California regulators on Thursday adopted tougher standards for natural gas utility delivery systems to tighten up prevention programs for identifying and plugging methane leaks.
As a companion to a rule adopted in March by the California Air Resources Board for reducing oil and natural gas well emissions, the California Public Utilities Commission (CPUC) established a rule requiring plans be developed by utilities to reduce by 2030 current emission levels by 40%.
Under SB 171, enacted in 2014, California regulators were required to implement gas leak management programs. The CPUC now requires the state's major gas utilities to implement 26 different best practices that include:
Retaining leak data and publishing leak maps by zip code;
Enhancing mobile leak detection technologies;
Using stationary methane detection equipment at compressor stations, terminals, storage facilities, citygates, and meter/regulator stations;
Surveying underground facilities every three years and above-ground equipment annually;
Repairing leaks as quickly as possible, and never longer than three years; and
Mitigating emissions from blowdowns during tests/repairs.
Representatives of the Environmental Defense Fund (EDF) called the latest rules the nation's most comprehensive. Tim O'Connor, director of EDF's California oil and gas programs, said the action is "another example of how states are stepping up even as the federal government pulls back on important environmental protections."
According to EDF, data indicate that California utilities in 2015 emitted 6.6 Bcf of methane collectively, volumes more than what was estimated to have been dispersed by the entire Aliso Canyon storage well leak, which lasted four months.
"Utilities are required by law to fix gas leaks that pose a threat to public safety, but until now, there were no mandates requiring them to address leaks that cause climate pollution," an EDF spokesperson said.