Survey of major and trace elements in stormwater runoff from across the United States, 2016 to 2017.

This study focuses on providing a broad-scale assessment of composition of water chemistry in urban stormwater runoff. The stormwater runoff is a source of recharge to groundwater by Green Infrastructure (GI) practices or it may become a source of recharge to groundwater to reduce stormwater volumes to surface waters or augment groundwater supply. The chemical composition of the stormwater runoff is important to understanding the potential impacts of surface water recharge to groundwater. In this study, 21 field sites were sampled for stormwater runoff during 50 storm events from 7/28/2016 through 12/8/2017. Major elements were measured by inductively coupled plasma-optical emission spectrometry and trace elements were measured by inductively coupled plasma-mass spectrometry. Each sample was analyzed in triplicate and the averages and standard deviations are reported. The results from analyses of associated quality assurance samples (field blanks, field duplicates, and average laboratory blanks) also are presented.