Does hydrofracking contaminate water?

The experts from Duke analysed 141 drinking water samples from private water wells across Pennsylvania’s Marcellus shale basin.

Their findings concluded both higher methane concentrations in local drinking water within a kilometre of the drilling site and higher ethane and propane concentrations.

There is no biological source of ethane and propane in the region and Marcellus gas is high in both

Duke University professor Robert B. Jackson

In tests conducted on water within a kilometre of the shale site, researchers found methane concentrations 6 times higher, whereas ethane concentrations were 23 times higher.

Elements of propane had also been detected in 10 of the 141 samples taken from drinking water within the area.

“The methane, ethane and propane data, and new evidence from hydrocarbon and helium isotopes, all suggest that drilling has affected some homeowners’ water,” stated Robert B. Jackson, a professor of environmental sciences at Duke’s Nicholas School of the Environment.

“There is no biological source of ethane and propane in the region and Marcellus gas is high in both, and higher in concentration than the Upper Devonian gas found in-between,” he added.

The team examined several factors which could explain their findings but Jackson believed that distance to gas wells was the most significant factor influencing gases in the drinking water sampled.

The findings, published in ‘Proceedings of the National Academy of Sciences’, argued that distances from fracking sites can play  a major role in determining the possible risk of groundwater impacts from shale developments.

The researchers believe their collected helium data, used to identify contaminations with noble gas isotopes, will benefit future studies and enable a high degree of certainty when analysing trace contaminants.