Those who believe their drinking water wells may be contaminated with methane released by natural gas fracking may be wrong, according to a West Virginia University professor.
"The source of methane gas can range from active or inactive deep coal mines, landfills, gas storage fields or microbial gas generated in a shallow subsurface," said assistant professor Shikha Sharma, noting that dissolved methane gas already exists in groundwater where there is no shale gas drilling.
"As a scientist, it is my job to stay focused on the scientific perspective of this study while staying neutral on the political and social issues associated with it," she added.
In the midst of a study on the origins of methane gas in the Monongahela River watershed and other areas of this region, Sharma stops short of saying that fracking, or hydraulic fracturing of the shale, absolutely does not release methane into groundwater.
"Depending on how and where this methane is formed, it can have very different C and H isotope signatures. This gives us the ability to know if it comes from hydrofracking releases or some other source," she said.
Fracking occurs after companies finish the drilling portion of natural gas development. Millions of gallons of water, sand and chemicals are pumped more than a mile into the ground at high pressure in order to shatter the rock, thereby releasing the gas.
Last year, Marshall County resident Jeremiah Magers believed fracking by those working for Chesapeake Energy caused his drinking water well to become contaminated with methane.
Chesapeake officials said they collected samples from Magers' water source. They informed him that dissolved methane gas was detected in his water sample, but that methane gas may be generated from various sources.
Earlier this year, however, the Pennsylvania Department of Environmental Protection fined Chesapeake $900,000 for apparently causing methane to be released into private water wells in the northeastern portion of the state, near New York. Environmental department officials said improper well casing and cementing by Chesapeake in shallow zones allowed methane to migrate into groundwater, thus polluting the drinking water supply. The fines included a $700,000 civil penalty and a $200,000 deposit into the Keystone State's well plugging fund.
With the jury still out on whether fracking can release methane into groundwater, Sharma continues her study. It is being funded by a $25,000 grant from the U.S. Geological Survey, provided through the West Virginia Water Research Institute. This money allows Sharma and her graduate student, Michon Mulder, to gather and test water samples from groundwater wells in the Monongahela River watershed.
The study will allow the researchers to construct a picture of existing methane gas sources in the area, which could then be used to identify dissolved methane releases associated with Marcellus Shale gas drilling.
"There are some concerns associated with higher levels of dissolved methane," said Sharma. "The levels of dissolved methane higher than 28 milligrams per liter are considered potentially flammable. Because dissolved methane already exists in some of our samples, we need to figure out where the actual sources of this dissolved methane gas are located.
"It is important to understand exactly how much methane exists in the groundwater now and what sources it comes from, so that unbiased decisions can be made regarding the potential and real impacts of hydrofracking on our water sources in the future," she added.