On June 10, 2022, the Environmental Protection Agency (EPA) proposed to amend the 1994 National Emission Standards for Hazardous Air Pollutants (NESHAP) for Gasoline Distribution Terminals major source category (Subpart R) and the area source category (Subpart BBBBBB, or 6B). As part of this announcement, EPA also proposed amendments to the 1988 New Source Performance Standards (NSPS) for Bulk Gasoline Terminals (Subpart XX) via a new subpart, Subpart XXa. The proposed amendments apply to nearly 9,500 gasoline distribution facilities. The changes will affect storage tanks, loading operation controls, equipment leak detection, performance testing, and compliance reporting requirements.

Why is EPA proposing updated NESHAP and NSPS regulations?

Under the Clean Air Act (CAA), EPA is required to periodically assess and revise air toxics standards to help keep regulatory requirements in-line with evolving industry practices and technology improvements. This review process is generally referred to as a risk and technology review (RTR). EPA’s latest RTR of NESHAP and NSPS evaluated current practices in emission reduction to assess whether current practices achieve greater emission reductions than existing requirements for facilities in the Gasoline Distribution source category related to storage tanks, loading operations, and equipment leaks.

EPA’s RTR identified several changes in the approach to emissions reduction, resulting in proposed amendments. The proposed amendments include:

• Establish volatile organic compound (VOC) emission limits (new Subpart XXa) for applicable bulk gasoline terminal facilities that commence construction, reconstruction, or modification after June 10, 2022
• Set lower loading rack emission limits
• Strengthen cargo tank vapor-tightness requirements
• Require additional storage tanks controls
• Require instrument monitoring (i.e., Method 21 or optical gas imaging [OGI]) to detect equipment leaks
• Revise monitoring and operating requirements for control devices
• Require electronic submission of compliance reports and performance test reports through EPA’s CEDRI system
• Remove startup, shutdown, and malfunction exemption and add general duty language for facilities

For the proposed changes with the NESHAP regulations, EPA is generally proposing that compliance will be required three years after final rule publication.

What are the estimated benefits of the proposed regulatory amendments?

EPA estimates the proposed amendments will reduce emissions of hazardous air pollutants from the Gasoline Distribution source category by 2,220 tons per year (tpy) and will reduce emissions of volatile organic compounds by 45,400 tpy.

Tell me more about each Subpart amendment.

We have summarized EPA’s proposals below. However, the proposed rules include many additional details that will be critical to meeting the compliance requirements, if finalized. We have included direct links to the proposed rule language included in the EPA docket for this rulemaking to simplify your review process.

NESHAP Subpart R Major Sources

EPA’s proposed redline changes for NESHAP Subpart R can be found here. In summary, proposed changes include:

• Change the vapor recovery unit (VRU) compliance standard from 10 milligrams of total organic carbon (TOC) per liter of gasoline loaded (mg/L) to 5,500 parts per million (ppm) TOC (as propane) on a 3-hour rolling average.
• For vapor combustion units (VCU), EPA proposes that the temperature operating limit be established by capturing combustion zone temperature on a 5-minute block (excluding periods of no gasoline loading), hourly average combustion zone temperatures be determined based on the 5-minute blocks, and 3-hour rolling average temperatures be determined from the hourly average data. During the 6-hour performance test, the lowest of the 4 recorded 3-hour averages will establish the temperature limit established during the performance test. Compliance will be based on capturing data following the same approach. In addition, EPA proposes that performance tests will now be required at least every 5 years with the initial “new” test required within 3 years of final rule promulgation.
• Facilities using flares (redefined in the proposed rule; flares combust with a flame versus a combustion chamber) will generally need to meet Refinery MACT CC flare requirements within 3 years of final rule promulgation.
• Require fitting controls for external floating roof tanks consistent with NSPS Subpart Kb. Upgrades must be made during the first tank degassing 3 years after the final rule, but not more than 10 years after the final rule.
• Require lower explosive limit (LEL) monitoring as part of the annual visual inspection requirement for internal floating roof tanks. Although the first required monitoring event is 3 years after final rule, note that EPA expects that facilities may have to upgrade riveted roofs to meet the LEL standard and expects facilities will use the 3-year period to make necessary upgrades. An LEL reading above 25 percent on a 5-minute rolling average constitutes an inspection failure.
• Eliminate the Applicability Equations currently used as a major source applicability screening tool.

