The Biden administration is proposing a ban on TCE, a highly toxic chemical commonly used in stain removers, adhesives and degreasers, and which had been found to be contaminating drinking water on a wide scale across the US.
Because the pollutors responsible for those chemicals have purchased the "conservative protection plan". They pay conservatives to allow them to continue to pollute. Part of that protection plan is classifying their deadly pollutants as "safe for consumption" to limit civil liabilities.
Its probably crazy expensive to do that. Also, my guess is the processes of removing anything not H2O and minerals would also remove the minerals. So you'd have to do full distillation removing everything, then source and add in minerals after the distillation. The energy needed would be immense.
Assuming you're serious; It would be nearly financially impossible to do this just from the sheer amount of water we're talking about. Have you seen how big the lakes are in person? I've only been on lake Huron, but you can get to a point where the horizon is just water. These lakes can also have deadly storms, since they are massive bodies of water. You would need the find a power source that would have to nearly be infinite. You would need a cooling system that suits it. You would need a LOT of maintenance. You'd spend a lot on materials, too. That's all assuming that it would even work. That money would have to come from somewhere, and it would probably be one of if not the most expensive machines to exist. The scale of the filter would have to be miniscule to catch those chemicals.
We just don't have the capacity for that yet. We would have to split things on such a small scale that it wouldn't be a reasonable solution. It would be as difficult as trying to find a grain of sugar in a pound of sand.
We would have done this if we were at that point, at least somewhere. Who wouldn't want credit for solving the world's water problems? A filter of that size would make sea water drinkable. It would have to be on a molecular scale.
How about the polluters pay for it instead through the massive profits they've managed over years of ignoring the potential issues ... the same as how big oil should pay to clean up its own dormant wells, pipelines and infrastructure.