There are likely 200,000 abandoned oil and gas wells in Pennsylvania. At best, we know where about four percent of them are.
This is a problem because abandoned wells provide a pathway for natural gas to seep to the surface, where the methane can pool in water wells, basements or other enclosed spaces, and trigger explosions.
Methane migration can also take place when an active drilling site gets too close to an old well. That’s what happened this summer in Union Township, Tioga County. The result: a 30-foot geyser of methane and water.
StateImpact Pennsylvania explored this problem in a four-part series called Perilous Pathways. Click here to read every article, as well as a map plotting the location of every known abandoned well. Listen to our accompanying broadcast report below: