FROM 1974-81, HILLSBOROUGH COUNTY, FL, ALLOWED LOCAL BUSINESSES TO DISPOSE OF LIQUID WASTES AT THE FORMER SYDNEY MINE, WITH THE PERMISSION OF THE OWNER, AMERICAN CYANAMID CO. IN THE 1980'S THE COUNTY CLOSED THE OPERATION UNDER STATE SUPERVISION, DISPOSING OF CONTAMINATED SOILS AND TREATING CONTAMINATED GROUNDWATER. EPA LISTED THE SITE IN 1986 BECAUSE OF THE PRESENCE OF VOLATILE ORGANIC COMPOUNDS (VOC'S) IN THE GROUNDWATER. IN 1989, EPA ENTERED A CONSENT ORDER WITH THE COUNTY, UNDER WHICH THE COUNTY AGREED TO PAY $25,000 TOWARD EPA'S COSTS, AND TO TURN OVER THE GROUNDWATER SYSTEM TO EPA. REGION 4 THEN ORDERED FIVE PRPS TO TAKE OVER PUMPING AND TREATING. LATER IN 1989, REGION 4 ISSUED A ROD CALLING FOR ENHANCEMENT AND CONTINUED OPERATION OF THE GROUNDWATER TREATMENT SYSTEM UNTIL CLEANUP STANDARDS WERE REACHED FOR NINE VOCS. IN 1990, AFTER NEGOTIATIONS PROVED UNSUCCESSFUL, THE REGION ORDERED 14 PRPS TO PERFORM THE RD/RA. SIX PARTIES HAVE COMPLIED. THE REFERRAL PROPOSES THAT DOJ PURSUE COSTS FROM FIVE OF THESE PARTIES, INCLUDING THE PAST AND PRESENT OWNERS AND THE MOST SIGNIFICANT GENERATORS, PURSUANT TO SECTION 107 OF CERCLA.