Assessment of physical and microbial contamination of drinking water in Sanandaj villages

Access to safe drinking water is critical for public health, yet rural areas often face contamination challenges. This study aimed to assess the physical and microbial quality of drinking water in ۱۰ villages of Sanandaj city, Iran, to identify contamination risks and inform water management strategies. A stratified random sampling approach was used to collect ۴۰۰ water samples (۱۰۰ per quarterly round) from source, storage, and distribution points across wells, springs, and piped systems over ۱۲ months. Samples were analyzed for pH, turbidity, residual chlorine, total coliforms, fecal coliforms, and heterotrophic plate counts (HPC) following standard protocols (APHA, ۲۰۱۷). Results revealed pH values within WHO guidelines (۶.۵–۸.۵), but ۱۲% of distribution point samples exceeded the turbidity threshold of ۵ NTU, and residual chlorine levels were consistently low (۰.۱۲–۰.۲۲ mg/L). Microbial contamination was widespread, with total coliforms detected in ۸۲% of samples and fecal coliforms in ۵۵%, particularly at distribution points (۱۶.۲ and ۴.۸ MPN/۱۰۰ mL, respectively). HPC remained below ۵۰۰ CFU/mL but increased from source to distribution, suggesting biofilm formation. Summer months showed higher turbidity and fecal coliforms due to runoff and temperature effects. The Water Quality Index classified six villages as “poor” (WQI < ۷۰) and four as “fair” (WQI ۷۰–۸۰), with spring-based systems performing better. These findings highlight inadequate disinfection, aging infrastructure, and environmental vulnerabilities as key contamination drivers. Urgent interventions, including enhanced chlorination, source protection, and pipe maintenance, are needed to ensure safe drinking water and reduce health risks in rural Sanandaj.

کلیدواژه ها:

Drinking Water Quality ، Microbial Contamination ، Residual Chlorine ، Rural water supply ، Turbidity