Mbeke Alexander .,Odipo, O.,Misire, C...(et .al)2025-12-132013http://41.89.103.50:4000/handle/123456789/199Residents of many urban centers including Eldoret are increasingly dependent on groundwater for drinking purposes. This study examined the microbiological suitability of well water available for drinking purposes among residents within Eldoret town. Fifteen sampling stations were established in three residential estates and sampling was done during the wet and dry seasons of the year. The samples were analyzed for the presence of adenosine triphosphate (ATP), using the ATP Microbiotest ® method and confirmed with membrane filtration plate culture method. Results showed that there was a significant difference in the number of bacterial colonies in the sampled sites using the two analytical methods (χ2=0.867, p=<0.001, χ2=3.200, p<0.001) in both the dry and wet seasons respectively. This paper reports high levels of bacterial count during the wet season than in dry season and no significant correlation between relative light units(RLU), Escherichia coliform (E. coli) and distance of the pit latrine from the wells in all three sampled residential estates (p>0.05). The ATP Microbiotest ® method produced relative light unit (RLU) values which correlated positively with colony forming units from plate culture method (r=0.64, p=<0.001). The study also showed that wells in the high density residential areas had the greatest number of bacterial contaminants expressed as ATP than the wells in the low density residential areas. Thus the ATP Microbiotest ® method should adequately be applied in the household rapid screening of microbial well water contaminants. Key words: Microbiotest, RLU, ATP, E. coli, cultureenArticle