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EPA Changes National Air Quality Standard for PM 2.5

On February 7, 2024, the Environmental Protection Agency (EPA) lowered the National Air Quality Standard for the acceptable amount of PM 2.5 levels. This change will bring the current standard from 12 to 9 micrograms per cubic meter to better align with science concerning public health. This change will go into effect late spring.

Learn more about NAAQS: (if link doesn't open, refresh link)

Learn more about the 2/7/2024 EPA ruling here: (if link doesn't open, refresh link)

Background -

With the past standard for PM 2.5 being a threshold of no greater than 12, Okanogan County has struggled to even meet that. Our area often hits PM 2.5 levels above the National Ambient Air Quality Standards (NAAQS) especially, in the years where we've seen our worst wildfires during the summer months and had reported annual PM 2.5 levels of 16 or more. Other years, where we've been fortunate to not have a wildfire blaze through the County, we've been able to reach lower numbers of PM 2.5 such as 10-12.

Daily/yearly PM 2.5 avg:

Multi-year PM 2.5 plot chart:

Multi-year PM 2.5 report:

Attainment vs. non-attainment -

To determine if an area is in attainment or not, EPA uses a three-year average. This would include the reported annual averages from the last three years to determine the PM 2.5 average for an area. Additionally, PM 2.5 data from wildfire smoke or other extraordinary events is supposed to be excluded from that average. Once that three-year average is determined, a County must meet the national standard (NAAQS) to be considered within attainment.

Failing to meet this new PM 2.5 average standard of "9", will place an area in nonattainment. From there, an area has a set amount of time to fall back into attainment, with local jurisdictions working to develop and implement plans to reduce the levels of the pollutants at issue. Failing to address those issues adequately at the local level may lead to increased sanctions by the EPA and possibly the implementation of stricter federal measures to bring air quality back to appropriate levels.

Local solutions -

Even without Okanogan County’s challenges with PM 2.5 and the Clean Air Act, air quality is a public health

issue that impacts us all, and there are collective actions that many partners in Okanogan County are working on. This includes members of the Okanogan River Airshed Partnership (ORAP). The most recent meeting was hosted by the Colville Tribes Air Quality Program. For a report of the meeting view the file below:

2023 ORAP Fall Hybrid Meeting Report.2
Download PDF • 2.63MB

As a part of the Okanogan CD Air Quality program, we frequently host chipping events to help reduce PM 2.5 levels, and to offer accessible alternatives to burning to residents in Okanogan County. Stay tuned for dates and details to participate in a spring or fall chipping event coming near.

Contact us to request a chipping event!

Dylan Streeter, or 509-422-0855


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