Section 1635. Ambient air increments

In areas designated as class I, II or III, increases in pollutant concentration over the baseline concentration shall be limited to the following:

MAXIMUM ALLOWABLE INCREASE (micrograms per cubic meter)
Class I Area
PM2.5:
Annual arithmetic mean	1
24 hour maximum	2
PM10:
Annual arithmetic mean	4
24 hour maximum	8
Sulfur dioxide:
Annual arithmetic mean	2
24-hour maximum	5
Three-hour maximum	25
Nitrogen dioxide:
Annual arithmetic mean	2.5
Class II Area
PM2.5:
Annual arithmetic mean	4
24 hour maximum	9
PM10:
Annual arithmetic mean	17
24 hour maximum	30
Sulfur dioxide:
Annual arithmetic mean	20
24-hour maximum	91
Three-hour maximum	512
Nitrogen dioxide:
Annual arithmetic mean	25
Class III Area
PM2.5:
Annual arithmetic mean	8
24 hour maximum	18
PM10:
Annual arithmetic mean	34
24 hour maximum	60
Sulfur dioxide:
Annual arithmetic mean	40
24-hour maximum	182
Three-hour maximum	700
Nitrogen dioxide:
Annual arithmetic mean	50

For any period other than an annual period, the applicable maximum allowable increase may be exceeded during one such period per year at any one location.

Historical Notes

Derived from Volume 22, Issue 23, eff. September 1, 2006; amended, Virginia Register Volume 27, Issue 23, eff. August 17, 2011.

Statutory Authority

§ 10.1-1308 of the Code of Virginia; Clean Air Act (§§ 110, 112, 165, 173, and 182 and Title V); 40 CFR Parts 51, 61, 63, 70 and 72.