PACIFIC SOUTHWEST AIRMOTIVE ( PSA ), A WHOLLY OWNED SUBSIDIARY OF USAIR, OPERATES A FACILITY THAT OVERHAULS JET ENGINES. AS PART OF ITS OPERATION IN CONDUCTS METAL FINISHING OPERATIONS. IT DISCHARGES INDUSTRIAL PROCESS WASTEWATER FROM THIS FACILITY TO THE CITY OF SAN DIEGO'S POINT LOMA TREATMENT PLANT. SINCE FEBRUARY 15, 1986, ALL EXISTING METAL FINISHERS THAT DISCHARGE TO SEWAGE TREATMENT PLANTS HAVE BEEN REQUIRED TO COMPLY WITH PRETREATMENT STANDARDS GOVERNING THE CHARACTER OF THEIR INDUSTRIAL WASTEWATER. PSA HAS VIOLATED NUMERICAL CONCENTRATION-BASED LIMITS GOVERNING ITS WASTEWATER QUALITY ON AT LEAST 122 OCCASIONS. THESE REQUIREMENTS ARE SET OUT AT 40 C.F.R. 433.15. PSA HAS VIOLATED A REGULATORY PROHIBITION AGAINST DILUTING ITS WASTESTREAM TO COMPLY WITH THESE NUMERICAL CONCENTRATION- BASED LIMITS. USAIR HAS ANNOUNCED ITS INTENTIONS TO CLOSE PSA'S SAN DIEGO FACILITY THIS YEAR, AND SELL PSA TO AVIALL, INC. AVIALL IS NOT EXPECTED TO CONTINUE PSA'S JET ENGINE OVERHAUL OPERATIONS. REGION 9 IS SEEKING A CONSENT DECREE THAT WILL ASSESS PENALTIES FOR PSA'S PAST VIOLATIONS. NO INJUNCTIVE RELIEF SHOULD BE REQUIRED ASSUMING PSA DOES CEASE ITS REGULATED ACTIVITIES AT THE FACILITY.