Some people depend on their own well, pond, spring or cistern for drinking water.
Individual water supplies of this sort are private. Water testing or water treatment is usually not required by law. Dairy water supplies must be tested for bacteria and meet dairy industry standards. Water testing and treatment can be expensive and time-consuming, but they are the only ways a homeowner can ensure a safe and reliable water supply. Individuals using public water supplies pay for water testing and treatment as a part of their water bill.