Frequently Asked Questions: Implementing Emissions Guidelines (OOOOc)

View frequently asked questions about EPA's 2024 final rule for oil and natural gas operations - implementing emissions guidelines

On this page:

How will EPA ensure meaningful engagement during the development of State Plans?
If states are allowed to apply less stringent standards, how can it be guaranteed that emissions will be reduced to the level estimated in the final rule?
Can states just add methane to their existing state rules in order to comply with the oil and gas final rule emission guidelines?
Are natural gas underground storage facilities covered by the EG OOOOc?
What are some ways to incorporate existing state rules into a proposed State Plan?
What needs to be included in my State or Tribal Plan?
Who determines what qualifies as a designated facility?

How will EPA ensure meaningful engagement during the development of State Plans?

State and Tribal plans must include 10 items as shown in 40 CFR § 60.5363c. Included in these 10 items are two items that verify:

Documentation of meaningful engagement on such plan or plan revisions as specified in 40 CFR § 60.23a(i)
Certification that the required hearing on the State or Tribal plan was held, a list of witnesses and their organizational affiliations, if any, appearing at the hearing, and a brief written summary of each presentation or written submission as specified in §60.23a(c) through (e)

If states are allowed to apply less stringent standards, how can it be guaranteed that emissions will be reduced to the level estimated in the final rule?

EG OOOOc at § 60.5365c allows states to apply a standard of performance to a designated facility that is less stringent than otherwise required by the emission guidelines, provided that the state meets the requirements specified in the General Provisions at § 60.24a. More information on the General Provisions can be found at 40 CFR Part 60 Subpart Ba.

Can states just add methane to their existing state rules in order to comply with the oil and gas final rule emission guidelines?

For a state to leverage existing state rules for the purpose of State Plan submittal, a state should consult the criteria in §60.5364c, “How do I apply to use my state standards as part of my state or Tribal plan submission?”. Among other required criteria, the designated pollutant in the state rule must be the same as that identified in EG OOOOc. The designated pollutant in EG OOOOc is greenhouse gases in the form of a limitation on emissions of methane. See §60.5361c,“Which pollutants are regulated by this subpart?”.

Some state programs regulate VOC, for example, but those programs cannot be leveraged to fulfill the requirements of EG OOOOc unless amended to regulate GHGs in the form of limitations on methane.

In addition to ensuring the criteria in §60.5364c are met, a state would also need to meet all other requirements of EG OOOOc to ensure the State Plan includes each component necessary for the plan to be approvable. A state must also follow the submittal requirements in EG OOOOc. Please refer to the final preamble 89 FR 16996 to 17002 for more discussion of leveraging existing state rules for purposes of State Plan submission.

Are natural gas underground storage facilities covered by the EG OOOOc?

EG OOOOc aims to assist states in developing, submitting, and implementing plans to establish performance standards to limit methane from various existing sources (i.e., designated facilities) in the Crude Oil and Natural Gas Source Category. If a state does not submit an approvable state plan, EPA is required to implement a Federal Plan.

§ 60.5430c “What definitions apply to this subpart?”, defines the Crude oil and natural gas source category as: “(1) Crude oil production, which includes the well and extends to the point of custody transfer to the crude oil transmission pipeline or any other forms of transportation; and (2) Natural gas production, processing, transmission, and storage, which include the well and extend to, but do not include, the local distribution company custody transfer station.”

Designated facilities in EG OOOOc such as well sites, storage vessels, fugitive emission components, centrifugal and reciprocating compressors, pumps, process controllers, etc. that are located at a site that has underground natural gas storage, and that is in the defined Crude Oil and Natural Gas Source Category, will become subject to a plan implementing EG OOOOc.

Further, per the definitions included in OOOOc at § 60.5430c “What definitions apply to this subpart?”, underground storage vessel “means a storage vessel stored below ground”. A storage vessel, is defined at §60.5430c as: “Storage vessel means a tank or other vessel that contains an accumulation of crude oil, condensate, intermediate hydrocarbon liquids, or produced water, and that is constructed primarily of nonearthen materials (such as wood, concrete, steel, fiberglass, or plastic) which provide structural support. A well completion vessel that receives recovered liquids from a well after startup of production following flowback for a period which exceeds 60 days is considered a storage vessel under this subpart. A tank or other vessel shall not be considered a storage vessel if it has been removed from service in accordance with the requirements (see § 60.5396c(c)(1)) until such time as such tank or other vessel has been returned to service. For the purposes of this subpart, the following are not considered storage vessels:

Vessels that are skid-mounted or permanently attached to something that is mobile (such as trucks, railcars, barges or ships), and are intended to be located at a site for less than 180 consecutive days. If you do not keep or are not able to produce records, as required by § 60.5420c(c)(4)(iv), showing that the vessel has been located at a site for less than 180 consecutive days, the vessel described herein is considered to be a storage vessel from the date the original vessel was first located at the site. This exclusion does not apply to a well completion vessel as described above.
Process vessels such as surge control vessels, bottoms receivers or knockout vessels.
Pressure vessels designed to operate in excess of 204.9 kilopascals and without emissions to the atmosphere.”

