The gas drilling industry says fracking hasn't been linked to water contamination. But it has.

"Mike and Nancy Leighton's problems began on May 19, just as Mike was settling in to watch the Preakness Stakes. A neighbor in Leroy Township, Pa., called Mike and told him to check the water well located just outside his front door.

'And I said I'll be down in 15 minutes. I wanted to see the race,' Leighton said. But as the horses were racing, Leighton's well was overflowing. Typically, there's between 80 to 100 feet of headspace between the top of the well and its water supply. But when Leighton went outside, the water was bubbling over the top.

Down the road, Ted and Gale Franklin's water well had gone dry. When water started coming out later that week, the liquid was 'black as coal,' according to Gale."

Scott Detrow reports for NPR's Morning Edition August 28, 2012. [2]