Legal does not necessarily mean safe. Getting a passing grade from the federal government does not mean the water meets the latest health guidelines. (Don’t get me started on the feds.)
Legal limits for contaminants in tap water have not been updated in almost 20 years. (20 years????)
The best way to ensure clean tap water is to keep pollution out of source water in the first place.
The only one thing that separates achievers from non-achievers is that they enlist the help of others to make progress.