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Aerial Larvicide Treatment - August 11th, 2022

Annex Lake, Mills Field, & Sharp Park

Weather permitting, San Mateo County Mosquito and Vector Control District will conduct aerial mosquito larvicide applications over water at Annex Lake (Stanford) and Sharp Park lagoon in Pacifica. The treatment originally scheduled for August 10th will be occurring on August 11th.

The product we’ll be using is a solid granular (not a liquid spray) bio-rational mosquito larvicide; it targets mosquito larvae only and does not pose a risk to humans, pets, wildlife, fish, or the environment. It is applied by helicopter or unmanned aerial system (drone) in order to allow the product to reach the water in areas with dense vegetation, and to avoid the environmental impacts created by treating these areas on foot.

You may see or hear a helicopter or drone above or near the application area. At Annex Lake there will be no closure of public areas. At Sharp Park, some sections of the levee along the west side of the golf course will be briefly closed (5-10 minutes at a time) to allow the helicopter to land safely; if a drone is used, no closures will occur. The golf course, beach, Mori Point, and the levee in general will NOT be closed.

More information about helicopter larviciding can be found at If you have further questions about this application please call (650) 344-8592 or email

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