THE H.O.D. LANDFILL OPERATED BETWEEN 1963 & 1984 AND ACCEPTED BOTH NON-HAZARDOUS AND SPECIAL WASTES FOR DISPOSAL ON-SITE. FROM 1984 THROUGH AUGUST 19, 1990, U.S. EPA PERFORMED A NUMBER OF ACTIVITIES AT H.O.D., INCLUDING, BUT NOT LIMITED TO A PRELIMINARY ASSESSMENT, SITE INVESTIGATION AND EXPANDED SITE INVESTIGATION (ESI) THAT WERE CONDUCTED IN CONNECTION WITH LISTING THE SITE ON THE NATIONAL PRIORTIES LIST (NPL). H.O.D WAS PLACED ON THE NPL ON FEBRUARY 21, 1990, ON THE BASIS OF HIGH LEVELS OF TRICHLOROETHENE AND DICHLOROETHENE IN THE GROUND WATER THAT WERE DISCOVERED DURING THE ESI. THE TOTAL OF THE COSTS FOR THESE AND OTHER ACTIVITIES IS $644.661.83. THE MAJORITY OF THE PAST COSTS ARE ATTRIBUTABLE TO THE AGENCY'S ESI THAT BEGAN IN APRIL 1987 AND CONCLUDED ON SEPTEMBER 22, 1989. THE AGENCY HAS NAMED THE FOLLOWING AS DEFENDANTS IN THE PROPOSED COST RECOVERY COMPLAINT: WASTE MANAGEMENT OF ILLINOIS, INC., THE CURRENT OWNER OF SITE AND THE OWNER/OPERATOR AT THE TIME OF DISPOSAL, AND MORTON INTERNATIONAL, INC., OUTBOARD MARINE CORPORATION, INC., AND WELLS MANUFACTURING COMPANY, INC., GENERATORS OF WASTES CONTAINING HAZARDOUS SUBSTANCES THAT, COMBINED, DISPOSED OF 96% OF THE TOTAL KNOWN VOLUME OF WASTE AT H.O.D. IT IS ANTICIPATED THAT COST RECOVERY ACTION WILL BE FILED ON OR BEFORE THE SEPTEMBER 22, 1992 STATUTE OF LIMITATIONS DATE.