URBAN BUS REBUILD CAS DISCOVERED DURING AN EPA AUDIT. THREE BUSES WERE FOUND TO BE REBUILT WITHOUT NECESSARY CERTIFIED UPGRADE EQUIPMENT. RESPONDENT HAS SINCE INSTALLED THE EQUIPMENT ON THESE THREE BUSES, PLUS SEVEN OTHERS WHICH DIDN'T LEGALLY REQUIRE IT. RESPONDENT HAS AGREED TO CONDUCT A SELF-AUDIT PROGRAM TO DETERMINE COMPLIANCE FOR THE NEXT THREE YEARS, AND TO REPORT THE RESULTS TO EPA.