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Juneau State Office Mailing Address Update

All mail sent to the DEC office in Juneau through the U.S. Postal Service must be addressed to P.O. Box 111800. Beginning October 1, all mail addressed to our Willoughby Avenue address will not be delivered and will be returned to sender by the Post Office. This change only impacts incoming mail to the Juneau office.

Mat-Su - Butte - PM2.5

The Butte area of the Matanuska-Susitna Borough has experienced elevated levels of fine particulate matter (PM2.5). Air quality monitoring data indicates that the area may exceed the PM2.5 National Ambient Air Quality Standard (NAAQS) of 35 micrograms/cubic meter. If the area continues to experience elevated levels of PM2.5, EPA may designate the area as a nonattainment area. Information on this page can help residents understand the issue and learn what actions they can take to improve air quality.

Butte area

(Photo Taken December 14, 2014 (24-Hr PM2.5 Average = 51.21 µg/m3))

98th Percentile PM2.5 24-hr Average Concentration, µg/m3 2015 2016 2017 Design Value Cannot Exceed*
37.9 29.2 26.2 31.1 35.4

*Compliance with the 24-hr PM2.5 National Ambient Air Quality Standard (NAAQS) is determined using three years of air monitoring data. The design value (DV) is an average of 98th percentile 24-hr average PM2.5 concentrations over three years. The 2014-2016 DV is 35.1 µg/m3. The NAAQS is currently 35 µg/m3, an area is considered to violate the standards if the DV is 35.5 µg/m3 or above.