Groundwater monitoring for methane required near energy wells

April 5, 2017
Researchers have found methane gas can travel far in groundwater, posing a safety risk. Photo credit: Aaron Cahill.

A study published in Nature Geoscience indicates that when methane leaks from energy resource development such as fracking it is highly mobile in groundwater, potentially travelling far beyond a leaky well and posing a safety risk.

“Currently monitoring for gas leakage is conducted at ground surface next to an energy well, while the surrounding groundwater underneath isn’t usually monitored,” says lead author Aaron Cahill, a UBC researcher who conducted the study during his time as a Postdoctoral Fellow at the University of Guelph.

Besides posing an explosion risk and degrading groundwater quality, methane can contribute to climate change when released to the atmosphere. Ordinarily, researchers have focused on finding out if methane has leaked in an area, and finding the source of the leak. But Cahill and his colleagues took a different approach. They released a small amount of gas into the sub-surface and observed how it moved, how it impacted groundwater, and where it ended up. They discovered methane dissolved extensively into the groundwater.

John Cherry, a groundwater contamination expert with the University of Guelph who co-authored the study, says sealing energy wells thoroughly can be challenging and leaky wells are common. Even when leaks are fixed, the impact to groundwater is likely long-term.

“We require a more comprehensive approach which monitors both surface and groundwater for methane,” Cahill concluded.

The study has just been showcased in a feature article by UBC Science: