New scientific sampling and analysis has found high concentrations of ammonium and iodide, two potentially hazardous pollutants, in oil and gas well drilling wastewater discharged into streams and rivers in Pennsylvania and other states.
The peer-reviewed study, which will be published this week in the journal Environmental Science & Technology, is the first to identify those contaminants as widespread in the wastewater discharges from spills and treatment plants, including three facilities in the Allegheny River watershed.
The findings raise new concerns about the environmental and health impacts of drilling wastewater discharges from shale and non-shale oil and gas drilling operations in a variety of geological formations in the Appalachian Basin, according to Avner Vengosh, a professor of geochemistry and water quality at Duke University’s Nicholas School of the Environment. He is one of six researchers from Duke, Stanford and Dartmouth universities who worked on the study.
Mr. Vengosh, in an email response to questions Tuesday evening, said the study did not directly measure the two chemicals -- ammonium and iodide -- in public water treatment plants, but cites a recent report that showed that "even a tiny amount of bromide and iodide can trigger the formation of disinfection byproducts in public water supplies upon disinfection of the water."
Ammonium, when dissolved in water, can convert to ammonia, which is toxic to aquatic life. Sampling at wastewater discharge sites found ammonium concentrations up to 100 milligrams per liter or more than 50 times higher than the federal water quality limit for protecting aquatic life.
For the study, researchers collected samples of wastewater from both conventional and unconventional shale gas and oil wells in Pennsylvania and New York, from hydraulically fractured wells in Pennsylvania and Arkansas and from treatment plant discharges into rivers and streams at three Pennsylvania disposal sites in Venango and Indiana counties.
The sampling found that levels of ammonium and iodide in fracking fluid wastes and conventional oil and gas drilling wastewater can be equally high.
The study, titled, “Iodide, Bromide, and Ammonium in Hydraulic Fracturing and Oil and Gas Wastewaters; Environmental Implications,” was funded by the National Science Foundation and the Park Foundation.
Don Hopey: email@example.com or 412-263-1983. Twitter: @donhopey.