Organohalogenated compounds levels in chlorinated drinking waters and current compliance with quality standards throughout the European Union

The effects of chlorination on the formation of organohalogenated compounds in drinking waters from both treated surface and ground waters have been investigated. In this extensive study, the levels of these chemicals found at the outlets of major waterworks and the increment due to disinfection treatments have been evaluated. Thus, current drinking water standards and the compliance for utilities throughout the European Union have been analysed. The results showed that the most abundant organohalogenated compounds present in treated drinking waters were trihalomethanes with noticeable higher levels associated to treated surface waters. The range of concentrations for these chemicals was explained by the different treatment conditions. However, the study determined that current levels of organohalogenated compounds in chlorinated drinking waters are actually below established guideline values. Furthermore, a decrease in the concentrations of the organohalogenated compounds formed during the chlorination stage is noticeable. Optimization of the treatment processes, water resource protection and control of drinking water distribution seems to be the best preventive approach to reduce organohalogenated compounds formation.