Schuylkill River And French Creek To Be Sprayed For Black Flies

PHOENIXVILLE, PA — A chemical spray will be applied to a lengthy stretch of the Schuylkill River and French Creek to help fight black fly infestation.

It's part of a larger statewide effort to treat 48 different rivers and streams with the larviciding spray, using both aerial and on the ground treatments.

The Schuylkill will be treated throughout Chester County, as well as parts of Schuylkill County. The length of French Creek will also receive treatments. Work on that stretch and other nearby waterways will begin on May 21.

The spray used, Bti, is a "naturally occurring bacteria" that kills the flies in their immature form. The state Department of Environmental Protection says that the spray is not toxic to fish, birds, or other aquatic life.

“As warmer weather returns, black flies are a pest that can inundate folks seeking outdoor recreation, especially around rivers and streams,” DEP Secretary Patrick McDonnell said in a statement. “Using environmentally compatible methods, this annual initiative reduces this nuisance so that Pennsylvanians and visitors can fully enjoy our natural resources.”

Helicopters will be visible flying over local waterways, and ground crews will have backpack sprayers, often applying the treatment from over bridges.

Nearby, Perkiomen Creek from Oaks to Spring Mountain will also be sprayed, as well as parts of Manatawny Creek in Montgomery County, and the Delaware River and Tohickon Creek in Bucks County.