Assessment of Baseline Groundwater Quality and Unconventional Development of Hydrocarbons: The Science and the Belief

Opponents to unconventional hydrocarbon development in the last five years have developed a compelling narrative that potable waters may be broadly contaminated by methane and various solutes derived from the industrial practice. This narrative cleverly incorporated video, such as the documentary Gasland, investigative newspaper reports, and some peer-reviewed scientific publications based on small data sets. While local contamination may be technically “possible,” is it scientifically plausible or probable? 

To what extent is this belief reality? What evidence actually shows drilling for unconventional hydrocarbons causes meaningful contamination above and beyond natural water chemical variability in the Appalachian Basin? In my talk I show there has been minimal harm to potable waters from unconventional hydrocarbon development compared to that caused by other acceptable industrial practices. I arrive at my conclusion from the basic principles of hydrogeology, physics, and chemistry, and analysis of more than 30,000 baseline samples collected where drilling already has been most intense in Pennsylvania and Ohio.

Baseline sampling, if done, should focus on halogens (Cl, Br, I), not major solutes such as sodium, trace metals such as iron and barium, nutrients, or fecal coliform bacteria, to assess possible solute contamination from oil and gas development. A forensically viable suite of VOCs and SVOCs associated with hydraulic fracturing could be explored to assess changes in methane concentrations if they occur beyond reasonable variability in native waters. This suite needs to be designed to sample those compounds that do not biodegrade too fast to be seen, and to avoid cross contamination by materials used during the drilling of production wells.