Duke University scientists have discovered high levels of two potentially hazardous contaminants, ammonium and iodide, in wastewater being discharged or spilled into streams and rivers from oil and gas operations in Pennsylvania and West Virginia. The presence of these toxic substances — which can have devastating effects on fish, ecosystems, and potentially, human health — in fracking wastewater was unknown until now, sparking new questions about the safety of this burgeoning industry.
“This discovery raises new concerns about the environmental and human health impacts of oil and gas wastewater in areas where it is discharged or leaked directly into the environment,” said study co-author Dr. Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment. “Our data clearly show that the current brine treatment practice in Pennsylvania is not sufficient to remove these contaminants.”
The findings have major implications for whether stronger regulations are needed to curb water pollution from fracking and other oil and gas industry operations. Over the years, the industry has faced questions about issues such as unsafe well design that allows methane to seep into drinking water, and about lubricants and other chemicals it adds to fracking water. Despite industry-backed claims that fracking poses no significant health hazards, a 2014 review of health-related studies on fracking concluded that the current scientific research puts forward “both substantial concerns and major uncertainties to address.”
Now, added to the list of concerns are ammonium and iodide – two naturally occurring, dangerous chemicals that could pose serious risks to human and environmental health.
When dissolved in water, ammonium can convert into ammonia, which is highly toxic to aquatic life. The scientists detected ammonium levels of up to 100 milligrams per liter in oil and gas effluents they collected at the wastewater discharge sites. Those levels are more than 50 times higher than the EPA water-quality threshold for protecting freshwater organisms. Meanwhile, elevated iodide in surface water can promote the formation of highly toxic byproducts in drinking water when the iodide mixes with the chlorine used to disinfect the water at municipal treatment plants located downstream from oil and gas operations. Such disinfection byproducts are not monitored by state or federal agencies.
The new peer-reviewed study, appearing this week in the journal Environmental Science & Technology, is the first to document the presence of high levels of ammonium and iodide in oil and gas wastewater. While concerns about water contamination have primarily focused on the impact of fracking fluids from shale gas exploration, the new findings show that wastewater from conventional oil and gas exploration contains levels of ammonium and iodide that are just as high.
“Wastewater from both conventional and unconventional oil and gas operations is exempted from the Clean Water Act, which allows their disposal to the environment,” said Dr. Vengosh. “This practice is clearly damaging the environment and increases the health risks of people living in these areas, and thus should be stopped.”
Although both types of oil and gas operations produce wastewater with pollutants that can harm human health, the unconventional process of hydraulic fracturing — which involves injecting thousands of gallons of water, sand, and chemicals underground to crack shale rock — produces much more wastewater than its conventional counterpart. Nationwide, fracking produces an estimated 280 billion gallons of wastewater per year, according to an Environment America report.
How to dispose of that polluted water remains a major challenge for oil and gas companies that use the technique. Some gets stored in artificial ponds, some is injected underground, and some is treated and put back into rivers. None are foolproof systems — untreated fracking wastewater has spilled into the environment multiple times from both injection wells and ponds, and treated wastewater has been found to be harmful for human consumption.
Regardless of the disposal technique, Dr. Vengosh and his team say the discovery of two new, toxic pollutants in fracking wastewater highlights the increasingly clear threat to human health and the environment.
To reach their conclusions, the researchers collected and analyzed 44 samples of waters produced from conventional oil and gas wells in New York and Pennsylvania and 31 samples of flowback waters from hydraulically fractured shale gas wells in Pennsylvania and Arkansas. They also collected and analyzed oil and gas effluents that were being directly discharged into streams, rivers and surface waters at three disposal sites in Pennsylvania and a spill site in West Virginia.
Increasing evidence of fracking dangers
Their discovery of ammonium and iodide adds to a growing list of potentially harmful contaminants that have been found in drilling wastewater. In September, Dr. Vengosh and a team of researchers from Duke found that heavy metals and salts called halides — which include bromide and chloride — are present in wastewater. Those too can promote the formation of toxic disinfection byproducts when disinfectants used in water treatment plants react them, according to the Environmental Protection Agency.
Previous studies have shown that fracking fluids contain high levels of salts, barium and radioactive elements, in addition to man-made chemicals added in the process of hydraulic fracturing. While additives make up only 2 percent of the total fluid volume, this can represent a staggering 40,000 liters of additives injected per well. A previous analysis of 353 of these chemicals found that more than 75 percent could have respiratory, gastrointestinal, dermatological, and ocular effects; 40 percent to 50 percent could be neuro-, immuno- and nephrotoxic; 40 percent could be endocrine disruptors, and 25 percent could be carcinogenic.
Dr. Vegnosh and colleagues conclude by emphasizing the urgent need for further studies of these issues, joining the more than 90 medical and public health professionals, and 25 professional organizations, who recently co-authored a statement urging lawmakers to delay approval of further fracking operations until additional research on the human impacts is carried out.
The American Public Health Association, along with the National Center for Environmental Health and the Agency for Toxic Substances and Disease Registry—both affiliated with the U.S. Centers for Disease Control and Prevention in Atlanta—and the U.S. Government Accountability Office, have all separately expressed concern about the current lack of understanding regarding the cumulative public health impacts posed by drilling and fracking.
The past few years have seen a dramatic increase in the amount of recent research into fracking impacts, but the evidence is only now starting to catch up with the industry. In December 2014 alone, three separate analyses of the science reached similar, alarming conclusions about the health and environmental risks of fracking. The provincial government of Quebec indefinitely extended its own moratorium on fracking, based on health and environmental concerns as detailed in a 540-page report. In a statistical analysis of the evidence, Physicians Scientists & Engineers for Healthy Energy found that a large majority of the approximately 400 peer-reviewed papers on drilling and fracking indicate dangers. And Concerned Health Professionals of New York released an updated compendium on the risks and harms of fracking to health, water, air, wildlife, and economic vitality, determining that there is no evidence that fracking can be done safely, but a great deal showing harms.
“A nation that poisons its soil, poisons itself.”
– President Theodore Roosevelt