Why do your tanks need cleaning?

Once water is stored it is then open to the environment and therefore susceptible to contamination and degradation. This can allow conditions to develop which supports the growth of micro-organisms. To maintain water quality, the Health & Safety Executive (HSE) recommends regular inspection of water storage tanks, calorifiers and cooling systems and to clean and disinfect them if necessary.

The proliferation of Legionella can occur due to sludge and nutrient build-up in water services. For this reason, ACoP L8 recommends the cleaning and disinfection of cooling systems twice yearly. For other domestic systems such as water storage tanks, a clean and disinfection is only necessary if routine inspection shows it to be required. However, you may decide to clean and disinfect your water systems annually as part of your maintenance program particularly if your business is involved with healthcare of a vulnerable population such as a care home.

Documenting the clean and disinfection

Legionella Management Solutions provide clear Completion certificates for each cleaned tank including the disinfection method and chemical used. This is held on our system and a copy emailed to site. A record of the work carried out is entered into your Logbook. This enables you to demonstrate that you are complying with your responsibilities under ACoP L8.   

Disinfection Agents

Chlorination is applicable when Sodium Hypochlorite is used as the disinfecting agent, this chemical is pH dependant, levels of Free Residual Chlorine should be tested with a test kit rather than test papers.


Hydrogen peroxide is an eco-friendly, multi-component, oxidising biocide.  A highly effective sanitising solution is formed utilising a stable combination of Hydrogen Peroxide and Silver ions.  This combination is so effective that it creates a biocide 20 times more powerful than that of hydrogen peroxide.  Other benefits include:-

  • It is odourless
  • It will not alter the taste, smell or colour of food
  • It is effective in water temperatures ranging from 0 to 95°C
  • No neutralisation is required after disinfection
  • It is biodegradable

Care should be taken to ensure that these chemicals are not used in Healthcare situations where the water feeds medical equipment such as dialysis machines.