SUN CHEMICAL DISCHARGED PH INTO THE MUSKEGON POTW IN VIOLATION OF A LOCAL ORDINANCE BETWEEN 6/88 AND 8/90 (11 VIOLATION OF DAILY MAX) AND IN VIOLATION OF PRETREATMENT STANDARDS, AFTER THEY WENT INOT EFFECT BETWEEN 11/7/90 AND 4/92 (10 VIOLATION OF DAILY MAXIMUM).