The pool industry is fighting this action by Santa Clarita, Ca. Unfortunately LA was trying to follow with them. However, there is no basis for this conclusion as salt from a salt pool is minimal in comparison to the other sources of "sodium" being leached into the water system.
It's not the salt being used in Salt Chlorine generator pools, it's the discharge from backwashing that they are concerned with.
At this time, Santa Clarita is the only city that is preventing builders from installing salt chlorine generators on pool. Also banned are water softeners!