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.
From the Associated Press:
Pennsylvania plans a major study of radiation levels in oil and gas industry wastewater and byproducts.
The Department of Environmental Protection said in a release Thursday that Gov. Tom Corbett ordered the study.
The agency said the study will look at the levels of naturally occurring radioactivity in underground water that comes back to the surface after drilling, as well as radiation levels during the transportation, storage and disposal of drilling wastes.
The agency said some radiation monitors at landfills have been triggered by drilling waste, but that so far information shows very low levels of natural radioactivity. The new study is expected to take 12 to 14 months.