Marcellus shale well accident reinforces need to guard water quality

June 21, 2010

University Park, Pa. -- The recent eruption of a Marcellus shale gas well in Clearfield County, Pa., has triggered investigations by state agencies. A Penn State Cooperative Extension water specialist said it also should remind Pennsylvanians that drilling can impact surrounding water resources, and well owners near any drill sites should take steps to monitor their drinking water.

The contaminated water spewed by the natural-gas well for more than 15 hours may have entered a local aquifer. Bryan Swistock, senior extension associate in the School of Forest Resources, said the state Department of Environmental Protection will probably check local streams for contamination, but it may be prudent for water-well owners living near the spill to have an independent laboratory test their well water. He said the tests for various contaminants have a range of costs and implications.

"Things like methane, chloride, total dissolved solids and barium are very good indicators and are relatively inexpensive to test for -- most labs can do them," Swistock explained. "When you move down into the organic chemicals that might be used in fracturing, the cost to test for them goes way up. The risk is much less for those, typically, so it's not quite as important, but again, if you can afford to do that testing, that's great."

The Department of Environmental Protection ordered a contractor hired by the gas-well owner to stop some of its work in the state, hand over equipment records and provide access to employees as DEP investigates the equipment used by the company.

"They haven't determined how the blow-out happened, but it appears that it allowed a lot of gas and hydrofracturing fluid to escape on the ground into nearby streams," Swistock said. "That reinforces how important it is for people who live near natural-gas drilling to document their water quality before the drilling, so that if any incidents do occur, you can prove they happened. And that includes testing of wells, streams, ponds and any water resources that you're concerned about before the drilling occurs.

"It's hard to document anything if you don't have any pre-existing data," he added. "It's important that homeowners have an unbiased expert from a state-certified lab conduct the tests, in case the sample results are needed for legal action."

Water forced into subterranean pockets as part of the drilling process dissolves many chemicals out of the rock, Swistock said, and may gather large amounts of iron, calcium, magnesium, strontium and barium, and small amounts of arsenic and lead. There also are enormous amounts of sodium and chloride as water dissolves chemicals left behind by ancient sea water.

Swistock said balancing frequency of testing with the proximity of the drilling activity is an individual decision for each well owner.

"Fracking is a very intensive industrial activity, and these kinds of incidents are going to happen," he said. "They don't happen very often if we look at the history of the industry, but people have to decide on their own how concerned they are and how much testing they want to go through. Certainly, water supplies within 1,000 feet of the drilling are considered at higher risk. Beyond that, it's up to the homeowner to decide. If some people 5,000 feet away are concerned and want to get testing done, that's really their choice."

About 3.5 million Pennsylvanians get their water from private wells and springs, according to Swistock. He said residents who want more information on Marcellus shale gas exploration can find it online at Penn State Cooperative Extension's Natural Gas website at

(Media Contacts)

Last Updated January 16, 2012