On September 28, 2026, EPA published a proposed rule reconsidering the 2024 Gasoline Distribution rule in the Federal Register. The 2024 final rule completed technology reviews of the major source NESHAP (40 CFR Part 63, Subpart R) and the area source NESHAP (Subpart BBBBBB), and it created a new NSPS for bulk gasoline terminals, 40 CFR Part 60, Subpart XXa. The reconsideration responds to 2024 petitions filed by the International Liquid Terminals Association (ILTA) and, jointly, by AFPM and API.
Most of the proposed edits are narrow. Read together, though, they say a lot about where terminal leak detection and repair (LDAR) is going. The proposal revises the XXa equipment leak compliance provisions, including compliance timing, connector monitoring, and the “no detectable emissions” language. It also adds the capital expenditure definition and calculation method that NSPS VV, VVa, and VVb use to determine modification, making XXa consistent with the other equipment leak NSPS. Comments are due November 12, 2026, under Docket ID EPA-HQ-OAR-2025-0302.
From Sight, Sound, and Smell to Instrument Monitoring
Gasoline terminals have historically handled equipment leaks through monthly sight, sound, and smell inspections. The 2024 rule replaced that approach with instrument monitoring. Under 40 CFR 60.502a(j), XXa facilities monitor pumps, valves, and connectors either quarterly with optical gas imaging (OGI) or with EPA Method 21. Under the Method 21 option, pumps and valves are monitored quarterly and connectors annually, and a reading of 10,000 ppm or greater is a leak. Subpart R at 63.424(c) cross-references these provisions at a semiannual frequency. Subpart BBBBBB at 63.11089(c) does the same at an annual frequency for bulk terminals, bulk plants, pipeline breakout stations, and pipeline pumping stations. Existing sources must meet the new requirements by May 8, 2027.
The structure will look familiar to anyone who has run a SOCMI LDAR program. XXa does not stand on its own. While some components are specifically provided for in XXa, it cross-references Subpart VVa, with caveats, for pressure relief devices (60.482-4a), sampling connection systems (60.482-5a), open-ended valves and lines (60.482-6a), and the exemptions for unsafe-to-monitor and difficult-to-monitor equipment. The repair clock (first attempt within 5 days, final repair within 15 days) and the delay-of-repair conditions follow, for the most part, the same logic chemical plants, refineries, and oil and gas facilities already use.
What the Proposal Would Change
The reconsideration moves XXa further in that direction. Key equipment leak items include:
- Capital expenditure threshold for modification (60.500a(e)(3)). EPA proposes to add the capital expenditure definition and calculation method used for modification determinations under NSPS VV, VVa, and VVb. A process improvement project costing no more than roughly 8% of the inflation-adjusted replacement cost of the affected equipment would not be treated as a modification. EPA also proposes a new definition of “process improvement.” ILTA had argued that without a threshold, a minor change such as adding a crossover line could trigger XXa.
- Connector exceptions written directly into XXa. XXa previously pointed to VVa for connector monitoring exceptions. EPA removed the connector monitoring provisions from VVa in May 2024, which left that cross-reference with nothing to point to. The proposal lists the exceptions in 60.502a(j)(1)(ii)(C) and (D) and confirms that the unsafe-to-monitor and inaccessible provisions cover all component types.
- 180 days for the first survey. Newly affected XXa facilities would have 180 calendar days to complete the first instrument survey, consistent with other equipment leak NSPS and the General Provisions. Sources subject to Subpart R or BBBBBB would instead complete the first survey by that NESHAP’s compliance date.
- Surveys during active loading. Instrument monitoring would need to be done while gasoline is being loaded into a cargo tank, so that the vapor collection and control systems are actually under vapor load.
- Pre-performance test screening. The phrase “operated with no detectable emissions” in 60.503a(a)(2) would become “has no leaks at or above an instrument reading of 500 ppmv.” EPA describes this as a work practice standard rather than an operating limit. Leaks found must be repaired before the test, and delay of repair would not apply. This is a departure from how “no detectable emissions” works elsewhere. In other LDAR and closed vent system requirements, no detectable emissions (generally an instrument reading below 500 ppm above background) is a limit that applies at all times unless the regulation provides otherwise, and EPA’s recent BWON enforcement has treated failed no detectable emissions readings as noncompliance.
