Chesapeake Energy Corp,the Oklahoma-based firm is the No. 1 driller in Ohio.
Rig Count Interactive Map by Baker Hughes, an energy services company.
Shale Sheet Fracking, a Youngstown Vindicator blog.
The Ohio Environmental Council, a statewide eco-group based in Columbus.
Earthjustice, a national eco-group.
People's Oil and Gas Collaborative-Ohio, a grass-roots group in Northeast Ohio.
Concerned Citizens of Medina County, a grass-roots group.
No Frack Ohio, a Columbus-based grass-roots group.
Fracking: Gas Drilling's Environmental Threat by ProPublica, an online journalism site.
Pipeline, blog from Pittsburgh Post-Gazette on Marcellus shale drilling.
Allegheny Front, environmental public radio for Western Pennsylvania.
The Pittsburgh Post-Gazette reports that methane gas has bubbled to the surface in three residential wells and two streams in Pennsylvania's Bradford Counjty.
The problem surfaced late last weekabout a half mile from two Marcellus shale wels drilled by Chesapeake Energy Corp..
The state Department of Environmental Protection and Chesapeake have been investigating the problem that surfaced in the water wells, two tributariues of Towanda Creek and a wetland in Leroy Township.
Samples were taken at the Chesapeake wells to run isotopic gas fingerprinting tests, officials said.
Alternate water has been provided to the residents.