Legionella Control – What Is Legionella?

Ames Group offer Legionella control services and legionella risk assessment, UK wide. Legionella is the name given to a type of water-borne bacteria which causes three potentially fatal diseases which are collectively known as Legionellosis. Legionella also causes infections that lead to Legionnaires’ Disease. Legionnaires’ Disease is a potentially fatal form of pneumonia and typically affects men more than women.

– Legionella pneumophilia belongs to the genus Legionella.
– Around 50 species of Legionella have been identified.
– L.pneumophilia is responsible for approx 90% of cases.
– It thrives in soil and water environments.
– At low temperatures the bacteria can’t multiply.
– At high temperatures over 60c the bacteria dies.


Our Legionella Control Service: Risk Groups

Legionella controlOur legionella control service is design to keep legionella under control and prevent the spreading of the disease. The risk of contracting a legionellosis disease has been shown to be greater as age increases.  There are however some people with a significantly higher risk including:

  • Smokers & people with respiratory diseases
  • Heavy drinkers
  • People with diabetes, heart disease or lung conditions
  • The over-45s
  • People with kidney disease
  • Those with impaired immune systems

How Is Legionnaire’s Disease Contracted?

People are usually affected by legionellosis after breathing in water droplets which contain legionella bacteria. This is why it is vital for any commercial business to have a legionella control strategy in place.

Diseases Caused By Legionella

‘Legionellosis diseases’ include Legionnaires’ Disease, Pontiac Fever & Lochgoilhead Fever. Legionnaires’ disease is the most serious that the bacteria can cause.  The disease causes symptoms of pneumonia.



Where Does Legionella Come From?

While Legionella bacteria occur naturally, they seldom form significant colonies. Artificial water systems typically offer a warmer and more favourable environment for legionella to multiply. Without a testing and control or cleaning regime in place, legionella colonies in hot or cold water systems easily thrive.

Unfortunately, water jets, sprinklers, evaporators, misters and showers make the problem worse by creating a water aerosol. Fine water droplets – in an affected water system – spread disease very effectively.


Water Systems Which Support Large Legionella Colonies

Unfortunately there are a wide range of conditions which encourages legionella bacteria to multiply.

High-Risk Water Systems Commonly Offer Bacteria:

As with any living organism legionella bacteria need certain elements in order to survive and for the bacteria to be a danger to people the following 4 key elements need to be in place:

  • Habitat – Shower Heads, Sprinkler hoses, taps and hot water cylinders.
  • Food Source – sediment, scale, other bacteria and certain natural organic by products found in certain hair care products.
  • Warm Temperatures – Legionella bacteria thrive in temperatures of 20Oc – 45 Oc.
  • Aerosol Release – Water that is released as an aerosol can be a risk should it be contaminated with legionella bacteria

Cooling towers, recirculated systems and water outlets commonly exhibit these features. Less widely known however is the risks posed by water services such as car washes and public showers.


Water Systems Posing A Clear Risk

Air conditioning systems, cooling towers, spa pools, jacuzzis, recreational and swimming pools are all potential legionella risks. However any hot or cold water system may pose a threat.

Equipment such as dental apparatus, NHS departments, office air-conditioners, washing facilities, vehicle cleaning machines and food manufacturing sites are a small selection of those which need regular assessment.

Industrial facilities such as manufacturing sites using ‘process water’ and also equipment such as water towers (cooling towers) also present a very real health risk. If not properly managed a great deal of affected material can be accidentally distributed.

Unfortunately, most water systems pose a risk, so these examples are far from exhaustive.



How to Prevent Legionella

Having your property checked by a certified health and safety company is the first step of prevention.

Legionella becomes a serious health concern when it spreads within man-made water systems such as shower heads, cooling tanks, hot tubs and large-scale plumbing systems.

