Earlier this week PNAS published a study that documents a link between hydraulic fracturing and water contamination. A team of Duke researchers showed that water wells located close to active drilling sites had methane levels 17 times higher than water wells located further away. Their definition of active drill site: within 3280 feet of a well.
The scientists tested 68 drinking water wells in the Marcellus and Utica shale drilling areas in northeastern Pennsylvania and southern New York State. They measured dissolved salts and other constituents (carbon, boron and radium) as well as methane levels.
The average methane concentration in drinking water was high enough – over 28 milligrams per liter (mg/L) – to qualify for hazard mitigation as recommended by the US Office of the Interior. But some water had much more methane – up to 64 mg/L.
Though the researchers did not find evidence of fracking chemicals in the water wells, they expressed concern for that they see is a clear correlation between drilling activity and methane migration into drinking water. The presence of methane demonstrates that pathways do exist for migration of other potential contaminants.
Even more interesting were the recommendations they made in a White Paper accompanying their study.
- Initiate a medical review of the health effects of methane.
- Create a national database listing methane, ethane and propane concentrations in drinking water.
- Find out how methane is getting into drinking water, say the scientists. Is methane contamination due to poorly constructed well casings? Or is the process of fracking creating pathways for methane and other chemicals to migrate to the surface?
- Develop better estimates for greenhouse gas emissions of methane associated with shale gas extraction.
- Conduct extensive baseline water testing prior to exploration and drilling. They recommend testing water at least 3,000 feet from well sites and that testing be conducted by independent state-certified labs.
- Better study of waste treatment. For drilling fluids going to wastewater treatment facility, regulators need to understand how much of the chemicals are removed in the waste treatment plants and what are the long-term ecological effects downstream.
- Regulate fracking under the Safe Drinking Water Act (SDWA).
- Fully disclose chemicals used in hydro-fracking.