West Nile virus hasn't claimed any lives in Alameda County, but it has taken its toll on the Alameda County Mosquito Abatement District.

Fighting the mosquito-borne disease has cost the district about $280,000 a year since 2003. Because of that added expense and ongoing inflation, the district, which covers all of Alameda County except for Albany, is seeking to raise the maximum amount it can collect from homeowners from $1.74 to $5 a year.

If approved, the additional tax would raise as much as $2.1 million a year for the district — nearly equivalent to its current $2.7 million annual budget — should it choose to charge the maximum amount. During the past 25 years, however, the district has charged the maximum assessment just six years.

Ballots, which already have been mailed to all property owners in the district, must be returned postmarked no later than April 30.

The district, which comprises 13 employees, devotesmost of its efforts to eradicating mosquito larvae in creeks, marshes, storm drains and flood control channels. It also surveys mosquito populations and tests them for transmittable diseases, district Manager John Rusmisel said.

Additionally, it responds to public complaints about potential mosquito breeding grounds — often a neighbor's swimming pool — and offers free larvae-eating fish.

In the Tri-City area, the district uses helicopters to drop larvae-killing bacteria in Coyote Hills.


It also treats mosquito breeding grounds among the eucalyptus trees in Ardenwood Park, the lagoon at Central Park and the salt marshes in Fremont and Newark.

To combat West Nile virus, the district hires seasonal workers to drop larvae-killing materials into every roadside storm drain grate in the county.

Although no known West Nile cases have been caused by mosquito bites in Alameda County, mosquitoes carrying the disease have been found in Coyote Hills Regional Park, the western edge of Stevenson Boulevard in Newark, Bay Farm Island in Alameda and several sites in and around Pleasanton and Livermore, Rusmisel said.

The results of the tax assessment vote will be released May 14.

If it fails, the district expects to shed two positions and also might have to buy cheaper, less environmentally friendly larvae-killers, as well as start charging for larvae-eating fish, Rusmisel said.

Tax approval would allow the district to add an environmental specialist and lab assistant to better conduct surveillance and research projects, and to hire more help during West Nile season.

It also would use some of the $2.1 million to restore its budgetary reserve and start funding employee retirement benefits, Rusmisel said.

The new assessment would vary based on the property.

Single-family homeowners would pay a maximum of $5 a year and condominium owners would pay up to $3. The tax would be steeper for owners of commercial property. They would pay a maximum $2.50 per quarter acre for the first five acres and then $2.50 for every additional acre.