Why is water tank cleaning important for legionella control?

Keeping water tanks clean is a fundamental part of a water hygiene regime. Here are three key reasons why.

  1. Removing any habitat for Legionella:  Legionella bacteria requires nutrients to grow, these can be found in tanks which over time can gather silt, scale and sediment which provide nutrients for bacteria such as legionella. Water storage tanks can become contaminated with organic matter like leaves or even small rodents if the correct screens are not fitted. Cold water storage tanks can too often be out of sight and out of mind.
     
  2. Water stagnation: stagnant water can provide the habitat in which legionella bacteria can grow.  Scale can trap nutrients and cause a biofilm which can act as a barrier to disinfectants.  By draining and physically cleaning a water tank any scale, sludge and biofilm is removed.
     
  3. Legal Compliance: There are legal obligations surrounding the inspection and if required cleaning and disinfecting of water tanks and maintaining records of the work carried out. These records allow you to prove you are taking the correct action to prevent legionnaires’ disease.

At Dantek our water tank cleaning and disinfection services are carried out by in-house, fully trained, professional water tank cleaners.

All water hygiene contracts with Dantek will include regular cold-water storage tank inspections with the information gathered (including photos) held in a cloud-based compliance logbook. The logbook is included free as part of all contracts, allowing you easy access to all information held about the condition of your cold-water storage tanks. Please get in touch to see how it could work for you.

Recently we carried out a clean and disinfection of a large cold water storage tank, below are photos of before and after the cleaning process.  It is clear in figure 1 there was a high level of sediment visible in the water tank which needed to be removed to reduce the risk of legionella bacteria.

Image of a cold water storage tank before it is cleaned and chlorinated.
Visible sediment in cold water storage tank prior to cleaning and disinfection.
Before and after photo of a large cold water storage tank being cleaned and disinfected.
Cold water storage tank after cleaning and disinfection.