Management of Produced Water from Coalbed Natural Gas Wells, Powder River Basin, Wyoming

John Kennedy, Kennedy Oil, 700 West 6th Street, Gillette, WY 82716, phone: (307) 682-3107, [email protected]

Management of produced water from coal bed natural gas (CBNG) wells in the Powder River Basin has become challenging because of increasing regulatory requirements by the state regulatory authority, the Wyoming Department of Environmental Quality (WDEQ). When CBNG was first being developed in the Powder River Basin, it was recognized that high-quality water produced from coal seams infiltrating into and recharging shallow aquifers would be considered beneficial to the environment and a reasonable disposal option. In response to the very stringent regulatory requirements of the WDEQ for direct discharge into drainages, more CBNG operators are moving toward containing water on-lease in infiltration impoundments. In response to this shift in method of water disposal, various groups that have opposed direct discharge of produced water are attempting to prevent storage in reservoirs and pits. The WDEQ has responded by imposing new requirements and conditions reportedly designed to protect shallow aquifers. However, it is not certain that these new regulations are based on sound scientific reasoning nor are there criteria for defining what is an aquifer.