Maryland Department of Natural Resources

Arsenic Interactive Map for the Aquia and Piney Point aquifers

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In 2006 the U.S. Environmental Protection Agency lowered the Maximum Contaminant Level for arsenic from 50 to 10 μg/L for public-water systems and newly constructed domestic wells. Several community water systems in Maryland, particularly in Southern Maryland and the Delmarva Peninsula, were known from previous sampling to have ground-water arsenic concentrations that exceed the new standard, especially in the Aquia and Piney Point aquifers. A study was conducted to determine which Coastal Plain aquifers have elevated arsenic concentrations, the extent and range of arsenic in these aquifers, and to identify possible hydrochemical controls on arsenic distribution. Data on the following interactive maps is taken from MGS Report of Investigations 78.

The interactive map below provides information on the occurrence of arsenic in the Aquia aquifer. The red shaded area is where arsenic commonly exceeds the 10 ug/L drinking water standard.

 

The interactive map below provides information on the occurrence of arsenic in the Piney Point aquifer. The red shaded area is where arsenic commonly exceeds the 10 ug/L drinking water standard.