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Fracking Initiates Bromide and Sulfate Testing of Groundwater

Hydraulic fracturing, often called fracking, uses high-pressure water, sand, and chemicals to obtain hard-to-reach natural gas and oil from rocks deep underground. Although the process has been used for decades, concerns continue over the possibility of operations contaminating groundwater and drinking water. Hydraulic fracturing is done from a wellbore drilled into reservoir rock formations, and uses many chemicals and millions of gallons of water under pressure in the process. A 2011 report to the U.S. Congress stated that companies have used up to 750 chemicals as additives for hydraulic fracturing between 2005 and 2009.

Hydraulic fracturing in the U.S. is essentially unregulated. The U.S. Congress exempted fracturing fluid from regulation in the Safe Drinking Water Act of 2005, thereby excluding it from the EPA’s jurisdiction. However, the EPA announced in June 2011 that it will examine claims of water pollution related to hydraulic fracturing in several U.S. states. Texas and California are proposing fracking regulations that would require companies disclose their fracking locations, chemicals used, and the amount of water pumped. Canada, Australia, and other countries also conduct fracturing operations.

According to the U.S. EPA, hydraulic fracturing has resulted in increased salts, chloride (Cl), bromide (Br), and sulfate (SO4) in ground and surface waters. The presence of increased bromide in water can lead to the formation of increased disinfection byproducts, bromate, and trihalomethanes (THMs). Bromate is typically formed during the ozonation of water containing bromide, while THMs are formed during chlorination. THMs can be chlorinated and/or brominated. The presence of bromide can lead to increased brominated THMs which are inherently more toxic. Results presented at the 2011 Water Quality Technology Conference (WQTC) reported increased forms of brominated THMs from locations in the Alleghany River known to be impacted by water from hydraulic fracturing activity and where feedback waters are taken to publicly owned treatment works (POTWs) for treatment. POTWs are not designed to minimize the contaminants from hydraulic fracturing solutions. According to the U.S. EPA, over 100 compounds can be found in hydraulic fracturing solutions. In response to environmental concerns, the EPA has drafted a study plan to understand the potential effects of hydraulic fracturing on drinking water sources.

Customers, including water authorities, testing service companies, and fracking water processing facilities, have begun testing for bromide and sulfate, markers for groundwater salt contamination. Thermo Scientific Dionex Reagent-Free* IC (RFIC*) systems, including the ICS-5000, ICS-2100, ICS-1600, and ICS-1100, are recommended for environmental work because they provide the required sensitivity for the marker ions bromide and sulfate.

For groundwater analysis, ICS systems are being used with the Thermo Scientific Dionex IonPac* AS22 column under isocratic conditions where bromide and sulfate concentrations are at parts-per-million (ppm) levels. This method is being used by a water authority for monitoring bromide in a local river near a fracking site.

For wellbore fluid, a method is in development using the Dionex ICS-2100 system and the Dionex IonPac AS19 hydroxide-selective anion-exchange column. Gradient conditions using potassium hydroxide eluent generation are essential to separating high chloride levels from bromide and sulfate. The Dionex IonPac AS19 column was originally designed for analysis of trace anions in drinking water and meets the performance requirements of EPA Methods 300.0 and 300.1.

An alternative to eluent generation, the Dionex RFIC systems also incorporate eluent regeneration (ER) for consistency and ease of operation for applications dedicated to the analysis of anions like bromide or sulfate in samples with low to moderate-concentration matrices. These systems use a suppressor to regenerate returning eluent, allowing a single preparation of eluent to be used for up to four weeks.

Have questions about systems, methods, or analytes in hydraulic fracturing? Contact us at envreport@dionex.com.

Related Application Notes:
AN 154: Determination of Inorganic Anions in Environmental Waters Using a Hydroxide-Selective Column
AB 133: Cost-Effective Determination of Inorganic Anions and Cations in Municipal Drinking Water Using Capillary Ion Chromatography
White Papers
Bromide Analysis for Hydraulic Fracturing
The Importance of Anion and Organic Acid Determinations in Fracking Wastewater by Ion Chromatography
Technical Notes
TN 139: Determination of Anions in Fracking Flowback Water From the Marcellus Shale Using Automated Dilution and Ion Chromatography
TN 138: Accurate and Precise Automated Dilution and In-line Conductivity Measurment Using the AS-AP Autosampler Prior to Analysis by Ion Chromatography