Innovative Approach for Developing Effluent Bod5 Limits, 1993 Environmental Conference Proceedings

The Mead Corporation requested a modification of the effluent BOD5 and release limits for their Mahrt Mill on the Chattahoochee River because of a planned mill expansion. Because river dissolved oxygen levels are occasionally less than the 5.0 mg/l standard, even without the Mead wastewater discharge, the conventional approach of setting effluent BOD5 limits to meet the dissolved oxygen standard at 7QlO flow conditions was not applicable. An alternative approach that combined water quality modeling with analysis of five years of Mead’s river monitoring data was developed River dissolved oxygen levels were computed over a five year period for the conditions of no Mead wastewater discharge and Mead at a proposed BOD5 limit. The results were summarized in terms of Mead’s effect on the average river dissolved oxygen concentration and also the increased frequency that river dissolved oxygen would fall below the 5.0 mg/l standard as a consequence of Mead’s proposed BOD5 limits. After reviewing the results of this alternative analysis, the Alabama Department of Environmental Management (ADEM) approved Mead’s proposed limits.