If necessary, performing intervention should be minimised and only used as a last resort to ensure a high drinking water quality. Particular attention must be paid to an overall consideration of the drinking water installation. Particularly in existing buildings, care must be taken to ensure that the preventive measures, at least in the cellar distribution and in the risers, are implemented before the intervention measures.
Step 3: Intervention
If high germ count or pathogens are detected by drinking water sampling, this is usually due to a neglect of the preventive measures. In addition, there is an "improper operation" of the drinking water installation over longer periods of time.