YOUNGSTOWN IS A CHARTERED MUNI CORP, OWNS/OPERATES WSTWTR TRTMNT PLNT IN CITY NEXT TO MAHONING RIVER. W/IN PLNT ARE TWO MULTI-HEARTH SLUDGE INCINCERATORS, WHICH ALTER- NATELY OPERATE W/O CONTROL EXCEPT FOR SPRAY CHAMBER THAT ENTRAPS 15% OF PARTICULATES IN EXHAUST GASES. AN EXCESS OF 200 TPY OF SUSPENDED PARTICULATE MTTR IS EMITTED FROM CITY'S SINGLE EXHAUST STACK. OPACITY READINGS AS HIGH AS 90 AND 100% HAVE BEEN OBSERVED BY EPA PERSONNEL. APPLICABLE OHIO SIO RULES REQ CITY TO REDUCE PARTI- CULATE EMISSIONS TO SOMEWHAT UNDER 5 TPY BY 04/15/77; ALSO, RULES REQ OPACITY OF STACK'S PLUME NOT TO EQUAL OR EXCEED 20%. EMISSIONS CONTRIBUTE TO TOTAL SUSPENDED PARTICULATES OF MAHONING COUNTY, OHIO PRIMARY NONATTAINMENT AREA FOR PARTICULATE MATTER. EMISSIONS ARE IN VIOLATION OF OHIO SIP PARTICULATE RULE AP-3-10(B) AND OHIO SIP OPACITY RULE AP-3-07(A)(1) AND THE CLEAN AIR ACT. TO ACHIEVE COMPLIANCE, CITY MUST MAKE IMPROVEMENTS TO TWO SLUDGE INCINERATORS, AND RELATED FACILITIES, INCL INSTALLATION OF SCRUBBERS AND SLUDGE HANDLING FACILITIES. DUE TO STATUS AS A MUNI, GOOD FAITH EFFORT TO RESOLVE DISPUTE, AND PROPOSED REDUCTION OF EMISSIONS BELOW LEGAL LIMIT, A BOTTOM-LINE PENALTY OF $5000 IS RECOMMENDED.