RCRA 7003 ADMINISTRATIVE ORDER ON CONSENT ON SEPTEMBER 28, 2010, REGION 7 FILED A RCRA 7003 ADMINISTRATIVE ORDER ON CONSENT (AOC) WITH MARATHON OIL COMPANY (MARATHON) FOR IMPLEMENTATION OF A CMS AND CMI AT THE FORMER WEST SIDNEY GAS PLANT (WSGP) IN SIDNEY, NEBRASKA. MARATHON OWNS AND OPERATED THE WSGP WHICH WAS OPERATED AS A NATURAL GAS PROCESSING PLANT FROM 1954 UNTIL 1985. PAST OPERATIONS AT THE SITE RESULTED IN GROUNDWATER CONTAMINATION IN AN AQUIFER WHICH IS USED FOR A POTABLE WATER SUPPLY, CROP IRRIGATION AND LIVESTOCK WATERING. SOME OF THE MUNICIPAL WATER SUPPLY WELLS FOR THE CITY OF SIDNEY ARE LOCATED DOWN GRADIENT OF THE IDENTIFIED CONTAMINANT PLUME. THE AOC REQUIRES MARATHON TO PERFORM A CMS AND CMI FOR THE SITE AND IMPLEMENT THE CHOSEN REMEDY TO ADDRESS GROUNDWATER CONTAMINATION AT, AND DOWN GRADIENT, OF THE SITE.