which is worse drinking water with nitrates, drinking water with high sodium or drinking water with a low pH?

My body isn't helped by high sodium

in what presently is glacier melt water.

Stop salting slugs you find atop that ice.

It depends on how low that pH is (if you ingest a strong acid you are in big trouble). The human body can tolerate slightly acidic solutions and in some ways they are even good for you but not anything too concentrated.

Salt (aka sodium) is not nearly as bad as people have been led to believe (it's being overweight that puts one at risk of heart disease not necessarily salt).

Nitrates aren't all that good for you (so compared to something only slightly acidic then I would say nitrates are the worst).