There is Standard Level, which is Municipally Supplied Water, and “Optimal” Level, which is what we called: In-Home Water Systems.

Standard Level:

Municipally Supplied Water is not necessarily optimal quality. More than 85% of us get our water from a municipal water treatment plant. Water is treated to a basic potable standard and distributed to your home through miles of underground pipes. Disinfection agents such of chlorine or chloramines are commonly used to get the water safely to your tap. Since only 1% of water is used for drinking, it is cost prohibitive to treat water to optimal drinking water standards. Additionally, since removing hardness is costly and not a safety issue, few municipalities remove hardness, leaving it up to the homeowner.