Influence of Anthropogenic Activities on Microbial Quality of Surface Water in Subukia Town, Kenya

Abstract

Water quality and quantity is increasingly under threat by human population increase and anthropogenic activities. Momoi and Subukia rivers in Subukia division, Nakuru County are sources of drinking water for the community but receive point and non-point source pollutants mainly from adjacent livestock grazing fields and pit latrines. To understand the impact of anthropogenic activities on river water quality, a study was conducted to assess the microbial water quality from middle to lower reaches of the two rivers between March and May 2012. Water samples were collected twice a month and analysed for microbiological parameters. The Membrane Filtration Method was used to determine total coliforms, E. coli and Salmonella spp as indicators of microbial water quality. In situ measurements of pH and temperature using Wagtech International portable meter and turbidity using Hach 2100P ISO Turbidimeter were done. Results showed that in River Subukia total coliforms (in cfu per 100 ml water) ranged from 2817±528 (mean±se), recorded in March to 8408±1665 in May while for River Momoi they ranged from 4983±1032 in March to 12117±1494 in April. E. coli counts (cfu per 100 ml water) for River Momoi ranged from 1633±280 (mean±se) in March to 3250±723.8 in April and that of River Subukia ranged from 1267±385.3 in March to 2167±544.5 in April. In conclusion, the mean total coliform, E. coli and Salmonella bacteria counts exceeded WHO and NEMA drinking water guidelines. Since the local residents rely on this water for domestic use, there is therefore need for treatment at the point of use and community education on use of appropriate sanitation techniques to minimize pollution from faecal matter.