There's a mineral hot spring resort I sometimes visit where the water is definitely salty, and has plenty of other minerals influencing the taste. It's the only water source there so all other water has to be brought in. It's drinkable, but coffee just takes on this really distinctive quality ... the local critters don't seem to have an issue with it. The frogs seem to thrive and there are tons of mammals of all sizes...

I've also packed in to hot springs down in Sespe that have plenty of minerals - some of them drinkable, some poisonous. Got to know which are which.