HYDROGEOCHEMISTRY OF HAND-DUG WELLS OF PART OF THE SOUTH-WESTERN TALLUS SETTLEMENT OF MINNA RIDGE, NORTH-CENTRAL NIGERIA

Abstract

Groundwater hydrogeochemistry of water from hand-dug wells of part of the south-western half of Minna Ridge, North–Central Nigeria has been carried out with the aim to accessing the quality of the water for various domestic purposes especially drinking through physico–chemical and microbiological analysis with APHA (1998) procedures. The results were compared with available standards for drinking water quality (Nigeria Standard for Drinking Water Quality, 2007 and the World Health Organization Standard for Drinking Water Quality, 2006). All the physical parameters determined were generally within tolerable limits except total dissolved solids, conductivity, turbidity, colour and suspended solid values that are higher in some wells than the Nigeria Standard for Drinking Water Quality (2007). In some cases high concentrations of magnesium ion, iron ion and chromium ion were recorded attributable to weathering and dissolution of either the mineral biotite or hornblende or both from the host rock. The high concentration of nitrate and nitrite in some wells could be attributed to poor sanitary habit especially in the southern part where wastes from an abattoir are discarded into open drains. The high total coliform and E-coli recorded in some wells could be as a result of proximity of sceptic tanks and soak-away to these wells. Hydrochemical facies analysis shows that water from the studied area is of the Ca-Mg-Cl water type. Water from the wells in the area investigated is not fit for drinking purposes as they contain at least four contaminants and at most eleven contaminants. They can have negative impact on human health. The water may be for other domestic purposes. Lining of wells with concrete, boiling of water before domestic purposes, sitting of wells far away from septic tanks and good hygiene practice have been advocated for better water quality.