This research assessed the sanitary conditions, risk factors and an identification the factors and sources that contribute to pollution of 17 shallow wells located in the Upper Athi River Basin, in Kaimbu County, Kenya using the sanitary assessment inspection methodology prescribed by the World Health Organization. Data obtained from the study was presented and explained using descriptive statistics. One (1) of the shallow wells was in the low risks category (0-4), while seven (7) were found to be in the medium risks category (5-7) with the remaining fourteen (14) falling into the high risk category (8-12). It was also determined that that the location of cattle kraals, farms, pit latrines and solid waste disposal sites in close proximity to shallow wells, coupled with the poor infrastructural nature (shallow wells were not constructed with cement blocks and lacked a an apron and a drainage system around them and were covered with wooden planks) of the shallow wells will possibly allow the introduction and seepage of runoff water and waste water from farms and cattle kraals into the shallow wells. The study recommended that shallow wells should be sited at a minimum safe of 30 m recommended by the WHO away from pit latrines and other sources of pollution.
Keywords: Sanitary risk assessment, shallow wells, groundwater, pollution, pit latrines, cattle kraals water quality, sanitation, sanitary-risk factors