UNDER THIS ADMINISTRATIVE CONSENT ORDER, MOBIL IS INSTALLING A MONITORING AND ALARM SYSTEM ON THE CARBON MONOXIDE BOILER SYSTEM AT THE FLUID CATALYTIC CRACKING UNIT, TO ALERT MOBIL STAFF OF A FCCU EXHAUST GAS LEAK THROUGH THE CO BOILER BY- PASS VALVE, THUS BYPASSING THE CO BOILERS. THE CO VIOLATION DETECTED IN 1995 WAS DUE TO SUCH A LEAK. EPA INITIALLY ISSUED A DRAFT ORDER FOR INSTALLATION OF A CONTINUOUS EMISSIONS MONITOR FOR CO, BUT MOBIL CONDUCTED A STUDY INTEND ED TO DEMONSTRATE THAT EXHAUST GAS TEMPERATURE DOWNSTREAM FROM THE BYPASS VALVE WOULD INDICATE THE PRESENCE OF A LEAK. INSTALLATION OF A TEMPERATURE MONITOR AND ALARM SYSTEM, SET FORTH IN THIS ADMINISTRATIVE CONSENT ORDER, WILL ALLOW MOBIL TO IDENTIFY AND ADDRESS A LEAK THROUGH THE BYPASS VALVE BEFORE AN EXCEEDANCE OF THE CO LIMIT OCCURS. THE ORDER ALSO SETS FORTH RECORDKEEPING AND REPORTING REQUIRE- MENTS SUCH THAT EPA WILL BE AWARE OF ANY LEAK SITUATIONS AND CAN ADDRESS POTENTIAL EXCEEDANCES OF THE CO LIMIT. THUS, THE ENVIRONMENTAL BENEFIT OF THIS ORDER LIES IN THE PREVEN- TION OF EXCESS CO EMISSIONS TO THE ATMOSPHERE. NOTE: AN ADMINISTRATIVE PENALTY ORDER FOR THE VIOLATIONS WAS ISSUED TO MOBIL IN JANUARY 1997. (05-1996-0320)