Original scientific paper HYDROCHEMICAL DATA FOR THE GROUND WATERS IN THE BITOLA’S PART OF THE PELAGONIA VALLEY, REPUBLIC OF MACEDONIA

A b s t r a c t: For determination of some hydrochemical data in the ground waters of the Bitola part of the Pelagonia valley, are taken single samples from 19 wells. Specified values for pH indicate that the waters belong to the group of slightly alkaline ground water (pH = 7.2 – 8.9). Following to the classification of Alekin the majority of tested water according the content of the anion fall into hydrocarbonate class, calcite group and a smaller number in the chloride and sulfate class, sodium and magnesium group. Increased values of TDS, Ca2+, Mg2+, Na+, K+, HCO3-, Cl – and NH4+ occurs in the ground water from deeper artesian and subartesian wells, as a result of the longer retention time of water in the underground and its interaction with the geological environment. Ground water from the shallow wells occurs the increasing content of PO43 – and NO3 – which indicates water pollution from fertilization of the culti-vated areas, livestock farms as well as communal waste water. Knowing the hydrochemical feature of the ground wa-ter from the research area is from particular importance, because the water from these wells 5s used by the inhabitants of the region as industrial water, water for irrigation, packaging of mineral water and the exploitation of CO2. Key words: ground water; wells; Pelagonia valley; cations; anions; hydrohemical characteristic