The U.S. Geological Survey (USGS), in cooperation with the Great Lakes Restoration Initiative, collected data in 2017 to study the sources and occurrences of continual detections of high Escherichia coli (E. coli) detections at urban beaches along the Lake Michigan shoreline in northwest Indiana and northeastern Illinois. High E. coli detections cause the beaches to be closed for recreational use until additional samples verify that E. coli levels have fallen below the threshold of 235 counts per 100 ml. The project used microbial source tracking (MST) and metagenomics analyses to evaluate the sources of E. coli. This data release provides the phytoplankton, mictobial source tracking, and metagenomics components of the study and may be used in conjunction with continuous water-quality parameters and surface-water samples to understand biological and environmental indicators to help evaluate conditions conducive to high E. coli levels. In addition synoptic surveys of water quality, circulation/transport, and bathymetry were done to help study surface-water flow patterns. Groundwater samples were taken to compare with surface-water E. coli concentration results. Groundwater wells were installed at Jeorse Park Beach in 2017, and additional wells were installed at Whihala beach West in late 2017 and early 2018.
