Water Testing on vessels, ships and water tanks in remote locations

According to regulations, which came into effect August 2013, ships’ drinking water supplies have to be tested regularly. To help with the compliance to this requirement, we have created this guide.

“Water is essential to sustain life, and a satisfactory (adequate, safe and accessible) supply must be available to all. … Every effort should be made to achieve a drinking-water quality as safe as practicable.“ WHO Guidelines for Drinking Water Quality (2008)

What are the current regulations:

  • Maritime Labour Convention (MLC) 2006, Standard A3.2 – Food and Catering, para 7 – “the competent authority shall require that frequent documented inspections be carried out on board ships, by or under the authority of the master, with respect to … supplies of drinking water”
  • World Health Organisation (WHO) Guide to Ship Sanitation (2011) & Guidelines for Drinking Water Quality (2008) – “Recommended parameters to be monitored: E. coli or coliforms; Chlorine residual (daily); … pH (daily); … Corrosion-related contaminants – iron & copper.”

Ship owners, managers, crewing agencies should understand the regulations and develop and implement measures to ensure compliance. A copy from the UK goverment can be seen here. Annex 2 relates specifically to freshwater loading and supply arrangements, disinfection, storage, distribution systems and maintenance.

To avoid port state control problems, it is advised to issue a Declaration of Maritime Labour Compliance (DMLC) for all ships, which can serve as evidence that each ship meets MLC standards. A part of that is the provision of potable water test kits for each ship.

Potential problems associated with potable water on ships:

  • Limited space on ships means that potable water systems are likely to be close to hazardous substances / sewage / waste streams / sources of heats; evidence from outbreaks has indicated that contamination with sewage is one of the most common causes for outbreaks of water borne diseases on ships
  • Ships are considered one of the highest risk areas for Legionnaires’ disease
  • Water production on board through Desalination, Reverse Osmosis or Evaporation can be associated with its own potential health problems
  • Corrosion in plumbing may lead to metals leaching tino water. Desalinated water produced on board may be corrosive and the saline atmospheres may be have additional corrosive effects.

What to look for when choosing a potable water testing kit:

  • The kit should contain all tests as required by regulation
  • Easy and safe to use – even for inexperienced users
  • Clear and easy to understand instructions
  • Reliable and easy to understand test results
  • Minimum waste and hazardous materials
  • Economic but reliable solutions
  • Long shelf life

Monitoring of water & water systems

“Regular water quality monitoring must be performed to demonstrate that source water … and potable water .. are not contaminated with fresh faecal material or other microbial and chemical hazards.”  WHO Guide to Ship Sanitation (2011)

Below are some of the water tests recommend by WHO:

Source water: basic testing of source water includes E.coli or thermotolerant (faecal) coliforms, disinfectant residual, corrosion-related contaminants (like iron, copper) and aesthetic parameters (odour / colour / taste).

  • Corrosion-related metals such as lead, nickel, iron, cadmium, copper can leach from plumbing systems into the water, where they can cause health concerns after consumption.
  • Tests for disinfectant residuals, like free chlorine, to ensure samitising agents have been used treat the water.

Testing of water produced on-board:

  • If re-mineralisation (ie addition of calcium carbonate to desalinated water) is used for on-board water production, then tests for pH and hardness should be carried out.
  • Distillation/Evaporation: water which has been produced below 80°C needs to be disinfected, tests for disinfectant residuals are recommended

To avoid hazardous chemicals being added to the water (ie coating from tanks), water should not be corrosive to surfaces fixtures and fittings – control pH, alkalinity & temperature of water

Where chlorine is used for disinfection, a satisfactory chlorine residual should be 0.5 – 1 mg/l (ppm) for free chlorine, ideally at a pH of 8 or below.

Recommended regular tests on board and their typical values include:

  • Bacteria, incl E.coli (0 cfu/100ml) ,
  • pH (6.5 – 9.5) & alkalinity,
  • Hardness (>100 mg/l ppm),
  • Free chlorine (<5mg/l),
  • Total chlorine,
  • Various metals including lead (10 μg/l), copper (2000 μg/l), cadmium (3μg/l ), iron (200μg/l ),  nickel (70μg/l ), zinc (3000μg/l ),
  • Legionella (<100 cfu/100ml).

[legend: 1ppm = 1mg/l, 100μg/l = mg/l = ppm]

Frequency of testing

According to MLC 2006 “frequent documented inspections” of drinking water supplies should be carried out. Latest recommendations suggest that the master of the ship must ensure that supplies of food and drinking water are inspected at least once a week.

The World Health Organisation specifies further:

“Source water is monitored at the port to ensure that water is safe. The ships master is responsible for operational monitoring the quality of source water: disinfectant residuals and pH (e.g., daily); microbial quality of treated water, particularly after maintenance or repairs. The frequency of monitoring should reflect the probable rate of change in water quality. For example, monitoring of drinking-water on ships maybe more frequent when the ship is new or recently commissioned, with frequencies decreasing in the light of review of results. Similarly, if the ships water system has been out of control, monitoring following restoration of the system would be more frequent until it is verified that the system is clearly under control.”

ILO Convention78 recommends “Physically check quality of water at random using different outlets.”

