On August 30, 2024, the U.S. Environmental Protection Agency (EPA) published in the Federal Register the final approval of combustion engine rule revisions for reciprocating internal combustion engines (RICE), compression ignition (CI) internal combustion engines (ICE), and spark ignition (SI) ICE. The final revisions most notably incorporate changes to the manner in which certain records and reports are submitted to EPA, now requiring these records and reports to be submitted electronically through EPA’s Central Data Exchange using the Compliance and Emissions Data Reporting Interface (CEDRI). Furthermore, the finalized amendments include revisions to the frequency of oil changes for combustion engines. The revisions for combustion engines affected the following regulations:

• New Source Performance Standards (NSPS) Subpart IIII;
• NSPS Subpart JJJJ; and
• National Emission Standards for Hazardous Air Pollutants (NESHAP) Subpart ZZZZ.

Electronic Reporting Requirements

For combustion engines (i.e., RICE, CI ICE, and SI ICE) subject to NSPS Subparts IIII or JJJJ or NESHAP Subpart ZZZZ, the final amendments will require operators of stationary engines to submit electronic copies of certain records and reports through EPA’s Central Data Exchange using CEDRI or the Electronic Reporting Tool (ERT). The following records, notifications, and reports will now be submitted through EPA’s Central Data Exchange:

• Initial Notifications of Compliance via CEDRI;
• Performance Test Reports via ERT;
• Notification of Compliance Status (NOCS) via CEDRI; and
• Annual and Semiannual Compliance Reports via CEDRI.

By implementing the electronic reporting process, the finalized rule aimed to increase the usefulness of the data in these reports, improve data availability and transparency, and further assist in the protection of public health and the environment. EPA aimed to move away from paper-based reporting to minimize data reporting errors and increase reporting efficiency for operators required to submit electronic reports.

EPA has provided guidance on the electronic reporting process in CEDRI and the information with which operators of stationary engines will need to become familiar. The compliance date for the electronic reporting requirements is February 26, 2025. For annual and semiannual compliance reports, as electronic reporting is a new requirement, the compliance date is February 26, 2025, or one year from the date that the report template is available in CEDRI, whichever is later. For the revised electronic reporting requirements, CEDRI currently only has the annual reports available for emergency engines engaged in programs allowing up to 50 hours per year for minor sources to support local transmission.

Clarifications to the Oil Change and Inspection Requirement Frequency

Tables 2c and 2d of NESHAP Subpart ZZZZ includes requirements for oil changes and maintenance inspections for various types of CI and SI engines. Previously, the language in the requirements for such activities was phrased as:

“Change [Inspect]… every X,XXX hours of operation or annually, whichever comes first.”

The requirement caused ambiguity around the meaning of the term “annually” as this could be interpreted as “every calendar year”, and oil and filter changes and inspections could occur more than a year apart. To clarify this, EPA revised the language of the requirement to have oil changes and inspections occur as close as possible to 12 months to minimize emissions. The finalized amendments adjusted the language to be phrased as “within 1 year + 30 days of the previous change” instead of “annually” to provide clarification on the timeline for these maintenance and inspection requirements. EPA also clarified that oil filter changes should be on the same schedule as oil changes.

Clarifications to Table 4 of NSPS Subpart IIII

Table 4 to NSPS Subpart IIII includes emission standards for stationary fire pump engines, which has been a source of confusion as the table includes blank cells for the carbon monoxide (CO) emission standard in certain model years. The blank cells have caused uncertainty with the regulated community as these blank cells could be interpreted as indicating that there is no CO emission standard for certain model years. EPA revised Table 4 of NSPS Subpart IIII to remove the blank cells, which were replaced with the appropriate CO emission standard.

Non-Emergency Use Provisions

As part of the proposed rule published on June 26, 2023, EPA solicited information on the provisions pertaining to non-emergency operation of emergency engines. Under NSPS Subparts IIII and JJJJ as well as NESHAP Subpart ZZZZ, emergency engines are authorized to operate for up to 50 hours per year to mitigate local transmission and/or distribution limitations to avert potential voltage collapse or line overloads that could lead to the interruption of power supply in a local area or region, which are referred to as the “50-hour provisions”.

Through the proposed action, EPA did not propose any changes to the 50-hour provisions, but EPA wanted to engage stakeholders for evaluating the need of these provisions by assessing the circumstances and geographical locations for which these provisions are most prevalent. EPA sought considerations from stakeholders for whether to revise the provisions to narrow the applicability scope of these provisions or to propose removing these provisions from the Code of Federal Regulations (CFR).

EPA is considering the comments received regarding the remand of the 50-hour provisions; however, EPA did not respond to any of the comments in the final ruling or take any further action at the time. Therefore, the final rule does not include any revisions to these provisions, and the non-emergency use of 50 hours per year will be retained for the time being.

Potential Impacts and Considerations for Operators of Stationary Engines

The recently finalized revisions for regulations regarding stationary engines have a compliance date of February 26, 2025, for the electronic reporting process of notifications, records, and reports. Operators of stationary engines should become familiar with the EPA’s Central Data Exchange and the electronic reporting portals (i.e., CEDRI and ERT). The changes to the reporting format, in addition to language revisions for maintenance and inspection requirements, will impact operators of stationary engines. Trinity’s experience in air quality permitting and regulatory review allow for detailed insight on the potential impacts the rule revisions will have on stationary engines. Trinity experts are well-positioned to provide support for operators and/or facilities with stationary engines, which can include items such as:

• Registration for EPA’s Central Data Exchange, CEDRI, and ERT;
• Preparation of notifications and annual and semiannual compliance reports through CEDRI;
• Evaluation of test report submittals to confirm consistency with the extensible markup language (XML) schema for ERT;
• Compliance monitoring support for adhering to the revised language for oil and filter changes; and
• Review of air permits to ensure the rule revisions are incorporated correctly in the permit for your stationary engine.

If you would like to discuss these regulatory updates and the potential impacts on your facility, please contact one of our Engine experts, Lori Price and Jeremy Jewell, or your local Trinity Office.