The portal wasseralarm.net provides information on this topic. Drinking water analysis stipulates that approximately 50 of up to 2,000 substances in drinking water must be tested for. Water suppliers comply with the drinking water limits in most cases. When contamination is discovered, drinking water warnings are issued immediately – almost daily, as these reports show. UNESCO has penalized Germany, the EU has threatened legal action, and the EU and WHO are calling for lower limits. For example, hormone-like substances, drug residues, and pharmaceutical residues are not tested for in drinking water analysis, so exceedances cannot be detected. A few PFAS substances were only recently added to the list. Reports on this can be found here: Important reasons to filter your water.