Dialogue | What are the risks of extracting natural gas by means of hydraulic fracturing (“fracking”)?
Ninety percent of new natural gas wells utilize fracking, in which high-pressure water and sand are used to free up gas trapped in impermeable rock (such as shale and coal beds) deep underground. These operations can have a significant negative impact on local water systems.
For example, fracking just one well typically requires 2 million to 4 million gallons of water, as well as a variety of chemicals—some of them toxic—to reduce friction, prevent corrosion, and kill bacteria in the well.
Though most shale gas deposits are far deeper than freshwater aquifers, reducing the potential for groundwater contamination from fracking chemicals, there have been incidents of aboveground chemical spills and gas leaks into well water, which can make people sick and increase the risk of fires and explosions.
Once a well has been tapped, the fracking chemicals are pumped out along with any naturally occurring water. This “flow-back” water is often temporarily stored in open-air pits that, while lined, can leak or overflow during heavy rains. Because of its large volume, high salinity, and the presence of fracking chemicals, flow-back water is difficult to process in municipal wastewater treatment plants.
We therefore need strong policies to support renewable energy and energy efficiency, which can reduce natural gas demand, and regulations to minimize the environmental damage caused by fracking and other methods of fuel extraction. To learn more, visit the UCS website at www.ucsusa.org/naturalgas.
Also in this issue of Earthwise:
Whose Cars Are Greenest