Hydrogeochemical Investigation of Surface and Groundwater Quality around Anguwan Maigiru Mining Sites, Niger State, Northcentral Nigeria

Abstract

An investigation of surface and groundwater quality was carried out in Anguwan Maigiru, Madaka District of Rafi Local Government of Niger State, North Central Nigeria. This was aimed at evaluating the quality status of surface and groundwater in the study area. The geological mapping revealed that the area is dominantly underlain by schist and granite. The physical parameters of the collected water samples were determined on site using the appropriate techniques while the chemical analysis was done at Regional Water Quality Laboratory Minna and the National Geosciences Research Laboratory Kuluna. A wide range and standard deviation was observed in the following groundwater quality parameter: Total dissolved solid (54.00-1123.00). electrical conductivity (35.00-1696.00), pll (5.54-10.60), sodium (5.00-471.00), iron (0.10-95.60), zinc (0.03 6.14), copper (0.03-3.13), chromium (0.05-0.36), manganese (0.06-1.36) and lead (0.00-11.00) are signatures that the water sources in the area are deteriorated by enrichment of these parameters. The Piper and Stiff plots show that the water samples analyzed had Na-HCO-CI as the most dominant water type with minor mixed Ca-Na-Cl and Ca-Cl types. Gibbs plot illustrates that majority of the groundwater samples fall within the rock source dominance which suggests that the weathering of rocks primarily controls the major ion chemistry of groundwater in this area. The result of water quality analyses indicates that the surface and groundwater in the area are polluted and unsuitable for drinking and domestic purpuses. The study attributed the poor condition of the water sources in the area to long term environmental abuse in the area arising from artisanal and illegal mining Shallow hand-dug wells should be discouraged and alemative source of groundwater should be provided for the inhabitants. Residents of the area should build their houses miles away from mine site to prevent contamination and inhalation of toxic metals and waste from mine site should be treated before disposal into nearby surface water or farmlands and regulatory agencies should ensure that global minimum mining standard is maintained in every mining site in Nigeria.