Skip to content

Treatment Scheduled for Black Fly Control on Potomac River

HAGERSTOWN, MD (July 23, 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 Thursday, July 25, 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 nontoxic 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 of Huyett Lane

TRAFFIC ALERT: Road Closure of Huyett Lane

HAGERSTOWN, MD (October 6, 2025) – The Washington County Highway Department announces the upcoming road closure of Huyett Lane between Route…
TRAFFIC ALERT: Road Closure on Hoffmaster Road

TRAFFIC ALERT: Road Closure on Hoffmaster Road

KNOXVILLE, MD (October 6, 2025) – The Washington County Highway Department announces an upcoming road closure on Hoffmaster Road between 1630…
MDOT Consolidated Transportation Plan Notice

MDOT Consolidated Transportation Plan Notice

HAGERSTOWN, MD (October 6, 2025) – The Washington County Division of Engineering will host the Maryland Department of Transportation (MDOT)’s Consolidated…