Scientists have for the first time found dangerous levels of radioactivity and salinity at a shale gas waste disposal site that could contaminate drinking water. If the UK follows in the steps of the US “shale gas revolution”, it should impose regulations to stop such radioactive buildup, they said.
The Duke University study, published on Wednesday, examined the water discharged from Josephine Brine Treatment Facility into Blacklick Creek, which feeds into a water source for western Pennsylvania cities, including Pittsburgh. Scientists took samples upstream and downstream from the treatment facility over a two-year period, with the last sample taken in June this year.
Elevated levels of chloride and bromide, combined with strontium, radium, oxygen, and hydrogen isotopic compositions, are present in the Marcellus shale wastewaters, the study found.
Radioactive brine is naturally occurring in shale rock and contaminates wastewater during hydraulic fracturing – known as fracking. Sometimes that “flowback” water is re-injected into rock deep underground, a practice that can cause seismic disturbances, but often it is treated before being discharged into watercourses.
Radium levels in samples collected at the facility were 200 times greater than samples taken upstream. Such elevated levels of radioactivity are above regulated levels and would normally be seen at licensed radioactive disposal facilities, according to the scientists at Duke University’s Nicholas school of the environment in North Carolina.
Hundreds of disposal sites for wastewater could be similarly affected, said Professor Avner Vengosh, one of the authors of the study published in Environmental Science & Technology, a peer-reviewed journal.
“If people don’t live in those places, it’s not an immediate threat in terms of radioactivity,” said Vengosh. “However, there’s the danger of slow bio-accumulation of the radium. It will eventually end up in fish and that is a biological danger.”