Regulation of concentration of chemical substances including hazardous ones-a scientific challenge

The paper presents a commented comparison of different standard limits for chemical substances including the priority/priority hazardous substances in order to protect the good and very good quality of drinking water as the Water Frame Directive requires for preserving population health and safety. A short review of the regulation efforts is presented underlying the scientific evidences behind keeping those standards updated with the latest research in the field. Example of Romanian legislation requirements for keeping under control the water bodies’ discharges of priority/priority hazardous substances and comments related to the necessity of a mature judgment in applying it are presented in conjunction with the European and international practices.