NESHAP Subpart BBBBBB (6B) Area Sources

EPA’s proposed redline changes for NESHAP 6B can be found here. In summary, proposed changes include:

• Lower emission limits for loading racks at large bulk gasoline terminals to 35 mg TOC/L gasoline loaded. EPA also requests comment on further reducing this limit to 10 mg/L. No change is proposed to the current 80 mg/L limit for small area source terminals.
• Change the vapor recovery unit (VRU) compliance standard from 80 milligrams TOC mg TOC /L gasoline loaded to 19,200 parts per million (ppm) TOC (as propane) on a 3-hour rolling average (which EPA views as equivalent to 35 mg/L).
• For VCUs, EPA proposes facilities either meet the temperature limit (as described above in Subpart R) or meet Refinery MACT Subpart CC flare requirements (by installing a calorimeter and supplementing natural gas if the vent stream BTU content falls below MACT CC requirements).
• Require vapor balancing for loading storage vessels and gasoline cargo tanks at bulk gasoline plants with maximum design capacity throughput of 4,000 gallons per day or more.
• Require fitting controls for external floating roof tanks consistent with NSPS Subpart Kb.
• Require LEL monitoring as part of the annual visual inspection requirement for internal floating roof tanks. Although the first required monitoring event is 3 years after final rule, EPA expects facilities may have to upgrade riveted roofs to meet the LEL standard and expects facilities will use the 3-year period to make necessary upgrades. An LEL reading above 25 percent on a 5-minute rolling average constitutes an inspection failure.

NSPS Subpart XXa New, Modified, or Reconstructed Sources (after June 10, 2022)

EPA’s proposed language for the new NSPS Subpart XXa can be found here. In summary, proposed changes include:

• Expand the affected loading operation to include rail car loading.
• Facilities commencing construction after June 10, 2022, must meet a 1 mg/L TOC limit or, if a VRU, 550 ppm TOC measured as propane on a 3-hour rolling average.
• Facilities commencing reconstruction or modification after June 10, 2022, must meet a 10 mg/L TOC limit (versus the current 35 mg/L limit) or, if a VRU, 5,500 ppm TOC measured as propane on a 3-hour rolling average.
• Facilities using a flare must generally meet Refinery MACT Subpart CC flare BTU measurement requirements.

Cargo tank vapor tightness testing

• Require a graduated cargo tank vapor tightness certification from 0.5 to 1.25 inches of water pressure drop over a 5-minute period, depending on gasoline compartment size. This requirement will apply consistently for NESHAP Subparts R and 6B, and NSPS Subpart XXa. These new testing requirements will be required to be in place 3 years after final rule promulgation.
  

Equipment leak monitoring

• Require semiannual instrument monitoring of the vapor collection system (e.g. Method 21 [10,000 ppm as propane leak limit] or optical gas imaging [OGI]) for major source gasoline distribution facilities at NESHAP Subpart R facilities, annual monitoring at NESHAP 6B facilities, and quarterly monitoring at NSPS XXa facilities. Repair requirements apply for all leaks detected, including if detected by AVO outside of instrument monitoring events. EPA also proposes that OGI monitoring pursuant to NSPS XXa must follow the recently proposed Appendix K requirements (Appendix K will not apply to the NESHAP facilities since Appendix K is specific to NSPS).

Want to provide feedback? Submit comments by August 9^th.

EPA is accepting comments through August 9, 2022. Be sure to identify any submitted comments by Docket ID No. EPA–HQ– OAR–2020–0371. See the Federal Register publication for details on how to submit comments. 

Questions for us?

Trihydro has assisted facilities with regulatory compliance since 1984. Our regulatory specialists are available to help facilities in the gasoline distribution source category understand how the proposed regulatory updates impact existing projects and operations. We also have dedicated software (LeakTracker Pro^TM) designed to support oil and gas facilities with their environmental compliance needs. Contact us if we can be of assistance!