Making people unreasonably afraid of tap water just seems irresponsible.
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.
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.