I. SYNOPSIS OF THE CASE THE CITY OWNS AND OPERATES A WASTEWATER TREATMENT FA- CILITY THAT TREATS WASTEWATERS FROM RESIDENTIAL, COMMERCIAL AND INDUSTRIAL SOURCES LOCATED IN TERRE HAUTE, INDIANA. THE PLANT IS OPERATED BY THE BOARD OF PUBLIC WORKS AND SAFETY. THE CITY NOW OPERATES THE PLANT IN VIOLATION OF ITS NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) PERMIT. THE INDIANA STREAM POLLUTION CONTROL BOARD (ISPCB) REISSUED AN NPDES PERMIT NO. IN0025607 (PERMIT) TO THE CITY ON FEBRUARY 5, 1986, AND THE PERMIT BECAME EFFECTIVE ON MARCH 12, 1986. THE PREVIOUS NPDES PERMIT (EXPIRED PERMIT), WHICH EXPIRED ON AUGUST 30, 1984, WAS ISSUED TO THE CITY ON AUGUST 31, 1979, AND AMENDED ON JUNE 9, 1980, TO INCLUDE A COMPLIANCE SCHE- DULE TO DEVELOP A PRETREATMENT PROGRAM. SEE ATTACHMENTS A AND B FOR COPIES OF THE CURRENT PERMIT AND THE EXPIRED PER- MIT. BOTH THE CURRENT PERMIT AND THE EXPIRED PERMIT REQUIRE THE CITY TO OPERATE ALL WASTE COLLECTION, CONTROL, TREATMENT AND DISPOSAL FACILITIES AS EFFICIENTLY AS POSSIBLE AND IN A MANNER THAT WILL MINIMIZE UPSETS AND DISCHARGES OF EXCESSIVE POLLUTANTS. IN ADDITION, BOTH PERMITS, BOTH PERMITS REQUIRE THAT COLLECTED SCREENINGS, SLURRIES, SLUDGES AND OTHER SOL- IDS SHALL BE DISPOSED OF IN SUCH A MANNER AS TO PREVENT EN- TRY OF THESE WASTES INTO NAVIGABLE WATERS. A NEW REQUIRE- MENT WAS ADDED TO THE CURRENT PERMIT