It requires "barrels-per-minute for hours" amounts of water. 100 BPM is unusually high for fracking. One acre-foot is about 7753 barrels. The problem is that

It requires "barrels-per-minute for hours" amounts of water. 100 BPM is unusually high for fracking. One acre-foot is about 7753 barrels. The problem is that water is increasingly scarce in many parts where fracking is done for reasons outlined in the book "Cadillac Desert".