A well completion vessel that receives recovered liquids from a well after startup of production following flowback for a period which exceeds 60 days is considered a storage vessel under this subpart. Specifically, at § 60.5430c reads: “Well completion vessel means a vessel that contains flowback during a well completion operation following hydraulic fracturing or refracturing. A well completion vessel may be a lined earthen pit, a tank or other vessel that is skid-mounted or portable. A well completion vessel that receives recovered liquids from a well after startup of production following flowback for a period which exceeds 60 days is considered a storage vessel under this subpart.”

What are some ways to incorporate existing state rules into a proposed State Plan?

Per §60.5364c, states and eligible Tribes can apply to use their state/Tribes' standards as part of their state/Tribal plan submission. In order to apply for this, states must meet the criteria specified below (a) and provide supporting documentation that the state has met those criteria specified below (b), among meeting other requirements in EG OOOOc:

1. You must demonstrate that the state standards of performance established for a designated facility in your state or Tribal plan meet the equivalency criteria specified below when compared to the designated facility presumptive standards specified in EG OOOOc:
  1. Designated facility
  2. Designated pollutant
  3. Standard type/format of standard
  4. Emission reductions (considering applicability thresholds and exemptions)
  5. Compliance determination method
  6. Ongoing compliance assurance requirements (monitoring, recordkeeping and reporting requirements)
2. You must provide the supporting documentation that you met the equivalency criteria specified in (a) and in the following:
  1. Your state plan should identify the designated facility requirements of your state program that you are submitting for approval to become federally enforceable requirements under the plan
  2. You must include a detailed explanation and analysis of how the relied upon state standards are at least as stringent as the requirements of the final EG
  3. You must include a copy of the actual state law/regulation or document submitted for approval and incorporation into the state plan

Please refer to the final preamble 89 FR 16996 to 17002 for more discussion of leveraging existing state rules for purposes of State Plan submission.

What needs to be included in my State or Tribal Plan?

Per §60.5363c, a State or Tribal Plan must include:

Compliance schedules for each designated facility or logical grouping of designated facilities
Standards of performance for designated facilities that are at least as stringent as the emission guidelines. Standards for performance for designated facilities must apply at all times, including periods of startup, shutdown, and malfunction
Performance testing, monitoring, recordkeeping, and reporting requirements
Documentation of meaningful engagement on such plan or plan revisions
Certification that the required hearing on the state or Tribal plan was held, a list of witnesses and their organizational affiliations, if any, appearing at the hearing, and a brief written summary of each presentation or written submission
Provision for state progress reports to EPA
Identification of enforceable state mechanisms that you selected for implementing the emission guidelines
Demonstration of your state’s legal authority to carry out the Clean Air Act section 111(d) state or tribal plan

See also the completeness criteria in 40 CFR 60.27a(g).

Who determines what qualifies as a designated facility?

As stated in the preamble of the final rule, Standards of Performance for New, Reconstructed, and Modified Sources and Emissions Guidelines for Existing Sources: Oil and Natural Gas Sector Climate Review (89 FR 16848):

“Once the EPA establishes NSPS in a particular source category, the EPA is required in certain circumstances to issue EG to reduce emissions from existing sources in that same source category. Specifically, CAA section 111(d) requires that the EPA prescribe regulations to establish procedures under which states submit plans to establish, implement, and enforce standards of performance for existing sources for certain air pollutants to which a Federal NSPS would apply if such existing source were a new source. The EPA addresses this CAA requirement both through its promulgation of general implementing regulations for CAA section 111(d) as well as through specific EG … In accordance with CAA section 111(d), states are required to submit plans pursuant to these regulations to establish standards of performance for existing sources for any air pollutant: (1) the emission of which is subject to a Federal NSPS; and (2) which is neither a pollutant regulated under CAA section 108(a) (i.e., criteria pollutants such as ground-level ozone and particulate matter (PM), and their precursors, like VOC) [footnote omitted] nor a HAP regulated under CAA section 112. See also definition of ‘‘designated pollutant’’ in 40 CFR 60.21a(a). The EPA’s general implementing regulations use the term ‘‘designated facility’’ to identify those existing sources that may be subject to regulation under the provision of CAA section 111(d). See 40 CFR 60.21a(b).”

Back to FAQ list

Frequently Asked Questions: Implementing Emissions Guidelines (OOOOc)

Controlling Air Pollution from the Oil and Natural Gas Operations