DEP Says Gas Drilling Did Not Contaminate Susquehanna County Well Water
The Pennsylvania Department of Environmental Protection says a 16-month long investigation concluded that gas drilling did not cause nearby residential water wells to contain high levels of methane in Franklin Township, Susquehanna County.
Speaking to StateImpact last September at a protest in Philadelphia, Franklin Forks resident Tammy Manning said she was convinced gas drilling caused her water to go bad.
Manning says her well water began spewing like a geyser in December, 2011. She says the contaminated water made her granddaughter vomit, before the family realized it was unsafe to drink.
“We want the gas company to leave our area,” said Manning. “I just feel like in 20 years, instead of going to war over oil, we’ll go to war over water.”
But DEP spokeswoman Colleen Connolly says the gas company is not to blame. The agency’s decision was based on isotopic testing, which showed the methane “fingerprint” did not match the methane extracted from WPX Energy gas wells, which are about 6,000 feet from the contaminated private drinking water wells.
“The testing determined that the water samples taken from the private water wells contained gas of similar isotopic makeup to the gas in the water samples taken from Salt Springs State Park. Additionally, the water wells and spring exhibited similar water chemistry, including the constituent’s barium, iron, total dissolved solids (TDS), chlorides, manganese and aluminum. DEP’s testing also determined that the gas in the water samples taken from the private water wells was not of the same origin as the natural gas in the nearby gas wells.”
Salt Springs State Park well water and springs contain naturally occurring methane. The park is about a mile from the homes.
“Additionally, the water wells and spring exhibited similar water chemistry, including the constituent’s barium, iron, total dissolved solids (TDS), chlorides, manganese and aluminum. DEP’s testing also determined that the gas in the water samples taken from the private water wells was not of the same origin as the natural gas in the nearby gas wells.”
Connolly says there was no baseline testing conducted on the three Franklin Township wells. The DEP also used historical water data to reach their conclusions.
“Additionally, agency staff evaluated information from a nearby mobile home park public water supply file relating to the its abandonment of a water source in 1998 due to elevated levels of methane, chlorides and TDS. The mobile home park is located approximately 2.3 miles from Franklin Forks, and this water well exhibited similar water chemistry to that of the three residential water supplies being investigated.”
Isotopic testing and historical data are two ways to trace methane migration. But that area of the state has a complicated geology with shallow pools of methane. Drilling with poorly constructed well casings can create a pathway for the shallow pools of gas to migrate into the water supply. In that case, the isotopic “print” of the gas would not necessarily match the methane extracted from the deep Marcellus formation. That’s what the DEP determined happened in Dimock, Pa.
David Yoxtheimer, a hydrogeologist with Penn State who studies methane migration, says well construction is key to preventing contamination.
“That’s common for [the gas] to come from shallower formations,” says Yoxtheimer. “And so [the drillers] need to take extra precautions, otherwise the borehole acts as a conduit that allows the gas to migrate up vertically.”
Yoxtheimer says the naturally occurring thermogenic gas makes it tricky to trace the source of methane migration in Susquehanna County.
“Seventy-eight percent of wells in Susquehanna County have measurable methane unrelated to drilling so that further complicates the situation. It’s even more important to do pre-drilling testing.”
Because the Franklin Forks wells were about 6,000 feet from the drill sites, the company was not required to do baseline testing.
“Well bore integrity is the name of the game here,” says Yoxtheimer. “You can drill and not have water quality issues.”
Yoxtheimer says by his calculation, DEP has connected drilling to methane contamination in only 16 instances.
He says investigators can now use acoustic testing you determine whether or not the well-bore is acting as a conduit for stray gas.
“You can actually hear it hiss,” says Yoxtheimer.
WPX Energy has been providing water to the residents. A spokeswoman for the company says it hasn’t decided whether the water deliveries will continue. WPX Community Relations Manager Susan Oliver said through an email the company worked cooperatively with the DEP and did its own well integrity tests.
“WPX voluntarily provided potable water to the three residents throughout the investigation period,” said Oliver. “More than 80 tests to evaluate water quality and more than 55 tests to ensure the integrity of two WPX natural gas wells were performed as part of the investigation. We’re pleased that a science-based, fact-finding effort by the state definitively showed that our operations were not responsible for methane migration issues in Susquehanna County.”
DEP is making no recommendations to the residents on whether or not it’s safe to drink their water.