BOHEMIA INC. (BOHEMIA) OPERATES TWO WOOD-WASTE FIRED BOILERS (BOILERS #1 AND #2) AT ITS LUMBER MILL AT LINCOLN, CALIFORNIA. BOTH BOILERS ARE SUBJECT TO PREVENTION OF SIGNIFICANT DETERIORATION (PSD) REQUIREMENTS AND BOILER #2 IS SUBJECT TO NEW SOURCE PERFORMANCE STANDARDS (NSPS) REQUIREMENTS. BOHEMIA HAS VIOLATED PROVISIONS OF BOTH THE PSD AND NSPS REGULATIONS IN THE CONSTRUCTION AND OPERATION OF THE BOILERS. IN 1984 BOHEMIA CONSTRUCTED BOILER #1. AT THE TIME OF CONSTRUCTION, IT WAS NOT SUBJECT TO PSD REVIEW BECAUSE BOHEMIA HAD OBTAINED FEDERALLY ENFORCEABLE LIMITATIONS IN A PLACER COUNTY AIR POLLUTION CONTROL DISTRICT (PCAPCD) CONSTRUCTION PERMIT. THOSE EMISSION LIMITS RESTRICTED BOILER #1'S EMISSIONS TO LEVELS BELOW THE PSD APPLICABILITY THRESHOLD. HOWEVER, IN 1985 BOHEMIA OBTAINED AN INCREASED EMISSION LIMIT IN ITS DISTRICT PERMIT FOR BOILER #1. THE INCREASED LIMITS IN THE DISTRICT PERMIT, AS CONFIRMED BY A 1985 SOURCE TEST, MADE BOILER #1 SUBJECT TO PSD REVIEW. BOHEMIA THEN CONSTRUCTED BOILER #2 IN 1986. BOILER #2 IS SUBJECT TO PSD REVIEW AS A MAJOR MODIFICATION TO A MAJOR SOURCE (BOILER #1). BOTH BOILERS ARE OPERATING WITHOUT A PSD PERMIT, IN VIOLATION OF THE PSD REGULATIONS. ON JUNE 13, 1988, EPA SENT BOHEMIA A NOTICE OF VIOLATIO N (NOV) STATING THAT BOHEMIA WAS IN VIOLATION OF THE CLEAN AIR ACT BECAUSE IT HAD CONSTRUCTED A MAJO