage Authority v. National Sea Clammers Assn., 453 U.S. 1 (1981) (courts should not imply additional remedies beyond statutory text in environmental statutes)
Russello v. United States, 464 U.S. 16 (1983) (canons of statutory construction regarding inclusion/exclusion of language)