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