DOES HYDRO-FRACKING AFFECT LOCAL SURFACE WATERS? A TEST FOR CHEMICAL SIGNATURES

Hydraulic fracturing (“hydro-fracking”) is an increasingly common method of extracting natural gas from the geologic deposits of the Appalachian region. This method injects highly pressurized fluids into hydrocarbon-containing reservoir rocks in order to accelerate the extraction of hydrocarbons such as methane and petroleum compounds.

Hydro-fracking is controversial because of its potential impact in the contamination of ground waters and surface waters. Several previous studies have raised concern that this is a problem. However, it is often difficult to conclusively prove that a particular hydro-fracking operation is in fact causing contamination.

Hydro-fracking operations are widespread in several watersheds to the Northwest of the University of Tennessee. In many cases, these watersheds are relatively pristine and still maintain a very rich aquatic biodiversity. This would include the South Fork of the Cumberland River, Clear Fork, the Clinch River and the Powell River.

We examined the hypothesis that hydro-fracking operations can be detected in downstream surface waters using chemical analyses. If true, this could be a very useful tool as an environmental indicator to study the impact of these increasingly common operations. We took water samples from several areas downstream of hydro-fracking operations and analyzed them for traces of methane and other hydrocarbons, heavy metals including arsenic, biocides and detergents. Water samples were analyzed with gas chromatography, inductively coupled plasma and a field meter. Our findings are very tentative but they are suggestive of the possibility that a geochemical signature may in fact exist although much further work is required.