Faulty Gas Wells Contaminated Drinking Water in Pennsylvania and Texas

A new scientific study concluded that poorly constructed wells are to blame for groups of methane-contaminated drinking water wells overlying the Marcellus and Barnett shale gas plays.

This adds to a growing body of research showing that oil and gas activities, including poorly constructed wells, pose a serious threat to the environment and human health. It also shows yet again that current practices and safeguards are not enough to protect communities across the country from the risks of unconventional oil and gas production.

The study examined samples from 133 drinking water wells near shale gas drilling sites in Pennsylvania and Texas. Using a diverse geochemical dataset, the researchers were able to not only detect contamination, but also determine the likely source of that contamination and the mechanism(s) that caused it.

Analysis revealed eight clusters of methane-contaminated drinking water, seven in Pennsylvania and one in Texas. The sources of the gas included the target gas-producing formations (the Marcellus and Barnett shales) and shallower gas-bearing zones. Poor well design, construction, and/or operation were identified as the mechanisms responsible for all eight contamination clusters. The samples in Texas actually documented increasing contamination over time.

Based on the geochemical data, the researchers concluded that it is unlikely that horizontal drilling or hydraulic fracturing created a conduit for gas to migrate from depth into drinking water in these specific cases. Some have wrongly interpreted this conclusion to mean that the study says that fracking doesn’t put drinking water at risk. However, that interpretation is about semantics, not science.

As Stanford professor Rob Jackson, co-author of the study, said, “I don't think homeowners care what step in the process the water contamination comes. They just care that their lives have changed because drilling has moved next door.”

The researchers go on to suggest that, “Future work should evaluate whether the large volumes of water and high pressures required for horizontal drilling and hydraulic fracturing influence well integrity.” In other words, the science is not yet clear on whether hydraulic fracturing could contribute to these types of well integrity issues that put drinking water at risk. Moreover, many scientific questions about the potential environmental and health impacts of fracking are unsettled.

Industry often claims to be using best practices, but studies like these call that into question. The alarm bell about the risks of poor well construction has been ringing for years; this study turned up the volume. It’s time for the oil and gas industry and our elected leaders to wake up.

While a handful of states have updated their well construction and other rules in the past several years, no state requires best practices across the board. Instead they too often rely on outdated, inadequate protections that have been in place for decades. States and the federal government need to modernize their oil and gas rules and enforce them strictly. Communities must have the right to protect themselves if the states or federal government won’t. And the oil and gas industry needs to step up and take responsibility for its messes and – more importantly – stop them from happening in the first place.