LENZ OIL SERVICES, INC., WHICH IS NOW DEFUNCT, OPERATED A WASTE OIL AND SOLVENT RECYCLING, STORAGE AND TRANSFER FACILI TY FROM APPROXIMATELY 1961 TO 1985. THE LENZ OIL SITE IS LOCATED IN AN UNINCORPORATED AREA OF SOUTHWEST DU PAGE COUNTY, APPROXIMATELY TWO MILES NORTHEAST OF THE VILLAGE OF LEMONT, ILLINOIS, TWO MILES SOUTH OF THE VILLAGE OF BURR RIDGE, ILLINOIS, AND ONE MILE EAST OF ARGONNE NATIONAL LABORATORY. THE FACILITY PROPERTY WEHRE LENZ OPERATED IS BOUNDED BY JEANS ROAD TO THE SOUTH, ROUTE 83 TO THE WEST, OPEN LAND TO THE EAST, AND THE ATCHISON, TOPEKA, AND SANTA FE RAILROAD TO THE NORTH. THE LENZ OIL SITE CONSISTS OF THE LENZ OIL FACILITY PROPERTY AND CONTIGUOUS PROPERTY CONTAIN- ING CONTAMINATION ORGINATING FROM THE LENZ OIL PROPERTY. CURRENTLY, SHALLOW AQUIFER CONTAMINATION EXTENDS FROM THE LENZ OIL PROPERTY'S SOUTHERN EDGE SOUTH TO APPROXIMATELY 250 FEET SOUTH OF JEAN ROAD, COVERING AN AREA OF APPROXIMATELY 1.5 ACRES. APPROXIMATELY 400 FEET FURTHER SOUTHEAST IS THE CLOSEST SIGNIFICANT SURFACE WATER BODY, THE DES PLAINES RIVER. RECORDS INDICATE THAT A SIGNIFICANT PORTION OF THE LENZ OIL SITE IS PART OF THE DES PLAINES RIVER'S 100-YEAR FLOOD PLAIN. THERE ARE ALSO THREE ISOLATED SOIL CONTAMINA- TION AREAS: (1) A DITCH ALONG THE NORTHERN EDGE OF THE FACI- LITY, (2) SOILS SURROUNDING A MONITORING WELL WITHIN THE EMERGENCY RESPONSE EXCAVATION AREA, AND (3) SOILS ALONG THE SOUTHERN EDGE OF THE PROPERTY.