Fracking in America generated 280bn US gallons of toxic waste water last year - enough to flood all of Washington DC beneath a 22ft deep toxic lagoon, a new report out on Thursday found.

The report from campaign group Environment America said America's transformation into an energy superpower was exacting growing costs on the environment.

"Our analysis shows that damage from fracking is widespread and occurs on a scale unimagined just a few years ago," the report, Fracking by the Numbers, said.