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.
Alert
Suspension Notice
EPA has suspended operations of a number of CASTNET locations throughout the country for the remainder of the fiscal year due to budget constraints.