Arsenic, nitrate, and chloride in groundwater, Oakland County, Michigan

Abstract

In 1996, the U.S. Geological Survey (USGS), in cooperation with the Michigan Department of Environmental Quality (MDEQ) and nine southeast Michigan counties, began a study of the factors controlling arsenic concentrations in drinking water. The early results of this study raised broader concerns in Oakland County about the quality of groundwater in general and drinking water in particular. In response to these concerns, Oakland County worked with the USGS and the Center for Applied Environmental Research at the University of Michigan - Flint (CAER) to study distributions of arsenic, nitrate and chloride in groundwater, with emphasis on sites where concentrations of these constituents exceeded the Maximum Contaminant Levels (MCLs) and Secondary Maximum Contaminant Levels (SMCLs) set by the U.S. Environmental Protection Agency (EPA). The maps produced for this report are based on historical data compiled from MDEQ records.