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Fracking Contamination Traced to Leaky Well Linings

ByBridget MorawskiNOVA NextNOVA Next

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Even before videos of flaming tap water went viral, contaminated drinking water was a concern for many Americans living on or near fracking sites. Fracking involves injecting a solution of potentially toxic chemicals underground, which have the potential to seep into drinking water sources. Two new studies suggest it may not be the injections themselves that are contaminating water supplies, but leaks in poorly constructed wells that bring the gas to the surface.

On Monday, U.S. Department of Energy researchers in western Pennsylvania announced that they had “found no evidence that chemicals or brine water from the gas drilling process” had contaminated drinking water, according to a report by the Associated Press. The report further muddied the already hazy problem of determining the source of the drinking water contamination in these regions.

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Horizontal_Drilling_Rig
A horizontal drilling well used in fracking

But another study , published by the Proceedings of the National Academy of Sciences earlier this week, may have some answers as to why some people have been reporting contamination.

Matt McGrath, reporting for BBC News:

“The mechanism of contamination looks to be well integrity,” said one of the authors, Prof Robert Jackson from Stanford University.

“In about half the cases we believe the contamination came from poor cementing and in the other half it came from well casings that leaked.”

The current cement wall linings don’t appear to be strong enough to withstand the immense pressure used in fracking. Another part of the problem could be the speed at which these wells are drilled.

Here’s McGrath again, this time interviewing Quentin Fisher, a professor at the University of Leeds:

“The licensing system in the US means that companies have to drill a massive number of wells very quickly. This is not the case in the UK/EU so far more care can be taken to ensure that leakage into groundwater does not occur.”

Even if the weak wells are fixed, other studies have exposed issues related to fracking, including increased geologic activity .