I live in America (Minnesota), and tap water has always been safe to drink in my lifetime. There are other places in the US where it’s discovered that the tap water has been unsafe, but that’s generally seen as a huge scandal and a public health emergency, and culprits are tracked down.
It’s my impression that people nowadays drink a lot of filtered water, either through a water tap on their refrigerator that has built-in filtration, or through a pitcher with a built-in filter. I believe people mostly do this for flavor reasons, or out of an abundance of caution rather than any real, concrete concern over the safety of the tap water.
In Minneapolis, every spring there’s typically an algae bloom that makes the tap water taste like vegetation for a few weeks, and that’s gross, but I believe it’s safe. That’s the worst tap water experience I’ve had. When I was a kid, I remember being told that the tap water up at the family cabin was so hard (rich with minerals) that it could make someone constipated, but that sounds like nonsense to me now.
Interestingly, there are places in the US where there’s more lithium in the water than in other places, and studies have been done that show that people in those areas are a little happier (less incidence of self harm, crime, etc.)! So sometimes, the tap water is even beneficial 😜
I’m still looking for a true crime / unresolved mysteries community.