Health warning: Bacteria in Teufelssee, algae in Unterhavel

The State Office for Health and Social Affairs (Lageso) has issued a health warning for Berlin's Teufelssee lake in the Grunewald forest due to a high level of E. coli bacteria.

Swimming in the Unterhavel is also still not recommended, the Lageso continued. There are problems with algae there. The areas affected are Grunewaldturm, Kleine Badewiese, Breitehorn, Lieper Bucht, Radfahrerwiese, Große Steinlanke, Strandbad Wannsee and Alter Hof. There is a pronounced algae bloom with streaks and carpet formation.

Mass algae growth on the Dahme too

On the River Dahme, the depth of view in the areas of Schmöckwitz, Große Krampe and Bammelecke is considerably restricted due to the growth of masses of algae. In general, the state office warned against swimming in murky waters. Children in particular should avoid areas with green and blue-green streaks (cyanobacteria). Sensitive people could experience skin irritation and allergic reactions.

E. coli bacteria indicate fecal contamination

E. coli bacteria are found in the intestines of humans and animals. Detection indicates fecal contamination of the water. According to the Federal Environment Agency, this occurs when wastewater, rainwater overflows or run-off from agricultural land flows into the water. Bathers themselves or birds could also contribute to faecal contamination locally. Teufelssee covers an area of 2.4 hectares. It is embedded in Berlin's Grunewald forest.