Development of pH TMDL's for two 303(d) Listed Streams in Western Kentucky: Cypress Creek in Muhlenburg County, Kentucky and Drakes Creek in Hopkins County, Kentucky

This project consists of a stream sampling and modeling effort for the development of TMDLs for two streams in the Green River basin impacted by Acid Mine Drainage (AMD) from Abandoned Mine Lands (AML). The streams include Drakes Creek (river mile 0.0 to 8.5) and Cypress Creek (river mile 22.9 to 33.0). The project shall be coordinated by the Kentucky Water Resources Research Institute at the University of Kentucky (KWRRI) and shall also involve scientists and students from Murray State University. The KWRRI shall be responsible for project management, model development, and TMDL development. Murray State University shall be responsible for collection of flow and pH samples from selected sites in each basin. The work plan for this project shall follow a similar work plan previously employed in the development of a pH TMDL for Brier Creek Watershed (Kentucky Division of Water, 2000) and as recently approvedby Region IV of federalEPA. These steps are summarized as follows: . 1.Collect flow and pH readings at pre-selected sites in both watersheds (Murray State). 2.Convert pH readings to ion loadings using the measured flows and an activity correction factor of 0.89 (KWRRRI). . 3.Develop loading models for each site using the converted load values and the associated discharges (KWRRI). 4.Develop regional frequency discharge relationship as a function of frequency and watershed area using available regional USGS gauging stations (KWRRI). 5.Compute TMDL values for each site assuming a minimum pH reading of 6 and a activity correction factor of 0.89 by making use of the frequency model developed in step 4 and the function relationship between pH and hydrogen ion load equivalents (KWRRI). 6.Compute load reductions for each site using the functional relationships developed in steps 3 and 4 (KWRRI).