According to the Federal Ministry for the Environment, the bacteria are found in the intestines of humans and animals and enter bodies of water with faecally contaminated wastewater. Detection indicates faecal contamination of the water. The high summer temperatures continue to lead to problems with algae in numerous bodies of water, according to the Lageso. The water quality of the Dahme is impaired in the areas of Schmöckwitz, Große Krampe and Bammelecke. The same applies to the Lower Havel in the areas of Grunewaldturm, Kleine Badewiese, Breitehorn, Lieper Bucht, Radfahrerwiese, Großes Fenster, Strandbad Wannsee and Alter Hof.