You don’t have to be a hydrogeologist to understand the severity of the U.S. Geological Survey’s most recent warning. As the number of suitable sites for deep wastewater injection wells dwindles, and production in the Marcellus ramps up, pressure is mounting on municipal water treatment plants to deal with all the frack waste. But as every good sewage plant operator knows, what goes in, must come out.
Technical Announcement: Disinfection of Energy Wastewater Can Lead to Toxic Byproducts
Contact Information:
U.S. Department of the Interior, U.S. Geological Survey
Office of Communications and Publishing
12201 Sunrise Valley Dr, MS 119, Reston, VA 20192
Mike Focasio 703-648-6808
Alec Demas 703-648-4421
Released: 9/4/2013 — Wastewater treatment plants that process waters from oil and gas development were found to discharge elevated levels of toxic chemicals known as brominated disinfection byproducts, according to a new study by the U.S. Geological Survey.
Disinfection byproducts are created by chemical reactions when water is disinfected. Of the hundreds of known, or suspected, disinfection byproducts possibly created by disinfection processes, the brominated forms are among the most toxic.
“While these findings do not indicate an immediate threat to aquatic life or human health, the study provides new data on the water quality of streams receiving discharged wastewater that can be used to inform decisions about management and treatment of produced waters,” said Michelle Hladik, primary author of the report.
Waters that are co-produced when oil and gas resources are extracted from deep geological formations are commonly called produced waters. Produced waters are composed of naturally occurring materials characteristic of the geologic formations in which they originate. Often, the water in these formations is a brine with high concentrations of bromide, iodide, and other ions such as sodium and chloride.
Produced waters can originate from unconventional (e.g. hydraulic fracturing) and conventional oil and gas extractions. Management of produced waters includes a variety of methods, such as recycling, road spreading, deep-well injection, and processing by wastewater treatment plants.
Several different types of brominated disinfection byproducts can be created when produced waters with high levels of bromide are disinfected.
Currently, and during the time of the study, most wastewaters from unconventional oil and gas activities such as hydraulic fracturing in the study area have been deep well injected and therefore not processed by wastewater treatment plants. However, this study did not attempt to quantify the relative proportions of produced waters originating from the various unconventional or conventional oil and gas extraction activities.
The study is entitled “Discharges of produced waters from oil and gas extraction via wastewater treatment plants are sources of disinfection by-products to receiving streams,” and is published in Science of the Total Environment. The study may be accessed online.
The USGS provides information on the quality of our environment; identifies emerging environmental issues; and provides information to aid decision-making by regulators, policymakers, industry and the public. To learn more about this study and other USGS Environmental Health research, please visit the USGS Environmental Health website or sign up for the USGS GeoHealth Newsletter.
Link: http://www.usgs.gov/newsroom/article.asp?ID=3682#.Uimi3uBOTHg
“Disinfection Byproducts from Treatment of Produced Waters”
Study Summary: Waters produced as a byproduct of oil and gas development were found to yield high concentrations of disinfection byproducts (DBPs) when treated. The U.S. Geological Survey (USGS) sampled stream waters upstream and downstream of the outfall of Publicly Owned Wastewater Treatment Works (POTWs), POTWs that receive and treat waters produced by conventional and unconventional oil and gas development, and commercial treatment plants that treat similar produced waters. The samples were analyzed for a range of DBPs and selected precursors. The study was designed to determine if produced waters resulted in elevated levels of DBPs in the streams to which the treated wastewaters were discharged.
The resulting data indicate that significantly higher concentrations of brominated DBPs are discharged in the effluents of commercial or publicly owned wastewater treatment plants that treat produced waters than POTWs that do not treat produced waters. The evidence strongly indicates that naturally high bromide levels in the produced waters react with other chemicals when the water is disinfected and these reactions form high levels of the brominated DBPs. This is the first time it has been shown that these activities contribute DBPs to streams where the wastewaters are discharged.
Of the hundreds of potential DBPs formed when water is disinfected the brominated forms have been shown to be among the most toxic. This study drew no distinction between produced waters from conventional oil and gas development techniques and unconventional oil and gas development techniques, such as hydraulic fracturing.
This study was funded by the USGS Toxic Substances Hydrology and Energy Resources Programs.
Link: http://toxics.usgs.gov/highlights/dbp/
Tags: Bromides, disinfection byproducts, USGS
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