Danger in honeycomb of 12 million old abandoned gas wells

[Divernan]

Very detailed article about abandoned and forgotten wells going back 150 years.

Danger in honeycomb of old wells
Yesteryear's energy prospectors left a legacy to be reckoned with
Monday, April 04, 2011
By Nicholas Kusnetz, ProPublica


Government reports have warned for decades that abandoned wells can provide pathways for oil, gas or brine-laden water to contaminate groundwater supplies or to travel up to the surface.

New wells sometimes disturb layers of rock and dirt near fragile old wells, leading to new cases of contamination. For Pennsylvania and other states sitting on top of the Marcellus Shale formation, the rapid growth of gas drilling may increase the danger of such contamination.

In 2008, gas from an abandoned well leaked into a septic system in Pennsylvania and exploded when someone tried to light a candle in a bathroom, killing the person, according to a 2009 draft report by the state Department of Environmental Protection. That report also documented at least two dozen other cases of gas seeping from old wells, including three where the drilling of new wells "communicated" with old wells, leaking gas into water supplies and forcing the evacuation of a home.

In February, methane from an old well made its way into the basement of a house in West Mifflin, triggering a small explosion. Two families were evacuated and have not yet returned. Such incidents rarely receive much attention outside the states and neighborhoods they affect. But as the nation's latest drilling boom continues, abandoned wells have begun attracting more attention, particularly in states where the earth is already pock-marked with holes left by earlier waves of extraction.



Read more: http://www.post-gazette.com/pg/11094/1136832-84.stm#ixzz1IYHW3FGD