Air Quality

General
Local governments (LGs) must comply with the
Clean Air Act
(CAA), the
National Environmental Policy Act
(NEPA) and the Federal-Aid Highways Code (
23 U.S.C. §§101-190
) for potential project effects on air quality. The CAA prohibits federal agencies from providing funding or approving any activity not conforming to an applicable state implementation plan (SIP). An environmental decision cannot be made for any project in a nonattainment and maintenance area subject to transportation conformity, until project level transportation conformity is demonstrated. Incorporating the LG project into the Statewide Transportation Improvement Program, Transportation Improvement Program and/or Metropolitan Transportation Plan early in project development will help prevent project delays.
Federal Requirements
  1. 40 CFR Part 93
    – Provides Environmental Protection Agency regulations implementing transportation conformity that require non-exempt projects in certain nonattainment or maintenance areas to be consistent with the SIP.
  2. 23 CFR §450.322
    – Provides FHWA regulations implementing
    23 U.S.C. §134
    for the congestion management process. In order for federal funds to be programmed for projects adding single occupant vehicle capacity in certain nonattainment areas, the project must be addressed in a congestion management process.
  3. FHWA uses guidance rather than rule to establish requirements for air quality analyses, and these are discussed in the
    TxDOT Environmental Handbook for Air Quality
    and are subject to periodic revision.
State Requirements
  1. 43 TAC Part 1, Chapter 2, Subchapter I
    – Requires documentation of compliance with air quality provisions under the memorandum of understanding (MOU) with the Texas Commission on Environmental Quality (TCEQ).
  2. 30 TAC §114.260
    – Implements state requirements for transportation conformity.
Required Practices
Compliance responsibilities vary depending on the scope of the project and the potential social, economic and environmental impacts. The
LGPM Guide
provides details on the process used to achieve compliance for air quality regulations.