Occurrence and Concentrations of Trace Elements in Discrete Tapwater Samples Collected in Chicago, Illinois and East Chicago, Indiana, 2017

This dataset contains the trace element concentration results for samples collected from tapwater sites in East Chicago, Indiana, August-September, 2017, and Chicago, Illinois, July-December, 2017. Samples were collected one time, from 45 private residences and associated drinking water plants and source water locations. Water-quality samples were analyzed at two U.S. Geological Survey laboratories: National Water Quality Laboratory, Denver, Colorado and at the Redox Chemistry Laboratory, Boulder, Colorado.