More evidence for (and against) groundwater contamination by shale gas

Shale gas well pad in Pennsylvania.

Robert B. Jackson

Few topics in the realm of energy are as publicly charged today as fracking, the process by which natural-gas-bearing layers of shale are hydraulically fractured to create pathways for the gas to be extracted. To some, it’s simply a major boon to the US economy and energy independence. To others, it’s a short-sighted resource grab that will leave drinking water resources poisoned for decades. As research in areas where fracking is already prevalent has slowly plodded ahead, what we’ve learned hasn’t fit neatly into either of the black-and-white narratives of the political debate. The realities have, unsurprisingly, been complicated.

A pair of recent papers provides an example, finding different results in areas of Pennsylvania and Arkansas where shale gas is currently being produced.

Problems in Pennsylvania

The first provides an update to an earlier study in northeastern Pennsylvania, where the Marcellus Shale has been a hot target for the natural gas industry. That study analyzed water samples from 68 private wells; methane gas was found to be more prevalent in wells close to shale gas extraction sites. The work implied that the natural gas wells were somehow enabling the migration of natural gas upwards into the drinking water aquifer.