The two systems work independently of each other within
the same service area. Dual distribution systems are usually used to supply potable water through one
distribution network and non-potable water through the other. The systems would be used to augment
public water supplies by providing untreated, or poorly treated, water for purposes other than drinking.
Such purposes could include fire-fighting, sanitary flushing, street cleaning, or irrigation of ornamental
gardens or lawns.