Water Problems From Drilling Are More Frequent Than Officials Said

When methane began bubbling out of kitchen taps near a gas drilling site in Pennsylvania last winter, a state regulator described the problem as "an anomaly." But at the time he made that statement to ProPublica, that same official was investigating a similar case affecting more than a dozen homes near gas wells halfway across the state.

In fact, methane related to the natural gas industry has contaminated water wells in at least seven Pennsylvania counties since 2004 and is common enough that the state hired a full-time inspector dedicated to the issue in 2006. In one case, methane was detected in water sampled over 15 square miles. In another, a methane leak led to an explosion that killed a couple and their 17-month-old grandson.

Methane is the largest component of natural gas. Since it evaporates out of drinking water, it is not considered toxic, but in the air it can lead to explosions. When methane is found in water supplies, it can also signal that deeply drilled gas wells are linked with drinking water systems.

In many cases the methane seepage comes from thousands of old abandoned gas wells that riddle Pennsylvania's geology, state inspectors say. But other cases, including several this year and the 2004 disaster that left three people dead, were linked to problems with newly drilled, active natural gas wells.

Dimock resident Norma Fiorentino's drinking water well exploded on New Year's morning. The blast was so strong it tossed aside a several-thousand=pound concrete slab. Click to see more of Dimock's residents' stories. (Abrahm Lustgarten/ProPublica)

The issue came to the forefront in January when methane was found in the water at 16 homes in the small town of Dimock, in northeastern Pennsylvania. State officials cited Cabot Oil & Gas for several violations they say allowed the gas to seep out of the well structures and into water supplies there. The Department of Environmental Protection asked the company to encase its lower well pipes completely in concrete -- a process known in the industry as "cementing" -- and assured the public that the contamination in Dimock was rare.

But according to a department spokeswoman, there have been at least 52 separate cases of what the state calls "methane migration" in the past five years. In two of the 2009 cases, regulators responded to complaints from more than 32 households and asked gas companies to supply clean water to at least a dozen homes with contaminated wells.

An undated report from the Pittsburgh Geological Society posted to the DEP's Web site makes it clear that old wells and new drilling can lead to stray gas problems. "Although it rarely makes headlines," the report reads, "damage or threats caused by gas migration is a common problem in Western Pennsylvania."

Craig Lobins, the DEP regional oil and gas manager who initially described the Dimock case as an anomaly in interviews with ProPublica, said he still believes the frequency of contamination incidents is statistically insignificant.

Records show there are roughly 58,000 active gas wells in Pennsylvania. "We are just dealing with a very small percentage," he said in a follow-up interview.

The case Lobins was investigating at the same time as the Dimock case concerned a string of problems in Bradford, a rural town 200 miles west of Dimock along the state's northern border. Shortly after a contractor for Schreiner Oil and Gas drilled several dozen wells in the area last spring, residents began complaining of murky and foul-smelling tap water. When the DEP investigated, it found methane in three water wells and metals in six others. It asked Schreiner to supply water to eight homes, and the company has begun installing water treatment systems at each house. While no new gas wells have been drilled in the Bradford area, according to the DEP, the existing ones continue to operate.