BACTERIOLOGICAL QUALITY ASSESSMENT OF DOMESTIC BOREHOLES IN THARAKA NITHI COUNTY, KENYA

Abstract

Water shortage that is caused by long droughts and higher cost of accessing piped water have forced many households in Kenya to opt for wells and borehole water. Where they are used, boreholes are exposed to contaminationbypathogenic microorganismsfrom nearbytoilets,defecationfromdomesticatedanimalsand surface runoff.Despiteofknown healthconcernsofconsumingcontaminated water manyruralresidentsconsumeborehole water whose portability is not determined and may not meet WHO standards. Thus, this study was conducted in Tharaka Nithi County to determine bacterial safety of selected wells and boreholes in Maara, IgambaNgombe and Tharaka Constituencies between March to September 2019. A total of 108 water samples were collected from 36 boreholes. The samples were analyzed at Chuka University using most probable number methods, Plate count and bacteria species identified using selected biochemical methods. Data (MPN) for different locations of study and boreholes were compared using general linear method in SAS. Significance means were separated using least significant difference post hoc test in SAS version 9.4. Number of bacteria isolated from water samples were also compared using general linear model. Feacal coliform values exceeding WHO recommendation of (0 CFU/ 100 ml was observed in all borehole surveyed. Mean MPN value of 17.5/ 100 ml CFU was observed in Kawangware in tharakasouth.ColiformbacteriaE.coli,Bacillusspp,Klebsiellasppwereisolated inallthewatersampled.However, E. coli followed by Bacillus sppwere higher compared to the rest of isolates.Occurrence of these bacteria in borehole water put the health of depended consumers at risk of infection