a survey of chemical quality of rural drinking water of birjand and qaen plains, iran

background: during recent years, overpopulation, increase of wastewater, and drop in water tables has led to high concentration of salts in underground water, which is an important environmental pollutant. if concentration of salt in drinking water exceeds the limits, it will be dangerous for health. the aim of this study was to measure physical and chemical parameters in drinking water of rural areas of birjand and qaen plains, iran, and compare them with national and international standards. methods: this was a cross sectional descriptive study carried out during the autumn of 2009 and the spring of 2010. 54 samples from 27 stations (27 samples in spring and 27 samples in autumn) were randomly collected and the concentrations of their physical and chemical parameters were measured. the results were analyzed by descriptive statistical method and shuler’s diagram. findings: the results showed that the remaining dry solids (37%), hardness (25%), sulfate (33%), sodium (70%), chloride (25%), and electrical conductivity (%51) in all samples, were more than national standards. fluoride concentration in 92% of analyzed samples was less than the minimum recommended level. according to shuler’s diagram, the parameters of water quality ranged between good and poor situations. conclusion: since the recent drought has negative impacts on water quality of rural areas, and the measured parameters have not met the standards, it is necessary to consider a continuous plan for monitoring of water resources.