USEPA FILED THE COMPLAINT IN THIS MATTER ON 4/12/90, ALLEGING IN 2 COUNTS THAT MURPHY OIL HAD VIOLATED 40 CFR SECTIONS 761.30(D) AND 761.40(A) BY FAILING TO REDUCE THE PCB CONCENTRATION IN ITS HEAT TRANSFER SYSTEM TO LESS THAT 50 PARTS PER MILLION BY 7/1/84, BY FAILING TO TEST ITS HEAT TRANSFER SYSTEM FOR PCBS, AND BY FAILING TO PROPERLY MARK ITS HEAT TRANSFER SYSTEM. THE MONSANTO COMPANY HAD FLUSHED THE PCBS FROM MURPHY OIL'S HEAT TRANSFER SYSTEM IN 1972 AND, THEREFORE, MURPHY OIL BELIEVED THAT THERE WERE NO PCBS PRESENT AT ITS FACILITY. AFTER USEPA FILED ITS COMPLAINT, MURPHY OIL INVESTIGATED OTHER AREAS OF THE FACILITY AND FOUND THAT THERE WAS EXTENSIVE PCB CONTAMINATION OF, AMONG OTHER THINGS, SOILS AND BUILDINGS. CONSEQUENTLY, AT A COST EXCEEDING $1,000,000, MURPHY OIL COMPLETED A COMPREHENSIVE CLEANUP OF PCB CONTAMINATION AT ITS RHINELANDER, WI FACILITY.