Hydraulic fracturing can contaminate drinking water: study
As the Nova Scotia (N.S.) government conducts a review of the environmental effects associated with hydraulic fracturing, a new study by scientists at Duke University found that the drilling technique, which is used to free natural gas trapped in shale rock formations, can contaminate drinking water.
The study - "Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing" - collected data from groundwater tests conducted at 68 private drinking water wells in the Marcellus and Utica shale drilling areas from 36- to 190-m deep in northeastern Pennsylvania and southern New York State.
Of those 68 wells, 60 were tested for dissolved methane. (All wells were analyzed for, among other things, dissolved salts, water isotopes and isotopes of dissolved constituents - carbon, boron, and radium.)
The study found methane concentrations in 51 of the 60 wells.
The study also determined that the wells in active drilling and extraction areas contained, on average, 17 times more methane than the wells in non-active drilling areas.
Though "dissolved methane in drinking water is not currently classified as a health hazard for ingestion, it is an asphyxiant in enclosed spaces and an explosion and fire hazard," said the study.
John Bennett, executive director of Sierra Club Canada, told EcoLog News that the results of the study show that hydraulic fracturing can be harmful to people and the environment.
As a result, provincial governments looking to embrace this drilling technique need to review it to determine its health and environmental effects, said Bennett.
This would allow them to develop the necessary mitigation measures, he added.
In April 2011, the N.S. government began a review of hydraulic fracturing in the province in response to public concerns over its effects on, among other things, water.
To date, three companies - Allied Petroleum Exploration Inc., Triangle Petroleum Corporation and PetroWorth Resources Inc. - intend to use hydraulic fracturing in N.S.
The review is examining:
- the effects of hydraulic fracturing on groundwater and surface water
- the effects of hydraulic fracturing on land, such as potential soil contamination
- waste management, including surface ponds of produced waters
- management of additives in hydraulic fracturing fluids
- site restoration
- financial security and insurance.
N.S. Department of Environment Spokesperson Karen White told EcoLog News that the N.S. government will consider the Duke University study as part of its hydraulic fracturing review, which is expected to be completed by early 2012.
The study, which was recently published in the Proceedings of the National Academy of Sciences in May 2011, is available here.
To read another article like this, visit:
"Canada and Quebec Accord on Que's offshore resources", EHScompliance.ca newsletter, April, 2011.
"NS to review fracking hazards", EHScompliance.ca newsletter, April, 2011.
"Quebec puts brakes on shale gas development", EHScompliance.ca newsletter, March, 2011.