Chemical Degradation of Plumbing
https://louisville.edu/speed/civil/cir/files/elastomer-degradation.html
In summary, there is no code requirement that the quality of the water be verified. There are federal laws in place, but enforcement is anything but reliable across the country. I would recommend a custom filtration system with CLEAR filter housings that allow the user to visually inspect the cleanliness of their water, so that we can be more aware of the substances we put in our bodies.