Late Thursday afternoon the thick smell of smoke seeped into Stanislaus County from a controlled burn at least 30 miles to the south.
It was a no burn day in Stanislaus County, but not in Merced County.
A 400 acre controlled burn at the San Luis National Wild Life Refuge ended around noon but residents as far north as Village I started smelling the residual smoke around 4 p.m.
On Friday, both Merced and Stanislaus County residents will be allowed to burn cleanly.
Burning cleanly, as advised by the San Joaquin Valley Air Pollution Control District, includes:
-- Using an EPA Phase II-certified wood-burning device and burning dry, seasoned wood.
-- Never burn trash, magazines, newspapers, plastics or other materials not designed to burn in fireplaces or stoves. This is illegal and hazardous.
-- For a fire in an open fireplace, a manufactured fire log may be a cleaner alternative to wood.
Residential wood burning is the single largest source of harmful particulate matter during winter, pumping up to 17 tons into the valley sky each day, the district said in a news release.
The pollution is known to exacerbate respiratory illness, such as asthma, and can cause lung infections and bronchitis.
"Check Before You Burn runs though February. The district makes exceptions to the wood-burning prohibitions for homes that do not have access to natural gas service or any other source of heat.
Daily wood-burning forecasts are available at 4:30 p.m. at http://valleyair.org/aqinfo/WoodBurnPage.htm, by calling (800) 766-4463, or by subscribing to the districts daily air quality forecast at www.valleyair.org/lists/ list.htm.