The groups have asked the U.S. Environmental Protection Agency to investigate and conduct a full audit of the Ohio Department of Natural Resources' regulatory program over the wells, which accept wastewater from oil and gas drilling, and consider taking back control.

A spokesman with the EPA's Chicago office said the agency is reviewing the request.

The call on Monday to diminish Ohio's oversight role was issued by the Ohio office of the Center for Health, Environment & Justice, the liberal ProgressOhio and the Buckeye Forest Council.

They question the effectiveness of Ohio's regulatory program in light of recent federal indictments of a Youngstown-area businessman and his employee that allege they illegally dumped oil and gas wastes, a series of earthquakes near Youngstown centered near a deep well, and what they say is a general lack of public responsiveness.

"We regret that Ohio's administration of the nationwide program has become so gravely lacking that federal controls must be put back in place," their letter to the EPA said. Ohio is among states with authority over its own wells under the national program.

In indictments last month, Hardrock Excavating LLC owner Ben Lupo and employee Michael Guesman were accused of violating the Clean Water Act by illegally dumping oil and gas wastes into a storm drain. The two pleaded not guilty Friday.

Lupo also owns D&L Energy, whose deep injection well was at the epicenter of more than a dozen earthquakes in the Youngstown area mostly in late 2011. An earthquake on the eve of 2012 prompted Gov. John Kasich to issue a temporary moratorium on new injection activity in the vicinity.

After an effective statewide ban of nearly a year, the state resumed issuing injection permits in November. State natural resources officials said they believed ample safeguards had been put in place, including the ability to order or conduct seismic testing before, during and after drilling.

But Teresa Mills, of the Center for Health, Environment and Justice, said the state Natural Resources Department has become "a captured agency."

"It's an agency that's very existence relies on the industry it regulates."

Activists question whether the agency can impartially conduct the investigation ordered by Kasich into whether potentially lax regulations led to the dumping incident alleged by federal prosecutors.

"We don't believe the agency responsible for the lack of enforcement should be conducting an investigation of itself," said Cheryl Johncox, director of the Buckeye Forest Council.

A message seeking comment was left Monday for the spokeswoman for the Natural Resources Department.

The department and Ohio EPA permanently revoked the permits of D&L Energy and Hardrock Excavating after investigators observed employees dumping unknown quantities of a mixture of oil and chemically laced brine into a storm sewer Jan. 31.

ProgressOhio Executive Director Brian Rothenberg said a vigilant regulatory program is imperative because Ohio law does not allow the general public to know exactly what chemicals are being used to fracture shale formations to extract oil, gas and natural gas liquids.

Some of that wastewater is disposed into the deep wells, and some is making its way to Ohio landfills and natural waters.

The Kasich administration's pending budget bill includes proposals for a host of new testing, reporting and tracking requirements involving contaminated solid wastes from drilling.

Planned changes would require drilling companies to test drilling muds, dirt and rock for radioactivity that hasn't occurred naturally and to share that information with landfills before the waste is accepted. The legislation also sets thresholds for what concentrations of technologically enhanced radioactive material that could be disposed.