Using a new method of analysis, a team of researchers from five U.S. universities has determined that oil and gas activity, specifically faulty well integrity, led to the contamination of several water wells in the southern Parker County area.
Scientists have tied poor casing and cementing of oil and gas production wells to methane found in well water in Parker County, as well as seven areas in Pennsylvania, contradicting statements from state regulators and the industry, who claim their research shows oil and gas industry activity has not caused the issue.
“People’s water has been harmed by drilling,” Robert Jackson, professor of environmental and earth sciences at Stanford and Duke, said in a press release Monday. “In Texas, we even saw two homes go from clean to contaminated after our sampling began.”
One of the researchers, Dr. Avner Vengosh, professor of geochemistry and water quality at Duke, told the Democrat that scientists’ analysis indicated that the methane contamination in the Texas wells is likely the result of gas traveling into the groundwater aquifer by way of a nearby oil or gas well.
The Duke, Ohio State, Stanford, Dartmouth and University of Rochester scientists published their peer-reviewed study Monday in the Proceedings of the National Academy of Sciences.
Researchers used data from samples obtained from 20 Texas wells between December 2012 and November 2013, as well as data obtained from 113 wells in the Marcellus Shale area in Pennsylvania and New York.
“Sampling sites included wells where contamination had been debated previously; wells known to have naturally high level of methane and salts, which tend to co-occur in areas overlying shale gas deposits; and wells located both within and beyond a one-kilometer distance from drill sites,” according to researchers.
“We found eight clusters of wells — seven in Pennsylvania and one in Texas — with contamination, including increased levels of natural gas from the Marcellus Shale in Pennsylvania and from shallower, intermediate layers in both states,” said Thomas H. Darrah, assistant professor of earth science at Ohio State, who led the study while he was a research scientist at Duke.