Former Sewage Farms 2010

Map Description

Use of Sewage Farms since 1874

Osdorf Manor was bought by the city of Berlin in 1874 and used as the first sewage farm. The pressure pipeline and the Osdorf sewage farm were completed and put into operation in 1876. A total of 20 sewage farm districts and two smaller sites used for field treatment of sewage were put into operation (cf. Tab. 1). The maximum of about 12,500 ha of prepared area was reached around 1928.

There have been increasingly severe problems with sewage farms since the 1920’s. Agricultural yields were high at the beginning, but then dropped considerably. Too frequent treatment cycles caused soil surfaces to be muddied by sedimented effluent contents. This impaired the aeration balance. Imbalances in the nutrient balance and the increasing pollution of the soil led to yield reductions of crops. This “field exhaustion” was met by attempts to aerate the soil with regular soil processings and with structural improvement measures such as spreading lime and animal dung. But it became apparent that the yield capability of the soil could only be maintained by lowering the amounts of sewage water treated.

There was an intensification of agriculture after 1945. More and more land was consumed for the cultivation of root crops and cereals. Changing production cycles reduced the time available for treatment for these locations, so that less sewage water could be processed. An attempt was made to offset these losses in capacity by a more intensive use of the remaining grassland sites.

The East Berlin waterworks and sewage water system continued to use the majority of sewage farms after the Berlin Wall was built in 1961. The Berlin Waterworks (BWB) had continued to use part of the Karolinenhöhe sewage farm. A large portion of the southern sewage farms had been used by the city of Potsdam WAB since the 1960’s. Sewage water from West Berlin continued to be handled at sewage farms in East Berlin and vicinity (cf. Tab. 1) in spite of separate administrations. The enlargement of the Nord sewage treatment plant in Schönerlinde for the improvement of water quality of the Panke, the Tegeler Fließ and the Nordgraben was financially supported by West Berlin.

Tab. 1: Sewage farms according to period of operation, volume and origin of the discharged waste water, area and land cover

Sewage farms were largely retained into the 1960’s. Only smaller portions were removed from operation, for street construction or the erection and fortification of the former border strips. Closures of large portions of sewage farms ensued after the Berlin sewage water treatment plants were established. The size of fields in use at the Karolinenhöhe sewage farm was considerably reduced after the Ruhleben treatment plant commenced operations in 1963. The Falkenberg treatment plant began operations in 1969, and large sewage farm areas were discontinued at the Falkenberg, Malchow and Hellersdorf sites. A large portion of these areas was used for residential housing and commercial development. The Marienfelde facility began operation in 1974, and the Osdorf sewage farm was subsequently closed in 1976. The Münchehofe and Tasdorf sewage farms were closed in 1976, following the start of operation at the Münchehofe sewage treatment plant.

There was a rise in waste water amounts and an increased need for treatment in East Berlin in the middle of the 1970’s. The remaining sewage farms in East Berlin and surroundings were supplied with particularly large amounts of waste water. Intensive filtration areas were established, particularly in the northern sewage farms of Hobrechtsfelde, Mühlenbeck, Schönerlinde and Buch, and in the southern areas of Waßmannsdorf, Boddinsfelde and Deutsch-Wusterhausen.

The final decision to discontinue sewage farms was made at the end of the 1970’s. Prerequisites were met with the operational start of the Schönerlinde sewage treatment plant in 1986, and the enlargement of the Stahnsdorf treatment plant, built in 1931. The expansion of the Waßmannsdorf treatment plant at the end of the 1980’s allowed the closing of more sewage farms.

The sewage treatment plants mentioned above were frequently constructed on former sewage farm sites. Portions of these areas continue to be used in the waste water treatment process, especially for sludge storage and composting.

Studies of the pollution and nutrient situation of discontinued sewage farm soils started to be carried out at the beginning of the 1980’s (BBA 1982, Metz/ Herold 1991, Salt 1987). The studies found considerable heavy metal contamination in soils and food crops. These findings were the basis for prohibiting cultivation of vegetables at the Karolinenhöhe site in 1985. Studies of the southern and northeast sewage farms had similar consequences. Cultivation of foodstuffs was limited to feed plants or crops that accumulate contaminants at lower levels.

