Most big cities I would agree with. Out here in the sticks the small town water treatment leaves much to be desired. We have ALOT of lime in our water and various other minerals that contibute to the "hardness" of the water. The National average, so I am told, is 8 parts per million. We have been tested at 32 parts per million. That is extremely hard water but still within the safe drinking limits established by the FDA. Tell that to the guy here who cleaned out his water heater because it quit working and removed a nearly full 5 gallon bucket of lime and other sediment from it. Granted the heater was 10 years old and now works again, but still...yuck.

Yeah we have a high manganese and iron content in our water which when it gets bad turns the water brown/orange in color and has a small stink to it. But with the filters in place its just fine. But still I by 1 gallon jugs at the store to drink just incase.

I know with all those minerals in the water it clogs the faucets and washing machines because of the deposits.

all the crusties that bind up the threads....

All the household water goes through my softner first (with the exception of one outside faucet) and that removes most of the heavy sediment and chlorine. The RO gets rids of anything else left after that includeing the salt that was added in the first stage.