Special Report No. 73-03: An Analysis of the Performance of Activated Sludge and Aerated Stabilization Basin Systems in Controlling the Release of BOD5 in Treated Mill Effluents to

The attached special report summarizes the findings of an NCASI staff study of the current operational performance of forty-three (43) activated sludge and aerated stabilization basin treatment systems with respect to discharge of BOD5. It was performed by David B. Buckley, Research Engineer, under the guidance and in association with James J. McKeown, Northeast Regional Engineer. The report contains a compilation showing the type of treatment process employed the existence in the case of aerated stabilization basin systems of post-aeration storage facilities with some bio-oxidation capability, average BODs discharge levels on a per ton basis, and their statistical variability. The report then proceeds to analyze the performance of all forty-three (43) systems against the provisions of the Effluent Limitation Guidance (a) originally distributed by EPA in June 1972 for use by EPA Regional Offices in preparing discharge permits under the EPA-CE-Refuse Act Permit Program (RAPP) and (b) more recently in use for preparation of EPA-NPDES discharge permits under the 1972 water pollution control legislation. The report notes that if literally interpreted, the Schedule B allowances fail to conform with the performance of two-thirds of the mills whose extensive records were analyzed. If, however, the BOD5 discharge per ton allowances are considered as allowable annual average performance they then conform to the performance of the great majority of the installations studied.