Water quality assessment of Dewana and Darbandikhan reservoirs for drinking purposes

People living in Darbandikhan city have lacked access to basic drinking water services since many years. This research aimed to examine water quality of the Dewana and Darbandikhan Reservoirs in Darbandikhan city for drinking purposes, since there are no studies assessing both water reservoirs in this city. The samples were taken from various points in each of the reservoir with three replications each month during 2023. The evaluation of water quality depended on utilizing three indices which are: the water quality index (WQI), Heavy metal pollution index (HPI), and Metal pollution index (MI). The WQI index calculated using physicchemical parameters including (pH, turbidity, Electric conductivity, Ca2+, Mg2+, K+, Na+, HCO3-, SO42-, and Cl-). Also, the HPI and MI models calculated using several heavy metals (Co, Ni, Cr, Mn, Zn, Al, Fe, and Pb) which analyzed by using ICP. The obtained results of WQI for both reservoirs’ water found to be unsuitable for drinking purposes. Based on the HPI model, the results showed that water in Dewana Reservoir is proper for drinking, and the quality of water fall under the (Low polluted) class; while, the Darbandikhan Reservoir water is unsuitable for drinking purposes, and falls under the (High polluted) category. The scenario is the same for the MI model; all the water samples in Dewana Reservoir were of purified quality; however, all the water samples in Darbandikhan Reservoir were strongly affected by the heavy metals.