Air quality presentation highlights watershed meeting

  When a regulatory agency comes to town one can only hope it brings good news and that was the case when Northern Sierra Air Quality Management District Executive Director Gretchen Bennitt made a presentation at the Almanor Basin Watershed Advisory Committee meeting May 9.

  In addition to ABWAC representatives Lorena Gorbet, Carl Felts, Charlie Plopper, Dick Daniel, Aaron Seandel, Jeff Greening, Peggy Fuldar, Ryan Burnett and Dick Fording, the posted agenda also drew a complement of staffers from the Collins Pine Co. In the audience were plant manager Chris Verderber, forest manager Jay Francis and human resources manager Janice White.

  The air quality data presented by Bennitt included monthly particulate averages for Chester collected during the years 2007 – 2012.

  She described the particulate measured — called PM2.5 — as a fine-particle “transport” pollutant responsible for respiratory health issues up to and including mortality. Sources for this pollutant include motor vehicles, power plants, residential wood burning, forest fires, agricultural burning and some industrial processes.

  In looking at a chart for the six-year period, trends revealed the highest numbers occurred during wintertime inversions. Forest fires also caused severe spikes in air quality readings.

  The most intense spike occurred June 25, 2008, when California experienced a series of dry lighting strikes. This particular day’s reading was nearly off the charts at 160 ug/m3.

  Other notable spikes in Chester occurred Sept. 6, 2007, during the Moonlight Fire and again Aug. 17, 2012, during the Chips Fire.

  “The federal standard for PM2.5 is 15 ug/m3 and during the period of 2007 through 2012 the highest annual arithmetic mean was 13.4 ug/m3 for 2012,” Bennitt said.

  Her graph revealed that, excluding wildfires, the highest 24-hour value observed during this period was a reading of 65 ug/m3 reached Jan. 1, 2009.

  “Excluding wildfires, during this same six-year period there were only six days exceeding the federal 24-hour standard,” she added.

  She also clarified that the five monitoring sites operated by the air quality district use beta-attenuation monitors and said they “tend to read anywhere from 10 to 50 percent higher than federal reference PM2.5 samplers.”

  In addition to Chester, there are also monitoring sites in Portola, Quincy, Truckee and Grass Valley.

  We have a real-time 24/7 monitor located at the Chester Substation. It monitors most of the important substances and particles,” she added.

  When talking about overall air quality for Plumas County Bennitt said, “Chester is not one of our problem areas — Portola is. Although wildfires are a real serious problem in Chester, your air quality is good. You are not exceeding federal standards.”

  ABWAC member Dick Daniel questioned whether the air quality district issued health advisories and whether the vast amount of the advisories came from wildfires.

  “They only come from wildfires,” Bennitt said.

  She said the advisories routinely go to schools, hospitals and nursing homes but also said anyone interested in receiving health advisories can sign up to receive them at

  Those interested can also view the 24-hour readings from the monitoring sites by going to the website for the California Environmental Protection Agency Air Resources Board at

  Also on this website, at, information about air pollution sources, effects, prevention and control is available.


More about Bennitt

  Gretchen Bennitt began her journey at Chico State and attained a degree in biochemistry at Cal Poly, with a minor in environmental chemistry.

  She began her career in the monitoring and laboratory division working for the Air Resources Control Board at state level.

  She later worked in Montana where she learned more about the Environmental Protection Agency.

  She has been in Plumas County for 15 years.

  The Northern Sierra Air Quality Management District covers a large area and the three sub-districts of Plumas, Sierra and Nevada counties.

  The district maintains its headquarters in Grass Valley and a new office in the city of Portola.

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