Physico-chemical and bacteriological evaluation of hand-dug wells in major markets in south-western Nigeria

Abstract

Background: Quality of drinking water has always been a major health concern. Lack of access to safely managed water is responsible for high burden of waterborne diseases which disproportionately impact children and equity of women in Nigeria. This study, therefore, assessed the physico-chemical and bacteriological qualities of hand-dug wells in some major markets in Ibadan Southwestern, Nigeria. Methods: Twenty-two (22) water samples from hand-dug wells, measured sequentially along seven major marketswere tested for their physico-chemical and bacteriological characteristics. Following standard sampling procedures, in-situ measurements were taken for total dissolved solute (TDS), pH, electrical conductivity (EC), salinity and temperature. The most probable number – multiple tube technique was used for coliform enumeration in addition to total viable bacteria count (TVBC). Results: Mean pH (7.37±0.47), TDS (597.51±109.06mg/L), EC (748.79±110.67µS/cm), salinity (0.05±0.01mg/L), and temperature (28.75±0.58ºC) for all the marketswere withinWHO permissible limits except pH. High pH may be due to high organic matter content of the water samples. Bacteria genera comprising Esherichiacoli (37.5%), Staphylococcus aureus (25%), Proteus vulgaris (14.6%), Baccilusspp. (12.5%), Pseudomonas aeruginosa (8.3%) and Klebsiella spp. (2.1%).The mean TVBC of 500 to 192,000cfu/ml were higher than the stipulated WHO standard of <1cfu/100ml.The presence of Esherichiacoli in hand-dug well water samples revealed human or animal faecal contamination.Conclusions: Water from these sources, intended for human consumption or washing of food items, maycompromise food safety and pose severe health risks to consumers. The provision of deep tube wells for safe drinking water, periodically testing of the water quality, and education of the users on improved hygiene practices will help in the provision of safe water to the public consumers.Keywords: Water quality, Hand-dug well, Bacteriological analysis, Coliforms,