Pathogen and Nutrient Enrichment TMDL for Beargrass Creek Watershed in Jefferson County, Kentucky

The proposed project will include data collection, watershed characterization, modeling, stakeholder involvement and subsequent TMDL development for four streams listed as first priority in the 1990 and subsequent 1994 303(d) List of Waters for Kentucky. These streams are the South Fork, Middle Fork, Muddy Fork, and main stem of Bear grass Creek, Jefferson County, Louisville, Kentucky. These streams are listed because of pathogens (1990) and nutrient enrichment/dissolved oxygen (1994) and do not meet the Designated-Use Criteria for Primary Contact Recreation and Aquatic Life. The project uses an innovative approach to TMDL development and will also have a technology transfer component. The project will be completed within two years of grant award (the tentative award date is Septembe.r 2003) and will result in the development of two TMDL Reports consisting of nine individual listings as shown in the 2002 303(d) Report. The two TMDL Reports will be a (1) Pathogens TMDL Report consisting of five individual listings (Middle Fork Beargrass Creek - 2 segments, South Fork Beargrass Creek - 2 segments, and Muddy Fork - 1 segment), and a (2) Nutrient EnrichmentlDissolved Oxygen TMDL Report consisting of four individual listings (Middle Fork Beargrass Creek - 1 segment, South Fork Beargrass Creek - 2 segments, and the main stem of Beargrass Creek - 1 segment). Both TMDL Reports will be completed by the project end date (September 30, 2005). Jefferson County is located in north-central Kentucky and is the most densely populated county in the state. Beargrass Creek, which is located in Jefferson County, is included in the state's Salt River Basin Management Unit, although the creek drains directly to the Ohio River. Beargrass Creek has been - selected as a high pnority watershed (3 of 60 watersheds were selected) in the Salt River Unit. Beargrass Creek consists of three sub-basins: South Fork (27.0 mi2), Middle Fork (25.1 me), and Muddy Fork (8.9 mi2). The dominant land use in all three sub-basins is single-family residential, followed by paved (impervious) surfaces (roads and parking lots), parks, and cemeteries. The Muddy Fork and upper South and Middle Fork sub-basins are sewered with separate sanitary and stonn sewers. The lower South and Middle Fork sub-basins are drained by a complex system of combined sanitary and stonn sewers, with few open channels. There are 37 sanitary sewer overflow (SSOs), 64 combined sewer overflow (CSO) and over 1000 separate stonn water overflow points to the creek. The watershed has a mix of both point and non-point sources and will thus provide an excellent case study for the development and application of the proposed methodologies. The proposed approach will constitute a mix of applied and fundamental research expected to generate useful tools as well as to advance science. Applied research will evaluate the effectiveness of linking HSPF, XPSWMM, and GEMS (or alternate 3-D receiving water model) for use in simulating dissolved oxygen violations, the frequency of fecal colifonn violations, analyzing and delineating the water quality impacts to an urban receiving water, as well as developing load reduction targets. This project will likely provide a model for TMDL development in complex, urban stream systems. The project is a collaborative effort between the KDOW, KWRRI, and MSD. The MSD has already perfonned significant work on elements necessary for developing the TMDLs (See Table 1), and are committing significant additional resources in the fonn of non-federal match toward this proposal. The specific goals of the project will be achieved by satisfying the following objectives: . To complete the development ofa comprehensive watershed model, linking HSPF and XPSWMM, for the purpose of analyzing the impacts of wet-weather sources on an urban watershed impacted by stonn water and non-point runoff, SSOand CSO discharges. . To develop and refine the receiving water-body element to model the fate, transport and assimilative capacity of the stream system for fecal colifonns and dissolved oxygen. . To evaluate the efficiency of linking HSPF, XPSWMM, and GEMS (or alternative 3-D model) for analyzing the wet-weather impacts of a combined sewer system on an urban receiving water. . To collect a spectrum of pathogen species (i.e. total colifonn, atypical colifonn, fecal colifonn, and E. coli) at targeted sampling locations in the Beargrass Creek watershed and use the data to calibrate and QAJQC the associated models and assumptions of fecal colifonn sources. . To explore the use of neural-network technology in the development of pathogen loadinglwashoff models for use in the calibration and QAJQC of the comprehensive watershed model. . To collect high-resolution (continuousiy recording, multi-meter probes locate4 at 21 stream site~) dissolved oxygen data for model verification.