Scientists have found elevated levels of cancer-causing chemicals in the drinking water in North Texas’ Barnett Shale region — where a fracking boom has sprouted more than 20,000 oil and gas wells.
Researchers from the University of Texas, Arlington tested water samples from public and private wells collected over the past three years and found elevated levels of heavy metals, such as arsenic. Their findings, released Wednesday, showed elevated levels of 19 different chemicals including the so-called BTEX (benzene, toluene, ethyl benzene and xylenes) compounds.
Heavy metals are toxic when ingested, and BTEX compounds are considered carcinogenic when ingested. Exposure to BTEX compounds is also associated with effects on the respiratory and central nervous system. The study found elevated levels of toxic methanol and ethanol, as well.
The researchers were clear that they had not determined the source of the metals and chemicals. However, they noted that “many of the compounds we detected are known to be associated with [fracking] techniques,” and said the data support further research on the potential of fracking contamination.
In hydraulic fracturing, or fracking, oil and gas deposits in underground shale are extracted by forcing a mix of water and chemicals at high pressure into the earth.
According to the study, published in Environmental Science & Technology, chemical leaks can occur when well casings fail. Some estimates show this happens in approximately 3 percent of new gas well operations, but the researchers point out that recent data indicate well casing failure rates closer to 12 percent within the first year of well operation.
The risk of water contamination from fracking remains largely unknown. Dr. Kevin Schug, who led the UT study, told ThinkProgress that research funding remains a major hurdle.
“It’s challenging, but it’s necessary. The only way to really know the story is to keep doing these thing and keep doing them over time,” he said.
To date, this is “the most comprehensive groundwater study in connection to this whole process,” Schug said.
The study comes on the heels of a broad Environmental Protection Agency (EPA) report, which concluded that fracking has not led to “widespread, systemic” water contamination. While the report was touted by oil and gas interests as saying fracking is safe, it did find several specific instances of contamination from fracking and concluded that fracking creates several key vulnerabilities that could potentially undermine the health of drinking water in the United States.
Some environmentalists criticized the report, saying the EPA’s data was incomplete. “The EPA found disturbing evidence of fracking polluting our water despite not looking very hard. This study was hobbled by the oil industry’s refusal to provide key data,” Kassie Siegel, senior counsel for the Center for Biological Diversity, said in an emailed statement to ThinkProgress.
The results of an investigation into the causes of two chemical spills in Arlington, Texas, also came out this week. The investigators found that the spills, which prompted the evacuation of nearly 100 homes near a Vantage Energy fracking site, were caused by the company’s faulty equipment. The results also revealed that the 911 call, made as chemical-laced water rushed down Arlington’s streets, originated from Vantage’s headquarters in Pennsylvania.
Oil and gas is big business in Texas, which passed a law this year that prevents towns and cities from banning fracking. Denton, which is located in the Barnett Shale region, was forced to revoke its ban — the first in Texas — this week, citing the cost of litigation.
This post has been updated with comments from Dr. Kevin Schug.