Health Dyes to clarify cause of drinking water contamination in Uster

Because the cause of the drinking water contamination in Uster in August is still unclear, those responsible are now flushing the Strandbad groundwater pumping station with dye. As a result, Lake Greifensee could become discolored from Tuesday until the end of October.

The dye is harmless to humans and animals, Energie Uster AG, which is responsible for the drinking water supply, wrote on Monday. The Strandbad groundwater pumping station, where the contamination originated, is still disconnected from the network.

In mid-August, contamination with E. coli bacteria was detected in the drinking water of the neighborhoods south of the railroad line. The population was advised to only use the water after boiling it first. Since August 12, the water has been safe to drink again. However, the cause of the problem has not yet been discovered.

Colors should find their origin

According to Energie Uster AG, the dyeing tests are now being carried out to determine the source of the contamination. The groundwater extracted during the flushing process will be discharged directly into Lake Greifensee. This has been approved by the relevant authorities. In addition, technical experts will accompany the flushing.