10/9/01: GROUND WATER CONTAMINATION WAS FIRST DETECTED IN H ASTINGS, NEBRASKA IN DECEMBER 1983, WHEN CITIZENS COMPLAINED ABOUT THEIR DRINKING WATER. THE CITY REQUESTED ASSISTANCE FROM THE STATE OF NEBRASKA TO INVESTIGATE A POTENTIAL HEALTH THREAT. THE NEBRASKA DEPARTMENT OF HEALTH ANALYZED SAMPLES COLLECTED FROM CITY SUPPLY WELLS AND FOUND THAT ONE OF THE CITY SUPPLY WELLS, M-18, WAS CONTAMINATED WITH TRICHLOROETHY LENE ( TCE ). M-18 WAS IMMEDIATELY DECOMMISSIONED AND FURTH ER SAMPLING UNDERTAKEN. EPA WAS NOTIFIED AND BEGAN ITS INVE STIGATION IN 1984. IN APRIL, 1985, THE NEBRASKA DEPARTMENT OF ENVIRONMENTAL CONTROL ( NDEQ ) REQUESTED EPA TO TAKE LEAD ACTION AT THE HASTINGS SITE. DUE TO THE HIGH LEVELS OF VOL ATILE ORGANIC COMPOUNDS ( VOCS ) FOUND IN THREE MUNICIPAL WE LLS, EPA DESIGNATED THE CONTAMINATED AREA AS THE HASTINGS GR OUND WATER CONTAMINATION SITE. THE SITE COVERS THE CENTRAL INDUSTRIAL AREA OF THE CITY OF H ASTINGS AND ADJACENT AREAS OUTSIDE OF THE CITY LIMITS. THE SITE WAS PLACED ON THE NATIONAL PRIORITIES LIST IN 1986. EPA INITIALLY ADDRESSED T HE SITE AS A SINGLE ENTITY AND ANTICIPATED A COMPREHENSIVE R ESPONSE ACTION WOULD REMEDIATE THE SITE. AS THE SITE INVEST IGATIONS EVOLVED, INCLUDING AN EXTENSIVE GROUND WATER MONITO RING PROGRAM, IT BECAME APPARENT THAT THE SITE WOULD REQUIRE THE DESIGNATION OF SEVERAL SUBSITES AND OPERABLE UNITS TO A DDRESS THE INDIVIDUAL SOURCES OF CON