Skip to content

Treatment Scheduled for Black Fly Control on Potomac River

HAGERSTOWN, MD (August 19, 2019) – Washington County Government would like to notify all citizens that the Maryland Department of Agriculture, in partnership with the Department of Natural Resources, will treat targeted areas of the Potomac River in Washington County as an ongoing effort to control the black fly population. Treatment is scheduled for Tuesday, August 20, 2019 beginning at 8:30 a.m.

The department will apply a Bacillus thuringiensis israelensis (Bti)-based larvicide via helicopter (Bell 206 Long Ranger, green and white paint scheme. Tail number N641HA). Bti is a naturally occurring bacteria found in soils worldwide. It is a bacterial insecticide, not a chemical, and is only harmful to a very limited variety of organisms including midge, black fly, mosquito larvae and a few other aquatic Dipteran (flies) insects.

The treatment may cause temporary discoloration of the water, but it is completely non-toxic and is not harmful to humans, fish, crabs, or other aquatic invertebrates.

For additional information, please contact Washington County’s Public Relations and Marketing Department at 240-313-2380.

###

Other news:

TRAFFIC ALERT: Road Closure on Kemps Mill Road

TRAFFIC ALERT: Road Closure on Kemps Mill Road

WILLIAMSPORT, MD (February 27. 2026) – The Washington County Highway Department announces the upcoming closure of Kemps Mill Road, between Pinesburg Road…
Washington County Commissioner Derek Harvey Resigns

Washington County Commissioner Derek Harvey Resigns

The Washington County Board of County Commissioners announces that Commissioner Derek Harvey has submitted his resignation, effective February 24, 2026.Commissioner Harvey…
TRAFFIC ALERT: Road Closure on Mondell Road

TRAFFIC ALERT: Road Closure on Mondell Road

SHARPSBURG, MD (February 24, 2026) – The Washington County Highway Department announces an upcoming road closure on Mondell Road between 5320 and…