I didn't have time to read this whole thread. I use a regular garden hose to fill my fresh water tank. I never hook the the water supply at the parks. (personal preference on my part) I also only sanitize my tank once a year in the spring.
I'm and 53 and not dead yet. There are so many other things that can kill me (like just breathing the polluted air,) that I don't worry about things like garden hoses. I live in a house that was built in 1942. I wonder how many chemicals are in this old place. lol