Flushing toilets with drilled corrosive non potable water

We have an adjacent property (with the same owner) that has to remove non potable water from its foundation. This groundwater flows in a large part from our property. We would like to drill and take this water from our site to use for flushing toilets. A geolocist says that this is the same water that has to be removed in the adjacent property and this decreases the amount needed to be removed. We see this drilling as a method of removing foundation water that is not potable. Is there any chance this will get approved? Would it be better if we pumped the water directely from the foundation in the adjacent property? Thanks in advance, Viktor