Just pump it back into the ocean. The little bit of concentrated brine from a desalination plant will be quickly diluted; the ocean contains a LOT of water.

Particularly if they distribute it over a large area, as they do in practice and shown in the vid.

Bury it deep below the surface. In old salt mines, perhaps.

The products of desalinization aren’t salt and fresh water. They’re somewhat saltier brine and fresh water.

Sounds like it's time for USA to get another Salton Sea