CALAVERAS ASBESTOS LTD. (CALAVERAS) OWNS AND OPERATES A MILL, ASBESTOS MINING SITE AND A WASTE DISPOSAL SITE NEAR COPPEROPOLIS, CALIFORNIA. THERE, CALAVERAS MINES ASBESTOS ORE AND TRANSPORTS IT TO THE MILL VIA A COVERED CONVEYOR BELT. AT THE MILL, THE ORE IS PROCESSED TO COMMERCIAL TYPE ASBESTOS. THE ASBESTOS-CONTAINING WASTE IS THEN TRANSPORTED TO THE WASTE SITE VIA ANOTHER CONVEYOR BELT. VISIBLE EMISSIONS TO THE AMBIENT AIR HAVE BEEN OBSERVED IN THE PAST BY U.S. EPA INSPECTORS AT A TRANSFER POINT ON THE ORE PREPARATION CONVEYING SYSTEM. THE MAIN MILL FACILI- TY PROCESSES THE CRUSHED ORE TO COMMERCIAL ASBESTOS. THE MILL UTILIZES A SERIES OF BAGHOUSE COLLECTORS WHICH HAVE BEEN OBSERVED IN VIOLATION ON SEVERAL OCCASIONS, BUT NOT ON RECENT INSPECTIONS. THE BAGHOUSE COLLECTORS ARE NOT THE SUBJECT OF THIS REFERRAL. WASTE FROM THE MILL IS TRANSFERED TO THE DISPOSAL SITE BY MEANS OF A CONVEYOR SYSTEM AND ANY EMISSIONS ARE CONTROLLED BY WATER SPRAYS AND COVERS. IT IS THE EMISSIONS FROM THE WATER SPRAYER BOXES WHICH FORM THE BASIS FOR THIS REFERRAL. ANY VISIBLE EMISSIONS FROM THE MILLING OPERATION OR THE WASTE TRANSPORT OPERATION CONSTITUTE VIOLATIONS OF THE NA- TIONAL EMISSION STANDARD FOR HAZARDOUS AIR POLLUTANTS FOR ASBESTOS (NESHAP). CALIFORNIA AIR RESOURCES BOARD INSPEC- TORS HAVE OBSERVED VISIBLE EMISSIONS OF ASBESTOS FROM ALL TRANSFER POINTS ON THE WASTE TRANSFER CON