study of the waters of the east of gonbad-kaboos ( minoodasht)

minoodasht which is located 18 km. far from the east of gonbad-kaboos, is one of the most important agricultural areas of iran. a great development in the agriculture of this area has been achieved by drilling wells, building canals, constructing the dams and also irrigation of the farms by pump. for determination of the physical and chemical characteristics of the waters from different sources which are a valuable in minoodasht area 12 different samples of water were analysed. the results of analysis are given here. in general most of the samples were neutral or slightly acid, calcium and bicarbonate ions were the predominant ions of the different samples. the waters of minoodasht area, are calcium bicarbonate type, which leave high residue after evaporation and have high electrical conductivity. the amount of the nitrate ion present in most of the samples were found to be higher than the level permitted for drinking water, the presence of a large amount of nitrate ion in the water supplies of minoodasht, and the effect of nitrate ion on human health, makes the water of this area undesirable for drinking. since phosphate and nitrate fertilizers are largely being used in minoodasht, nitrate ion seems to be released in large quantities into rivers and streams, and as a result penetrates into the underground water sources.