| The geological CO2 sequestration project at the Wyoming Rock Springs Uplift site is anticipated to result in the injection of 127.5 million tonnes (1.7 million tonnes per year) of CO2 per well into the Tensleep/Weber Sandstone and Madison Limestone formations over a 75 year period (Surdam et al., 2009). Large amounts of water must be extracted from the formations in order to maintain reservoir forces under fracture pressure limits. Sequestration of CO2 within the two aquifers would require approximately 75 million tonnes (1 million tonnes per year) of saline water to be removed from the reservoirs. An obvious challenge for this project is to determine how to manage the displaced water in order to prevent adverse environmental impacts. Therefore, the potential impacts of the displaced water on surface waters, soils, and vegetation ecosystems, where large amounts of displaced waters are utilized, were assessed in this study. Water treatment technologies were investigated to determine possible processes that might be implemented to reduce the salt content of the displaced water that would allow for other uses. Reverse osmosis (RO) and multi-stage flash (MSF) processes were considered the most promising desalination technologies, with RO more cost-efficient compared to MSF based on historical data. Consequently, it is imperative that possible scenarios be developed whereby the treated waters can be utilized for beneficial uses, which include: industrial---power plants or water treatment plants, oil and gas industry, and soda ash production; agricultural---irrigation and livestock; ecological---enhanced in-stream flow or fisheries, wetlands or artificial wetlands, injection for aquifer storage or recovery and recreation areas; domestic---drinking water, dust abasement, fire-fighting and vehicles wash; and others---mineral extraction. |
