Impact of Pit Latrines on Groundwater Quality of Fokoslum, Ibadan, Southwestern Nigeria

Insufficient supply of treated water in most of the rural and peri-urban areas of Nigeria has made groundwater a major source of water supply for domestic and other purposes. In theseareas,water demand is fulfilled from shallow wells. The shallow wells are commonly constructed close to pit latrines.A study was therefore conducted to determine the impact of pit latrines on groundwater quality in Foko slum, Southwestern Nigeria. Water quality of shallow wells was assessed within the slum with respect to their distance from fivepit latrines. Water samples were collected from the shallow wells and analyzed for determination of total and faecal coliforms (FC), alkalinity, total dissolved solids (TDS), total suspended solids (TSS), nitrates, electrical conductivity, turbidity and pH.The faecal coliform values were regressed with distance between the pit latrines and the wells. The resulting equation was evaluated to obtain a minimum lateral distance between a pit latrine and shallow well for zero value of microbiological parameters in the wells.
Results showed that the physico-chemical parameters of the water samples were within the World Health Organization (WHO) guidelines for drinking water quality. Nevertheless, biological contaminants exceeded the recommendation of WHO drinking water quality guidelines. Maximum coliform counts enumerated were9300cfu/100ml of water. This study shows that there is an indicator gradient in faecal bacteria with distance from pit latrines, and that pit latrines whichimpact on shallow well water at lateral distances of 19.75m.