This paper presents an analysis of the quality of groundwater that are exploited in the territory of the Mesic village in the factory "Moja voda" on the slopes of the Vrsac Mountains. Spring waters formed in the Tertiary and Quaternary sediments are situated near the high-grade metamorphic complex border of Vrsac Mountains that represents the northernmost prolongation of Serbo-macedonian massif to the West and low-grade metamorphic complex of the Ranovac-Vlasina-Osogovo terrane to the East. Groundwater is assigned on the basis of chemical analyses to the group of hydrocarbonate-calcium-magnesium non-carbonated low-mineral water, whose physical properties and chemical composition is the consequence of geological conditions of the environment through which circulates. The dominant anions and cations (HCO3 -, Ca2 + and Mg2 +) accumulate in groundwater of Mesic as a product of weathering of silicate minerals present in igneous and metamorphic complex of Vrsac Mountains. The specificity of these waters is an adequate amount of selenium in its composition related to the Tertiary and Quaternary clay deposits which have the pyrite and organic matter, as well as silica, whose presence in the water is a consequence of weathering (hydrolysis) of silicate minerals, particularly feldspar. Water from the exploration wells is classified as ?B reserve? according to the applicable criteria. [Projekat Ministarstva nauke Republike Srbije, br. 176017]