Second report on the Oak Ridge K-25 Site Biological Monitoring and Abatement Program for Mitchell Branch

Abstract

On September 11, 1986, a modified National Pollutant Discharge Elimination System permit was issued for the Oak Ridge Gaseous Diffusion Plant (ORGDP; now referred to as the Oak Ridge K-25 Site), a former uranium-enrichment production facility. As required in Part III of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed for the biological monitoring of Mitchell Branch (K-1700 stream) and submitted for approval to the US EPA and the Tennessee Department of Environment and Conservation. The plan described biomonitoring activities that would be conducted over the duration of the permit. The objectives of the BMAP are to demonstrate that the effluent limitations established for the Oak Ridge K-25 Site protect and maintain the use of Mitchell Branch for growth and propagation of fish and other aquatic life, and to document the effects on stream biota resulting from operation of major new pollution abatement facilities. The BMAP consists of four tasks: ambient toxicity testing; bioaccumulation studies; biological indicator studies; and ecological surveys of stream communities, including benthic macroinvertebrates and fish. This document is the second in a series of reports presenting the results of the studies that were conducted over various periods of time between August 1987 and June 1990.