RANKING RISK TO WATER RESOURCES OF CHEMICAL CONTAMINANTS FROM SHALE GAS DEVELOPMENT

The public in communities where shale gas development is occurring or may occur are usually highly concerned about potential contamination of ground water supplies from chemical contaminants in hydrofracturing fluids or in natural gas that may leak into aquifers during production. A U.S. Congress sub committee on energy and commerce produced a report published in 2011 that specified 29 primary contaminants in hydraulic fracturing fluid, although some of these contaminants were themselves complex chemical mixtures, and some proprietary chemicals were not listed. Additional contaminants may be present in natural gas that may be site specific. However, the true risk of contaminants reaching groundwater depends on transport properties (i.e., sorption to soils and other chemical reactions), degradation potential, toxicity, and concentration in ground water. To date, a quantitative analysis to determine the mobility and persistence of the various contaminants has not been published. This work presents a ranking of the top organic contaminants based on these factors. The information can be used to develop monitoring and accident response plans in shale-gas development areas.