
Gasoline Distribution Facility Air Quality Compliance
Gasoline distribution facilities are facing new air quality compliance requirements for emissions monitoring, leak detection, recordkeeping, and reporting, with important federal compliance deadlines approaching in 2027. Updates to NESHAP Subpart 6B (40 CFR Part 63, Subpart BBBBBB), Appendix K, and NSPS Subpart XXa introduce new or expanded requirements for optical gas imaging (OGI), leak detection and repair (LDAR), emissions monitoring, inspections, recordkeeping, and reporting.
Trihydro provides nationwide air quality compliance support for gasoline distribution facilities, including bulk gasoline terminals and pipeline breakout stations. Our services range from regulatory applicability and compliance assessments to Appendix K OGI inspections, Method 21 monitoring, LDAR program implementation, and ongoing compliance documentation and reporting.
Air Quality Requirements for Gasoline Distribution Facilities
Appendix K, NESHAP Subpart 6B, and NSPS Subpart XXa address different aspects of gasoline distribution facility compliance, and applicability depends on factors including facility type, equipment, operations, and construction or modification history. Understanding which requirements apply is the first step in developing an effective monitoring and compliance program.
Trihydro works with facility operators to evaluate regulatory applicability, identify compliance gaps, and implement the monitoring, recordkeeping, and documentation programs needed to meet applicable requirements and prepare for upcoming compliance deadlines.

Appendix K (40 CFR Part 60, Appendix K) establishes a standardized methodology for conducting optical gas imaging (OGI) inspections using infrared cameras. The protocol addresses camera performance, operator qualifications and training, senior OGI operator oversight, operating envelopes, monitoring plans, quality assurance, survey documentation, and recordkeeping.
Appendix K is not a standalone regulation. It applies when incorporated by a referencing regulatory subpart and provides the framework for OGI-based leak detection requirements. Facilities subject to Appendix K must conduct and document OGI inspections in accordance with the protocol and applicable regulatory requirements.
Trihydro helps facilities develop and implement Appendix K-compliant OGI monitoring programs, providing qualified personnel, technical expertise, and data management support for ongoing inspection and documentation requirements.
Trihydro’s Appendix K compliance services include:
- Appendix K applicability evaluations
- Appendix K monitoring plan development
- Appendix K OGI inspections and surveys
- Certified thermographer services
- Senior OGI operator support
- OGI operator qualification and training support
- Compliance documentation and recordkeeping
- LeakTracker Pro® data management and reporting
- Regulatory audit and program review support

NESHAP Subpart 6B (40 CFR Part 63, Subpart BBBBBB), commonly referred to as the gasoline distribution NESHAP, establishes national emission standards for hazardous air pollutants (HAPs) for gasoline distribution bulk terminals, bulk plants, and pipeline facilities. Requirements address gasoline storage tanks, loading operations, equipment leak inspections, testing and monitoring, recordkeeping, and reporting.
Recent amendments expanded monitoring and compliance requirements for affected facilities, including requirements associated with equipment leak detection, storage tanks, control devices, recordkeeping, and reporting. Operators should evaluate how these requirements affect existing monitoring programs and prepare for applicable compliance deadlines. Review current EPA rule information.
Trihydro helps gasoline distribution facilities evaluate Subpart 6B applicability and implement practical compliance programs tailored to their equipment and operations. Our team supports facilities from initial applicability determinations and compliance gap assessments through field monitoring, LDAR implementation, documentation, reporting, and ongoing compliance support.
Trihydro’s NESHAP Subpart 6B compliance services include:
- NESHAP Subpart 6B applicability determinations
- Compliance assessments and gap analyses
- OGI and Method 21 monitoring programs
- IFR tank LEL measurements
- Gasoline leak detection services
- LDAR program development and implementation
- Compliance reporting and documentation
- Regulatory strategy development
- Ongoing NESHAP compliance support

