Mosquito Spraying Coming To Wayland This Week

WAYLAND, MA — Annual mosquito spraying will return to Wayland this week, but the routine measure against mosquito-borne diseases has a new meaning this year due to the discovery of PFAS in a major town water supply.

In January, a company that manufactures the mosquito pesticide Anvil reported PFAS contamination in its product. Clarke Mosquito Control Products said PFAS leaked into the pesticide from shipping containers, and noted the chemicals are not used in Anvil itself.

In early April, Wayland officials said recent tests had uncovered PFAS levels above a state limit in the Happy Hollow well field, which supplies about 50 percent of the town's drinking water.

The East Middlesex Mosquito Control Project (EMCCP) is expected to begin spraying in Wayland the week of April 26. The pesticide that will be used is called Bti, and is a type of bacteria that kills certain insect larvae. Bti and Anvil are two different products, with the latter relying on the chemicals sumithrin and piperonyl butoxide to kill adult mosquitoes.

"A helicopter flying low directly over the wetlands will apply a dry, granular formulation of Bti. Residents do not need to take any special precautions for this application," the EMCCP said this week.

Wayland's mosquito spraying will take place at Pod Meadow and wetlands near Claypit Hill Road, Forty Acre Drive, Glenzen Lane, Concord Road and Plain Road.