THIS IS A RCRA 7003 ORDER (REGIONAL NO. 7003-9-2002-0001) REGARDING PETROLEUM RELEASES FROM TWO GASOLINE STATIONS IN TUBA CITY, ARIZONA. THIS ORDER FOLLOWS UP ON AN EARLIER 1996 ORDER (REGIONAL NO. 7003-09-96-01) WHICH WAS RECORDED IN DOCKET UNDER CASE ID 09-1996-0011. THE PRESENT ORDER DIRECTS THE RESPONDENTS TO INSTALL AND OPERATE EQUIPMENT FOR INTERIM REMEDIAL MEASURES (IRM) AT BOTH GAS STATIONS (THE 1996 ORDER REQUIRED INITIAL CLEAN UP AND ASSESSMENT OF IMMEDIATE CONTAMINATION EMANATING FROM THE SITE). THE GAS STATIONS ARE SITUATED ON THE NAVAJO NATION RESERVA- TION, BUT IT IS NOW KNOWN THAT THE PLUME OF CONTAMINATION EXTENDS INTO HOPI TRIBAL TERRITORY. THE PRESENT ORDER REQUIRES THAT THE RESPONDENTS CONTINUE OPERATING AN EXISTING SUBSURFACE VENTILATION AND VOLATILIZATION SYSTEM (SVVS) AT THE THRIFTWAY GAS STATION AND REQUIRES THE RESPONDENTS TO EXPAND THE SYSTEM ONTO THE SUNSHINE WESTERN GAS STATION. IN SEPTEMBER OF 2000, THRIFTWAY BEGAN OPERATION OF A PILOT SVVS SYSTEM THAT IT HAD VOLUNTARILY INSTALLED AT THE THRIFTWAY GAS STATION. THIS SYSTEM HAS PROVED EFFECTIVE AT REMOVING SIGNIFICANT QUANTITIES OF CONTAMINANTS FROM THE SUBSURFACE. UNDER THE PRESENT ORDER (ISSUED 04/02/2002) THE RESPONDENTS MUST ALSO SUBMIT A WORKPLAN FOR INSTALLATION OF SOME TYPE OF IRM ACROSS THE HIGHWAY FROM THE SUNSHINE WESTERN GAS STATION, AT THE TUBA CITY TRUCK STOP CAFE, WHICH IS LOCATED ON HOPI LAND. THE PRESENT