HYGIENIC ASSESSMENT OF WATER QUALITY IN DOMESTIC DRINKING WATER SUPPLY SYSTEMS OF SAMARKAND

The article provides a comprehensive hygienic evaluation of drinking water quality in both existing and prospective domestic water supply systems of Samarkand. The research analyzes key hydrochemical and microbiological indicators, emphasizing the implications of anthropogenic and abiotic contaminants found in local water sources. The study utilized extensive analytical data derived from over 720 samples collected from wells, clean water reservoirs (CWR), and the Zarafshan River, resulting in approximately 6480 laboratory determinations covering microbiological parameters, toxicological elements, organoleptic properties, and radioactive  contaminants. Results indicate that the groundwater primarily serving Samarkand is generally safe, showing minimal microbial contamination and compliance with established hygienic standards. Groundwater quality has remained consistently high, without significant anthropogenic pollutants detected. However, the assessment revealed a notable deficiency in fluoride concentrations (0.14-0.28 mg/L), raising concerns regarding increased risks of dental caries among the local population. Additionally, certain local water intakes demonstrated increased hardness and mineralization levels due to natural geological processes, particularly noticeable at the Bolibaland and Chupon-ota  water  intakes. The research highlights the necessity for maintaining rigorous sanitary protection measures, especially due to ongoing anthropogenic impacts such as agricultural activities and uncontrolled excavation operations near the water intakes. Furthermore, long-term data analyses (1990-2024) suggest potential fluctuations in groundwater mineralization linked to climatic variations and irrigation practices affecting the Zarafshan River's hydrological regime. Conclusively, the current Samarkand water supply sources are robust and reliable, yet the establishment of additional water intakes, especially near Chubot village on the Zarafshan River, is recommended. This strategic development could significantly enhance the sanitary reliability and long-term sustainability of the city's water supply infrastructure, ensuring public health safety and improving overall water quality management.