Shipboard potable water (drinking, bathing, whirlpools, etc.) either comes from a shoreside water treatment plant or is generated on board from seawater via Reverse Osmosis systems or Evaporators. Swimming pool water is typically seawater.
Our potable water is regulated by the Centers for Disease Control U.S Public Health Service Vessel Sanitation Program (CDC-USPH-VSP). Among various other requirements, the water on board is halogenated to USPH standards, regardless of where/how the water is obtained.
Additional requirements must be followed to maintain whirlpool and swimming pool sanitation. As per USPH, Chlorine levels need to be between 3-10mg. The water is drained out and loaded a few times during the cruise but it may depend on restrictions the ship is subject to as far where and when they can discharge water into the sea. It cannot be done in the home ports so it is typically done before arrival, if the itinerary permits. .
USPH inspects each of our vessels twice per year to ensure compliance with these standards as well as other USPH requirements. These inspections are publically available on the CDC’s website.