The Mohawk River Basin, located in east-central New York, is one of the most important water resources in the state, and has received priority clean-up status under the National Water Resources Development Act of 1990 (U.S. Congress 1990). Section 303(d) of the 2010 list of impaired waterbodies lists pathogens as the pollutant for the TMDL for both Portion 14 and Ninemile Creek. The ultimate goal of the project is to develop a pathogen Total Maximum Daily Load (TMDL) which eliminates the impairments in Ninemile Creek and Portion 14 to a level that achieves recreational use standards.
Characterizing the bacterial sources of an impaired watershed usually requires significant effort. The EPA Bacterial Indicator Tool, based on literature values of bacterial counts from animal populations, is an efficient and convenient tool to make this data gathering process easier. This article presents a case study where the Bacteria Indicator Tool was applied for estimating coliform built-up and wash-off parameters, which were used as input to an Interactive Windows Interface to HSPF (WinHSPF) program for a TMDL study. The paper summarizes and discusses the data and assumptions applied to the project, its findings and conclusions.