Abstract

The objective of this work is to provide information on the physical and chemical properties of groundwater in Jimeta-Yola area in order to appreciate the impacts of indiscriminate waste disposal practice on the quality of groundwater and to discuss its suitability for human consumption from the water quality index values. This has been determined by collecting groundwater samples from hand-dug wells and boreholes in the dry season and rainy season periods and subjected to physicochemical analysis. The results indicate that electrical conductivity (EC), chloride, nitrate and dissolved oxygen exceeded World Health Organization (WHO) standards in the dry season and chloride, nitrate, dissolved oxygen, total hardness and chromium hexavalent exceeded WHO standards in the rainy season. Spatial distribution of EC, chloride, nitrate and chromium hexavalent in the dry and rainy season indicated that the sources of these contaminants result from point sources such as house hold solid wastes, sewage effluents and wastewater. The overall water quality index (WQI) value in the dry season was 96.4 which indicate good water quality. The overall WQI value in the rainy season was 138.5 which indicate poor water quality. The high value of WQI has been found to be mainly from chloride, nitrate, dissolved oxygen, chromium hexavalent and EC. The source of these contaminants is attributed to anthropogenic origin. The study revealed that the water quality is unfit for human consumption without treatment.

Key words: Groundwater quality, Jimeta-Yola area, water quality index, chemical parameters.