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Arsenic in groundwater of the United States

Map of arsenic in groundwater of the US
Arsenic in groundwater is largely the result of minerals dissolving from weathered rocks and soils. Several types of cancer have been linked to arsenic in water. In 2001 the US Environmental Protection Agency lowered the maximum level of arsenic permitted in drinking water from 50 micrograms per liter (ug/L) to 10 ug/L.

The USGS has developed maps that show where and to what extent arsenic occurs in groundwater across the country. The current maps are based on samples from 31,350 wells. Widespread high concentrations were found in the West, the Midwest, parts of Texas, and the Northeast. See Ryker (2001) for more information. See Focazio and others (2000) for the use of available data for characterizing arsenic concentrations in public-water supply systems. See Gronberg (2011) for updated arsenic map.

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United States
Northern US
New England
Map showing arsenic in groundwater in New England
Map showing arsenic in groundwater in midwestern glacial deposits

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Page Last Modified: Thursday, 17-Nov-2011 16:34:33 EST