According to city council candidate Volker Reeh, the capacity of the sewage treatment plant in Wolfratshausen is not infinite - and an expansion is hardly possible.
Geretsried / Weidach - Volker Reeh has been a member of the Isar-Loisach Group wastewater association for 24 years. The second chairman knows how increasing population numbers or the settlement of new businesses affect the wastewater treatment plant in Weidach. He recently led some interested visitors together with the managing director of the plant, Lorenz Demmel, over the Isarspitz site in Wolfratshausen-Weidach. It was a slightly different campaign event. Reeh is still in the Geretsried city council for the CSU and is now running on the Geretsried list.
Half of the wastewater comes from industry
The wastewater treatment plant cleans the wastewater from the six municipalities of Wolfratshausen, Geretsried, Egling, Icking, Dietramszell and Königsdorf. The catchment area holds a total of 120,000 so-called population values. Half of the wastewater comes from industry. The plant in Weidach is one of the largest in Bavaria, it belongs to category 5. Because the state capital Munich wants bathing water quality for the Isar into which the purified water is fed, a lot of money has been invested in the Weidacher plant in recent years, most recently around 1.2 million euros in a new gas boiler.
Handkerchiefs belong in the trash can
The tour started on a container with a bad smell. This is where the solids are stored, such as toilet paper, which are removed from the water with a rake that arrives in Weidach through the widespread sewer network. "Nothing else should get into the toilet than toilet paper," warned Lorenz Demmel. On the other hand, wet wipes soaked in oil, ear sticks or even the new handkerchiefs that do not dissolve should definitely be placed in the waste bin.
The sorted and dried screenings are regularly brought to the landfill. The remaining water-sludge mixture continues to flow into a clarifier. The primary sludge is formed there by sedimentation. Air is added to the wastewater in the two “activation tanks”, which can be clearly seen in the bubbling. Nobody would think of bathing in the brown broth. It wouldn't work at all. "You would drown in this pool because the water no longer carries you due to the high oxygen content," explained Volker Reeh. Carbon, nitrogen and the unwanted phosphorus are eliminated here by complicated biological-chemical processes. This is followed by a basin in which the sand is filtered out, a secondary clarifier and a UV system. "Over 15 years ago, we were one of the first wastewater associations to install a UV system for final cleaning," reported Reeh.
Residual sludge is burned
The remaining sludge should no longer be applied to the fields. It was transported away and burned. Around 50 percent of the electricity required is produced in an in-house cogeneration plant. In the laboratory in the administration building, chemists constantly check the water for its bacterial content. In the past, there was even a fish pond on the site of the sewage treatment plant, in which "test carp" were kept in the clarified water. "Although they were not eaten, their good prosperity and long life were seen as a sign of high water quality," said Reeh.
Read also: Local election 2020: Geretsried list runs without mayor candidates
The candidate on the Geretsried list raised concerns that the capacity of the Weidach facility was not infinite. Because it borders on a nature reserve, expansion is hardly possible. "We have planned ahead in the association by 2029 and see no problems until then," said the vice chairman. But if Geretsried continues to grow so strongly and if other businesses settle down, the plant will reach its limits. According to Reeh, the city can make new commercial enterprises require that they purify their wastewater. It's only fair, he thinks.
Tanja Lühr
Also interesting: How the Americans created today's Geretsried