Ambient Air Monitoring Data Report
DEQ is required by EPA to compile and submit summary information for each SLAMS (State and Local Air Monitoring Station) site that is operated in the state's ambient monitoring network. Details of the information required in the report can be found in 40 CFR, Part 58, Appendix F. The Virginia Ambient Air Monitoring Data Report contains summary data compiled from monitoring stations operated by the Virginia Department of Environmental Quality, the City of Alexandria, and the Fairfax County Department of Health.
This excel spreadsheet (link above) shows the number of times in Virginia when air quality monitors have recorded ozone concentrations greater than 75 parts per billion (ppb), the health-based air quality standard measured over eight hours. "ND" indicates that no monitor was present. "Disc" indicates that the monitor at that location has been discontinued. "N/A" indicates that the monitor data for that year is not applicable to the ozone standard. In 2011, the Clean Air Status and Trends Network (CASTNET) sites, maintained by the U.S. EPA, were upgraded to meet regulatory requirements for determining ozone exceedances.