ARMCO'S MANSFIELD, OHIO FACILITY IS A SECONDARY STEEL PLANT THAT PRODUCES STEEL IN ELECTRIC ARC FURNACES FROM SCRAP STEEL AND METAL ALLOY ADDITIONS. THE FACILITY HAS BEEN USED TO MANUFACTURE STEEL SINCE THE EARLY PART OF THIS CENTURY. EPA REGION 5 HAS INFORMATION THAT HAZARDOUS WASTES AS DE- FINED IN RCRA SECTION 1004(5) ARE PRESENT AT THE FACILITY IN CONNECTION WITH THE FOLLOWING UNITS: THE LOCATION OF AN OLD COKE PILE; A PROCESSING AREA FOR SLAG GENERATED BY THE FACILITY'S ELECTRIC ARC FURNACES; AN OLD LANDFILL )CLOSED 1979) IN WHICH ELECTRIC ARC FURNACE DUST WAS LANDFILLED FOR MANY YEARS; THE RAVINE BETWEEN THE SLAG PROCESSING AREA AND THE LANDFILL; A SPENT PICKLY LIQUOR RECOVERY AREA; AND A DEEP INJECTION WELL IN WHICH 11 MILLION GALLONS OF SPENT PICKLE LIQUOR WERE DISPOSED BETWEEN 1968 AND 1971. EPA HAS DETERMINED THAT THE PRESENCE OF HAZARDOUS WASTES AT THE FACILITY MAY PRESENT A SUBSTANTIAL HAZARD TO HUMAN HEALTH OR THE ENVIRONMENT. THE ORDER REQUIRES ARMCO (1) TO COLLECT AND ANALYZE SOIL AND SEDIMENT SAMPLES TO DETERMINE THE NATURE AND EXTENT OF CONTAMINATION IN CONNECTION WITH THE UNITS DESCRIBED ABOVE; (2) TO DETERMINE THE NATURE AND EXTENT OF CONTAMINATED LEACHATE DISCHARGED TO ROCKY FORK CREEK IN CONNECTION WITH THESE UNITS; (3) TO CHARACTERIZE THE HYDROGEOLOGY UNDER THE FACILITY; AND (4) TO DETERMINE THE NATURE AND EXTENT OF CONTAMINATION IN THE GROUNDWATER AT