Virginia Administrative Code
Title 9 - ENVIRONMENT
Agency 5 - STATE AIR POLLUTION CONTROL BOARD
Chapter 91 - REGULATIONS FOR THE CONTROL OF MOTOR VEHICLE EMISSIONS IN THE NORTHERN VIRGINIA AREA
Part III - Emission Standards for Motor Vehicle Air Pollution
Section 9VAC5-91-170 - Exhaust emission standards for ASM testing in enhanced emissions inspection programs

A. No motor vehicle shall discharge carbon monoxide (CO), hydrocarbons (HC), or oxides of nitrogen (NOX) in its exhaust emissions in excess of standards set forth in tables in Part XIV (9VAC5-91-790 et seq.) when measured with a certified analyzer system and in accordance with the ASM inspection procedures prescribed in Part VI (9VAC5-91-410 et seq.).

B. The director may determine, based on results of emissions inspections verified by the department and in consultation with vehicle manufacturers, EPA or appropriate research organizations that emissions standards for specific vehicle models, model years, or weight classifications shall remain at the phase-in level as specified in 9VAC5-91-790 or be set at interim standards less stringent than the final standards rather than being adjusted to the final standards specified in 9VAC5-91-800.