Kuressaare advises residents to boil drinking water

ERR reports that preliminary tests found coli-like bacteria in drinking water samples from every sampling point in Kuressaare, with E. coli also detected at the end of the Upa pipeline and in raw water entering Unimäe. Saaremaa Municipality has advised residents to boil water before drinking it.

The samples were collected during routine testing on September 1. The results are preliminary laboratory information, and the official analysis report has not yet been issued.

Repeat samples will be collected immediately, while preventive chlorination and flushing of the water pipelines will begin. Kuressaare Veevärk, the local water utility, has informed the Health Board and agreed on further steps.

The municipality said that the widespread presence of coli-like bacteria pointed more likely to contamination of raw water from the water intake than to contamination within the distribution network. However, the cause will be difficult to assess before the repeat test results are available.

Coli-like bacteria are common environmental bacteria found, for example, in nutrient-rich water, sewage, soil and decaying plant material. Their presence does not generally cause illness, but as indicator organisms they can provide information about the condition of the drinking water distribution network.

The presence of individual coli-like bacteria mainly indicates a need to flush the pipelines. Adding chlorine to drinking water is one way to help ensure its cleanliness. The municipality said the health risk from isolated coli-like bacteria was unlikely, but stricter-than-usual measures were being applied to provide additional protection for vulnerable groups.

E. coli is a bacterial species that forms part of the natural microbiota of humans and animals. It can enter natural water and wells, particularly when organic material is carried from the ground by heavy rain or melting snow. Its presence is primarily a signal that drinking water requires further testing and that treatment may need to be adjusted. While most E. coli strains are harmless, some rare strains can cause illness, so every detection is treated seriously and immediate steps are taken to restore water quality.