I have heard varying degrees on this. some on then left coast say yes, some non the east say no. I think it all depends on the local water table. and all the dechlorinator in the world won't remove heavy metals.

I only use dechlorinator with my frog tanks. my fish tanks just get filled right from the tap. we don't add chloramines to the water supply here. and with as much circulation that I run in my tanks, the chlorine off gases pretty quickly.