This project consists of a study to test the feasibility of re-injecting and retrieving coal bed
methane (CBM) water into the Fort Union aquifer. This would involve a pilot well to evaluate the
subsurface geology to determine its ability to store CBM discharge water. If data indicates that
storage/retrieval is feasible, then the well would be completed as an observation well. A second
production/storage well and another observation well would then be completed.
Several CBM producers are currently injecting CBM water as a means of disposal of excess
produced water (DEQ currently has over 240 re-injection permits issued). Determining whether
storage of this water and later retrieval is cost effective is one purpose of the project.
Gillette had predicted a large increase in its population due to the recent CBM boom. Storage of
water in aquifers that are already experiencing drawdown would help Gillette in serving the needs
of their growing population.
To prevent contamination of the aquifer, prior to injection, CBM water would be disinfected with
a small disinfection facility built at the site. Water samples will be monitored for conductivity,
pH, chlorine and sulfates. Other assurances are needed as well to insure that wellfield treatment
chemicals are not introduced into the aquifer in toxic quantities.
RECOMMENDED LEGISLATIVE ACTION:
No legislative action required.