Section 65. Particulate matter (PM2.5)

A. The primary and secondary ambient air quality standards for particulate matter are:

1. 15.0 micrograms per cubic meter -- annual arithmetic mean concentration.

2. 65 micrograms per cubic meter -- 24-hour average concentration.

B. Particulate matter shall be measured in the ambient air as PM_2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5 micrometers) by a reference method based on Appendix L of 40 CFR Part 50, or other method designated as such, or by an equivalent method.

C. The annual primary and secondary PM_2.5 standards are met when the annual arithmetic mean concentration, as determined in accordance with Appendix N of 40 CFR Part 50, is less than or equal to 15.0 micrograms per cubic meter.

D. The 24-hour primary and secondary PM_2.5 standards are met when the 98th percentile 24-hour concentration, as determined in accordance with Appendix N of 40 CFR Part 50, is less than or equal to 65 micrograms per cubic meter.

E. The PM_2.5 standards set forth in this section were established by EPA on July 18, 1997 (62 FR 38652) and became effective on September 8, 2004, by adoption by the board. The PM_2.5 standards set forth in this section shall continue to apply only for purposes of the following:

1. Control strategy implementation plan revisions, maintenance plans, and associated emissions budgets relative to the PM_2.5 standards in this section.

2. Designation of nonattainment areas and maintenance areas relative to the PM_2.5 standards in this section.

Nothing in this section shall prevent the redesignation of any nonattainment area to attainment at any time.

Historical Notes

Derived from Volume 20, Issue 24, eff. September 8, 2004; amended, Virginia Register Volume 23, Issue 21, eff. August 1, 2007; Volume 25, Issue 12, eff. March 18, 2009.

Statutory Authority

§ 10.1-1308 of the Code of Virginia; §§ 108, 109 and 302 of the Clean Air Act; 40 CFR Parts 50, 53 and 58.