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 i nvestigated. In this extensive study, the levels of these chemicals found a t the outlets of major waterworks and the increment due to disinfection tre atments 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 pres ent in treated drinking waters were trihalomethanes with noticeable higher levels associated to treated surface waters. The range of concentrations fo r these chemicals was explained by the different treatment conditions. Howe ver, the study determined that current levels of organohalogenated compound s in chlorinated drinking waters are actually below established guideline v alues. Furthermore. a decrease in the concentrations of the organohalogenat ed compounds formed during the chlorination stage is noticeable. Optimizati on of the treatment processes, water resource protection and control of dri nking water distribution seems to be the best preventive approach to reduce organohalogenated compounds formation. (C) 2000 Elsevier Science Ltd. All rights reserved.