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EPA Extends NSPS OOOOb/c Compliance Deadlines: What Operators Need to Know

EPA Extends NSPS OOOOb/c Compliance Deadlines: What Operators Need to Know

Introduction

On July 28, 2025, the U.S. Environmental Protection Agency (EPA) issued an interim final rule extending multiple compliance deadlines in the 2024 New Source Performance Standards (NSPS OOOOb) and Emission Guidelines (EG OOOOc) for the oil and natural gas sector. These changes aim to give operators and state agencies more time to meet methane and VOC control requirements. The extensions cover a wide range of equipment, operational and monitoring requirements for storage vessels, flare and enclosed combustion emission control systems, valve leak repairs, process controllers, implementation of the Super Emitter program and state EG OOOOc plan submission to the EPA.

Key Deadline Extensions

The interim final rule extends the compliance date by 18 months for all of the following emission source requirements, except for the Net Heating Value monitoring requirements, which are extended by 120 days.

Storage Vessels – Production Throughput Determination

  • Extended the compliance date for the requirement to use a “30-day production period” for determining rule applicability (e.g., 6 tons/yr VOC and 20 tons/yr CH4 for a tank battery).
  • With the extension, operators can use other, non-specified periods to determine production rate used to calculate emissions to determine applicability.
  • New Deadline: January 22, 2027.

Storage Vessels – Legally and Practically Enforceable (LPE) Limits

  • Extended the compliance date for the option to obtain Legally and Practically Enforceable (LPE) limits in the state air permit to qualify a tank battery as not being an affected source under OOOOb. Note: Many States (except Texas) have not designed their permits for LPE limits.
  • If a tank battery has LPE limits indicating less than 6 tons/year (tpy) of VOC and less than 20 tpy CH4, the tank battery can be exempt from OOOOb requirements.
  • With the extension, a facility may be exempt from OOOOb storage tank requirements without obtaining an LPE if it uses a state air permit to limit the tank battery’s potential to emit VOC emissions to less than 6 tpy and methane emissions to less than 20 tpy.
  • No changes to emission control requirements.
  • New Deadline: January 22, 2027.

Flares and Enclosed Combustion Devices (ECDs)

  • Extended the compliance date for the following requirements related to flares and ECDs:
    • Operating a continuous pilot or combustion flame for flares and ECDs.
    • Operating a system to send alarms to nearest control room when a pilot flame is unlit.
    • Initial performance testing for ECDs that are not tested by the manufacturer prior to installation. This extension is for the field testing of ECDs.
  • No change to requirement that all ECDS be tested every 60 months after previous performance test including manufacturer tested and field tested devices.
  • New Deadline: January 22, 2027, for each of these requirements.

Monitoring Net Heating Value (NHV) of Gas to Flares and ECDs

  • Extended the compliance date for monitoring net heating value (NHV) of gas sent to flares and ECD using continuous monitors, NHV grab samples, exhaust TOC monitoring, or alternative test methods (e.g., ALT-156).
  • New Deadline: November 28, 2025.

Equipment Leak Repairs

  • Extended deadline for the requirement to repair leaking valves by installing low-emission (low-E) valve packing, replacing the valve with a low-E valve, or performing a drill-and-tap repair with low-E injectable packing, unless these actions are determined to be infeasible.
  • New Deadline: January 22, 2027.

Covers/Closed-Vent Systems for Tanks

  • This pertains to covers/closed-vent systems for controls for tanks, compressors, controllers, pumps and requirement to demonstrate operating system with no identifiable emissions (NIE). 
  • Extended compliance date for the requirement to conduct periodic or continuous monitoring to demonstrate that the system operates with no identifiable emissions (NIE). Approved monitoring methods include AVO, OGI, Method 21, and advanced technologies for both periodic and continuous monitoring.
  • New Deadline: January 22, 2027.

Process Controllers

  • Extended deadline for requirement to use zero-bleed designs for process controllers. For existing and new controllers, use low bleed controllers (<=6 scf/hr bleed rate – same as standard for Alaska with no electricity) until extended deadline date.
  • New Deadline: January 22, 2027.

Super Emitter Program

  • Extended deadline for USEPA to implement the Super Emitter program. The Super Emitter program will be used for remote detection and reporting of CH4 leaks greater than or equal to 100 kg/hr.
  • New Deadline: January 22, 2027.

State Plan Submission for Emission Guideline (EG) OOOOc for Existing Sources

  • Extended deadline for state environmental agencies to submit CH4 Emissions Guidelines (EG) reduction plans for existing crude oil and natural gas sources.
  • EG OOOOc will apply to existing sources that commenced construction, modification, or reconstruction on or before December 6, 2022.
  • There is no change to the compliance date for all existing sources subject to EG OOOOc under state and federal rules. The compliance date remains March 2029.

Summary

The EPA’s July 28, 2025 interim final rule provides operators and state agencies additional time to meet the methane and VOC control requirements under NSPS OOOOb and EG OOOOc. Most affected requirements now have an extended compliance date of January 22, 2027, with the notable exception of the Net Heating Value monitoring requirements, which are extended only to November 28, 2025.


The extensions cover multiple equipment and operational categories, including:

  • Storage vessels (production throughput determination and LPE limits)
  • Flares and enclosed combustion devices (operation, alarm systems, and field performance testing)
  • Equipment leak repairs (low-emission valve packing or replacement)
  • Covers/closed-vent systems (NIE demonstration via AVO, OGI, Method 21, or advanced technologies)
  • Process controllers (transition to zero-bleed designs)
  • Super Emitter program implementation
  • State plan submission deadlines under EG OOOOc

While state plan submission dates are extended, the final compliance deadline for existing sources under EG OOOOc remains March 2029.

Conclusions

This interim final rule signals EPA’s recognition of the time and resource demands faced by both operators and state agencies in implementing the 2024 methane and VOC rules. By providing an 18-month extension for most compliance requirements, EPA is allowing more flexibility for planning, procurement, installation, and testing of control equipment, as well as for integrating advanced monitoring technologies.

Operators can consider:

  • Re-evaluate compliance schedules considering the new deadlines.
  • Engage with state permitting authorities to ensure LPE limit pathways are available where beneficial.
  • Plan for early NHV monitoring compliance due to its shorter extension window.
  • Maintain focus on the unchanged March 2029 deadline for EG OOOOc compliance at existing sources.

By acting now to align compliance strategies with the revised timelines, operators can reduce implementation risks and ensure smooth adherence to both federal and state methane reduction requirements.

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