There are lots and lots of places around the US where the ground water contains natural and artificial chemicals at unsafe levels.
The artificial chemicals may be somewhat easier to deal with, as they usually have a single point of origin, forming a bloom that travels outward from that point.
A way to deal with this problem might be with a “standard” nuclear water purification system.
Several companies are actively building small, self contained nuclear reactors that need minimal maintenance but produce large amounts of electricity for a given number of years. Some models are about the size of a large steel shipping container.
To start with, a large well is dug as close as possible to the point of contamination origin. Water containing the contaminant will be pumped up from this site, then put through a distillation process for nonvolatile contaminants or reverse osmosis for volatile contaminants.
But then, the distilled water will be pumped back underground in numerous smaller wells, with outlets at different depths, at the perimeter of the bloom. Thus the center of the bloom will have negative water flow, and the perimeter positive water flow.
That is, the perimeter water flow will uptake contaminants and transport them to the center to be pumped out.
Because the contamination in the center is much greater than at the perimeter, doing it this way will be the fastest means of reducing the levels of contamination to acceptable levels.
Importantly, since until the ground wells in the area cannot be used for potable water until the contamination is reduced, the perimeter wells might have additional, but harmless, chemicals added to the water, like activated charcoal, that will speed up the decontamination process by helping to absorb or neutralize contaminants that are to be pumped out.