Sadly no, there is no way, short of reverse osmosis to remove sodium. I checked with some water gurus and the sodium is completely in solution and filters don't affect it.
Gypsum helps neutralize salts but not enough for a lot of plants. We can run our house on the well water. Livestock does fine.
Reverse osmosis is impractical for our situation. So by golly, if I'm going to have the joy of a homegrown tomato I'll haul water!
Thanks for the thought though
Let's see, construct a solar furnace to distill the water, leaving the salts, deicer for the sidewalks and distilled water for the EBs.