uic program

        There are eight major oil fields on the reservation that use injection of groundwater for enhanced oil recovery.  It is believed that there are about 200 active wells injecting groundwater from oil field operations, and also a large number of abandoned wells.  Injection wells are rugulated by the EPA in accordance with federal Underground Injection Control (UIC) regulations adopted pursuant to the SDWA.  In addition to the injection systems, some groundwater from oil operations is separated from the oil and discharged into surface waters.  These operations are required by the CWA to obtain NPDES permitsm from the EPA for their discharges.  In other cases, wastes may be placed in lined pits for evaporation.

        The UIC program involves a complex interaction among BIA, the EPA, the BLM, and the Tribes.  The EPA administers the UIC regulations and sometimes receives assistance from the BLM with field inspections.  The BIA issues and administers oil leases as a part of its trust responsibility to the Tribes.  The BLM manages the actual field operations after the BIA has isued a lease.  BLM makes determinations regarding the  operations of the wells underground, while the BIA generally manages both the leases and surface activities.  Records are kept by the three federal agencies and by the Wyoming Oil and Gas Commission.  Our GIS staff are currently mapping out all UIC injection wells.   This will allow for analysis of the interaction of oil field operations with water supply and water quality on the reservation, creating the potential for greater Tribal input into lease management decisions.