1. Understand What Legionella is

Prevention is better than a cure, and Legionella can easily be avoided if the correct precautions and regulations are adhered. Understanding what Legionella is is the first step for prevention.

legionellaLegionellosis is the collective term for diseases caused by the legionella bacteria, the most threatening of which is Legionnaires’ disease. Legionella bacteria, if left untreated, can lead to Legionnaire’s disease, which is can be a fatal form of pneumonia.

Educating yourself on Legionella is essential, because you will be able to know what to look out for and what actions to take to ensure it doesn’t jeopardise the health and safety of your property.

2. Use Temperature Control

legionella testingControlling Legionella essentially boils down to controlling the temperature of your water system(s). Ensuring your water systems are operating at temperatures that prevent Legionella bacteria from forming is essential. We have outlined some key factors to address in regards to keeping your water temperatures at appropriate levels:

  • Cold water should always be stored and distributed at temperatures below 20 degrees to ensure Legionella bacteria cannot form and multiply.
  • Hot water must be at temperatures exceeding 50 degrees – only a certified Legionella risk assessor will be able to efficiently carry out this task.
  • Storage cylinders should always store water at temperatures above 60 degrees.

AMES strongly advises inspecting your water system at least once a year to ensure your water temperatures are in accordance with your risk assessment guidelines.

3. Conduct Water Analysis Checks Periodically

legionella testingStagnant water is the ideal breeding ground for Legionella bacteria growth. The longer water is left stagnant, the more time Legionella bacteria has time to form and develop.

We strongly advise checking and removing redundant pipe lines (pipelines or pipework that were once used but are no longer in use). Flushing taps and shower heads that see rare usage is also advised, as this again provides a strong breeding platform for Legionella bacteria.

4. Keep Water Clean and Maintained

legionellaPreventing the growth of Legionella bacteria can be accomplished simply by cleaning and performing routine maintenance. Flushing the water from outlets that aren’t used frequently is important (once a week is advised). Additionally, hot water systems should be drained and checked for any signs of rust or debris and cold water tanks should be cleaned periodically.

You can find out more about how to effectively clean hot and cold water systems by reading HSE’s article here.

It’s important to develop a clear plan of action to ensure that you are doing everything possible to actively prevent Legionella growth. Cleaning and ongoing maintenance is an essential part of this, and as such it’s important that infrequently used outlets are flushed weekly (minimum), cold water tanks are cleaned periodically and hot water cylinders should be drained and checked for signs of corrosion and debris.
These are just a few suggestions from W.E.T which form part of a control scheme, which is required by law. If you want more information on Legionella control or are concerned that your water system isn’t compliant, then contact the team at W.E.T who would be happy to help and advise.

5. Regularly Check Hot Tubs

legionella hot tub

Many people who purchase hot tubs and other artificial heating pools fail to carry out the necessary Legionella checks.

As mentioned previously, Legionella breeds best in warm water temperatures. However, chlorine and other disinfectant chemicals commonly used in hot tubs are notoriously difficult to maintain at the levels required to eliminate Legionella bacteria.

Disinfectant and other chemicals must be checked regularly to ensure they are able to eliminate the threat of Legionella bacteria. Additionally, hot tubs should be cleaned on a regular basis to ensure no stagnant water is present (this is especially important during in winter, or during the colder months).

If you are concerned about the condition of your hot tub, contacting a Legionella risk professional is encouraged, and this is something we can help with.

You Do Not Need to Worry if…

  • You own an air conditioning unit – these do not use water to cool the air, meaning there is no platform for Legionella to grow and spread.
  • You have had your property and appropriate water systems checked for Legionella in the last year.
  • AMES have carried out a Legionella risk assessment.

Do You Require a Legionella Risk Assessment?

AMES carries out professional, Legionella risk assessments across Birmingham. If you’re worried about the condition of your water systems, or you haven’t had your systems checked recently, we can carry out a swift, no hassle Legionella assessment to ensure you are complying with standard property health and safety regulations.


AMES offer the full range of services recommended by the government to tackle the risks involved in controlling legionella risk in water systems.



For more information on legionella risk assessment, water chlorination treatments and water sampling and analysis, contact AMES UK using the details below.

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