NNPH Air Quality Management Division Seeks Comment on Exceptional Events Demonstrations

Oct 26, 2023

Reno/Sparks, Nevada.  Oct. 26, 2023 – Northern Nevada Public Health – Air Quality Management Division (AQMD) is requesting written public comment on the 2021 and 2022 PM10 Exceptional Events Demonstrations, a series of technical reports proving that wildfires caused some poor air quality conditions, specifically PM10, in 2021 and 2022. The documents request that EPA exclude that data from regulatory consideration. PM10 is defined as particulate matter that is sized 10 microns in diameter or less and is one of the many air pollutants found in wildfire smoke.

If the EPA agrees to exclude that data, it means that future air quality plans for local emission sources are not affected by PM10 found in wildfire smoke. Excluding this data does not eliminate the public health impacts or AQMD’s role in notifying the public of poor air quality.

AQMD’s 2nd 10-Year PM10 Maintenance plan is due to EPA next year. In order for EPA to approve this plan, the maintenance area must not be violating the 24-Hour PM10 National Ambient Air Quality Standard (NAAQS). Multiple wildfires in 2021 and 2022 caused fifteen (15) exceedances of the PM10 NAAQS within the Truckee Meadows PM10 maintenance area. Through the Exceptional Events Rule (40 CFR 50.14), AQMD can request that data influenced by wildfires be excluded when determining compliance with the 24-Hour PM10 NAAQS.

The demonstrations are broken down into four separate events:

2021 Dixie/Tamarack Fire Event

2021 Dixie/Antelope Fire Event

2021 Dixie/Caldor Fire Event

2022 Mosquito Fire Event

Comments will be accepted until midnight on November 26, 2023, and may be submitted via e-mail to


All correspondence must include first and last name and a complete mailing address.

For more information regarding the Health District’s air quality efforts, visit the Air Quality Management Division’s website at OurCleanAir.com.

NOTE: The Washoe County Health District became Northern Nevada Public Health on Aug. 31, 2023. Materials developed prior to that date may contain Washoe County Health District brand, logos, and references.

Northern Nevada Public Health (NNPH) is nationally accredited by the Public Health Accreditation Board and has jurisdiction over all public health matters in Reno, Sparks, and Washoe County through the policy-making District Board of Health. NNPH consists of five divisions: Administrative Health Services, Air Quality Management, Community and Clinical Health Services, Environmental Health Services and Epidemiology & Public Health Preparedness. More info can be found here.