Can hydraulic fracturing for oil and gas cause groundwater contamination? This is the question I have been waiting to find out from the U.S. Environmental Protection Agency’s hydrofracturing scientific investigation and studies. Of course if you have a spill, there is always the potential for contamination. But does the actual process of inducing fractures through injecting water and chemical additives under pressure down a well actually cause contamination, either from the hydrofracturing fluid or natural gas migrating into the groundwater. I’ve read through the Environmental Protection Agency’s “Draft Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources.” I didn’t have to read all 998 pages, just the Executive Summary and the Chapter on Injection. The answer is there are documented cases where the hydrofracturing process itself has contaminated groundwater. Incidences, as the Environmental Protection Agency has stated before, are rare. The evidence comes primarily from the case studies that the Environmental Protection Agency conducted. They have released the case studies as well as the Draft Assessment and I plan to take a look at the case studies in the next few weeks and provide more information on how they determined contamination did or did not come from the hydrofracturing process.
The Environmental Protection Agency always does a good job on their reports. The Draft Assessment is an excellent compilation of the scientific literature on the subject. They have summarized dozens of published research papers. As you can imagine, there has been a lot of recent research in the area of hydraulic fracturing and its possible impact on drinking water. The Draft Assessment also looks at data on well construction and practices. This data was gathered through a survey of service companies that perform hydraulic fracturing for oil and gas companies. The Environmental Protection Agency used the collected data to determine what practices are being used to protect groundwater. As advertised in the Study Plan for the current report, a numerical model was conducted and has been published in the scientific literature. I hope to get a copy of that in the next few months and take a look at it.
The Environmental Protection Agency also gives a litany of possible ways natural gas and chemicals from fracturing fluid could enter the groundwater. These include everything from poor cementing of the casing protecting groundwater to casing failure during hydrofracturing. You could say that the Environmental Protection Agency has validated Murphy’s Law: anything that can go wrong will go wrong.
Right now the Draft Assessment is undergoing review. With the amount of scientific literature quoted in the report, the review needs to be conducted before I write anything further on the Assessment Report as interpretations made in the report may change. So I’m going to concentrate on reviewing and writing about the case studies while that process is ongoing.