EPA, states requiring stricter methane leak detection testing, repairs
WASHINGTON D.C. – U.S. Environmental Protection Agency (EPA) final rules at reducing methane emissions from the oil and gas industry includes new requirements for finding and repairing leaks (fugitive emissions) at natural gas well sites, transmission compressor stations, processing plants, production gathering and boosting stations and at oil well sites.
In particular, owners/operators are required to implement a leak monitoring plan and utilize optical gas imaging (OGI) to conduct a biannual leaks survey. “Method 21,” an EPA method for determining VOC emissions from process equipment, may be used as an alternative to optical gas imaging.
The EPA requires the leak detection tests initially upon new installation and then semiannually. If, however, leaks are detected from more than 3% of components, the testing must be conducted on a quarterly basis.
The detected leaks must be repaired within 30 days, unless the repair requires shutting down production. In that case, operators are required to repair the leak at the next shutdown, or within two years. However, components with leakage rates greater than 500 ppm must be repaired within 15 days.
The final rule requires a 95% reduction of methane and VOC emissions from wet-seal centrifugal compressors (except for those located at well sites). Dry seal systems are not covered by the final rule. Additionally, the final rule requires owners and operators to replace rod packing systems in reciprocating compressors either on or before every 26,000 hr of operation, or every 36 months.
Several of the oil and gas producing states—Colorado, Pennsylvania and Ohio—are also implementing similar leak detection requirements. Most states of these states define repairable leaks based on a leakage rate of 10,000 ppm based on Method 21. Pennsylvania’s stricter rules insist on no detectable emissions or bubbles under Method 21.
Owners/operators are required to implement a leak monitoring plan and utilize optical gas imaging (OGI) to conduct a biannual leaks survey.