The oil and gas industry faces some of the most stringent regulations from the Environmental Protection Agency (EPA). Requirements for emissions monitoring, reporting, and reduction are among the most prominent examples. 40 CFR Part 60 Subpart OOOO (Quad O) and Subpart W of the Greenhouse Gas Reporting Program (GHGRP) establish specific criteria that oil and gas companies must meet to maintain compliance. This guide will help you understand your obligations and how you can meet them with the right air emissions management software.
Failing to comply with these regulations puts your organization at serious risk. As of 2025, EPA fines under the Clean Air Act can exceed $59,000 per day per violation. Criminal charges are also a potential outcome, especially in cases of knowingly falsified records.
Finalized in 2012, Subpart OOOO of 40 CFR Part 60 lays out New Source Performance Standards (NSPS) for oil and gas facilities that began construction, modification, or reconstruction after August 23, 2011. It regulates VOC emissions from various types of equipment, including compressors, pneumatic controllers, and storage vessels, as well as leaks at gas processing plants.
Under this rule, operators must reduce VOC emissions by at least 95% using approved methods such as vapor recovery units or flares. The rule laid out requirements for initial performance testing along with periodic compliance checks, leak monitoring, and recordkeeping. Facilities are required to submit reports demonstrating their compliance with emissions control requirements.
In 2016, the EPA expanded requirements with Subpart OOOOa, which came into effect for facilities constructed, modified, or reconstructed after September 18, 2015. This introduced methane-specific emissions standards for oil and gas facilities, expanding the scope beyond VOCs and being the first industry NSPS to focus specifically on methane emissions.
Quad Oa also established fugitive emissions reporting requirements for well sites and compressor stations. Operators were required to develop and implement leak detection and repair (LDAR) programs, conduct regular monitoring, and submit semi-annual reports to demonstrate compliance.
In 2023, the EPA finalized another addition to the rule, Subpart OOOOb, coming into effect for oil and gas facilities constructed, modified, or reconstructed after December 6, 2022. This section introduced significant methane emissions control requirements.
Quad Ob established the Methane Super Emitter Program, which targets large methane releases of 100 kg/hr or more. Certified third parties use remote sensing technologies to detect and report these events to the EPA. Upon notification from the EPA, operators must investigate these events within 5 days and submit a mitigation report within 15 days.
The rule also expanded the options that facilities have for methane detection. Technologies such as continuous monitoring systems and aerial surveys are now allowed as alternatives to traditional leak detection methods, with other potential options permissible upon EPA approval.
The EPA finalized Subpart OOOOc in March 2024, establishing additional guidelines for oil and gas facilities constructed, modified, or reconstructed on or before December 6, 2022. Unlike other additions to Quad O, this section specifically targets existing sources rather than new sources.
Quad Oc requires states to develop and submit implementation plans by March 9, 2026, detailing how they will enforce methane emissions reductions on existing facilities. Oil and gas facilities will have up to three years to achieve compliance with these state plans after EPA approval. The EPA is authorized to implement a federal plan for states that fail to submit acceptable plans.
The guidelines outlined in Quad Oc focus on reducing methane emissions from various sources, including pneumatic controllers and pumps, storage vessels, compressors, and fugitive emissions.
Subpart W of 40 CFR Part 98 establishes specific greenhouse gas reporting requirements for petroleum and natural gas facilities emitting 25,000 metric tons or more of CO2 equivalents. Organizations must submit annual reports to the EPA by March 31 each year if they fall into any of these industry segments:
• Onshore petroleum and natural gas production
• Offshore petroleum and natural gas production
• Onshore natural gas processing
• Onshore natural gas transmission compression
• Onshore petroleum and natural gas gathering and boosting
• Onshore natural gas transmission pipelines
• Underground natural gas storage
• Liquefied natural gas (LNG) storage
• LNG import and export equipment
• Natural gas distribution
Each industry segment has specific sources and types of equipment that it must report. Operators must calculate emissions through EPA-approved methods, including direct measurement, engineering estimates, or emissions factors.
Oil and gas operators must maintain detailed supporting data, such as operating hours and throughput. Facilities are required to conduct data validation checks and maintain records for at least three years. Reports are submitted through the EPA’s e-GGRT system, like other reports under the Greenhouse Gas Reporting Program (GHGRP).
In May 2024, the EPA finalized amendments to Subpart W to increase methane emissions reporting requirements. This change introduced new calculation methodologies to improve accuracy. It also introduced previously unreported emission sources such as nitrogen removal units, produced water tanks, mud degassing, and crankcase venting. The addition also specifies the inclusion of any large release events identified through the Methane Super Emitter Program.
The wide range of sources covered and extensive detail required under both Quad O and Subpart W can make managing emissions data a considerable challenge for oil and gas facilities. The most effective way to centralize data, automate calculations, and adapt to changing requirements is to utilize air emissions management software specifically designed to address these challenges.
Having the right tools lets you meet regulatory requirements along with working toward your emissions reduction targets. Beyond compliance, reducing methane emissions improves ESG performance and meets investor expectations for climate transparency, especially under frameworks like TCFD and CDP.
Providing the data the EPA expects in your reports requires bringing together data from a wide range of sources, applying the appropriate factors and calculations, and delivering the results in the right format. Trying to tackle this using your own spreadsheets and calculations opens the door to potentially costly errors while also consuming more and more of your team’s valuable time.
Instead, you can turn to ERA’s Air Emissions Management Software to streamline every aspect of compliance. Bulk data uploads and automation ensure that emissions data from all of your sources and equipment is always accurate, validatable, and easy to manage. Built-in emissions factors and calculations meet the EPA requirements, drawing from AP-42 and API standards.
Automated report generation lets you quickly prepare a wide range of federal and state reports with your emissions data. Beyond NSPS and the GHGRP, you can rely on the same dependable data management and calculations to streamline your TRI, Tier II, NEI, and other mandatory reporting.
Many emissions sources reported under Subpart W also contribute to TRI, Tier II, and NEI submissions. Centralizing data capture ensures consistency and saves significant time across all compliance programs.
ERA’s regulatory database is maintained by a team of seasoned experts, ensuring that your team always has access to the most up-to-date requirements. Our solutions evolve alongside the regulatory landscape, allowing your team to focus on their core responsibilities instead of scrambling to keep up with new EPA rules.
Quad O and Subpart W are two key examples of the ongoing emissions compliance challenges that oil and gas facilities must face. Recent updates indicate that requirements are only becoming stricter, and there is every reason to believe that this trend will continue into the future. Looking ahead, the EPA is expected to target smaller sources and expand methane monitoring requirements further. Proactive data systems can help future-proof your operations against these upcoming mandates.
If you’re concerned about whether your oil and gas facilities are fully compliant or are looking for a way to save time and money on your emissions reporting, then ERA has the tools you need. Schedule a discovery call with one of our project analysts today to see how we can solve your organization’s compliance challenges.
Contributing Scientists of This Article: