I guess it's just the places in the US I've lived in that have safe tap water.

Yes, just the vast majority of the US (geographically and population wise) has incredibly good tap water, with a long tail of famously bad exceptions to the rule.

63 million people is a really, really long tail.

How does this compare to the EU? It's one thing for tap water to not be perfect, it's quite another for it to be as bad as Flint, MI. What's the true distribution here?

Making people unreasonably afraid of tap water just seems irresponsible.

Making people affraid of tap water is the business model of bottled water. US tap water is well known to be bad compared to the rest of the developed world (thanks to marketing).

Where did you get 63 million?

The third link from GP has a headline which reads “360,000 Californians have unsafe drinking water. Are you one of them?”

That’s approximately 1% of CA’s population. That’s not even a long tail.

The second link.

> As many as 63 million people — nearly a fifth of the United States — from rural central California to the boroughs of New York City, were exposed to potentially unsafe water more than once during the past decade, according to a News21 investigation of 680,000 water quality and monitoring violations from the Environmental Protection Agency.

So I believe what’s happening here is that they took the total population coverage of any water district that ever had at least two reports of a water quality or monitoring violation in the last decade.

I think ”potentially” is the key word here which makes this claim particularly washy. Are they looking at violations which actually resulted in measurably unsafe water, which were likely to cause or result in unsafe water, or merely violations which could possibly resulted in unsafe water, or perhaps monitoring lapses which would have failed to detect potentially unsafe water, but without any evidence that water was actually ever unsafe?

It’s a newsroom investigative report, not a scientific study. Take this with a huge grain of salt.

Geographically the vast majority of the US doesn't have tap water.