"The flooded wells are evidence that brine is 'migrating' underground through crooks and crannies in the rock... Complicating matters, as many as 66,000 undocumented, old-fashioned oil and gas wells pockmark Ohio, according to state estimates."
In Ohio, Toxic Wastewater Is Bubbling Up Out of the Ground
The state is a major importer of fracking wastewater, which gets pumped underground but doesn’t always stay there. The city of Marietta is fighting back.
nytimes.com