The Air Check Virginia program ensures that vehicles operate as cleanly as possible.

Established in 1982, the program is an important part of Northern Virginia's air quality plan, ensuring a continuing rise in clean air days. Vehicle emissions are the largest single source of toxic and smog-forming air pollution in Northern Virginia and much of the rest of the country.

Emission inspections are required for certain vehicles registered or operated primarily in Northern Virginia, including the counties of Arlington, Fairfax, Loudoun, Prince William and Stafford, and the cities of Alexandria, Fairfax, Falls Church, Manassas and Manassas Park.

Vehicles must receive a passing emission inspection or receive a waiver in order to register or renew registration with the Virginia Department of Motor Vehicles. 

Air Check Virginia also operates on-road emission testing, which checks emissions levels while vehicles are on the road. It identifies vehicles with high emissions so owners can be notified by mail and necessary repairs can be made.

DEQ certifies and permits emissions inspection stations and repair facilities. The agency licenses emissions inspectors and certifies repair technicians, who successfully complete the required training.