Is it ok to drink water onboard? Key items for consideration
- Water supply system: it includes operating procedures; water intake, facilities for water production, water treatment plants, tanks, main tap point.
- Internal distribution network: It includes all water pipes and conduits in the ship, heaters, tanks, taps.
- Hygienic barriers: water taken out on the ocean as well as technical measures to remove, neutralize or kill bacteria, viruses, parasites, etc.., and / or diluting, decompose or removing chemical or physical agents to a level where the substances no longer represent any health risk.
- Operational analysis of drinking water: Internal analysis of the drinking water as part of internal control and adjustment of the operation of the drinking water facility, including the analysis taken in connection with the bunkering of potable water.
- Routine Analysis: Routine analysis of water samples sent to an accredited laboratory on land, and used to document that the operation of drinking water facility has been satisfactory, and possibly as a basis for assessing changes in operations.
How to control quality of potable water
Control procedures shall always be based on a risk assessment. Ships either produce drinking water from seawater using evaporation or reverse osmosis or they refill (bunkering) fresh water from land. In other cases, drinking water is purchased bottled and distributed to seafarers. Depending on whether its production takes part on board or is purchased from a water supply system on land, different levels of control are necessary to check water quality.
x When producing water on board, there must be continuous control of the production line and periodic control of the internal distribution network. As a minimum, the water shall be disinfected.
x When purchasing fresh water from land it is generally required only periodic control of the internal distribution network. If the water is purchased bottled, the conformance of provider with quality standards and the checking of expiration dates are key control measures.
Best practice requires that water shall be analyzed prior supplied to the seafarer through sampling. Also, Flag administration guidance should be taken into consideration regarding periodic analysis of drinking water. In essence, sampling requires taking samples from taps and this applies to any water tap in the ship. Since there are many taps in a ship, a risk analysis is vital to address key taps because, if there are many points it may not be necessary to sample all of them every time, but rather add up to a rolling sampling regime.
Examples of key sampling points and / or control points can be:
- Seawater before the water treatment
- Filters used to filtering the intake water
- The water treatment processes
- Water from drinking water tanks
- Taps in the galley
- Points elsewhere on the pipelines, especially near the end of a pipeline.
If bunkering freshwater is conducted from a supplier where there is uncertainty with regards to the water quality, sampling of the water should be done before bunkering. Samples taken in connection with the production of water on board or while bunkering are part of the operational analysis. Furthermore, labeling on board is vital in order crew and passengers to be informed from which resources the water is drinkable or not. Hoses and piping system should also be labeled for potable water and procedures for testing to be implemented properly.