potentially responsible party (PRP) これかな？
Potentially Responsible Parties are individuals, companies, or any other parties that are potentially liable for payment of Superfund cleanup costs. Companies that generate hazardous substances disposed of at a Superfund site, current and former owners and operators of the site, and transporters who selected the site for disposal of hazardous substances may be responsible for part or all of the cleanup costs.
EPA attempts to identify PRPs early to achieve a PRP-lead cleanup rather than EPA performing a Superfund (Fund-lead) cleanup. A PRP search generally is initiated around the time of site discovery. EPA conducts a preliminary search to identify obvious PRPs. PRP searches include reviewing state and federal agency records, conducting title searches, interviewing site operators, and performing PRP financial assessments.
If a PRP having sufficient financial assets is unwilling to settle, EPA may issue a unilateral administrative order (UAO) under Section 106(a) of CERCLA. A UAO compels the party to conduct the cleanup. Failure to comply with a UAO may result in the imposition of fines, damages, and court orders to conduct the cleanups. If EPA feels the site requires immediate action, EPA uses Superfund monies to proceed with cleanup (a Fund-financed cleanup), with the authority to later recover its costs from PRPs through Administrative actions, if less than $500,000. When more than $500,000 is sought, EPA must go to court to recover its expenses. These lawsuits usually result in a settlement (consent decree), but may go to full trial.