News from the DNR Office of Communications

DNR and MDE Release "Arsenic In Ground Water In The Coastal Plain Aquifers Of Maryland" Report

Report can be used to assure safety of drinking water

Annapolis, MD (July 20, 2010) — The Maryland Geological Survey (MGS), in cooperation with the Maryland Department of the Environment (MDE), today released a new report regarding information that residents and government officials can use to minimize exposure to naturally occurring arsenic in drinking water.

The MGS report, “Arsenic in Ground Water in the Coastal Plain Aquifers of Maryland,” shows where arsenic naturally occurs in the major aquifers in the Coastal Plain of Maryland, which includes the southeastern half of the state, the area approximately southeast of Interstate 95. The report found that arsenic in the groundwater is naturally occurring and that it exceeds federal standards in certain areas of two Coastal Plain aquifers.

“This report provides important information to water-supply managers, county health departments, and ground-water scientists on where elevated concentrations of groundwater arsenic are likely to occur, and some possible reasons why arsenic is elevated in some areas but not in others,” said Jeffrey P. Halka, Acting Director of MGS. “With this information, officials and residents can take steps to avoid water with elevated levels of arsenic, or know that they should consider taking action to reduce exposure to arsenic.”

The report, by David D. Drummond and David W. Bolton, presents the findings of a study that began in 2001 in response to a request from the Maryland Department of the Environment. The Department contracted MGS to perform the study in response to the lowering of the U.S. Environmental Protection Agency's Maximum Contaminant Level for arsenic from 50 micrograms per liter to the more protective standard of 10 micrograms per liter.

Data from more than 4,200 wells were evaluated to determine the presence and geographic distribution of arsenic in Maryland's Coastal Plain aquifers. The findings show that the vast majority of the Coastal Plan aquifers are not impacted and that the Aquia and Piney Point aquifers are the only Coastal Plain aquifers with water that exceeds the revised federal standard.

Elevated arsenic concentrations in the Aquia aquifer form a band that extends from the Eastern Shore, beneath the Chesapeake Bay, and into Southern Maryland. An additional area of elevated arsenic concentrations was identified in the Mayo peninsula in Anne Arundel County.

Elevated arsenic concentrations in the Piney Point aquifer form a band similar to the one in the Aquia aquifer, only narrower and farther to the southeast. Additional small areas of elevated concentrations were found north of the main band in Talbot and Queen Anne's counties.

Chronic ingestion of water containing elevated levels of arsenic could cause a variety of health problems, including skin, lung, bladder, and kidney cancer, and skin discoloration and thickening.

Drinking water utilities are required to inform customers of any arsenic level above drinking water standards in their drinking water.

Residents on private wells can check with their local health department for information on levels of arsenic in the drinking water supply in the area. Residents who live in an area with elevated arsenic levels in the groundwater, or who live in an area for which information is not available, should consider having their well water tested to determine the level of arsenic present. A variety of treatment options exists, or residents may consider installing a new well, using bottled water, or connecting to a public water source.

The report was conducted by MGS, a division of the Maryland Department of Natural Resources, in cooperation with MDE. The report is available online at

Health information on arsenic in drinking water and information on water treatment options for individual wells can be found at

Information on arsenic can also be found at

   July 20, 2010

Contact: Josh Davidsburg
410-260-8002 office I 410-507-7526 cell

Jay Apperson
410-537-3003 office, 443-604-0091 cell

The Maryland Department of Natural Resources (DNR) is the state agency responsible for providing natural and living resource-related services to citizens and visitors. DNR manages more than 449,000 acres of public lands and 17,000 miles of waterways, along with Maryland's forests, fisheries, and wildlife for maximum environmental, economic and quality of life benefits. A national leader in land conservation, DNR-managed parks and natural, historic, and cultural resources attract 12 million visitors annually. DNR is the lead agency in Maryland's effort to restore the Chesapeake Bay, the state's number one environmental priority. Learn more at