- “In gasoline service.” The definition would change from equipment “used in a system that transfers” gasoline to equipment that “contains or contacts” gasoline or gasoline vapors. Backup control systems would require periodic instrument monitoring only when they are actually handling vapors.
EPA did not propose to drop annual instrument monitoring at bulk gasoline plants and pipeline pumping stations, as ILTA had requested. The agency is taking comment on alternatives, including a performance-based skip to every two years, a return to monthly sensory inspections, or relief limited to “small” or “remote” pumping stations.
The Capital Expenditure Threshold Comes With a Tracking Burden
Of all the proposed changes, the modification threshold may have the largest practical impact on day-to-day operations. On paper it is relief: small projects stay out of XXa. In practice, a facility can only rely on that relief if it can show where each project falls relative to the threshold. That means establishing the replacement cost of the affected equipment, applying the CPI adjustment, capturing the cost of each physical or operational change, and keeping documentation that will hold up in an inspection or permit review.
Very few terminals track capital spending this way today. Project costs typically sit in engineering and accounting systems that were never set up to answer an NSPS applicability question, and environmental staff are often not involved until after a project is scoped. Facilities subject to NSPS VV, VVa, and VVb already make these determinations, though many find the documentation burden significant. For terminals, the change would be new, and it would apply across tank farm, loading rack, and vapor system projects of every size.
Facilities that do not build this tracking in early risk two outcomes. One is treating a project as exempt without the records to support it. The other is treating every project as a potential modification and taking on XXa requirements and permitting delays that the threshold was meant to avoid.
Part of a Larger Pattern: Harmonization and Tightening
Two trends run through this proposal and EPA’s other recent equipment leak rulemakings.
The first is harmonization. The VV family of rules is becoming the template for equipment leak language across source categories. The AFPM and API petition specifically asked EPA to harmonize the XXa provisions with other NSPS, and the capital expenditure definition, connector exceptions, and 180-day survey window all borrow directly from that framework.
The second is tightening. The 2024 SOCMI amendments, including the HON updates and the new NSPS VVb, which applies to SOCMI equipment constructed, reconstructed, or modified after April 25, 2023, lowered leak definitions to 100 ppm for valves and 500 ppm for connectors and added connector monitoring. Gasoline distribution moved from sensory inspections to instrument monitoring in the same year. The 2026 proposal adds procedural flexibility, but it does not walk back instrument monitoring itself. Terminals currently use a 10,000 ppm leak definition, and the chemical sector precedent is worth keeping in mind as future reviews come up.
What Terminal Operators Should Be Doing Now
With the May 2027 compliance date about 18 months away, facilities subject to Subparts R, BBBBBB, or XXa should consider:
- Building or validating a component inventory and tagging program for equipment in gasoline service, including vapor collection and processing systems and loading arms.
- Choosing between OGI and Method 21, and checking that the monitoring frequency matches the applicable subpart.
- Setting up an LDAR database or recordkeeping system that can track repair deadlines, delay of repair, and semiannual reporting.
- Setting up a capital expenditure tracking process that links engineering and accounting project data to XXa applicability, and reviewing recent and planned projects against the proposed threshold.
- Evaluating whether the proposed changes affect current Title V permit terms or planned permit applications.
Sites that already operate chemical plant LDAR programs may be able to adapt existing procedures and software. Standalone terminals are more likely to be building these programs for the first time.
Trinity’s Chemical Sector Services group supports equipment leak compliance across chemical manufacturing, oil and gas, refining, and tanks and terminals, including LDAR program development, applicability reviews, and regulatory comment preparation. Trinity has also developed a capital expenditure tracking tool that facilities can implement to document project costs against modification thresholds such as those in NSPS VV, VVa, VVb, and proposed NSPS XXa. Terminal staff looking for broader training can register for Trinity’s LDAR for Tanks & Terminals. For assistance evaluating how the proposal affects your facility or preparing comments before the November 12 deadline, please contact Inaas Darrat.
