The typical case arising under the Comprehensive Environmental Response, Compensation, and Liability Act\u27 (CERCLA) involves hazardous waste generation and disposal spanning several decades by companies no longer in existence. Subsequent attempts at cleanup by federal and state governments and private parties, as well as legal battles over the ultimate responsibility, are also at issue in the typical CERCLA case. A single party is rarely responsible for the toxic waste pollution of a site. Usually, a toxic waste site, such as a landfill, will have numerous potentially responsible parties (PRPs): generators;transporters; current owners and their lessees; former owners and operators and their successor corporations; individual corporate officers; and even governmental agencies. Ideally, the liability of each PRP would equal its proportionate share of the cleanup costs
