TIMET OWNS AND OPERATES A TITANIUM MANUFACTORING FACILITY. IN NOVEMBER 1993 TIMET STARTED UP A CARBON MONOXIDE BURNER TO CONTROL CO EMISSIONS AT THE FACILITY. THE USE OF THE CO BURNER CAUSED AN INCREASE OF SO2 EMMISSIONS OF APPROXIMATELY 500 TPV. TIMET SHOULD HAVE OBTAINED A PSD PERMIT FOR THE INCREASED SO2 EMISSIONS, AND SHOULD HAVE MET AN EMISSION LIMIT ACHIEVED THROUGH BEST AVAILABLE CONTROL TECHNOLOGHY, PRIOR TO START-UP OF THE CO BURNER. REGION 9 SEEKS TO RECOVER A PENALTY FOR TIMET'S FAILURE TO MEET THE BACT EMISSION LIMIT. TIMET RECEIVED A PERMIT ON AUGUST 1, 1997. THE PERMIT SETS A BACT LIMIT, BUT DOES NOT CLEARLY SET A TIME FRAME FOR MEETING THE LIMIT. REGION 9 SEEKS TO REQUIRE IMPLMENTATION OF BACT BY WITHIN A SPECIFIED TIME FRAME. (TIMET IS A SUBSIDIARY OF TITANIUM METALS COPORATION.)