Smoke from not one but two wildfires is sinking into the northern San Joaquin Valley, prompting pollution-control officials to issue an air alert.
The San Joaquin Valley Air Pollution Control District on Monday issued the alert, in effect through Wednesday in San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings and Tulare counties, and part of Kern County.
The Rim fire, burning in Tuolumne and Mariposa counties, grew overnight to 253,332 acres. More than 3,000 firefighters remain at the blaze, the third-largest in California history. The fire, caused by a hunters illegal campfire, started Aug. 17. It remains 80 percent contained.
On Sunday, a second fire broke out on the west side of the valley. The Morgan fire, burning southeast of Clayton in Contra Costa County, had consumed 1,500 acres and was 10 percent contained Monday. Authorities said 100 residences were threatened; mandatory evacuations were in place for several neighborhoods.
This weeks high temperatures expected to be in the mid-90s through at least Wednesday along with increased emissions and stagnant airflow, contribute to the formation of ozone in the valley. High ozone levels pose a health hazard and put the area at risk for exceeding the federal one-hour ozone standard, which in turn can trigger a federal penalty. Drivers would pay the $29 million penalty through a $12 addition to their DMV registration fee. Businesses also would face fee increases.
We are at an extremely critical point in our journey to meet this standard, Seyed Sadredin, the air districts executive director and air pollution control officer, said in a news release. As we get nearer to the end of ozone season, it becomes even more important to avoid an exceedance.
Officials have asked residents to refrain from unnecessary driving or car idling and to limit driving in the early morning and late evening hours.
In addition to fire, smoke and ozone troubles, some people may find their respiratory systems reacting to the start of the almond harvest, which stirs up clouds of dirt and dust.