Hydraulic fracturing of shale formations, or fracking, to extract natural gas doesn't cause groundwater contamination, a new report has found.
However, while the fracking itself may not be responsible for such claimed effects as flammable drinking water and exploding houses, related processes are, including poor cement jobs and above-ground spills.
"These problems are not unique to hydraulic fracturing," points out Charles Groat, an Energy Institute associate director who led the project.
Hydraulic fracturing involves injecting a mixture of water, sand and chemicals at high pressure into a shale bed. This causes the rock to shatter, releasing natural gas.
The team examined reports of groundwater contamination in three prominent shale plays — the Barnett Shale in North Texas, the Marcellus Shale in Pennsylvania, New York and portions of Appalachia and the Haynesville Shale in western Louisiana and northeast Texas.
"Our goal was to provide policymakers a foundation for developing sensible regulations that ensure responsible shale gas development," says Groat. "What we've tried to do is separate fact from fiction."
The team found that natural gas found in water wells within some shale gas areas such as Marcellus can be traced to natural sources, and was probably present before fracking started.
Overall, they say, surface spills of fracturing fluids are a greater threat to groundwater sources than the fracking itself.
But, says Groat, much stronger guidelines are needed. There should be tighter surveillance of well construction and clear guidelines on responsibility in the event of a leak.