Here is a Reuters article about a government study that concludes fracking doesn’t necessarily hurt our water. The problem with such studies is always in the circumstances that were not considered. Keep in mind that the process involves punching a big hole through many different layers of strata, lining it with a big pipe and attempting to fill the gaps between pipe and strata with a cement-like substance. If successful, nothing leaks from the casing, and nothing can move up or down along the outside of the casing. The problem is that metal expands and contracts, the earth itself moves, and the pressures inside the pipe are extreme.

If you have ever had a wet basement, you know the problems inherent with holes in the ground and water. Once that hole has been punched it is there forever. Even if the well is properly sealed, the hole, the steel, the bentonite are all there to move and loosen and eventually leak. So be skeptical when you read reports like this:

Fracking not a ‘widespread risk’ to drinking water: U.S. EPA

Fracking for shale oil and gas has not led to widespread pollution of drinking water, a U.S. Environmental Protection Agency draft report said on Thursday, although it warned some drilling activities could potentially cause health risks.

The study does not consider the disposal of produced water.