I don't know if this is a concern for you or not but one of the reason new wells need to be run for so long before the are hooked up is the massive quantiy of chlorine or bleach that is placed in a new well to sanitize it from the drilling. This water is not fit to drink and would hinder microbes. I beleive the sunlight would neutralize this but I wouldn't run it into my pond if I had any creatures I cared about in there.