Salinity like, ocean bed salt/saltwater inclusion into wells/ road salt runoff, is rarely a problem for growers except in very specific areas.

However, 'salts' are not just Sodium chloride, Calcium chloride, or Calcium-Magnesium Acetate (all common road deicers that you will have to contend with if you grow near a highway that gets salted).

Salt buildup can be a problem in pots in as little as a few weeks if you are:

-Feeding aggressively
-Using pre-ferted soil
-Your tap water has an unusually high mineral content
-Using shitty fertilizer that does not contain adequate chelating agents
-Any combination of the above

Just one more reason to use good quality fertilizer! And flush at the first sign of combo burn/def = LOCK OUT!!!