What are the best water treatment plants in the world?

I took a different route and searched for the best tasting water which is IMO the Hallmark of efficient state of the art water treatment protocols.

Berkeleysprings drinking water taste contest. and
Top 10 Countries With the Best Tap Water

@Cruiser The best treatment plants, as in the ones that would make it impossible for raw sewage to somehow end up in the river etc.
I wish I had that in the detail part.

Sorry you asked water treatment plants not sewage treatment plants pretty big difference yet there is now technology to do both.

OMG! Thanks for the correction.

Water Lillies?

Thanks @Cruiser for the link.