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Chloride Concentrations in Recovered Hydraulic Fracturing Fluid Increase With Depth of Tank

Photo of Sampling tank-stored fracing fluids. Pam Edwards, Forest ServiceSampling tank-stored fracing fluids. Pam Edwards, Forest ServiceSnapshot : The hydraulic fracturing fluid used in natural gas extraction in the northeastern Appalachians raises concerns about safe disposal. Forest Service scientists are studying the chemistry of the recovered injected fluid, called flowback, which often contains high concentrations of chloride. They found that the concentrations increase with the depth of the storage tank and that results of laboratory analysis are more accurate than those from field test kits.

Principal Investigators(s) :
Edwards, Pamela 
Research Location : Appalachians
Research Station : Northern Research Station (NRS)
Year : 2011
Highlight ID : 314


Natural gas production has increased in recent years in the northeastern Appalachian forests. The natural gas generally is extracted by a procedure known as hydraulic fracturing or fracking. A mixture of acids, water, gasses, and other additives is injected under high pressure into the bore hole to fracture the bedrock and thus releasing the natural gas. Once fracturing is completed, a portion of the injected fluid, called flowback, is recovered and stored in open pits or tanks. Because flowback often has high chloride concentrations, it is important that flowback chemistry is properly characterized so that disposal can be carried out safely. Forest Service scientists tested two technologies that measure chloride concentrations and determined that the concentrations increased with the depth in the tank. They also found that laboratory analyses were more accurate than field test kits.

Forest Service Partners

External Partners

  • Berry Energy Corporation

Program Areas