Straight away, legionella management is here to stay as it is so present and can become present in any type of water system. Whether residential or commercial, it doesn’t matter. Legionella can most of all become a presence and factor in systems not properly managed or maintained. It helps in any commercial site and location to have a full and proper management plan in place to best be able to combat it before its too late.
What is legionella? In detail..
Legionella bacteria is commonly found in water. The bacteria multiply where temperatures are between 20-45°C and nutrients are available. The bacteria are dormant below 20°C and do not survive above 60°C. Legionnaires’ disease is a potentially fatal type of pneumonia, contracted by inhaling airborne water droplets containing viable Legionella bacteria. Such droplets can be created, for example, by: hot and cold water outlets; atomisers; wet air conditioning plant; and whirlpool or hydrotherapy baths. Anyone can develop Legionnaires’ disease, but the elderly, smokers, alcoholics and those with cancer, diabetes or chronic respiratory or kidney disease are at more risk.
Next steps and what you need to do
Health and social care providers should carry out a full risk assessment. This will need to be done in and of their hot and cold water systems and ensure adequate measures are in place to control the risks. There is usually a very straightforward checklist from which you can form a basis to work out what you need to do.
The importance of having proper and correct water temperature control in place
In detail, all of the following points need to be factored in for the correct management and control of legionella:
- Hot water storage cylinders (calorifiers) should store water at 60°C or higher.
- Hot water should be distributed at 50°C or higher (thermostatic mixer valves need to be fitted as close as possible to outlets, where a scald risk is identified).
- Cold water should be stored and distributed below 20°C.
A competent person should routinely check, inspect and clean the system, in accordance with the risk assessment. You must identify ‘sentinel’ outlets (furthest and closest to each tank or cylinder) for monthly checking of the distribution temperatures. You should also check the hot water storage cylinder temperatures every month and cold water tank temperatures at least every six months.
Stagnant water also favours Legionella growth. In order for you to be able to reduce the risk, you should remove dead legs / dead ends in pipe-work. You should also look to flush out infrequently used outlets (including showerheads and taps). It is also advised to at least weekly and clean and de-scale shower heads and hoses at least quarterly. Cold-water storage tanks should be cleaned periodically and water should be drained from hot water cylinders to check for debris or signs of corrosion.
Other points to consider
Water samples should be analysed for Legionella periodically to demonstrate that bacteria counts are acceptable. The frequency should be determined by level of risk, in accordance with the risk assessment. In any case, a good risk assessment is key. It will be able to flag up any major and alarming risk factors. It will also raise points of how to better manage your water system infrastructure. As you can imagine, systems come in all shapes and sizes. With this, there will be the need for different levels of management to be undertaken.
In a commercial environment, such as a hotel
Legionnaires’ disease is a serious type of pneumonia (lung infection) caused by Legionella bacteria. It can be associated with hotels and resorts, and may be deadly and costly. Prevention keeps guests and employees healthy and there is a lot of time and effort needed. This is all to make sure and ensure legionella is not overly present in these systems. Hotel rooms, bars, swimming pools – the plumbing systems that run anywhere in a hotel need to be checked. They can for sure be rife with the risks that can come with this disease.
Very important: making sure you meet water safety design standards
Planning the design of any new construction project, be it a new build, extension or refurbishment is a complex process. It is also a vital process too in order to get the best results. It can take many months before the first hole is dug or the first brick is laid. While it’s vital to ensure every part of a new building project meets all latest building and engineering standards at the initial design stage, the water systems and ensuring they are safe to use is of particular interest to us here.
Controlling legionella in a construction project
Legionella bacteria occurs naturally in many water sources around us, such as rivers, lakes and other watercourses. It can also contaminate manmade water systems and can lead to Legionnaires’ disease, a serious, potentially fatal form of pneumonia. It’s important to remember that in the UK, the primary safety regulator the Health and Safety Executive (HSE) consider Legionellosis (Legionnaires’ disease) to be a preventable disease. It is only as preventable, like with any disease when the best practices are undertaken as to how and how well it is managed. Water systems really do need to run and be set up to the very best capacity possible.
In terms of water safety, one of the biggest considerations for architects, building services engineers, contractors and property managers is the control of Legionella bacteria. It’s water systems and plumbing needs to be set up in a way that Legionella cannot become something of any easy presence.
Conclusion and what you can do
Whilst legionella has the ability to colonise a manmade water system of any size or type, we often encounter situations where an old water system has fallen victim to raised levels of bacteria in the water. When this does occur this can be a significant cause for concern. Certainly, dead legs, disused or infrequently used taps, shower heads, and other water outlets can pose a significant health risk. So too, can older water tanks and pipework where the water may also pick up infection.
Overall, a building refurbishment or new construction project can avoid all these potential problems, since everything going into the build is brand new. And yes, that is the case. If the project is adequately designed, planned and executed, we can expect the water systems to be safe from the dangers of legionella and ready for use. Overall, legionella management will be here for some time to come as this is an issue still so present.
