Role of Total Maximum Daily Load Decisions for Water Quality in Mill Creek (Cincinnati)

Stone, H. J. and O. L. Loucks
Department of Botany
Miami University, Oxford, OH 45056

To be presented at Ecological Society of America Annual Meeting
Madison, WI
Aug. 5-10, 2001

The Clean Water Act requires new approaches for recovery of water bodies that fail to meet required water quality standards. Classification as the "highest priority" impaired water, as is the case for the Mill Creek in the Cincinnati area, then triggers establishment of total maximum daily [pollutant] loads (TMDL) as measures to ensure achievement of water quality standards. Under threat of court order, the Ohio Environmental Protection Agency has worked within challenging timelines to establish a TMDL for its highest priority waters, including the Mill Creek. This paper examines the question, do present data indicate that a TMDL will achieve water quality standards? A substantial body of IBI, ICI, habitat quality, nutrient, and pollutant concentration data from monitoring by the Ohio EPA were analyzed, along with the TMDL recommendations, to answer this question. A parallel sociopolitical process used to develop the TMDL was highly inclusive of the stakeholders - industry, environmental groups, waste treatment facilities and 34 governments in the watershed. The Mill Creek situation presents a myriad of technical environmental challenges, from superfund sites to combined sewer overflows. The Phase I TMDL development process results in a good deEmition of the problem, but it unduly constrains consideration of available options.