Editors' Summary: When Congress passed CERCLA, it chose to omit specific reference to joint and several liability in the statute, intending courts to determine the scope of liability on a case-by-case basis. Since then, courts have applied common-law principles, set forth in the Restatement (Second) of Torts, to cases involving multiple defendants responsible for contamination at CERCLA sites. These principles call for imposition of joint and several liability on multiple tortfeasors unless the harm is divisible or there is a reasonable basis for apportionment. Two recent decisions by the U.S. Courts of Appeals for the Second and Third Circuits, both captioned United States v. Alcan Aluminum Corp., may provide some relief to CERCLA defendants seeking to escape joint and several liability. The Third Circuit held that divisibility of harm should be determined at the initial liability phase of a case, affording CERCLA defendants an opportunity to obtain an earlier determination of their liability and reduce their litigation costs. The Second Circuit held that although CERCLA does not require plaintiffs to prove causation, defendants who prove that their pollutants do not exceed background levels or thresholds established by EPA may escape liability.

The authors examine the development of CERCLA case law addressing joint and several liability as background to understanding the two Alcan decisions. They then analyze the decisions and their implications. They suggest how defendants may use the decisions in attempting to limit or avoid CERCLA liability and conclude that the CERCLA defendants who will benefit most from these decisions will be those who are active in the administrative process for establishing hazardous substance thresholds and who use experts effectively to prove divisibility of harm.