UPDATE: Sept. 12, 6 p.m. — Acreage burned has reached 255,858. Number of personnel was reduced to 2,572. Fire activity was minimal today, except north of Hetch Hetchy and interior pockets of unburned fuels, according to the Stanislaus National Forest.
Crews continue to make progress on fully containing the Rim Fire, but air quality concerns are expected to stick around for months, experts said.
The fire has burned 255,560 acres, up about 400 acres in the last 24 hours, and remains at 80 percent containment.
The fire has continued to grow slowly in the north and northeast while firefighters are in the “patrol, mop-up and monitor” phase, and growth potential lowered to high from extreme.
Incident Commander Jerry McGowan, leading the Rim Fire fight, confirmed to community members Wednesday evening at a Groveland community meeting that crews are on a “good path” to the Sept. 20 full containment date, but that smoke will be around up to two months after that.
The Tuolumne County Air Pollution Control District will decide midday Friday whether to lift the air quality warning that’s been in effect for over three weeks or keep it a few more days, according to Bill Sandman, deputy air pollution control officer.
Tuolumne County on balance has “moderately” good air quality, per the Environmental Protection Agency’s hourly Air Quality Index this morning, but quality bordered on “unhealthy for sensitive groups” and “unhealthy” in Groveland.
“Moderate” means air quality should only affect individuals with illnesses or conditions that make them unusually sensitive to air quality — not broadly including groups like children and the elderly.
The EPA forecast for the day showed nothing worse than “moderate” in all of California for the first time since severe fire impacts.
“Overall, we’re experiencing better air quality,” Sandman said, citing this morning’s monitoring data, acreage burning and local weather — the same factors that will be weighed for Friday’s decision.
However, less than “good” air quality is likely to stick around for at least weeks, maybe months, he said.
Dr. Todd Stolp, of the Tuolumne County Public Health Department, said air quality may be improving, but the cumulative exposure of Mother Lode residents to the fire’s smoke will continue to be a concern.
He still advised most residents to follow a 5-mile visibility standard, not performing any activity outdoors if visibility is less than 5 miles, but extended a 10-mile visibility standard to those who have been and continue to perform outdoor activity like jogging or manual work.
Generally, morning hours are worst and evening hours are best, but Stolp said ultimately individuals need to assess conditions at the time and place, including finding landmarks to identify visibility in miles.
For example, looking at Duckwall Mountain from Summerville High School is about 5 miles.