The study relates groundwater quality to land use types in Lagos State. Fourteen samples
were collected from hand dug wells and boreholes, seven each from rural and urban land
uses in the study area. Ten parameters (pH, electrical conductivity, total dissolved solids,
total hardness, calcium, magnesium, chloride, nitrate and sulfate) were determined using
standard methods. The resulting water quality indices revealed that 58.09% of the samples
were rated very poor while 21.73%, 9.08% and 11.1% were rated poor, good and excellent,
respectively in rural land use. The analysis of samples drawn from urban land use revealed
that 76.55% of the water was unfit for drinking while 14.4%, 6.42% and 2.63% were found
to be very poor, good and excellent, respectively. pH, total dissolved solids, chloride, total
hardness and nitrate were beyond the permissible limits for urban land use while, pH, total
hardness and nitrate were above permissible limits for rural land use. These parameters
were found to be responsible for the poor water quality rating in the study areas. The paper
recommends a comprehensive effective sewerage system for safe disposal of sewage,
efficient waste water handling and control of urban runoff to prevent groundwater quality
deterioration in the study areas.