On September 28, 2026, the U.S. Environmental Protection Agency (U.S. EPA) published a proposal that affects the following standards:
- 40 CFR Part 60, Subpart XXa – Standards of Performance for Bulk Gasoline Terminals that Commenced Construction, Modification, or Reconstruction after June 10, 2022 (NSPS Subpart XXa)
- 40 CFR Part 63, Subpart R – National Emissions Standards for Gasoline Distribution Facilities (Bulk Gasoline Terminals and Pipeline Breakout Stations) (NESHAP Subpart R)
- 40 CFR Part 63, Subpart BBBBBB – National Emissions Standards for Hazardous Air Pollutants for Source Category: Gasoline Distribution Bulk Terminals, Bulk Plants, and Pipeline Facilities (NESHAP Subpart 6B)
The Federal Register notice requests comments on the proposed action and asks industry representatives for additional data that may improve U.S. EPA’s analysis. Comments on the proposed rule must be submitted by November 12, 2026. Background on these rules and a description of the proposed revisions are provided below.
Background
On May 8, 2024, U.S. EPA promulgated NSPS Subpart XXa and published revisions to NESHAP Subpart R and NESHAP Subpart 6B in what was referred to as the “2024 Final Rule” following the gasoline distribution rules technology review. U.S. EPA received three petitions on the final rules and began a voluntary reconsideration of the rule in 2025. The proposed rules and requests for comments identified in the September 28, 2026, publication are the result of U.S. EPA’s reconsideration of the rules.
What is not proposed to change?
U.S. EPA is not proposing new emissions limits or changes to the compliance dates established in the 2024 Final Rules. However, U.S. EPA is soliciting comments on the compliance dates.
U.S. EPA is not proposing to change the previous load assumption, which requires facilities to assume that a cargo tank held gasoline if the previous contents are unknown. Petitioners had requested the assumption be revised to assume the same contents as what is currently being loaded into the cargo tank because “switch loading” is uncommon and obtaining records of previous tank loads is difficult. However, U.S. EPA determined that revising this assumption is not sufficiently protective and would disincentivize operators from trying to learn the previous contents of the cargo tank. U.S. EPA has not proposed changes to requirements when the previous load of the cargo tank is known.
U.S. EPA is not proposing to revise the annual instrument monitoring requirements for bulk gasoline plants and pipeline pumping stations under NESHAP Subpart 6B because it was not determined to be cost prohibitive. However, U.S. EPA is soliciting comments and supporting data for potential alternative monitoring requirements. This may include adding alternative monitoring requirements that allow for a skip period, reverting to monthly audio, visual, or olfactory (AVO) inspections, or establishing less stringent monitoring requirements for facilities that are “small” or “remote” and establishing definitions for these terms.
What are the proposed changes?
Under NSPS Subpart XXa, NESHAP Subpart R, and NESHAP Subpart 6B, U.S. EPA is proposing to revise the definition of “in gasoline service”. The current definition suggests that any equipment and control system that could be used during the transfer of gasoline or gasoline vapors is a system “in gasoline service” and is subject to the requirements of these rules. U.S. EPA proposes a clarification to the definition that equipment and control systems must “contain or contact” gasoline or gasoline vapors to meet the definition of “in gasoline service”. This clarification will eliminate unnecessary monitoring and inspection requirements for systems that are not active and not anticipated to be a source of emissions.
Under NSPS Subpart XXa, U.S. EPA is proposing to add a capital expenditure threshold for modification that is similar to other equipment leak rules (e.g., NSPS Subpart VV, VVa, and VVb) and add a definition of “process improvements”. These changes prevent small process improvement projects from triggering the definition of a modification (which would trigger NSPS Subpart XXa applicability) and allow facilities operational flexibility in implementing projects. U.S. EPA is seeking feedback on both the capital expenditure threshold and proposed definition of “process improvements”.
In addition, a significant number of revisions are proposed for NSPS Subpart XXa to provide clarifications to definitions, deadlines, monitoring requirements, work practice standards, etc. While most of these revisions are made directly in NSPS Subpart XXa, there are cascading effects to NESHAP Subpart R and NESHAP Subpart 6B, which reference requirements in NSPS Subpart XXa. Some of the proposed changes to NSPS Subpart XXa include:
- Clarifying that the first instrument monitoring survey for equipment leaks must be conducted within 180 calendar days of becoming subject to the equipment leak monitoring requirements in NSPS Subpart XXa. However, if the instrument monitoring survey for equipment leaks is required by another subpart, then the compliance date for the first survey is established based on the cross-referencing subpart [40 CFR 60.502a(j)(1)]. NESHAP Subpart R and NESHAP Subpart 6B both cross-reference the NSPS XXa requirements for the instrument monitoring survey for equipment leaks and establish a compliance date of May 8, 2027, for the first survey.
- Clarifying that the instrument monitoring surveys for equipment leaks must be conducted while actively loading gasoline [40 CFR 60.502a(j)(1)]. This clarification was previously included in the pre-performance test monitoring requirements but was not provided for routine instrument monitoring surveys. NESHAP Subpart R and NESHAP Subpart 6B cross-reference this requirement.
- Clarifying that a leak detected during pre-performance test inspections is not a violation of the equipment leak work practice standards, the leak must be repaired prior to the performance test with no delay of repair allowed, and a leak is defined as an instrument reading ≥ 500 parts per million by volume (ppmv) [40 CFR 60.503a(a)(2)]. NESHAP Subpart R and NESHAP Subpart 6B cross-reference this requirement.
Finally, U.S. EPA proposed and requested feedback on changes to operating limits and monitoring requirements for emissions control devices. Some of the proposed changes include:
- Revising the method of establishing and monitoring the temperature for thermal oxidation systems. U.S. EPA has proposed two compliance options. One option allows facilities to complete testing during a broader range of operating scenarios to establish a site-specific minimum temperature, while the other option specifies a minimum mid-stack temperature.
- Establishing a maximum air assist rate operating parameter and daily visual inspection requirements for air-assisted flares and thermal oxidizers.
- Revising the sample frequency for net heating value testing of flare gas streams/systems. Instead of collecting 14 daily grab samples over two weeks, facilities will be allowed to collect multiple grab samples per day as long as there is at least 20 minutes between samples (the approximate time needed to load a typical cargo tank).
- Reverting vapor recovery system operating limits to be on a 6-hour rolling average instead of the 3-hour rolling average identified in the 2024 Final Rules.
- Reverting vapor tightness testing requirements for gasoline cargo tanks to the previous rule requirements because of U.S. EPA Method 27 sensitivity limitations.
What’s next?
U.S. EPA’s publication identifies 20 different revisions or proposed requirements on which they are specifically seeking feedback. ALL4 can help you evaluate the impacts of the revisions and proposed requirements to your facility and assist with providing feedback directly to U.S. EPA. Reach out to Stacy Arner-Jenkins at sarner@all4inc.com or Tegan Conner at tconner@all4inc.com with any questions!
