GRANGER TWP., Ohio -- Mark Mangan held a metering device near his backyard well and listened to an alarm go off.
It registered one hundred percent "LEL," or lower explosive level.
"That means, if we light a match right now," Mangan said, "it'll go boom."
Mark and his wife, Sandy, have no idea how big or small such a possible explosion may be.
But they blame the drilling of two nearby oil and gas wells a few years ago.
"It's a beautiful spot," Mark said of his rural home, "but now, I just want to get the hell out of there."
The two wells in question have since been "fracked" - that is, highly-pressurized chemicals have been injected into the ground to help with the recovery process.
But the Mangans blame the initial drilling for their problems, and say they quickly contacted the Ohio Department of Natural Resources (ODNR) about the issue.
"We thought they were going to be an advocate for the people," Sandy Mangan said.
ODNR declined to do an on-camera interview, but said in a statement that it had conducted "extensive testing" and has "conclusively determined" that the Mangans' water problems are "not related to those (oil and gas) wells."
Sources tell the Fox 8 I-Team that the Ohio Inspector General is looking into the issue.
Officially, Deputy Inspector General Carl Enslen said the office will neither confirm nor deny the existence of any inquiry.
In a report, ODNR indicated that a "drought" may have been a factor.
But a Cleveland State University expert, Dr. Philip DeGroot, said a drought would not cause the sudden drop in water pressure that the Mangans reported that they experienced.
Dr. DeGroot, who was hired by the Mangans and one other family to do a preliminary analysis, said such a drop is normally caused by a more traumatic event such as an earthquake.
"You could cause fracturing where fractures didn't exist, so something like (an earthquake), something that would be a high-pressure underground activity."
The Mangans said it wasn't an earthquake, but oil drilling that caused the problem.
But, in a report, ODNR said it found no evidence of the chemicals used in oil drilling in the drinking well at the Mangans' home.
And the operator of the oil and gas wells said the Mangans were having water issues before the drilling began.
The Mangans vehemently deny that, and say they don't know what the future holds.
"We have no idea what we've been exposed to," Mark said.
And they have no idea how much danger may be still lurking in their well.