The U.S. Environmental Protection Agency (EPA) has approved Alabama's updated process for determining whether federally supported transportation plans and projects are consistent with the state's air-quality obligations. Published September 24, the final rule replaces Alabama's existing transportation conformity agreement with updated procedures covering agency consultation, conflict resolution, public participation and enforcement of transportation-related control and mitigation measures. The rule takes effect October 26.
The approval does not establish a new emissions limit or change requirements for stationary-source air permits. Its practical effect is to update the process transportation agencies must follow when demonstrating that highway and transit investments will not interfere with applicable air-quality plans, a procedural focus similar to how conformity obligations have tightened in other metro areas without changing underlying emissions limits.
Birmingham Agencies Receive Clearer Responsibilities
Transportation conformity applies to federally funded or approved highway and transit plans, transportation improvement programs and individual projects in areas that do not meet, or are maintaining, national air-quality standards. The Alabama agreement applies primarily to the Birmingham region, covering Jefferson and Shelby counties for the former 1997 ozone nonattainment area and Jefferson, Shelby and part of Walker County for the 2006 24-hour fine-particle maintenance area.
Under the revised memorandum of agreement, the Birmingham Metropolitan Planning Organization, Alabama DOT, Alabama Department of Environmental Management, Jefferson County Department of Health and federal transportation and environmental agencies must coordinate before making conformity determinations. The update further defines the Birmingham MPO's responsibilities for transportation control measures and requires Alabama DOT to provide the MPO with current vehicle-miles-traveled and traffic data used in the analysis. Jackson County, previously covered alongside Jefferson and Shelby counties, was removed because the area is no longer subject to the conformity requirements addressed by the revised framework.
Mitigation Commitments Become Federally Enforceable
The revised agreement requires written commitments before agencies rely on certain control or mitigation measures to make a conformity determination. If a control measure is not already included in the applicable transportation plan and improvement program, the commitment must be documented before the conformity finding, and project-level mitigation measures require the same written commitment from sponsors.
This matters when a project's emissions analysis depends on measures such as operating restrictions or traffic-management provisions intended to reduce air-quality effects. Once used to support conformity, those commitments become part of the enforceable project framework rather than optional planning assumptions, a shift toward public accountability that echoes how EPA has made more of its own compliance data directly accessible to outside reviewers. No transportation plan, improvement program or project may receive a conformity finding without the required public-involvement process and public access to the underlying data.
Procedural Gaps, Not New Emissions Limits, Are the Real Exposure
For transportation agencies and project sponsors, the principal exposure is procedural. Incomplete traffic data, poorly documented mitigation commitments or unresolved agency disagreements can interfere with the conformity finding a federally supported project needs, a risk that grows in any metro area juggling multiple nonattainment or maintenance designations, as ongoing litigation over the current fine-particle standard continues to demonstrate nationally.
EPA determined that the revision complies with the Clean Air Act and does not impose requirements beyond Alabama law, and concluded the action is not a major rule and will not significantly affect a substantial number of small entities. EPA received one supportive comment and one comment outside the rulemaking's scope, so the final action adopts the framework proposed in July without a substantive policy change.
Petitions seeking judicial review must be filed by November 23. Unless challenged, the updated procedures join Alabama's federally approved air plan on October 26.
