The United States seeks in its Complaint, among other things: the performance of a removal action at the former Rogers Cartage Site and the reimbursement of costs incurred and to be incurred by EPA. Beginning in the 1950s through Apri1 30, 1970, a predecessor of the Settling Defendant leased the approximately five-acre parcel in the southern portion of the East St. Louis Terminal that encompasses the Site to Rogers Cartage Company. Based on testimonial evidence of former employees of the Rogers Cartage Company and others, the Rogers Cartage Company hauled hazardous substances, including PCBs, in tanker trucks and washed the trucks at the Site. The evidence indicates that the Rogers Cartage Company washed chemical residue out of tankers into low-lying areas on the Site that have since been backfilled to grade. Based on the investigations and the results of prior sampling, the highest concentrations of PCBs detected at the Site axe in these areas.