NYT article uncovers unsanitary water towers in NYC. No kidding.
The city with the best water in the US gets it from Catskill and Appalachian mountain lakes, right up to the curb of NYC buildings. Then it is pumped up to iconic water towers, where regulation is lax and enforcement nil. So no surprise when NYT reporters find some tanks not fit to store water. But solutions abound: build sealed tanks, write and enforce regulations, clean tanks regularly, and use water management tools, like water-aeration, to keep the precious water pristine.