“I’ve always heard that New York’s water source is superior to most municipalities, coming from the Adirondack snow melt.”
NYC water comes mostly (90%) from the Catskill Mountains snow melt and rain. The remainder comes from the first three counties north of NYC on the east side of the Hudson River. No water comes from the Adirondack region.
Here’s a map of the system: https://www.nyc.gov/assets/dep/downloads/pdf/water/drinking-water/water-supply/nyc-water-supply-system.pdf
Regardless, historically the water is described as very pure and of the perfect mineral content.