Evaporation-pond pilot suggested for Colorado salinity

Public scoping meetings are to be held by the US Bureau of Reclamation in December 2011 on the subject of the Paradox Valley Salinity Control Unit near Bedrock, Colorado.

The Dolores river, which passes through Paradox valley, used to pick up an estimated 250,000 t of salt annually in the valley. Since the mid-1990s, much of this salt has been collected by shallow wells and then injected into deep subsurface geologic formations.

The deep-well injection program has removed about 110,000 t of salt annually from the Dolores and Colorado rivers.

The existing deep-well injection facility may be approaching the end of its useful life and alternatives are being considered to continue the successful efforts to prevent salt from entering the river. One initial alternative is to collect brine from shallow wells along the Dolores River, evaporate the brine and encapsulate the produced salts in surface evaporation ponds.

The Colorado River Basin Salinity Control Forum, representing the seven basin states, has recommended that an evaporation pond pilot study be conducted in order to better evaluate potential future large-scale evaporation ponds as an alternative to deep-well injection.