Why is this important?
The Clean Air Act identifies two types of national ambient air quality standards. Primary standards provide public health protection, including protecting the health of sensitive populations such as people with asthma, children, and the elderly. Secondary standards provide public welfare protection, including protection against decreased visibility and damage to animals, crops, vegetation, and buildings.
|Ozone||Primary & Secondary||8 hours||0.075 ppm||Annual fourth-highest daily maximum 8-hr concentration, averaged over 3 years|
|Particulate Matter (PM2.5)||Primary||Annual||12 μg/m3||Annual mean, averaged over 3 years|
|Secondary||Annual||15 μg/m3||Annual mean, averaged over 3 years|
|Primary & Secondary||24 hours||35 μg/m3||98th percentile, averaged over 3 years|
|Particulate Matter (PM10)||Primary & Secondary||24 hours||150 μg/m3||Not to be exceeded more than once per year on average over 3 years|
|Carbon Monoxide||Primary||8 hours||9 ppm||Not to be exceeded more than once per year|
|Primary||1 hour||35 ppm||Not to be exceeded more than once per year|
There are two air quality monitoring stations in Thurston County monitoring ozone and fine particulate matter (PM 2.5). The region’s air quality has continued to meet air quality standards over the last 15 years.