A recent Yale study debunked fears about contamination of Pennsylvania’s water resources by hydraulic fracking. The three-year-long study revealed that hydraulic fracturing is not the cause of contaminated drinking water in the Marcellus Shale. Instead, the study traced the contamination to above-surface activities.

Published in the Proceedings of the National Academy of Science, Yale researchers analyzed 64 samples of groundwater gathered from private residences located in northeastern Pennsylvania. This research covered about 2,800 square miles of the Marcellus Shale. Researchers discovered that the groundwater-contamination samples were most likely affected by the gas-extraction operations above the ground surface, not migration from subsurface, hydraulic-fracking activities. The level of chemicals found in the groundwater samples were within state and federal limits, only detectable by advanced and highly sophisticated research instruments.

“And really, even using that word contamination is a stretch[,] because when these detections were made, they were still at very low concentrations,” stated Yale assistant professor, Desiree Plata.

This study directly refutes the stance taken by opponents against hydraulic fracking. One long-time opponent, the Sierra Club, continues to advocate against hydraulic fracking, claiming that “[f]racking has contaminated the drinking water of hundreds of thousands of Americans,” despite a growing number of conflicting studies. For example, the Environmental Protection Agency (EPA) released a study earlier this year finding “that [fracking techniques] have not led to widespread, systemic impacts on drinking water resources in the United States.”

The Yale study builds on EPA’s research, revealing more encouraging information about hydraulic fracking. These studies come after another supportive study published in Environmental Science & Technology Letters by Duke University, explaining that hydraulic fracking accounts for merely “a fraction of total industrial water use,” less than one percent of water used nationwide. Together, these studies suggest that the hydraulic-fracking process is far less intensive on water resources than its opponents may claim.