If POU treatment at the kitchen sink is used, the kitchen tap should be the only source of water used for drinking or cooking. If water may be used for drinking in other rooms of the home (e.g. at a bathroom sink), either a POU unit should be installed at each potential drinking water tap in the home or a Whole-House Point-of-Entry (POE) system should be used.
When the cost of multiple POU systems is considered, it often becomes more economical to install a Whole-House POE system.
Some local health departments require Whole-House POE arsenic water treatment to ensure the health of current and future homeowners