The document provides guidance for ensuring clean drinking water on small ships. It defines drinking water and outlines requirements for regular water quality analyses at least once per year or more frequently depending on the water source. It lists threshold values that must be met for various contaminants. The guidance also includes steps to prevent contamination and monitor water quality through inspection of the drinking water system, treatment, operations, and actions to take if water becomes contaminated.

1. CHAPTER?
DRINKING WATER – ON BOARD SHIPS
SHORT VERSION
DRINKING WATER – ON BOARD SHIPS
Summary for small ships
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2. DRINKING WATER – ON BOARD SHIPS
CLEAN DRINKING WATER
DRINKING WATER
– ON BOARD SHIPS
Summary for small ships
This is a summary of the ”Drinking Water - On
Board Ships” guidance. You can learn more and
look for more background in the actual guidance at:
http://www.seahealth.dk/sites/default/files/DRIKKEVAND_UK_0.pdf.
The guidance has been issued because there have
been changes to Danish legislation on the basis of
ILO – MLC 2006:
”It shall be ensured that drinking water
on board (for human consumption) is of
satisfactory quality and suitable for the
purpose. It should be able to document
this using regular analyses benchmarked
against international standards.”
Danish Maritime Authority Notices B
of 7/6-2013 Ch.II-3 Rule 20.2
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Drinking water is defined as:
All water either in its original state or after
treatment, intended for drinking, cooking,
food preparation or other domestic
purposes, regardless of its origin and
whether it is supplied from a distribution
network, from a tanker, or in bottles or
containers.
Note that this definition also covers
water for other domestic purposes, such
as personal hygiene – tooth-brushing,
showering, etc.
EU Directive 98/33 EC of 3 November
1998

3. SUMMARY FOR SMALL SHIPS
About regular analyses
If you bunker water of known quality or produce it
yourselves, it must be analysed at least once a year
– or if you suspect contamination.
If you bunker water of unknown quality, it must be
analysed every time and you must have the results
before using the water. Apart from that, the water
must be analysed once a year.
If maintenance has to be done on the water system,
the water must also be analysed.
Satisfactory quality
The water must comply with various threshold
values for micro-organisms and other contaminants.
Most of the threshold values are European but
there are also a few WHO and Danish threshold
values.
On page 6 of the guidance, you can see what water
is to be controlled for, and in Annex 1 of the
guidance the various threshold values are listed.
Sampling
Samples should be taken for analysis at an accredited laboratory. But if you have the right
equipment and skills on board, you can do it
yourselves. Page 8 of the guidance gives more
details of this.
DRINKING WATER – ON BOARD SHIPS
If the threshold value for E-coli has been exceeded,
you must immediately boil water before use.
Furthermore, you could obtain bottled water at the
next port of call. If you do not immediately know
the source of contamination and cannot stop it,
contact Seahealth for assistance.
If there are other nonconformities, contact Seahealth in the first instance for further assistance
before starting on various actions. Contamination
of drinking water can have major cost implications,
both financially and for the health of the crew. That
is why it is important to prevent contamination.
Guide to prevention
There should be a plan on board for ensuring you
have clean drinking water for the crew. This means:
•
How will you do a risk assessment of the complete drinking water supply system to identify
risks, critical control points and assessment?
•
How will you ensure you have constant operational monitoring?
•
What actions should you take if the water quality
or water system is not in order?
Here is a guide for just such a plan. Remember this
is a general list. So you will need to modify the plan
to match the specific conditions on your ship where
other factors may apply. The points can be included
in the system and routines you already have. You do
not need to have a separate plan.
If analysis results exceed threshold values, you
must take action.
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4. GUIDE TO PREVENTION
System
1. Take a copy of the drawing of the drinking
water system from the ship’s manual.
2. On the drawing, circle where contamination can occur. This might be filters or tank
breather vents. That is, places where the
system can be or is open.
3. Decide how you will prevent water from
being contaminated by the various sources
of contamination. This might for example
be ensuring that the filter is clean before
insertion, that the breather vent has a finely
meshed screen, that the fresh water generator has been cleaned and other programmed
maintenance has been undertaken.
4. Decide whether some of these places
should be regularly controlled or whether
you will do it as a part of routine maintenance. Include the points in the maintenance
system and check/inspection lists that you
already have.
5. Where possible, drinking water tanks must
be opened up, emptied, ventilated and
inspected at intervals not exceeding 12
months.
Additional water treatment
1. Register the additives you use in the water
and determine the correct amount of additives to be used. Do so on the basis of the
manufacturer’s directions in the safety data
sheet and enter the details in to the inspection list.
2. Decide and write down where you will take
on seawater for fresh water production - are
there any special criteria you will establish
on board? Get this included in standing
orders or the company’s SMS.
3. When bunkering, consider which ports of
call have water of a satisfactory quality and
how you can check the quality subsequently.
Operations
1. Check the taste, smell and clarity of water
when you drink it.
2. Describe what to do if it is felt that taste,
smell or clarity are not right, and consider
inclusion in the company’s SMS.
3. Check that hot water is maintained at 60°C
at the heat exchanger (it prevents Legionella bacteria). Include on your inspection list.
4. On the ship’s maintenance system or the
company’s SMS, enter the tests that are to
be taken on drinking water in accordance
with the guidance.
5. If you have cabins on board that you rarely
use, be aware of the potential for Legionella.
So establish a routine requiring showers and
water taps to be flushed before use.
6. When you get results from drinking water
analyses, keep them on board. Scan them
or keep them on file. Check the values and
compare them with the values in Annex 1 in
the main guidance.
If water is contaminated
Make a plan for what to do with water which is
contaminated. Should water be boiled? Will
you supplement with bottled water?
Do you for example have chlorine on board to
decontaminate the system? Get it included in
the company’s SMS.
Seahealth Denmark · Amaliegade 33B, 2 · DK-1256 Copenhagen K · www.seahealth.dk