Chlorine, fluoride, bromide, all the crap inside the pipes that leeches-- PVC, CPVC, PEX, all of those plastics, in some cases like in Flint, Michigan you can get lead. But that was because of bad engineers in the city. Old pipe with lead can be safe because smart munincipal engineers will keep the water supply slightly alkaline, which puts a scale layer of calcium on the inside of the pipes, creating a barrier. In Flint they changed the water source and started to use water from the lake, which was slightly acidic. The layer of scale dissolved and lead began to leech into the general water supply.
Water from a well or a spring is best, followed by rain water (but it needs to have a bit of mineral content added, otherwise your bones can begin to lose calcium), then reverse osmosis.
Water bottles can be bad too though, especially if they've spent much time in the sun. The plastic gets into the water eventually, and plastic is bad for you, it simulates estrogen in the body.
Media Justin Gaethje Opens Up About Max Holloway Fight at UFC 300 (With Cliffs).
