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.
A bill to more tightly regulate the drilling process called hydraulic fracturing passed the California Senate Natural Resources and Water Committee on a 6-2 vote Tuesday.
California is in the beginning stages of regulating fracking.
Skeptics argue that fracking could endanger public health by contaminating water public water supplies. Sen. Fran Pavley, D-Agoura Hills, the author of Senate Bill 4, called the bill a needed mechanism for holding the energy industry accountable.
"We need to at the minimum ensure that someone, some public agency, is monitoring the public health and safety of Californians," Pavley said.
The legislation would require the energy industry to disclose more information about the amount of water and types of chemicals it uses. It would also set up a permitting process, create a framework for tracking waste water and dictate that communities are notified 30 days in advance of a new well being constructed.
Energy industry advocates called the bill unnecessary.