The natural gas industry is pointing to a Penn State University study to boost its mantra that gas drilling is not linked to pollution of water wells.
But a drilling critic says the study found increased levels of a harmful chemical in water wells after gas drilling occurred nearby. He thinks other aspects of the study overlooked potential well water contamination.
“The Impact of Marcellus Gas Drilling on Rural Drinking Water Supplies” was authored by Penn State water quality experts led by Elizabeth Boyer, associate professor of water resources, director of the Pennsylvania Water Resources Research Center and assistant director of the Penn State Institutes of Energy & Environment.
The research was sponsored by a grant from the Center for Rural Pennsylvania, a bipartisan legislative agency within the state General Assembly. The goal was a large-scale study of water quality in private water wells in rural Pennsylvania before and after nearby Marcellus Shale drilling.
For the study, the researchers evaluated water sampled from 233 water wells near gas wells in 2010 and 2011. The first phase focused on 48 private water wells located within 2,500 feet of a nearby shale well pad. The second phase focused on 185 private water wells located within 5,000 feet of a shale well pad.
During the first phase, researchers collected pre- and post-drilling water well samples and analyzed them for water quality. In the second phase, researchers or homeowners collected only post-drilling water well samples and analyzed them for water quality. The post-drilling analyses were compared with existing pre-drilling test records.
John Krohn, spokesman for Energy In Depth Northeast Marcellus Initiative, noted excerpts from the report that said analysis of the water tests “did not suggest major influences from gas well drilling (or hydraulic fracturing) on nearby water wells.”
Hydraulic fracturing, or fracking, is the high-pressure injection of millions of gallons of water, sand and chemical additives deep underground to extract natural gas trapped in shale rock.
The study also found no clear link between methane migration and natural gas production, Krohn said.
Methane is a gas that some residents living near gas wells have lit on fire as it escaped from their kitchen faucets along with their well water.
Krohn also noted 40 percent of the water wells tested failed at least one safe drinking water standard, mostly for coliform bacteria, turbidity and manganese, before drilling occurred. This shows a need for uniform water well construction standards that don’t exist in Pennsylvania, as well as a need for education of water well owners.
Dr. Tom Jiunta, founder of the local Gas Drilling Awareness Coalition, said study findings of increased levels of bromide and sediment/metal levels in wells after drilling/fracking were of particular concern to him.
“This finding alone shows that many wells near drilling sites are impacted by migration of underwater brines and possible drilling muds, both hazardous to drinking water supplies,” he said.
Bromide itself is not a health threat, but elevated levels “can create an indirect health issue as it may combine with other elements in water to cause carcinogenic compounds,” the report states.
Jiunta said nearly 80 percent of the water wells were not pre-tested for methane, bromide or oil/grease because well owners couldn’t afford the expensive tests. “This skews the data,” he said.
Jiunta also said the study considers only short-term changes in well water after nearby gas wells were drilled – less than three-month time periods. He said that time period is “inadequate for determining contamination,” citing a Temple University engineering professor who said most problems with underground water contamination would most likely take several years to be detected.
The Penn State study was released as the U.S. Environmental Protection Agency begins a federal probe into whether hydraulic fracturing is spoiling and diminishing drinking water supplies.
The agency’s final study plan was released Thursday. The first results will be available in 2012.
To read the study, visit www.times