Before-and-After Comparison Puts Fracking to the Test

by Eric Ellman

Advance arrangement with homeowners and industry has allowed Clifton R. Musser Professor of Hydrology Jim Saiers to launch the first ever study of groundwater quality impacts before, during, and after hydraulic fracturing of a new natural gas well in the Marcellus shale of Pennsylvania’s Susquehanna County. 

By siting monitoring wells directly above where fracturing is planned, and drawing water from the same aquifer that overlies the fractured zone and which serves residents, Saiers expects to produce a robust data set that will discriminate between natural and manmade impacts on drinking water supplies and help answer persistent questions around the controversial technology.

Such a simple before-and-after testing strategy has never been done in conjunction with shale-gas exploration. The study – seeded with a $100,000 grant from the Yale Climate and Energy Institute and more than matched by another $570,000 raised, in part, through assistance of the YCEI Advisory Board – could be easily and inexpensively replicated in shale gas plays around the country, Saiers says, wherever resource potential and drinking water concerns conflict.

America has an uneasy relationship with the boom in natural gas that slakes its energy thirst.  The nation enjoys record low prices of the resource, but is strongly divided over the technology that makes those prices possible.  A 2012 survey by the Yale Project for Climate Change Communication and the George Mason University Center for Climate Change Communication determined that people who had developed opinions on “fracking” were almost equally split on the topic, and equally strong in their beliefs.  Ever since the 2010 movie “Gasland” elevated awareness of fracking nationwide, water quality impacts and fugitive methane have been two of the most compelling issues for its opponents. 

To help resolve those questions in the Marcellus, Erica Barth-Naftilan, a PhD candidate working under Saiers, has installed a network of multi-level sampling wells near the locations of fourteen gas-well pads to assess the consequences of fracking horizontally drilled gas wells over one mile below.  The wells being monitored run beneath the properties of dozens of landowners, several of whom have granted permission to install groundwater monitoring wells on their properties or to collect water samples from their private wells.  

Previous studies of groundwater impacts involving hydraulic fracturing have also relied on homeowner cooperation. States like Pennsylvania require drillers to obtain water quality samples from all homes within a ½ mile radius of a new well. But a comprehensive understanding of how hydraulic fracturing impacts the surrounding environment requires more data than can be gathered from private wells fortuitously located in a zone of interest.  Ideally it involves repeated sampling over the depth of the aquifers to see the potential impacts of fracking in space and time.

“Others may have suggested doing something like this,” says Saiers, “but no one’s ever gotten the necessary cooperation.”

Over the course of three months, homeowners agreed to participate in a study whose results they hoped would confirm that their water supplies were safe from contamination by fracking they had allowed beneath their property.  But it was coordination with the oil and gas exploration company that was most critical. 

“The only way this project could happen was with the drilling company providing knowledge of where and when they would drill for gas,” says Barth-Naftilan. “We work with them,” Barth-Naftilan emphasizes, “but we operate autonomously.”  Yale researchers directed where the groundwater monitoring wells would be installed, sample when they please, and own and control the data.  “There are no restrictions on the types of data we collect nor on the publication of our findings,” says Saiers.

“People will view the results through the lens of their own agendas, but this is a scientific study,” he says.  “We’re collecting baseline data now, and we will continue to gather data as fracking begins this summer.  We’ll draw conclusions based on that evidence.  People are free to question our conclusions.  Ultimately, over the long run, conclusions that are borne out by the evidence will last.”