The Impact of Irrigated Agriculture on Water Quality of Rivers Kongoni and Sirimon, Ewaso Ng’iro North Basin, Kenya

摘要

This study aimed at determining the water quality of River Sirimon and River Kongoni, Ewaso Ng'iro North Basin, Kenya. Water quality analysis of these two rivers was done for a period of 5 months between November 2005 and February 2006. Portable Palintest equipment was used for the chemical analysis. The study established that there were sulphates concentrations of 22 mgL−1 in the Kongoni River water associated with the use of commercial fertilisers as compared to mean values of 7 mgL−1 along Sirimon River; phosphate concentrations were 1.3 mgL−1 in Kongoni and 0.15 mgL−1 in Sirimon and salinity 3 mgL−1 in Kongoni and 0.47 mgL−1 in Sirimon. On average, mean nitrates concentrations of 1.7 mgL−1 were recorded for Kongoni River, which were higher than those recorded for Sirimon River (0.033 mgL−1). These concentration levels were however within the standard levels set by WHO for example 50 mgL−1 for nitrates (WHO 2008). River Kongoni has two major irrigated horticultural farms across it which were likely polluting the river during the time of this study.