Elevated levels of radioactivity, salts and metals have been found in river water and sediments at a site where treated water from oil and gas operations is discharged into a western Pennsylvania creek.
“Radium levels were about 200 times greater in sediment samples collected where the Josephine Brine Treatment Facility discharges its treated wastewater into Blacklick Creek than in sediment samples collected just upstream of the plant,” said Avner Vengosh, professor of geochemistry and water quality at Duke University’s Nicholas School of the Environment.
The new Duke study examined the quality of shale gas wastewater from hydraulic fracturing and the stream water above and below the disposal site. The study found that some of the discharged effluent is derived from the Marcellus shale gas flowback water, which is naturally high in salinity and radioactivity.
High concentrations of some salts and metals were also observed in the stream water. “The treatment removes a substantial portion of the radioactivity, but it does not remove many of the other salts, including bromide,” Vengosh said.
“When the high-bromide effluents are discharged to the stream, it increases the concentrations of bromide above the original background levels. This is significant because bromide increases the risks for formation of highly toxic disinfection by-products in drinking water treatment facilities downstream.”
“The radioactivity levels we found in sediments near the outflow are above management regulations in the U.S. and would only be accepted at a licensed radioactive disposal facility,” said Robert B. Jackson, professor of environmental science at Duke. “The facility is quite effective in removing metals such as barium from the water but concentrates sulfates, chlorides and bromides. In fact this single facility contributes four-fifths of the total downstream chloride flow at this point.”
The Duke team also analyzed sediments for radium isotopes typically found in Marcellus wastewater. Although treatment significantly reduced radium and barium levels in the wastewater, the amount of radioactivity accumulated in the river sediments still exceeds thresholds for safe disposal, Vengosh said.
Years of wastewater disposal with high radioactivity has “created potential environmental risks for thousands of years to come,” Vengosh said.
Industry has made efforts to reuse or to transport shale gas wastewater to deep injection wells, but wastewater is still discharged to the environment in some states.
Drilling waste is exempt from both federal hazardous waste regulations and the Safe Drinking Water Act. Oversight is left up to states, including New York and Pennsylvania, which have no standards or protocol to test drilling waste for radioactive material.
According to journalist Tom Wilber, author of Under the Surface, the NYS Department of Health sent a memo to the Department of Environmental Conservation in 2008 warning of the dangers of radioactive flowback.
“The memo, unreleased to the public, referenced an analysis of wastewater samples by state health officials that found levels of radium-226, and related alpha and beta radiation up to 10,000 times higher than drinking water standards,” Wilber reported in a post on his blog, “Shale Gas Review,” in February, 2013. “Based on that finding, the Health Department urged the DEC to design a testing protocol to ensure hot drilling waste is handled and disposed of properly.”
The Duke team published its findings Oct. 2 in a peer-reviewed journal, Environmental Science & Technology.
The Josephine treatment facility is about an hour east of Pittsburgh. Blacklick Creek is a tributary of the Conemaugh River, which flows into the Allegheny River, a water source for numerous cities, including Pittsburgh.
The study was funded by the Nicholas School and the Park Foundation of Ithaca, NY.