This paper presents monitoring results of chlorinated drinking water content of volatile (tri-halomethanes) and non-volatile (halo acetic acid) organochlorine compounds from various water plants in Ukraine with the traditional water treatment technology of Dnipro water, that differs only in using different chlorinated water disinfection agents. The analysis and hygienic evaluation of the re-cent years data, regarding drinking water contamination with toxic organochlorine compounds, has been conducted. Among the both classes of organochlorine compounds we identified the priority sub-stances and the main factors affecting their formation. We marked the formation of abnormal trihal-omethanes levels, in contrast to the halo acetic acid, when used the chlorine gas in water treatment. Its replacement for chlorination of preamonization on specific water treatment plants led to the mini-mization of trihalomethanes formation and flow into the drinking water to safe levels.