Impact of COVID-19 on drinking water hygiene

The COVID-19 pandemic has forced the closure of many public institutions and businesses, as well as the temporary shutdown of production sites or, at the very least, a significant reduction in employee activity. The slowdown in activity has direct consequences on hygiene in drinking water facilities. Such a situation can lead to water stagnation and therefore a risk of germ proliferation. Operators must do everything possible to ensure the proper use of drinking water facilities by taking appropriate measures. The challenge is significant: protecting drinking water from microbial loads and avoiding very high associated costs.

If the containment measures involve an administrative closure of the building, the operator of the drinking water installation must nevertheless ensure compliant operation. In particular, it is essential to open all water points at least every three days, manually or automatically, in order to carry out a complete exchange of the water present in the pipes. In the event of a longer interruption of use, the operator must comply to the decree of November 30, 2005, amending the decree of June 23, 1978 relating to fixed installations intended for heating and supplying domestic hot water to residential buildings, work premises or premises open to the public. DGS Circular No. 98-771 of December 31, 1998, on public health, also reiterates the need to implement good practices for maintaining water networks. In particular, it recommends assessing the quality of maintenance by screening for Legionella bacteria.

Immediate implementation of a flushing plan

Even a temporary shutdown of the drinking water system can result in significant costs when restarting the system: rinsing, disinfection, or even sampling. Depending on the age of the system, the restart process can also lead to a failure of the entire drinking water system in the building, requiring high renovation costs. 

Implementing a proper flushing plan prevents operators from having to perform long-term flushing interruptions. Trained technicians can manually maintain proper operation of the drinking water system. The only requirement is to provide detailed documentation of the procedure. 

Maintain hot water production

It is also not advisable to shut down hot water production, even if the prospect of saving energy during the company closure is tempting. Drinking water tanks, for example, contain large quantities of stagnant water, which cannot be satisfactorily exchanged with simple flushing measures. Shutting down the systems no longer allows the operating temperature of 60°C required by thedecree of November 30, 2005 relating to fixed installations intended for heating and supplying domestic hot water to residential buildings, work premises or premises open to the public. At low temperatures, the risk of Legionella growth is real. Maintaining hot water production is therefore significantly more economical and hygienic than the random effect of short-term energy savings.