- Buyer's guide
Hydrofracking changes water wells
Methane is flammable and poses a risk of explosion. In very high concentrations, it can cause asphyxiation. Little research has been conducted on the health effects of drinking methane-contaminated water and methane isn't regulated as a contaminant in public water systems under the EPA's National Primary Drinking Water Regulations.
The Duke team collected samples from counties overlying the Marcellus shale formation. Accelerated gas drilling and hydrofracking in the region in recent years has fueled concerns about well-water contamination by methane, produced water and fracking fluids, which contain a proprietary mix of chemicals that companies often don't disclose.
Shale gas comprises about 15 percent of natural gas produced in the United States today. The Energy Information Administration estimates it will make up almost half of the nation's production by 2035.