THE TUCSON INTERNATIONAL AIRPORT AREA IS LOCATED IN PIMA COUNTY, IN SOUTHEASTERN ARIZONA. IT ENCOMPASSES SEC- TIONS OF SOUTHWEST TUCSON, AS WELL AS ADJOINING LANDS SOUTH OF THE CITY. THE SITE WAS LISTED ON THE NPL ON SEPTEMBER 8, 1983. THE SITE WAS LISTED ON THE NPL BECAUSE OF GROUNDWATER CON- TAMINATION (PRIMARILY TCE). THE ROD WAS SIGNED ON AUGUST 22, 1988. OUR INFORMATION INDICATES THAT THERE ARE THREE DISTINCT PLUMES OF CONTAMINATION IN THE AREA. THE MAIN AREA OF CONTAMINATION HAS BEEN DENOMINATED AREA A. TWO SMALLER PLUMES TO THE EAST OF THE MAIN PLUME HAVE BEEN DENOMINATED AREA B. BASED ON THE REMEDIAL INVESTIGATION, WE HAVE IDENTIFIED 7 PRPS FOR AREA A: U.S. AIR FORCE, HUGHES AIRCRAFT COMPANY, CITY OF TUCSON, TUCSON AIRPORT AUTHORITY, MCDONNELL DOUGLAS. GENERAL DYNAMICS AND THE ARIZONA AIR NATIONAL GUARD. GENERAL NOTICE LETTERS WERE SENT TO THESE PARTIES IN AUGUST AND SEPTEMBER 1987. WE SENT SPECIAL NOTICE LETTERS FOR THE RD/RA ON JULY 11, 1988 AND RECEIVED A JOINT GOOD FAITH OFFER ON SEPTEMBER 8, 1988 FROM ALL OF THE ABOVE- LISTED PARTIES EXCEPT GENERAL DYNAMICS. WE HAVE BEEN NEGOTIATING AND RD/RA CONSENT DECREE WITH THE PRPS SINCE SEPTEMBER 20, 1988. MANY LEGAL ISSUES RE- MAIN UNRESOLVED AT THIS TIME. THE 120-DAY NEGTIATION MORATORIUM WILL END ON NOVEMBER 8, 1988.