Effluent Guidelines

Coalbed Methane Extraction Industry

Discharges from coalbed methane (CBM) extraction from onshore oil and gas facilities are not subject to effluent limitations guidelines or standards under the Oil and Gas Extraction Category, 40 CFR Part 435. EPA did not consider such discharges in developing the requirements in Part 435.

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What is Coalbed Methane Extraction?

Coalbeds are a source of unconventional gas. CBM is naturally created during the geologic process of converting plant material to coal (coalification). To extract the methane, CBM operators drill wells into coal seams and pump out ground water (produced water or CBM wastewater). Removing the ground water from the formation is necessary to produce CBM, as the water removal reduces the pressure and allows the methane to release from the coal to produce flowing natural gas.

How are Technology based Requirements Determined?

National Pollutant Discharge Elimination System (NPDES) permits for coalbed methane discharges are currently developed according to the best professional judgement (BPJ) of the permit authority, based on the factors specified in 40 CFR 125.3(c)(2). The BPJ-based requirements that have been applied to the management of coalbed methane wastewater vary significantly from state to state, ranging from limitations on some conventional pollutants prior to discharge, to prohibition of direct discharges to waters of the U.S. (For more information on the BPJ permit process, see Chapter 5 of the NPDES Permit Writers' Manual).

Rulemaking Activities

In 2010, EPA published a report based on its detailed study of the coalbed methane extraction industry. Based on that report, EPA initiated a rulemaking to develop controls for pollutant discharges from the CBM industry. Following initiation of the CBM rulemaking, EPA collected and analyzed more data. EPA concludes that while effective technologies exist, are demonstrated, and may be affordable for some sites, these technologies are not economically achievable for the CBM extraction industry as a whole. Therefore, the Agency is not developing national effluent limitations guidelines for these operations. Dischargers must still comply with NPDES requirements and must have a NPDES permit before wastewater can be discharged.

Additional Resources

Additional Information

To obtain more information on coalbed methane extraction, please contact Ahmar Siddiqui, (siddiqui.ahmar@epa.gov) at 202-566-1044.

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