Anacostia River - Northwest Branch

Source Information

Anacostia Riverkeeper (ARK) staff, interns, and volunteers test water quality for citizen science water quality monitoring programs at access points along the watershed in DC and MD waters. In DC, funded by DC Department of Energy and Environment (DOEE), Anacostia Riverkeeper, Rock Creek Conservancy, and Audubon Naturalist Society have joined a partner team led by Alliance for the Chesapeake Bay to conduct community-based water quality monitoring throughout DC's primary watersheds. Testing will occur monthly at 24 sites along the Anacostia River, Rock Creek, and Potomac River starting in May 2021 for bacteria, water temperature, air temperature, pH, and turbidity. In Montgomery County, MD, ARK will have citizen science monitoring made possible through the Montgomery County Watershed Restoration and Outreach Grant program funded through the Montgomery County, MD Water Quality Protection Fund in partnership with the Chesapeake Bay Trust, Alliance for the Chesapeake Bay, Friends of Sligo Creek, and Neighbors of Northwest Branch. Testing will occur bi-weekly at 5 sites starting in May 2021. Each site will be sampled for bacteria, water temperature, air temperature, dissolved oxygen, conductivity, pH, and turbidity. In Prince Georges County, MD, ARK will have citizen science monitoring. Testing will occur bi-weekly at 3 sites starting in May 2021. Each site will be sampled for bacteria, water temperature, air temperature, dissolved oxygen, conductivity, pH, and turbidity. Bi-weekly testing in Prince Georges County and Montgomery County will occur on opposite weeks. ------ The District and county agencies recommend not swimming in the water for 48 hours after a rain event of 0.5 inches or more. There is a current DISTRICT-WIDE SWIM BAN so even if a site is “green” or considered passing, do NOT swim there. Avoid wading and playing in the water as well, as hand to mouth transmission can occur after touching contaminated water. The main water quality parameter reported is E. coli, a fecal coliform. E. coli is measured in terms of the Most Probable Number /100 ml water and is an indicator of fecal contamination and harmful pathogens that can cause gastrointestinal and skin infections. Samples recording less than 126 MPN E. coli /100ml are therefore considered "green", having met water quality standards set by the District for the geometric mean. Samples over the standard are considered "red" due to their failure to meet criteria, and the increased risk of illness. We report single sample values but refer to the geometric mean bacteria cutoff to be more conservative and protective of recreational health. For more information about results, go to https://www.anacostiariverkeeper.org/water-quality/.