ANDOVER — Mosquito spraying will take place either tonight or tomorrow night near the border of Lawrence and North Andover.
The Northeast Mosquito Control and Wetlands Management District will spray the pesticide Anvil from a truck between 9 p.m. and midnight.
"The ultra-low volume sprayers will cover an area about 300 feet from the street, depending on weather conditions, and will be used at a time when adult mosquito activity is at its highest, as the compound does not leave any residual in the environment," according to a letter to residents.
The letter says that the chemical is not dangerous to humans, but if people are concerned with a potential exposure, they should take action to avoid being the area of the spraying.
The spray-truck drivers will not be able to complete the application if people or dogs are seen along the roads. Residents are being asked to walk their dogs before 9 p.m. and stay indoors during the spray times.
Activities can continue within a few minutes of the spraying, according to the letter.
The area to be treated will be north of a line that runs from Route 125 Bypass Road and follows Prospect Road, Salem Street, Phillips Street, Reservation Road, to Beacon Street, toward the Lawrence and North Andover town boundaries. A map is available on the town's website, andoverma.gov.
The Board of Health authorized the limited spraying on Monday night after the Massachusetts Department of Public Health confirmed last Friday that it had detected West Nile virus in two mosquito traps in town. The areas where the traps were located include Sacred Heart Cemetery near the Lawrence border and the area of Chestnut Street at Morton Street in Andover, according to the town's health division.
The town joins North Andover, Boxford, and several other communities in the northeast who have had mosquitoes test positive for West Nile. Anvil was sprayed in North Andover two weeks ago.