5. San Francisco, CA
Contaminants detected above health guidelines: 3
San Francisco is one of the cities with the cleanest tap water in the US, according to EWG’s data. There are three harmful chemicals that exceed the proposed limits and those are chlorate, radiological contaminants, and trihalomethanes.
![15 Cities with the Cleanest Tap Water in the US in 2017](https://imonkey-blog.imgix.net/blog/wp-content/uploads/2015/10/20184953/shutterstock_76265521-750x500.jpg?auto=fortmat&fit=clip&expires=1756512000&width=480&height=320)
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The following two cities on our list of cities with the cleanest tap water in the US in 2017 share the third place.