Correct, under permit by state agencies. In that case, the correct term is discharging, not dumping. Just like when you take a dump at home or at work.<quoted text>.. which currently involves dumping into municipal systems.
Fracking water contains high concentrations of chlorides and total dissolved solids, which are not toxic except for the high concentrations. Discharging in small quantities to municipal systems lowers the concentrations and minimizes environmental effects. This is a short-term approach until treatment facilities, essentially a form of desalination plant, are constructed.