After November had started with a lot of rain, all soils were soaked and soggy. When it snowed heavily from 12th to 13th September deep into the valleys, the roots of many trees could no longer withstand the weight of the snow and fell down in rows. This led to catastrophic situations in the entire Pustertal valley: not only the entire traffic came to a standstill due to the many interrupted roads, but also the power supply in the Pustertal area collapsed completely. A 'Black Out' was the result.
The power supply is vital for a sewage treatment plant. Without a functioning power supply it is not possible to maintain the purification process, which would result in untreated wastewater entering our rivers. Not only that: if the aeration in the biology fails, there is a danger that the biocinous organisms, i.e. those that biologically purify the wastewater, will be damaged and in the worst case even die. In this case a sewage treatment plant needs several weeks until these bacteria recover and the plant reaches its full purification capacity again.
The employees on duty at the sewage treatment plants had their hands full to cope with the many incidents and stayed on the plants for days and nights. The large amount of snow alone would not be the problem. The sewage treatment plants are equipped with emergency power plants in case of emergency. However, the emergency power operation is not designed to bridge power outages lasting several days. In emergency operation, not all system components are supplied in order to make do with the remaining reserves for as long as possible.
The Tobl and Welsberg plants were hit particularly hard. They had no electricity for days and were only able to maintain operation to a limited extent. The drying and incineration plant in Tobl failed for several days.
The employees of ARA Pustertal AG sometimes took on great risks in order to reach the plants at all. In this extreme case, operating conditions were not completely harmless in order to prevent major damage to the environment and the plants.
Only with motivated and well-trained employees can it be possible to face such exceptional circumstances and master them successfully.
ARA Pustertal AG also succeeds in this.