9VAC5-30-68. Particulate matter (PM2.5).
A. The national primary ambient air quality standards for PM2.5 are 9.0 micrograms per cubic meter (µg/m3) annual arithmetic mean concentration and 35 µg/m3 24-hour average concentration measured in the ambient air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5 micrometers) by either:
1. A reference method based on Appendix L to 40 CFR Part 50 and designated in accordance with 40 CFR Part 53; or
2. An equivalent method designated in accordance with 40 CFR Part 53.
B. The primary annual PM2.5 standard is met when the annual arithmetic mean concentration, as determined in accordance with Appendix N to 40 CFR Part 50, is less than or equal to 9.0 µg/m3.
C. The primary 24-hour PM2.5 standard is met when the 98th percentile 24-hour concentration, as determined in accordance with Appendix N to 40 CFR Part 50, is less than or equal to 35 µg/m3.
Statutory Authority
§ 1-.1-1308 of the Code of Virginia; Clean Air Act §§ 108, 109, 302; 40 CFR 50.20, 40 CFR Part 53, 40 CFR Part 58.
Historical Notes
Derived from Virginia Register Volume 41, Issue 1, eff. September 25, 2024.