What’s lurking in your workplace water supply could make you sick. Really sick. We all need water, but if certain bacteria are allowed to build up, contaminated water can cause serious diseases. As well as being a vital workplace health and safety procedure, legionella testing is a legal duty for all UK employers and landlords.
Every business should regularly test its water supply for legionella bacteria. If you happen to breathe in water droplets that contain legionella bacteria, you could develop a life-threatening disease, and more than one person will likely become ill.
Keep reading to learn about legionella testing and water analysis.
Why Legionella Water Testing Is Important
Regular legionella water testing is the best way to prevent disease outbreaks.
Legionella bacteria aren’t always hazardous. In fact, most natural freshwater bodies have some level of this bacteria. Legionella bacteria generally don’t multiply in amounts significant enough to cause disease in the wild. Only in manufactured structures and water storage areas can these pesky bacteria multiply and get the nutrients they need to become a severe health hazard.
What’s really worrying is that there’s no easy way to know if you’ve got legionella bacteria in your water. You can’t tell if you have an infected water supply just by looking at it. There’s no telltale discolouration or bad smell. The only way to know is by having professional legionella testing done.
While legionella bacteria are problematic, you can keep your workplace safe and protect yourself, your co-workers and the public with the correct procedures.
Suppose you’re an employer or a landlord – you have a legal obligation to safeguard the health and safety of your employees, tenants, and the public. Your obligation includes taking steps to make sure your water is free from legionella bacteria. The legislation covering these responsibilities includes:
- The Health and Safety at Work Act 1974
- Control of Substances Hazardous to Health Regulations 2002 (COSHH)
Not conducting legionella water testing puts people at serious risk. It can also put you in breach of UK health and safety laws. You have to occasionally arrange legionella testing to avoid heavy fines and penalties and keep people safe. It’s a no-brainer, really.
Legionella Water Testing and Legionnaires’ Disease
So, you might wonder what the risks associated with legionella bacteria are.
If a person inhales a water droplet that contains high levels of legionella bacteria, they can develop one of a series of pneumonic and non-pneumonic diseases. These diseases are known collectively as legionellosis. The legionellosis family includes the non-pneumonic form called Pontiac disease – a flu-like infection lasting two to five days. Pontiac disease certainly isn’t fun, but it’s not fatal.
The same can’t be said for another form of legionellosis, the pneumonic condition Legionnaires’ disease. In most cases, a person with Legionnaires’ disease will require medical treatment. Treatment consists of courses of antibiotics. There is no vaccine for Legionnaires’ disease and recovery can take weeks.
But, unfortunately, not everyone gets better. Legionnaires’ disease rapidly worsens during the first week if not treated. The fatality rate in cases where the person is reasonably healthy before infection is about 10%.
For smokers or people with suppressed immune systems, the fatality rate can be as high as 80% without immediate treatment. In worst-case scenarios, Legionnaires’ disease results in shock multi-organ and respiratory failure, leading to death.
The amount of legionella bacteria a person needs to inhale to become infected is believed to be very low. There have been accounts of people becoming ill with Legionnaires’ disease after only a short exposure time. People have also caught the disease when they’ve been over three kilometres away from the source of the outbreak, according to data collected by the World Health Organization (WHO).
When to Test for Legionella
The Health and Safety Executive (HSE) guides businesses and landlords on the best practices for legionella testing.
The HSE recommends that “water samples should be analysed for Legionella periodically to demonstrate that bacteria counts are acceptable.”
Which is admittedly vague. The HSE clarifies the guidance by stating that the frequency of legionella water testing should be determined by the results of a thorough risk assessment of the water systems. In places with high-risk systems like spa pools, cooling towers, and evaporative condensers, the HSE recommends quarterly legionella testing.
The HSE advises legionella testing should be done:
“where there is doubt about the efficacy of the control regime or it is known that recommended temperatures, disinfectant concentrations or other precautions are not being consistently achieved throughout the system.”
So, if you have a high-risk area like a steam room or you don’t know the maintenance history of your water systems, it’s best to arrange for regular professional legionella testing.
How Does Legionnaires’ Disease Testing Work?
Legionella bacteria can accumulate in water between 20-45°C, where they can find enough nutrients to survive. The harmful microbes like to breed in stagnant water and thrive on things like limescale, rust, sludge, and biomatter.
To test for the presence of legionella bacteria, a professional microbiologist must collect a water sample and have it tested in a laboratory. The procedures surrounding collecting and testing a water sample must be done per British Standards. The person collecting the sample and the laboratory must be accredited by the United Kingdom Accreditation Service (UKAS).
Three methods are used to determine if water has a high level of legionella bacteria:
- The Culture Method:
A water sample is collected and confined in a petri dish. The sample is tested with biochemicals to determine if legionella bacteria are present. UKAS approves this method and it’s the most common.
- The Polymerase Chain Reaction (PCR) Method:
Water cells are concentrated through membrane filtration, sonication, and heating. This process releases DNA, which can be analysed to detect legionella bacteria. The PCR method is usually used to monitor severe legionella outbreaks.
- Rapid Swab Testing:
Rapid swab kits are used to analyse biofilm samples for the presence of legionella bacteria. These tests provide approximate results only and are not substitutes for professional legionella water testing in laboratory conditions.
How Long Does a Laboratory Test Take?
The culture legionella testing method can take 10 to 14 days to complete. While this method is slow, it’s less expensive than the PCR method and much more reliable than rapid swab testing. If your water is found to have high levels of legionella bacteria, the laboratory will notify you as soon as this is evident.
Why Legionella Awareness Training Matters
When an outbreak of legionella bacteria occurs, the result can be devastating. In 2002, seven people died and 120 more were seriously ill after an outbreak in a council arts and leisure facility in Barrow-in-Furness, Cumbria.
More recently, in 2022, the HSE brought legal action against a West Midlands firm because of a legionella outbreak in the company’s cooling towers. Ultimately, five people became ill and the firm was forced to pay a fine of £50,000 and £11,000 in costs.
Knowing how to perform a legionella risk assessment is crucial for any landlord or business owner. This knowledge can help save lives and protect your business.
Our Legionella Awareness training courses teach you and your team how to prevent legionella outbreaks. It’s an effective way to learn how to recognise and control the risks of legionella bacteria.
