A new study by researchers at Duke University suggests that people whose homes are located near fracking sites are exposed to a higher risk of having their drinking water contaminated.
Researchers looked into samples from more than 140 private wells located in the vicinity of the actively exploited Marcellus shale in the northeastern part of Pennsylvania. Results revealed that methane was present in concentrations higher than safe levels in 82 percent of water samples, with the average level detected reaching six times higher than normal if the well was situated within a kilometer of a drilling well.
The study, published in the Proceedings of the National Academy of Sciences, also discovered the presence of high levels of ethane and propane in drinking water. For wells located not further than a kilometer from a shale gas drilling site, the concentration of ethane reached 23 times the normal level. Propane was found in a total of 10 wells located within the same distance from a drill site.
Robert Jackson, a professor of environmental sciences at Duke's Nicholas School of the Environment and leader of the study, commented that researchers did not expect to find such high concentration levels of combustible gases and were surprised by the strong impact that vicinity to drilling sites had on drinking water. He stated that there was no biological source of either gas in the area which could have affected samples of drinking water and that the results were conclusive that the contamination was linked to fracking.
According to Dr. Georges Benjamin, executive director of the American Public Health Association in Washington, D.C., the presence of these gases in drinking water posed a serious risk of fire and explosions that could affect the public. All these gases are extremely volatile and if they leak into a closed space, such as homes, there is a high risk of a blast, he went on. Benjamin explained that based on scientific evidence known so far there was no risk involved with ingesting the gases by drinking the water because, for them to have an effect, one would need to drink immense amounts of water, which is hardly likely.
The link between water contamination and fracking as a method for extracting shale gas and oil is not new. Jackson believes that the contamination may be a result of inadequate well construction which allows gases to escape the steel tubing or the concrete seal that encloses it. He rejected the possibility that gases may be seeping through many feet of rock and reaching water wells.
Jim Smith, spokesman for the Independent Oil and Gas Association of New York, claimed that the Duke University study had several major flaws, such as the fact that water samples were not randomly taken but water was sampled from wells that were selected by researchers and local homeowners' associations. In addition, he noted that the study did not find any fracking fluid present in the contaminated wells, which suggested that the gases may not have originated from fracking wells.