A guide for hospitals, nursing homes, schools and universities, hotels, public and commercial buildings that were closed.

One of the consequences of the covid19 pandemic has been the closure or slowdown of the activities of many businesses and public institutions, such as kindergartens, schools, universities, hotels, holiday homes, nursing homes and other commercial and public buildings. It causes, as a secondary effect, that the frequency of use of the water system is less intense and that the water can stagnate in the pipes, if there are no specific rinsing systems or automatic opening of the flow. This can lead to the proliferation of bacteria that are highly harmful to our health, including legionella. This bacterium grows in stagnant water between 20°C and 45°C. When we inhale the steam containing the pathogen, it enters our body and can cause aggressive, often fatal, pneumonia with high fever and symptoms similar to those of the flu and the covid19. Legionella infection can make a parallel or subsequent coronavirus infection worse, since it causes significant damage to the lungs and a dangerous weakening of the whole organism. Seniors and people with low immune systems are particularly at risk of legionella infection, the same risk groups as covid19!

Preventive Measures

After and during the “lock down”, precautions are crucial to avoid the risk of a Legionnaires Disease Outbreak, which is considered very dangerous by international medical associations. The first and most important preventive measure is that drinking water must be and stay “fresh.” All withdrawal points must be used regularly so that the water does not stagnate in the pipes. A frequent flow of water, preferably daily, is essential for this. To define the recommended actions to apply, we need to distinguish two scenarios: buildings with automatic washing devices of the drinking water system and those without automatic devices.

Water systems with automatic washing devices

They are equipped with systems that automatically make the water circulate even when the system is not used. An example of these automatic solutions are our electronic taps, which supply every 24h after the last use a volume of water that guarantees its “freshness”! After the time the water system is closed and in particular after the covid19 lock down, the ideal solution is the use of infrared and automatic rinse taps, which prevent water from stagnating and pathogens from growing. For buildings that have these automatic systems, we simply recommend reprogramming the electronic taps with the aim of increasing the rinsing frequency and duration. Our 54512 and 54510 infrared taps, for example, can be easily set up with a remote control.

Water systems without automatic washing devices

If the system do not have these automatic devices, the rinsing must be simulated manually during the closing time, especially before the reopening, requiring an important maintenance and control effort. Indeed, special rinsing plans must be provided to ensure the regular use of all taps and other shut-off points (showers, toilets …) in the building or apartment. The drinking water system must be purged before its washing, disinfection and startup. For this purpose, the shut-off points must be completely open, starting from the point furthest from the water exit point. The washing is carried out in sections, starting from the main valve up to the farthest extraction point. After the rinsing time, which duration depends on the size of the system, the withdrawal points are closed one after the other starting from the last one that was opened. After putting the system in service, the operator must ensure that the water is regularly used at all the shut-off points and that there is no stagnation. We also recommend to rinse all the building shut-off points on the same day. A high simultaneous withdrawal speed promotes the flow and change of water in existing pipes and tanks. The mixers must be completely purged on both the cold and hot water system. If this manual simulated operation takes place for an extended period of time, the water heating system must be closed to avoid wasting energy, but the circulation pump should continue to operate. In the event that the heating system was closed before the lockdown, the entire hot water and circulation system must be turned on and then purged. The heated water must first be discharged through a sufficient withdrawal from the pipes and, if possible, from the drinking water tank, then the hot water system must be washed as well as the cold water system.

By Juergen Schweitzer

Head of Operations