Section 176 of the federal Clean Air Act requires that federally funded or approved plans, programs and projects conform with state or federal air quality implementation plans.
The criteria and procedures governing the determination of conformity in nonattainment and maintenance areas are located in Subpart T of 40 CFR Part 51 for all federally-funded transportation plans, programs and projects and in Subpart W of 40 CFR Part 51 for general (non-transportation) plans, programs, and projects. States must establish conformity criteria and procedures consistent with EPA's regulations.
In Virginia, the federal conformity requirements are implemented under the Regulation for Transportation Conformity and the Regulation for General Conformity. These regulations are approved as part of Virginia's State Implementation Plan (SIP). Conformity in Virginia originally applied in the Northern Virginia, Fredericksburg, Richmond, and Hampton Roads nonattainment/maintenance areas. Since the original conformity requirements were implemented, EPA has issued more restrictive ozone standards, and the Fredericksburg, Richmond and Hampton Roads areas have attained those standards.
EPA's most recent ozone implementation rules remove the conformity requirement for standards that have been revoked; thus far, the 1-hour ozone standard of 0.012 parts per million (ppm) and the 8-hour ozone standard of 0.08 ppm have been revoked. This means that federal facilities in the Fredericksburg, Richmond and Hampton Roads areas do not need to conduct transportation or general conformity reviews. Transportation and general conformity are still required in the northern Virginia area until the area's attainment status and EPA's ozone rules change.
For more information about transportation conformity, contact Sonya Lewis-Cheatham. For more information about general conformity, contact Tom Ballou.