Air quality monitoring in Portola for January has shown some improvement over December, according to Julie Ruiz of the Portola branch of the Northern Sierra Air Quality Management District.
Temperatures stayed low, so woodstoves were still heavily used, but according to tracking data, there were only six days in January where particulate levels exceeded National Ambient Air Quality Standards.
This is a much lower total than in December, which had a total of 13 days above the NAAQS, and a great improvement over air quality standards in January 2016, which had 17 days over the NAAQS. The main factor in cleaner air quality, according to Ruiz, was a large amount of precipitation. There were 15 recorded days of precipitation in January 2017, totaling nearly 15 inches of rainfall for the month.
One other contributing factor to better air quality may be the cleaner-burning woodstoves in the area due to the change-out program. As of February 2017, 110 installations have been completed and 154 pre-approval letters have been sent out.