Total dissolved solids must be under 500mg/L in US drinking water supplies, and the highly regarded NYC water system delivers water with less than 50mg/L of total dissolved solids. Most of that is sodium chloride, calcium chloride and magnesium sulfate, classic tasty salts... all of which are readily available in foods.

See http://www.nyc.gov/html/dep/pdf/wsstate13.pdf for the 2013 water quality report; see table 1.

If you got distilled water instead, you'd notice the taste, but there wouldn't be a health problem.