See, the problem is, no one has had issues with widespread systemic impacts.
They have issues with an ALARMINGLY high number of local impacts. Also, I wonder if this is just evaulating the actual fracturing process itself, or if it is including things such as companies dumping produced water 100 feet from a stream (It's happened multiple times - they're not allowed to do it, but underpaid truck drivers take shortcuts.)
Also, part of the reason we haven't had widespread impacts is because people who live in areas with large surface drinking water supplies (as opposed to primary drinking water being underground aquifers) have been fighting hard - New York City has one of the largest untreated water supplies in the world, and it is fed by a network of reservoirs and streams upstate. NYS has been good about keeping fracking AWAY from this infrastructure.
It's just a matter of time before those local impacts become systemic if fracking is allowed in more areas.