Hydrochemical characteristics of the groundwaters in Prilep’s part of Pelagonia valley– Republic of Macedonia

Hydrochemical properties of the groundwaters in Prilep region within the Pelagonia valley are analyzed with 12 samples of groundwater, taken from wells that exploits. The sampling was made only once on 27.08.2013. The groundwaters are used by the locals of this region as technical water, for irrigation of the surrounding arable land and for industrial needs. Wells of were taken samples of groundwater is separated into three groups: wells with free level with depth up to 10 m, wells with free level with depth up to 100 m and artesian wells. The graphical methods, Piper diagram and Chadha’s diagram, were applied in order to determine the hydrochemical properties of the groundwater. The results indicate that the groundwater samples have different hydrochemical properties. Ca 2+ > Na+>Mg2+ for the cations and HCO3 -> Cl- >SO4 2- for the anions were dominantly dissolved ions in the majority of the water samples. Generally, increased values of Ca2+, Mg2+, Na+, K+, HCO3- , K+ and Cl- occur in the groundwater from deeper artesian wells, as a result of the longer retention time of water in the underground and its interaction with the geological environment. Dominant groundwater in Prilep field, in all three types of wells, are waters from hydrocarbonate class (HCO3¯), calcium group (Ca), the first type of water. Groundwater from the shallow wells show the increasing content of K+, NO3 - and PO4 3- which indicates water pollution from fertilization of the cultivated areas, livestock farms as well as communal wastewater