My first proper jobs after leaving college were as a lifeguard. You would be amazed at some of the things people do.
Pee never worried me much, sometimes 'number two's were released though and someone had to get it out cleanly otherwise the pool might have to be drained ...
The first pool I worked in was ozone rather than chlorine, of course I never much thought about it back then but that was a healthy pool in the scheme of things.