The NAM filed an amicus brief 6/5/01 with other organizations challenging a district court ruling that Alcan has joint and several liability under CERCLA for processing waste that is commingled with other wastes, without regard to its benign nature. The brief also argued that CERCLA should not be applied retroactively.In January, the Second Circuit ruled that Alcan could not avoid joint and several liability because its waste was not merely at background levels (since it contained PCBs that are not naturally occurring), and that the harmed caused could not be separated from the overall damage at the cleanup site. The court also ruled that CERCLA may be applied retroactively. The decision makes it harder for companies that contribute only small amounts of materials to a hazardous waste cleanup site to limit their liability for a much larger share of the cleanup costs.