Potential Impacts of Displaced Saline Waters On Soils and Vegetation: Geological Carbon Dioxide (CO2) Sequestration Project At the Rock Springs Uplift.

Sequestration of carbon dioxide (CO₂) within the Rock Springs Uplift, Wyoming, is expected to produce 9 million metric tons (7,300 acre-feet) of saline water per year, if 9 million metric tons of CO₂ are injected annually. Geological formations utilized for the CO₂ sequestration project must be dewatered in order to maintain fracture pressures at levels below required limits. The total dissolved solids (TDS) content of the formation waters that will be displaced during CO₂ injection has been reported to be higher than 20,000 mg/L, which, due to its high salinity, limits the use of the water. In addition, concentrations of some chemical constituents in the waters exceed EPA or State of Wyoming water quality standards. Therefore, the large amount of displaced waters has to be treated before land applying or considering its use for enhancing vegetation productivity. This presentation addresses the following key question: how would the soils and vegetation be affected by the saline displaced waters? The research area is located on east flank of the Rock Springs Uplift and is situated close to the Jim Bridger Power Plant. By using water data and different GIS layers of the soils and vegetation in the study region, an analysis was conducted to determine concerns and potential impacts related to the use of saline water on local ecosystems. Both the disposal of untreated water and beneficial uses of treated water have been assessed. Based on soils and vegetation types at the Rock Springs Uplift study site, potential opportunities for reusing and/or recycling treated waters, as well as an economical assessment, will be presented.