Drinking water often looks clear and smells inconspicuous, but can be microbiologically contaminated. This article explains when a microbiological test is useful and what it reveals.
Initial situation
Drinking water can be microbiologically contaminated despite its clear appearance and inconspicuous odor. This is particularly relevant for in-house water supplies, rarely used pipes, after construction work, after prolonged stagnation, in the event of abnormalities or in sensitive facilities.
Procedure
Depending on the issue, typical microbiological parameters are examined, for example Escherichia coli, enterococci, coliform bacteria and colony counts. E. coli and enterococci serve as indicator organisms for possible faecal contamination; such indicators can be used to assess whether a hygiene risk may exist.
Result
The test shows whether the drinking water is hygienically normal or whether there could be contamination, stagnation or a technical problem. The main benefit lies in early detection: causes can be narrowed down and targeted measures can be planned before a hygiene problem becomes a health risk.