Section 15. Reference conditions

All measurements of air quality that are expressed as mass per unit volume (e.g., micrograms per cubic meter) other than for the particulate matter (PM_2.5) standards contained in 9VAC5-30-65, 9VAC5-30-66, and 9VAC5-30-67, and lead standards contained in 9VAC5-30-80 shall be corrected to a reference temperature of 25°C and a reference pressure of 760 millimeters of mercury (1,013.2 millibars). Measurements of PM_2.5 for purposes of comparison to the standards contained in 9VAC5-30-65, 9VAC5-30-66, and 9VAC5-30-67 and of lead for purposes of comparison to the standards contained in 9VAC5-30-80 shall be reported based on actual ambient air volume measured at the actual ambient temperature and pressure at the monitoring site during the measurement period.

Historical Notes

Derived from Volume 23, Issue 21, eff. August 1, 2007; amended, Virginia Register Volume 25, Issue 19, eff. June 24, 2009; Volume 29, Issue 17, eff. May 22, 2013.

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.