Assessment of water quality of the Nyando River (Muhoroni-Kenya) using the water quality index (WQI) method

Abstract

The quality of a river water is described by the levels of physico-chemical and microbiological parameters. The aim of the study was to determine the water quality of NyandoRiver water from four sampling stations (Muhoroni, Homalime, Kipchui and Wasao) in Muhoroni sub-catchment area and calculate the water quality index (WQI). Physicochemical and microbiological parameters were determined in water samples following standard protocols. The findings were compared with the permissible limits stipulated by the World Health Organization (WHO) and Kenya Standard (KS) for drinking water. The calculated Water Quality Indices(WQI) ranged from 51.88 to 101.13 lying between “poor water quality” and “unsuitable for drinking”.It is determined that TVC, Fe and Mn represent the most effective water quality parameters for calculation of WQI in Nyando River.