Back to Business – Legionella Risks in your Premises

Has your building been closed or had reduced capacity during the Coronavirus (COVID-19) pandemic? If so, there is a risk of legionella developing in water systems that have remained dormant.

All employers, self-employed and those in control of premises (such as landlords) have a duty to protect people by identifying and controlling the risks associated with legionella. As you begin to re-open your premises you should conduct a legionella risk assessment, particularly when you:

  • reinstate a water system, or start using it again
  • restart some types of air conditioning units

CCRS Brokers are experts in risk management and can provide you with expert advice and guidance around managing the risks associated with building re-opening.

Contact CCRS

Our downloadable Legionella Risk Assessment Checklist will help you identify any potential risks of Legionella bacteria.

Download Now

What Is Legionnaires’ Disease?

Legionnaires’ disease is a form of walking pneumonia caused by legionella bacteria that is commonly found in the built-in water systems of hotels, hospitals, office buildings, flats and houses. While the fatality rate of those infected ranges between 5 to 30 per cent, the disease is fatal in roughly 50 per cent of patients who go untreated. Most people can successfully be treated with antibiotics.


How Legionella Bacteria Spreads and Grows

Legionella bacteria are naturally found in water-based environments. Cooling towers, central air conditioning systems and hot and cold water systems are all ideal environments for legionella to grow. Your premises are at greater risk of contamination if they have a large number of cooling towers, air conditioning units, spa pools, hot tubs, showerheads or other water outlets that can generate ample amounts of water droplets.

Other factors that can increase the risk of contamination are:

  • Water temperatures of 20C to 45C in all or some parts of the system, which is the optimal temperature range for bacteria growth
  • Stored and/or recirculated water that has not been replaced or treated
  • Tanks or pipes that contain deposits of rust, sludge, organic matter and other biofilms, which provide nutrients for bacteria growth

People contract Legionnaires’ disease by inhaling the contaminated airborne water and/or soil particulates that are dispersed through the air conditioning vents and/or water outlets.

It is therefore essential that before restarting any water systems or air conditioning units, you must assess the risks of legionella being present.

You should also conduct regular risk assessments in order to mitigate the risk of employees, tenants or customers developing Legionnaires’ disease.


Safeguarding Against the Risk of Contamination and Infection

There are some risk-preventive measures that you can adopt to control the risk of legionella bacteria contamination:

  1. Perform regular quality testing of water stored in tanks. This can be done by a water treatment company or by yourself (if you decide to test yourself, please refer to the HSE’s Legionnaires’ disease Technical Guidance
  2. Remove redundant pipework to ensure that water cannot stagnate anywhere in the system.
  3. For those hot and cold water outlets that are used infrequently, flush them weekly to prevent stagnation. If you haven’t been able to do this during lockdown, ensure systems are cleaned and disinfected before the building is reopened.
  4. Ensure that water tanks have tight seals so that no debris is able to contaminate the system.
  5. Set temperature control standards of the calorifier to ensure that water is stored at 60C.
  6. Larger air conditioning units may present a risk if they have not been in use for a significant period as they have more areas where water could stagnate. When you review your risk assessment, decide what the risks are for your units and if they need to be cleaned before they are turned on.
  7. Treat the water stored in tanks or other systems to limit or control the growth of micro-organisms.

Use our Legionella Risk Assessment Checklist to help identify potential risks.

If you have five or more employees, you are legally obligated to record any significant assessment findings, such as any groups of employees particularly at risk of Legionnaires’ disease and any risk management procedures you undertook to control legionella risk. If you have fewer than five employees, you are not required to write anything down, but keeping written records is generally a good practice. Your records should contain the following information:

  • The employees responsible for conducting the Legionnaires’ disease risk assessments and implementing the risk management procedures
  • Significant findings from the risk assessment
  • Plans for implementing the risk management procedures
  • Records of any inspections

The risk of your premises becoming contaminated with Legionnaires’ disease is one that can be easily managed – if you take the appropriate preventive measures. Regularly conducting inspections of a property’s pipework as well as its water quality can greatly mitigate the risks of infection.

For more information on your responsibilities as an employer or property owner and on risk management guidance, contact CCRS Brokers today.