When expending Superfund monies at a CERCLA (Comprehensive Environmental Response, Compensation and Liability Act) site, EPA must conduct a search to identify parties with potential financial responsibility for remediation of uncontrolled hazardous waste sites. EPA regional Superfund Waste Management Staff issue a notice letter to the potentially responsible party (PRP). Data from this notice letter is used to form the Site Enforcement Tracking System (SETS). This data includes PRP name and address, a company contact person, the date the notice was issued, and the related CERCLA site name and identification number. SETS was created by EPA to track PRP identification at both NPL (National Priority List) and non-NPL sites. SETS does not address the range of other administrative duties related to tracking the PRP. These lists represent EPA's preliminary findings on the identities of PRPs. Inclusion on these lists does not constitute a final determination concerning the liability of any party for the hazard or contamination at any CERCLA site.