In two major Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) opinions, United States v. Atlantic Research, Inc. and Burlington Northern & Santa Fe R.R. v. United States, the U.S. Supreme Court provided long-sought guidance for parties litigating hazardous waste cleanup issues under CERCLA.

On May 4, 2009, the U.S. Supreme Court handed down its decision in Burlington Northern & Santa Fe Railway Co. v. United States. The decision is of major significance with respect to two areas of Superfund jurisprudence--"arranger" liability, and divisibility or apportionment of harm. This Article is concerned only with the latter issue and, moreover, only with one specific element of that issue.

This past May, the U.S. Supreme Court for the first time addressed two issues that the U.S. Congress left open in the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). These issues are: (1) the scope of "generator" or "arranger" liability under the language of CERCLA §107(a)(3); and (2) the circumstances under which a liable party under §1073 may be held jointly and severally liable. Rejecting the position of the U.S.