Six scientists from Duke, Stanford and Dartmouth Universities worked on the peer-reviewed study that was published today in the journal Environmental Science & Technology. Their findings raise renewed concerns over the health and environmental impacts resulting from the discharge of wastewater from conventional and fracking oil and gas operations into rivers and streams.
For a number of years, the oil and gas industry has faced questions over the unsafe construction of wells that allow methane to seep into groundwater. And with the increase in the use of hydraulic fracturing fluids in shale gas production, the safety of drinking water has become an even greater concern.
The research team took samples of wastewater from conventional and unconventional shale gas and oil well sites in Pennsylvania and Arkansas, as well as treatment plant discharges going into rivers and streams at three disposal sites in Venango and Indiana counties in Pennsylvania. They also included spill site in West Virginia. They found the levels of ammonium and iodide were equally the same, regardless of the method of oil and gas extraction used.
When ammonium is dissolved in water, it will convert to ammonia, making it toxic to aquatic life. Some of the samples obtained from wastewater discharge sites had ammonium levels of 100 milligrams per liter. This is more than 50 times higher than the federal guideline for water quality limits in protecting aquatic life.
Iodide is also hazardous, especially when it mixes with chlorine used in disinfecting water at water treatment plants. The disinfection by-products have toxic and carcinogenic effects, and most of them are not being monitored by state or federal authorities. What is even more preposterous is that under a 2005 energy law loophole created by Congress, wastewater from fracking is not even regulated under the U.S. Safe Drinking Water Act.
“We are releasing this wastewater into the environment and it is causing direct contamination and human health risks,” said study co-author Avner Vengosh, professor of water quality and geochemistry at Duke’s Nicholas School of the Environment. “It should be regulated and it should be stopped. That’s not even science; it’s common sense.”
Fracking produces from one to two million gallons of wastewater per well. Conventional wells produce less wastewater, but the ammonium and iodide contamination is about the same, Vengosh said. “Fracking fluids are not much different from conventional oil and gas wastes,” said Jennifer Harkness, lead author of the study and a doctoral student at Duke.
The study was funded by the National Science Foundation and the Park Foundation.