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:
More than 470 people are suing BP for $1 billion, saying they became sick due to a 15-day gas leak at its refinery in Texas City.
The Galveston County Daily News reports that BP says mercaptan leaked from a storage tank in November 2011.
Mercaptan is a pungent, harmless gas often added to natural gas so that the odorless, flammable substance can be more easily detected.
Attorney Anthony Buzbee says the leak also contained sulfur dioxide, a toxic gas.
BP has declined to comment. The refinery has since been sold to Marathon Petroleum.
In 2005, 15 people were killed in an explosion at the same refinery. More than 50,000 people have sued BP saying they were sickened by another leak at the refinery in 2010.