This data release supports the following publication: Senior, Lisa A., 2017, Estimated Fecal Coliform Bacteria Concentrations Using Near Real-Time Water-Quality and Streamflow Data From Five Stream Sites in Chester County, Pennsylvania, 2007–16: U.S. Geological Survey Scientific-Investigations Report 2017–5075 (https://doi.org/10.3133/sir20175075) The U.S. Geological Survey (USGS), in cooperation with the Chester County Health Department (CCHD) and the Chester County Water Resources Authority (CCWRA), has collected discrete stream samples for analysis of fecal coliform concentrations during March– October annually at or near five gaging stations where near real-time continuous data on stream discharge, turbidity, and water temperature have been collected since 2007 (or since 2012 at 2 of the 5 stations). In 2014, the USGS, in cooperation with the CCWRA and CCHD, began to develop regression equations to estimate fecal coliform concentrations using available near real-time continuous data . Regression equations included possible explanatory variables of stream discharge, turbidity, water temperature, and seasonal factors calculated using Julian Day with base-10 logarithmic (log) transformations of selected variables. Data files in CSV format include datetime, stream discharge, in cubic feet per second, water temperature, in degrees Celsius, fecal coliform bacteria concentrations, in colonies per 100 milliliters, turbidity, in FNU, Julian Day, and calculated or transformed variables of log fecal coliform concentrations, log turbidity, sin(Julian Day/365), and cos(Julian Day/365)]. Data were collected at 5 stream sites, French Creek at Phoenixville Pa., White Clay Creek near Strickersville, Pa., East Branch Brandywine Creek below Downingtown Pa., West Branch Brandywine Creek at Modena Pa., and Brandywine Creek at Chadds Ford, Pa.