NSPS Subpart XXa (40 CFR Part 60, Subpart XXa) establishes standards of performance for affected facilities at bulk gasoline terminals that commenced construction, modification, or reconstruction after June 10, 2022. The regulation addresses VOC emissions from gasoline loading operations and equipment leaks, including requirements for vapor collection and control systems, pressure-vacuum vents, leak detection and repair (LDAR), monitoring, recordkeeping, and reporting.
Determining whether Subpart XXa applies requires evaluating a facility’s construction and modification history, affected equipment, and operational changes. Because modifications can trigger applicability, proposed facility changes and capital projects may warrant a regulatory review to determine whether additional Subpart XXa requirements apply.
Trihydro helps bulk gasoline terminal operators evaluate Subpart XXa applicability and implement practical compliance programs tailored to their equipment and operations. Our team supports facilities from applicability and modification evaluations through monitoring plan development, OGI and Method 21 leak detection, emissions monitoring, documentation, reporting, and ongoing compliance support.
Trihydro’s NSPS Subpart XXa compliance services include:
- Subpart XXa applicability and modification evaluations
- Monitoring plan development
- Appendix K OGI monitoring programs
- OGI and Method 21 leak detection services
- Vapor collection and control system compliance support
- LEL measurement services
- Emissions monitoring and reporting
- Compliance audits and assessments
- Compliance strategy and implementation planning

LeakTracker Pro® is Trihydro’s LDAR compliance management software designed to help facilities manage monitoring, leak detection, repair, recordkeeping, and reporting requirements in one system. The platform supports Appendix K, NESHAP Subpart 6B, NSPS Subpart XXa, and other federal and state compliance programs, helping operators manage overlapping requirements across facilities and equipment.
Effective compliance programs depend on accurate field data and timely follow-up. LeakTracker Pro® connects field data collection with regulatory workflows, monitoring schedules, repair deadlines, documentation, and reporting. Automated workflows and alerts help teams track upcoming inspections and unresolved leaks, while centralized records provide a consistent system for maintaining compliance documentation.
Trihydro combines LeakTracker Pro® with our air quality and LDAR expertise to help gasoline distribution facilities implement and manage practical compliance programs. The platform can be configured around applicable regulations, survey types, inspection frequencies, repair deadlines, user roles, and facility-specific workflows.
LeakTracker Pro® compliance management features include:
- Mobile OGI and LDAR field data collection
- Appendix K, NESHAP Subpart 6B, and NSPS Subpart XXa compliance management
- Monitoring and inspection scheduling
- Automated survey and repair deadline alerts
- Leak and repair tracking
- Photo and video documentation
- Equipment verification records
- Thermographer training and certification tracking
- Federal and state compliance reporting
- Excel and PDF data exports
- Role-based workflows and notifications
- Centralized compliance recordkeeping
Air Quality Compliance FAQs
Appendix K establishes a standardized methodology for optical gas imaging inspections using infrared cameras. It is not a standalone regulation; it applies when a referencing regulatory subpart incorporates Appendix K for affected equipment and inspections.
NESHAP Subpart 6B establishes HAP emission standards for area source gasoline distribution bulk terminals, bulk plants, and pipeline facilities. Applicability and specific obligations depend on the facility and affected equipment, so operators should document an applicability determination and evaluate the rule’s monitoring, testing, recordkeeping, and reporting provisions.
NSPS Subpart XXa establishes performance standards for affected facilities at bulk gasoline terminals that commenced construction, modification, or reconstruction after June 10, 2022. Modification determinations require review under the NSPS General Provisions, including 40 CFR §§ 60.2 and 60.14.
LDAR software can connect field data collection with inspection schedules, leak and repair tracking, deadlines, documentation, and reporting. A centralized system also helps facilities manage overlapping regulatory requirements, maintain consistent records, and identify unresolved compliance tasks.
Facilities should complete applicability and gap assessments, inventory affected equipment, update monitoring plans and procedures, confirm personnel and camera readiness, and establish reliable data-management workflows. Because EPA has proposed reconsideration of portions of the 2024 rule, operators should verify current final requirements and dates while continuing to prepare for requirements that remain in effect.
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Air Quality Compliance Projects
Trihydro delivers comprehensive air quality compliance solutions across the nation, helping clients navigate evolving environmental regulations and maintain compliance. From air permitting and emissions monitoring to leak detection and repair (LDAR), optical gas imaging (OGI), regulatory reporting, and compliance strategy, Trihydro combines technical expertise with practical, facility-specific solutions.
Contact me about your facility needs.

Jeremy Sell, PE,
Senior Vice President, Air and Process Services
Laramie, WY
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