The quality of soil in the vicinity of Madaka mining sites were investigated in this study using Environmental Pollution Indices. Geological mapping of the study area indicated that the area was dominated by schist and granite. The static water level measurement revealed a westward groundwater flow direction which also coincides with the regional structural trend of the area. Laboratory analyses of soil and stream sediment were carried out in National Geosciences Research Laboratory Kaduna. The results of the soil analyses revealed high concentrations of mercury, cadmium, lead and arsenic. The results of the laboratory analysis were further elucidated using pollution indices such as geo-accumulation index, contamination factor, degree of contamination, elemental contamination index and metal pollution index. These environmental indices revealed that the soil is seriously polluted with mercury, cadmium and lead, moderately polluted with arsenic, lightly polluted with iron and copper and very lightly polluted with manganese, zinc, nickel and cobalt in the order of: Hg > Cd >Pb> As > Fe > Cu > Mn > Zn > Ni > Co. The mean concentrations of the first four metals (Hg, Cd, Pb and As) exceeds their average crustal abundance, which is an indication of possible pollution. The concentrations map of the analyzed heavy metals indicated a westward decrease in concentration away from the mine sites. This was in agreement with the flow direction and the possible reduction in pollution intensity away from the mine sites could be attributed to the natural attenuation mechanism of soil in the course of groundwater migration as well as hydrogeological attributes of the area. The study recommends that the miners be grouped into association and trained on modern mining techniques that are environmental friendly. The polluted soils in the area should be remediated and proper sensitization on the dangers associated with artisanal mining should be carried out in the area. Periodic monitoring of the soil quality in the area is advocated. Keywords

Soil and groundwater pollutions are worldwide phenomena which result from both natural and anthropogenic sources. In this research, geophysical investigations involving geoelectric survey using ABEM SAS 300 Terrameter was carried out around three active dumpsites in Gusau, Northwestern, Nigeria for hydro-geophysical assessment of the contamination of soil and groundwater. Vertical electrical Soundings (VES) were conducted on the dumpsites by using Schlumberger array with maximum current electrode separations of 180 m. Five VES were conducted on each dumpsite making a total of fifteen VES along three profiles. The field data obtained has been analyzed using WinGlink software which gives an automatic interpretation of apparent resistivity. The VES results revealed three subsurface layers. The geologic sequence beneath the study area is composed of topsoil (clay to sandy-clay, sandy-lateritic), weathered basement, fractured basement and fresh basement.The topsoil has resistivity ranging from 1.5 Ωm to 48.2 mΩ while the thickness vary from 0.47 m to 3.37 m across the profiles. The second layer's resitivity vary from 5.4 Ωm to 144.35 Ωm and their thickness ranges from 1.36 m to 16.93 m. The third geoelectric layer has resisitivity from 70.0 Ωm to 6003.0 Ωm. The results revealed that the top soils in all the dumpsites were characterized by very low resistivity depicting possible pollution and contamination at all dumpsites. The dumpsites are depicted by differential decomposition of waste as zones of advanced decomposition and fresh waste are reflected by low and high resistivity respectively. The second and third layers show moderate to high resistivity values which are indicative of leachate absence. These areas are suitable for groundwater expolration. Findings from the study indicate that there may be possible contamination of shallow groundwater system in the nearest future if proper mitigation measures are not taken into consideration at the dumpsites.Solid wastes are produced on daily basis as a result of direct consequence of inevitable human activities. Refuse contents consist of various kinds of materials like metallic, organic and non-biodegradable materials [1]. The intensity of the human activities has led to increasing volume of solid

This study examines the hydrochemical facies and groundwater flow patterns present in the crystalline basement aquifer of Minna in North Central Nigeria. Their aerial distribution was mapped and attempts to explain the controlling processes responsible for the various facies. Sixteen water samples were collected from wells and analyzed for various parameters including pH, total dissolved solids (TDS), electrical conductivity (Ec), K+, Na+, Ca+, Mg+, Cl-, HCO3-and SO4-using standard procedures of water analysis. The analytical results present the abundance of ions in the following order Na>Mg>Ca>K → Cl>SO4>HCO3. Chloride is the dominant anions found in the groundwater of the study area. Piper trilinear for the study area shows that there is a mixture of two types of water with variable concentrations of major ions. These are Na + K-Cl-SO4 water type and Ca + Mg-Cl-SO4 water types. This means that groundwater in the area is mainly made up of mixtures of the alkaline and alkaline earth metals and predominantly Cl-SO4-water type. Hydrochemical data analysis revealed four sources of solutes. The processes responsible for their enrichment include: chemical weathering, leaching of the overlying sediments, domestic activities, climatic condition and the flow pattern of the aquifer. The factors have contributed to the changes of the groundwater chemistry. Correlation analysis of the data set of hydrochemical constituents in the groundwater suggests that the aquifer is mainly controlled by TDS, Ec, pH, Na and chloride. There is positive strong correlation between Ec and TDS, TDS and Na, Ec and pH which indicates that there is strong evidence of anthropogenic activities on major ions present in the groundwater and weathering of sodium, potassium minerals in the study area. The groundwater flow trends dominantly N-S, NE-SW, NW-SE and somewhat E-W, which suggests that the groundwater in the study area is structurally controlled and the rocks were affected by the Pan-African Orogeny (600 ± 150Ma).

Groundwater contamination has been a worldwide phenomenon. In this research, geoelectric and geochemical surveys were carried out on three active dumpsites in Gusau metropolis for detection of groundwater contamination. Vertical electrical Soundings (VES) were conducted on the dumpsites using Schlumberger array with maximum current electrode separations of 180 m. Five VES were conducted on each dumpsite making a total of fifteen VES along three profiles. Thirty five (35) points were assessed from three wastes dumpsites using portable XRF equipment for the in-situ testing while fifteen (15) representative groundwater samples collected were taken to the laboratory for hydro-geochemical analysis. The field data obtained from VES was analyzed using WinGlink software. The VES results revealed three subsurface layers. The topsoil has resistivity ranging from 1.5Ωm to 48.2 Ωm while the thicknesses vary from 0.47 m to 3.37 m across the profiles. The second layer’s resistivity varies from 5.4 Ωm to 144.35 Ωm and their thicknesses’ ranges from 1.36 m to 16.93 m. The third geoelectric layer has resistivity from 70.0 Ωm to 6003.0 Ωm. The geoelectric results revealed that the top soils in all the dumpsites were characterized by very low resistivity depicting possible pollution and contamination. Environmental pollution models applied to the geochemical dataset revealed Zn, Pb and Cu as moderately contaminants which generally indicated severe potential contamination in the investigated area. While other analytic parameters such as Mn, Cr, Ni and Fe showed low contamination factors. Hydro chemical analysis showed that pH values recorded from the water samples ranged between 7.26 to 8.12 with mean value of 7.50, whereas, recorded Total dissolve solid (TDS) ranged between 377 to 1393mg/L with average concentration of 751.27mg/L. Findings from the study indicated that there may be possible contamination of shallow groundwater system in the nearest future if proper mitigation measures are not taken into consideration at the dumpsites.