12. What are the advantages and disadvantages of the Point of Use (POU) System?

POU advantages:

  • When POU is used for a single tap, Installation cost is less for POU than for POE.
  • When POU is used for a single tap, maintenance cost is less for POU than for POE.

POU disadvantages:

  • Water from untreated taps still contains unhealthy levels of arsenic. 
  • Once the under the sink storage reservoir is depleted the flow volume will be down to a trickle until the storage reservoir fills back up with treated water, and this may take a couple of hours.
  • Some POU systems only remove Arsenic 5 (reverse osmosis).
  • POU systems usually do not have a safety tank so users will be exposed to arsenic contamination after the capacity is reached and before testing indicates the need for a replacement.
  • With a POU systen you will still be bathing, showering, brushing teeth, washing clothes and filling up swimming pools or hot tubs with arsenic-contaminated water.
  • Studies have shown that in homes with a single tap arsenic POU water treatment system, it is not uncommin for people to occasionally drink from untreated taps, and when they do, arsenic levels increase in their urine.                                                                                                                                                                                                                               http://www.sciencedirect.com/science/article/pii/S00489697_1400881X                                                                         http://www.sciencedirect.com/science/article/pii/S00489697_15311190
  • 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