FORMATION OF TRIHALOMETHANES AND BROMATE DURING 
DISINFECTION OF DRINKING WATER IN WATER TREATMENT 
PLANTS AND DISTRIBUTION SYSTEMS.

D. Ristoiu1, Urs von Gunten2, Iovanca Haiduc1, Monica Culea3, O. Cozar3C. Cosma1,

1University Babes-Bolyai, Faculty of Environmental Science, Str. M. Kogalniceanu nr.4, 400084, tel. +4 0264 405316, Cluj-Napoca, Romania, 
2EAWAG, Swiss Federal Institute for Environmental Science and Technology 
3University Babes-Bolyai, Faculty of Physics, Str. M. Kogalniceanu nr.1, 400084, tel. +4 0264 405300, Cluj-Napoca, Romania, 

	More than 500 disinfection by-products (DBPs) have been reported in the literature for the major disinfectants currently used (chlorine, ozone, chlorine dioxide, chloramines), as well as their combinations. Of these reported DBPs, only a small percentage has been quantified in drinking waters. Thus, there is significant uncertainty over the identity and levels of DBPs that people are actually exposed to in their drinking water. To determine whether the other DBPs pose an adverse health risk, more comprehensive quantitative occurrence and toxicity data are needed. The reaction of chlorine with Natural Organic Materials (NOM) existing in surface water leads to the formation of halogenated Disinfection By- Products (DBPs) including trihalomethanes, haloacetic acids, haloaldehydes, haloketones, haloacetonitriles, chloropicrin, and chlorophenols. The ‘high priority’ DBPs include brominated, chlorinated, and iodinated species of halomethanes, brominated and chlorinated forms of haloacetonitriles, haloketones, haloacids, and halonitromethanes. 
	Trihalomethanes (THM) are a byproduct of water chlorination, arising from the reaction between natural organic matter (NOM) in the source water and chlorine used for disinfection. There are four primary species of THM: Chloroform (CHCl3), bromodichloromethane (CHBrCl2), dibromochloromethane (CHBr2Cl), and bromoform (CHBr3). The speciation of the THM depends on raw water quality and treatment characteristics. According to EPA, these three substances belong to carcinogens and Priority Toxic Pollutants. Bromoform, chloroform and dibromochloromethane belong to the category of Hazardous Wastes. Dibromochloromethane has shown positive results for mutagenesis in Salmonella typhimurium. Parametric values for THMs, based on the additional lifetime cancer risk 1/1000000, have been set by the European Commission in the COM (94) 612 Council Directive, adopted in 1995. The Council of the European Community has established a maximum contaminant level of 0.100 mg/L for the total THM due to increased evidence of adverse health effects linked to these compounds (Council Directive 98/83/EC). 
	The paper will give an overview over drinking water quality with regard to disinfection and disinfection/oxidation by-products in Transylvania as an indicator for the situation in Romania and will describes the next steps in Romania’s plans to implement a system of integrated water management, with particular attention focused on the tasks that will be undertaken to develop and demonstrate THMs analysis methods in the WAQUA component of a project, started in 2005 with full support from Swiss National Science Foundation.