Zdravstveno ispravna voda za ljudsku potrošnju mora biti kemijski i mikrobiološki ispravna te dobrih senzorskih svojstava. Dezinfekcija je najvažnija faza u pripremi vode za piće, a najčešće upotrebljavano dezinfekcijsko sredstvo je klor. Tijekom kloriranja, klor može reagirati s prisutnim organskim tvarima stvarajući pritom čitav niz nusprodukata dezinfekcije među kojima su i trihalometani. Trihalometani su lako hlapljivi halogenirani ugljikovodici koji imaju negativno djelovanje na centralni živčani sustav, jetru i bubrege. Koncentracije triklormetana (kloroforma) CHCl3, bromdiklormetana CHBrCl2, dibromklormetana CHBr2Cl i bromoforma CHBr3 te ukupnih trihalometana određena je u uzorcima vode s vodocrpilišta Bartolovec u Varaždinskoj županiji metodom plinske kromatografije u za vremensko prazdoblje od 2016. do 2019. godine. Rezultati analize pokazali su da u promatranom periodu koncentracije trihalometana nisu bile iznad dozvoljene vrijednosti od 100 μg/L te da je voda zdravstveno ispravna i udovoljava svim važećim propisima..; Health safety of water intended for human consumption means that water has to be chemically and microbiologically adequate and have good sensory properties. Disinfection is the most important phase in the preparation of water for drinking purposes, and the most frequently used disinfectant is chlorine. In the process of chlorination, chlorine may react with present organic matter and form a number of disinfection by-products, one of which are trihalomethanes. Trihalomethanes are highly volatile halogenated hydrocarbons that have adverse impact on the central nervous system, liver and kidneys. The concentrations of trichloromethane (chloroform) CHCl3, bromodichloromethane CHBrCl2, chlorodibromomethane CHBr2Cl, bromoform CHBr3 and total trihalomethanes were determined on water samples from the water abstraction site Bartolovec in the Varaždin County for the 2016-2019 period by using gas chromatography. The analysis results showed that the trihalomethane concentrations in the observed period were not above the permissible value of 100 μg/L, i.e. that water was safe for human consumption and met all applicable regulations..