Sounds like you are a well-informed, inquisitive person seeking real answers to difficult questions. I applaud you.
Personally, I believe my drinking water in TN has fungal spores in it. I have actually retrieved a filamentous fungus from the water which seems to move toward a food source (drain maid from biosmart.} The water company admits there is "algae" in the water, but I believe it is disease-carrying fungus and they either don't know or they are lying.
The EPA closed 2 inquiries I sent them without replying to my concerns. I guess they wrote me off as a crazy. Or, could it be Conspiracy ....