USEPA issues supplemental proposal to reduce methane from oil and natural gas operations

22 November 2022

The USEPA's proposal is a significant step in fighting the climate crisis and protecting public health through sharply reducing methane and other harmful air pollutants from both new and existing sources in the oil and natural gas industry.


Eric Hodek

Eric Hodek

MBA, Principal
T: +1 303 382 5467
Thomas Samarco

Thomas Samarco

MS, Senior Managing Consultant
T: +1 724 720 9389
Natalie Ohlhausen

Natalie Ohlhausen

Senior Managing Consultant
T: +1 303 981 8058
M: +1 303 981 8058
Sonya Alcocer-Charles

Sonya Alcocer-Charles

Managing Consultant

On November 11, 2022, USEPA proposed an update to its November 2021 proposal rules under the New Source Performance Standards for Oil and Gas Sources as part of the Biden-Harris Administration Methane Action Plan.

The supplemental proposal aims to achieve more comprehensive emissions reductions from oil and natural gas facilities by improving standards and adding proposed requirements for sources not previously covered by the rules. The proposal also provides additional clarity to states that must develop plans to reduce methane emissions from existing sources, and for tribal nations that choose to develop their own plans.

USEPA is proposing to strengthen requirements from its November 2021 proposal including:

  • New Source Performance Standards (NSPS) under section 111(b) to reduce emissions of methane and smog-forming volatile organic compounds (VOCs) from new, modified and reconstructed sources
  • First nationwide emissions guidelines under section 111(d) for states that would be required to develop plans to limit methane emissions from existing sources

Oil and natural gas sources that were subject to previous NSPS would become subject to existing source standards under state plans. The table below shows which rule applies based on a source’s construction date:

Construction, reconstruction or modification date Which rule applies?  
After 8/23/11 and on or before 9/18/15 NSPS Subpart OOOO issued in 2012*
After 9/18/15 and on or before 11/15/21 NSPS Subpart OOOOa issued in 2016*
After 11/15/21 NSPS Subpart OOOOb will be finalized in 2023
*Existing sources built on or before November 15, 2021 will become subject to state plans under the emissions guidelines once they take effect.


The supplemental proposal will apply retroactively to any existing operating facility constructed on or before the rule promulgation date including those currently regulated under Subpart OOOO or OOOOa by requiring states to meet the emission guidelines established in this regulation in the development of State Implementation Plans.  

Summary of significant requirements for new, modified, reconstructed and existing sources (Subpart OOOOb/OOOOc)

Source type  Proposed requirement November 2021 proposal Implications
Fugitive emissions: well sites and centralized production facility1

Bimonthly or quarterly audible, visual, or olfactory (AVO) inspections

Quarterly optical gas imaging (OGI) surveys

Quarterly OGI for sites > 8 tpy of methane

Semiannual OGI for sites > 3 tpy of methane

The monitoring threshold proposed in November 2021 (> 3 TPY of methane) has been removed, and the supplemental proposal includes a new approach that would ensure every well site, regardless of size, is regularly inspected for leaks
Fugitive emissions: compressor stations1

Monthly AVO inspections

Quarterly OGI surveys

Compressor stations will now have to conduct monthly AVO inspections and increase the frequency of OGI surveys
Well closures

Submit a well closure plan

Conduct monitoring based on type of well site (i.e., single wellhead-only, small well sites)

Monitoring will need to be conducted based on type of well site, which could include AVO/OGI, until all wells are plugged, equipment removed, and no fugitive emissions are present
Fugitive emissions: super emitter response program2 (events > 220.5 pounds of met Root cause analysis and corrective action following notification of a super-emitter emissions event --
Root cause analysis would need to be submitted within 5 days of notification
Well liquids unloading3 Zero methane and VOC emissions / best management practices Zero methane emissions / best management practices

The rule is not specific to the technology/best management practices, and the burden is on the operator to demonstrate that zero emission technology is not feasible

Supplemental proposal also includes reporting requirements

Reciprocating compressors Rod packing replacement No changes  Rod packing will be replaced based on monitored leak rate (2 scfm) as opposed to at scheduled intervals
Pneumatic pumps at natural gas plants, well sites, compressor stations, and centralized production facility Zero emissions (methane and VOC) pumps that are not powered by natural gas4 Only included natural gas plant This is more stringent than current requirements to control by 95%
Pneumatic controllers at natural gas plants, well sites, compressor stations, and centralized production facility Zero emissions (methane and VOC) controllers5 Zero emissions (methane) controllers This is more stringent than current requirements to control by 95%
Flares and combustion control devices

Demonstrate 95% control efficiency through a performance test or manufacturer’s performance test

Continuous pilot flame or CPMS

Monthly Method 22

Net heating value of gas sent to flare or combustor

Flow of gas sent to flare or combustor


Uncertified flares or combustion control devices will require a performance test for any affected facility

Additional monitoring requirements being proposed to ensure flares and enclosed combustion devices operate properly

Associated gas from oil wells Route to sales or beneficial uses / control device No changes  Associated gas must be recovered for sale or beneficial uses and can only be routed to flare (95% control) if recovery is technically infeasible
Storage tanks  -- No changes  --
1Supplemental proposal provides a pathway to use a broader range of innovative and continuous technologies in lieu of OGI
or Method 21.
2Supplemental proposal created the Super Emitter Response Program, which includes large emissions events often caused by malfunctions or abnormal operating conditions (i.e., unlit flares and open thief hatches on storage tanks).
3Supplemental proposal no longer considers all liquids unloading at existing wells to be a modification. 
4Sites that do not have access to electricity would be allowed to use natural gas driven pneumatic pumps, but would have to demonstrate that it’s not technically feasible. Emissions from these pneumatic pumps would either have to be routed to a process on site or controlled.
5Supplemental proposal includes two types of pneumatic controllers previously not included: controllers where emissions are routed to a sales line, used for onsite fuel or another useful propose, and self-contained controllers. These controllers, if properly maintained, could be used to meet the zero emissions standard.


Submitting comments

USEPA is soliciting comments on the entire supplemental proposal. Comments will be accepted for 60 days after the proposal is published in the Federal Register. USEPA will also hold a virtual public hearing beginning 21 days after publication.



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