What EPA Is Reviewing

EPA will reconsider Texas classifications under the 2015 ozone National Ambient Air Quality Standards, including San Antonio’s status, and the 2008 ozone status of Houston-Galveston-Brazoria and Dallas-Fort Worth. It will also revisit its 2022 disapproval of a Texas Section 179B demonstration addressing emissions transported from outside the United States. EPA has not determined the outcomes.

The current classifications provide context for the review. TCEQ lists the following ozone designations; the September announcement does not replace them.

County boundaries differ by standard. Liberty and Waller counties are in the Houston area’s 2008 nonattainment area, but not its 2015 area. Rockwall County is in the Dallas-Fort Worth 2008 area, but not its 2015 area. The San Antonio 2015 nonattainment designation applies to Bexar County.

International Emissions and Attainment Are Different Questions

Section 179B(b) allows a state to demonstrate that an ozone area would have met its attainment deadline if emissions from outside the United States had not affected its air quality. If EPA accepts that demonstration, the area is exempt from the mandatory reclassification provision for failure to attain. The area can remain designated nonattainment.

EPA’s March 2026 Phoenix-Mesa decision illustrates the distinction. The agency accepted an international emissions demonstration and kept the area at moderate nonattainment, avoiding a higher classification. It did not redesignate the area to attainment. That decision offers context for the Texas review, rather than a prediction of its outcome.

A formal redesignation to attainment under Section 107(d)(3)(E) requires EPA to determine that the standard has been attained. Other criteria include an approved implementation plan, air quality improvement resulting from permanent and enforceable emissions reductions, an approved maintenance plan, and fulfillment of applicable Clean Air Act requirements.

TCEQ also submitted a new Section 179B(b) demonstration for Bexar County on July 2, 2026. That submission is a request for EPA review; it does not change the county’s designation.

Potential Effects on Power and Oil and Gas Projects

Ozone classifications affect when a facility becomes a major source and the requirements for construction or expansion. Nonattainment New Source Review can require stringent emissions controls and offsets, which are qualifying emissions reductions used to compensate for new emissions.

TCEQ’s guidance lists a 25-ton-per-year major source threshold for nitrogen oxides and volatile organic compounds (VOC) in severe ozone areas, compared with 50 tons per year in serious areas. Applicability considers emissions or potential to emit. Minimum offset ratios are 1.30 to 1 and 1.20 to 1, respectively. These are classification examples, not changes EPA has announced for Texas.

If the final actions change the applicable classification or designation, some projects could face different thresholds or offset obligations. For power generators and oil and gas facilities with combustion equipment or VOC emissions, that could affect project costs and permit planning. This is a potential implication of the permitting framework; EPA has not established project savings or faster approvals.

The effect also depends on both ozone standards. TCEQ directs applicants to use the more stringent requirement when two standards apply. Relief under the 2015 standard alone may therefore leave requirements under the 2008 standard in place.

Encino Perspective

EPA’s review could create opportunities to reduce permitting costs or reconsider planned expansions in affected Texas counties. The value for any facility will depend on which requirements change and whether another ozone standard or existing permit condition continues to impose the same obligation.

We recommend identifying those dependencies now. Confirm the county’s classification under both ozone standards, determine which requirements rely on that classification, and keep emissions calculations and equipment specifications current. This preparation can help project teams assess a final EPA action and determine whether it changes their permitting options.

Facilities should continue following current authorizations while the review proceeds. Before revising construction schedules or compliance plans, confirm the final action’s effective date, any necessary state implementation or permit changes, and the permitting requirements that apply afterward. A redesignation to attainment may change the review process while leaving other emissions control, testing, monitoring, and reporting obligations in place.

Encino Environmental Services supports air permitting, regulatory applicability reviews, and emissions testing and monitoring. Our team can help owners assess how a final EPA action affects their facility and identify the obligations that continue to apply.