Présentations Colloques

Poster
7.02
Session 7.02: Urban Hydrogeology
Soladoye (orateur)
Groundwater Quality and its Sustainability in Ojo Local Government Area of Lagos, Nigeria
**With the absence of pipe borne water supply, residents of Ojo Local Government Area of Lagos, Nigeria depend solely on groundwater for all their water needs. Characterizing the dense network of houses in the newly urbanized area are shallow hand-dug wells built without the supervision of any regulatory agency. Such wells are of concern to the quality of water consumed by the residents and the sustainability of groundwater resources. **The study was designed to assess the quality of groundwater and the interaction of residents with the resource which have implications for future use. Samples collected from 30 hand-dug wells were tested to determine the concentration levels of eleven parameters. Five hundred questionnaires were administered using the simple random sampling technique. Descriptive and inferential statistics were adopted in the analysis.**Results showed that escherichia coli, silica and lead were not detectable in samples. Compared with the Nigerian Standard for Drinking Water, zinc exceeded the 3mg L limits in 13 wells while magnesium exceeded the set limit in all samples. Wells were observed to be vulnerable to further contamination if necessary precautions were not taken. The average depth of wells was 4.43m. The stipulated minimum distance between wells and a potential source of contamination (15m) was adhered to by 25% of the respondents. Domestic activities were carried out around the wells. The required sanitary inspections were not done.**The study shows that urgent steps need to be taken by policy makers so as to preserve groundwater resources for future generations.**
Nigeria