ON OCTOBER 25, 1990, A STACK COMPLIANCE TEST OF THE CSHB BAGHOUSE SHOWED VIOLATINS OF PERMITTED PARTICULATE AND LEAD EMISSION LIMITS. ASARCO REPORTED THE VIOLATIONS JANUARY 15, 1991, AND THEN REQUESTED A MODIFICATION TO THE PERMIT DUE TO STRINGENT LIMITS. IN JUNE, A SECOND COMPLIANCE TEST WAS DONE AND THE EMISSIONS WERE IN COMPLIANCE. ASARCO HAD AN IN HOUSE EXPERT COME IN AND DETERMINE THAT THE EMISSION EXCEEDANCE WAS DUE TO MALFUNCTIONS IN THE EQUIPMENT THAT COULD EASILY BE FIXED.