ROHM AND HAAS KENTUCKY, INC. OPERATES A SPECIALITY CHEMICAL PROCESSING PLANT LOCATED IN LOUISVILLE, KY. IT PRODUCES BY- PRODUCTS OF PLASTIC ADDITIVES, INCLUDING EMULSIONS, RESINS, MOLDING POWDER AND PELLETS, PLEXIGLAS, AND ACRYLIC COATING. THE PLANT USES THREE COAL-FIRED BOILERS TO SUPPLY ITS RE- QUIREMENTS FOR STEAM AND TO SELL STEAM TO NEIGHBORING FACI- LITIES. ROHM AND HAAS LEASED A RECONSTRUCTED NATURAL GAS STEAM GENERATING BOILER TO PRODUCE STEAM DURING MAINTENANCE OUTAGES OF ITS THREE EXISTING BOILERS. IT OPERATED THE BOI- LER FROM SEPTEMBER 1989 TO JUNE 1991. THE COMBUSTION OF NATURAL GAS IN BOILERS RESULTS IN EMISSION OF NITROGEN OXIDES, A FEDERALLY REGULATED AIR POLLUTANT. THE BOILERS WHICH EMIT NITROGEN OXIDES ARE SUBJECT TO THE PROVI- SIONS OF SECTION 111 OF THE CLEAN AIR ACT (CAA) 42 U.S.C. S 7411, AND 40 C.F.R. PART 60. IN ADDITON, THE RECONSTRUCTED INDUSTRIAL BOILER THAT WAS LEASED BY ROHM AND HAAS WAS SUB- JECT TO SUBPARTS A AND DB OF 40 C.F.R. PART 60. THE PROVIS- IONS PROMULGATE STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES OF AIR POLLUTANTS, AND ARE REFERRED TO AS NEW SOURCE PERFORMANCE STANDARDS (NSPS). ROHM AND HAAS VIOLATED THE NSPS PROVISIONS WHEN IT FAILED TO CONDUCT AN INITIAL PERFORMANCE TEST OF THE LEASED BOILER IN A TIMELY MANNER, AND FAILED TO INSTALL, CALIBRATE, MAIN- TAIN, AND OPERATE A CONTINOUS MONITORING SYSTEM FOR MEASUR- ING EMISSIONS OF NITROGEN OXIDES IN