Use of Sewage Farms from the 1990s until their Complete Closure in 2010

About 1,250 ha of fields were used for sewage treatment in portions of the Karolinenhöhe, Sputendorf, Großbeeren, Deutsch-Wusterhausen and Wansdorf sewage farms until 1994. Much smaller amounts of sewage water were processed than in the 1970’s due to portions being removed from operation. Sewage water amounts in Sputendorf sank from the 1971 level of 21 mill. m³/year to a 3.2 mill. m³/year at the beginning of the 1990s. The same is true for the Großbeeren sewage farm. Sewage water amounts there fell from 25.0 to 3.2 mill m³/year at the beginning of the 1990s. The reunification of Germany returned operating rights for the remaining sewage farms to the (West) Berlin Water Works (BWB), with the exception of Wansdorf and Deutsch-Wusterhausen, and that part of the Karolinenhöhe sewage farm located in the State of Brandenburg.

Parts of the Sputendorf sewage farm received up to 30,000 m³ daily of mechanically-biologically purified waste water from the Stahnsdorf sewage treatment plant. The plan was to only discharge mechanically treated waste water whenever the Stahnsdorf plant was working to capacity. A sludge decantation facility was erected on a portion of the Sputendorf sewage farm used as a sludge storage area. Clarified sludge from the Stahnsdorf plant was to be dewatered by centrifuges. The resulting sewage water was then returned to the treatment plant.

Sewage water for the Großbeeren sewage farm was purified in sedimentation tanks there. The Wansdorf sewage farm mechanically purified with its own pre-purification facilities. Waste water brought to the Deutsch-Wusterhausen sewage farm was mechanically purified in the Königs-Wusterhausen sewage treatment plant.

The Berlin portion of the Karolinenhöhe sewage farm was used for percolation. About 0.9 mill. m³ of mechanically-biologically purified waste water from the Ruhleben plant was percolated in 1990, as well as another 1.7 mill. m³ of waste water mechanically purified in Karolinenhöhe. The most important goals were the continuing immobilisation of nutrients and contaminants accumulated in the soil and the recharge of groundwater. Only mechanically-biologically purified sewage water was discharged after technical improvements at the Ruhleben plant were completed. The area was also held in reserve as an emergency depot should any purification plant operation be interrupted.

By 1994, the Sputendorf, Großbeeren, Deutsch-Wusterhausen and Karolinenhöhe sewage farms had been completely closed down. The Wansdorf sewage farm was still in use until 1998. The elution studies involving the discharge of clear water by the Berliner Wasserbetriebe (BWB) on the areas of the Karolinenhöhe sewage farm were completed. After almost 135 years, the era of sewage farms in Berlin and its surrounding areas therefore came to an end in 2010.

A large portion of the Karolienhöhe sewage farm, which was defined as a “landscape conservation area” in 1987, serves as an example of subsequent and ecological use of former sewage farms. The purpose was to protect the diversity and character of the landscape, to restore and permanently maintain the efficiency of the natural balance, and to preserve an extensive recreation area (Karolinenhöhe Ordinance 1987, Berlin House of Representatives 2021).

Maximum Extent of the Former Sewage Farms and their Land Cover in 2018

The map and Table 1 show the maximum extent of the sewage farm districts for each period of operation.
Figure 3 and Table 1 illustrate the land cover in 2018, after all sewage farms had been closed down. For this purpose, the land cover data extracted from the “Corine Land Cover 5ha” data (© GeoBasis-DE / BKG (2018)) was grouped into six classes:

• Urbanised / built-up (clc18: 111, 112, 121, 122, 132, 133),
• Urban green space / sports area (clc18: 141, 142),
• Agriculture incl. meadows and pastures (clc18: 211, 231),
• Forest (clc18: 311, 312, 313),
• Natural green space (clc18: 321, 324, 411, 412),
• Body of water (clc18: 512) (Federal Agency for Cartography and Geodesy 2021).

Fig. 3: Land cover of the former sewage farm districts in 2018