Based on a year-long analysis of core samples from four drinking water aquifers, "We found the potential for contamination is real, but there are ways to avoid or reduce the risk," says Robert B. Jackson, Nicholas Professor of Global Environmental Change and professor of biology at Duke.
"Geologic criteria that we identified in the study can help identify locations around the country that should be monitored or avoided," he says. "By no means would all sites be susceptible to problems of water quality."
Storing carbon dioxide deep below Earth's surface, a process known as geosequestration, is part of a suite of new carbon capture and storage (CCS) technologies being developed by governments and industries worldwide to reduce the amount of greenhouse gas emissions entering Earth's atmosphere.
The still-evolving technologies are designed to capture and compress CO2, emissions at their source - typically power plants and other industrial facilities - and transport the CO2 to locations where it can be injected far below the Earth's surface for long-term storage.
The U.S. Department of Energy, working with industry and academia, has begun the planning for at least seven regional CCS projects.
"The fear of drinking water contamination from CO2 leaks is one of several sticking points about CCS and has contributed to local opposition to it," says Jackson, who directs Duke's Center on Global Change.
"We examined the idea that if CO2 leaked out slowly from deep formations, where might it negatively impact freshwater aquifers near the surface, and why."