The fracking boom happened so quickly that nobody had any time to deal with the consequences. Not only did politicians not anticipate regulations, allowing the industry to operate in a kind of free-fire zone, but the industry didn’t recognize the massive amounts of limited resources they would need to continue fracking in the future. Specifically, they didn’t estimate the water needs.
Fracking requires enormous amounts of water. To frack 35,000 wells for one year, you need roughly 70 billion to 140 billion gallons of water, the amount used by all the citizens of any of the largest cities in America, like Chicago. There’s a limit to how much water will be available over time without just wresting it away from drinking supplies and other human needs, short of draining the oceans (hey, there’s one way to combat sea level rise, just skim it all for fracking!). And a lot of fracking takes place in remote areas without access to that much water without trucking it in. So it has just dawned on the industry that they might want to try to recycle their wastewater.