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Clean Air Status and Trends Network (CASTNET)

CASTNET is a national monitoring network established to assess trends in pollutant concentrations, atmospheric deposition, and ecological effects due to changes in air pollutant emissions. See the CASTNET overview fact sheet and the CASTNET Ozone Monitoring page for more information.

What's New

  • EPA has suspended operations of a number of CASTNET locations throughout the country for the remainder of the fiscal year due to budget constraints. These sites include: ASH135, UND002, WST109, HWF187, CDR119, PSU106 (ozone continues), CDZ171, PNF126, ANA115 (ozone continues), DCP114, and SAN189 (ozone continues).

  • The National Park Service established a new ozone CASTNET site in Carlsbad Caverns National Park, NM in March 2021 (CAV436).

  • In partnership with the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), EPA established the 7th CASTNET tribal site in November 2020. The UMA009 CASTNET site is co-located with NADP/AMoN (WA04).

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