For those who live in the vicinity of an oil and gas drilling well using hydraulic fracturing, the fear of water contamination is ever-present. Now a new study by Duke University has confirmed the belief that hydraulic fracturing (fracking) does cause dangerous leaks, but it explains that poorly sealed natural-gas wells—not the process itself—are likely to blame for dissolved gas leaking into private water wells.
Fracking is a drilling process that uses underground wells to inject chemically treated, pressurized fluids into underground shale deposits for the purpose of freeing trapped oil and gas for collection. In the latest study, published on June 24 in Proceedings of the National Academy of Sciences, researchers at Duke examined 141 water wells in Pennsylvania, all sitting on the Marcellus Shale, where fracking activity has exploded over the past few years. Of those wells included in the study, 82% had elevated levels of methane, which is the main component of natural gas. The findings confirm that residents’ drinking water is being contaminated by fracking activities taking place near their homes. While many of the wells were contaminated, those closest to drilling sites had the highest methane levels. Methane-contaminated water has been linked to health problems such as dizziness, blacking out, rashes, swelling of legs and elevated blood pressure.
While the study confirmed water contamination, it did not find that the process of using water and chemicals to crack shale formations was in itself responsible for contaminated fluids migrating into families’ drinking aquifers. Instead, the study found that drillers were at fault for the leaks because they were being negligent when drilling their wells; their failure to adequately seal the wells has allowed gas to flow upward, contaminating water resources used by families in their homes.
Rob Jackson, a professor of environmental sciences at Duke and lead author of the study, said, "Poor casing and cementing problems are the simplest explanation of what (caused the contamination that) we found."
Since the evidence largely confirms that methane in Pennsylvania wells is a result of fracking, the study should be used to force drillers to take more care when constructing their wells. The days of pretending that negligent activity does not affect public health should now come to an end. As Jackson says, "It's clear that we need to focus on well integrity from these results."