Verdunstungskühlanlagen, Kühltürme und Nassabscheider werden in Zukunft besser überwacht
In future, evaporative cooling plants, cooling towers and wet scrubbers will be monitored better
Wherever warm water is stored, legionella are lurking—be it in water pipes, air-conditioning systems or swimming pools. It only takes a few of those bacteria to cause a serious bout of pneumonia. The Robert Koch institute estimates the number of new cases in Germany at approximately 6,000 to 10,000 per year. CAPNETZ’ (competence network for Community-Acquired Pneumonia) projections go even further, stating 15,000 to 30,000 cases annually of pneumonia not acquired in hospitals, meaning that 4% of pneumonia cases in Germany, that were not acquired in hospitals, are caused by legionella infections. The mortality rate is estimated at up to 10%, so we have to assume around 3,000 fatalities per year. This is almost the same as the number of road fatalities per year in Germany.
German cabinet adopts new legionella ordinance
The German cabinet approved a new legionella ordinance on 23 March 2017 to minimise the risk of legionella outbreaks such as recent ones in Bremen and Warstein. According to the 42nd BImSchV, evaporative cooling plants, cooling towers and wet scrubbers are now to be better monitored, with the ordinance being largely based on the VDI 2047 Sheet 2 standard. The ordinance is to be adopted by the Federal Council on 12 May 2017 and to be in force as early as four weeks later.
Duty to notify of new and existing plants
According to the drafted 42nd BImSchV, there are now concrete specifications for hygienically sound operation of evaporative cooling plants, cooling towers and wet scrubbers.
Among others, the ordinance stipulates a duty to notify of new and existing plants. In case of a legionella outbreak, this helps local authorities to locate the discharge place faster and more effectively. This is immensely important, because in an emergency, every second counts. Here, containment takes precedence over causal research and liability issues. Requesting plant operators to use biocides is only possible if the outbreak sources can be identified quickly.
A practically ever present danger
Water is used for cooling in many technical processes, such as data centres or food production. The number of evaporative cooling systems needed for this is an estimated 50,000 in Germany. They harbour the risk of becoming the source of legionella infections. The circulating water has an ideal temperature for these bacteria to propagate and, due to its contact with the atmosphere, offers them an abundance of material to feed on.
The dangers and harmful effects of legionella are described in the VDI 2047 standard and, in an extended version, in VDI 4250 Sheet 2. The VDI are already working on a standard for outbreak management.