Faulty gas wells are the main cause of drinking water contamination near homes in Pennsylvania and Texas shale formations, according to a new report.
The study, conducted by scientists from five universities, examined the gas content of over 130 drinking water wells in the two states.
{mosads}The scientists found that methane leaks from the natural gas drilling operations were more likely to come from the wells dues to a lack of cement surrounding its shaft, or “poor casing.”
At every cluster of drinking water wells examined, increased levels of natural gas from the Marcellus shale in Pennsylvania and Barnett shale in Texas were found, the report states.
“People’s water has been harmed by drilling,” said Robert B. Jackson, professor of environmental and earth sciences at Stanford and Duke. “In Texas, we even saw two homes go from clean to contaminated after our sampling began.”
The scientists note that the most of the issues identified as cause of contamination “can potentially be avoided by future improvements in well integrity.”
Another finding that may bode well for the industry is that hydraulic fracturing, or fracking, did not appear to be the cause of contamination.
“These results appear to rule out the possibility that methane has migrated up into drinking water aquifers because of horizontal drilling or hydraulic fracturing, as some people feared,” said Avner Vengosh, professor of geochemistry and water quality at Duke, who worked on the study.