I got thinking about this question after some recent flooding and we were supposed to boil drinking water. Chloramine isn't at high enough levels to kill some contaminants that might get into the pipes, I guess.
When I worked in a lab, there was a DI water supply for the whole building, and they also UV sterilized that water. Like I said, maybe just paranoia to even think about this... Though it would beat having to boil water every now and again.