Written by Jeffrey Karp, Environment, Energy and Natural Resources Group Leader, and Edward Mahaffey, law clerk.
Liability for clean-up of hazardous substances pursuant to the Comprehensive Response, Compensation and Liability Act of 1980 ("CERCLA," "Act" or "Superfund") can be extremely costly, amounting to hundreds of millions of dollars. Under CERCLA’s broad liability net, the United States Environmental Protection Agency ("EPA") can obtain reimbursement of response costs from or require potentially responsible parties ("PRPs") to conduct response actions to address releases or threatened releases of hazardous substances from a facility. See 42 U.S.C. § 9607(a); 42 U.S.C. § 9601(9)(B).
Although CERCLA does not specify the liability standard in government cost recovery cases under Section 107, most courts have accepted the application of strict, joint and several liability for PRPs who cannot prove divisibility of the harm they caused from the total harm. See O’Neil v. Picillo, 883 F.2d 176, 178-79 (1st Cir. 1989) ("The rule adopted by the majority of courts, and the one we adopt, is based on the Restatement (Second) of Torts: damages should be apportioned only if the defendant can demonstrate that the harm is divisible."). In Burlington Northern & Santa Fe Railway Co. v. United States, 556 U.S. 599 (2009), the U.S. Supreme Court recognized apportionment as a judicially created affirmative defense to joint and several liability under CERCLA. It instructed the lower courts to follow the Restatement (Second) of Torts § 433A in determining whether harm is divisible in any specific case, which occurs when "there is a reasonable basis for determining the contribution of each cause to a single harm." 556 U.S. at 614. The burden of proof, however, is placed on defendants to establish that such a reasonable basis exists. See Restatement (Second) of Torts § 433B(2); Burlington Northern at 617 (there must be "facts contained in the record reasonably support[ing] the apportionment of liability."). The practical effect of placing the burden on defendants to prove divisibility is that responsible parties rarely escape joint and several liability, which means that any one PRP may be held responsible for the entire cost of a cleanup. See Guam v. U.S., 950 F.3d 104, 107 (D.C. Cir. 2020).