THE NORTHEAST OHIO REGIONAL SEWER DISTRICT HAD CONSTRUCTED A WASTEWATER TREATMENT PLANT USING A RELATIVELY UNTESTED PHYSICAL-CEHMICAL PROCESS. BECAUSE OF REPEATED FAILURES OF THE SYSTEM, THE DISTRICT EXPERIENCED NUMEROUS VIOLATIONS OF ITS NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM ( NPDES PERMIT. AFTER REPEATED ATTEMPTS TO RESOLVE THE PROBLEMS WITH THE SYSTEM, THE DISTRICT DECIDED TO REPLACE IT WITH A BIOLOGICAL TREATMENT SYSTEM. FOLLOWING INSTALLATION OF THE NEW SYSTEM, THE DISTRICT CONSISTENLY REMAINED IN COMPLIANCE WITH THE LIMITATIONS OF ITS NPDES PERMIT.