Oakland, Calif. – The recent discovery of high levels of benzene in wastewater from oil and gas fracking operations in California turns out to be just the tip of the iceberg. An extensive review of a year-old state data by the Environmental Working Group has found that wastewater from hundreds of fracking operations was heavily contaminated with a toxic stew of chemicals known to cause cancer, reproductive harm and nervous system damage.
The findings are especially disturbing in light of revelations in recent months that oil and gas wastewater was being illegally injected into protected drinking water aquifers in California’s Central Valley. Some of these disposal wells have been shut down by the state.
EWG details its findings in a report titled Toxic Stew: What’s in Fracking Wastewater?, being released on the same day that state lawmakers are scheduled to hold an oversight hearing to examine the threats to groundwater from oil and gas drilling waste.
“We have long suspected that California’s fracking wastewater was full of harmful chemicals, and the first publicly available data not only confirms our suspicions but reveals just how toxic this wastewater is,” said EWG Senior Scientist Tasha Stoiber, co-author of the report. “Our findings should be a wake-up call for other states where drilling operations may be inadequately regulated.”
In addition to the known carcinogen benzene, tests of wastewater samples found chromium-6, lead and arsenic – all listed under California’s Proposition 65 as causes of cancer or reproductive harm – in 35-to-50 percent of the samples. The wastewater also carried, on average, thousands of times more radioactive radium than the state’s public health goals, as well as elevated levels of potentially harmful ions nitrate and chloride ions.
Because California is the only state to require comprehensive chemical testing of fracking wastewater and public disclosure of the results, the analysis also provides a unique window on what chemicals likely contaminate such wastes nationwide.
Hydraulic fracturing, or fracking, involves injecting large amounts of water mixed with sand and chemicals under high-pressure into underground formations in order to create a network of cracks and release trapped gas or oil. The contaminated water must then be disposed of in some manner.
In September 2013, California passed a landmark law that requires drilling companies to test their fracking wastewater and publicly disclose the results. EWG analyzed the reported data from the first full year of the program’s operation, which revealed startling levels of petroleum chemicals, heavy metals and radioactive elements, along with high levels of dissolved solids.
Although the data provides a unprecedented revelations about the chemicals in fracking wastewater, EWG’s report concludes that California’s reporting system is plagued by major flaws. Many drilling companies failed to report full details of the chemicals their testing found, and records for some wells are missing altogether.
“As we reviewed California’s fracking wastewater data, it became clear that the first year of this reporting system is not fulfilling its promise of providing full and transparent information,” said Renee Sharp, EWG’s director of research. “There was too little oversight by the state and not enough communication with drilling companies, which led to massive gaps with missing or incomplete information.”
EWG is calling on the state to put an immediate stop to the disposal of oil and gas drilling wastewater into wells that may put California’s water supplies at risk, even if that means halting oil and gas drilling in these locations. Once drinking water becomes contaminated it is extremely costly, in some cases impossible, to clean up, EWG said.
The report makes several recommendations to ensure the protection of water sources, including calling for testing at every location where illegal injection of wastewater has occurred. Reporting requirements should be streamlined and strengthened to provide complete and transparent information about the chemicals in fracking wastewater as well as details of how the wastes are disposed of.