Two million people. That’s how many people the Klärwerk Gut Großlappen cleans the wastewater for every day. Can you imagine the sheer volume of water that flows through this incredible facility?
Welcome to the Klärwerk Gut Großlappen a vital part of Munich’s infrastructure. Since 1926 this wastewater treatment plant has worked tirelessly to keep the Isar River clean. It’s a testament to Munich’s commitment to environmental protection. It is located in the Freimann district on the Fröttmaninger Berg between the A9 motorway and Freisinger Landstraße.
Before its construction the Isar River suffered badly from pollution. The growing city’s expanding sewage system overwhelmed the river’s capacity. In 1912 the government of Upper Bavaria demanded the construction of a sewage treatment plant. This would require connecting 60 percent of Munich’s households to the public sewage network. Munich city council toured other cities inspecting their wastewater treatment facilities. A pilot plant was built. Then World War One intervened delaying plans.
The project was revived when the city wanted to use the Isar River water for power generation. The construction of the Oberföhringer weir and the diversion of most Isar water made a treatment plant essential. Construction of a mechanical treatment plant and a biological fish pond system at the Ismaning reservoir near Großlappen was needed. This phase lasted from 1922 to 1926. Initially the mechanical cleaning used coarse sieves and then two-part digestion tanks called Emscher tanks. These were in operation until 1989. The extracted sludge was transported by a small railway to fields up to ten kilometers north of the plant. These fields belonged to the Garching farmers’ cooperative and the municipal agricultural estate Großlappen.
Increasing environmental awareness heightened demands on the plant’s performance. Further expansion followed. In 1960 a second inflow with mechanical cleaning facilities was added. The biological treatment stage was completed in 1973. In 1994 a second biological stage for nitrogen removal was added. Expansion was limited by the surrounding area which had grown denser over the decades with settlements streets and the northern Müllberg landfill. New facilities often replaced older ones. This led to the construction of a second sewage treatment plant in the 1980s: Gut Marienhof.
Klärwerk Gut Großlappen continues to evolve. Today it is one of the most modern and energy-efficient plants in Europe. The sludge from wastewater treatment generates biogas powering much of the plant’s energy needs. It’s a fascinating blend of history technology and a crucial role in Munich’s environmental stewardship. A true marvel of engineering right before your eyes.