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Environ Monit Assess (2011) 178:477485 DOI 10.1007/s10661-010-1706-y
Ground water quality in the Kathmandu valley of Nepal
Bhoj Raj Pant
Received: 2 November 2009 / Accepted: 6 September 2010 / Published online: 21 September 2010 Springer Science+Business Media B.V. 2010
Abstract A study was undertaken to assess the quality of groundwaters in the Kathmandu Valley, Nepal. The groundwater samples were randomly collected from shallow well, tube well, and deep-tube wells located at different places of Kathmandu, Lalitpur, and Bhaktapur districts in the Kathmandu valley. Physical, chemical, and microbiological parameters of the samples were evaluated to estimate the groundwater quality for drinking water. It was found that the groundwater in the valley is vulnerable to drink due to presence of iron and coliform bacteria. Iron was estimated to be much higher then the acceptable limit of World Health Organization (WHO) drinking-water quality guidelines(1.9 mg/L). Total coliform bacteria enumerated in groundwaters significantly exceeded the drinking-water quality standard and observed maximum coliform (267 CFU/100 mL) in shallow wells. The electrical conductivity and turbidity were found to be 875 S/cm and 55 NTU, respectively, which are above the WHO recommendations for drinking water guidelines. However, pH value was measured within the acceptable limit. Arsenic, chlo-ride, fluoride, and hardness concentrations were
B. R. Pant (B)
Nepal Academy of Science and Technology, G.P.O. Box 3323 Kathmandu, Nepal e-mail: [email protected]
found to be in agreement with the recommendations of WHO drinking-water quality guidelines.
Keywords Kathmandu valley Groundwaters
Sampling Coliform Water quality
Introduction
Kathmandu valley has strongly increasing water demand due to rapid growth of urban population. Treated water supply is limited and insufficient to meet increased water demand for domestic uses. In this circumstance, groundwaters may be a potential source for drinking water in the valley. In Kathmandu valley, about 45% people living in urban or semi-urban areas depend on groundwaters for drinking and other domestic requirements (MOPPW 2003). Generally speaking, groundwater is characterized by low temperature, low redox potential, high carbon dioxide and mineral content, less amount of suspended solids, and free from microbial contaminants. By satisfying the optimum drinking water requirements, groundwater is often considered as the preferred source for public water supply and is also widely explored for private, domestic, and industrial uses.
Recently, rapid urbanization and industrialization have induced...