Spotlight: SWN Participates in Yale Groundwater Study

SWN has implemented a range of best practices – from well integrity procedures and greener hydraulic fracturing chemicals to rigorous produced water management and spill prevention practices – to ensure our operations do not impact groundwater. We also sample water wells surrounding our well pad locations, prior to drilling activities, to establish a baseline water characterization in the vicinity of our pad. The results of our water sampling program have assured us that our operations are not impacting drinking water wells. (See Our Record for detailed results.)

But we recognize that concerns still remain about the potential for methane to leak into groundwater. In 2014, we were approached by Yale University researchers who wanted to study the potential impacts of hydraulic fracturing on groundwater systems. We agreed to participate and allowed the researchers to drill eight shallow groundwater monitoring wells adjacent to our well sites in northeastern Pennsylvania (prior to any drilling or fracturing activities). These groundwater wells were then independently sampled and monitored before, during and after each phase of development. The researchers had complete independence in analyzing the data, reaching conclusions and publishing the results.

This was the first independent academic or industry study to test groundwater quality throughout unconventional drilling and hydraulic fracturing operations based on regular sampling from the same water monitoring wells close to natural gas wells.

Over two years, Yale researchers sampled 24 locations each month. They also recorded groundwater pressures before, during, and after we drilled, hydraulically fractured and placed seven wells into production.

The study, published in the Proceedings of the National Academy of Sciences in July 2018, found that while methane may be found in groundwater in the area, it is not coming from shale gas wells.

Instead, the researchers found that any methane detected in their test sites was naturally occurring methane in saline groundwater systems that can interact with local freshwater systems through natural cracks in deep rock. In addition, the study found that, particularly in mountain and valley topography, naturally occurring methane is more variable across time, location and concentration than previously recognized.

“We knew we were doing the right things to protect water resources,” notes Rowlan Greaves, Senior Staff Engineer at SWN. “But, we’re proud that our record of not impacting groundwater resources has been externally confirmed through this rigorous and highly reputable academic research.”