Fecal-Indicator Bacteria Concentrations in the Illinois River between Hennepin and Peoria, Illinois

Portions of the Illinois River in Peoria, Woodford, and Tazewell Counties, Illinois, are designated as impaired by the Illinois Environmental Protection Agency (IEPA) owing to the presence of fecal coliform (FC) bacteria (Illinois Environmental Protection Agency, 2008). FC bacteria are used as an indicator of possible pathogens. Elevated concentrations of FC bacteria could cause a violation of the State waterquality standard for general-use waters primarily because of potential ingestion or physical exposure. Epidemiological research has demonstrated a relation between illness rates and the proximity to known FC bacteria point sources (Cabelli and others, 1982; Wade and others, 2006).