Does your water tank need a clean?

How to clean your water tank

Purchasing a GRP water storage tank can be a big decision as to which one is the right tank for your configuration, however if it is supplying water for human consumption, It is recommended that if the system or part has been substantially altered or if an engineer has entered the tank for maintenance or remedial purposes in a manner that may lead to contamination, the tank will  need a clean and disinfection.

Even though the tank or parts are new and would be a fit state to set up and go, if any bit of debris enters the tank, via fixing an outlet to the tank, drilling the valve into position, engineer entering the tank to fit extras, this can lead to bacteria building up in the tank once filled. So its best practice to have the tank cleaned once installed, so you are starting off on the right foot.

Certification will be issued once a clean and disinfection has been performed, so peace of mind, that everything was set up correctly initially.


If i do not get my tank cleaned and disinfection, will my tank still be ok?

If you are supplying water for human consumption, it is best practice to have a clean after installation and annually (ACOP L8).

Water can harbour many different types of bacteria, with some being harmful if consumed by humans. One harmful bacteria which is most commonly knows is Legionella disease.

Outbreaks are very low, however outbreaks of the illness occur from exposure to legionella growing in purpose-built systems where water is maintained at a temperature high enough to encourage growth. If conditions are favourable, the bacteria may multiply, increasing the risks of the disease, and it is therefore important to think about commissioning of your water tanks.

A tank inspection, clean and chlorination of a tank and its services is recommended not only on an annual basis and when there is visible evidence of the following -

  • Sediment
  • Stagnant water
  • Biofilm
  • Corrosion
  • Flora growth
  • Animal Contamination

To prevent and for peace of mind we offer the below inspection, clean and chlorination of your GRP water tank.

Before and After Commissioning Water Tank Images

Before & After Your Water Tank Is Cleaned
Commissioning Before & After Diagram

Commissioning Examples

Commissioning Example
Water Tank Commissioning Example

Clean & Disinfect Cold Water Storage Tank Work to comprise:
  • All labour & materials to carry out the following:
  • Inform the relevant personnel of any interruption, disturbances or potential of such, to the water supply that may occur
  • Carry out a visual inspection of the storage tank ,logging and reporting any leaks or problems before commencing work( if the tank has a division then each compartment will be cleaned individually ensuring a constant water supply).
  • Isolate the Incoming and outgoing water supply (checking correct operation of valves)
  • Drain down the water storage tank or individual compartments
  • Photograph internal surfaces prior to commencing the tank clean
  • Using clean water only, clean all internal surfaces using non-metallic equipment and tools
  • Remove all debris from the inside of the tank where possible
  • Re- photograph clean internal surfaces
  • Commence refilling the tank with mains clean water via Inlet valve
  • Check & clean filters in overflow, warning pipe and tank breathers (if accessible)
  • Disinfect the tank and leave to stand for 60 minutes
  • Test water for correct PPM levels
  • Take any samples (if ordered)
  • Place the tank online
  • Issue a full report and certificate of compliance in accordance with ACOP L8 (2013) requirement

Certification of what you will received once Clean and Disinfection has been carried out.

Example of Certfication

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