assessment of chemical quality of drinking water in rural area of qorveh city, kurdistan province, iran

Groundwater aquifers as one of the main sources of water supplies are faced with different risks such as level dropping due to lack of precipitation, and natural and non-natural pollutants. thus, it is extremely necessary to monitor ground water quality. in the present study, the concentration of cations, anions, and some toxic metals was evaluated in 21 rural water supplies in qorveh plain in two stages. data were analyzed with rockwork and arc gis software. results from hydro chemical analysis showed that all the studied parameters had lower concentrations than the permitted limits, except for arsenic (as) and selenium (se) in some of water resources. as concentration in 20% of studied resources were higher than recommended standards. there was a significant difference between nitrate (no3−) concentrations in the two low- and high-water seasons (p < 0.01). bicarbonate (hco3^−) and calcium (ca2^+) were the prevalent anion and cation, respectively, meaning that samples type was calcium-bicarbonate. wilcox diagram classified the samples in c2-s1 and c3-s1 classes. correlation coefficient between chemical parameters showed that hco3− and ca2+ had the highest correlation. finally, it can be said that except for as and se, other water characteristics have a good quality for drinking water application. however, current and uncontrolled application of the studied water supplies, especially in agricultural activities, can change and decrease their quality. therefore, it is important to prevent the health threats of such process.