Pathogenic bacteria are a major health concern in drinking and bathing waters. Present day assessments of bacterial contaminations rely on culture methods, i.e. Plate counts of oviform bacteria, despite low reliability for detection of bacteria and their pathogen city. It is our objective to develop) molecular methods to identify and quantify pathogenic bacteria directly in any given water sample and to assess their state of activity. We will combine quantitative PCR and DNA-chip technology to retrieve specific gene sequences and assess their amounts in water samples. 16S renal sequences serve to identify species, mina of tuff genes and 16S reran indicate bacterial activity, pathogen city factors assess infectious risks. The applicability will be tested in relevant aquatic environments of the EU. The final objective is to create a novel technology for the EU-wide detection of waterborne pathogenic bacteria and to validate its mass application.