ASARCO v. Union Pacific Railroad Company, 762 F.3d 744

ASARCO operated a large lead smelter in Omaha for over a century; soil and blood-lead testing revealed widespread contamination and health risks.
EPA designated ~27 square miles around the smelter a Superfund site and sued; ASARCO settled its CERCLA liability for about $214 million in bankruptcy proceedings.
Union Pacific (UP) owned the smelter land early on and was named a potentially responsible party; UP litigated FOIA requests against the EPA and obtained materials that reduced ASARCO’s payment by $15 million.
To facilitate ASARCO’s participation in the FOIA litigation, ASARCO and UP signed a Tolling Agreement extending contribution-related statutes of limitation for two years and expressly reserving "all rights and defenses" except the tolled limitations period.
UP then settled its CERCLA exposure with the EPA for $25 million via a judicially approved consent decree that—under CERCLA § 113(f)(2)—bars contribution claims "regarding matters addressed in the settlement." ASARCO received notice but did not object or intervene before entry of the decree.
ASARCO later sued UP for breach of the Tolling Agreement, contribution, and declaratory relief; the district court dismissed, holding the consent decree precluded ASARCO’s claims and UP had not waived or breached the Tolling Agreement.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether CERCLA § 9613(f)(2) and the consent decree bar ASARCO’s contribution/indemnity claims	ASARCO: UP’s settlement cannot extinguish ASARCO’s contribution rights because the Tolling Agreement preserved ASARCO’s claims	UP: The consent decree shields UP from contribution claims "regarding matters addressed in the settlement" and thus bars ASARCO’s suit	Held for UP: The consent decree and § 9613(f)(2) bar ASARCO’s contribution claims related to site remediation
Whether UP waived or breached the Tolling Agreement by obtaining contribution protection	ASARCO: Tolling Agreement preserved contribution claims "unaltered" and UP breached by settling	UP: Tolling Agreement only tolled the statute of limitations and expressly reserved all other rights and defenses; UP acquired statutory protection later	Held for UP: Under Nebraska law, no waiver—UP had no "known, existing" right at signing and Tolling Agreement did not clearly and unequivocally waive future CERCLA protection
Whether UP is estopped from invoking contribution protection	ASARCO: UP’s communications and conduct could estop UP from asserting the defense	UP: Estoppel not pleaded or argued below; no basis presented to district court	Held for UP: Appellate court declined to reach estoppel because ASARCO forfeited that theory by failing to raise it in district court

Union Pac. R.R. v. Dep’t of Homeland Sec., 738 F.3d 885 (8th Cir. 2013) (standard for statutory/contract interpretation)
Control Data Corp. v. S.C.S.C. Corp., 53 F.3d 930 (8th Cir. 1995) (discussing joint-and-several CERCLA liability and allocation challenges)
United States v. BP Amoco Oil PLC, 277 F.3d 1012 (8th Cir. 2002) (policy favoring settlements under CERCLA)
United States v. Davis, 261 F.3d 1 (1st Cir. 2001) (holding contribution protection covers costs addressed in settlement)
United States v. Se. Penn. Transp. Auth., 235 F.3d 817 (3d Cir. 2000) (similar holding on scope of matters addressed in settlement)
Axel Johnson, Inc. v. Carroll Carolina Oil Co., 191 F.3d 409 (4th Cir. 1999) (settlement can moot pending contribution litigation)
Lion Oil Co. v. Tosco Corp., 90 F.3d 268 (8th Cir. 1996) (incorporating state-law principles in CERCLA-related private allocation disputes)
Aetna Cas. & Sur. Co. v. Gen. Dynamics Corp., 968 F.2d 707 (8th Cir. 1992) (insurance/indemnity issues under CERCLA context)
Village of Memphis v. Frahm, 843 N.W.2d 608 (Neb. 2014) (Nebraska decision recognizing that broadly worded waivers can include unknown claims)