There have been nearly 400 complaints of wood smoke in San Mateo County on Spare the Air Days since the winter season opened Nov. 1, and more than 300 potential violations on the Peninsula as of Thursday, air district officials said.

Spare the Air Days, of which the season's 15th will take place Saturday, alerts Bay Area residents when fine particulate -- or soot -- levels are anticipated to be unhealthy.

On Spare the Air Days, wood burning is prohibited -- though not everyone follows the law.

The number of wood smoke complaints in San Mateo County on Spare the Air Days reach 359 this week, and of those at least 338 potential violations were found, according to the Bay Area Air Quality Management District.

Whenever a wood smoke complaint is reported, it initiates the following Air District response:

• The complaint information provided places the address in our wood smoke complaint system to help direct wood smoke investigations. At a minimum, information about the wood smoke regulation and instructions how to comply will be mailed to the address.
• Once in our wood smoke complaint system, Air District Inspectors will routinely conduct wood smoke investigations throughout the Bay Area, generally where there are high numbers of wood smoke recorded and/or high rates of wood burning.
• Due to the sensitive nature of wood smoke complaints, Air District inspectors are not dispatched directly to meet with a complainant.
• When an Air District Inspector documents a violation, the violator will first be issued a warning letter giving the alleged violator an opportunity to correct the violation.
• Any subsequent violations observed by inspection staff at the address, may result in citation(s) and financial penalties.
• Second-time violations are subject to a $400.00 penalty. Subsequent violations will result in increasing penalty amounts.

Residents and businesses can call 1-877-4NO-BURN (1-877-466-2876) to check the Winter Spare the Air Alert status and to report wood smoke concerns in their area.