Gambrills Well Water Investigation

The Anne Arundel County Department of Health began its Gambrills/Odenton well water investigation in October 2006 in response to notification from the Maryland Department of the Environment (MDE) and Constellation Energy Group of high levels of metals found in the well water of a home on Summerfield Road in Gambrills. Summerfield Road is within 1,000 feet of a coal ash fill site.

From October 12, 2006, through April 23, 2007, the Department of Health conducted well water testing for 83 homes and businesses on Summerfield Road and in a surrounding area that was recommended by MDE. See Map: Expanded Well Water Testing Area Samples collected from some of these wells showed levels of aluminum, arsenic, beryllium, cadmium, lead (often plumbing-related), manganese, sulfates and thallium that exceeded maximum contaminant levels (MCL) or recommendations set by the U.S. Environmental Protection Agency (EPA) for drinking water. These substances are constituents of fly ash. See Test Results Summary. See Chart: Health Facts.

This investigation demonstrates the ability of fly ash components to leach out of a mining operation into groundwater and contaminate drinking water wells.

The Department notified the property owners of their individual test results and those with MCL exceedances were advised to avoid ingesting well water to reduce their exposure to contaminants and protect their health. The test results were reported to MDE. The Department worked with the affected well owners and MDE to provide short-term recommendations, such as use of bottled water. The Department suggested permanent remedies, namely access to public water or safe replacement wells.

By March 2014, the installation of a cap at the Waugh Chapel sand and gravel pit was completed. Public water connections were completed in 2015 for all affected properties. In 2016, the installation of a groundwater remediation system for the Waugh Chapel pit was completed.

Constellation Energy Group is required to submit quarterly reports and an annual groundwater trend analysis. This has continued to date. The most recent reports note that sulfate at assessment wells show an increasing trend. If levels increase to an action level of 150 mg/L, Constellation may increase the pumping rate of recovery wells in an effort to remediate an increase of the plume. MDE has recommended that future analysis of trends include nitrate and cadmium.

Only private wells serving residential homes and businesses were involved in this investigation. Most properties in the identified area use public water, which meets EPA standards.

For more information about the Department’s Well Water Quality Program, call 410-222-7189 on weekdays from 7:30 a.m. to 4:00 p.m.