Stories about unexplained illnesses have accompanied the nation’s gas drilling boom for years.
Residents living near gas drilling sites have reported skin rashes and gastrointestinal distress. Industry critics often blame hydraulic fracturing chemicals, even when the water had only minor “abnormalities.”
Now, researchers from the University of Texas at Arlington have found what could be a different culprit: bacteria.
"People were complaining of skin rashes and trouble breathing," said Dr. Kevin Schug, an analytical chemistry professor at UTA. "That made us think there might be something else at play here."
Two studies recently published in the peer-reviewed journal Science of the Total Environment discovered increased levels of bacteria — particularly dangerous ones that are difficult to kill — in contaminated water near gas drilling sites.
Schug, one of the authors and director of UTA's Collaborative Laboratories for Environmental Analysis and Remediation, or CLEAR, said the research doesn't conclusively connect fracking with the contaminated water. Naturally occurring natural gas, agriculture waste or some combination could be the contamination sources.
Despite criticism from anti-fracking activists, an Environmental Protection Agency study concluded that the industry hadn’t caused widespread water contamination. However, fracking and the waste it generates have been connected to scattered cases of water pollution.
Todd Staples, president of the Texas Oil & Gas Association, emphasized the EPA findings about water and drilling. He also said that drillers use multiple layers of steel and concrete to prevent contamination.
“Oil and gas companies are committed to protecting groundwater,” he said.
About the bacteria that researchers found, Staples said the connection to gas drilling is “based on proximity and nothing more."
The research, UTA's Schug said, does point to chemically-altered water sources as a friendly environment for some nasty organisms.
One of the study authors, Paula Stigler-Granados, assistant professor at the UTHealth School of Public Health in San Antonio, said these bacteria could cause gastrointestinal illnesses along with rashes and eye and ear infections.
The microbes are particularly worrisome for the very young, the elderly and those with compromised immune systems.
"There's a lot of views that groundwater is clean and that it doesn't need to be filtered,” she said. “There are people who have lived there all their lives thinking, 'I've drank this water forever and I'm fine.’ It might not be the same [water]."
Stigler-Granados said more work is needed to understand how groundwater environments are changing.
"The potential contribution of these microbes to these health effects is probably understudied, underappreciated, unknown," Schug said.
Staff and students at the CLEAR Lab have conducted extensive research about water quality in Texas, mostly focused on chemicals. It was only recently that they expanded the scope to include microorganisms.
Some bacteria are known to thrive in more hostile environments. In 2016, Ohio State University researchers found a new genus of bacteria — which they named Frackibacter — in an oil well and gas wells.
"As we've been involved more in conversations with oil and gas operators and even other industries looking to recycle waste water, you hear more and more concern about how microbes are interacting with those systems," Schug said.
For their latest studies, the UTA researchers tested private water wells in the Barnett Shale areas of North Texas and Eagle Ford Shale areas of South Texas. Researchers took water samples back to their lab and used lasers to identify the bacteria protein “fingerprints.” Schug said that’s a faster and cheaper approach than gene sequencing, which was used as a backup method.
Some of the bacteria found are known to develop drug resistance or are difficult to kill with chlorination. No specific illnesses could be attributed to the bacteria discovered during the research.
The Texas Department of State Health Services does not require reporting of infections caused by the bacteria in the UTA study, an agency spokesman said. So there is no data about patterns of those specific infections.
Schug said the study suggests there needs to be greater surveillance of private wells. Unlike public water supplies, there are no testing requirements for wells that serve relatively few people.
Another related UTA study found two different bacteria that are able to degrade chloroform and toluene; those chemicals respectively are cancer risks and could harm a person’s nervous system. Both of those bacteria were found in groundwater.
"It's an interesting possibility," Schug said. "You'd need to do a lot more work before you just throw those into somebody's water. ... We want to make sure they're safe."