The EPA established a health based standard (National Ambient Air Quality Standard, (NAAQS)) for fine particulate matter (PM2.5), which is a byproduct of combustion. The 24 hour PM2.5 standard is based on the 98th percentile averaged over 3 years. The graph below shows the 98th percentiles and design values as measured since 2000 for Fairbanks and North Pole. An area is in violation of the NAAQS when the Design Value is greater than the 24 hour NAAQS for PM2.5, which is currently set at 35 µg/m3. EPA used data from the State Office Building Monitor in Fairbanks to classify the area as nonattainment. The design value for the Nonattainment Area for 2017-2020 is 64 µg/m3 based on data from the North Pole Hurst Road Monitor (formerly North Pole Fire Station #3).
Note: The vertical axis of this chart extends to 200 µg/m3. The PM2.5 concentrations represent the concentration at local conditions and have not been corrected for local temperature and pressure
PM2.5 24-Hour Design Values 2020-2023
2020
2021
2022
2023
NCore 98thPercentile
26.6
27.5
76.3 (29.11)
30.7 (201)
NCore 24-Hr Design Value
37 (271)
38 (27.31)
44 (281)
45 (261)
A Street 98thPercentile
36.1
N/A2
N/A2
34.4 (27.81)
A Street 24-Hr Design Value
--
N/A3
N/A3
N/A3
North Pole 98thPercentile
71.4
65.5
72.5 (51.21)
62.5 (51.91)
North Pole 24-Hr Design Value
68 (631)
72 (67.31)
70 (631)
67 (561)
PM2.5 Annual Design Values 2020-2023
2020
2021
2022
2023
NCore Annual Design Value
8.3
8.5 (7.91)
8.8 (7.31)
9.2 (6.91)
A Street Annual Design Value
--
9.6
N/A3
N/A3
North Pole Annual Design Value
13
13.2 (11.81)
12.2 (10.71)
12.1 (9.51)
1The number in parentheses indicates the value when exceedance days caused by wildland fire smoke are excluded from the calculation.
2The site did not meet the required data capture; therefore, a 98th percentile cannot be calculated.
3A design value cannot be calculated due to a lack of sufficient data.
Glossary
Glossary
NAAQS
National Ambient Air Quality Standard - A health-based air quality standard set by EPA based on a review of available scientific information. NAAQS exist for criteria pollutants including Particulate Matter (PM2.5 and PM10), Carbon Monoxide (CO), Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2), Ozone(O3), and Lead(Pb).
A three-year average of the 98th percentile value. An area is in violation of the NAAQS when the Design Values is greater than the 24-hour NAAQS for PM2.5, which is currently set at 35 µg/m340 CFR 50 Appendix N - see section 4.5(b)
Clean Data Year
A year when the 98th percentile value is less than the NAAQS.
Exceptional Events
Unusual or naturally occurring events that can affect air quality but are not reasonably controllable.
24-Hour: 98th percentile, averaged over 3 years, must be below the standardAnnual: Annual arithmetic mean, averaged over 3 years, must be below the standard. 40 CFR 50 Appendix N - see sections 4.1 and 4.2
