EPA Releases Final Methane Rule for New and Modified Oil and Gas Wells

A new methane rule is an essential part of President Obama's climate initiative. Finalized on May 12, it is designed to cut methane emissions from the oil and natural gas sector, and is considerably stronger than the one proposed last summer.

"The agency also said it is kicking off work on a rule for methane leaks at existing wells, but acknowledged that won’t come until after Obama has left office," writes Devin Henry, energy and environment reporter at The Hill.

Methane (CH4) is second most prevalent greenhouse gas emission, after carbon dioxide. "Methane's lifetime in the atmosphere is much shorter than carbon dioxide (CO2), but CH4 is more efficient at trapping radiation than CO2," according to the Environmental Protection Administration. "Pound for pound, the comparative impact of CH4 on climate change is more than 25 times greater than CO2 over a 100-year period."

The new rule removed "exceptions for low-producing wells, expanding leak monitoring and requiring quicker repairs for leaks," explains Henry. "If fully implemented, it will reduce 520,000 short tons of methane in 2025, or the equivalent of 11 million metric tons of carbon dioxide. The EPA’s proposed rule would have cut up to 400,000 short tons of methane."

The rule will apply to the source of one third of the anthropogenic (man-made) methane emissions in the United States. Enteric fermentation, resulting from the digestive systems of domestic livestock, are second at 22 percent, though globally it is 28 percent. Landfills are next at 20 percent, followed by coal mines at 9 percent, and manure management at 8 percent (thus agriculture would account for 30 percent).

Pie Chart from EPA's Overview of Greenhouse Gases:  [Anthrogenic] methane emissions 

U.S. Methane Emissions, By Source

Note: All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014.

It's important to bear in mind that natural sources, such as decomposition occurring in wetlands, account for almost 40 percent of total global CH4 emissions.

The new rule will enable President Obama to meet an agreement he made with Canadian Prime Minister Justin Trudeau in March.

"Earthjustice, which represents green causes in legal cases, said it “will defend this rule in court when the oil and gas industry tries to weaken it," adds Henry.

Air pollution as well as greenhouse gas emission reduction

"The standards also are expected to reduce 210,000 short tons of ozone-forming , volatile organic compounds (VOCs) in 2025, along with 3,900 tons of air toxics, such as benzene, toluene, ethylbenzene and xylene," states EPA's press release.

To access the final rule and fact sheets, including an overview and summaries of specific requirements for different segments of the oil and gas industries, click here.

Hat tip to Alan Drake, via Sierra Club energy forum.