What are the current management practices for disposal of CBNG produced water?
Currently, CBNG produced water in the Powder River Basin is primarily managed by the following methods: Untreated Discharge – Discharge to streams is allowed so long as a NPDES permit has been issued. Any discharge must comply with the applicable surface water standards. • Treated Discharge – Currently several methods of water treatment are being used or proposed in the Powder River Basin. These include ion exchange, zeolite treatment, and reverse osmosis among others. There is presently one ion exchange CBNG treatment facility operating in Montana. Impounded – This method involves constructing a pond in which CBNG produced water is stored. Depending on the design of the impoundment, water may infiltrate to the subsurface and/or evaporate. In some cases, enhanced evaporation processes are used. There are several terms for these impoundments: “holding ponds”, “zero discharge ponds” or “infiltration ponds”. Land applied to crop or rangeland – through some form of irrigation equipment. Ma
