This data release provides water chemistry results and quality assurance data for samples collected from Great Lakes tributaries in the states of Minnesota, Wisconsin, Michigan, Indiana, Ohio, and New York. In total, 158 chemicals were analyzed which are primarily pharmaceuticals. Between one and four water samples were collected at 37 sampling locations between November 2017 and July 2018 resulting in a total of 87 environmental, 95 field replicate, and 15 field blank samples. Of the 158 chemicals analyzed, 23 chemicals were detected in at least one regular sample. Detections per site ranged from 0 to 12 chemicals at concentrations of 1.56 to 30900 nanograms per liter. Sample collection and analysis was performed by the U.S. Geological Survey and summarized in the associated journal article (https://doi.org/10.1002/etc.5403). More detailed method descriptions will be published in the future.