ON 11/19/91, AN SO2 MONITOR IN BLUE ISLAND SHOWED AN SO2 EXCURSION, PEAK VALVE OF 0.238 PPM. STATE IS ISSUING A 9A ENFORCEMENT ACTION. EPA ISSUED A 114 INFORMATION REQUEST ON 11/22/91 WITH A SHORT RESPONSE TIME - 1 DAY FOR SOME QUESTIONS, 10 DAYS FOR BALANCE.