The Solution: SimplexHealth® & Watersafe® Water Quality Test Kits with fast and reliable results

Water test kits are available which are easy to use, safe and cost-effective. These water tests are already used by a number of shipping operators, yacht owners as well as companies with water tanks in remote locations. They can be used to test potable water for various important elements.

How do the tests work? The water tests are easy-to-use in 3 simple steps: Simply dip the test strip into the water sample, wait and then compare the colour change to the colour chart:

Chlorine, pH, hardness, nitrate, copper, total alkalinity, sulfate, iron tests – using test strips:

  • Dip one test strip into water sample.
  • Remove, shake once briskly, and wait briefly.
  • Match colour of test strips with provided colour chart in kit.

Bacteria – with a bacteria mug:

  • Fill the bacteria mug, which is provided in the test kit, with the water sample and recap bottle.
  • Incubate for 24 hours or 48 hours, depending on temperature.
  • After incubation time, observe the colour of the sample.

Lead, pesticides – using a vial & a test strip:

  • Using the dropper pipette, which is included in the test, place water sample into test vial.
  • Place on a flat surface and put test strips into test vial.
  • Wait 10 minutes, then read results.
Benefits of SimplexHealth water testing kits:

  • Long shelf life
  • Compact and portable test kits
  • Accurate results instantly, only the bacteria test result is available after 24hrs – 48 hrs
  • Kit includes everything to complete the water tests
  • No special training or expertise required
  • Easy to understand results
  • No need for calibration or any additional equipment
  • No glass ampoules to break, no mess
  • Monitoring solutions for water with optional extras
  • Safe and easy to use, a MSDS is not required

Choose from our range of multi-packs:

SimplexHealth 12-in-One Watersafe 10-in-One Watersafe 8-in-One
Tests per standard kit Test designed to test 2 water samples for 11 common contaminants & 1 water sample for bacteria** Test designed to test 1 water sample for 10 common contaminants Test designed to test 1 water sample for 8 common contaminants
Total Coliform Bacteria, incl. E.Coli Presence/Absence Presence/Absence Presence/Absence
Lead, Pesticides Presence/Absence Presence/Absence
Nitrate 0, 2, 10, 20, 50 ppm (mg/l) 0, 0.5, 2.0, 5.0, 10, 20, 50 ppm 0, 0.5, 2.0, 5.0, 10, 20, 50 ppm
Nitrite 0, 0.2, 1, 1.5, 3 ppm (mg/l) 0, 0.15, 0.3, 1.0, 1.5, 3.0, 10 ppm 0, 0.15, 0.3, 1.0, 1.5, 3.0, 10 ppm
pH 2, 4, 5, 6.5, 8.5, 9.5, 10.5, 12 6, 6.5, 7.5, 8.5, 10 6, 6.5, 7.5, 8.5, 10
Total Hardness 0, 50, 120, 250, 425, 1000 ppm 0, 50, 120, 250, 425 ppm 0, 50, 120, 250, 425 ppm
Total Chlorine 0, 0.1, 0.2, 0.5, 0.8, 4, 10 ppm 0, 2.0, 4.0, 10 ppm 0, 2.0, 4.0, 10 ppm
Free Chlorine 0, 0.05, 0.2, 0.6, 1.5, 4, 10 ppm (mg/l)
Iron 0.0, 0.05, 0.1, 0.3, 1.0 ppm (mg/l) 0, 0.1, 0.3, 1.0, 5.0 ppm
Copper 0.0, 0.1, 0.5, 1.0, 2.0 ppm (mg/l) 0, 0.5, 1.0, 2.0, 5.0 ppm
Hydrogen Sulfide 0.2 ppm to ≥ 2 ppm
Total Alkalinity 0, 40, 80, 120, 180, 240, 500 ppm
Sulfate 0, 250, >500 ppm (mg/l)
Price per kit (RRP incl VAT)* £29.99 £27.99 £22.99
Cost per test (based on RRP incl VAT)* £1.30 £2.79 £2.87

* volume discounts for orders above 10 units available, please contact us for details

Additional tests available:

  • Legionella water test to test for Legionnaires’ Disease – Get accurate on-site results in 35 minutes
  • Metals check, testing total amount of metals in water – Measure the total amount of metals in water in less than 3 minutes
  • Specific heavy metals tests, including Cadmium, Aluminium etc
  • **Additional bacteria test kits available from SimplexHealth as well as Watersafe
  • We also offer a wide range of individual test strips, like Chloride, Metals – to view the full range please click here


Further references and sources:


Disclaimer: Only opinions based upon our own personal experience or information detailed in academic journals or other publications is cited. This has been done exclusively for anyone who is interested in this subject but is not intended to replace proper analysis. We cannot accept responsibility and liability of any kind which may result from the application of this information. We always recommend to consult an expert to discuss any test results or get a full recommendation on the specific subject and specific to your situation by an expert.
This information is owned by SimplexHealth and you do NOT have the right to reprint, sell, auction or distribute this information.

There are strict standards for the quality of drinking water within Europe mainly laid down in the EU Drinking Water Directive (98/83/EC). These are based on advice from the World Health Organisation (WHO).