Long-term assessment of water quality of Kathmandu University Drinking Water Supply Centre, Nepal

As drinking water quality determines the health and sanitation of any area, it is imperative to assess and monitor the water quality. Kathmandu University Drinking Water Supply Centre (aKUa) was established in 2017 with an aim to provide good quality and processed drinking water to different schools and associated offices of Kathmandu University (KU). The continuous monitoring of physico-chemical and biological water quality parameters was conducted before treatment (BLT) and after treatment (ALT) by the Aquatic Ecology Centre (AEC) of KU from the beginning of 2018 to the end of 2020. Physical parameters such as pH, dissolved oxygen, electrical conductivity, total dissolved solids, turbidity, and temperature were analyzed on a daily basis. Whereas, basic chemical parameters such as ammonia, nitrate, chloride, fluoride, total hardness, and calcium hardness along with biological parameters, total coliform and Escherichia coli were analyzed on a weekly basis. Moreover, heavy metals; iron, cadmium, manganese, and arsenic were analyzed on a yearly basis. From the data obtained by three years of continuous monitoring, the seasonal variation and monthly variation in physico-chemical and microbial parameters of before and after treatment samples were also analyzed. Also, results revealed the analyzed variables were comparable with the National Drinking Water Quality Standards, 2005 of the Government of Nepal and found to be within the permissible limit. Further, the significant difference in before treatment BLT and after treatment ALT was found in various physico-chemical as well as biological parameters. Moreover, Principal Component Analysis (PCA) revealed various principal components contributing to water quality in both BLT and ALT. In conclusion, water supplied by aKUa is suitable to use for drinking purposes. The continuous monitoring of water and effort from the concerned team is key for successful improvement and upkeep of the drinking water quality.