I used to use tap water but am more cautious after springing two leaks in house pipe system. Long story short, very hard water combined with chlorine thins the copper piping causing pinholes or worse. House was built with the thinnest-walled piping per code at the time. Faced with the choice of re-piping, I decided to contract an epoxy-lining service that has, thus far, worked well. But I am concerned microscopic bits might leach into water over time. That the coating is "food grade" is not comforting!
So, I have a series of 5-gallon BPA-free jugs with spouts that are re-filled from a nearby "water store." Used for birds and human consumption! Somebody tell me I'm paranoid!!