THE OAK GROVE SANITARY LANDFILL (OGSL) BEGAN RECEIVING WASTE IN 1967 AND CONTINUED UNTIL 1984 WHEN THE LANDFILL REACHED CAPACITY. WHILE MOST OF THE WASTE RECEIVED AT THE LANDFILL CONSTITUTED HOUSEHOLD TRASH, A CERTAIN QUANTITY OF INDUSTRI- AL, CHEMICAL AND HAZARDOUS WASTE IS BELIEVED TO BE BURIED IN THE CENTER OF THE OGSL. MANY ORGANIC COMPOUNDS WERE DE- TECTED IN GROUNDWATER, SURFACE SOIL AND LEACHATE SAMPLES COLLECTED BY U.S.EPA AT THE SITE. - REMEDIATION FOR THE OGSL WAS DIVIDED INTO 2 OPERABLE UNITS, THE FIRST OF WHICH ADDRESSES THE SOURCE OF CONTAMINATION BY CONTAINING ON SITE WASTES AND CONTAMINATED SOILS. THE 2ND OPERABLE UNIT ADDRESSES GROUNDWATER CONTAMINATION VIA NATURAL ATTENUATION AND INSTITUTIONAL CONTROLS. THE REMEDI- AL INVESTIGATIONS AND FEASIBILITY STUDIES (RI/FS) FOR THESE OPERABLE UNITS WERE CONDUCTED BY THE MINNESOTA POLLUTION CONTROL AGENCY. - RECORDS OF DECISION FOR OPERABLE UNITS 1 & 2 WERE SIGNED ON 9/30/88 AND 12/21/90, RESPECTIVELY. - THERE ARE SIGNIFICANT PAST COSTS ASSOCIATED WITH THE SITE. U.S. EPA PLANS TO SEND OVER 80 SPECIAL NOTICE LETTERS TO PARTIES IT BELIEVES RESPONSIBLE FOR THE CONTAMINATION ON 2/15/90. A 120 DAY PERIOD OF RD/RA