1. THIS ENFORCEMENT ACTION ASKS FOR A CIVIL PENALTY AND INJUNCTIVE RELIEF. DEFENDANT OPERATES AT HIS FACILITY PERLITE AND VERMICULITE CALCINERS SUBJECT TO NEW SOURCE PERFORMANCE STANDARDS ( NSPS )--CAA PARA 111, 40 C.F.R. PART 60, SUBPART UUU. DEFENDANT FAILED TO PROVIDE NOTIFICATIONS, FAILED TO CONDUCT INITIAL PERFORMANCE TESTS, AND FAILED TO MEET THE APPLICABLE NSPS PARTICULATE MATTER EMMISSION LIMIT FOR THE CALCINERS. 2. THERM-O-ROCK WEST, INC. PRIVATE FAMILY-HELD COMPANY PRODUCES PERLITE AND VERMICULITE (USED FOR INSULATION IN BUILDING MATERIALS) 3. DEFENDANT USES BAGHOUSES TO CONTROL PARTICULATE MATTER EMISSIONS FROM THE AFFECTED CALCINERS. DEFENDANT WILL BE REQUIRED TO UPGRADE AND PROPERLY OPERATE THE BAGHOUSES SO THAT CALCINERS COMPLY WITH THE APPLICABLE NSPS EMISSION LIMIT. 4. THIS ACTION IS NOT PRECEDENTIAL OR NATIONALLY SIGNIFICANT. FACILITY IS LOCATED ON THE GILA RIVER INDIAN RESERVATION IN MARICOPA COUNTY, ARIZONA.