Physical, chemical, and microbial quality of drinking water in Sanandaj, Iran

Drinkability of water is determined based on its physical, chemical, and microbial properties. Undesirable changes in these parameters could threaten the health of consumers. The present study aimed to assess the physical, chemical, and microbial parameters of the drinking water sources in Sanandaj, Iran and compare them with the national standard values. This descriptive, cross-sectional study was conducted for 24 months. Samples were collected via simple random sampling from 116 stations in accordance with the principles of water sampling, including 51 stations of Sanandaj water distribution system, 15 reservoir stations, 25 stations for the outlet of the water treatment plant, and 25 stations for raw water. In total, 2,784 samples were obtained from the stations and transferred to the laboratory in standard conditions. Residual chlorine, pH parameters, turbidity, total coliforms, thermophilic coliforms, and heterotrophic plate count (HPC) were measured. Data analysis was performed in SPSS version 18 using t-test and ANOVA. According to the results, the mean values for the physical parameters of turbidity and pH in the water distribution system were 0.9522 NTU and 7.9644, respectively. With regard to the chemical parameters, the mean residual chlorine in the water distribution system was 0.5548 mg/L, and the microbial parameters of total coliforms, thermophilic coliforms, and HPC were 0 MPN/100 mL, 0 MPN/100 mL, and 107.6533 CFU/ml, respectively. Our findings indicated that the mean concentrations of the measured parameters in the water distribution system of Sanandaj were within the national standard limits.