This is a message from Chester County Emergency Services

PA DEP will be conducting an aerial black fly (biting gnat) larviciding operation along the Schuylkill River Perkiomen and Tulpehocken Creek on July 1, 2019, beginning at approximately 8:30 AM. This aerial spraying activity will utilize a helicopter to apply Vectobac 12AS (also known as B.t.i.) to the aforementioned waterways in Montgomery, Chester, Berks, and Schuylkill counties.  Philadelphia borders the work being conducted in part of Montgomery County.

The helicopter used for this operation will be N655HA, a gray Bell 206 L-1 with red and blue stripes.  The aircraft is operated by Helicopter Applicators of Gettysburg, PA.  DEP personnel will be on site at all landing zones managing the operation.

Work on the Schuylkill River will take place between the Landingville Dam in Schuylkill County and the City Avenue bridge in Philadelphia.

Work on the Perkiomen Creek will take from Oaks to Spring Mountain.

Work on the Tulpehocken Creek will take place between the mouth and the Blue Marsh dam in Berks County.

The B.t.i. material is a naturally occurring bacteria (Bacillus thuringiensis israelensis) that kills the immature (larval) form of the black fly when they feed on it in the waterways.  This application of B.t.i. is not toxic to fish or other aquatic macroinvertebrates found in the treated waterways.

This work does NOT involve a helicopter spraying over the entire county.  This work is targeted to portions of specifically mentioned waterways.  The helicopter will apply B.t.i. to designated areas every few miles along the treated waterways.  Application is done by first circling the area to look for people on the ground or obstructions in the air. Then, the helicopter will fly perpendicular to the water flow (whenever possible) and apply the B.t.i. material which is a brown, viscous liquid with a fish oil odor to it. 

Any questions about the operation may be directed to contact below. Product labels or SDS sheets can be provided upon request by PA DEP.

Paul Mages | Aquatic Biologist I
Department of Environmental Protection | Southeast Regional Office
2 East Main Street | Norristown, PA 19401
Phone: 484.250.5196 | Fax: 484.250.5971
www.dep.pa.gov