More than 20 gas transmission pipeline operators pledged to reduce methane emissions from pipeline and storage infrastructure and to do more to share information on methane releases and reduction efforts.

The companies — including major operators Kinder Morgan Inc., TransCanada Corp., Williams Cos. Inc., Enbridge Inc., Cheniere Energy Inc., Dominion Energy Inc. and Consolidated Edison Transmission LLC — committed to installing low-emissions pneumatic controllers, minimizing emissions during maintenance and repair work, upgrading certain emissions-prone aspects of transmission and storage compressors, doing more leak surveys, and reporting methane emissions.

"[T]hese principles are about continuously improving existing practices and finding new and innovative ways to minimize methane emissions from interstate natural gas transmission and storage operations in a prudent and environmentally responsible manner," Donald Santa, the Interstate Natural Gas Association of America's, or INGAA's, president and CEO, said in an Aug. 13 statement. "Our members commit to doing this while both maintaining pipeline integrity and safe operations and minimizing adverse impacts to customers and communities."

INGAA, whose members operate about 200,000 miles of pipeline, highlighted in an Aug. 13 white paper the emissions reduction potential for compressor stations, venting and leaks on the sector's equipment. INGAA said member companies would survey their transmission and storage compressor stations by 2022. The companies did not set a specific emissions reduction target volume.

Natural gas transmission and storage infrastructure emitted about 20% of the U.S. gas industry's methane released in 2016, according to U.S. Environmental Protection Agency estimates. The 2016 total was a 44% decrease from 1990 methane emissions for the transmission and storage segment, according to the EPA's greenhouse gas inventory.

Multiple studies have found that a large percentage of emissions come from a relatively small percentage of equipment. For instance, research from 2015 indicated that the highest-emitting 10% of sites contributed 50% of the aggregate methane emissions on transmission and storage infrastructure. INGAA pointed to a Pipeline Research Council International report that indicated that addressing issues with less than 3% of certain kinds of leaking components could curb emissions from compressor station leaks by 60%.

Methane is a potent greenhouse gas with a higher global warming potential value than carbon dioxide. Shareholder activism has already driven some oil and gas companies to be more transparent about methane emissions, and the EPA and the American Petroleum Institute have both launched voluntary programs geared toward curbing methane releases from the oil and gas industry.