Pest-control costs high for Foster City 

Although it looks like a pleasant tree-lined suburb, Foster City is the site of an annual attack of blood-sucking creatures that rise from their underground lairs at dusk.

Because Foster City’s storm drain system lies below sea level, it relies on the water level of the lagoons, rainfall or pumped water to flush the system. When the lagoon levels and rainfall drop in the summer, water pools in the drainage system.

"In the summer, when there’s no rainwater, no freshwater flushing the system, it becomes more susceptible to mosquitoes and we have to treat it more," said Public Works Maintenance Manager Norm Dorais.

Several local species of mosquitoes — attracted to exhaled carbon dioxide — are known to travel indoors and bite during the night, possibly spreading blood-borne diseases such as West Nile virus.

All county cities but Foster City and Redwood Shores are able to pay for all of their mosquito-control needs through property taxes with a tax of approximately $1.86 for every $100,000 of a home’s value to fund the services.

Foster City has to pay up to $38,000 extra to the San Mateo County Mosquito Abatement District in the coming fiscal year for mosquito control.

The cost to the city rose this year from $36,000 last year and $35,000 in 2005 because gasoline prices and operations costs have risen for the abatement district. The district’s 10 spraying trucks also had to start a month early this year, because of less rainfall in the winter and an earlier start for warm weather.

"That’s the first time we’ve had to start this early in 21 years, we usually start in May," said district Operations Supervisor James Counts.

Each of the 10 trucks can cover 50 storm drains a day, and Foster City has more than 2,000. District employees spray a refined mineral oil into each drain to kill the aquatic mosquito larvae before they can finish their seven-day development.

"It’s been a continuous mosquito problem, but we’ve been able to keep it under control," Counts said. "It’ll be a problem forever, just because of the way the system was built."

Counts said the lagoon system itself has too much water movement to provide a breeding ground for mosquitoes.

To request mosquito service, call the San Mateo County Mosquito Abatement District (650) 344-8592 or write to


» More than 3,500 mosquito species

» 53 found in California; 20 common to Peninsula

» Female mosquitoes drink blood, males drink nectar

» Three species inhabit Foster City:

Culex pipiens

Culex tarsalis

Culex stigmatosoma

- Source: San Mateo County Mosquito Abatement District

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