Legionella water risk assessment

Legionella water risk assessment

Legionella water risk assessment

What is Legionella?

Legionella is a type of bacteria that causes diseases like Pontiac and Lochgoilhead fever and, worst case Legionnaire’s disease. Exposure to legionella bacteria can be fatal, so it’s perhaps no surprise it’s something no business owner wants.

The disease is contracted by the deep inhalation of small contaminated water droplets known as aerosols or droplet nuclei which are the particles remaining after water has evaporated.

Aerosols can be created by water systems which generate a spray such as showers, spa pools, sprinkler systems and evaporative cooling towers to name but a few.

Therefore, a risk assessment is required for any water system. It is the responsibility of the statutory duty holder to ensure a legionella risk assessment is undertaken, and that there is a suitable legionella control regime in place.

What is Legionnaires disease?

Legionnaire’s disease is a severe form of pneumonia and can be deadly. When it comes to Legionnaire’s disease, everyone’s susceptible. It exists in natural water supplies like rivers, lakes, reservoirs and ponds, but due to the conditions this isn’t where people tend to contract it.

More commonly, Legionnaire’s disease is apparent in places like cooling towers, evaporative condensers, hot and cold water systems and spa pools, where temperatures are high enough to support bacteria growth and the network is insufficiently managed.

The optimum temperature for Legionella growth and multiplication is between 20-45°C – with the provision of nutrients, like rust, sludge, scale and biofilms. Anything lower than 20°C is too cool for the bacteria to activate, and anything above 60°C is too hot for it to survive.

How is Legionnaire’s disease caught?

Legionnaire’s disease is caught by simply breathing in small droplets of water that contain Legionella particles. Employees, visitors, customers, clients and anyone else in your premises run the risk of being exposed to contaminated water, and so it’s essential you have appropriate measures in place.

As an employer, it’s your responsibility to control any risks associated with Legionella exposure with Legionella testing.

How do I arrange legionella assessment and testing?

When you contact us regarding legionella assessment and testing, we’ll arrange the onsite visit for you as quickly as possible. The initial call will give us all the information we need to understand the scale of your business, identify all the assets on your systems, the size of your system and the number of outlets around your building(s) and the type of testing you require.

Our assessor will also need to find out about the types of people using the building such as general ages of staff, and building users in order to identify if susceptible people are present, and also to provide a risk rating for the report.

What is legionella testing?

Legionella testing involves sampling the water in water systems to see if it contains legionella bacteria. Legionella testing should be carried out when there are any potential problems with your water systems. Water samples are taken if your water temperatures are out of control and your water system is not maintaining temperatures.

If a building has been partially or completely shut down for a sustained period, legionella testing should be carried out throughout the entire building to validate systems. During periods of shut down, all water outlets that aren’t used at least once a week need to be flushed, to flush water through the system and prevent stagnation.

What is involved in a legionella water risk assessment?

Once the scope of the assessment has been agreed upon, we will send a qualified and experienced legionella risk assessor to your business premises. The assessor will need to meet with the building manager or responsible person and will need to inspect any previous legionella risk assessment you may have, and any legionella monitoring logbook.

Once this is complete, then the assessor will need to inspect all the water system(s) in full. This will involve inspection and testing of mains cold water supplies, cold water tanks, water heaters, water features, heating systems and all pipework feeding your taps, baths, sinks, showers and outlets.

When will I get the results from legionella testing?

Growing legionella is difficult and it can be a very long process. Once your water samples have been sent to the laboratory, it can take up to 14 days for each sample to grow, but you will receive interim reports keeping you updated of progress.

At RGP we act on interim positives rather than waiting for final results, getting straight into looking at water treatments for your system to identify the problem and generate risk control actions and remedial work. What do I need to do if I receive a positive legionella test?

At RGP, we run through a range of water treatment processes to ensure we cover all bases and get rid of any legionella bacteria as quickly as possible. We’ll start with one sample, then widen the search to more samples, and use chemicals to disinfect your system. After disinfecting your system, we’ll take samples 48 hours later.

How can we help?

Once the onsite element of the system has been completed and the information gathered, we will then electronically send you the report and can also post out a hard copy of the assessment in a presentation folder.

We can then help you further with monitoring programmes, training, remedial works and cleaning and disinfection services. Legionella risk assessments need to be reviewed regularly (on average every 2 years), or if conditions change, such as:

  • Changes to building use
  • Significant changes to the water system
  • Availability of new guidance

There is a legal duty to assess the risk and maximise the control to legionella bacteria, but there is no approved code of practice. A professional risk assessment is not legally required, it’s however a good way to ensure your water supply is safe.

We are here to carry out a legionella testing, identify sources of risk, identity risk of exposure and assess the risk of legionella, control the risk and advise control measures, in relation to legionella bacteria in all water systems.

No building is too big or too small for our team, and we’re flexible to ensure we provide our custom-ers with testing to suit your specific needs. At RGP, we’ll defend your business against an outbreak by providing a thorough risk assessment and offering guidance to keep you safe and compliant.