The most common place to find the legionella bacteria is in water.

In natural water systems such as lakes and streams, it occurs in low levels that are not harmful to human health. However, in man-made systems, legionella can thrive and multiply, presenting serious health risks.

Where there is legionella in these water systems, it’s important to control its spread.

Legionella treatment is essential for maintaining safe water systems and managing legionella risk. One key way of treating legionella in water is by cleaning pipework to remove and prevent the build-up of biofilm.

Alongside this type of specialist water treatment, there are other steps you can take to control legionella in water.

Causes of Legionella Contamination

There are major factors that contribute to the contamination of water systems by legionella.

• Where water is lying stagnant for long periods, in a system or pipework, this can lead to the growth of legionella and other pathogens.

Biofilm is a key enabler of legionella growth. Bacteria create this slimy substance, which forms on the inside of water pipes. It protects legionella bacteria and helps it spread.

• Lukewarm water, 20°C to 45°C, helps legionella to grow.

• Dead legs, or dead ends, in pipework are places where legionella can thrive. These are areas of pipe in a network that receive very little or no water flow.

• Corrosion, and a lack of corrosion control, can create the ideal environment for legionella.

• If there is a disinfectant added but this is insufficient, then legionella may continue to thrive in a water system.

Various types of environment are susceptible to legionella growth. These can be large, complex plumbing systems. This is why there can be outbreaks of legionnaires’ disease in hospitals and on cruise ships.

There are also risks where water sources generate aerosols or fine mists of water, which people end up ingesting. This applies to industrial settings in particular, where there are cooling towers and processing systems.

Three main things contribute to legionella risk:

• Conditions that allow legionella into the water system
• Growth and spread of legionella within the system
• Transmission of legionella to people via inhalation of aerosol or small water droplets.

Controlling Legionella in Water

HSE recommends temperature control as a basic measure for controlling legionella in water. This requires operating water systems at temperatures that will prevent the growth of legionella.

• For cold water, this means temperatures under 20°C. For hot water, cylinder storage should be at 60°C or higher, and distribution of hot water at 50°C or higher.

• Another key factor in legionella growth is stagnant water. Therefore, it is important to frequently flush out any outlets that have infrequent use and to remove any dead ends or dead legs in pipework.

• Controlling legionella begins with how you design water systems in the first place. HSE advises that pipework should be as direct and as short as possible. It should have adequate insulation.

• Water systems should be made of materials that will not encourage legionella growth.

• For tanks and other storage vessels, lids and insect screens will help prevent contamination.

Biocide Water Treatments

Using an effective disinfectant in water systems can significantly reduce legionella risk and help control or prevent the growth and spread of the bacteria.

By ensuring that pipework is clean and free of biofilm, you can lay a good foundation for keeping water systems clear of pathogens.

Oxyl-Pro is a proven biofilm remover and an officially accepted method for disinfecting water systems against legionella.

How to Treat Legionella Pneumonia

Legionella causes legionnaires’ disease, which is a severe and sometimes lethal form of pneumonia.

Where there is insufficient control of legionella, this can lead to contamination of water systems and to people contracting the disease.

If this happens, what is the treatment for it?

The sooner the person with the illness is treated, the better. Antibiotics can be effective, but in some cases, the person may be given oxygen to help with their breathing. In more severe cases, they will need help to breathe in intensive care.

Most people with legionnaires’ disease will make a full recovery, but recovery times can vary, and be quite long, depending on the individual.

Reducing Legionella Risk

The best way to reduce the risk of legionella and legionnaires’ disease is to control the bacteria and apply an effective water treatment.

For more information about legionella control, water treatments and Oxyl-Pro, please call us on +44 1606 851 782, email or complete our contact form.