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Nigeria, Kano State, Kano

Effects of waste dumps on groundwater in Kano and environs

The effects of waste dumps on the groundwater supply in Kano and the environs are being investigated. Water samples were collected from the ubiquitous hand-dug wells which form the major source of water supply to the Kano populace, as 96 of the samples were analyzed for their cation and anion contents. \r\n\r\nThe chemical analyses revealed the presence of Ca2+, Mg2+, Na+, K+, Fe2+ , etc. as cations while anions include: HCO3-, Cl-, SO42-, NO3-. The chemical analyses also showed that the groundwater is polluted by leachates from the waste dumps because the values of total dissolved solids, conductivity and salinity were very high in wells near the dumpsites. For instance, at the Court Road dumpsite in Kano metropolis, the total dissolved solids in the wells near it were 983mg/l, conductivity 2000 microsiemens and pH 7.8, while at Yanlemu dumpsite, the total dissolved solids was 1240mg/l conductivity 2520 microsiemens and a high chlorine content of 16.2mg/l. The pH ranged from 5.57 to 7.60 though with most values between 6.0-7.0.\r\n\r\nMicrobial analyses showed that the wells are polluted by micro-organisms like Escherichia coli that could cause epidemic of cholera and such gastrointestinal diseases.\r\n\r\nThe Vertical Electrical Sounding (VES) was used to complement the hydrogeological mapping. A total of 24 VES points were chosen based on different lithologies. It was deduced by the VES that the depths of the topsoil (mainly laterites) to the weathered basement, which is the aquifer, varied from 0.4 - 13.1metres. \r\n\r\n\r\nSieve analysis was performed to further complement the study of the groundwater infiltration. The silty, medium and coarse gravels permit passage of rainwater into the vadose zones and thence to the water-table.\r\n\r\nThe state government could reduce reliance on wells especially for domestic use by providing adequate tap water to the populace. Such will increase the quality of life and improve the economy of the area.\r\n

Inserted in the reports are the following maps (1:50,000): Location map, Accessibility map, Drainage map, Geological map, and Wet & Dry Seasons Water Elevation Contour maps.