EPA Finalizes Rule to Eliminate Methane Leaks from Oil and Gas Sector

On November 30, 2023, the EPA released the proposed final text of a rule designed to limit methane emissions from oil and natural gas sources. This rulemaking stems from the EPA’s authority and obligation under Section 111 of the Clean Air Act to directly regulate categories of new stationary sources that cause or contribute to endangerment from air pollution, and to promulgate emissions guidelines for states to follow in regulating existing sources (designated facilities) in the source category.

This rule finalizes several proposed rulemaking actions designed to reduce air emissions of methane and volatile organic compounds (VOCs) from the Crude Oil and Natural Gas source category. EPA initially proposed a rule to limit methane emissions on November 15, 2021. That proposal was the subject of a supplemental notice of proposed rulemaking on December 6, 2022. Among other changes, the final rule sets emissions limits, and articulates a set of standards that target leaks and intentional flaring of methane, among other emissions sources. In addition, the rulemaking formally re-implements, with modifications, certain emissions categories that were removed in a 2020 rulemaking. The 2020 rulemaking was subject to a joint Congressional Review Act resolution that disapproved the final rule, and has not been in effect since the June 30, 2021 Congressional resolution.

This rule is important because methane is both the main component of natural gas and a potent greenhouse gas (GHG). Using one standard metric (the 100-year global warming potential (GWP), which is a measure of the climate impact of emissions of 1 ton of a GHG over 100 years relative to the impact of the emissions of 1 ton of CO2 over the same time frame), methane has about 30 times as much climate impact as CO2. Because methane has a shorter lifetime than CO2, it has a larger relative impact over shorter time frames, and a smaller one over longer time frames. In addition to climate benefits from methane emissions reductions, the EPA expects that volatile organic compound (VOC) emission reductions under the final rulemaking will improve air quality and improve health and welfare due to reduced exposure to ozone, particulate matter with a diameter of 2.5 micrometers or less (PM2.5), and hazardous air pollutants (HAP).

The EPA projects that, between 2024 and 2038, this rule will reduce methane emissions by approximately 58 million short tons. For the purposes of climate change, this reduction will have the equivalent effect of removing 1.5 billion tons of CO2 (using a GWP of 28 for methane). In addition, over the same period this rule is expected to reduce 16 million short tons of VOC and 590 thousand short tons of HAP from affected facilities.

This final rule will go into effect 60 days from the date that it is published in the Federal Register.